WO2020108431A1

WO2020108431A1 - Dewatering machine

Info

Publication number: WO2020108431A1
Application number: PCT/CN2019/120588
Authority: WO
Inventors: 佐藤弘树; 宫地成佳
Original assignee: 青岛海尔洗衣机有限公司; Aqua株式会社
Priority date: 2018-11-26
Filing date: 2019-11-25
Publication date: 2020-06-04
Also published as: JP2020081404A; JP7252534B2; CN112601851A; CN112601851B

Abstract

A dewatering machine, capable of monitoring abnormal vibrations in stable rotation of a rotary tub for dewatering washing objects. The dewatering machine (1) comprises: a motor (6) for enabling the rotation of a rotary tub (4) of a dewatering tub (16), an acceleration sensor (27) for detecting vibration of the dewatering tub (16), and a control unit (21). The control unit (21) is configured to control the motor (6), so that the rotational speed of the motor (6) increases to a specified dewatering rotational speed and then the motor stably rotates at the dewatering rotational speed, so as to dewater the washing objects (Q) in the rotary tub (4). The control unit (21) acquires a peak-to-peak value of a detection value of the acceleration sensor (27) during each of a plurality of sampling periods in the stable rotation of the motor (6) at the dewatering rotational speed. If the peak-to-peak value is equal to or greater than a specified threshold, the control unit (21) adds one to the count value. When the count value reaches a specified value, the control unit (21) determines that there is an imbalance of a specified or larger size in the rotary tub (4).

Description

Dehydrator

Technical field

The invention relates to a dehydrator.

Background technique

The drum-type washing machine disclosed in the following Patent Document 1 includes a washing machine box, a water tub rotatably disposed in the washing machine box, a rotating drum rotatably disposed in the water tub, a motor that rotationally drives the rotating drum, and The control unit that controls the motor. The water tub, rotating drum and motor constitute a water tub unit. The drum-type washing machine includes a vibration detection section that detects vibration of the water tub unit. During the spin-drying operation of the drum-type washing machine, the control unit gradually rotates the rotary drum at the highest spin speed after the rotation speed of the rotary drum is increased in stages. When the rotation of the rotating drum increases, when the deviation of the laundry in the rotating drum, that is, the so-called imbalance is large, the ratio of the increase in the vibration value detected by the vibration detection unit in the predetermined detection cycle to the detection cycle Exceed the specified value. In this way, the control unit detects abnormal vibration of the water drum unit, the rotation speed of the rotating drum stops increasing, and the rotation speed at the time of stopping the increase is set as the maximum spin speed.

During the stable rotation of the rotating drum at the highest spin speed, the imbalance may increase depending on the situation where the laundry is discharged from the rotating drum. When the imbalance becomes larger, the water tank unit may vibrate abnormally. In the spin-drying operation of the drum-type washing machine of Patent Document 1, although the abnormal vibration is monitored while the rotation speed of the rotary drum is increasing, the abnormal vibration is not monitored while the rotary drum rotates steadily at the highest spin speed.

Existing technical literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2018-68325

Summary of the invention

Problems to be solved by the invention

The present invention has been made under such a background, and an object of the present invention is to provide a dehydrator capable of monitoring abnormal vibration during stable rotation of a rotary tub for dehydrating laundry.

Solutions for solving problems

The present invention is a dehydration machine, including: a box; a dehydration bucket, a rotating bucket containing laundry and a water bucket containing the rotating bucket, arranged in the box; a motor to rotate the rotating bucket; a supporting member , Connect the dewatering barrel with the box, elastically support the dewatering barrel; acceleration sensor, detect the vibration of the dewatering barrel during the rotation of the rotating barrel; a motor control unit, control the motor so that After the rotation speed of the motor rises to a predetermined dehydration rotation speed, it rotates steadily at the dehydration rotation speed to dehydrate the laundry in the rotary tub; the acquisition unit has many of the stable rotations of the motor at the dehydration rotation speed During each sampling period, obtain the peak-to-peak value of the detection value of the acceleration sensor; the counting unit, when the peak-to-peak value is above a prescribed threshold, increase the count value with an initial value of zero by 1; and unbalance The judging unit, when the count value reaches a predetermined value, judges that there is an imbalance of a predetermined size or more in the rotating bucket.

In addition, the present invention is characterized in that, when the unbalance determination unit determines that there is an unbalance of a predetermined size or more in the rotating tub, the motor control unit stops the rotation of the motor.

In addition, the present invention is characterized in that the dehydrator further includes a rotation speed sensor that detects the rotation speed of the motor, and the acquisition unit sets each of the sampling periods to be obtained based on the rotation speed detected by the rotation speed sensor The rotating period of the rotating barrel is long.

In addition, the present invention is characterized in that the dehydrator further includes: a first irregular vibration judgment unit that, in any of the sampling periods, when the increase or decrease in the detection value of the acceleration sensor is switched more than a predetermined number of times, It is judged that the first irregular vibration has occurred in the dehydration bucket.

In addition, the present invention is characterized in that the dehydrator further includes: a second irregular vibration judging unit, which judges that a second abnormality has occurred in the dehydration bucket when the increase or decrease in the peak-to-peak value is repeated more than a prescribed number of times Regular vibration.

Invention effect

According to the present invention, in the dehydrator, the rotating tub constituting the dewatering tub rotates stably at a high rotation speed corresponding to the dehydration rotation speed of the motor, whereby the laundry in the rotating tub is dehydrated. During each of a plurality of sampling periods during which the rotating drum rotates steadily, the vibration of the dewatering drum is detected by the acceleration sensor to obtain the peak-to-peak value of the detection value of the acceleration sensor. If the unbalance of the rotating barrel during stable rotation is small, the peak-to-peak value shifts approximately constant. On the other hand, when the unbalance of the rotating barrel becomes larger, the peak-to-peak value also becomes larger. When the peak-to-peak value increases above the specified threshold, the count value is incremented. When 1 is added until the count value reaches the specified value, it is determined that there is an imbalance in the rotating drum that causes the dehydration bucket to vibrate abnormally and exceeds a prescribed size. In this way, the abnormal vibration of the dewatering bucket caused by the imbalance in the stable rotation of the rotating drum can be monitored based on the peak-to-peak value.

In addition, according to the present invention, in the dehydrator, when it is judged that there is an imbalance of a predetermined size or more in the rotating drum, the rotation of the motor is stopped, and therefore, the processing can be appropriately performed so that the abnormal vibration is not eliminated Continue to rotate the barrel at high speed.

Furthermore, according to the present invention, each sampling period is set to be longer than the rotation period of the rotating tub obtained from the instantaneous rotation speed of the motor detected by the rotation speed sensor. Thus, during each sampling period, the vibration of the dewatering bucket during the period in which the rotating drum rotates more than one revolution can be detected by the acceleration sensor. Therefore, it is possible to obtain a peak-to-peak value effective for determining that there is an imbalance of a predetermined size or more.

In addition, according to the present invention, for example, when the support member that elastically supports the dehydration bucket ages, a first irregular vibration occurs in the dehydration bucket, and the first irregular vibration is an increase or decrease in the detection value of the acceleration sensor in any one sampling period The vibration is switched more than a predetermined number of times. The first irregular vibration is a type of abnormal vibration. Therefore, in the dehydrator, during the stable rotation of the rotating tub, the abnormal vibration of the dewatering tub caused by the aging of the support member and the like can be monitored based on the number of switching of the increase or decrease in the detection value of the acceleration sensor during the sampling period.

In addition, according to the present invention, in the stable rotation of the rotating tub, for example, when the water tub constituting the dewatering tub periodically comes into contact with the tank due to some abnormality, a second irregular vibration occurs in the dewatering tub. Regular vibration is a vibration in which continuously acquired peak-to-peak values do not constantly change, but increase and decrease repeat a predetermined number of times or more. The second irregular vibration is a type of abnormal vibration. In the dehydrator, during the stable rotation of the rotary drum, the abnormal vibration of the dehydration drum caused by a certain abnormality can be monitored according to the number of repetitions of the increase and decrease of the peak-to-peak value.

BRIEF DESCRIPTION

Fig. 1 is a schematic longitudinal right side view of a dehydrator according to an embodiment of the present invention.

2 is a block diagram showing the electrical configuration of the dehydrator.

FIG. 3 is a time chart showing the state of the rotation speed of the motor of the dehydrator during the dehydration operation.

FIG. 4 is a time chart showing vibrations occurring in the dehydration tub during the dehydration operation.

Fig. 5 is a timing chart showing vibrations occurring in the dehydration tub during the dehydration operation.

6 is a graph showing the relationship between the threshold value related to the peak-to-peak value of the detection value of the acceleration sensor and the rotation speed of the motor.

7 is a flowchart showing the initial processing in the spin-drying operation.

FIG. 8 is a flowchart showing the processing of detection 1 during the spin-drying operation.

9 is a flowchart showing the processing of detection 2 during the spin-drying operation.

FIG. 10 is a time chart showing the first irregular vibration that occurs in the dehydration tub during the dehydration operation.

FIG. 11 is a flowchart showing the process of detection 2 of the first modification.

FIG. 12 is a timing chart showing the second irregular vibration occurring in the dehydration tank during the dehydration operation.

13 is a flowchart showing the processing of detection 2 of the second modification.

DESCRIPTION OF REFERENCE NUMERALS

1: dehydrator; 2: box; 3: bucket; 4: rotating bucket; 6: motor; 10: support member; 16: dehydration bucket; 21: control unit; 26: speed sensor; 27: acceleration sensor; A: Rotation speed; F: count value; pp: peak-to-peak value; Q: laundry; S: sampling period; T: rotation period.

detailed description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic longitudinal right side view of a dehydrator 1 according to an embodiment of the present invention. The direction perpendicular to the paper surface of FIG. 1 is referred to as the left-right direction X of the dehydrator 1, the left-right direction in FIG. 1 is referred to as the front-rear direction Y of the dehydrator 1, and the up-down direction in FIG. 1 is referred to as the Up and down direction Z. The left-right direction X, the front-rear direction Y, and the up-down direction Z are perpendicular to each other to form a three-dimensional. The left-right direction X may be called the X-axis direction, the front-back direction Y may be called the Y-axis direction, and the up-down direction Z may be called the Z-axis direction. In the left-right direction X, the back side of the paper surface of FIG. 1 is referred to as the left side X1 of the dehydrator 1, and the front side of the paper surface of FIG. 1 is referred to as the right side X2 of the dehydrator 1. Among the front and rear directions Y, the left side in FIG. 1 is referred to as the front side Y1, and the right side in FIG. 1 is referred to as the rear side Y2. Among the vertical directions Z, the upper side is referred to as an upper side Z1, and the lower side is referred to as a lower side Z2.

The dehydrator 1 includes all devices that can perform the dehydration operation of the laundry Q. Therefore, the dehydrator 1 includes not only a device that performs only a dehydration operation, but also a washing machine that performs a washing operation such as a washing operation, a rinsing operation, and a dehydration operation, or an integrated washing and drying machine that performs a drying operation in addition to the washing operation. Hereinafter, the dehydrator 1 will be described using a washing machine as an example.

The dehydrator 1 includes a tank 2, a water tub 3 disposed in the tank 2, a rotating tub 4 housed in the water tub 3, a rotating wing 5 disposed in the lower portion of the rotating tub 4, a rotating bucket 4 or a rotating wing 5 The rotating electric motor 6 and the transmission mechanism 7 that transmits the driving force of the motor 6 to the rotating tub 4 and the rotating wing 5.

The case 2 is made of metal, for example, and is formed in a box shape. The upper surface portion 2A of the cabinet 2 is formed to be inclined with respect to the front-back direction Y so as to extend toward the upper side Z1 as approaching the rear side Y2, for example. In the upper surface portion 2A, an opening 2B that communicates the inside and outside of the case 2 is formed. A door 8 that opens/closes the opening 2B is provided in the upper surface portion 2A. In the upper surface portion 2A, for example, a region closer to the front side Y1 than the opening 2B is provided with a display operation portion 9 composed of a switch, a liquid crystal panel, or the like. The user can freely select the operating conditions of the dehydrator 1 or instruct the dehydrator 1 to start or stop the operation by operating a switch or the like of the display operation unit 9. Information related to the operation of the dehydrator 1 can be visually displayed on the liquid crystal panel of the display operation unit 9 or the like.

The water tub 3 is made of resin, for example, and is formed into a bottomed cylindrical shape. The water tub 3 is connected to the case 2 via a support member 10 such as a boom having a spring and a damping mechanism, a shock absorber, and is elastically supported by the support member 10. The bucket 3 has a substantially cylindrical circumferential wall 3A arranged in the up-down direction Z, a bottom wall 3B that blocks the hollow portion of the circumferential wall 3A from the lower side Z2, and an edge that surrounds the upper side Z1 side of the circumferential wall 3A and An annular ring wall 3C protruding toward the center of the circumferential wall 3A. On the inner side of the annular wall 3C, a port 3D communicating with the hollow portion of the circumferential wall 3A from the upper side Z1 is formed. The entrance 3D is in a state of facing and communicating with the opening 2B of the cabinet 2 from the lower side Z2. In the annular wall 3C, a door 11 that opens/closes the entrance 3D is provided. The bottom wall 3B is formed in a disk shape extending substantially horizontally, and a through hole 3E penetrating the bottom wall 3B is formed at the center of the bottom wall 3B.

Water can be stored in the bucket 3. In the water tub 3, a water supply path 12 connected to a tap of tap water is connected from the upper side Z1, and tap water is supplied into the water tub 3 from the water supply path 12. In the middle of the water supply path 12, a water supply valve 13 that is opened/closed to start or stop water supply is provided. The drain channel 14 is connected to the water tub 3 from the lower side Z2, and the water in the water tub 3 is discharged from the drain channel 14 to the outside of the machine. In the middle of the drainage path 14, a drainage valve 15 is provided that is opened/closed to start or stop drainage.

The rotating tub 4 is made of, for example, a metal, and is formed into a bottomed cylindrical shape that is one circle smaller than the water tub 3, and can store laundry Q inside. The rotating tub 4 has a substantially cylindrical circumferential wall 4A arranged in the vertical direction Z, and a bottom wall 4B that blocks the hollow portion of the circumferential wall 4A from the lower side Z2.

The inner circumferential surface of the circumferential wall 4A is the inner circumferential surface of the rotary tub 4. The upper end portion of the inner peripheral surface of the circumferential wall 4A is a port 4C that exposes the hollow portion of the circumferential wall 4A to the upper side Z1. The port 4C is in a state of facing and communicating with the port 3D of the water tub 3 from the lower side Z2. The entrance 3D and the entrance 4C are opened/closed together through the door 11. The user of the dehydrator 1 drops the laundry Q into the rotary tub 4 via the opened opening 2B, the entrance 3D, and the entrance 4C.

The rotating tub 4 is accommodated in the water tub 3 in a coaxial state. The water tub 3 and the rotating tub 4 constitute a dewatering tub 16. The entire dewatering bucket 16 is elastically supported by the support member 10. The rotating tub 4 accommodated in the water tub 3 can rotate about an axis J that constitutes its central axis and extends in the vertical direction Z. In addition, at least one of the circumferential wall 4A and the bottom wall 4B of the rotating tub 4 is formed with a plurality of through holes (not shown) through which water in the water tub 3 can travel between the water tub 3 and the rotating tub 4 through the through holes between. Therefore, the water level in the water tub 3 matches the water level in the rotating tub 4.

The bottom wall 4B of the rotating tub 4 is formed in a circular plate shape extending substantially parallel to the bottom wall 3B of the water tub 3 at an interval on the upper side Z1, and a through bottom wall is formed at a center position of the bottom wall 4B that coincides with the axis J 4B through hole 4D. The bottom wall 4B is provided with a tubular support shaft 17 that surrounds the through hole 4D and extends along the axis J to the lower side Z2. The support shaft 17 is inserted into the through hole 3E of the bottom wall 3B of the water tub 3, and the lower end portion of the support shaft 17 is located on the lower side Z2 of the bottom wall 3B.

The rotary wing 5, also known as a so-called pulsator, is formed in a disc shape with the axis J as the center, and is arranged in the rotary drum 4 concentrically with the rotary drum 4 along the bottom wall 4B. On the upper surface portion of the rotary wing 5 facing the entrance 4C of the rotary tub 4, a plurality of blades 5A arranged radially are provided. The rotary wing 5 is provided with a rotary shaft 18 extending from the center of the circle along the axis J to the lower side Z2. The rotating shaft 18 is inserted into the hollow portion of the support shaft 17, and the lower end of the rotating shaft 18 is located on the lower side Z2 of the bottom wall 3B of the water tub 3.

The motor 6 is composed of, for example, an inverter motor. The motor 6 is arranged in the tank 2 on the lower side Z2 of the water tub 3. The motor 6 has an output shaft 19 that rotates around the axis J. The transmission mechanism 7 is located between the lower ends of the support shaft 17 and the rotating shaft 18 and the upper end of the output shaft 19. The transmission mechanism 7 selectively transmits the driving force output by the motor 6 from the output shaft 19 to one or both of the support shaft 17 and the rotation shaft 18. As the transmission mechanism 7, a well-known transmission mechanism can be used. In this embodiment, the motor 6 and the transmission mechanism 7 are fixed to the water tub 3, but the motor 6 and the transmission mechanism 7 may be fixed to the case 2, and the driving force of the motor 6 is transmitted from the transmission mechanism 7 to the support shaft via a transmission member such as a transmission belt 17. Rotating shaft 18.

FIG. 2 is a block diagram showing the electrical configuration of the dehydrator 1. The dehydrator 1 includes a motor control unit, an acquisition unit, a counting unit, an unbalance determination unit, and a control unit 21 as an example of the first irregular vibration determination unit and the second irregular vibration determination unit. The control unit 21 is configured to include, for example, a CPU 22; a memory 23 such as a ROM and a RAM; and a timer 24 for timing, and is built in the case 2 (see also FIG. 1). The memory 23 stores various count values and the like described later.

The dehydrator 1 further includes a water level sensor 25, a rotation speed sensor 26, and an acceleration sensor 27. The motor 6, the transmission mechanism 7, the water supply valve 13, the drain valve 15, the display operation unit 9, the water level sensor 25, the rotation speed sensor 26, and the acceleration sensor 27 are electrically connected to the control unit 21, respectively.

The control unit 21 controls the rotation of the motor 6 to generate a driving force for the motor 6 or stop the rotation of the motor 6. The control unit 21 controls the transmission mechanism 7 to switch the transmission target of the driving force of the motor 6 to one or both of the support shaft 17 and the rotation shaft 18. When the driving force of the motor 6 is transmitted to the support shaft 17, the rotary tub 4 rotates around the support shaft 17. When the driving force of the motor 6 is transmitted to the rotary shaft 18, the rotary wing 5 rotates around the rotary shaft 18. The control section 21 controls the opening/closing of the water supply valve 13 and the drain valve 15. When the control unit 21 opens the water supply valve 13 in a state where the drain valve 15 is closed, the control unit 21 supplies water to the dewatering tank 16 to store water. When the control part 21 opens the drain valve 15, the dewatering tub 16 drains. When the user operates the display operation section 9 to select the dehydration condition of the laundry Q or the like, the control section 21 receives the selection. The control unit 21 controls the display of the display operation unit 9.

The water level sensor 25 is a sensor that detects the water level of the dewatering tank 16, that is, the water levels of the water tank 3 and the rotating tank 4, and the detection result of the water level sensor 25 is input to the control unit 21 in real time. The rotation speed sensor 26 is a device that detects the rotation speed of the motor 6, strictly speaking, the rotation speed of the output shaft 19 of the motor 6, and is composed of a Hall IC, for example. The rotational speed instantly read by the rotational speed sensor 26 is input to the control unit 21 in real time. The control unit 21 rotates the motor 6 at a desired rotation speed based on the input rotation speed, for example, by controlling the duty ratio of the voltage applied to the motor 6. In the present embodiment, the rotation speed of the rotary tub 4 is the same as the rotation speed of the motor 6, and the rotation speed of the rotary wing 5 is a value obtained by multiplying a predetermined constant such as the reduction ratio of the transmission mechanism 7 and the rotation speed of the motor 6. In short, by detecting the rotation speed of the motor 6, the rotation speed sensor 26 also detects the respective rotation speeds of the rotary tub 4 and the rotary wing 5.

When the rotary tub 4 rotates, the dewatering barrel 16 vibrates with the rotary wing 5, the motor 6, and the transmission mechanism 7. The acceleration sensor 27 is attached to, for example, the outer peripheral surface of the water tub 3 (see FIG. 1 ), and detects the vibration of the dewatering tub 16 when the rotating tub 4 rotates. Specifically, the acceleration sensor 27 detects accelerations in three directions of the X-axis direction, the Y-axis direction, and the Z-axis direction in the vibrating dewatering bucket 16 as detection values. The acceleration in the left-right direction X is the vibration component in the X-axis direction among the vibrations of the dewatering bucket 16. The acceleration in the front-rear direction Y is the vibration component in the Y-axis direction among the vibrations of the dewatering tub 16. The acceleration in the vertical direction Z is a vibration component in the Z-axis direction among the vibrations of the dewatering bucket 16. The detection value of the acceleration sensor 27 changes according to the rotation speed of the motor 6, and specifically increases according to the square of the rotation speed of the motor 6.

During the washing operation, the control unit 21 supplies water to the dewatering tub 16 for a predetermined time, and the rotor 6 is rotated by the motor 6. As a result, the laundry Q in the rotary tub 4 is agitated by the rotary rotor blade 5 or the detergent put into the rotary tub 4 before the start of the cleaning operation decomposes dirt and is washed. In the rinsing operation after the washing operation, the control unit 21 supplies water to the dewatering tub 16 for a predetermined time, and the rotor 6 is rotated by the motor 6. Thus, the laundry Q in the rotating tub 4 is rinsed by the flow of tap water generated in the rotating tub 4 by the rotating rotor blade 5. The rinsing operation can be performed multiple times.

Next, the spin-drying operation will be described in detail. FIG. 3 is a time chart showing the state of the rotation speed of the motor 6 in one dehydration operation performed by the dehydrator 1. In the timing chart of FIG. 3, the horizontal axis represents the elapsed time (unit: minutes), and the vertical axis represents the rotation speed of the motor 6 (unit: rpm).

As the dehydration operation starts, the control unit 21 starts the rotation of the rotary tub 4. Specifically, first, the control unit 21 controls the motor 6 so that the rotation speed of the motor 6 rises to a predetermined initial rotation speed such as 120 rpm, and then rotates stably at the initial rotation speed. Thus, the rotating tub 4 also rotates stably at the initial rotation speed. Then, the control unit 21 controls the motor 6 so that the motor 6 rises from 120 rpm to a predetermined intermediate rotation speed such as 240 rpm, and then rotates stably at the intermediate rotation speed. Thereby, the rotating tub 4 also rotates stably at an intermediate rotation speed. During the spin-drying operation, when the rotation speed of the motor 6 is, for example, 50 rpm or more and 60 rpm or less, lateral resonance occurs in the rotary tub 4, and when the rotation speed of the motor 6 is, for example, 200 rpm or more and 220 rpm or less, longitudinal resonance occurs in the rotary tub 4. Therefore, the initial rotation speed and the intermediate rotation speed are set to values that avoid the rotation speed of the motor 6 when lateral resonance and longitudinal resonance occur.

After the motor 6 rotates steadily at an intermediate rotation speed, the control section 21 controls the motor 6 so that the rotation speed of the motor 6 rises from 240 rpm to a predetermined spin speed such as 800 rpm or more and 1000 rpm or less, and then rotates steadily at the spin speed. Thus, the rotary tub 4 also rotates stably at the spin speed. By the centrifugal force generated by the stable rotation of the rotary tub 4 at the spin speed, the laundry Q in the rotary tub 4 is officially dehydrated. The drain valve 15 in the dehydration operation is in an open state, and the water seeping out of the laundry Q by dehydration is discharged through the drain path 14. When the rotary tub 4 continues to rotate stably at a spin speed for a predetermined time, the control unit 21 stops the rotation of the motor 6. Thus, the spin-drying operation ends. In the spin-drying operation, there are an intermediate spin-drying operation performed between the washing operation and the rinse operation, and a final spin-drying operation performed after the last rinse operation. During the intermediate dehydration operation and the final dehydration operation, the stable rotation time of at least one of the initial rotation speed, the intermediate rotation speed, and the dehydration rotation speed is different. Specifically, the stable rotation time during the final spin-drying operation is set to be longer than the stable rotation time during the intermediate spin-drying operation. In this embodiment, the spin-drying operation will be described without distinguishing between the intermediate spin-drying operation and the final spin-drying operation.

4 and 5 are timing charts showing vibrations that occur in the dewatering tub 16 when the rotary tub 4 rotates during the dehydration operation. In the timing charts of FIGS. 4 and 5, the horizontal axis represents the elapsed time (unit: milliseconds), and the vertical axis represents the detection value (unit) of the acceleration sensor 27 in any one of the X-axis direction, the Y-axis direction, and the Z-axis direction : For example, mm/ms ² ). When the laundry Q in the rotary tub 4 is in a state of being biasedly arranged in the circumferential direction of the rotary tub 4, the laundry Q in the rotary tub 4 is biased. This bias is called imbalance. When the imbalance is small, the rotating barrel 4 rotates steadily. Therefore, even if the detection value of the acceleration sensor 27 is a detection value in any one of the X-axis direction, the Y-axis direction, and the Z-axis direction, it will be depicted as shown in FIG. 4 The continuous waveform shown. The difference between the maximum value max and the minimum value min of the detected value in the waveform W related to one cycle in the continuous waveform is called Peak-to-peak value pp. When the imbalance is small, the detected value of the acceleration sensor 27 is drawn as a sine wave, and thus the maximum value max and the minimum value min of the respective waveforms W are constant, and therefore the peak-to-peak value pp transitions substantially constant.

On the other hand, when the imbalance becomes larger, the detection value of the acceleration sensor 27 in at least any one of the X-axis direction, the Y-axis direction, and the Z-axis direction changes. As shown in FIG. 5, the waveform W changes from the waveform W1 A large change to the waveform W2. The peak-to-peak value pp of the waveform W2 is larger than the peak-to-peak value pp of the waveform W1. That is, if the imbalance becomes larger, the peak-to-peak value pp becomes larger.

The peak-to-peak value pp has a threshold set by experiment or the like. The peak-to-peak value pp is normal if it is smaller than the threshold. 6 is a graph showing the relationship between the threshold value of the peak-to-peak value pp and the rotation speed of the motor 6. In the graph of FIG. 6, the horizontal axis represents the rotation speed (unit: rpm) of the motor 6, and the vertical axis represents the threshold value of the peak-to-peak value pp in any one of the X-axis direction, the Y-axis direction, and the Z-axis direction (unit: For example, mm/ms ² ). The threshold is obtained, for example, as a function of the rotation speed of the motor 6 as a variable, and the threshold becomes larger as the rotation speed increases. Figure 6 shows a graph of this function. This function is, for example, a linear function, and is stored in the memory 23. It should be noted that due to the accuracy of the acceleration sensor 27, it is difficult to obtain the correct peak-to-peak value pp when the rotation speed of the motor 6 is less than 120 rpm. Therefore, the threshold value is set when the rotation speed of the motor 6 is 120 rpm or more. This function can be set to three types according to the respective peak-to-peak values pp in the X-axis direction, the Y-axis direction, and the Z-axis direction, or the threshold value of the peak-to-peak values in all directions can be calculated by one function.

When the peak-to-peak value pp repeatedly reaches the threshold value or more and the spin-drying operation is performed in a state where the unbalance of the rotary drum 4 is large, the rotary drum 4 vibrates abnormally, which may cause problems such as noise in the dehydrator 1. Therefore, during the spin-drying operation, the controller 21 monitors the peak-to-peak value pp to detect the presence or absence of abnormal vibration in the rotary tub 4. As such a detection, the control section 21 performs two types of electrical detections, detection 1 and detection 2. Detection 1 is performed during the start-up period in which the rotation speed of the motor 6 is above the initial rotation speed and less than the spin-drying rotation speed, and detection 2 is performed during the main spin-drying period in which the motor 6 rotates stably at the spin-drying rotation speed after the start-up period (refer to FIG. 3 ).

7 is a flowchart showing the initial processing in the spin-drying operation. When the spin-drying operation starts, the control unit 21 initializes, that is, resets the count value i and the count value F used later to zero (step S1), and starts the rotation of the motor 6 (step S2). The initial values of the count value i and the count value F are zero. When the rotation speed of the motor 6 rises to reach the initial rotation speed (120 rpm in this embodiment) (YES in step S3), the control unit 21 increases the rotation speed of the motor 6 in stages and executes detection 1 during the start-up period (Step S4). The rotational speed of the motor 6 that is stably rotating at the initial rotational speed is not always constant at the initial rotational speed, but slightly fluctuates based on the initial rotational speed. The same is true for the rotation speed of the motor 6 at the stable rotation at the intermediate rotation speed and the spin speed.

8 is a flowchart showing detection 1. With the start of detection 1, the control unit 21 obtains the instantaneous rotation speed A of the motor 6 at the current time through the rotation speed sensor 26, calculates the rotation period T of the motor 6 from the instantaneous rotation speed A by a known method, and calculates the sampling based on the rotation period T Period S (step S11). The rotation period T is also the rotation period of the rotating barrel 4. The sampling period S is obtained by multiplying the rotation period T by a constant α of 1 or more. Therefore, the sampling period S is longer than the rotation period T (see FIG. 4). In the present embodiment, the constant α is set to be less than 2, and specifically set to 1.5. Therefore, the sampling period S has a length corresponding to 1.5 cycles.

Next, the control unit 21 resets the timer 24 and the acceleration sensor 27 (step S12). As a result, the measured value t of the timer 24 and the maximum value max and the minimum value min of the detection values of the acceleration sensors 27 in the X-axis direction, the Y-axis direction, and the Z-axis direction are initialized to zero. In addition, regarding the detection value in the X-axis direction, the maximum value max may be referred to as a maximum value Xmax, and the minimum value min may be referred to as a minimum value Xmin. Similarly, for the detection value in the Y axis direction, the maximum value max is sometimes referred to as the maximum value Ymax, and the minimum value min is referred to as the minimum value Ymin, and for the detection value in the Z axis direction, the maximum value max is sometimes referred to as the maximum value Zmax, The minimum value min is called the minimum value Zmin.

Next, the control unit 21 starts counting by the timer 24 (step S13). As a result, the measured value t of the timer 24 increases by 1 millisecond every time. After the timing is started, the control unit 21 acquires the detection value of the acceleration sensor 27 in units of 1 millisecond, specifically, the respective accelerations in the X-axis direction, the Y-axis direction, and the Z-axis direction (step S14). When the measured value t of the timer 24 reaches the sampling period S, that is, when the sampling period S has elapsed since the timing in step S13 (YES in step S15), the control unit 21 selects 1 within the sampling period S Among the many detection values continuously obtained in milliseconds, obtain the maximum value max and minimum value min in the X-axis direction, Y-axis direction and Z-axis direction, that is, obtain the maximum value Xmax, the minimum value Xmin, the maximum value Ymax, the minimum value The value Ymin, the maximum value Zmax, and the minimum value Zmin (step S16).

Then, the control unit 21 executes feedback control based on the maximum value max, the minimum value min, and the like acquired in step S16. Specifically, first, the control unit 21 acquires the respective peak-to-peak values pp and threshold values in the X-axis direction, the Y-axis direction, and the Z-axis direction (step S17). The control unit 21 acquires the respective peak-to-peak values pp in the X-axis direction, the Y-axis direction, and the Z-axis direction based on the maximum value max and the minimum value min. The peak-to-peak value Xpp in the X-axis direction is obtained by subtracting the minimum value Xmin from the maximum value Xmax. The peak-to-peak value Ypp in the Y-axis direction is obtained by subtracting the minimum value Ymin from the maximum value Ymax. The peak-to-peak value Zpp in the Z-axis direction is obtained by subtracting the minimum value Zmin from the maximum value Zmax. The control unit 21 obtains the threshold value corresponding to the instantaneous rotation speed A by substituting the instantaneous rotation speed A acquired in step S11 into the above function (refer to FIG. 6 ). It should be noted that the threshold can also be obtained in step S11.

If the peak-to-peak value Xpp, the peak-to-peak value Ypp, and the peak-to-peak value Zpp are respectively less than the corresponding threshold value, the unbalance of the rotating barrel 4 is small, which is a level that does not cause a problem. In this case (YES in step S18), the control unit 21 confirms whether the rotation speed of the motor 6 at the current time reaches the target spin speed (here, 1000 rpm) (step S19). If the rotation speed of the motor 6 reaches the target spin speed (YES in step S19), the control section 21 ends detection 1 and executes detection 2 (step S20). Thereby, detection 2 is performed in a state where the motor 6 rotates steadily at the same spin speed as the target spin speed. If the rotation speed of the motor 6 is smaller than the target spin speed (NO in step S19), the control section 21 repeats the processing of steps S11 to S19. Thus, the comparison between the peak-to-peak value pp and the threshold value is repeated in units of the new sampling period S.

If at least one of the peak-to-peak value Xpp, the peak-to-peak value Ypp, and the peak-to-peak value Zpp is equal to or greater than the corresponding threshold value, there is an imbalance in the rotating barrel 4 that cannot be ignored. Therefore, if any one of the peak-to-peak values pp is equal to or greater than the threshold value (NO in step S18), the control unit 21 determines that there is an imbalance in the degree to which attention should be paid. Then, the control unit 21 confirms whether the rotation speed of the motor 6 at the current time is equal to or greater than a predetermined lower spin speed (step S21). The lower limit spin speed is the lower limit of spin speed, which is 800 rpm in this embodiment. Even if the rotation speed of the motor 6 is lower than the target spin speed, as long as it is higher than the lower limit spin speed, the laundry Q in the rotary tub 4 can be sufficiently dehydrated by extending the main spin period (see FIG. 3 ). If the rotational speed of the motor 6 at the current time is equal to or greater than the lower limit spin speed (YES in step S21), the control unit 21 determines the rotational speed at the current time at which the vibration of the dewatering tub 16 starts to increase as the spin speed, causing the motor 6 to The spin speed rotates steadily and the spin operation continues (step S22), and detection 2 is performed (step S20). However, since the current rotational speed is not limited to a value lower than the target spin speed, it may be a value that has reached the target spin speed.

If the rotation speed of the motor 6 at the current time is lower than the lower limit spin speed (NO in step S21), the control unit 21 adds 1 (+1) to the aforementioned count value i (step S23). If the count value i after adding 1 is smaller than the predetermined value (YES in step S24), the control unit 21 stops the rotation of the motor 6 (step S25). The predetermined value in this embodiment is 2. The control unit 21 stops the spinning operation by stopping the rotation of the motor 6 in step S25. In this case, the control unit 21 performs the restart of the spin-drying operation by repeating the process from step S2 (see FIG. 7 ). Restarting the dehydration operation means that the control unit 21 stops the rotation of the motor 6 and pauses the dehydration operation, and immediately rotates the motor 6 again to restart the dehydration operation. The count value i is the number of restarts of the spin-drying operation. In this embodiment, if a restart of the spin-drying operation has been performed (NO in step S24), the control unit 21 does not perform the next restart and stops the rotation of the motor 6 (step S26). Balance correction (step S27).

In the imbalance correction, the control unit 21 temporarily drains the dehydration tub 16 and supplies water to the dehydration tub 16 to a predetermined water level, so that the laundry Q in the rotary tub 4 is immersed in water and easily spread out. In this state, the control unit 21 rotates the rotary tub 4 and the rotary wing 5 to peel and stir the laundry Q attached to the inner circumferential surface of the rotary tub 4, thereby reducing the laundry in the rotary tub 4 Q's bias is imbalance. In this way, in the dehydration operation, when the restart has been performed once, when the peak-to-peak value pp reaches the threshold value or more again, even if the second restart is performed, the possibility of eliminating the imbalance is very low. Therefore, The dehydration operation is suspended to perform imbalance correction instead of the second restart. After the imbalance correction, the dehydration operation is restarted from the first step S1.

9 is a flowchart showing detection 2. Following the start of detection 2, the control unit 21 acquires the instantaneous rotation speed A of the motor 6 at the current time through the rotation speed sensor 26, and calculates the rotation period T and the sampling period S of the motor 6 (step S31). The sampling period S in Test 2 is the same as that in Test 1, and is a length corresponding to 1.5 cycles. That is, the control unit 21 sets each sampling period S to be longer than the corresponding rotation period T. Then, as in step S12, the control unit 21 resets the timer 24 and the acceleration sensor 27 (step S32), and starts counting the timer 24 (step S33). After the start of time counting, the control unit 21 acquires the detection value of the acceleration sensor 27 in units of 1 millisecond before the measured value t of the timer 24 reaches the sampling period S (step S34).

When the sampling period S has elapsed since the timing in step S33 (YES in step S35), the control section 21 selects from many detection values continuously acquired in units of 1 millisecond during the sampling period S, as in step S16, The maximum value max and the minimum value min in the X-axis direction, the Y-axis direction, and the Z-axis direction are acquired (step S36). Then, as in step S17, the control unit 21 obtains the respective peak-to-peak values pp in the X-axis direction, the Y-axis direction, and the Z-axis direction based on the maximum value max and the minimum value min obtained in step S36, and according to the instant obtained in step S31 The rotation speed A acquires a threshold (step S37).

If the peak-to-peak value Xpp, the peak-to-peak value Ypp, and the peak-to-peak value Zpp obtained in step S37 are smaller than the corresponding threshold values, respectively, the unbalance of the rotary drum 4 rotating at a high speed at the spin speed is small, which is not a problem. In this case (YES in step S38), the control unit 21 takes the new sampling period S as a unit before the above-mentioned formal dehydration period (see FIG. 3) elapses (NO in step S39) The processing of steps S31 to S38 is repeated. That is, in each of the plurality of sampling periods S in which the motor 6 is stably rotating at the spin speed, the control unit 21 acquires the peak-to-peak value pp of the detection value of the acceleration sensor 27 and compares the peak-to-peak value pp with the threshold value. When the formal spin-drying period has elapsed (YES in step S39), the control unit 21 stops the rotation of the motor 6 (step S40), and the detection 2 ends. Thus, a series of dehydration operations are ended.

In the rotary tub 4 which is stably rotating at the spin speed, depending on the situation where water is discharged from the laundry Q, the imbalance may increase. When the unbalance increases, the waveform W of the detected value of the acceleration sensor 27 may increase, and the peak-to-peak value pp may increase (see FIG. 5 ). If at least one of the peak-to-peak value Xpp, the peak-to-peak value Ypp, and the peak-to-peak value Zpp is equal to or greater than the corresponding threshold value, there may be an imbalance that cannot be ignored in the rotary tub 4 rotating at a high speed at the spin speed.

Therefore, if any of the peak-to-peak values pp is equal to or greater than the threshold value (NO in step S38), the control unit 21 adds 1 (+1) to the count value F (step S41). If the count value F after incrementing is smaller than the predetermined value (YES in step S42), the control unit 21 repeats the processing from step S31. The predetermined value in this embodiment is 10. When the count value F after adding 1 reaches 10 (NO in step S42), the control unit 21 determines that there is an imbalance of a predetermined size or more that abnormally vibrates the dewatering tank 16 in the rotating tub 4 (step S43), and stops the motor The rotation of 6 stops the spin-drying operation (step S44), and executes the imbalance correction described above (step S45). After the imbalance correction, perform the spin operation again.

In this way, the abnormal vibration of the dewatering tub 16 due to the imbalance in the stable rotation of the rotating tub 4 at the dehydrating rotation speed can be monitored based on the peak-to-peak value pp of each sampling period S. In particular, each sampling period S is set to be longer than the rotation period T of the rotating tub 4 obtained from the instantaneous rotation speed A of the motor 6 detected by the rotation speed sensor 26. As a result, in each sampling period S, the vibration of the dewatering bucket 16 during the period in which the rotating drum 4 rotates more than one revolution can be detected by the acceleration sensor 27, and therefore, it is effective to determine that there is an imbalance of a predetermined size or more. Peak-to-peak value pp. Furthermore, in the dehydrator 1, when it is determined that there is an imbalance of a predetermined size or more in the rotary tub 4, the rotation of the motor 6 is stopped, and therefore, the processing can be appropriately performed so that it does not continue without removing the abnormal vibration The high-speed rotation of the rotating barrel 4. That is, in the dehydrator 1, it is possible to detect the vibration state of the rotating drum 4 at a dehydration rotation speed to stabilize the rotation of the dehydration drum 16, and to ensure reliable dehydration performance by stopping the dehydration operation according to the deterioration of the vibration state.

FIG. 10 is a timing chart showing the first irregular vibration occurring in the spinning dewatering bucket 16 during the dehydration operation. In the timing chart of FIG. 10, the horizontal axis represents elapsed time (unit: milliseconds), and the vertical axis represents the detection value (unit: mm, for example) of the acceleration sensor 27 in any one of the X-axis direction, the Y-axis direction, and the Z-axis direction. /ms ² ). Regardless of the magnitude of the imbalance, in the continuous waveform of the detection value of the acceleration sensor 27 during the rotation of the rotating barrel 4, in the waveform W of one cycle amount same as the rotation period T, if the minimum value min is used as the starting point, then Generally, after the detection value of the acceleration sensor 27 continuously increases from the minimum value min to the maximum value max, it continuously decreases to the next minimum value min (refer to FIG. 4). Therefore, in the normal waveform W, the increase or decrease in the detection value of the acceleration sensor 27 should be switched only once in the rotation period T.

For example, if the support member 10 that elastically supports the dewatering bucket 16 is aged, the movement of the support member 10 may be caught, and the support member 10 may not move smoothly. Accordingly, in accordance with the engagement, irregularities W3 as shown in FIG. 10 are generated in the middle of each waveform W. Therefore, in each waveform W, the increase or decrease of the detection value of the acceleration sensor 27 is switched within the rotation period T three times. That is, the number r of increase/decrease switching of the detection value in each waveform W is a predetermined number of times (two times in this embodiment) or more. The increase/decrease switching frequency r exists in the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. The number r of increase/decrease switching in the X axis direction is called the number Xr of increase/decrease switching, the number r of increase/decrease switching in the Y axis direction is called the number of increase/decrease switching Yr, and the number r of increase/decrease switching in the Z axis direction is called increase/decrease Switching times Zr. The abnormal vibration that occurs as a result of the waveform W increasing or decreasing the number r of switching times being a predetermined number or more is referred to as first irregular vibration. In the detection 2 of the first modification, the first irregular vibration can be detected early.

FIG. 11 is a flowchart showing detection 2 of the first modification. In FIG. 11, the same processing steps as those in FIG. 9 are assigned the same step numbers as in FIG. 9, and detailed descriptions of the processing steps are omitted. The same applies to FIG. 13 described later. As detection 2 of the first modification starts, the control unit 21 acquires the instantaneous rotation speed A of the motor 6 at the current time, and calculates the rotation period T and the sampling period S of the motor 6 (step S31). As in the previous embodiment, the sampling period S is longer than the rotation period T. Then, the control unit 21 resets the timer 24 and the acceleration sensor 27 (step S32). In the first modification, by this reset, in addition to the measured value t of the timer 24 and the maximum value max and the minimum value min of the detection values of the acceleration sensors 27 in the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively In addition to initialization, the above-mentioned increase and decrease switching times r are also initialized to zero. Then, the control unit 21 starts counting by the timer 24 (step S33), and acquires the detection value of the acceleration sensor 27 in units of 1 millisecond (step S34).

The control unit 21 monitors whether the increase or decrease in the detection value of the acceleration sensor 27 in the X-axis direction, the Y-axis direction, and the Z-axis direction is switched (step S51). Whenever the detection value of the acceleration sensor 27 that has been continuously decreasing so far increases or the detection value of the acceleration sensor 27 that has been continuously increasing so far decreases, the control unit 21 determines that the increase or decrease of the detection value is switched once. Whenever the detection value of the acceleration sensor 27 is switched (YES in step S51), the control unit 21 increases/decreases the number of switching times Xr, increase/decrease switching frequency Yr, and increase/decrease switching frequency Zr. Add 1 (+1) to r (step S52).

If the number r of increase/decrease switching within the rotation period T is less than the above-mentioned predetermined number (two times in this embodiment), the above-mentioned irregularities W3 (see FIG. 10) are not present in the waveform W of the acceleration sensor 27 and stabilize at the spin speed There is no first irregular vibration in the rotating rotating barrel 4. In this case (YES in step S53), the control unit 21 executes the above-mentioned processing after step S35 (refer to FIG. 9), and detects whether or not there is a predetermined size or more when the rotary tub 4 rotates steadily at the spin speed. balance. That is, if there is an imbalance of a predetermined size or more, the control unit 21 executes imbalance correction (step S45). If there is no such imbalance, the control unit 21 ends the spin-drying operation as the formal spin-drying period elapses (YES in step S39).

The control unit 21 repeats the processes of steps S31 to S34 and S51 to S53, and compares the number r of increase/decrease switching within the rotation period T with a predetermined number of times in each of the plurality of sampling periods S until the formal spin period . Then, in any sampling period S, when any one of the increase/decrease switching times Xr, the increase/decrease switching times Yr, and the increase/decrease switching times Zr in the rotation period T is more than a predetermined number of times, that is, when the acceleration sensor 27 When the increase or decrease of the detected value is switched a predetermined number of times or more (NO in step S53), the control unit 21 determines that the first irregular vibration has occurred in the dewatering tank 16 (step S54). In this way, in the dehydrator 1, during the stable rotation of the rotary tub 4, the dehydration tub 16 caused by the deterioration of the support member 10 or the like can be monitored based on the number r of switching times of the increase/decrease in the detection value of the acceleration sensor 27 in the sampling period S. The first irregular vibration. When the control unit 21 determines that the first irregular vibration has occurred, the user is notified of the occurrence of the first irregular vibration through the display of the display operation unit 9 or the alarm of the buzzer (not shown). Furthermore, the control unit 21 may stop the spinning operation by stopping the rotation of the motor 6.

FIG. 12 is a timing chart showing the second irregular vibration occurring in the spinning dewatering tub 16 during the dehydration operation. In the timing chart of FIG. 12, the horizontal axis represents the elapsed time (unit: milliseconds), and the vertical axis represents the detection value of the acceleration sensor 27 in any of the X-axis direction, the Y-axis direction, and the Z-axis direction (unit: for example, mm/ ms ² ). In the continuous waveform of the detection value of the acceleration sensor 27 while the rotating tub 4 is rotating, the maximum value max and the minimum value min of each waveform W are usually constant, and the peak-to-peak value pp is approximately constant (see FIG. 4 ).

It is assumed that during the stable rotation of the rotating tub 4, the water tub 3 constituting the dewatering tub 16 periodically contacts the inner surface of the tank 2 due to some abnormality. Examples of this abnormality include a reduction in the attenuation function of the support member 10 and the like. In addition, a cushion (not shown) is provided at a position where the water tub 3 in the inner surface of the tank 2 can contact. When the water bucket 3 periodically comes into contact with the inner surface portion of the tank 2, as shown in FIG. 12, the maximum value max and the minimum value min of each waveform W periodically increase and decrease respectively, therefore, the maximum value max is connected to each other or the minimum value Min imaginary lines depict a continuous waveform U where irregularities occur repeatedly. In this case, the continuously acquired peak-to-peak value pp does not change substantially constantly, but a periodic increase or decrease occurs more than a predetermined number of times. The abnormal vibration in which the increase or decrease of the peak-to-peak value pp repeatedly occurs a predetermined number of times or more is called second irregular vibration. In detection 2 of the second modification, the second irregular vibration can be detected early.

13 is a flowchart showing detection 2 of the second modification. As detection 2 of the second modification starts, the control unit 21 acquires the instantaneous rotation speed A of the motor 6 at the current time, and calculates the rotation period T and the sampling period S of the motor 6 (step S31). Then, the control unit 21 resets the timer 24 and the acceleration sensor 27 (step S32). By this reset, the measured value t of the timer 24 and the maximum value max and the minimum value min of the detection values of the acceleration sensors 27 in the X-axis direction, the Y-axis direction, and the Z-axis direction are initialized. Then, the control unit 21 starts counting by the timer 24 (step S33), and acquires the detection value of the acceleration sensor 27 in units of 1 millisecond (step S34). When the sampling period S has elapsed (YES in step S35), the control section 21 acquires the maximum value max and the minimum value min of the sampling period S (step S36), and acquires the peak-to-peak value pp and instantaneous values based on these values The threshold value corresponding to the rotation speed A (step S37).

For each peak-to-peak value pp in the X-axis direction, Y-axis direction, and Z-axis direction, the control unit 21 performs the latest peak-to-peak value pp acquired in step S37 and the previous peak-to-peak value pp in the previous sampling period S Compare (step S61). It should be noted that in the first sampling period S after the start of detection 2, there is no previous peak-to-peak value pp. Therefore, the processing in step S61 is obtained for the second and subsequent sampling periods S after the start of detection 2. The peak-to-peak value pp is performed. In this case, the latest peak-to-peak value pp is compared with the previous peak-to-peak value pp temporarily stored in the memory 23. The previous peak-to-peak value pp temporarily stored in the memory 23 is erased from the memory 23 at the time before step S31 when the detection 2 starts.

When the newest peak-to-peak value pp in any of the X-axis direction, Y-axis direction, and Z-axis direction is greater than the corresponding previous peak-to-peak value pp (NO in step S61), the control unit 21 causes The count value V1 whose initial value is zero is increased by 1 (+1) (step S62). It should be noted that the error of the peak-to-peak value pp may also be considered. In this case, when the latest peak-to-peak value pp is greater than the previous peak-to-peak value pp and the difference between the peak-to-peak values pp is greater than the error (step S61 (No in the middle)), the control unit 21 increments the count value V1 by 1 (step S62). The control unit 21 that adds 1 to the count value V1 updates by replacing the previous peak-to-peak value pp with the latest peak-to-peak value pp (step S66), and then executes the processing after step S38 described above (see FIG. 9). During the stable rotation of the rotary drum 4 at the spin speed, the presence or absence of an imbalance of a predetermined size or more is detected. That is, if there is an imbalance of a predetermined size or more, the control unit 21 executes imbalance correction (step S45). If there is no such imbalance, the control unit 21 ends the spin-drying operation as the formal spin-drying period elapses (YES in step S39).

The control unit 21 repeats the processes of steps S31 to S37 and S61 to S66 until the formal dehydration period passes, and in each of the plurality of sampling periods S, performs the latest peak-to-peak value pp and the previous peak-to-peak value pp Compare. Then, when the newest peak-to-peak value pp in each of the X-axis direction, the Y-axis direction, and the Z-axis direction is equal to or less than the corresponding previous peak-to-peak value pp (YES in step S61), the control unit 21 refers to The current count value V1 (step S63). The latest peak-to-peak value pp is less than the previous peak-to-peak value pp and the current count value V1 is 1 or more, which means that the increase or decrease in the peak-to-peak value pp has occurred once. When the count value V1 is zero, it indicates that the peak-to-peak value pp is not increasing or decreasing, but is almost constantly changing (see FIG. 4 ).

If the count value V1 is not zero, that is, if the count value V1 is 1 or more (NO in step S63), the control unit 21 resets the count value V1 to zero of the initial value, and resets the count value of the initial value to zero Add 1 (+1) to V2 (step S64). The count value V2 represents the number of times the peak-to-peak value pp increases or decreases, in other words, the number of concavities or convexities in the continuous waveform U (FIG. 12) described above. The count value V2 is initialized to zero at the time before step S31 when the detection 2 starts. After step S64, the control unit 21 executes the processing after step S38 after updating the previous peak-to-peak value pp (step S66).

When the count value V1 at the time of reference is zero (NO in step S63), the control unit 21 refers to the current count value V2 (step S65). When the count value V2 is smaller than the predetermined value, that is, when the number of times the peak-to-peak value pp is repeatedly increased or decreased is smaller than the predetermined number of times (YES in step S65), the rotary drum 4 that is rotating stably at the spin speed There is no second irregular vibration. Therefore, after updating the previous peak-to-peak value pp (step S66), the control unit 21 executes the processing after step S38.

When the increase or decrease of the peak-to-peak value pp is repeated a predetermined number of times or more (NO in step S65), the control unit 21 determines that the second irregular vibration has occurred in the dewatering tank 16 (step S67). In this way, in the dehydrator 1, during the stable rotation of the rotating tub 4, the second irregular vibration of the dewatering tub 16 caused by some kind of abnormality can be monitored according to the number of repetitions of the increase and decrease of the peak-to-peak value pp. When the control unit 21 determines that the second irregular vibration has occurred, the user is notified of the occurrence of the second irregular vibration through the display of the display operation unit 9 and the alarm of the buzzer (not shown). Furthermore, the control unit 21 may stop the spinning operation by stopping the rotation of the motor 6.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope described in the technical solution.

For example, the detection 2 of the first modification and the detection 2 of the second modification may be performed in combination.

In addition, the rotating tub 4 of the above embodiment is longitudinally arranged so as to be rotatable about the axis J extending in the vertical direction Z, but it may be inclined or horizontal with respect to the vertical direction Z with the axis J as in a drum-type washing machine. The way to configure the rotating barrel 4.

Claims

A dehydrator, characterized in that it includes:

Cabinet

The dehydration bucket, which has a rotating bucket containing laundry and a water bucket containing the rotating bucket, is arranged in the box;

A motor to rotate the rotating barrel;

A supporting member that connects the dewatering barrel to the box body and elastically supports the dewatering barrel;

An acceleration sensor to detect the vibration of the dehydration barrel during the rotation of the rotary barrel;

A motor control unit controls the motor so that the rotation speed of the motor rises to a prescribed spin speed and then rotates steadily at the spin speed to dehydrate the laundry in the rotating tub;

An acquiring unit, acquiring the peak-to-peak value of the detection value of the acceleration sensor during each of the multiple sampling periods in the stable rotation of the motor at the spin speed;

A counting unit, when the peak-to-peak value is above a prescribed threshold, the count value with an initial value of zero is increased by 1; and

The unbalance judgment unit judges that there is an unbalance of a predetermined size or more in the rotating bucket when the count value reaches a predetermined value.
According to the dehydrator of claim 1, when the imbalance judgment unit judges that there is an imbalance of a predetermined size or more in the rotating tub, the motor control unit stops the rotation of the motor.
The dehydrator according to claim 1 or 2, characterized in that

It also includes a speed sensor that detects the speed of the motor,

The acquisition unit sets each of the sampling periods to be longer than the rotation period of the rotating barrel obtained from the rotation speed detected by the rotation speed sensor.
The dehydrator according to any one of claims 1 to 3, further comprising:

The first irregular vibration judging unit judges that the first irregular vibration has occurred in the dehydration bucket when the increase or decrease in the detection value of the acceleration sensor is switched more than a predetermined number of times in any of the sampling periods.
The dehydrator according to any one of claims 1 to 4, further comprising:

The second irregular vibration judging unit judges that the second irregular vibration has occurred in the dehydration barrel when the increase or decrease of the peak-to-peak value is repeated more than a prescribed number of times.