Drum-type washing machine

Abstract

 A drum-type washing machine of the present invention includes a rotary drum (1); a water tank (3) including the rotary drum (1); a drum pulley (6) securely installed on a rotation shaft (4) of the rotary drum (1); a motor (5) fixed to an outer bottom portion of the water tank (8); a belt (7) that transmits rotation of the motor (5) to the drum pulley (6); a number-of-rotations detection unit (22) for detecting a number of rotations of the motor (5); a lid (11) for opening/closing an opening part of the rotary drum (1); a lid locking device (12) for locking the lid (11) in a closed state; and a controller (17) for executing each process of at least a washing process, a rinsing process, and a dehydrating process. The controller (17) executes control by determining that the belt (7) is broken or disengaged from the drum pulley (6) according to any of a stopping time and the number of rotations of the motor (5).

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a drum-type washing machine for washing laundry loaded in a rotary drum by rotationally driving the rotary drum.

2. Background Art

[0002] Conventional drum-type washing machine and clothes dryer have a configuration in which washing and drying are carried out by transmitting rotation of a motor to a drum pulley via a belt and rotationally driving a rotary drum forwardly or reversely.

[0003] Therefore, in a conventional clothes dryer, when the belt that transmits the rotation of the motor is broken or is disengaged, a part of clothes in the rotary drum is intensively subjected to hot air, clothes that are weak against heat may be discolored or scorched, or, in the worst case, clothes may catch fire.

[0004] In order to solve the above-mentioned problems, clothes dryers having the following configuration is disclosed in, for example, Japanese Patent Unexamined Publication No. H8-215493 (hereinafter, referred to as "Patent Literature 1") and No. H11-179099 (hereinafter, referred to as "Patent Literature 2"). In the configuration, when the number of rotations of a motor reaches a predetermined number, the motor is turned off. When any one of values of the number of pulses until the rotation of the motor stops by inertia and the time until the rotation stops exceeds a set value, it is decided that there is an abnormality, and a user is notified of the abnormality.

[0005] Furthermore, for example, Japanese Patent Unexamined Publication No. H11-114294 (hereinafter, referred to as "Patent Literature 3") discloses an example of a clothes dryer that controls a motor by a predetermined number of rotations, which detects an abnormality of a belt and the like by the following method. More specifically, when it is detected that the motor rotates at an abnormal number of rotations exceeding the predetermined number of rotations, and when the number of rotations of the motor returns to the predetermined number of rotations after the predetermined time has passed after detection of the number of rotations, it is determined that the belt is broken. Furthermore, when the number of rotations of the motor does not return to the predetermined number of rotations, it is determined that control of the motor is abnormal, and a user is notified of the abnormality.

[0006] In this case, the detection methods described in Patent Literatures 1 and 2 are effective in detecting an abnormality of the belt in a drying action of a dryer. However, in a dehydrating action in a washing action that rotates at a higher speed as compared with the time of the drying action, when an abnormality is detected from the inertial action of the motor, it takes time for the motor to stop. As a result, since it takes time to detect an abnormality of a washing machine, there may be problems in safety and reliability.

[0007] In the detection method described in Patent Literature 3, since the motor is driven at an abnormal number of rotations for a predetermined time, when an abnormality is detected in the dehydrating action of the washing machine that rotates at a higher speed than in the drying action in the dryer by the same method as in the drying action, a rotating sound of the motor generates noise, which gives anxiety to a user. Furthermore, if the motor is continuously driven at an abnormal number of rotations for a predetermined time, the motor may be out of order.

[0008] When the belt is broken or the belt is disengaged, even if the motor is braked to stop the rotation of the motor, the rotary drum may be actually rotating. However, a controller of the dryer determines that the rotary drum stops because the motor stops, and unlocks the locked state of a lid. That is to say, before the rotary drum stops, a user may open a lid wrongly.

SUMMARY OF THE INVENTION

[0009] A drum-type washing machine of the present invention includes a rotary drum; a water tank including the rotary drum; a drum pulley securely installed on a rotation shaft of the rotary drum; a motor fixed to an outer bottom portion of the water tank; a belt that transmits rotation of the motor to the drum pulley; a number-of-rotations detection unit for detecting a number of rotations of the motor; a lid for opening/closing an opening part of the rotary drum; a lid locking device for locking the lid in a closed state; and a controller for executing each process of at least a washing process, a rinsing process, and a dehydrating process. The controller executes control by determining that the belt is broken or disengaged from the drum pulley according to any of a stopping time and the number of rotations of the motor.

[0010] Thus, it is possible to accurately detect that the belt is broken or disengaged from the drum pulley. As a result, it is possible to prevent a dangerous state in which the lid is opened during the rotation of the rotary drum in advance.

BRIEF DESCRIPTION OF DRAWINGS

[0011] 

FIG. 1 is a sectional view of a drum-type washing machine in accordance with an exemplary embodiment of the present invention.

FIG. 2 is a view showing the position relation of a water tank, a drum pulley, a motor, and a belt when a main body of the drum-type washing machine is seen from the rear side.

FIG. 3 is a block diagram showing a control unit of the drum-type washing machine.

FIG. 4 is a schematic view illustrating an operation display part of the drum-type washing machine.

FIG. 5 is a first flowchart illustrating control before break of a belt or disengagement of a belt is detected in the drum-type washing machine.

FIG. 6 is a second flowchart illustrating control before break of a belt or separation of a belt is detected in the drum-type washing machine.

FIG. 7 is a third flowchart illustrating control before break of a belt or disengagement of a belt is detected in the drum-type washing machine.

FIG. 8 is a fourth flowchart illustrating control after break of a belt or disengagement of a belt is detected in the drum-type washing machine.

FIG. 9 is a fifth flowchart illustrating control after break of a belt or disengagement of a belt is detected in the drum-type washing

machine.

DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an exemplary embodiment of the present invention is described with reference to drawings. The below-mentioned exemplary embodiment does not limit the present invention.

EXEMPLARY EMBODIMENT

[0013] Hereinafter, a drum-type washing machine in accordance with an exemplary embodiment of the present invention is described with reference to FIGs. 1 and 2.

[0014] FIG. 1 is a sectional view of a drum-type washing machine in accordance with an exemplary embodiment of the present invention. FIG. 2 is a view showing the relation of a water tank, a drum pulley, a motor, and a belt when the drum-type washing machine is seen from the rear side.

[0015] Firstly, as shown in FIG. 1, the drum-type washing machine of this exemplary embodiment includes, within washing machine main body 9, at least water tank (water tub) 3, rotary drum 1 having a bottomed cylindrical shape and being disposed rotatably in water tank 3, and motor 5 installed at the lower part of the outside of water tank 3.

[0016] Rotary drum 1 has a large number of water-flowing holes 2 on the side wall of the outer peripheral part thereof. One end of rotation shaft (rotation center shaft) 4 provided inclining with respect to the center of rotation of rotary drum 1 is fixed to rotary drum 1. The other end of rotation shaft 4 is fixed to drum pulley 6. At this time, rotation shaft 4 is provided from the front side to the rear side as the bottom part in the drum-type washing machine in such a manner that rotation shaft 4 is disposed inclining toward the front upper direction from the horizontal direction.

[0017] Then, as shown in Fig. 2, belt 7 is extended between the rotation shaft of motor 5 and drum pulley 6 provided on water tank 3, and rotation drive of motor 5 is transmitted to drum pulley 6 via belt 7 so as to rotate rotary drum 1 forwardly or reversely.

[0018] Furthermore, on the inner wall surface of rotary drum 1, several protruding plates 8 are provided. Protruding plates 8 raise laundry and drop it from an appropriate height during the rotation of rotary drum 1. Thus, the laundry is washed by the effect of a so-called beat-washing. Water tank 3 is suspended rockably from a top plate of washing machine main body 9 via spring body 10.

[0019] Furthermore, as shown in FIG. 1, an opening part at the front side of rotary drum 1 is provided with lid 11 capable of being opened/closed by lid locking device 12. Lid locking device 12 locks lid 11 in a closed state and prevents a user from wrongly opening lid 11 when rotary drum 1 is rotated.

[0020] Furthermore, to the lower part of water tank 3, one end of drainage hose 13 is connected. Washing water in water tank 3 is drained by drainage pump 14 connected to the other end of drainage hose 13.

[0021] On the upper part of the inside of washing machine main body 9, feed valve 15 for supplying water such as tap water into water tank 3 is provided. The amount of water, which is supplied via feed valve 15 based on information from water level detection unit 30 for detecting a water level in water tank 3 from the water pressure, is controlled by control unit 16.

[0022] With the configuration as mentioned above, the drum-type washing machine of this exemplary embodiment is configured.

[0023] Note here that although not shown in FIGs. 1 and 2, a drying function for drying laundry in rotary drum 1, which includes an air-blowing fan for blowing warm air toward rotary drum 1 and a heater for heating the air, may be provided. Thus, convenience to a user can be improved and a high function of a washing machine can be achieved.

[0024] Hereinafter, a control unit of the drum-type washing machine of this exemplary embodiment is described with reference to FIG. 3.

[0025] FIG. 3 is a block diagram showing a control unit of the drum-type washing machine of this exemplary embodiment.

[0026] As shown in FIG. 3, control unit 16 has controller 17 including, for example, a microcomputer, which controls operations of motor 5, drainage pump 14, and feed valve 15, and the like, and successively controls a series of processes including a washing process, a rinsing process, and a dehydrating process.

[0027] Firstly, controller 17 carries out a display on display part 19 based on information input from input setting part 18 in order to set an operation course, and allows a user to be notified. Then, based on the operation course set by input setting part 18, a start of the operation of the washing machine is set. Specifically, when data are input from water level detection unit 30, lid opening/closing detection unit 31, and the like, into controller 17, actions of lid locking device 12, drainage pump 14, and feed valve 15 are controlled via switching part driving circuit 20 and switching part 21, and the washing operation is started. Herein, when an abnormality occurs, notifying part 25 carries out notification of the abnormality via controller 17.

[0028] Controller 17 controls inverter 24 via inverter driving circuit 23 based on information from number-of-rotations detection unit 22 composed of position detection units 22a, 22b, and 22c for detecting a position of a rotor of motor 5 so as to control the rotation of motor 5. At this time, motor 5 includes, for example, a brushless DC motor, which includes a stator having a three-phase winding (not shown), and the rotor provided with a bipolar permanent magnet in a ring shape. The stator is configured by winding first winding 5a, second winding 5b, and third winding 5c, which constitute the three-phase winding, around an iron core having a slot.

[0029] Furthermore, inverter 24 of control unit 16 is composed of U-phase, V-phase, and W-phase for driving motor 5. Each phase includes a switching element (switching part) having a parallel circuit of a power transistor (insulated gate bipolar transistor (IGBT)) and a reverse conducting diode. Specifically, the U-phase of inverter 24 for driving motor 5 includes a serial circuit of first and second switching elements 24a and 24b; the V-phase includes a serial circuit of third and fourth switching elements 24c and 24d; and the W-phase includes a serial circuit of fifth and sixth switching elements 24e and 24f. Then, the U-phase, V-phase, and W-phase are connected in parallel so as to constitute inverter 24.

[0030] Herein, the both ends of the serial circuit of each switching element constituting the U-phase, V-phase, and W-phase are connected to DC power supply by input terminals. Furthermore, a connecting point of two switching elements in the serial circuit of each switching element constituting the U-phase, V-phase, and W-phase is connected to the respective output terminal. The output terminal is connected to a U-phase terminal, a V-phase terminal, and a W-phase terminal of the three-phase winding of motor 5, controls and outputs the combination of ON and OFF of the two switching elements constituting the U-phase, V-phase, and W-phase of inverter 24. Thus, the U-phase terminal, V-phase terminal, and W-phase terminal of motor 5 achieve three states, i.e., a positive voltage, a zero voltage and a free (open) state.

[0031] Herein, the combination of ON and OFF of the switching element is controlled by controller 17 by the following method based on the information from three position detection units 22a, 22b, and 22c configured by, for example, a Hall IC. Position detection units 22a, 22b, and 22c are disposed at the stator at intervals of an electrical angle of 120 degrees to face the permanent magnet provided in the rotor.

[0032] While the rotor of motor 5 makes one rotation, each of three position detection units 22a, 22b, and 22c outputs a pulse at intervals of an electrical angle of 120 degrees. Controller 17 detects a time point at which any of signal states of three position detection units 22a, 22b, and 22c is changed. Controller 17 changes the combination of ON and OFF of first switching element 24a to sixth switching element 24f based on the detected signals of position detection units 22a, 22b, and 22c. Thus, the U-phase terminal, V-phase terminal, and W-phase terminal of motor 5 are made to be in three states, i.e., a positive voltage, a zero voltage and a free (open) state. As a result, the rotor of motor 5 is rotated by a magnetic field generated by electrification of first winding 5a, second winding 5b, and third winding 5c provided on the stator of motor 5.

[0033] First switching element 24a, third switching element 24c and fifth switching element 24e of inverter 24 are pulse width modulation (PWM) controlled. Specifically, controller 17 controls the number of rotations of the rotor of motor 5 by controlling the electrification ratio of high and low at a repetition frequency of, for example, 10 kHz. That is to say, controller 17 detects a cycle at which a state of a signal of any of three position detection units 22a, 22b, and 22c is changed, and calculates the number of rotations of the rotor of motor 5 from the detected cycle. Then, based on the calculated number of rotations, first switching element 24a, third switching element 24c and fifth switching element 24e of inverter 24 are PWM controlled so that the number of rotations of motor 5 is a set number of rotations.

[0034] At this time, when the rotation speed of rotary drum 1 is accelerated, first switching element 24a to sixth switching element 24f of inverter 24 are PWM controlled so as to have torque in the rotation direction. On the other hand, when the rotation speed of rotary drum 1 is reduced and braked, first switching element 24a to sixth switching element 24f of inverter 24 are PWM controlled so as to have torque in the direction opposite to the rotation direction. Thus, the acceleration or brake (speed reduction) of the rotation speed of rotary drum 1 can be controlled freely.

[0035] Furthermore, as shown in FIG. 3, commercial power supply 26 of control unit 16 is coupled to inverter 24 via DC power supply conversion device 27 including, for example, diode bridge 27a, smoothing capacitors 27b and 27c, and the like.

[0036] With the above-mentioned configuration, control unit 16 of the drum-type washing machine in accordance with this exemplary embodiment is configured.

[0037] Note here that the above-mentioned configuration of control unit 16 is one example, and the configuration of brushless DC motor 5 and the configuration of inverter 24, and the like, are not limited to this configuration.

[0038] Hereinafter, an operation display part for setting an operation course of the drum-type washing machine of this exemplary embodiment is described with reference to FIG. 4.

[0039] FIG. 4 is a schematic view illustrating an operation display part of the drum-type washing machine in this exemplary embodiment. Herein, the operation display part includes at least input setting part 18 and display part 19.

[0040] As shown in FIG. 4, input setting part 18 of the operation display part includes washing time setting switch 18a for setting a washing time, number-of-rinsing-times setting switch 18b for setting a number of rinsing times, dehydrating time setting switch 18c for setting a dehydrating time, drying time setting switch 18d for setting a drying time, course setting switch 18e, start/pause switch 18f, power-on switch 18g, power-off switch 18h, and the like. Furthermore, display part 19 of the operation display part includes washing time display part 19a, number-of-rinsing-times display part 19b, dehydrating time display part 19c, drying time display part 19d, and course setting display part 19e, and the like.

[0041] At this time, controller 17 locks lid 11 in a closed state or unlocks lid 11 by lid locking device 12 shown in FIG. 1 according to the setting of input setting part 18 of the operation display part (for example, in a state in which washing time setting switch 18a is turned on, and power-on switch 18g is turned on). Controller 17 makes it possible to carry out operation of the washing machine when lid 11 is locked by lid locking device 12.

[0042] Furthermore, as mentioned below, controller 17 controls so that lid locking device 12 continues to lock lid 11 in the closed state when the operation is temporarily stopped by the setting of input setting part 18, for example, start/pause switch 18f during operation of the washing machine. Furthermore, also after the operation of the washing machine is finished, controller 17 controls so that lid locking device 12 continues to lock lid 11 in the closed state.

[0043] With the control of the control unit described above, an action of the drum-type washing machine of this exemplary embodiment is controlled.

[0044] Hereinafter, the main point of the present invention, that is, control actions detecting a case in which a belt is broken or a case in which a belt is disengaged are described with reference to FIGs. 5 to 7. Control actions after detecting the case in which the belt is broken or the case in which the belt is disengaged are described with reference to FIGs. 8 and 9.

[0045] FIG. 5 is a first flowchart illustrating control before break of a belt or disengagement of a belt is detected in the drum-type washing machine of this exemplary embodiment.

[0046] As shown in FIG. 5, firstly, when the action of the washing machine is started (step S100), power-on switch 18g of input setting part 18 shown in FIG. 4 is pressed to be turned on (step S101).

[0047] Next, it is decided whether or not start/pause switch 18f of input setting part 18 is turned on (step S102). At this time, when start/pause switch 18f is turned off ("No" in step S102), the process waits until start/pause switch 18f is pressed.

[0048] Then, when start/pause switch 18f of input setting part 18 is pressed to be turned on ("Yes" in step S102), a washing process is started. At this time, lid 11 is controlled by lid locking device 12, and lid 11 is locked in a closed state (step S103).

[0049] Next, it is determined whether or not motor 5 starts a rotation action (step S104). At this time, when motor 5 does not start the rotation action ("No" in step S104), the process waits.

[0050] Next, when motor 5 starts the rotation action ("Yes" in step S104), it is determined whether or not a braking action is carried out during the rotation action of motor 5 (step S105). At this time, when the braking action is not carried out ("No" in step S105), the process waits.

[0051] Next, when the braking action is carried out ("Yes" in step S105), it is decided whether or not the number of rotations of the motor, which is detected by position detection units 22a, 22b, and 22c at the start of the braking action, is a first predetermined number of rotations (for example, 750 rpm (revolutions per minute)) or more (step S106). At this time, the number of rotations of motor 5 is less than the first predetermined number of rotations ("No" in step S106), the process waits.

[0052] Next, the number of rotations of motor 5 is the first predetermined number of rotations or more ("Yes" in step S106), it is decided whether or not a stopping time of motor 5 from the start of braking operation to stopping is shorter than the first predetermined time (for example, one second) (step S107). At this time, when the stopping time of motor 5 from the start of braking to stopping is longer than the first predetermined time ("No" in step S107), it is not determined that the belt is disengaged or the belt is broken, and the process continues (step S109). This is because when the belt does not break, the motor and the rotary drum are linked to each other via the belt, and, therefore, it takes time for the motor to stop even if braking is applied to the motor.

[0053] When the stopping time of motor 5 from the start of the braking action to stopping is shorter than the first predetermined time (for example, one second) ("Yes" in step S107), the disengagement of the belt or the break of the belt is detected (step S108).

[0054] Thus, it can be more easily determined that the belt is broken or disengaged, that is, the belt is disengaged from the drum pulley. Therefore, it is not necessary to add a particular process for detecting that the belt is broken or disengaged, or to extend the process time. As a result, it is possible to accurately detect that the belt is broken or disengaged, and to achieve a drum-type washing machine that is excellent in reliability.

[0055] It is preferable that the above-mentioned first predetermined time is changed and controlled by the number of rotations of motor 5 at the start of braking. For example, when the number of rotations of motor 5 at the start of braking is less than the first predetermined number of rotations 1350 rpm, the first predetermined time is set to one second. Furthermore, the number of rotations of the motor at the start of braking is the first predetermined number of rotations 1350 rpm or more and less than the first predetermined number of rotations 1650 rpm, the first predetermined time is set to 1.5 seconds. Furthermore, when the number of rotations of motor 5 at the start of braking is the first predetermined number of rotations 1650 rpm or more, the first predetermined time is set to 2 seconds.

[0056] More specifically, the first predetermined time is made to be longer when the number of rotations of motor 5 at the start of braking is larger than the first predetermined number of rotations as opposed to when the number of rotations of motor 5 is smaller than the first predetermined number of rotations. Thereby, it is possible to improve the detecting accuracy for detecting the break of the belt or the disengagement of the belt.

[0057] However, needless to say, the first predetermined time and the number of rotations are not limited to the above-mentioned range, they may be arbitrarily set as long as they do not affect a detection action of the washing machine.

[0058] Hereinafter, another control action for detecting a case in which a belt is broken or a case in which a belt is disengaged in the exemplary embodiment of the present invention is described with reference to FIG. 6.

[0059] FIG. 6 is a second flowchart illustrating control before break of a belt or disengagement of a belt is detected in the drum-type washing machine of this exemplary embodiment. As shown in FIG. 6, since the operations from step S100 to step S104 are the same as those in the first flowchart shown in FIG. 5, the description thereof is omitted.

[0060] That is to say, as shown in FIG. 6, when motor 5 starts a rotation action ("Yes" in step S104), it is decided whether or not the number of rotations of the motor, which is detected by position detection units 22a, 22b, and 22c, is a second predetermined number of rotations (for example, 2000 rpm) or more (step S110). At this time, the number of rotations of motor 5 is less than the second predetermined number of rotations ("No" in step S110), it is not determined that the belt is disengaged or the belt is broken, and the process continues (step S112).

[0061] When the number of rotations of motor 5 is the second predetermined number of rotations or more ("Yes" in step S110), the disengagement of the belt or the break of the belt is detected (step S111).

[0062] Thus, when the number of rotations of the motor is larger than the second predetermined number of rotations, the controller easily determines that the belt is broken or the belt is disengaged, that is, the belt is disengaged from the drum pulley more easily. As a result, it is possible to recognize the number of rotations of the motor at the time of normal operation in which failure of the motor due to high-speed rotation does not occur, or in which the break of the belt or the disengagement of the belt does not occur, and to prevent the wrong detection that the belt is broken or the belt is disengaged.

[0063] Hereinafter, still another control action for detecting a case in which a belt is broken or a belt is disengaged in the exemplary embodiment of the present invention is described with reference to FIG. 7.

[0064] FIG. 7 is a third flowchart illustrating control before break of a belt or disengagement of a belt is detected in the drum-type washing machine of this exemplary embodiment. As shown in FIG. 7, since the operations from step S100 to step S104 are the same as those in the flowchart shown in FIG. 5 or FIG. 6, the description thereof is omitted.

[0065] That is to say, as shown in FIG. 7, when motor 5 starts a rotation action ("Yes" in step S104), it is decided whether or not the number of rotations of motor 5 for controlling to drive the rotation of rotary drum 1 is controlled by a third predetermined number of rotations (for example, 30 to 60 rpm (number of rotations of rotary drum 1) (step S113). At this time, when the number of rotations of motor 5 is not controlled by the third predetermined number of rotations ("No" in step S113), the process waits.

[0066] Next, when the number of rotations of rotary drum 1 is controlled by the third predetermined number of rotations by the motor ("Yes" in step S113), it is decided whether or not the number of rotations of motor 5, which is detected by position detection units 22a, 22b, and 22c, is a fourth predetermined number of rotations (for example, 1000 rpm) or more (step S114). At this time, when the number of rotations of motor 5 is less than the fourth predetermined number of rotations ("No" in step S114), it is not determined that the belt is broken or the belt is disengaged, and each washing process is continuously executed according to the operation course (step S116).

[0067] When the number of rotations of motor 5 is the fourth predetermined number of rotations or more ("Yes" in step S114), the disengagement of the belt or the break of the belt is detected (step S115).

[0068] Thus, when the controller detects that motor 5 rotates faster than the fourth predetermined number of rotations in the case where motor 5 controls the rotation of rotary drum 1 to rotate at the third predetermined number of rotations, it determines that the belt is broken or the belt is disengaged, that is, the belt is disengaged from the drum pulley. As a result, it is possible to increase the opportunities for detecting the break of the belt or the disengagement of the belt.

[0069] Note here that it is preferable that the fourth predetermined number of rotations of motor 5 for detecting the break of the belt or the disengagement of the belt is changed by the third predetermined number of rotations of motor 5 for controlling to drive the rotation of rotary drum 1. For example, other than the above, when the third predetermined number of rotations of motor 5 for controlling to drive the rotation of rotary drum 1 is 60 to 150 rpm, the fourth predetermined number of rotations of motor 5 is set to 1200 rpm. Furthermore, when the third predetermined number of rotations of motor 5 for controlling to drive the rotation of rotary drum 1 is 150 to 750 rpm, the fourth predetermined number of rotations of motor 5 is set to 1500 rpm. Furthermore, when the third predetermined number of rotations of motor 5 for controlling to drive the rotation of rotary drum 1 is 750 rpm or more, the fourth predetermined number of rotations of motor 5 is set to 2000 rpm.

[0070] However, it is needless to say that the values are not limited to the above-mentioned range as long as the relation that the fourth predetermined number of rotations of motor 5 is set to be larger as the third predetermined number of rotations of motor 5 for controlling to drive the rotation of rotary drum 1 becomes larger is secured. The value may be arbitrarily set as long as it does not affect the detection operation of the washing machine.

[0071] Thus, it is possible to increase the opportunities for detecting the break of the belt or the disengagement of the belt with respect to any numbers of rotations of the motor for rotating the rotary drum in various washing processes.

[0072] Hereinafter, in the control actions shown in FIG. 5 to FIG. 7, the control actions after the break of the belt or the disengagement of the belt is detected are described with reference to FIGs. 8 and 9. In FIGS. 8 and 9, in order to facilitate the understanding of the determination at the time of detecting the break of the belt or the disengagement of the belt, the description is partially repeated.

[0073] FIG. 8 is a fourth flowchart illustrating control after the break of the belt or the disengagement of the belt is detected in the drum-type washing machine of this exemplary embodiment.

[0074] As shown in FIG. 8, control after the break of the belt or the disengagement of the belt is detected in the drum-type washing machine is started (step S200).

[0075] Next, it is decided whether or not the break of the belt or the disengagement of the belt is detected (step S201). At this time, when the break of the belt or the disengagement of the belt is not detected ("No" in step S201), the process waits.

[0076] Next, when the break of the belt or the disengagement of the belt is detected ("Yes" in step S201), a user is notified of an abnormality that the belt is broken or the belt is disengaged (step S202). At this time, examples of a method of notifying a user include notification with a sound generating device such as a beeper, notification by blinking display part 19, notification by displaying an error number such as a failure mode, and the like.

[0077] Next, it is determined whether or not a second predetermined time (for example, 5 minutes) has passed after detecting the break of the belt or the disengagement of the belt (step S203). When the second predetermined time has not passed ("No" in step S203), the process waits until the second predetermined time has passed. At this time, lid locking device 12 continues to lock lid 11 in a closed state until the second predetermined time has passed. This is carried out to wait until the rotation by inertia of rotary drum 1 stops after the belt is broken or the belt is disengaged.

[0078] Next, when the second predetermined time has passed ("Yes" in step S203), lid locking device 12 controls to unlock the lid (step S204). This makes it possible to open lid 11 and to take out laundry and the like from rotary drum 1.

[0079] That is to say, as shown in FIG. 8, when the break of the belt or the disengagement of the belt is detected, the controller controls so that the locked state of the lid is maintained by lid locking device 12 until the second predetermined time has passed and the lid is unlocked by the lid locking device after the second predetermined time has passed. Thus, when the belt is broken or the belt is disengaged, even if the action of the washing operation in the washing process is interrupted, the lid is locked until the rotation of the rotary drum stops. As a result, a dangerous state in which the lid is opened during the rotation of the rotary drum is prevented in advance, and a drum-type washing machine that is safe and excellent in reliability can be achieve d.

[0080] Hereinafter, yet another the control action after detecting a case in which a belt is broken or a case in which a belt is disengaged in the exemplary embodiment of the present invention is described with reference to FIG. 9.

[0081] FIG. 9 is a fifth flowchart illustrating control after the break of the belt or the disengagement of the belt is detected in the drum-type washing machine of this exemplary embodiment. As shown in FIG. 9, since the operations from step S200 to step S202 are the same as those in the flowchart shown in FIG. 8, the description thereof is omitted.

[0082] That is to say, as shown in FIG. 9, when the break of the belt or the disengagement of the belt is detected ("Yes" in step S201), a user is notified of an abnormality that the belt is broken or the belt is disengaged (step S202).

[0083] Next, it is determined whether or not power-off switch 18h of input setting part 18 is pressed to be turned on (step S205).

[0084] When power-off switch 18h of input setting part 18 is turned on ("Yes" in step S205), power supply of a washing machine is not disconnected (not turned off), and the closed state of lid 11 is maintained by lid locking device 12 (step S206).

[0085] Next, it is determined whether or not a third predetermined time (for example, 5 minutes) has passed after the break of the belt or the disengagement of the belt is detected (step S207).

[0086] When the third predetermined time has not passed ("No" in step S207), the process waits until the third predetermined time has passed. At this time, lid locking device 12 continues to lock the closed state of lid 11 until the third predetermined time has passed. This is carried out to wait until the rotation by inertia of rotary drum 1 stops after the belt is broken or the belt is disengaged.

[0087] Next, when the third predetermined time has passed ("Yes" in step S207), lid locking device 12 controls to unlock the lid (step S208). This makes it possible to open lid 11 and to take out laundry and the like from rotary drum 1.

[0088] Then, the power supply of the washing machine is turned off (step S209).

[0089] Furthermore, when the power-off switch 18h of input setting part 18 is not turned on ("No" in step S205), as described with reference to the flowchart in FIG. 8, it is determined whether or not the second predetermined time (for example, 5 minutes) has passed after the break of the belt or the disengagement of the belt is detected (step S203). When the second predetermined time has not passed ("No" in step S203), the process waits until the second predetermined time has passed. At this time, lid locking device 12 continues to lock lid 11 in a closed state until the second predetermined time has passed. This is carried out to wait until the rotation by inertia of rotary drum 1 stops after the belt is broken or the belt is disengaged.

[0090] Next, when the second predetermined time has passed ("Yes" in step S203), lid locking device 12 controls to unlock the lid (step S204). This makes it possible to open lid 11 and to take out laundry and the like from rotary drum 1.

[0091] That is to say, as shown in FIG. 9, when the break of the belt or the disengagement of the belt is detected, even if a user sets power-off, a power-on state is maintained until the third predetermined time has passed. After the third predetermined time has passed, the power supply is controlled to be turned off. Thus, until the third predetermined time has passed, the locked state by the lid locking device is maintained. Therefore, in a washing process, even if the power supply is turned off to interrupt the operation action, the lid is locked until the rotation of the rotary drum stops and the third predetermined time has passed. As a result, even if the power supply is suddenly turned off, it is possible to prevent a dangerous state in which the lid is opened during the rotation of the rotary drum. Thus, it is possible to achieve a drum-type washing machine having safety and excellent reliability.

[0092] Note here that in this exemplary embodiment, an example in which the center of the rotation of rotary drum 1 is provided with rotation shaft 4 in the substantially inclining direction, and the direction of an axial center of rotary drum 1 is inclined downward toward the rear side from the front side is described, but the configuration is not necessarily limited to this configuration. For example, rotation shaft 4 is provided in substantially the horizontal direction (including the horizontal direction) of the rotation center of rotary drum 1, the direction of an axial center of rotary drum 1 may be provided in substantially the horizontal direction.

Claims

1. A drum-type washing machine comprising:

a rotary drum;

a water tank including the rotary drum;

a drum pulley securely installed on a rotation shaft of the rotary drum;

a motor fixed to an outer bottom portion of the water tank;

a belt that transmits rotation of the motor to the drum pulley;

a number-of-rotations detection unit for detecting a number of rotations of the motor;

a lid for opening/closing an opening part of the rotary drum;

a lid locking device for locking the lid in a closed state; and

a controller for executing each process of at least a washing process, a rinsing process, and a dehydrating process,

wherein the controller executes control by determining that the belt is broken or disengaged from the drum pulley according to any a stopping time and the number of rotations of the motor.

2. The drum-type washing machine of claim 1,
wherein the controller determines that the belt is either broken or disengaged from the drum pulley and executes control if the stopping time of the motor is shorter than a first predetermined time when the motor is braked.

3. The drum-type washing machine of claim 2,
wherein the controller extends the first predetermined time longer when the number of rotations of the motor is larger than a first predetermined number of rotations at the start of braking as opposed when the number of rotations of the motor is smaller than the first predetermined number of rotations.

4. The drum-type washing machine of claim 1,
wherein the controller determines that the belt is either broken or disengaged from the drum pulley and executes control when the number of rotations of the motor is larger than a second predetermined number of rotations.

5. The drum-type washing machine of claim 1,
wherein the controller determines that the belt is either broken or disengaged from the drum pulley and executes control if the controller detects the motor rotating at a larger number of rotations than a fourth predetermined number of rotations when the motor controls the rotary drum at a third predetermined number of rotations.

6. The drum-type washing machine of claim 5,
wherein the controller performs control by setting the fourth predetermined number of rotations of the motor to a larger number as the third predetermined number of rotations is increases beyond a predetermined range.

7. The drum-type washing machine of any one of claims 1 to 6,
wherein the controller controls the lid locking device to lock the lid until a second predetermined time has passed when the break is detected as being broken or disengaged, and then unlock the lid locking device after the second predetermined time has passed.

8. The drum-type washing machine of any one of claims 1 to 6,
wherein the controller maintains a setting of power-on is until a third predetermined time has passed when the break is detected as being broken or disengaged even when the controller is in a process of power-off, and turns off the power supply after the third predetermined time has passed.

Drawing