Washing machine

Abstract

To provide a washing machine capable of more adequately controlling rotation.SOLUTION: A washing machine according to the embodiment has a water tub, a rotary tub, a motor, an acceleration sensor, a control part, a first determination part, and a second determination part. The acceleration sensor is provided with respect to the water tub. The control part controls the motor and executes a dewatering process by rotating the rotary tub. During a first period included in the dewatering process, the first determination part repeatedly executes a first determination related to stop of the rotary tub based on amount of change of a detection value obtained from a detection result of the acceleration sensor and suppresses execution of the first determination during a second period that is included in the dewatering process and set before the first period. The second determination part repeatedly executes a second determination related to stop of the rotary tub based on the magnitude of the acceleration obtained from the detection result of the acceleration sensor at least during the second period.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] An embodiment of the present invention relates to a washing machine. [Background technology]

[0002] A washing machine is known which sequentially samples and detects detection values ​​from a vibration detection means while spinning the spin tub, calculates the difference between the sampled detection value and the previous sampled detection value for each sample, and slows down the rotation of the spin tub when the number of times that this difference exceeds a set value reaches or exceeds a set number. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5784532 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a washing machine capable of performing more appropriate spin control. [Means for solving the problem]

[0005] A washing machine according to an embodiment includes a water tub, a spin tub, a motor, an acceleration sensor, a control unit, a first determination unit, and a second determination unit. The spin tub is disposed in the water tub and stores clothes. The motor drives the spin tub to rotate. The acceleration sensor is provided in association with the water tub. The control unit controls the motor to execute a spin-drying process to spin the spin tub. The first determination unit repeatedly performs a first determination regarding the stop of the spin tub based on a change in a detection value obtained from a detection result of the acceleration sensor during a first period included in the spin-drying process, and suppresses the first determination during a second period included in the spin-drying process and set before the first period. The second determination unit repeatedly performs a second determination regarding the stop of the spin tub based on a magnitude of acceleration obtained from a detection result of the acceleration sensor during at least the second period. [Brief description of the drawings]

[0006] [Figure 1] 1 is a cross-sectional view showing a part of the inside of the washing machine according to a first embodiment. [Diagram 2] 2 is a cross-sectional view taken along line F2-F2 of the washing machine shown in FIG. 1. [Diagram 3] FIG. 2 is a block diagram showing functional units related to the control device according to the first embodiment. [Figure 4] 5A to 5C are diagrams for explaining a determination process in a dehydration step in the first embodiment. [Diagram 5] 5A to 5C are diagrams for explaining the action of determination using a change amount determination unit according to the first embodiment. [Figure 6] 5 is a diagram for explaining a determination suppression period of the change amount determination unit according to the first embodiment. [Figure 7] 5 is a flowchart showing a control flow relating to a change amount determination unit and an acceleration determination unit in the first embodiment. [Figure 8] FIG. 11 is a diagram showing threshold information according to a first modified example. [Figure 9] FIG. 11 is a diagram showing threshold information according to a second modified example. [Figure 10] FIG. 13 is a diagram showing threshold value information according to a third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, the washing machine of the embodiment will be described with reference to the drawings. In the following description, the same reference numerals are given to components having the same or similar functions. And, duplicated descriptions of those components may be omitted. In this application, "based on XX" means "based on at least XX" and may include the case of being based on another element in addition to XX. Also, "based on XX" is not limited to the case of using XX directly, but may also include the case of being based on XX that has been calculated or processed. In this application, "XX or YY" is not limited to either one of XX and YY, but may include both XX and YY. This also applies to the case where there are three or more selective elements. XX and YY are any element (for example, any information).

[0008] In this application, "obtain" is not limited to actively obtaining information by transmitting a transmission request, but may also include passively receiving information transmitted from another device. Furthermore, "obtain" is not limited to directly obtaining target information (information to be obtained) from outside, but may also include generating and obtaining target information by performing calculations or processing on information obtained from outside. In this application, "parallel" may also include "approximately parallel."

[0009] (First embodiment) First, a washing machine 1 of the first embodiment will be described. In this embodiment, the washing machine 1 will be described as a vertical washing machine. In this application, a "vertical washing machine" is a washing machine in which the rotation center axis of the rotating tub is arranged parallel to the vertical direction. However, the washing machine 1 may be a drum washing machine in which the rotation center axis of the rotating tub (drum) is arranged diagonally to the vertical direction, or a two-tub washing machine in which the washing tub and the spin tub are separate. Also, the "washing machine" in this application may be a washing and drying machine with a drying function.

[0010] <1. Overall configuration of the washing machine> 1 is a cross-sectional view showing a part of the inside of a washing machine 1. The washing machine 1 includes an outer case 11, a water tub 12, a spin tub 13, a drive unit 14, and a support structure 15, for example.

[0011] <1.1 Outer box> The outer box 11 is a housing that forms the outer shell of the washing machine 1. The outer box 11 has, for example, a rectangular parallelepiped shape. The outer box 11 houses a water tub 12, a spin tub 13, a drive unit 14, and a support structure unit 15.

[0012] <1.2 Aquarium> Water tub 12 is a tank body capable of storing water during a washing process or a rinsing process. Water tub 12 is a bottomed cylindrical shape that extends vertically. A central axis CL1 of water tub 12 is arranged parallel to the vertical direction. Water tub 12 has, for example, a bottom 21 and a peripheral wall 22 that extends cylindrically upward from a peripheral end of bottom 21. Bottom 21 is provided with drainage section 21a. Water supplied into water tub 12 is discharged to the outside of washing machine 1 via drainage section 21a.

[0013] A water tub cover 23 is attached to the upper end of water tub 12. Water tub cover 23 has inner lid 23a, water supply port 23b (see FIG. 2), and air outlet 23c (see FIG. 2). Inner lid 23a closes the upper end of water tub 12 in an openable and closable manner. Water supply port 23b is an opening through which water is supplied from a water supply unit (not shown) into water tub 12 (inside rotating tub 13). Air outlet 23c is an opening through which hot air is supplied from an air outlet (not shown) into water tub 12 (inside rotating tub 13).

[0014] <1.3 Rotating tank> Rotary tub 13 is a tub body disposed within water tub 12 to house clothes. Hereinafter, the clothes housed in rotary tub 13 may be referred to as "laundry." Rotary tub 13 has a rotation center axis CL2 disposed parallel to the vertical direction. Rotary tub 13 is a cylindrical shape with a bottom that is aligned along the vertical direction. Rotary tub 13 has, for example, a bottom 31, a peripheral wall 32, and a rotation balancer 33.

[0015] The bottom 31 is bowl-shaped and made of, for example, synthetic resin. The peripheral wall 32 extends cylindrically upward from the peripheral end of the bottom 31. The peripheral wall 32 is formed of, for example, a stainless steel plate. The peripheral wall 32 has a plurality of holes 32a penetrating the peripheral wall 32 in the radial direction of the spin tub 13. Note that FIG. 1 illustrates only a portion of the plurality of holes 32a. When dehydrating the laundry, the water separated from the laundry is discharged to the outside of the spin tub 13 through the plurality of holes 32a. When drying the laundry, the hot air supplied into the spin tub 13 is discharged to the outside of the spin tub 13 through the plurality of holes 32a. The rotation balancer 33 is attached to the upper end of the peripheral wall 32.

[0016] <1.4 Drive unit> Driving unit 14 is a device that drives spin tub 13. Driving unit 14 includes, for example, a motor 41 provided below water tub 12 and an agitating member (pulsator) 42 provided on bottom 31 of spin tub 13. Driving unit 14 is capable of switching the connection state of motor 41 to spin tub 13, and is also capable of switching the connection state of motor 41 to agitating member 42. In the washing stroke and rinsing stroke, driving unit 14 stops the rotation of spin tub 13 while driving motor 41 to rotate agitating member 42 alternately in the forward direction and the reverse direction. On the other hand, driving unit 14 drives spin tub 13 and agitating member 42 to rotate together in one direction in the dehydration stroke.

[0017] <1.5 Support structure> The support structure 15 is a structure that supports the water tank 12 inside the outer box 11. The support structure 15 includes, for example, a lid-side support part 51 (see FIG. 2), a hanging rod 52, a bottom-side support part 53, and an elastic member 54. The lid-side support part 51 is disposed at each corner of the rectangular parallelepiped outer box 11, and supports the water tank 12 via the water tank cover 23. The hanging rod 52 extends downward from the lid-side support part 51. The bottom-side support part 53 is disposed at each corner of the rectangular parallelepiped outer box 11, and is connected to the bottom 21 of the water tank 12. One end of the elastic member 54 is connected to the lower end of the hanging rod 52. The other end of the elastic member 54 is connected to the bottom-side support part 53, and supports the bottom 21 of the water tank 12 via the bottom-side support part 53. The elastic member 54 is a coil spring or the like, and is elastically deformable. According to the configuration of the support structure 15 described above, the water tub 12 is elastically supported by the outer box 11 while being suspended from the outer box 11 by the support structure 15. The above-described structure is one example of the support structure 15. Instead of the above example, the support structure 15 may have a structure that supports the water tub 12 from below.

[0018] <1.6 Acceleration sensor> Next, the acceleration sensor 60 will be described. As shown in Fig. 1, washing machine 1 has acceleration sensor 60. Acceleration sensor 60 is provided in relation to water tub 12 and detects acceleration. In this application, "provided in relation to water tub" means provided so as to be able to directly or indirectly detect acceleration acting on water tub 12. In this application, "provided in relation to water tub" is not limited to being directly attached to water tub 12, but may also include being attached to support structure 15 or being attached to water tub 12 via another member.

[0019] In this embodiment, the acceleration sensor 60 is attached to the outer surface of the water tank 12. The acceleration sensor 60 is attached, for example, to the upper end of the water tank 12. For example, the acceleration sensor 60 is provided at the rear end of the water tank 12. The acceleration sensor 60 is capable of detecting acceleration acting in the axial direction D1 of the water tank 12. The axial direction D1 of the water tank 12 is parallel to the central axis CL1 of the water tank 12 and is parallel to the vertical direction.

[0020] 2 is a cross-sectional view of washing machine 1 taken along line F2-F2 in FIG. 1. In this embodiment, acceleration sensor 60 is capable of detecting acceleration acting in radial direction D2 of water tub 12. Acceleration sensor 60 may be capable of detecting acceleration acting in circumferential direction D3 of water tub 12 instead of / in addition to acceleration acting in radial direction D2 of water tub 12. In this application, the term "circumferential direction" is not strictly limited to a direction along the outer circumferential surface of water tub 12, but is used in a broader sense that may include a tangential direction to the outer circumferential surface of water tub 12.

[0021] In this embodiment, the acceleration sensor 60 is an analog acceleration sensor. However, the acceleration sensor 60 may be a digital acceleration sensor. The detection result of the acceleration sensor 60 is transmitted to the control device 100.

[0022] <1.7 Temperature sensor> Next, the temperature sensor 70 will be described. 2, the washing machine 1 has a temperature sensor 70. The temperature sensor 70 is provided, for example, in the outer box 11, and is capable of detecting the environmental temperature outside the washing machine 1 (for example, the room temperature of the room in which the washing machine 1 is placed). The detection result of the temperature sensor 70 is transmitted to the control device 100.

[0023] <1.8 Control device> Next, the control device 100 will be described. The washing machine 1 has a control device 100 (see FIG. 1). The control device 100 is mainly configured with a computer including, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an EEPROM (Electrically Erasable Programmable ROM), and the like.

[0024] <2. Control device> Next, the functional units related to the control device 100 will be described. FIG. 3 is a block diagram showing functional units related to the control device 100. The control device 100 has, for example, a weight detection unit 110, a fabric type detection unit 120, a rotation speed detection unit 130, a control unit 140, a spin-drying operation determination unit 150, and a storage unit 190. The weight detection unit 110, the fabric type detection unit 120, the rotation speed detection unit 130, the control unit 140, and the spin-drying operation determination unit 150 are all or partly realized by a hardware processor such as a CPU executing a program (software). However, all or part of these functional units may be realized by hardware (including circuitry) such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), or a discrete circuit, or may be realized by cooperation between software and hardware. The storage unit 190 is, for example, realized by one or a combination of a RAM, a ROM, and an EEPROM.

[0025] <2.1 Weight detection section> Weight detection unit 110 detects the weight of the laundry contained in spin tub 13. Here, the load of motor 41 that drives agitation member 42 changes according to the weight of the laundry contained in spin tub 13. For example, the heavier the laundry contained in spin tub 13, the heavier the load of motor 41 that drives agitation member 42. Weight detection unit 110 acquires load value information indicating the load acting on motor 41 when agitation member 42 is rotated in the forward and reverse directions before water is poured into water tub 12 and laundry is contained in spin tub 13. The load value information is, for example, a current value supplied to motor 41 or a voltage value applied to motor 41. Then, weight detection unit 110 detects the weight of the laundry contained in spin tub 13 based on the acquired load value information and a threshold value for weight detection included in threshold information 191.

[0026] <2.2 Fabric quality detection unit> The fabric type detection unit 120 detects the fabric type of the laundry stored in the spin tub 13. "Detecting the fabric type" means, for example, judging whether the laundry is mainly cotton-based or mainly synthetic fiber-based. Here, the load on the motor 41 that rotates the spin tub 13 changes depending on the difference in water absorbency due to the fabric type of the laundry. The fabric type detection unit 120 acquires, for example, the load value information detected before the start of pouring water into the water tub 12 and the load value information indicating the load acting on the motor 41 detected when the spin tub 13 is rotated after the water pouring into the water tub 12 is completed. Then, the fabric type detection unit 120 detects the fabric type of the laundry stored in the spin tub 13 based on the relationship between the load value information acquired before the start of pouring water into the water tub 12 and the load value information acquired after the water pouring into the water tub 12 is completed.

[0027] <2.3 Rotational speed detection section> The rotation speed detection unit 130 detects the rotation speed (e.g., the number of rotations per unit time) of the motor 41. The rotation speed detection unit 130 acquires rotation speed information indicating the number of rotations of the motor 41 from the motor 41. The rotation speed information is, for example, information acquired by a rotation speed sensor such as a rotary encoder provided on the motor 41. The rotation speed detection unit 130 detects the rotation speed of the motor 41 based on the acquired rotation speed information. Note that, instead of the above example, the rotation speed information may be a current value supplied to the motor 41 or a voltage value applied to the motor 41. In the following description, "rotation speed" means the number of rotations [rpm] per unit time.

[0028] <2.4 Control section> The control unit 140 performs overall control of the entire washing machine 1. For example, the control unit 140 controls the drive unit 14 (e.g., the motor 41) to execute a washing operation including a washing step, a rinsing step, and a spin-drying step, and a subsequent drying operation (drying step). In this embodiment, the control unit 140 determines the contents of the washing operation and the drying operation (such as the amount of water poured and the operation time) based on the weight of the laundry detected by the weight detection unit 110 and the fabric quality of the laundry detected by the fabric quality detection unit 120.

[0029] In this embodiment, when spin-drying operation determination unit 150 (described later) determines that an inappropriate state for the rotation of spin tub 13 has occurred, control unit 140 stops spin tub 13. In this case, control unit 140 executes the spin-drying process again. "Restarting the spin-drying process" means, for example, performing the spin-drying process again after rotating spin tub 13 without pouring water into water tub 12 to loosen the laundry, or performing the spin-drying process again after pouring water into water tub 12 to remove the laundry stuck to the inner surface of spin tub 13.

[0030] <2.5 Dehydration operation determination section> The spin-drying operation determination unit 150 determines whether or not an inappropriate state for the rotation of the spin tub 13 has occurred. An "inappropriate state for rotation" is, for example, an imbalance in the spin tub 13 that is equal to or greater than a predetermined standard, or abnormal vibration in the spin tub 13. "Imbalance" refers to an unbalanced load state caused by uneven distribution of laundry in the spin tub 13.

[0031] <3. Determination process by dehydration operation determination unit> Next, a description will be given of the determination process performed by dehydration operation determiner 150. Dehydration operation determiner 150 includes an imbalance determiner 151, a change amount determiner 152, and an acceleration determiner 153, for example.

[0032] 4 is a diagram for explaining the determination process in the spin-drying step. First, the transition of the rotation speed of spin tub 13 in the spin-drying step will be explained. The spin-drying step includes operation times T1, T2, and T3.

[0033] (Operating time T1) The operation time T1 is a time during which the rotation speed of the rotating tub 13 is increased stepwise to the number of rotations R3 while checking for the presence or absence of imbalance in the rotating tub 13.

[0034] (Operating time T2) Operation time T2 is a period set after operation time T1. Operation time T2 is a time during which the rotation speed of spin tub 13 is gradually increased. Operation time T2 is a time during which the rotation speed of spin tub 13 is gradually increased, for example, to rotation speed R4, which is the maximum rotation speed in the ongoing dehydration process. During operation time T2, the rotation speed of spin tub 13 is gradually increased over time, for example, by a constant increment. Operation time T2 is an example of an "accelerated operation time."

[0035] (Operating time T3) Operation time T3 is a time set after operation time T2. Operation time T3 includes, for example, the time immediately after the rotation speed of the rotating tub 13 reaches rotation number R4. Operation time T3 is a time during which the rotation speed of the rotating tub 13 is kept constant after operation time T2. For example, during operation time T3, the rotation speed of the rotating tub 13 is maintained at the maximum rotation speed, that is, rotation number R4. Operation time T3 is an example of a "constant speed operation time."

[0036] More specifically, the operation time T3 includes an initial period T3A and a subsequent period T3B. The subsequent period T3B is a period including the latter half of the operation time T3. The subsequent period T3B is, for example, longer than the initial period T3A. The subsequent period T3B is an example of a "first period". On the other hand, the initial period T3A is a period set before the subsequent period T3B. For example, the initial period T3A is a period set between the operation time T2 and the subsequent period T3B. The initial period T3A includes, for example, the time immediately after the rotation speed of the rotating tub 13 reaches the maximum rotation speed, the number of rotations R4. The initial period T3A is an example of a "second period".

[0037] <3.1 Unbalance judgment section> The imbalance determination unit 151 determines whether or not there is an imbalance in the spin tub 13 that is equal to or greater than a predetermined standard, based on the detection result of the acceleration sensor 60. The imbalance determination unit 151 performs determinations J1 to J5 described below as determinations related to the stopping of the spin tub 13 (for example, determination as to whether or not the spin tub 13 needs to be stopped).

[0038] (Judgment J1) Decision J1 is made during the period from the start of the spin-drying process until the rotation speed of spin tub 13 reaches rotation speed R1. Decision J1 is made based on a detection value (e.g., the output value of acceleration sensor 60 itself) obtained from the detection result of acceleration sensor 60. Decision J1 uses, for example, the detection value detected regarding the acceleration acting in radial direction D2 (or circumferential direction D3) of water tub 12.

[0039] For example, the imbalance determination unit 151 compares the detection value with a threshold value for determination J1 included in the threshold value information 191. If the detection value is equal to or greater than the threshold value, the imbalance determination unit 151 determines that it is necessary to stop the spin tub 13 (restart the spin-drying process). On the other hand, if the detection value is less than the threshold value, the imbalance determination unit 151 determines that it is not necessary to stop the spin tub 13.

[0040] (Judgment J2~J4) The determinations J2 to J4 are performed in a period after the rotation speed of spin tub 13 is increased stepwise to the rotation speeds R1, R2, and R3 in the dehydration process. The determinations J2 to J4 are performed based on a detection value obtained from the detection result of acceleration sensor 60 (for example, a detection value obtained by performing a predetermined calculation on the output value of acceleration sensor 60). In this embodiment, imbalance determination unit 151 performs a calculation to reduce the influence of the rotation speed of spin tub 13 on the output value of acceleration sensor 60 based on the detection result of rotation speed detection unit 130 as the predetermined calculation, and calculates a detection value (hereinafter, for convenience of explanation, referred to as a "vibration amount detection value") that can evaluate the vibration amount of water tub 12. The vibration amount detection value is an example of a "detection value obtained from the detection result of the acceleration sensor". The determinations J2 to J4 use, for example, the detection value detected regarding the acceleration acting in the radial direction D2 (or circumferential direction D3) of water tub 12.

[0041] In this embodiment, the imbalance determination unit 151 compares the vibration amount detection value with each of the thresholds for determinations J1 to J4 included in the threshold information 191. When the vibration amount detection value is equal to or greater than the threshold, the imbalance determination unit 151 determines that it is necessary to stop the spin tub 13 (restart the spin-drying process). On the other hand, when the detection value is less than the threshold, the imbalance determination unit 151 determines that it is not necessary to stop the spin tub 13. Note that in determinations J2 to J4, the output value of the acceleration sensor 60 itself may be used as the detection value obtained from the detection result of the acceleration sensor instead of the vibration amount detection value.

[0042] (Judgment J5) The judgment J5 is a judgment for determining the maximum rotation speed (number of rotations R4) in the dehydration process being performed. For example, the judgment J5 is a judgment for selecting the maximum rotation speed in the dehydration process being performed from a plurality of maximum rotation speed candidates set in advance. The judgment J5 is performed, for example, during a period in which the rotation speed of the spin tub 13 is increasing from the rotation speed R3. The judgment J5 is performed based on a detection value (for example, the above-mentioned vibration amount detection value) obtained from the detection result of the acceleration sensor 60, similar to the judgments J2 to J4. That is, in this embodiment, the unbalance judgment unit 151 performs the judgment J5 based on a detection value obtained by performing a calculation for reducing the influence of the rotation speed of the spin tub 13 on the output value of the acceleration sensor 60 based on the detection result of the rotation speed detection unit 130. The judgment J5 uses, for example, the above-mentioned detection value detected regarding the acceleration acting in the radial direction D2 (or circumferential direction D3) of the water tub 12.

[0043] For example, the unbalance determination unit 151 compares the vibration amount detection value with a threshold for determination J5 included in the threshold information 191. When the vibration amount detection value is less than the threshold, the unbalance determination unit 151 sets the maximum rotation speed (rotation speed R4) of the spin tub 13 to a first rotation speed. On the other hand, when the vibration amount detection value is equal to or greater than the threshold, the unbalance determination unit 151 sets the maximum rotation speed (rotation speed R4) of the spin tub 13 to a second rotation speed lower than the first rotation speed. Note that in determination J5, the output value of the acceleration sensor 60 itself may be used as the detection value obtained from the detection result of the acceleration sensor instead of the vibration amount detection value.

[0044] <3.2 Change amount determination unit> The change amount determination unit 152 determines whether or not abnormal vibration is present in the spin tub 13 based on the detection result of the acceleration sensor 60. The change amount determination unit 152 performs determinations K1 and K2 described below as a determination regarding the stop of the spin tub 13 (for example, a determination regarding the need to stop the spin tub 13). The change amount determination unit 152 is an example of a "first determination unit."

[0045] (Decision K1) Judgment K1 is performed, for example, during a part of operation time T1 and during the entire operation time T2. In judgment K1, change amount judgment unit 152 performs judgment based on the amount of change in a detection value (for example, the output value of acceleration sensor 60 itself) obtained from the detection result of acceleration sensor 60. Note that the detection value used in judgment K1 may be the vibration amount detection value described above instead of the output value itself. In judgment K1, for example, the detection value detected regarding the acceleration acting in radial direction D2 (or circumferential direction D3) of water tank 12 is used. Radial direction D2 or circumferential direction D3 is an example of the "first direction".

[0046] In this embodiment, the change amount determination unit 152 sequentially acquires the detection values ​​at a predetermined time interval. For example, the change amount determination unit 152 sequentially acquires the detection values ​​by sampling and acquiring the detection values ​​at a predetermined time interval (e.g., 1 second interval) from among the detection results of the acceleration sensor 60 acquired at a 0.1 second cycle. Then, the change amount determination unit 152 performs a judgment K1 as the amount of change in the detection values ​​acquired at the predetermined time interval based on the magnitude of the difference between the previously acquired detection value and the most recently acquired detection value.

[0047] For example, the change amount determination unit 152 compares the magnitude of the change (e.g., the magnitude of the difference) with a threshold for determination K1 included in the threshold information 191. If the magnitude of the change is equal to or greater than the threshold, the change amount determination unit 152 determines that it is necessary to stop the spin tub 13 (restart the spin-drying process). On the other hand, if the magnitude of the change is less than the threshold, the change amount determination unit 152 determines that it is not necessary to stop the spin tub 13. Determination K1 is repeatedly performed at the predetermined time intervals (e.g., one second intervals) throughout the entire subsequent period T3B.

[0048] (Judgment K2) Judgment K2 is performed in a subsequent period T3B included in operation time T3. In judgment K2, change amount judgment unit 152 performs judgment K2 based on the amount of change in a detection value (e.g., the output value of acceleration sensor 60 itself) obtained from the detection result of acceleration sensor 60, similar to judgment K1. Note that the detection value used in judgment K2 may be the vibration amount detection value described above instead of the output value itself. In judgment K2, for example, the detection value detected regarding the acceleration acting in radial direction D2 (or circumferential direction D3) of water tub 12 is used.

[0049] In this embodiment, the change amount determination unit 152 sequentially acquires the detection values ​​at a predetermined time interval, similar to the judgment K1. For example, the change amount determination unit 152 sequentially acquires the detection values ​​by sampling and acquiring the detection values ​​at a predetermined time interval (e.g., 1 second interval) from among the detection results of the acceleration sensor 60 acquired at 0.1 second intervals. Then, the change amount determination unit 152 performs judgment K2 based on the magnitude of the difference between the previously acquired detection value and the most recently acquired detection value as the amount of change in the detection values ​​acquired at the predetermined time interval.

[0050] For example, the change amount determination unit 152 compares the magnitude of the change (e.g., the magnitude of the difference) with a threshold for determination K2 included in the threshold information 191. If the magnitude of the change is equal to or greater than the threshold, the change amount determination unit 152 determines that it is necessary to stop the spin tub 13 (restart the spin-drying process). On the other hand, if the magnitude of the change is less than the threshold, the change amount determination unit 152 determines that it is not necessary to stop the spin tub 13. Determination K2 is repeated at the predetermined time intervals (e.g., 1 second intervals) throughout the entire subsequent period T3B. Determination K2 is an example of a "first determination."

[0051] Fig. 5 is a diagram for explaining the function of determination using change amount determination unit 152. Fig. 5 shows a waveform curve X of the detected value of acceleration sensor 60 when abnormal vibrations Xa, Xb occur in water tub 12. For example, when an imbalance greater than expected occurs due to the movement of clothes in spin tub 13 during the spin cycle or when water that could not be discharged due to waterproof clothes is discharged all at once, this can cause such abnormal vibration.

[0052] Here, by providing the above-mentioned judgments K1 and K2 and monitoring the magnitude of the above-mentioned change amount (for example, the magnitude of the difference), the following effects can be expected compared to the case of simply monitoring the magnitude of the acceleration. That is, by providing the above-mentioned judgments K1 and K2 and monitoring the magnitude of the above-mentioned change amount (for example, the magnitude of the difference), if an imbalance state that may cause abnormal vibration occurs, the occurrence of abnormal vibration can be accurately detected at an early stage of the abnormal vibration (for example, before the abnormal vibration becomes large). As a result, by stopping the rotation of spin tub 13 in response to the detection of abnormal vibration, the occurrence of large abnormal vibration in water tub 12 can be more appropriately suppressed.

[0053] (Determination suppression period of the change amount determination unit) FIG. 6 is a diagram for explaining the determination suppression period of the change amount determination unit 152. FIG. 6 shows an enlarged view of the area surrounded by the line F6 shown in FIG. 4. In this embodiment, when the rotation speed of the spin tub 13 is increased toward the rotation speed R4 during the operation time T2, an upper overshoot Ya occurs in which the rotation speed of the spin tub 13 temporarily increases beyond the rotation speed R4. The overshoot means a temporary excess of the rotation speed relative to the target rotation speed. In addition, as a result of adjusting the rotation speed of the spin tub 13 according to this upper overshoot Ya, a lower overshoot Yb occurs in which the rotation speed of the spin tub 13 temporarily decreases beyond the rotation speed R4. The initial period T3A described above is a period in which the rotation speed of the spin tub 13 converges within a predetermined threshold range while including such overshoots Ya and Yb. The length of the initial period T3A is, for example, 10 seconds. On the other hand, the subsequent period T3B described above is a period in which the overshoots Ya and Yb settle down and the fluctuation in the rotation speed of the spin tub 13 falls within the above threshold range centered on the rotation speed R4.

[0054] Here, if the above-mentioned judgments K1 and K2 are performed in such an initial period T3A, there is a possibility that the overshoots Ya and Yb will be erroneously detected as abnormal vibration. For this reason, in this embodiment, the change amount judgment unit 152 sets the initial period T3A as a judgment suppression period, and suppresses making the judgments K1 and K2 in the initial period T3A (for example, stops making the judgments K1 and K2). Note that "suppressing the judgment" may also mean reducing the frequency of making the judgment instead of stopping the judgment.

[0055] <3.3 Acceleration judgment section> The acceleration determination unit 153 determines whether or not abnormal vibration is present in the spin tub 13 based on the detection result of the acceleration sensor 60. The acceleration determination unit 153 performs a determination S described below as a determination regarding the stop of the spin tub 13 (e.g., a determination regarding the need to stop the spin tub 13). The acceleration determination unit 153 is an example of a "second determination unit."

[0056] (Judgment S) The judgment S is performed at least in the initial period T3A. In this embodiment, the judgment S is performed for the entire period of the operation time T3. In the judgment S, the acceleration judgment unit 153 performs the judgment based on the acceleration obtained from the detection result of the acceleration sensor 60 (for example, the output value of the acceleration sensor 60 itself). In this embodiment, the acceleration judgment unit 153 uses a detection value that reflects the rotation speed of the spin tub 13 compared to the vibration amount detection value as the acceleration obtained from the detection result of the acceleration sensor 60 and used in the judgment S. For example, the acceleration used in the judgment S is a detection value whose base value becomes larger as the rotation speed of the spin tub 13 becomes higher. For example, the acceleration used in the judgment S is a detection value that can evaluate the magnitude of the impact acting on the water tub 12.

[0057] For ease of explanation, the acceleration used in the determination S may be referred to as a "detected value" below. Note that the "acceleration" in this application is not limited to the acceleration detected by the acceleration sensor 60, but may be a calculated value obtained by performing a predetermined calculation on the detected acceleration. For example, the acceleration used in the determination S may be the vibration amount detection value described above instead of the output value of the acceleration sensor 60 itself.

[0058] For example, in the judgment S, at least a detection value of acceleration detected regarding the acceleration acting in the axial direction D1 of the water tank 12 is used. The axial direction D1 is an example of a "second direction." In this embodiment, in the judgment S, a judgment S1 based on the detection value detected regarding the acceleration acting in the axial direction D1 of the water tank 12 and a judgment S2 based on the detection value detected regarding the acceleration acting in the radial direction D2 (or circumferential direction D3) of the water tank 12 are made.

[0059] In this embodiment, the acceleration determination unit 153 performs the determination S based on the magnitude of the detection value (the magnitude of the acceleration) obtained from the detection result of the acceleration sensor. For example, the acceleration determination unit 153 compares the magnitude of the detection value in the axial direction D1 with a threshold value for determination S1 (upper limit acceleration in the axial direction D1) included in the threshold information 191, and compares the magnitude of the detection value in the radial direction D2 (or the circumferential direction D3) with a threshold value for determination S2 (upper limit acceleration in the radial direction D2 or the circumferential direction D3) included in the threshold information 191. If the magnitude of the detection value is equal to or greater than the threshold value in at least one of the determinations S1 and S2, the acceleration determination unit 153 determines that it is necessary to stop the spin tub 13 (restart the spin-drying process). On the other hand, if the magnitude of the detection value is less than the threshold value in both the determinations S1 and S2, the acceleration determination unit 153 determines that it is not necessary to stop the spin tub 13. The determination S is repeated over the entire period of the third operation time T3 at a predetermined time interval (for example, 0.1 second interval). The judgment S, judgment S1, or judgment S2 is an example of a "second judgment."

[0060] (Difference between judgement S and other judgements) Next, the difference between the judgment S and other judgments (judgments K1, K2, J5, etc.) will be described. First, in the judgments K1 and K2, a judgment is made at a first period (e.g., every second) as a predetermined time interval. On the other hand, in the judgment S, a judgment is made at a second period (e.g., every 0.1 seconds) that is shorter than the first period as a predetermined time interval.

[0061] Moreover, the judgments K1 and K2 are judgments that output a judgment result to stop the rotating tub 13 when the first reference vibration is present, based on the amount of change in the detection value. In other words, the threshold value set for judgments K1 and K2 and compared with the amount of change in the detection value is set to a value at which the amount of change in the detection value is equal to or greater than the threshold value when the first reference vibration is present.

[0062] On the other hand, the judgment S is a judgment that outputs a judgment result to stop the spin tub 13 when a second reference vibration that is greater than the first reference vibration is present based on the magnitude of the acceleration. In other words, the judgment S does not output a judgment result to stop the spin tub 13 when the first reference vibration is present. The threshold value that is set for the judgment S and compared with the magnitude of the acceleration is set to a value that makes the magnitude of the acceleration less than the threshold value when the first reference vibration is present and makes the magnitude of the acceleration equal to or greater than the threshold value when the second reference vibration is present.

[0063] In this embodiment, the second reference vibration is a relatively large vibration. For example, the second reference vibration is a vibration that causes a large movement of the water tank 12 so that the water tank 12 hits the inner surface of the outer box 11. For example, the threshold value used in the judgment S is set to a value three or more times larger than the threshold value used in the judgment J5.

[0064] <4. Control flow> Next, the control flow will be described. FIG. 7 is a flowchart showing the flow of control related to the change amount determination section 152 and the acceleration determination section 153.

[0065] First, the change amount determination unit 152 determines whether or not a start condition for the determination K1 is satisfied (S101). In this embodiment, the start condition for the determination K1 is that the rotation speed of the rotation tub 13 increases beyond the number of rotations R2. If the start condition for the determination K1 is not satisfied (S101: NO), the control flow returns to the process of S101.

[0066] When the start condition of the judgment K1 is satisfied (S101: YES), the change amount judgment unit 152 samples and acquires the detected value of the acceleration, and calculates the amount of change in the acceleration (S102). Then, as the judgment K1, the change amount judgment unit 152 judges whether the amount of change in the acceleration is equal to or greater than a threshold value (S103). When the amount of change in the acceleration is equal to or greater than the threshold value (S103: YES), the change amount judgment unit 152 outputs the judgment result for stopping the spin tub 13 to the control unit 140 (S121).

[0067] On the other hand, if the amount of change in the acceleration is less than the threshold value (S103: NO), the change amount determination unit 152 determines whether or not the rotation speed of the spin tub 13 has reached the number of rotations R4 (S104). If the rotation speed of the spin tub 13 has not reached the number of rotations R4 (S104: NO), the control flow returns to the process of S102. On the other hand, if the rotation speed of the spin tub 13 has reached the number of rotations R4 (S104: YES), the change amount determination unit 152 stops the determination K1 (S105).

[0068] When the rotation speed of the spin tub 13 reaches the number of rotations R4 (S104: YES), the acceleration determination unit 153 determines whether the magnitude of the acceleration is equal to or greater than a threshold (S106) as a determination S. When the magnitude of the acceleration is equal to or greater than the threshold (S106: YES), the acceleration determination unit 153 outputs a determination result for stopping the spin tub 13 to the control unit 140 (S121).

[0069] If the magnitude of the acceleration is less than the threshold (S106: NO), the change amount determination unit 152 determines whether the initial period T3A has elapsed (S107). If the initial period T3A has not elapsed (S107: NO), the control flow returns to the process of S106.

[0070] On the other hand, if the initial period T3A has elapsed (S107: YES), the change amount determination unit 152 resumes sampling and acquiring the detected acceleration value, and calculates the amount of change in the acceleration (S108). Then, the change amount determination unit 152 determines whether the amount of change in the acceleration is equal to or greater than a threshold value, as determination K2 (S109). If the amount of change in the acceleration is equal to or greater than the threshold value (S109: YES), the change amount determination unit 152 outputs a determination result for stopping the spin tub 13 to the control unit 140 (S121).

[0071] At this time, in parallel with the processes of S108 and S109 by the change amount determination unit 152, the acceleration determination unit 153 determines whether the magnitude of the acceleration is equal to or greater than a threshold (S110) as a determination S. If the magnitude of the acceleration is equal to or greater than the threshold (S110: YES), the acceleration determination unit 153 outputs a determination result for stopping the spin tub 13 to the control unit 140 (S121).

[0072] On the other hand, when the amount of change in acceleration is less than the threshold (S109: NO) and the magnitude of acceleration is less than the threshold (S110: NO), the change amount determination unit 152 and the acceleration determination unit 153 determine whether or not the third driving time T3 has elapsed (S111). When the third driving time T3 has not elapsed (S111: NO), the control flow returns to the process of S108. On the other hand, when the third driving time T3 has elapsed (S111: YES), the change amount determination unit 152 stops the determination K2, and the acceleration determination unit 153 stops the determination S (S112). This completes a series of processes.

[0073] <5. Advantages> In recent years, in response to demands for shorter operation times, efforts have been made to shorten the spin-dry start-up time and to increase the speed of rotation of spin tub 13 during the spin-dry process (for example, increasing the maximum rotation speed). As a result, for example, increasing the speed of rotation of spin tub 13 tends to increase the centrifugal force when imbalance occurs, which increases the vibration of water tub 12. In addition, shortening the spin-dry start-up time can cause erroneous detection of abnormal vibration due to the effect of overshoot when the target rotation speed is reached, which can lead to extended operation times.

[0074] One method for suppressing false positives is to provide a judgment suppression section in which vibration detection (judgments K1 and K2) is suppressed until the overshoot converges and the rotation speed of the spin tub 13 stabilizes. On the other hand, if a judgment suppression section is provided, it may be difficult to appropriately stop the spin tub 13 if a large abnormal vibration occurs in the judgment suppression section.

[0075] In this embodiment, the washing machine 1 has a first determination unit (e.g., change amount determination unit 152) that repeatedly performs a first determination regarding the stop of the spin tub 13 based on the amount of change in the detection value obtained from the detection result of the acceleration sensor 60 during a first period (e.g., subsequent period T3B) included in the spin-drying process, and suppresses the first determination during a second period (e.g., initial period T3A) that is included in the spin-drying process and is set before the first period, and a second determination unit (e.g., acceleration determination unit 153) that repeatedly performs a second determination regarding the stop of the spin tub 13 based on the magnitude of acceleration obtained from the detection result of the acceleration sensor 60 at least during the second period (e.g., initial period T3A). According to this configuration, during the second period in which the first determination based on the amount of change in the detection value is suppressed, the second determination based on the magnitude of acceleration is performed. As a result, while suppressing erroneous detection during the second period, it is possible to stop the spin tub 13 based on the second determination when large abnormal vibration occurs during the second period. As a result, the rotation control of the washing machine 1 can be more appropriately performed.

[0076] In this embodiment, the dehydration process includes an accelerated operation time (second operation time T2) during which the rotation speed of the spin tub 13 is gradually increased, and a constant-speed operation time (third operation time T3) during which the rotation speed of the spin tub 13 is kept constant after the accelerated operation time. The first period is a period included in the constant-speed operation time. The second period is a period included in the constant-speed operation time and is a period set between the accelerated operation time and the first period. With this configuration, it is possible to suppress erroneous detection of abnormal vibration during the second period in which overshoots Ya and Yb are likely to occur, and to stop the spin tub 13 based on the second judgment when large abnormal vibration occurs during the second period. This allows the rotation control of the washing machine 1 to be performed more appropriately.

[0077] In this embodiment, the first determination unit makes the first determination based on the amount of change in the detected value of acceleration acting in radial direction D2 (or circumferential direction D3) of water tub 12. The second determination unit makes the second determination based on at least the magnitude of acceleration detected of acceleration acting in axial direction D1 of water tub 12. With this configuration, abnormal vibrations caused by imbalance can be accurately determined in the first determination, and abnormal vibrations caused by laundry stuck to the inner circumferential surface of spin tub 13 falling inside spin tub 13 can be accurately determined in the second determination.

[0078] In this embodiment, the first determination unit performs the first determination based on an amount of change in the detection value detected with respect to acceleration acting in a first direction. The second determination unit performs the second determination based on a magnitude of acceleration detected with respect to acceleration acting in the first direction, and the second determination based on a magnitude of acceleration detected with respect to acceleration acting in a second direction different from the first direction. With this configuration, the second determination is performed based on the magnitude of acceleration detected in a plurality of directions, so that the accuracy of the second determination can be further improved.

[0079] Second embodiment Next, a second embodiment will be described. The second embodiment differs from the first embodiment in the method of calculating the amount of change in the detected value related to acceleration. Note that the configuration other than that described below is the same as the first embodiment.

[0080] In this embodiment, the acceleration sensor 60 is a digital acceleration sensor. However, the acceleration sensor 60 may be an analog acceleration sensor. In this embodiment, the acceleration sensor 60 is capable of detecting acceleration acting in the circumferential direction D3 of the water tank 12. Note that the acceleration sensor 60 may be capable of detecting acceleration acting in the radial direction D2 of the water tank 12 instead of / in addition to the acceleration acting in the circumferential direction D3 of the water tank 12.

[0081] In this embodiment, the change amount determination unit 152 uses the following calculated value as the change amount of the detection value used in the determinations K1 and K2. That is, the change amount determination unit 152 stores the detection value acquired within a predetermined time range (for example, 2 seconds) in the storage unit 190 for the detection value of the acceleration sensor 60 acquired at a period of, for example, 0.1 seconds, and performs the first determination based on the magnitude of the difference between the maximum detection value and the minimum detection value acquired within the predetermined time range as the change amount of the detection value. That is, for example, for the detection value of the acceleration sensor 60 acquired at a period of, for example, 0.1 seconds, the first determination is performed based on the magnitude of the difference between the maximum detection value and the minimum detection value among a total of 20 detection values ​​including the detection value acquired 2 seconds before the current time to the detection value acquired at the current time.

[0082] According to this configuration, the amount of change in the detection value can be detected more accurately than in the first embodiment, and thus abnormal vibration can be detected more accurately and more quickly.

[0083] (Modification) Next, first to third modified examples applicable to each of the first and second embodiments will be described. The configurations of the first to third modified examples other than those described below are the same as those of the first or second embodiment.

[0084] (First Modification) In the first modified example, the threshold value used for the first judgment and / or the second judgment is changed according to the weight of the clothes stored in the spin tub 13. More specifically, in the first modified example, the first judgment (judgment K2) is made based on whether the amount of change in the detection value is equal to or greater than the first threshold value. The second judgment (judgment S) is made based on whether the magnitude of the detection value is equal to or greater than the second threshold value. At least one of the first threshold value and the second threshold value is changed according to the weight of the clothes stored in the spin tub 13 (for example, the detection result of the weight detection unit 110).

[0085] FIG. 8 is a diagram showing threshold information 191A of the first modified example. The threshold information 191A includes thresholds K2_A to K2_J for judgment K2, thresholds S1_A to S1_J for judgment S1 related to the radial direction D2 (or circumferential direction D3), and thresholds S2_A to S2_J for judgment S2 related to the axial direction D1. The thresholds K2_A to K2_J for judgment K2 correspond to clothing weights of 1 kg to 10 kg. The thresholds K2_A to K2_J for judgment K2 are set to larger values ​​as the thresholds correspond to heavier weights. Similarly, the thresholds S1_A to S1_J for judgment S1 correspond to clothing weights of 1 kg to 10 kg. The thresholds S1_A to S1_J for judgment S1 are set to larger values ​​as the thresholds correspond to heavier weights. The thresholds S2_A to S2_J for judgment S2 correspond to clothing weights of 1 kg to 10 kg. The threshold values ​​S2_A to S2_J for the determination S2 are set to larger values ​​as the threshold values ​​correspond to heavier weights.

[0086] According to this configuration, the threshold value is set according to the amount of laundry, so that abnormal vibrations can be detected with higher accuracy.

[0087] (Second Modification) In the second modified example, the threshold value used in the first judgment and / or the second judgment is changed according to the temperature detected by the temperature sensor 70. In detail, in the second modified example, the first judgment (judgment K2) is made based on whether or not the amount of change in the detection value described above is equal to or greater than the first threshold value. The second judgment (judgment S) is made based on whether or not the magnitude of the detection value described above is equal to or greater than the second threshold value. At least one of the first threshold value and the second threshold value is changed according to the temperature detected by the temperature sensor 70 (ambient temperature).

[0088] 9 is a diagram showing threshold information 191B of the second modified example. Similar to the first modified example, the threshold information 191B includes thresholds K2_A to K2_J for judgment K2, thresholds S1_A to S1_J for judgment S1 regarding the radial direction D2 (or the circumferential direction D3), and thresholds S2_A to S2_J for judgment S2 regarding the axial direction D1.

[0089] In this modification, the thresholds K2_A to K2_J for judgment K2 include thresholds K2_A(5) to K2_J(5) applied when the environmental temperature is less than 5° C., thresholds K2_A(10) to K2_J(10) applied when the environmental temperature is 5° C. or more and less than 10° C., thresholds K2_A(20) to K2_J(20) applied when the environmental temperature is 10° C. or more and less than 20° C., thresholds K2_A(30) to K2_J(30) applied when the environmental temperature is 20° C. or more and less than 30° C., and thresholds K2_A(35) to K2_J(35) applied when the environmental temperature is 30° C. or more. The thresholds K2_A to K2_J for judgment K2 are set to have smaller values ​​as the thresholds correspond to higher environmental temperatures.

[0090] Similarly, the thresholds S1_A to S1_J for judgment S1 include thresholds S1_A(5) to S1_J(5) applied when the environmental temperature is less than 5° C., thresholds S1_A(10) to S1_J(10) applied when the environmental temperature is equal to or greater than 5° C. and less than 10° C., thresholds S1_A(20) to S1_J(20) applied when the environmental temperature is equal to or greater than 10° C. and less than 20° C., thresholds S1_A(30) to S1_J(30) applied when the environmental temperature is equal to or greater than 20° C. and less than 30° C., and thresholds S1_A(35) to S1_J(35) applied when the environmental temperature is equal to or greater than 30° C. The thresholds S1_A to S1_J for judgment S1 are set to have smaller values ​​as the thresholds correspond to higher environmental temperatures.

[0091] The thresholds S2_A to S2_J for judgment S2 include thresholds S2_A(5) to S2_J(5) applied when the environmental temperature is less than 5° C., thresholds S2_A(10) to S2_J(10) applied when the environmental temperature is equal to or greater than 5° C. and less than 10° C., thresholds S2_A(20) to S2_J(20) applied when the environmental temperature is equal to or greater than 10° C. and less than 20° C., thresholds S2_A(30) to S2_J(30) applied when the environmental temperature is equal to or greater than 20° C. and less than 30° C., and thresholds S2_A(35) to S2_J(35) applied when the environmental temperature is equal to or greater than 30° C. The higher the environmental temperature, the smaller the value set for the threshold.

[0092] Here, the lower the environmental temperature, the lower (harder) the elastic modulus of the vibration isolation structure (e.g., the elastic member 54 of the support structure 15) becomes, and large acceleration becomes easier to detect. Therefore, by setting a threshold value according to the environmental temperature, abnormal vibrations can be detected with higher accuracy.

[0093] (Third Modification) In the third modified example, the threshold value used in the first judgment and / or the second judgment is changed according to the contents of the operation course. In detail, in the first modified example, the first judgment (judgment K2) is made based on whether or not the amount of change in the detection value described above is equal to or greater than the first threshold value. The second judgment (judgment S) is made based on whether or not the magnitude of the detection value described above is equal to or greater than the second threshold value. At least one of the first threshold value and the second threshold value is changed according to the contents of the operation course of the washing machine 1 that is set and executed using an operation unit or a terminal device (not shown).

[0094] FIG. 10 is a diagram showing threshold information 191C of the third modified example. The threshold information 191C includes, for example, thresholds K2_F and K2_Y for the judgment K2, thresholds S1_F and S1_Y for the judgment S1 in the radial direction D2 (or the circumferential direction D3), and thresholds S2_F and S2_Y for the judgment S2 in the axial direction D1. The thresholds K2_F, S1_F, and S2_F are thresholds used in the judgment K2, S1, and S2 corresponding to the case where the standard course weight of 6 kg is selected as the operation course of the washing machine 1. The thresholds K2_Y, S1_Y, and S2_Y are thresholds used in the judgment K2, S1, and S2 corresponding to the case where the blanket course is selected as the operation course of the washing machine 1. In this embodiment, the threshold K2_Y is larger than the threshold K2_F. The threshold S1_Y is larger than the threshold S1_F. The threshold S2_Y is larger than the threshold S2_F.

[0095] When washing large items such as blankets and futons, the amount of moisture is greater and the items are heavier than standard clothes, so the acceleration detection value tends to be larger. Therefore, by setting a threshold value according to the operation course, abnormal vibrations can be detected more accurately.

[0096] At least one of the first threshold value and the second threshold value may be set to a different value depending on the detection result of the fabric quality detection unit 120 (whether the laundry is mainly cotton-based or mainly synthetic fiber-based) instead of / in addition to the operating course.

[0097] According to at least one of the embodiments described above, the washing machine includes a first determination unit and a second determination unit. The first determination unit repeatedly performs a first determination regarding the stop of the spin tub based on the amount of change in the detection value obtained from the detection result of the acceleration sensor during a first period included in the spin-drying process, and suppresses the first determination during a second period included in the spin-drying process and set before the first period. The second determination unit repeatedly performs a second determination regarding the stop of the spin tub based on the magnitude of acceleration obtained from the detection result of the acceleration sensor at least during the second period. This configuration provides a washing machine that can perform more appropriate rotation control.

[0098] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0099] 1...washing machine, 11...outer box, 12...water tub, 13...rotating tub, 14...drive unit, 15...support structure, 41...motor, 42...agitating member, 60...acceleration sensor (acceleration detection unit), 100...control device, 110...weight detection unit, 120...cloth quality detection unit, 130...rotation speed detection unit, 140...control unit, 150...spin-drying operation determination unit, 151...imbalance determination unit, 152...change amount determination unit (first determination unit), 153...acceleration determination unit (second determination unit).

Claims

1. Aquarium and A rotating tub is disposed within the water tub and receives clothes; A motor that rotates the rotating tub; an acceleration sensor provided in association with the water tank; A control unit that controls the motor and executes a dehydration process to rotate the rotating tub; a first determination unit that repeatedly performs a first determination regarding the stop of the spin tub based on an amount of change in a detection value obtained from a detection result of the acceleration sensor during a first period included in the spin-drying process, and suppresses the first determination during a second period that is included in the spin-drying process and is set before the first period; a second determination unit that repeatedly performs a second determination regarding the stop of the spin tub based on a magnitude of acceleration obtained from a detection result of the acceleration sensor during at least the second period; Equipped with a washing machine.

2. the dehydration step includes an increased speed operation time during which the rotation speed of the rotating tub is gradually increased, and a constant speed operation time during which the rotation speed of the rotating tub is kept constant after the increased speed operation time, the first period is a period included in the constant speed driving time, The second period is a period included in the constant speed driving time and is set between the increased speed driving time and the first period. The washing machine according to claim 1.

3. The first determination is a determination to stop the rotating tub when a first reference vibration is present based on an amount of change in the detection value, The second determination is a determination to stop the spin tub when a second reference vibration greater than the first reference vibration is present based on the magnitude of the acceleration. The washing machine according to claim 1 or 2.

4. the first determination unit sequentially acquires the detection value at a predetermined time interval during the first period, and performs the first determination based on a magnitude of a difference between the previously acquired detection value and the most recently acquired detection value as an amount of change in the detection value; The washing machine according to claim 1 or 2.

5. the first determination unit stores the detection values ​​acquired within a predetermined time range during the first period, and performs the first determination based on a magnitude of a difference between a maximum detection value and a minimum detection value acquired within the predetermined time range as an amount of change in the detection value. The washing machine according to claim 1 or 2.

6. The first determination unit performs the first determination based on an amount of change in the detection value detected regarding acceleration acting in a radial direction or a circumferential direction of the water tank, The second determination unit performs the second determination based on at least a magnitude of the acceleration detected regarding the acceleration acting in an axial direction of the water tank. The washing machine according to claim 1 or 2.

7. The first determination unit performs the first determination based on an amount of change in the detection value detected regarding the acceleration acting in a first direction, The second determination unit performs the second determination based on a magnitude of the acceleration detected with respect to the acceleration acting in the first direction, and the second determination based on a magnitude of the acceleration detected with respect to the acceleration acting in a second direction different from the first direction. The washing machine according to claim 1 or 2.

8. the first determination is performed based on whether or not an amount of change in the detection value is equal to or greater than a first threshold value; The second determination is performed based on whether or not a magnitude of the acceleration is equal to or greater than a second threshold value, At least one of the first threshold value and the second threshold value is changed according to the weight of the clothes accommodated in the spin tub. The washing machine according to claim 1 or 2.

9. Further comprising a temperature sensor capable of detecting an external environmental temperature of the washing machine, the first determination is performed based on whether or not an amount of change in the detection value is equal to or greater than a first threshold value; The second determination is performed based on whether or not a magnitude of the acceleration is equal to or greater than a second threshold value, At least one of the first threshold value and the second threshold value is changed in response to the environmental temperature detected by the temperature sensor. The washing machine according to claim 1 or 2.

10. the first determination is performed based on whether or not an amount of change in the detection value is equal to or greater than a first threshold value; The second determination is performed based on whether or not a magnitude of the acceleration is equal to or greater than a second threshold value, At least one of the first threshold value and the second threshold value is changed depending on the content of the driving course. The washing machine according to claim 1 or 2.

Images