DETERMINING AN IMBALANCE WITHIN A WASH BASKET OF A WASHING MACHINE

Abstract

 The present invention refers to an arrangement to determine an imbalance (15) within a wash basket (2) of a washing machine (1). The washing machine (1) comprises a cabinet (3) enclosing a tub (4) which includes the wash basket (2) and two or more linking members (5) linking the tub (4) to the cabinet (3). The wash basket (2) is adapted to be in translational motion during rotation due to an unbalance in wash load. The arrangement comprises a suspension system (6) placed within the linking members (5) and adapted to generate a damping force to dampen translational motion of the wash basket (2), a sensor (7) adapted to measure the damping force in each of the suspension system (6), and adapted to generate a damping force data (8) based on the measured damping force for each of the suspension system (6), and a microcontroller (9) adapted to receive the damping force data (8) of each of the suspension system (6), and to process the damping force data (8) to determine the imbalance (15) within the wash basket (2).

Description

[0001] This invention refers to an arrangement within the washing machine according to claim 1, a washing machine according to claim 8, a method for providing an arrangement within the washing machine according to claim 10, and a method for determining an imbalance within a wash basket of a washing machine to claim 11.

Background of the Invention

[0002] Conventional washing machines include a cabinet which receives a stationary tub. The tub further includes a wash basket which contains wash load and rinse water for washing. A drive assembly and a brake assembly is positioned with respect to the tub and configured to rotate and control the rotation of the wash basket within the tub to cleanse the wash load placed into the wash basket. During, a wash or spin cycle, water is typically extracted from the wash load by rotating the wash basket containing the wash load at high rotational speeds. Centrifugal forces pull the majority of the water out of the wash load and through perforations in the rotating basket. A pump assembly can be used to rinse and drain the extracted water to a draining system.

[0003] The wash basket is typically supported by a suspension system designed to dampen translational motion induced by any imbalance within the rotating basket. High stresses are sometimes encountered within the wash basket, drive system, and suspension system during high-speed spin action used for water extraction during normal wash cycles and may create imbalance within the wash basket. During high-speed spin action, a force is generated which is proportional to the product of the mass of the wash load, the distance between the wash load and the center of rotation of the tub, and the square of the velocity of the tub. Small unbalances in the wash load can very easily generate large forces as a result of the high rotational velocities that may cause imbalance within the wash basket, and further causes excess vibration and noise which may cause damage to the washing machine

[0004] Known washing machines employs various sensing techniques to determine, if the machine is operating with an unbalanced load. One such technique includes current or load sensing in motor rotating control. When an unbalanced load is detected during an extraction spin cycle, the machine is stopped and a signal is generated to alert the user regarding the unbalanced load. Sensing techniques involving current or load sensing in the motor control can be inaccurate due to additional loads on the motor other than the load provided by any imbalance

Object of the Invention

[0005] It is therefore the object of the present invention is to provide a mechanism in a washing machine for determining an imbalance within a wash basket of the washing machine with accuracy.

Summary of the Invention

[0006] The before mentioned object is solved by an arrangement of the Claim 1.

[0007] The arrangement determines an imbalance within a wash basket of a washing machine, wherein the washing machine comprises a cabinet enclosing a tub which includes the wash basket and two or more linking members linking the tub to the cabinet. The wash basket is adapted to be in translational motion during rotation due to an unbalance in wash load. The arrangement includes a suspension system, a sensor and a microcontroller. The suspension system is placed within the linking members and generates a damping force to dampen translational motion of the wash basket. The sensor measures the damping force in each of the suspension system, and generates a damping force data based on the measured damping force for each of the suspension system. The microcontroller receives the damping force data of each of the suspension system, and processes the damping force data to determine an imbalance within the wash basket.

[0008] If the wash load has an unbalance, huge forces are generated during the rotation of the wash basket and which results in translational motion of the wash basket. The suspension system helps in dampening this translational motion. Due to this translational motion of the wash basket, damping force generated in each of the suspension system shall be different. Measurement of this damping force and further using this measurement for further processing results in more accurate determination of imbalance within the wash basket..

[0009] Further preferred embodiments are subject-matter of dependent claims and/or of the following specification parts.

[0010] According to a preferred embodiment of the invention, wherein the washing machine comprises four linking members. This embodiment provides is beneficial as it provides better balancing during the translational motion of the wash basket. Also, damping force data collected from four suspension system can provide more accurate estimation of imbalace within the wash basket.

[0011] According to a further embodiment of the arrangement, wherein at least one of the linking members connects to a base of the cabinet. This embodiment helps to provide a better balance and stability within the washing machine, with less possibility of breaking of the suspension system.

[0012] According to a further preferred embodiment of the arrangement, wherein the suspension system is of semi-active type, wherein this embodiment is beneficial, as it provides better stability with respect to passive suspension system. With respect to an active suspension system which requires an external energy source to function, the semi-active system uses external power only to adjust the damping levels and to power some components of the suspension system.

[0013] According to another embodiment of the arrangement, wherein the suspension system includes a piston, a foam covering the piston, and a case. The foam covering the piston is enclosed within the case, such that, the damping force is obtained as friction between the foam and the case. This embodiment provide an efficient way to provide a damping force and further provides an effective damping of translational motion of the wash basket, noise, and reduction of vibration within the washing machine.

[0014] According to a further embodiment of the arrangement, wherein the foam is saturated with magnetorheological fluid, and by applying a magnetic field to the foam, friction level between the foam and the case changes.

[0015] This embodiment is beneficial, as it allows an effective way to control and change damping characterstics of the suspension system continously based on load due to rotation of the wash load or due to translational motion of the wash basket.

[0016] According to another embodiment of the arrangement, wherein the microcontroller processes the damping force data received from each of the suspension system, and identifies a difference of force in each of the suspension system with respect to other suspension system of the washing machine. This embodiment is beneficial, as it provides an accurate way to determine imbalance within the wash basket.

[0017] The before mentioned object is also solved by a washing machine of Claim 8. The washing machine includes a cabinet comprising a tub, a wash basket placed within the tub, two or more linking members linking the tub to the cabinet, and an arrangement to identify an imbalance within the wash basket of the washing machine according to any of the claims 1 to 7. The wash basket receives a wash load and is adapted to rotate and to be in translational motion during rotation due to an unbalance in wash load.

[0018] According to a further preferred embodiment of the method, the washing machine comprises four linking members.

[0019] The before mentioned object is also solved by a method for providing an arrangement within a washing machine of Claim 10, which is used for determining an imbalance within a wash basket of a washing machine, wherein the washing machine comprises a cabinet enclosing a tub which includes a wash basket and two or more linking member adapted to link the tub to the cabinet. The wash basket is adapted to rotate and be in translational motion during rotation due to an unbalance in wash load. The method includes steps of:

• providing a suspension system within the linking members, wherein the suspension system is adapted to generate a damping force to dampen translational motion of the wash basket,
• providing a sensor which is adapted to measure the damping force in each of the suspension system, and adapted to generate a damping force data based on the measured damping force for each of the suspension mechanism,
• providing a microcontroller in communication coupling with the sensor for receiving the damping force data of each of the suspension system, and to process the damping force data to identify an imbalance within the wash basket.

[0020] The before mentioned object is also solved by a method of claim 11, wherein the method determines an imbalance within a wash basket of a washing machine. The wash basket is adapted to receive a wash load for washing the wash load. The washing machine comprises a cabinet enclosing a tub which includes the wash basket and two or more linking members linking the tub to the cabinet. The linking member comprises a suspension system. The method includes following steps:

• rotating the wash basket while washing the wash load;
• generating a translational motion during rotation due to an unbalance in wash load,
• generating a damping force to dampen translational motion of the wash basket by the suspension systems of each of the linking members, wherein the damping force in each of the suspension system can be same or different with respect to each other,
• measuring the damping force and generating a damping force data by a sensor,
• receiving the damping force data by a microcontroller from the sensor, processing the damping force data, and determining a imbalance within the wash basket.

[0021] According to a further preferred embodiment of the method, wherein processing the damping force data received from each of the suspension system, and identifying a difference of force in each of the suspension system with respect to other suspension system of the washing machine.

[0022] Further benefits, goals and features of the present invention will be described by the following specification of the attached figures, in which components of the invention are exemplarily illustrated. Components of the devices and method according to the inventions, which match at least essentially with respect to their function can be marked with the same reference sign, wherein such components do not have to be marked or described in all figures.

[0023] The invention is just exemplarily described with respect to the attached figure in the following.

Brief Description of the Drawings

[0024] 

Fig. 1 shows a washing machine according to one of the embodiment of the present invention.

Fig. 2 illustrates an arrangement placed within the washing machine to determine an imbalance within a wash basket of a washing machine.

Fig. 3 illustrates an exemplary suspension system used in one of the embodiment of the invention.

Detailed Description of the Drawings

[0025] Fig. 1 shows a washing machine 1 having a cabinet 3 enclosing a tub 4 which includes a wash basket 2, two linking members 5 which are linking the tub 4 to a base 10 of the cabinet 3, and an arrangement to determine an imbalance within the wash basket 2.

[0026] The wash basket 2 receives a wash load, and rotates to wash the wash load and rinse water. Due to rotation of the wash load, a wash load force is generated. The wash load force is proportional to the product of the mass of the wash load, the distance between the wash load and the center of rotation of the wash basket 2, and the square of the velocity of the wash basket 2. When the wash load is having an unbalance, it leads to differential wash load force on different section of the wash basket 2, which further results in translational motion of the wash basket 2, and hence an imbalance within the wash basket. This imbalance of the wash basket is required to be measured, so that an appropriate action can be taken to counter such imbalance.

[0027] To measure this imbalance, the washing machine is provided with an arrangement which includes a suspension system 6, a sensor and a microcontroller. The suspension system 6 is placed within the linking members 5 and generates a damping force to dampen the translational motion of the wash basket 2, when the wash basket 2 is rotating. The sensor measures the damping force in each of the suspension system 6, and generates a damping force data based on the measured damping force for each of the suspension system 6. The microcontroller receives the damping force data of each of the suspension system 6, processes the damping force data, and determines an imbalance within the wash basket 2.

[0028] In an alternate embodiment, the linking members 5 can connect to other walls of the cabinet 3, and not to the base 2. In yet another embodiment, one of the linking members 5 can connect to the base 10, and other linking members can connect to other walls of the cabinet 3.

[0029] In another embodiment, the washing machine 1 has four linking members 5, and accordingly has four suspensions systems, one within each linking members 5. The sensor measures damping force from each of the suspension system 6, and generates the damping force data for each of the suspension system 6. The microcontroller receives damping force data for each of the four suspension systems 6, and processes them to determine an imbalance within the wash basket 2.

[0030] The washing machine can have two or more linking members to implement the invention.

[0031] Fig. 2 illustrates an arrangement placed within the washing machine to determine an imbalance 15 within a wash basket of a washing machine.

[0032] The arrangement includes a suspension system 6 placed within the linking members, a sensor 7 placed in proximity to the suspension system 6, and a microcontroller 9. When there is an unbalance in the wash load, the wash basket is adapted to be in translational motion, when the wash basket is spinning. The suspension system 6 generates a damping force which dampens translational motion of the wash basket. In case of imbalance within the wash basket, this damping force shall be different in each of the suspension systems 6. The sensor 7 measures the damping force in each of the suspension system 6, and generates a damping force data 8 based on the measured damping force for each of the suspension system 6. The microcontroller 9 receives the damping force data 8 of each of the suspension system 6, and processes the damping force data 8 to determine the imbalance 15 within the wash basket.

[0033] In one of the embodiments, the microcontroller 9 processes the damping force data 8 received from each of the suspension system 6, and identifies a difference of damping force in each of the suspension system 6 with respect to other suspension system 6 of the washing machine. Based on such differences in the damping force, the microcontroller 9 determines the imbalance 15 within the wash basket.

[0034] Fig. 3 illustrates an exemplary suspension system 6 used in one of the embodiment of the invention, which is a semi-active type suspension system.

[0035] The suspension system 6 shown in the Fig 3. is Magnetorehological type suspension system filled with magnetorheological fluid 14, which is controlled by a magnetic field, usually using an electromagnet. This allows the damping characteristics of the suspension system 6 to be continuously controlled by varying the power of the electromagnet.

[0036] The suspension system 6 includes a piston 11, a foam 12 covering the piston, and a case 13. The foam 12 covering the piston 11 is enclosed within the case 13, such that, the damping force is obtained as friction between the foam 12 and the case 13. The foam 12 is saturated with magnetorheological fluid 14, and by applying a magnetic field to the foam 12, friction level between the foam 12 and the case 13 changes.

[0037] In an alternate embodiment, the arrangement can use other suspension types, which can be passive type or active type.

[0038] In yet another embodiment, the semi-active suspension type used in the arrangement can be electrorheological type which has electrorhelogical fluid. Damping characteristics of such suspension system varies in influence of electrical field.

[0039] Thus, the present invention refers to an arrangement within washing machine 1, which can effectively and accurately determine an imbalance within a wash basket 2, when the wash basket 2 spins at high speed. The imbalance is generally created due to an unbalance or overload of the wash load within the wash basket 2. The washing machine 1 comprises a cabinet 3 enclosing a tub 4 which includes the wash basket 2 and two or more linking members 5 linking the tub 4 to the cabinet 3, the wash basket 2 is adapted to be in translational motion during rotation due to an unbalance in wash load. The arrangement comprises a suspension system 6 placed within the linking members 5 and adapted to generate a damping force to dampen translational motion of the wash basket 2, a sensor 7 adapted to measure the damping force in each of the suspension system 6, and adapted to generate a damping force data 8 based on the measured damping force for each of the suspension system 6, and a microcontroller 9 adapted to receive the damping force data 8 of each of the suspension system 6, and to process the damping force data 8 to determine the imbalance 15 within the wash basket 2.

List of reference numbers

[0040] 

1

Washing Machine

2

wash basket

3

cabinet

4

tub

5

linking member

6

suspension system

7

sensor

8

damping force data

9

microcontroller

10

base

11

piston

12

foam

13

case

14

magnetorheological fluid

15

imbalance

Claims

1. An arrangement to determine an imbalance (15) within a wash basket (2) of a washing machine (1), wherein the washing machine (1) comprises a cabinet (3) enclosing a tub (4) which includes the wash basket (2) and two or more linking members (5) linking the tub (4) to the cabinet (3), the wash basket (2) is adapted to be in translational motion during rotation due to an unbalance in wash load, the arrangement comprises:

- a suspension system (6) placed within the linking members (5) and adapted to generate a damping force to dampen translational motion of the wash basket (2);

- a sensor (7) adapted to measure the damping force in each of the suspension system (6), and adapted to generate a damping force data (8) based on the measured damping force for each of the suspension system (6); and

- a microcontroller (9) adapted to receive the damping force data (8) of each of the suspension system (6), and to process the damping force data (8) to determine the imbalance (15) within the wash basket (2).

2. The arrangement according to claim 1, wherein the washing machine comprises four linking members (5).

3. The arrangement according to any of the claims 1 or 2, wherein at least one of the linking members (5) connects to a base (10) of the cabinet (3).

4. The arrangement according to any of the claims 1 to 3, wherein the suspension system (6) is of semi-active type.

5. The arrangement according to any of the claims 1 to 4, wherein the suspension system (6) comprises a piston (11), a foam (12) covering the piston (11), and a case (13), the foam (12) covering the piston (11) is enclosed within the case (13), such that, the damping force is obtained as friction between the foam (12) and the case (13).

6. The arrangement according to claim 5, wherein the foam (12) is saturated with magnetorheological fluid (14), and by applying a magnetic field to the foam (12), friction level between the foam (12) and the case (13) changes.

7. The arrangement according to any of the claims 1 to 6, wherein the microcontroller (9) processes the damping force data (8) received from each of the suspension system (6), and identifies a difference of force in each of the suspension system (6) with respect to other suspension system (6) of the washing machine.

8. A washing machine (1) comprising:

- a cabinet (3) comprising a tub (4);

- a wash basket (2) placed within the tub (4) and adapted to receive a wash load, the wash basket (2) is adapted to rotate and to be in translational motion during rotation due to an unbalance in wash load;

- two or more linking members (5) linking the tub (4) to the cabinet (3); and

- an arrangement to identify an imbalance (15) within the wash basket (2) of the washing machine (1) according to any of the claims 1 to 7.

9. The washing machine (1) according to claim 8, wherein the washing machine (1) comprises four linking members (5).

10. A method for providing an arrangement within a washing machine (1), the arrangement determines an imbalance (15) within a wash basket (2) of the washing machine (1), wherein the washing (1) machine comprises a cabinet (3) enclosing a tub (4) which includes the wash basket (2) and two or more linking members (5) linking the tub (4) to the cabinet (3), the wash basket (2) is adapted to rotate and be in translational motion during rotation due to an unbalance in wash load, the method comprises:

- providing a suspension system (6) within the linking members (5), wherein the suspension system (6) is adapted to generate a damping force to dampen translational motion of the wash basket (2);

- providing a sensor (7) which is adapted to measure the damping force in each of the suspension system, and adapted to generate a damping force data (8) based on the measured damping force for each of the suspension system (6); and

- providing a microcontroller (9) in communication coupling with the sensor (7) for receiving the damping force data (8) of each of the suspension system (6), and to process the damping force data (8) to identify the imbalance (15) within the wash basket (2).

11. A method for determining an imbalance (15) within a wash basket (2) of a washing machine (1), wherein the wash basket (2) is adapted to receive a wash load for washing the wash load, wherein the washing machine (1) comprises a cabinet (3) enclosing a tub (4) which includes the wash basket (2) and two or more linking members (5) linking the tub (4) to the cabinet (3), the linking member (5) comprises a suspension system (6), the method comprising:

- rotating the wash basket (2) while washing the wash load;

- generating a translational motion of the wash basket (2) during rotation due to an unbalance in wash load;

- generating a damping force to dampen translational motion of the wash basket (2) by the suspension systems (6) of each of the linking members (5), wherein the damping force in each of the suspension system (6) can be same or different with respect to each other;

- measuring the damping force and generating a damping force data (8) by a sensor (7); and

- receiving the damping force data (8) by a microcontroller (9) from the sensor (7), processing the damping force data (8), and determining the imbalance (15) within the wash basket (2).

12. The method according to claim 11, wherein processing the damping force data (8) received from each of the suspension system (6), and identifying a difference of force in each of the suspension system (6) with respect to other suspension system (6) of the washing machine (1).

Drawing