WASTEWATER SUCTION CONTROL METHOD, LIQUID SUCTION SYSTEM, CLEANING BASE STATION, AND CLEANING SYSTEM

Abstract

 The present disclosure provides a sewage extraction control method for a cleaning base station, a liquid extraction system, a cleaning base station and a cleaning system. The cleaning base station comprises a base station body, a cleaning tank arranged at a bottom of the base station body for collecting sewage produced when the cleaning base station cleans cleaning assembly of a self-cleaning device, and a liquid storage container arranged on the base station body for collecting sewage in the cleaning tank. The sewage extraction control method comprises the following steps: closing a sewage extraction channel between the cleaning tank and the liquid storage container; extracting air from the liquid storage container, till the negative pressure in the liquid storage container reaches a preset threshold; opening the sewage extraction channel between the cleaning tank and the liquid storage container; and extracting the sewage from the cleaning tank into the liquid storage container under the action of the negative pressure. The sewage extraction control method can solve the technical problems of noticeable bubbling noise and long duration during sewage extraction from a sewage tank by existing liquid extraction systems.

Description

Cross Reference to Related Applications

[0001] The present application claims the benefits of Chinese Patent Application No. 202411935734.9 filed on Dec. 26, 2024, the content of which is incorporated herein by reference.

Field of the Invention

[0002] The present disclosure relates to the field of cleaning equipment, in particular to a sewage extraction control method, a liquid extraction system, a cleaning base station and a cleaning system.

Background of the Invention

[0003] As an associated assembly of a cleaning device, a cleaning base station generally needs to clean the cleaning assembly of the cleaning device. During the cleaning process, the sewage generally accumulates in a cleaning tank at the bottom of the cleaning base station, and a liquid extraction system is required to extract the sewage into a liquid storage container within the liquid extraction system for storage. In existing cleaning base stations, during the process of extracting sewage from the sewage tank, the liquid extraction system typically applies negative pressure to the liquid storage container while simultaneously using the negative pressure in the liquid storage container to extract sewage from the cleaning tank through a straight pipe. This results in noticeable bubbling noise during the extraction process, and the noise persists for a relatively long duration, affecting user experience. Therefore, it is necessary to provide a sewage extraction control method, a liquid extraction system, a cleaning base station, and a cleaning system to improve the aforementioned issues.

Summary of the Invention

[0004] In view of the drawbacks of the prior art, the present disclosure provides a sewage extraction control method, a liquid extraction system, a cleaning base station and a cleaning system, so as to ameliorate the technical problems of noticeable bubbling noise and long duration during sewage extraction from a sewage tank in a cleaning base station.

[0005] In order to achieve the above object and other related objects, the present disclosure provides a sewage extraction control method for a cleaning base station that comprises a base station body, a cleaning tank arranged at a bottom of the base station body for collecting sewage produced when the cleaning base station cleans cleaning assembly of a self-cleaning device, and a liquid storage container arranged on the base station body for collecting sewage in the cleaning tank. The sewage extraction control method comprises the following steps:

closing a sewage extraction channel between the cleaning tank and the liquid storage container;

extracting air from the liquid storage container, till a negative pressure in the liquid storage container reaches a preset threshold;

opening the sewage extraction channel between the cleaning tank and the liquid storage container; and

extracting the sewage from the cleaning tank into the liquid storage container under the action of the negative pressure.

[0006] In an embodiment of the sewage extraction control method in the present disclosure, the control method further comprises triggering a liquid full prompt when a liquid level in the liquid storage container reaches a first preset height.

[0007] In an embodiment of the sewage extraction control method in the present disclosure, an overflow prevention zone is arranged between the first preset height and the liquid level corresponding to the maximum capacity of the liquid storage container, and the volume of the overflow prevention zone is greater than or equal to the volume of the cleaning tank.

[0008] In an embodiment of the sewage extraction control method in the present disclosure, the volume of the overflow prevention zone is greater than or equal to the volume of liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time.

[0009] In an embodiment of the sewage extraction control method in the present disclosure, whether the liquid level in the liquid storage container reaches the first preset height is determined by detecting the liquid level in the liquid storage container, detecting a weight of the liquid storage container or detecting the number of times of opening and closing of the sewage extraction channel.

[0010] In an embodiment of the sewage extraction control method in the present disclosure, the control method further comprises extracting the sewage produced in cleaning the cleaning assembly in the cleaning tank for a single time into the liquid storage container under the action of the negative pressure when the liquid level in the liquid storage container reaches a second preset height, wherein the second preset height is smaller than the first preset height, and the volume of a zone between the second preset height and the first preset height is smaller than the volume of the cleaning tank.

[0011] In an embodiment of the sewage extraction control method in the present disclosure, the volume of the zone between the second preset height and the first preset height is smaller than the volume of the liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time.

[0012] In an embodiment of the sewage extraction control method in the present disclosure, the preset threshold is positively correlated with the volume of the sewage produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time.

[0013] The present disclosure further provides a liquid extraction system, which comprises: a liquid storage container, a liquid intake pipeline, a first negative pressure device and an on-off assembly, wherein the liquid intake pipeline is in communication with the liquid storage container; a suction port of the first negative pressure device is in communication with the liquid storage container; the on-off assembly is arranged corresponding to the liquid intake pipeline, and has a first state in which the liquid intake pipeline is blocked and a second state in which the liquid intake pipeline is unblocked; wherein when the on-off assembly is switched to the first state, the first negative pressure device evacuates air from the liquid storage container so that the negative pressure in the liquid storage container reaches the preset threshold; and when the on-off assembly is switched to the second state while the negative pressure in the liquid storage container is maintained at the preset threshold, an external liquid is forced to enter the liquid storage container through the liquid intake pipeline under the negative pressure in the liquid storage container.

[0014] In an embodiment of the liquid extraction system in the present disclosure, the on-off assembly comprises a pipeline on-off valve, which comprises a valve body and a valve core, wherein the valve core has a compressed state and an open state, the on-off assembly is in the first state when the valve core is in the compressed state, and the on-off assembly is in the second state when the valve core is in the open state.

[0015] In an embodiment of the liquid extraction system in the present disclosure, the pipeline on-off valve is a pneumatic pinch valve, and the liquid extraction system further comprises a second negative pressure device with an exhaust port in communication with an air inlet of the pneumatic pinch valve, and the air discharged from the second negative pressure device drives the valve core to the compressed state.

[0016] In an embodiment of the liquid extraction system in the present disclosure, the pipeline on-off valve is a pneumatic pinch valve with an air inlet in communication with an exhaust port of the first negative pressure device, and at least a part of the air discharged from the first negative pressure device drives the valve core to the compressed state.

[0017] In an embodiment of the liquid extraction system in the present disclosure, the on-off assembly further comprises a control valve, which comprises an air intake port, a first air outlet port and a second air outlet port, wherein the exhaust port of the first negative pressure device is in communication with the air intake port, the first air outlet port is in communication with the air inlet of the pneumatic pinch valve, and the second air outlet port is in communication with the atmosphere.

[0018] In an embodiment of the liquid extraction system in the present disclosure, the control valve is a two-position three-way solenoid valve.

[0019] In an embodiment of the liquid extraction system in the present disclosure, the on-off assembly further comprises a pressure-limiting valve, which comprises an air inlet and an air outlet, wherein the air inlet of the pressure-limiting valve is in communication with an air outlet of the pneumatic pinch valve, and the air outlet of the pressure-limiting valve is in communication with the atmosphere.

[0020] In an embodiment of the liquid extraction system in the present disclosure, the on-off assembly further comprises a vent valve, which comprises an air intake interface and an air vent interface, wherein the air intake interface is in communication with the air outlet of the pneumatic pinch valve, and the air vent interface is in communication with the atmosphere.

[0021] In an embodiment of the liquid extraction system in the present disclosure, the on-off assembly comprises a pipeline on-off valve, which comprises a valve body and a valve core, wherein the valve core is rotatably arranged in the valve body, the valve body is provided with a valve body flow channel, and the valve core is provided with a valve core flow channel; the on-off assembly is in the first state when a non-valve core flow channel part of the valve core corresponds to the valve body flow channel; and the on-off assembly is in the second state when the valve core flow channel of the valve core corresponds to the valve body flow channel.

[0022] In an embodiment of the liquid extraction system in the present disclosure, the pipeline on-off valve is an electric ball valve.

[0023] In an embodiment of the liquid extraction system in the present disclosure, the on-off assembly comprises a pipeline on-off valve, which comprises a valve body and a valve core, wherein the valve core is movably arranged in the valve body, the valve body has a valve body flow channel, and the valve core has a first position and a second position; the on-off assembly is in the first state when the valve core is in the first position, and the on-off assembly is in the second state when the valve core is in the second position.

[0024] In an embodiment of the liquid extraction system in the present disclosure, the pipeline on-off valve is any of a butterfly valve, a gate valve and an electromagnetic pinch valve.

[0025] In an embodiment of the liquid extraction system in the present disclosure, the liquid intake pipeline comprises a rigid pipe section and a flexible pipe section, and the flexible pipe section passes through the valve core of the pneumatic pinch valve.

[0026] In an embodiment of the liquid extraction system in the present disclosure, the pipeline on-off valve is an electromagnetic pinch valve, the liquid intake pipeline comprises a rigid pipe section and a flexible pipe section, and the flexible pipe section passes through a moving path of the valve core of the electromagnetic pinch valve.

[0027] In an embodiment of the liquid extraction system in the present disclosure, the liquid intake pipeline comprises a straight pipe section extending linearly, and the on-off assembly is arranged corresponding to the straight pipe section of the liquid intake pipeline.

[0028] In an embodiment of the liquid extraction system in the present disclosure, the straight pipe section comprises a first straight pipe section and a second straight pipe section, the interface at one end of the on-off assembly is connected with the first straight pipe section, and the interface at the other end of the on-off assembly is connected with the second straight pipe section.

[0029] In an embodiment of the liquid extraction system in the present disclosure, the time required for switching the on-off assembly from the first state to the second state is 0.3s to 1s.

[0030] In an embodiment of the liquid extraction system in the present disclosure, the liquid extraction system further comprises a pressure relief valve, which is arranged in the liquid storage container, wherein the pressure relief valve is opened when the negative pressure value in the liquid storage container is greater than the preset threshold so that an inner cavity of the liquid storage container is in communication with the atmosphere, and the pressure relief valve is closed to seal the liquid storage container when the negative pressure in the liquid storage container is smaller than or equal to the preset threshold.

[0031] In an embodiment of the liquid extraction system in the present disclosure, the pressure relief valve comprises a pressure relief cavity, a sealing plate and an elastic member, wherein one end of the pressure relief cavity is in communication with the inner cavity of the liquid storage container, and the other end of the pressure relief cavity is provided with a pressure relief port in communication with the atmosphere; one end of the elastic member is mounted on a wall of the pressure relief cavity, and the other end of the elastic member tightly seals the sealing plate on the pressure relief port.

[0032] In an embodiment of the liquid extraction system in the present disclosure, a guide rod is provided on the wall of the pressure relief cavity, and the sealing plate is in sliding fit with the guide rod.

[0033] In an embodiment of the liquid extraction system in the present disclosure, a side of the sealing plate facing the guide rod is provided with a sliding block, one side of the sliding block facing the guide rod is provided with a sliding groove, and an end of the guide rod slides in the sliding groove; alternatively, a side of the sealing plate facing the guide rod is provided with a sliding block, a side of the guide rod facing the sealing plate is provided with a sliding groove, and the sliding block slides in the sliding groove.

[0034] In an embodiment of the liquid extraction system in the present disclosure, a sealing element is arranged on a side of the sealing plate facing away from the elastic member, and a projection of the pressure relief port on the sealing plate is located in an area enclosed by the sealing element.

[0035] The present disclosure further provides a cleaning base station, which comprises a base station body and any of the above-mentioned liquid extraction systems, wherein a bottom of the base station body is provided with a cleaning tank, the liquid extraction system is arranged in the base station body, and one end of the liquid intake pipeline away from the liquid storage container is in communication with the cleaning tank.

[0036] In an embodiment of the cleaning base station in the present disclosure, the cleaning base station further comprises a liquid level detection device, which comprises a detecting element and a sensing element, wherein the detecting element is used for sensing the position of the sensing element, and the sensing element is movably arranged in the liquid storage container and rises with the rise of the liquid level in the liquid storage container; alternatively, the sensing element further rises with the rise of the liquid level in the liquid storage container after the liquid level reaches a preset height.

[0037] In an embodiment of the cleaning base station in the present disclosure, the sensing element has a rotating end and a sensing end, wherein the rotating end is rotatably connected in the liquid storage container, and the sensing end rotates around an axis of rotation of the rotating end to realize movement in the height direction.

[0038] In an embodiment of the cleaning base station in the present disclosure, the detecting element comprises a magnetic element and a Hall sensor, wherein the magnetic element is arranged at the sensing end, and the Hall sensor is arranged in the base station body and corresponds to the magnetic element.

[0039] In an embodiment of the cleaning base station in the present disclosure, the sensing element has the highest sensing position, which is the highest liquid level that the sensing element can sense, and the liquid storage container has the highest capacity surface, which is the liquid level corresponding to a maximum liquid volume that the liquid storage container can store without liquid overflow, and the volume between the highest sensing position and the highest capacity surface is greater than or equal to the volume of the cleaning tank.

[0040] In an embodiment of the cleaning base station in the present disclosure, the volume between the highest sensing position and the highest capacity surface is greater than or equal to the volume of liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time.

[0041] In an embodiment of the cleaning base station in the present disclosure, the cleaning base station further comprises a drainage pipe, wherein one end of the drainage pipe is in communication with the liquid storage container, and the other end of the drainage pipe is a free end, and the drainage pipe is provided with a valve component.

[0042] The present disclosure further provides a cleaning system, which comprises a mobile cleaning device and any of the cleaning base stations described above.

[0043] In the liquid extraction system of the present disclosure, by providing the on-off assembly corresponding to the liquid intake pipeline, the liquid intake pipeline can be cut off, so that a closed space is formed inside the liquid storage container, thereby a great negative pressure can be created in the liquid storage container under the action of the first negative pressure device. Thus, compared with an extraction operation mode that extract sewage while simultaneously extracting air, the number of extraction cycles can be reduced, and a threshold for the negative pressure in the liquid storage container can be set according to the volume of the cleaning tank, so that all sewage in the cleaning tank can be extracted into the liquid storage container in a one-off manner. The sewage extraction rate can be effectively improved, and the time spent for extracting sewage can be reduced; besides, since the number of extraction cycles is decreased, the number of cycles of combination between air and sewage is decreased, and the bubble sounds can be reduced at the same time; in addition, the cleaning base station in the present disclosure can obtain a greater extraction force when compared with the extraction operation mode that extract sewage while simultaneously extracting air, thereby the carrying rate of the impurities deposited in the cleaning tank can be increased, the fouling deposition on the bottom of the cleaning tank can be reduced, and the present disclosure is beneficial to realizing complete maintenance-free of the cleaning tank.

Brief Description of Drawings

[0044] To explain the technical scheme in the embodiments of the present disclosure or in the prior art more clearly, the drawings to be used in the description of the embodiments or the prior art will be introduced below briefly. Obviously, the drawings used in the description below only illustrate some embodiments of the present disclosure, and those having ordinary skills in the art can obtain other embodiments based on these drawings without expending any creative labor.

Fig. 1 is a schematic three-dimensional diagram of an embodiment of the cleaning base station in the present disclosure;

Fig. 2 is a view of an embodiment of the cleaning base station, with a part of the housing removed to expose the internal structure;

Fig. 3 is a schematic structural diagram of the liquid storage container in an embodiment of the cleaning base station in the present disclosure;

Fig. 4 is a schematic structural diagram of the liquid storage container in an embodiment of the cleaning base station in the present disclosure after the cover of the liquid storage container is removed;

Fig. 5 is a partial sectional view of the pressure relief valve in an embodiment of the cleaning base station in the present disclosure;

Fig. 6 is a three-dimensional view of the pressure relief cavity in an embodiment of the cleaning base station in the present disclosure;

Fig. 7 is a schematic diagram of the water and air connections in an embodiment of the cleaning base station in the present disclosure;

Fig. 8 is a schematic diagram of the water and air connections in another embodiment of the cleaning base station in the present disclosure;

Fig. 9 is a schematic diagram of the water and air connections in yet another embodiment of the cleaning base station in the present disclosure;

Fig. 10 is a schematic diagram of the water and air connections in yet another embodiment of the cleaning base station in the present disclosure;

Fig. 11 is a schematic diagram of the water and air connections in yet another embodiment of the cleaning base station in the present disclosure;

Fig. 12 is a schematic diagram of the installation of a liquid level detection device in the liquid storage container in another embodiment of the cleaning base station in the present disclosure; and

Fig. 13 is a flow chart of an embodiment of the sewage extraction control method in the present disclosure.

Reference Numerals

[0045] 10 - cleaning base station; 100 - base station body; 110 - accommodating cavity; 120 - cleaning tank; 300 - liquid extraction system; 310 - liquid storage container; 314 - tank body; 311 - sewage connector; 312 - air extraction hole; 313 - liquid level detection device; 3131 - sensing element; 3132 - rotating end; 3133 - sensing end; 3134 - magnetic element; 320 - tank cover; 321 - pressure relief cavity; 322-first through-hole; 330 - pressure relief valve; 331 - pressure relief cover; 332 - sealing element; 333 - sealing plate; 334 - elastic member; 335 - pressure relief port; 336 - cover plate; 3361 - second through-hole; 337 - sliding block; 338 - guide rod; 339 - sliding groove; 400 - first negative pressure device; 500 - liquid intake pipeline; 510 - straight pipe section; 511 - first straight pipe section; 512 - second straight pipe section; 513 - flexible pipe section; 600 - on-off assembly; 610 - valve body; 611 - first interface; 620 - control unit; 621 - vent valve; 6211 - air intake interface; 6212 - air vent interface; 622 - pipe connector; 623 - pressure-limiting valve; 6231 - air inlet; 6232 - air outlet; 624 - control valve; 6241 - air intake port; 6242 - first air outlet port; 6243 - second air outlet port; 625 - second negative pressure device; 700 - controller.

Detailed Description of the Embodiments

[0046] The embodiments of the present disclosure will be described in specific examples below, and those skilled in the art can easily understand other advantages and efficacies of the present disclosure from the disclosed content of this specification. The present disclosure can also be implemented or applied by means of other different specific embodiments, and various details in the present specification can be modified or changed on the basis of different viewpoints and applications without departing from the spirit of the present disclosure. It may be noted that the embodiments and the features in the embodiments may be combined with each other, provided that there is no conflict among them. It may also be understood that the terms used in the embodiments of the present disclosure are intended to describe specific implementations, but are not intended to limit the scope of protection of the present disclosure. The test methods for which specific conditions are not specified in the following embodiments are usually in accordance with existing conditions or conditions recommended by various manufacturers.

[0047] Where numerical ranges are provided in the embodiments, it may be understood that the two endpoints of each numerical range and any numerical value between the two endpoints can be selected, unless otherwise specified in the present disclosure. Unless otherwise defined, all technical and scientific terms used in the present disclosure are related to the prior art mastered by those skilled in the art and the description of the present disclosure, and any method, device and material in the prior art similar to or equivalent to those described in the embodiments of the present disclosure may be used to implement the present disclosure.

[0048] It may be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only used for the convenience of description, but are not intended to limit the applicable scope of the present disclosure. Changes or adjustments made to their relative relationship without substantially changing the technical content may also be deemed as falling in the applicable scope of the present disclosure.

[0049] Please see Figs. 1-13. The present disclosure provides a sewage extraction control method for a cleaning base station that comprises a base station body, a cleaning tank arranged at the bottom of the base station body for collecting sewage produced when the cleaning base station cleans cleaning assembly of a self-cleaning device, and a liquid storage container arranged on the base station body for collecting sewage in the cleaning tank. The sewage extraction control method comprises the following steps:

S1: closing a sewage extraction channel between the cleaning tank and the liquid storage container;

S2: extracting air from the liquid storage container, till the negative pressure in the liquid storage container reaches a preset threshold;

S3: opening the sewage extraction channel between the cleaning tank and the liquid storage container; and

S4: extracting the sewage from the cleaning tank into the liquid storage container under the action of the negative pressure.

[0050] In the step S1, a variety of means can be utilized to close the sewage extraction channel. For example, an on-off assembly may be arranged on the pipeline of the sewage extraction channel, a valve capable of closing the sewage discharging port of the cleaning tank may be mounted in the cleaning tank, or a valve capable of closing the sewage extraction port on the liquid storage container may be arranged on the liquid storage container. Preferably, in this embodiment, the liquid storage container is arranged at the top of the cleaning base station, and the cleaning tank is arranged at the bottom of the cleaning base station. The liquid storage container is in communication with the bottom of the cleaning tank through a liquid intake pipeline, and the sewage extraction channel comprises an inner cavity of the liquid intake pipeline, and the liquid intake pipeline is partially configured as a soft pipeline, and the soft pipeline section is clamped by means of a pinch valve, so as to realize the control of the closing and opening of the pipeline. In that arrangement, the pollution of the sewage to the on-off assembly can be reduced, and the service life of the on-off assembly can be prolonged.

[0051] In the step S2, after the sewage extraction channel is closed, a closed cavity is formed in the liquid storage container. At this point, the liquid storage container is extracted, and a negative pressure is created inside the liquid storage container. The extraction operation can be completed by means of a negative pressure device built in the cleaning base station or a separate negative pressure device. There is no particular restriction on the specific configuration of the negative pressure device herein. When the negative pressure in the liquid storage container reaches the preset threshold, the air extraction operation is stopped. The value of the preset threshold may be obtained through hydrodynamic calculations or by means of experiments or experience.

[0052] In the step S3, the sewage extraction channel between the cleaning tank and the liquid storage container is opened. In that process, there is no particular restriction on the opening time of the sewage extraction channel in the present disclosure. However, in view that the opening speed of the sewage extraction channel has an important influence on sewage extraction and collection, the pressure at the beginning of extraction will be inadequate, the sewage in the cleaning tank can't be fully extracted out, and even the sewage extraction channel may be blocked, if the opening speed of the sewage extraction channel is too slow. Preferably, in an embodiment of the cleaning base station in the present disclosure, the diameter of the sewage extraction channel is 15 mm to 20 mm, and the opening time of the sewage extraction channel is 0.3s to 1s. Within the range of diameter and the limit of the opening time, the sewage extraction channel will have enough negative pressure suction force when it is fully opened, thereby a better sewage extraction effect can be achieved.

[0053] In the step S4, after the sewage extraction channel between the cleaning tank and the liquid storage container is opened, the sewage in the cleaning tank can be quickly sucked into the liquid storage container under the action of the great negative pressure, thereby the number of sewage extraction cycles can be reduced; the sewage in the cleaning tank can be fully extracted out in a one-off manner by setting the threshold of negative pressure. Thus, the number of cycles of contact between the sewage and air can be decreased, the bubble sounds can be effectively reduced, and the sewage extraction duration can be shortened.

[0054] In an embodiment of the sewage extraction control method in the present disclosure, the control method further comprises triggering a liquid full prompt when the liquid level in the liquid storage container reaches a first preset height, and providing a prompt in the APP installed in the user terminal, for example, "The liquid storage container is full, please empty it timely.". After the liquid full prompt is triggered, the base station body can't clean the cleaning assembly.

[0055] In an embodiment of the sewage extraction control method in the present disclosure, an overflow prevention zone is arranged between the first preset height and the liquid level corresponding to the maximum capacity of the liquid storage container, and the volume of the overflow prevention zone is greater than or equal to the volume of the cleaning tank. It may be noted that the maximum capacity refers to the maximum volume of water that the liquid storage container can hold without sewage overflow from the liquid storage container.

[0056] In an embodiment of the sewage extraction control method in the present disclosure, the volume of the overflow prevention zone is greater than or equal to the volume of liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time. It may be noted that a single time of cleaning covers an entire cleaning process from the start of cleaning of the cleaning assembly to the completion of cleaning of the cleaning assembly.

[0057] In the sewage extraction control method in the present disclosure, whether the liquid level in the liquid storage container reaches the first preset height is determined by detecting the liquid level in the liquid storage container, detecting the weight of the liquid storage container or detecting the number of times of opening and closing of the sewage extraction channel. In an embodiment, a liquid level detection device for detecting the liquid level in the liquid storage container is provided in the liquid storage container. There is no particular restriction on the type of the liquid level detection device in the present disclosure. The liquid level detection device may include, but is not limited to, a magnetic flip level meter, a floating ball level meter, a steel band level meter, a radar level meter, a differential pressure level meter, etc. In this embodiment, the liquid level detection device is a Hall-sensing liquid level sensor, which comprises a detecting element and a sensing element, wherein the sensing element is movably arranged in the liquid storage container and rises with the rise of the liquid level in the liquid storage container, or the sensing element further rises with the liquid level after the liquid level in the liquid storage container reaches the preset height. A Hall-sensing liquid level sensor has high accuracy and strong anti-interference ability.

[0058] In another embodiment of the control method in the present disclosure, whether the liquid level in the liquid storage container reaches the first preset height is determined by detecting the weight of the liquid storage container. In the vertical direction, a pressure sensor is provided on the surface of the base station body contacting with the liquid storage container or the surface of the liquid storage container contacting with the base station body, and the weight of the liquid storage container is detected by means of the pressure sensor. Whenever the sewage collected in the liquid storage container reaches a preset height, the weight of the liquid storage container is essentially the same. However, it may be noted that the pressure sensor has a certain error range in view of the variation of impurities contained in the sewage, for example, an error of ±0.1 kg is allowed.

[0059] In yet another embodiment of the control method in the present disclosure, whether the liquid level in the liquid storage container reaches the first preset height is determined by detecting the number of times the sewage extraction channel is opened and closed. A counter is built in the valve body on the sewage extraction channel, and the number of opening/closing times is counted by means of the counter. The volume of sewage produced in a single time of cleaning of the cleaning assembly in the cleaning tank is quantified (an error of ±10 mL is allowed). For example, if the volume of sewage produced in a single time of cleaning is 150 mL and the volume of water corresponding to the preset height of the liquid storage container is 4.3 L (the maximum capacity of the liquid storage container is 4.5 L), then the first preset height will be reached after extraction for about 28-29 times. It may be noted that a single time of opening/closing may be a single time of opening, a single time of closing, or a time of closing and a time of subsequent opening.

[0060] In an embodiment of the sewage extraction control method in the present disclosure, the control method further comprises extracting the sewage produced in cleaning the cleaning assembly in the cleaning tank for a single time into the liquid storage container under the action of the negative pressure when the liquid level in the liquid storage container reaches a second preset height, wherein the second preset height is smaller than the first preset height, and the volume of a zone between the second preset height and the first preset height is smaller than the volume of the cleaning tank. Specifically, the first preset height is the highest liquid level position that the sensor can detect, i.e., the liquid full alarm level. Since the volume of the zone between the second preset height and the first preset height is smaller than the volume of the cleaning tank, the final liquid level after the sewage in the cleaning tank in a full state is extracted into the liquid storage container will be higher than the first preset height and smaller than the maximum capacity of the liquid storage container. Thus, not only a liquid full alarm can be triggered after the extraction is completed, but also the volume of liquid that can be stored in the liquid storage container with a fixed volume can be increased.

[0061] In another embodiment of the sewage extraction control method in the present disclosure, the volume of the zone between the second preset height and the first preset height is smaller than the volume of the liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time. Since the volume of the zone between the second preset height and the first preset height is smaller than the volume of liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time, the final liquid level after the sewage produced in the cleaning tank in this time is extracted into the liquid storage container will be higher than the first preset height and smaller than the maximum capacity of the liquid storage container. Thus, not only the sewage extraction work for this time can be completed, but also a liquid full alarm can be triggered after the extraction is completed, and the volume of liquid that can be stored in the liquid storage container with a fixed volume can be increased.

[0062] In an embodiment of the sewage extraction control method in the present disclosure, the preset threshold is positively correlated with the volume of the sewage produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time. In that way, a threshold for the negative pressure in the liquid storage container can be set according to the volume of the sewage in the cleaning tank, and all sewage produced in cleaning the cleaning assembly with the cleaning base station can be extracted into the liquid storage container in a one-off manner under the preset negative pressure threshold.

[0063] Please see Figs. 1-12. The present disclosure provides an extraction system 300, a cleaning base station 10 comprising the extraction system 300 and a cleaning system. The extraction system 300 can be applied not only to the cleaning base station 10 for extracting and storing the sewage in a cleaning tank 120, but also to any suitable extraction apparatus, such as an aquarium water replacement device, a dish-washing machine, a cleaning base station 10, or any other apparatus that requires an extraction operation. However, for the convenience of explanation, a cleaning base station 10 will be used as an example in the following description.

[0064] Please see Figs. 1 and 2. The cleaning base station 10 in the present disclosure comprises: a base station body 100, a cleaning tank 120 and a liquid extraction system 300. There is not particular restriction on the shape of the base station body 100. For example, the base station body 100 may be generally rectangular entirely, or rectangular at the lower part and spherical at the top, but it is not limited to these shapes. Preferably the base station body 100 has an attractive appearance and is small in size in view of the requirement for indoor decoration. The base station body 100 usually comprises an accommodating cavity 110, which is arranged at the bottom of the base station body 100 and has an opening for receiving a cleaning device, and has charging terminals that can be electrically connected to a charging apparatus to charge the cleaning device inside the accommodating cavity 110. However, it may be noted that the base station body 100 in the present disclosure may not be provided with charging terminals if charging is required.

[0065] Please see Figs. 1 and 2. The cleaning tank 120 is arranged at the bottom of the base station body 100 and used for cleaning the cleaning assembly of a cleaning device. The cleaning tank 120 may be square, circular or irregular in shape and structure, but it is not limited to these shapes. Preferably, the cleaning tank 120 can at least partially accommodate the cleaning assembly of the cleaning device in the height direction and can clean the cleaning assembly. In the process of cleaning the cleaning assembly of the cleaning device, the cleaning tank 120 will collect and store sewage to prevent the sewage from flowing out and polluting the indoor floor.

[0066] Please see Figs. 4 and 7. The extraction system 300 comprises: a liquid storage container 310, a liquid intake pipeline 500, a first negative pressure device 400 and an on-off assembly 600. There is not particular restriction on the shape and structure of the liquid storage container 310. Preferably, the liquid storage container 310 is easy to manufacture and has enough strength so that it will not be deformed when the negative pressure is extracted to the preset threshold. One end of the liquid intake pipeline 500 is connected to the top of the liquid storage container 310, and the other end of the liquid intake pipeline 500 is connected to the liquid to be extracted, e.g., the sewage in the cleaning tank 120; a suction port of the first negative pressure device 400 is in communication with the liquid storage container 310; the first negative pressure device 400 may be any suitable device that can pump air, such as a vacuum pump, a centrifugal exhaust fan, an axial exhaust fan, a piston pump, etc., but it is not limited to these devices. There is not particular restriction on the communication between the suction port of the first negative pressure device 400 and the liquid storage container 310. For example, an air extraction hole 312 may be formed by drilling a hole in the wall above the highest liquid level of the liquid storage container 310, and the suction port of the first negative pressure device 400 may be directly connected to the air extraction hole 312, or the suction port of the first negative pressure device 400 may be indirectly connected to the air extraction hole 312 through a pipe. The on-off assembly 600 is arranged corresponding to the liquid intake pipeline 500, and has a first state in which the liquid intake pipeline 500 is blocked and a second state in which the liquid intake pipeline 500 is unblocked; when the on-off assembly 600 is switched to the first state, the first negative pressure device 400 will pump air from the liquid storage container 310 till the negative pressure in the liquid storage container 310 reaches the preset threshold; when the on-off assembly 600 is switched to the second state while the negative pressure in the liquid storage container 310 is maintained at the preset threshold, the sewage in the cleaning tank 120 will be sucked into the liquid storage container 310 through the liquid intake pipeline 500 under the action of the negative pressure in the liquid storage container 310. It may be noted that the preset threshold may be selected through by comprehensive calculation according to the volume of the liquid to be extracted, the diameter of the liquid intake pipeline 500 and the extraction distance, or may be obtained through experiments. In view of the diameter of the liquid intake pipeline 500 of an existing cleaning base station 10, the distance from the liquid storage container 310 to the cleaning tank 120 and the volume of the cleaning tank 120, the preset threshold in this embodiment is set to 30 KPa. In addition, in view of the existence of error, slight fluctuations above and below the preset threshold belong to "maintaining", and the slight fluctuations refer to ±10 KPa.

[0067] Please see Figs. 2-4. In an embodiment of the liquid extraction system 300 in the present disclosure, the liquid storage container 310 is arranged on the base station body 100, and the specific position may be determined as required. Preferably, the sewage can be dumped conveniently at the position or the liquid storage container 310 can be removed conveniently at the position. In an embodiment of the cleaning base station 10 in the present disclosure, the liquid storage container 310 is detachably mounted on the upper part of the base station body 100. There is not particular restriction on the shape and structure of the liquid storage container 310. Preferably, the liquid storage container 310 is easy to manufacture and has enough strength so that it will not be deformed when the negative pressure is extracted to the preset threshold. One end of the liquid intake pipeline 500 is in communication with the liquid storage container 310, and the other end of the liquid intake pipeline 500 is in communication with the cleaning tank 120. There is no particular restriction on the structure of the liquid storage container 310 in the extraction system 300 in the present disclosure. In view that the main function of the liquid storage container 310 on the cleaning base station 10 is to collect the sewage in the cleaning tank 120, the liquid storage container 310 on the cleaning base station 10 usually comprises a tank body 314 and a tank cover 320 hermetically installed on the tank body 314, for the purpose of dumping the sewage and cleaning the liquid storage container 310 conveniently. There is no particular restriction on the specific method of installation of the tank cover 320 on the tank body 314, as long as the tank cover 320 can reliably seal the sewage cavity in the tank body 314. For example, the tank cover 320 may be completely separated from the tank body 314, and may be snap-fitted with the tank body 314 by means of a plurality of fasteners, or one side of the tank cover 320 may be rotationally connected to the tank body 314, and the other side may be snap-fitted with the tank body 314 by means of fasteners.

[0068] There is no particular restriction on the type of the on-off assembly 600 in the present disclosure, as long as the liquid intake pipeline 500 can be switched between the first state and the second state. For example, the on-off assembly 600 may be any one or more of manual valve, electric valve, electromagnetic valve, pneumatic pinch valve and hydraulic pinch valve, but it is not limited to these devices. The on-off assembly 600 is mounted on the liquid intake pipeline 500 and/or a corresponding device body, such as the base station body 100. The specific installation form of the on-off assembly 600 on the liquid intake pipeline 500 and/or the base station body 100 may be determined comprehensively according to the type of the liquid intake pipeline 500 and the type of the on-off assembly 600. In an embodiment of the liquid extraction system 300 in the present disclosure, the on-off assembly 600 comprises a pipeline on-off valve, which comprises a valve body 610 and a valve core (not shown), wherein the valve body 610 is mounted on the liquid intake pipeline 500 and/or the corresponding base station body 100; the valve core is connected to the valve body 610 and has an compressed state and an open state; when the valve core is in the compressed state, the on-off assembly 600 is in the first state, and the liquid intake pipeline 500 is closed; when the valve core is in the open state, the on-off assembly 600 is in the second state, and the liquid intake pipeline 500 is in communication with the liquid storage container 310.

[0069] Please see Figs. 2 and 9. In an embodiment of the liquid extraction system 300 in the present disclosure, the pipeline on-off valve is a pneumatic pinch valve, an air inlet of the pneumatic pinch valve is in communication with the exhaust port of the first negative pressure device 400, and at least a part of the air discharged by the first negative pressure device 400 drives the valve core to the compressed state and drives the pneumatic pinch valve to clamp and block the liquid intake pipeline 500. In this arrangement, the pneumatic pinch valve can be driven to act while the first negative pressure device 400 evacuates air from the liquid storage container 310, and the closing and opening of the liquid intake pipeline 500 is realized. By driving the pneumatic pinch valve directly with the first negative pressure device 400, the system design can be simplified and the manufacturing and maintenance costs can be reduced.

[0070] Please see Fig. 11. In an embodiment of the liquid extraction system 300 in the present disclosure, the pipeline on-off valve is a pneumatic pinch valve, and the liquid extraction system 300 further comprises a second negative pressure device 625 with an exhaust port in communication with an air inlet of the pneumatic pinch valve, and the air discharged from the second negative pressure device 625 drives the valve core to the compressed state. With the second negative pressure device 625 that separately supplies air to the pneumatic pinch valve, the opening and closing of the pneumatic pinch valve will not be affected by the action of the first negative pressure device 400, and the pneumatic pinch valve can be closed before the first negative pressure device 400 evacuates air from the liquid storage container 310, so that the creation of negative pressure in the liquid storage container 310 can be accelerated.

[0071] Please see Fig. 9. In an embodiment of the liquid extraction system 300 in the present disclosure, the on-off assembly 600 further comprises a control valve 624, which is a two-position three-way solenoid valve. The control valve 624 comprises an air intake port 6241, a first air outlet port 6242 and a second air outlet port 6243, and the exhaust port of the first negative pressure device 400 is in communication with the air intake port 6241; the first air outlet port 6242 is in communication with the air inlet of the pneumatic pinch valve, and the second air outlet port 6243 is in communication with the atmosphere. It may be noted that those skilled in the art can readily understand that the structure of the control valve 624 may be any other valve structure that has the same function as a two-position three-way solenoid valve.

[0072] Please see Figs. 2, 9 and 10. In an embodiment of the liquid extraction system 300 in the present disclosure, the on-off assembly 600 further comprises a pressure-limiting valve 623, which comprises an air inlet 6231 and an air outlet 6232, wherein the air inlet 6231 is in communication with the air outlet of the pneumatic pinch valve, and the air outlet 6232 is in communication with the atmosphere. The type of the pressure-limiting valves 623 includes but is not limited to safety valve, pressure relief valve, and overflow valve, etc. The pressure-limiting valve 623 can prevent the pressure in the pneumatic pinch valve from exceeding the designed bearing capacity and thereby prevent explosion or breaking, and can effectively protect the pneumatic pinch valve.

[0073] Please see Figs. 2 and 9-11. In an embodiment of the liquid extraction system 300 in the present disclosure, the on-off assembly 600 further comprises a vent valve 621, which comprises an air intake interface 6211 and a vent interface 6232, wherein the air intake interface 6211 is in communication with the air outlet of the pneumatic pinch valve, and the air vent interface 6212 is in communication with the atmosphere. The vent valve 621 can quickly exhaust the air in the pneumatic pinch valve, so as to accelerate the opening of the pneumatic pinch valve.

[0074] In another embodiment of the liquid extraction system 300 in the present disclosure, the on-off assembly 600 comprises a pipeline on-off valve, which comprises a valve body 610 and a valve core (not shown), wherein the valve body 610 is mounted on the liquid intake pipeline 500 and/or the corresponding base station body 100, the valve core is rotatably arranged in the valve body 610, the valve body 610 has a valve body flow channel, and the valve core has a valve core flow channel; when a part of the valve core other than the valve core flow channel corresponds to the valve body flow channel, the on-off assembly 600 is in the first state; when the valve core flow channel of the valve core corresponds to the valve body flow channel, the on-off assembly 600 is in the second state. Such a pipeline on-off valve can close and open the liquid intake pipeline 500 by means of the rotation of the valve core, and it is easy to operate and facilitates further electric control. Preferably, in an embodiment of the extraction system 300 in the present disclosure, the pipeline on-off valve is an electric ball valve. An electric ball valve is a valve that is opened and closed by driving a ball in the valve to rotate with an electric actuator, and it has low cost and high reliability.

[0075] In an embodiment of the liquid extraction system 300 in the present disclosure, the on-off assembly 600 comprises a pipeline on-off valve, which comprises a valve body 610 and a valve core (not shown), wherein the valve body 610 is mounted on the liquid intake pipeline 500 and/or the corresponding base station body 100, and the valve core is movably arranged in the valve body 610; the valve body 610 has a valve body flow channel, and the valve core has a first position and a second position; the on-off assembly 600 is in the first state when the valve core is in the first position; the on-off assembly 600 is in the second state when the valve core is in the second position. In this scheme, the on-off assembly 600 is switched between the first state and the second state by means of the movement of the valve core relative to the valve body 610. Thus, the on-off assembly 600 has a small displacement in the cutting path and has a high response rate. The pipeline on-off valve is any of a butterfly valve, a gate valve and an electromagnetic pinch valve. A butterfly valve is simple to open and close, and is subject to low fluid resistance. The movement direction of the gate of a gate valve is perpendicular to the flow direction of the medium, so it is labor-saving to open and close. The liquid intake pipeline 500 has a flexible pipe section 513, and the valve core of an electromagnetic pinch valve pinches and releases the flexible pipe section by moving between a first position and a second position, thereby realizing the opening and closing of the liquid intake pipeline 500. Compared with other types of electromagnetic valves, the liquid does not contact with the valve core of the electromagnetic pinch valve; therefore, the electromagnetic pinch valve has a long service life.

[0076] The type of the liquid intake pipeline 500 in the present disclosure can be selected according to the type of the on-off assembly 600. Preferably, in an embodiment of the liquid extraction system 300 in the present disclosure, the on-off assembly 600 comprises a valve body 610 and a valve core, wherein the valve body 610 is mounted on the liquid intake pipeline 500 and/or the corresponding base station body 100, and the valve core is connected to the valve body 610 and has a compressed state and an open state. The liquid intake pipeline 500 comprises a rigid pipe section and a flexible pipe section 513. There is no particular restriction on the connection between the rigid pipe section and the flexible pipe section 513, as long as the connection is a reliable hermetic connection. The rigid pipe section is arranged outside the valve core of the pneumatic pinch valve, and the flexible pipe section 513 passes through the valve core of the pneumatic pinch valve. When the valve core is in the compressed state, the valve core presses the flexible pipe section 513, so that the on-off assembly 600 is in the first state, and the liquid intake pipeline 500 is closed; when the valve core is in the open state, the valve core releases the flexible pipe section 513, so that the on-off assembly 600 is in the second state, and the liquid intake pipeline 500 is in communication with the liquid storage container 310. By providing a flexible pipe section 513 and blocking it by pinching it with the valve core, the sewage will not pass through the internal flow channel of the valve core, thereby the valve core will not be corroded and damaged, and the service life of the on-off assembly 600 can be prolonged. In other embodiments, the liquid intake pipeline 500 is divided into two sections, an end of one section is connected to the inlet of the pneumatic pinch valve, and an end of the other section is connected to the outlet of the pneumatic pinch valve, so that the liquid intake pipeline can be closed and opened by switching the valve core of the pneumatic pinch valve between the compressed state and the open state.

[0077] In an embodiment of the liquid extraction system 300 in the present disclosure, the on-off assembly 600 comprises a pipeline on-off valve, which is an electromagnetic pinch valve; the liquid intake pipeline 500 comprises a rigid pipe section and a flexible pipe section 513, and the flexible pipe section 513 passes through the moving path of the valve core of the electromagnetic pinch valve. The valve core of the electromagnetic pinch valve pinches or releases the flexible pipe section 513 in a movement process, so as to close or open the liquid intake pipeline 500.

[0078] Please see Figs. 7-11. In an embodiment of the liquid extraction system 300 in the present disclosure, the liquid intake pipeline 500 comprises a straight pipe section 510 extending linearly, and the on-off assembly 600 is arranged corresponding to the straight pipe section 510 of the liquid intake pipeline 500. By arranging the on-off assembly 600 on the straight pipe section 510, not only the sewage extraction efficiency and the system stability are improved, but also the residue of sewage and the pressure loss at the position of the on-off assembly 600 are reduced. Thus, the operation of the entire cleaning base station 10 is more efficient, more reliable and more economical.

[0079] In the liquid extraction system 300 in the present disclosure, the straight pipe section 510 may be an integral section or formed by a plurality of pipe sections connected together, depending on the structure and the form of installation of the on-off assembly 600. As shown in Fig. 7, in an embodiment of the liquid extraction system 300 in the present disclosure, the liquid intake pipeline 500 comprises a first straight pipe section 511 and a second straight pipe section 512, the interface at one end of the on-off assembly 600 is connected to the first straight pipe section 511, and the interface at the other end of the on-off assembly 600 is connected to the second straight pipe section 512. In the second state, the on-off assembly 600 comprises a straight-through flow channel, the interface at one end of the flow channel is connected to the first straight pipe section 511, and the interface at the other end of the flow channel is connected to the second straight pipe section 512; the first straight pipe section 511, the flow channel and the second straight pipe section 512 are connected with each other to form a sewage channel extending along a vertical straight line. This arrangement can reduce the resistance of the valve body 610, reduce the energy loss when the sewage passes through the valve body 610 in the extraction process, and prevent the sewage from blocking the valve body 610 at the position of the flow channel.

[0080] In an embodiment of the liquid extraction system 300 in the present disclosure, there is no particular restriction on the opening time of the on-off assembly 600. However, in view that the opening speed of the on-off assembly 600 has an important influence on sewage extraction and collection, if the opening speed of the on-off assembly 600 is too slow, the pressure will be inadequate at the beginning of extraction, and the sewage deposited in the cleaning tank 120 can't be completely extracted out, and even the liquid intake pipeline 500 may be blocked. Preferably, in an embodiment of the cleaning base station 10 in the present disclosure, the time required for the on-off assembly 600 to switch from the first state to the second state is 0.3s to 1s. Within the opening time, the flow channel of on-off assembly 600 will have enough negative pressure suction force when it is fully opened, thereby a better sewage extraction effect can be achieved.

[0081] Please see Figs. 3-6. In an embodiment of the liquid extraction system 300 in the present disclosure, the liquid extraction system 300 further comprises a pressure relief valve 330, which is arranged in the liquid storage container 310, wherein the pressure relief valve 330 is opened when the negative pressure value in the liquid storage container 310 is greater than the preset threshold so that the inner cavity of the liquid storage container 310 is in communication with the atmosphere, and the pressure relief valve 330 is closed to seal the liquid storage container 310 when the negative pressure in the liquid storage container 310 is smaller than or equal to the preset threshold. There is no particular restriction on the structure of the pressure relief valve 330 and the form of installation of the pressure relief valve 330 on the liquid storage container 310. For example, the pressure relief valve 330 may be mounted on the tank body 314 above the highest liquid level, or it may be mounted on the tank cover 320. When the negative pressure in the liquid storage container 310 is lower than the preset threshold, the pressure relief valve 330 will be opened to allow air to enter the liquid storage container 310. With the pressure relief valve 330, when the vacuum degree in the liquid storage container 310 is too high, air can be replenished automatically. Thus, the negative pressure in the liquid storage container 310 can be maintained at the preset threshold, and the liquid storage container 310 is effectively protected against damage.

[0082] Please see Figs. 3-6, the pressure relief valve 330 in the present disclosure may employ an existing gas pressure-limiting valve structure and may be obtained by general commercial means. Preferably, as shown in Figs. 5-6, in an embodiment of the liquid extraction system 300 in the present disclosure, the pressure relief valve 330 comprises a pressure relief cavity 321, a pressure relief cover 331, a sealing plate 333 and an elastic member 334, wherein one end of the pressure relief cavity 321 is in communication with the inner cavity of the liquid storage container 310, and the other end of the pressure relief cavity 321 is provided with a pressure relief port 335 in communication with the atmosphere; one end of the elastic member 334 is mounted on the wall of the pressure relief cavity 321, and the other end of the elastic member 334 tightly seals the sealing plate 333 on the pressure relief port 335. There is no particular restriction on the shape of the pressure relief cavity 321. The pressure relief cavity 321 may have a rectangular, cylindrical or irregular shape. In this embodiment, the pressure relief cavity 321 is a cylindrical cavity, and the bottom wall of the pressure relief cavity 321 is provided with a first through-hole 322; the pressure relief cavity 321 is in communication with the inner cavity of the liquid storage container 310 through the first through-hole 322, the pressure relief cover 331 covers the pressure relief cavity 321, and the pressure relief port 335 is formed in the pressure relief cover 331; the pressure relief port 335 is covered with a cover plate 336 to prevent dust from blocking the pressure relief port 335, and the cover plate 336 is provided with a second through-hole 3361, through which the pressure relief port 335 is in communication with the atmosphere. In the present disclosure, the elastic member 334 may be any suitable structure that can provide elastic force to seal the sealing plate 333 on the pressure relief port 335. For example, the elastic member 334 may be a bent elastic plate, or a spring, etc., but it is not limited to these elements. Preferably, in this embodiment, the elastic member 334 is a spring, the lower end of the elastic member 334 is mounted on the wall of the pressure relief cavity 321, and the upper end of the elastic member 334 forces the sealing plate 333 to abut against the pressure relief cover 331 and seals the pressure relief port 335; the sealing plate 333 and the pressure relief cover 331 hermetically abut against each other. In a non-pressure relief state, the sealing plate 333 hermetically abuts against the pressure relief cover 331 under the action of the elastic member 334, and seals the pressure relief port 335. The elastic force of the elastic member 334 that forces the sealing plate 333 to hermetically abut against the pressure relief cover 331 is determined according to the maximum value of the preset threshold of the liquid storage container 310. When the negative pressure in the liquid storage container 310 is greater than the maximum value of the preset threshold, the external air pressure further compresses the elastic member 334, and the pressure relief port 335 is opened to allow air to flow into it; when the negative pressure in the liquid storage container 310 is smaller than or equal to the maximum value of the preset threshold, the sealing plate 333 hermetically abuts against the pressure relief cover 331 under the elastic force of the elastic member 334. In this scheme, the pressure relief control of the pressure relief valve 330 is realized by means of the elastic member 334, and there is no need for any additional electric control connection. Therefore, the safety is high and the cost is low, and it is convenient to open or remove the tank cover 320.

[0083] Please see Figs. 3-6. Although the elastic member 334 in the pressure relief valve 330 in the present disclosure can achieve a movement limiting effect for the sealing plate 333 if the elastic member 334 has high rigidity, preferably, in an embodiment of the liquid extraction system 300 in the present disclosure, a guide rod 338 is provided on the wall of the pressure relief cavity 321, and the sealing plate 333 is in sliding-fit with the guide rod 338, for the stability of the sealing plate 333 during the movement. By means of the sliding-fit between the sealing plate 333 and the guide rod 338, the sealing plate 333 can be mounted stably in the pressure relief cavity 321, and no misalignment will occur in the sliding process of the sealing plate 333, thereby the sealing reliability of the sealing plate 333 is improved.

[0084] Please see Figs. 3-6. In the present disclosure, the sliding-fit between the sealing plate 333 and the guide rod 338 may be realized in a variety of ways. In an embodiment of the liquid extraction system 300 in the present disclosure, a side of the sealing plate 333 facing the guide rod 338 is provided with a sliding block 337, and a side of the sliding block 337 facing the guide rod 338 is provided with a sliding groove 339, and an end of the guide rod 338 slides in the sliding groove 339. Alternatively, in other embodiments, a side of the sealing plate 333 facing the guide rod 338 may be provided with a sliding block 337, and a side of the guide rod 338 facing the sealing plate 333 may be provided with a sliding groove 339, and the sliding block 337 slides in the sliding groove 339. The root part of the guide rod 338 is provided with a circular truncated cone to be fitted with the inner hole of a spring, one end of the spring is sleeved on the sliding block 337, and the other end of the spring is sleeved on the circular truncated cone at the root part of the guide rod 338.

[0085] Please see Figs. 3-6. In the present disclosure, although the hermetic abutment between the sealing plate 333 and the pressure relief port 335 can be realized only by selecting an appropriate material of the sealing plate 333 without the sealing element 332, preferably, in an embodiment of the liquid extraction system 300 in the present disclosure, a sealing element 332 is provided on the side of the sealing plate 333 facing away from the elastic element 334, and the projection of the pressure relief port 335 on the sealing plate 333 is located in an area enclosed by the sealing element 332. In this arrangement, the sealing plate 333, the sealing element 332 and the pressure relief cover 331 form an end face sealing structure with pre-tightening pressure when the sealing plate 333 abuts against the periphery of the pressure relief port 335, and a better sealing effect is achieved when compared with a radial sealing method.

[0086] Please see Figs. 1-2. The present disclosure further provides a cleaning base station 10, which comprises a base station body 100 and any of the above-mentioned liquid extraction systems 300, wherein the cleaning tank 120 is arranged at the bottom of the base station body 100 to clean cleaning assembly of a cleaning device, the liquid extraction system 300 is arranged in the base station body 100, and an end of the liquid intake pipeline 500 away from the liquid storage container 310 is in communication with the cleaning tank 120.

[0087] It may be noted: if the on-off assembly 600 is not provided in the cleaning base station 10, when the liquid intake pipeline 500 is not closed, the sewage will automatically flow into the liquid storage container 310 through the liquid intake pipeline 500 once the negative pressure reaches a pressure at which a part of the sewage can be sucked into the liquid storage container 310 when air is extracted from the liquid storage container 310; at that point, the pressure in the liquid storage container 310 will increase, till the negative pressure in the liquid storage container 310 can't provide a minimum suction force required for sewage extraction; then, the sewage extraction will be interrupted; when the negative pressure in the liquid storage container 310 meets the requirement of extraction a part of the sewage into the liquid storage container 310 as the air extraction continues, the sewage extraction will be resumed. Such an operation cycle is repeated for many times, till the sewage in the cleaning tank 120 is fully removed. In that process, since the sewage extraction is interrupted for many times and the sewage is mixed with air again whenever the sewage extraction is resumed, there are high bubble sounds. In addition, the overall time of the intermittent operations is long. In contrast, in the present disclosure, a higher negative pressure can be accumulated because the sewage extraction channel is closed.

[0088] In the liquid extraction system 300 of the cleaning base station 10 in the present disclosure, by arranging the on-off assembly 600 on the liquid intake pipeline 500 between the liquid storage container 310 and the cleaning tank 120, relative isolation between the liquid storage container 310 and the cavity of the cleaning tank 120 can be realized, so that a higher negative pressure can be formed in the liquid storage container 310 under the action of the first negative pressure device 400, and the sewage in the cleaning tank 120 can be sucked out under the action of the negative pressure. Compared with an operation mode that extract sewage while simultaneously extracting air, the number of times of extraction can be reduced, and a threshold for the negative pressure in the liquid storage container 310 can be set according to the volume of the cleaning tank 120, the diameter of the liquid intake pipeline 500 and the distance from the liquid storage container 310 to the cleaning tank 120, so that all the sewage in the cleaning tank 120 can be sucked into the liquid storage container 310 in an one-off manner. Thus, the sewage extraction speed can be effectively improved, and the time spent for extraction sewage can be reduced. Furthermore, since the number of times of extraction is reduced, the number of times of mixing between air and sewage is decreased, and the bubble sounds can be reduced as well; in addition, the cleaning base station 10 in the present disclosure can obtain a greater extraction force when compared with the extraction operation mode that extract sewage while simultaneously extracting air, thereby the carrying rate of the impurities deposited in the cleaning tank 120 can be increased, the fouling deposition on the bottom of the cleaning tank 120 can be reduced, and the present disclosure is beneficial to realizing complete maintenance-free of the cleaning tank 120.

[0089] Please see Figs. 4 and 12. In an embodiment of the cleaning base station 10 in the present disclosure, the liquid extraction system 300 further comprises a liquid level detection device 313 for detecting the sewage level. There is no particular restriction on the type of the liquid level detection device 313. The liquid level detection device 313 may include, but is not limited to a magnetic flip level meter, a floating ball level meter, a steel band level meter, a radar level meter, and a differential pressure level meter, etc. In this embodiment, the liquid level detection device 313 is a Hall-sensing liquid level sensor. The Hall-sensing liquid level sensor comprises a detecting element and a sensing element 3131, wherein the sensing element 3131 is movably arranged in the liquid storage container 310 and rises with the rise of the liquid level in the liquid storage container 310, or continues to rise with the rise of the liquid level after the liquid level in the liquid storage container 310 reaches a preset height. A Hall-sensing liquid level sensor has high accuracy and strong anti-interference ability.

[0090] In the present disclosure, there is no particular restriction on the form of installation of the sensing element 3131 on the liquid storage container 310 is not limited, as long as the sensing element 3131 moves with the liquid level during the rising of the liquid level and can be sensed by the detecting element when it reaches a preset position. Please see Fig. 12. In an embodiment of the cleaning base station 10 in the present disclosure, the sensing element 3131 has a rotating end 3132 and a sensing end 3133, wherein the rotating end 3132 is rotatably connected in the liquid storage container 310, and the sensing end 3133 rotates around an axis of rotation of the rotating end 3132 to move in the height direction. The detecting element comprises a magnetic element 3134 and a Hall sensor, wherein the magnetic element 3134 is arranged at the sensing end 3133, and the Hall sensor is arranged in the base station body 100 and corresponds to the magnetic element 3134. Since the Hall sensor itself is not in direct contact with the liquid, the risk of corrosion of the sensor components in the liquid medium is greatly reduced, thus the service life of the liquid level meter is prolonged.

[0091] In an embodiment of the cleaning base station 10 in the present disclosure, the sensing element 3131 has the highest sensing position, which is the highest liquid level that the sensing element 3131 can sense, and the liquid storage container 310 has the highest capacity surface, which is the liquid level corresponding to a maximum liquid volume that the liquid storage container 310 can store without liquid overflow, and the volume between the highest sensing position and the highest capacity surface is greater than or equal to the volume of the cleaning tank 120. In that arrangement, when the sensing end 3133 of the liquid level detection device 313 is about to reach the highest sensing level but is not triggered, the sewage produced in the cleaning tank 120 in a single time of cleaning of the cleaning assembly still has to be extracted into the liquid storage tank 310, and the volume between the highest sensing level and the highest capacity surface is greater than or equal to the volume of the cleaning tank 120, to ensure that the liquid storage tank 310 still has enough space to accommodate the sewage produced in a single time of cleaning of the cleaning assembly in the cleaning tank 120 and prevent the sewage overflow from the liquid storage tank 310. After the sewage flows into the liquid storage container 310, the liquid level of the sewage is higher than the highest sensing level of the sensing end 3133 of the liquid level detection device 313, and the liquid level detection device 313 provides a signal feedback to give a liquid full alarm, to remind the sewage dumping work after the sewage extraction is completed.

[0092] In an embodiment of the cleaning base station 10 in the present disclosure, the volume between the highest sensing level and the highest capacity surface is greater than or equal to the volume of the sewage produced in the cleaning tank 120 when the cleaning base station 10 cleans the cleaning assembly for a single time. It may be noted that a single time of cleaning covers an entire cleaning process from the start of cleaning of the cleaning assembly to the completion of cleaning of the cleaning assembly.

[0093] Although the sewage in the liquid storage container 310 can be discharged by dumping in the present disclosure, in one embodiment of the cleaning base station 10 in the present disclosure, the cleaning base station 10 further comprises a drainage pipe (not shown), wherein one end of the drainage pipe is in communication with the bottom of the liquid storage container 310, and the other end of the drainage pipe is a free end, and the drainage pipe is provided with a valve component (not shown). When the liquid storage container 310 is full, the free end of the drainage pipe is inserted into a floor drain, and the drainage pipe is opened by opening the valve component, so that the sewage in the liquid storage container 310 is directly drained into the floor drain. In this arrangement, the burden of manual dumping is alleviated, and a good platform for automatic sewage drainage is provided.

[0094] In view that the sewage in the cleaning base station 10 is corrosive, in an embodiment of the cleaning base station 10 in the present disclosure, the liquid intake pipeline 500 is a rigid corrosion-resistant pipeline, which is fixed on the base station body 100; the on-off assembly 600 is an electric valve, which comprises a control unit 620 and a valve body 610, wherein the valve body 610 is directly mounted on the corrosion-resistant liquid intake pipeline 500, the control unit 620 is rigidly connected to the valve body 610, and neither the control unit 620 nor the valve body 610 is connected to the base station body 100. In another embodiment, the on-off assembly 600 may be mounted only on the base station body 100; alternatively, the on-off assembly may be partially mounted on the base station body 100 and partially mounted on the liquid intake pipeline 500.

[0095] In the cleaning base station 10 in the present disclosure, the on-off assembly 600 may be a manual valve. In this case, it may be unnecessary to include the control unit 620. For the convenience of automatic control, as shown in Figs 7-11, in some embodiments of the cleaning base station 10 in the present disclosure, the on-off assembly 600 comprises a control unit 620 and the valve body 610, wherein the valve body 610 is mounted on the liquid intake pipeline 500, the control unit 620 is mounted on the liquid intake pipeline 500 and/or the base station body 100, and is electrically connected to a controller 700, so as to control the valve body 610 to open and block the liquid intake pipeline 500. In this arrangement, automatic control inside the on-off assembly 600 can be realized, and the operating efficiency and accuracy of the cleaning base station 10 can be improved. It is unnecessary to manipulate the valve body 610 manually, thus the possibility of human errors is decreased.

[0096] Although the control of the valve body 610 can be realized by manually operating the control unit 620, in an embodiment of the cleaning base station 10 in the present disclosure, as shown in Fig. 2, the cleaning base station 10 further comprises a controller 700, which is electrically connected with the control unit 620. The control unit 620 in the on-off assembly 600 can be automatically controlled by means of the controller 700. In that way, the controller 700 can automatically regulate the valve according to a preset program or real-time feedback to realize intelligent control, which is of great significance for improving the level of intelligence and the user experience of the cleaning base station 10. Besides, the electrically connected controller 700 facilitates the integration with other automation systems or monitoring systems for the cleaning base station 10, and facilitates the expansion and upgrade of the system. It may be noted that reference may be made to the existing control method in the field of automations for the way in which the controller 700 controls the opening and closing of the valve body 610 via the control unit 620, and it will not be further detailed here.

[0097] There is no particular restriction on the arrangement of the liquid intake pipeline 500 in the present disclosure. Those skilled in the art can readily understand that a negative pressure up to a preset threshold can be created in the liquid storage container 310 and a greater suction force can be obtained when compared with the existing arrangement in which the liquid storage container 310 is in communication with the cleaning tank 120 directly without the on-off assembly 600, as long as the on-off assembly 600 is arranged on the liquid intake pipeline 500 and the liquid storage container 310 can be closed relative to the cleaning tank 120. However, in order to prevent the sewage from remaining in the liquid intake pipeline 500 and reduce the pressure loss, as shown in Figs. 2 and 9, in an embodiment of the cleaning base station 10 in the present disclosure, the liquid intake pipeline 500 comprises a straight pipe section 510 extending linearly, and the valve body 610 is mounted on the straight pipe section 510. By arranging the valve body 610 on the straight pipe section 510, not only the sewage extraction efficiency and the system stability are improved, but also the residue of sewage and the pressure loss at the valve body 610 are reduced. Thus, the operation of the entire cleaning base station 10 is more efficient, more reliable and more economical.

[0098] Please see Figs. 2, 4 and 9. In an embodiment of cleaning that base station 10 in the present disclosure, the liquid storage container 310 is arranged at the top of the base station body 100, and the straight pipe section 510 is arranged in the vertical direction, the upper end of the straight pipe section 510 is in communication with the sewage connector 311 in the liquid storage container 310, and the lower end of the straight pipe section 510 is in communication with the bottom of the cleaning tank 120. In that arrangement, the lengths of the inclined pipe section and the horizontal pipe section can be reduced, and the blockage caused by deposition of the sewage on the inner wall of the liquid intake pipeline 500 under the action of gravity can be prevented.

[0099] In the present disclosure, the straight pipe section 510 may be an integral section or formed by a plurality of pipe sections connected together, depending on the structure and the form of installation of the valve body 610. As shown in Fig. 7, in an embodiment of the cleaning base station 10 in the present disclosure, the liquid intake pipeline 500 comprises a first straight pipe section 511 and a second straight pipe section 512. In the second state, the valve body 610 comprises a straight-through flow channel, the interface at one end of the flow channel is connected to the first straight pipe section, and the interface at the other end of the flow channel is connected to the second straight pipe section 512, and the first straight pipe section 511, the flow channel and the second straight pipe section 512 are connected with each other to form a sewage channel extending along a vertical straight line. This arrangement can reduce the resistance of the valve body 610, reduce the energy loss when the sewage passes through the valve body 610 in the extraction process, and prevent the sewage from blocking the valve body 610 at the position of the flow channel.

[0100] The materials of the first straight pipe section 511 and the second straight pipe section 512 in the present disclosure can be determined according to the installation requirement of the valve body 610. In an embodiment of the cleaning base station 10 in the present disclosure, both the first straight pipe section 511 and the second straight pipe section 512 are hard pipes, and the two ends of the on-off assembly 600 are respectively connected with the first straight pipe section 511 and the second straight pipe section 512 hermetically via quick connectors. The quick connectors may be in the form of common quick connectors in the hydraulic field, and are commercially available. Therefore, they will not be further detailed here. It may be noted that the first straight pipe section 511 and the second straight pipe section 512 may be connected with the valve body 610 by means of other detachable connections such as flanges, if the quickness of the connections is not a consideration.

[0101] Please see Figs. 8-11. In an embodiment of the cleaning base station 10 in the present disclosure, the liquid intake pipeline 500 comprises a flexible pipe section 513, the valve body 610 of the on-off assembly 600 is a pinch valve, which is mounted on the flexible pipe section 513, and the control unit 620 is mounted on the liquid intake pipeline 500 and/or the base station body 100. The control unit 620 controls the pinch valve to pinch and block the flexible pipe section 513 in the first state and release the flexible pipe section 513 in the second state. The pinch valve may be any of pneumatic pinch valve, hydraulic pinch valve, electromagnetic pinch valve and electric pinch valve, but it is not limited to these devices, as long as it can be mounted on the flexible pipe section 513 and can pinch the flexible pipe section 513 to block the liquid intake pipeline 500. By providing a flexible pipe section 513 and blocking it by pinching it with a pinch valve, the sewage will not pass through the internal flow channel of the valve body 610, thereby the valve body 610 will not be corroded and damaged, and the service life of the valve body 610 can be prolonged.

[0102] The material and specific size of the flexible pipe section 513 in the present disclosure may be suitable to meet the sewage extraction requirement and facilitate the pinch valve to pinch and block the liquid intake pipeline 500. In an embodiment, the flexible pipe section 513 is a silicone tube, and the hardness of the silicone tube is 60-80 degrees, such as 60 degrees, 70 degrees and 80 degrees, or any value between 60 degrees and 80 degrees; the inner diameter of the silicone tube is φ18 mm to φ22 mm, such as φ18 mm, φ20 mm, φ22 mm, or any value between φ18 mm and φ22 mm; and the wall thickness of the silicone tube is 1 mm to 2 mm. Such material selection and size range selection can ensure that the flexible pipe section 513 not only has excellent corrosion resistance and aging resistance, but also has excellent elasticity, so that it can be pinched easily under the action of the pinch valve, and can elastically recover from the deformation after the pinch valve is loosened.

[0103] Please see Fig. 9. In an embodiment of the cleaning base station 10 in the present disclosure, the pinch valve is a pneumatic pinch valve, which comprises a first interface 611 for air intake and exhaust, and the opening and closing of the pneumatic pinch valve are controlled by means of air intaking and exhausting through the first interface 611. The control unit 620 further comprises a pressure-limiting valve 623, a control valve 624 and a vent valve 621. The controller 700 of the cleaning base station 10 is electrically connected with the control valve 624, the vent valve 621 and the first negative pressure device 400 respectively to control the opening and closing of the control valve 624, the vent valve 621 and the first negative pressure device 400. The air inlet of the pressure-limiting valve 623, the first air outlet port 6242 and the air inlet of the vent valve 621 are in communication with the first interface 611 through a pipe connector 622 (a four-way pipe connector); the air outlet of the pressure-limiting valve 623, the second air outlet port of the control valve 624, and the vent port of the pressure-limiting valve 621 are in communication with the atmosphere. The pressure-limiting valve 623 can prevent an excessively high internal pressure in the pneumatic pinch valve. When the sewage in the cleaning tank 120 is to be extracted out, the controller 700 controls the vent valve 621 to close, and controls the control valve 624 to connect the exhaust port of the first negative pressure device 400 to the first interface 611 via the pipe connector 622, and turns on the first negative pressure device 400. The first negative pressure device 400 supplies air to the pneumatic pinch valve and closes the pneumatic pinch valve while it extracts air from the liquid storage container 310. At this point, the control valve 624 is switched so that the first negative pressure device 400 is in communication with the atmosphere; when the negative pressure in the liquid storage container 310 reaches the preset threshold, the first negative pressure device 400 is closed, and the vent valve 621 is opened to vent from the pneumatic pinch valve; the pneumatic pinch valve sucks the sewage in the cleaning tank 120 into the liquid storage container 310 while opening the liquid intake pipeline 500. In this scheme, the pneumatic pinch valve can be protected with the pressure-limiting valve 623, and the action switching of the first negative pressure device 400 in each stage can be realized by the on-off control of the control valve 624. After the pneumatic pinch valve is closed, the exhaust port of the first negative pressure device 400 can be directly in communication with the atmosphere through the switching of the control valve 624. Thus, the pulsating impact of the first negative pressure device 400 on the pneumatic pinch valve in the process of exhausting to the atmosphere can be reduced.

[0104] Please see Fig. 10. In an embodiment of the cleaning base station 10 in the present disclosure, the pneumatic pinch valve comprises a first interface 611 for air intake and exhaust. Unlike the scheme in Fig. 9, the control unit 620 does not comprise a control valve 624, but only comprises a pressure-limiting valve 623 and a vent valve 621 for exhaust. The exhaust port of the first negative pressure device 400, the air inlet of the pressure-limiting valve 623 and the air inlet of the vent valve 621 are in communication with the first interface 611 respectively through a pipe connector 622 (a four-way pipe connector 622); the air outlet of the pressure-limiting valve 623 and the air outlet of the vent valve 621 are in communication with the atmosphere. When the sewage in the cleaning tank 120 is to be extracted out, the first negative pressure device 400 operates and extracts air from the liquid storage tank 310 while providing air pressure for closing the pneumatic pinch valve. When the pneumatic pinch valve is closed and the negative pressure inside the liquid storage tank 310 reaches the preset threshold, the first negative pressure device 400 is closed, and then the vent valve 621 is controlled to open to exhaust from the pneumatic pinch valve. The sewage in the cleaning tank 120 is sucked into the liquid storage tank 310 while the pneumatic pinch valve is opened. In this scheme, the first negative pressure device 400 and the pneumatic pinch valve are controlled in combination to vent to the atmosphere through the vent valve 621. Thus, compared with the scheme in Fig. 9, the circuit is simplified and the cost is reduced.

[0105] Please see Fig. 11. In an embodiment of the cleaning base station 10 in the present disclosure, the pinch valve is a pneumatic pinch valve. Unlike the schemes in Figs. 9 and 10, the control unit 620 comprises a second negative pressure device 625 that drives the pneumatic pinch valve separately, and the second negative pressure device 625 is mounted on the base station body 100. The exhaust port of the second negative pressure device 625 and the air inlet of the vent valve 621 are in communication with the first interface 611 of the pneumatic pinch valve through a pipe connector 622 (a three-way pipe connector 622), the exhaust port of the second negative pressure device 625 and the air outlet of the vent valve 621 are in communication with the atmosphere, and the second negative pressure device 625 drives the pneumatic pinch valve to pinch and block the flexible pipe section 513. When the sewage in the cleaning tank 120 is to be pumped out, the second negative pressure device 625 starts to operate, provides enough air pressure for closing the pneumatic pinch valve, and then stops. After the second negative pressure device 625 stops, the first negative pressure device 400 starts to operate, extracts the negative pressure in the liquid storage container 310 to the preset threshold, and then 400 stops. The vent valve 621 is opened to vent air for the pneumatic pinch valve, and the sewage in the cleaning tank 120 is pumped into the liquid storage container 310 while the pneumatic pinch valve is opened. In this scheme, by providing a second negative pressure device 625 that supplies air to the pneumatic pinch valve separately, the opening and closing of the pneumatic pinch valve will not be affected by the action of the first negative pressure device 400, and the pneumatic pinch valve can be closed before the first negative pressure device 400 extracts air from the liquid storage container 310, so that the creation of negative pressure in the liquid storage container 310 can be accelerated. In addition, in this scheme, a vent valve 621 is provided, and the controller 700 of the cleaning base station 10 can control the opening and closing of the vent valve 621 to realize pressure relief of the pneumatic pinch valve. Thus, the level of automation is higher when compared with a structure in which the pressure of the pneumatic pinch valve is relieved manually.

[0106] The present disclosure further provides a cleaning system, which comprises a mobile cleaning device and any of the cleaning base stations 10 described above. The cleaning base station 10 performs cleaning work for the cleaning assembly of the cleaning device. The mobile cleaning device is configured to walk on the floor to complete the corresponding cleaning operation. In practical application, the mobile cleaning device may be embodied as a sweeping machine, a mopping machine, a sweeping and mopping machine, or other similar products. In order to carry out its necessary cleaning function, the mobile cleaning device at least includes a cleaning component, such as a mop or a roller brush. In order to meet the requirement of the cleaning assembly, the mobile cleaning device may further comprise existing structures such as a spray component, a clean water tank, a battery and walking drive system. The mobile cleaning device may further integrate other functions of the existing mobile cleaning devices according to actual requirements. It may include functions that include, but are not limited to, autonomous travel planning based on sensing components such as accelerometer, gyroscope and odometer, obstacle identification and anti-collision based on devices such as distance sensor and image recognition device, autonomous walking based on mechanical mechanisms such as driving wheels, driven wheels and drivers, human-computer interaction based on physical buttons, virtual buttons, display screen and indicators, energy supply based on a rechargeable battery, and intelligent control based on control circuits or control chips, etc.

[0107] In the liquid extraction system in the present disclosure, with an on-off assembly corresponding to the liquid intake pipeline, the liquid intake pipeline can be cut off, so that a closed space is formed inside the liquid storage container, thereby a great negative pressure can be created in the liquid storage container under the action of the first negative pressure device. Thus, compared with a extraction operation mode that extract sewage while simultaneously extracting air, the number of extraction cycles can be reduced, and a threshold for the negative pressure in the liquid storage container can be set according to the volume of the cleaning tank, so that all sewage in the cleaning tank can be pumped into the liquid storage container in a one-off manner. The sewage extraction rate can be effectively improved, and the time spent for extraction sewage can be reduced; besides, since the number of extraction cycles is decreased, the number of cycles of combination between air and sewage is decreased, and the bubble sounds can be reduced at the same time; in addition, the cleaning base station in the present disclosure can obtain a greater extraction force when compared with the extraction operation mode that extract sewage while simultaneously extracting air, thereby the carrying rate of the impurities deposited in the cleaning tank can be increased, the fouling deposition on the bottom of the cleaning tank can be reduced, and the present disclosure is beneficial to realizing complete maintenance-free of the cleaning tank.

[0108] To sum up, the present disclosure effectively overcomes some practical problems in the prior art, and has high utilization value and significance. The above-mentioned embodiments only illustrate the principle and efficacy of the present disclosure, but are not intended to limit the present disclosure. Those skilled in the art can make modifications or variations to the above embodiments without departing from the spirit and scope of the present disclosure. Therefore, all equivalent modifications or variations made by those having ordinary skills in the technical field without departing from the spirit and technical idea disclosed in the present disclosure may still be covered by the claims of the present disclosure.

Claims

1. A sewage extraction control method for a cleaning base station that comprises a base station body, a cleaning tank arranged at a bottom of the base station body for collecting sewage produced when the cleaning base station cleans cleaning assembly of a self-cleaning device, and a liquid storage container arranged on the base station body for collecting sewage in the cleaning tank, characterized in that the control method comprises the following steps:

closing a sewage extraction channel between the cleaning tank and the liquid storage container;

extracting air from the liquid storage container, till a negative pressure in the liquid storage container reaches a preset threshold;

opening the sewage extraction channel between the cleaning tank and the liquid storage container; and

extracting the sewage from the cleaning tank into the liquid storage container under the action of the negative pressure.

2. The sewage extraction control method for a cleaning base station of claim 1, further comprising triggering a liquid full prompt when a liquid level in the liquid storage container reaches a first preset height.

3. The sewage extraction control method for a cleaning base station of claim 2, wherein an overflow prevention zone is arranged between the first preset height and the liquid level corresponding to the maximum capacity of the liquid storage container, and the volume of the overflow prevention zone is greater than or equal to the volume of the cleaning tank.

4. The sewage extraction control method for a cleaning base station of claim 3, wherein the volume of the overflow prevention zone is greater than or equal to the volume of liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time.

5. The sewage extraction control method for a cleaning base station of claim 2 or 3, wherein whether the liquid level in the liquid storage container reaches the first preset height is determined by detecting the liquid level in the liquid storage container, detecting a weight of the liquid storage container or detecting the number of times of opening and closing of the sewage extraction channel.

6. The sewage extraction control method for a cleaning base station of claim 2 or 3, further comprising extracting the sewage produced in cleaning the cleaning assembly in the cleaning tank for a single time into the liquid storage container under the action of the negative pressure when the liquid level in the liquid storage container reaches a second preset height, wherein the second preset height is smaller than the first preset height, and the volume of a zone between the second preset height and the first preset height is smaller than the volume of the cleaning tank.

7. The sewage extraction control method for a cleaning base station of claim 6, wherein the volume of the zone between the second preset height and the first preset height is smaller than the volume of the liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time.

8. The sewage extraction control method for a cleaning base station of claim 1, wherein the preset threshold is positively correlated with the volume of the sewage produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time.

9. A liquid extraction system that uses the sewage extraction control method of claim 1 to perform a sewage extraction operation on a cleaning tank, the liquid extraction system comprising:

a liquid storage container;

a liquid intake pipeline in communication with the liquid storage container;

a first negative pressure device with a suction port in communication with the liquid storage container;

an on-off assembly arranged corresponding to the liquid intake pipeline, having a first state in which the liquid intake pipeline is blocked and a second state in which the liquid intake pipeline is unblocked;

wherein when the on-off assembly is switched to the first state, the first negative pressure device extracts air from the liquid storage container so that the negative pressure in the liquid storage container reaches the preset threshold; and when the on-off assembly is switched to the second state while the negative pressure in the liquid storage container is maintained at the preset threshold, an external liquid is forced to enter the liquid storage container through the liquid intake pipeline under the negative pressure in the liquid storage container.

10. The liquid extraction system of claim 9, wherein the on-off assembly comprises a pipeline on-off valve, which comprises a valve body and a valve core, wherein the valve core has a compressed state and an open state, the on-off assembly is in the first state when the valve core is in the compressed state, and the on-off assembly is in the second state when the valve core is in the open state.

11. The liquid extraction system of claim 10, wherein the pipeline on-off valve is a pneumatic pinch valve, and the liquid extraction system further comprises a second negative pressure device with an exhaust port in communication with an air inlet of the pneumatic pinch valve, and the air discharged from the second negative pressure device drives the valve core to the compressed state.

12. The liquid extraction system of claim 10, wherein the pipeline on-off valve is a pneumatic pinch valve with an air inlet in communication with an exhaust port of the first negative pressure device, and at least a part of the air discharged from the first negative pressure device drives the valve core to the compressed state.

13. The liquid extraction system of claim 12, wherein the on-off assembly further comprises a control valve, which comprises an air intake port, a first air outlet port and a second air outlet port, wherein the exhaust port of the first negative pressure device is in communication with the air intake port, the first air outlet port is in communication with the air inlet of the pneumatic pinch valve, and the second air outlet port is in communication with the atmosphere.

14. The liquid extraction system of claim 13, wherein the control valve is a two-position three-way solenoid valve.

15. The liquid extraction system of any of claims 11-13, wherein the on-off assembly further comprises a pressure-limiting valve, which comprises an air inlet and an air outlet, wherein the air inlet of the pressure-limiting valve is in communication with an air outlet of the pneumatic pinch valve, and the air outlet of the pressure-limiting valve is in communication with the atmosphere.

16. The liquid extraction system of any of claims 11-13, wherein the on-off assembly further comprises a vent valve, which comprises an air intake interface and an air vent interface, wherein the air intake interface is in communication with the air outlet of the pneumatic pinch valve, and the air vent interface is in communication with the atmosphere.

17. The liquid extraction system of claim 9, wherein the on-off assembly comprises a pipeline on-off valve, which comprises a valve body and a valve core, wherein the valve core is rotatably arranged in the valve body, the valve body is provided with a valve body flow channel, and the valve core is provided with a valve core flow channel; the on-off assembly is in the first state when a non-valve core flow channel part of the valve core corresponds to the valve body flow channel; and the on-off assembly is in the second state when the valve core flow channel of the valve core corresponds to the valve body flow channel.

18. The liquid extraction system of claim 17, wherein the pipeline on-off valve is an electric ball valve.

19. The liquid extraction system of claim 9, wherein the on-off assembly comprises a pipeline on-off valve, which comprises a valve body and a valve core, wherein the valve core is movably arranged in the valve body, the valve body has a valve body flow channel, and the valve core has a first position and a second position; the on-off assembly is in the first state when the valve core is in the first position, and the on-off assembly is in the second state when the valve core is in the second position.

20. The liquid extraction system of claim 19, wherein the pipeline on-off valve is any of a butterfly valve, a gate valve and an electromagnetic pinch valve.

21. The liquid extraction system of claim 11 or 12, wherein the liquid intake pipeline comprises a rigid pipe section and a flexible pipe section, and the flexible pipe section passes through the valve core of the pneumatic pinch valve.

22. The liquid extraction system of claim 19, wherein the pipeline on-off valve is an electromagnetic pinch valve, the liquid intake pipeline comprises a rigid pipe section and a flexible pipe section, and the flexible pipe section passes through a moving path of the valve core of the electromagnetic pinch valve.

23. The liquid extraction system of claim 9, wherein the liquid intake pipeline comprises a straight pipe section extending linearly, and the on-off assembly is arranged corresponding to the straight pipe section of the liquid intake pipeline.

24. The liquid extraction system of claim 23, wherein the straight pipe section comprises a first straight pipe section and a second straight pipe section, the interface at one end of the on-off assembly is connected with the first straight pipe section, and the interface at the other end of the on-off assembly is connected with the second straight pipe section.

25. The liquid extraction system of claim 9, wherein the time required for switching the on-off assembly from the first state to the second state is 0.3s - 1s.

26. The liquid extraction system of claim 9, further comprising a relief valve, which is arranged in the liquid storage container, wherein the relief valve is opened when the negative pressure value in the liquid storage container is greater than the preset threshold so that an inner cavity of the liquid storage container is in communication with the atmosphere, and the relief valve is closed to seal the liquid storage container when the negative pressure in the liquid storage container is smaller than or equal to the preset threshold.

27. The liquid extraction system of claim 26, wherein the relief valve comprises a pressure relief cavity, a sealing plate and an elastic member, wherein one end of the pressure relief cavity is in communication with the inner cavity of the liquid storage container, and the other end of the pressure relief cavity is provided with a pressure relief port in communication with the atmosphere; one end of the elastic member is mounted on a wall of the pressure relief cavity, and the other end of the elastic member tightly seals the sealing plate on the pressure relief port.

28. The liquid extraction system of claim 27, wherein a guide rod is provided on the wall of the pressure relief cavity, and the sealing plate is in sliding fit with the guide rod.

29. The liquid extraction system of claim 28, wherein a side of the sealing plate facing the guide rod is provided with a sliding block, one side of the sliding block facing the guide rod is provided with a sliding groove, and an end of the guide rod slides in the sliding groove; alternatively, a side of the sealing plate facing the guide rod is provided with a sliding block, a side of the guide rod facing the sealing plate is provided with a sliding groove, and the sliding block slides in the sliding groove.

30. The liquid extraction system of claim 27, wherein a sealing element is arranged on a side of the sealing plate facing away from the elastic member, and a projection of the pressure relief port on the sealing plate is located in an area enclosed by the sealing element.

31. A cleaning base station comprising a base station body and the liquid extraction system of any of claims 9-29, wherein a bottom of the base station body is provided with a cleaning tank, the liquid extraction system is arranged in the base station body, and an end of the liquid intake pipeline away from the liquid storage container is in communication with the cleaning tank.

32. The cleaning base station of claim 31, further comprising a liquid level detection device, which comprises a detecting element and a sensing element, wherein the detecting element is used for sensing the position of the sensing element, and the sensing element is movably arranged in the liquid storage container and rises with the rise of the liquid level in the liquid storage container; alternatively, the sensing element further rises with the rise of the liquid level in the liquid storage container after the liquid level reaches a preset height.

33. The cleaning base station of claim 32, wherein the sensing element has a rotating end and a sensing end, wherein the rotating end is rotatably connected in the liquid storage container, and the sensing end rotates around an axis of rotation of the rotating end to realize movement in the height direction.

34. The cleaning base station of claim 33, wherein the detecting element comprises a magnetic element and a Hall sensor, wherein the magnetic element is arranged at the sensing end, and the Hall sensor is arranged in the base station body and corresponds to the magnetic element.

35. The cleaning base station of claim 32, wherein the sensing element has the highest sensing position, which is the highest liquid level that the sensing element can sense, and the liquid storage container has the highest capacity surface, which is the liquid level corresponding to a maximum liquid volume that the liquid storage container can store without liquid overflow, and the volume between the highest sensing position and the highest capacity surface is greater than or equal to the volume of the cleaning tank.

36. The cleaning base station of claim 35, wherein the volume between the highest sensing position and the highest capacity surface is greater than or equal to the volume of liquid produced in the cleaning tank when the cleaning base station cleans the cleaning assembly for a single time.

37. The cleaning base station of claim 31, further comprising a drainage pipe, wherein one end of the drainage pipe is in communication with the liquid storage container, and the other end of the drainage pipe is a free end, and the drainage pipe is provided with a valve component.

38. A cleaning system comprising a mobile cleaning device and the cleaning base station of any of claims 31-36.

Drawing