JP6350874B2 - Dehydrator - Google Patents

Description

  The present invention relates to a dehydrator.

  In the following Patent Document 1, a washing machine having a dehydrating function is disclosed. When the laundry is dewatered by the washing machine, the motor that rotates the laundry dewatering tub in which the laundry is stored is rotated at 120 rpm by controlling the duty ratio of the applied voltage. , Steady rotation at 240 rpm, and finally steady rotation at 800 rpm.

  When the dehydration operation is performed in an unbalanced state in which the laundry in the laundry dewatering tub is arranged in the circumferential direction of the laundry dewatering tub, vibration and noise increase. Therefore, in this washing machine, the presence or absence of unevenness of the laundry in the laundry dewatering tub is detected.

  Specifically, the duty ratio at the time when 3.6 seconds have elapsed after the rotation speed of the motor starts to accelerate from 120 rpm to 240 rpm is acquired as the reference duty ratio. In addition, a target value for a duty ratio that changes with time in a state where the motor is normally rotated at 240 rpm is calculated as a comparison duty ratio based on the reference duty ratio. If the difference between the actual duty ratio acquired at each predetermined timing and the comparison duty ratio at the same timing in a state where the motor is normally rotated at 240 rpm and the comparison duty ratio at the same timing is equal to or greater than a predetermined threshold, the laundry is biased. It is determined that there is, and the rotation of the motor is stopped.

JP 2011-240040 A

In the washing machine of Patent Document 1, it is determined that the rotational speed of the motor has reached 240 rpm when 3.6 seconds have elapsed after the rotational speed of the motor starts to accelerate from 120 rpm to 240 rpm, and the duty ratio at this time Is regarded as the reference duty ratio.
However, the time required for the rotation speed of the motor to reach 240 rpm varies depending on the load amount of the laundry in the laundry dewatering tub, and thus is not always constant at 3.6 seconds.

  The reference duty ratio is a factor that affects the detection accuracy of the presence or absence of laundry bias. However, in the case of Patent Document 1, the duty ratio at the time when 3.6 seconds have elapsed from the start of the acceleration of the motor is considered as the reference duty ratio without considering the magnitude of the load amount. Therefore, if the reference duty ratio is a duty ratio acquired at a timing deviated from an appropriate timing due to the influence of the load amount, there is a possibility that the detection accuracy of the presence / absence of laundry bias may be adversely affected.

  In addition, in the case of having a configuration for detecting whether or not there is a bias in the laundry, shortening the time for the dehydration operation is a constantly required problem.

The present invention has been made under such a background, and an object of the present invention is to provide a dehydrator capable of improving the accuracy of detecting whether or not there is a bias in the laundry.
Another object of the present invention is to provide a dehydrator that can shorten the time for dehydration operation.

  The present invention includes a dehydrating tub that stores laundry and rotates to dehydrate the laundry, an electric motor that rotates the dehydrating tub, and the laundry in the dehydrating tub at the start of rotation of the dehydrating tub. A load amount measuring means for measuring the load amount, and after the load amount is measured by the load amount measuring means, the duty ratio of the voltage applied to the motor is controlled so that the motor rotates at a first rotational speed. Drive control means for steady-rotating the motor at a second rotational speed higher than the first rotational speed to dehydrate the laundry in earnest, and the motor up to the first rotational speed. Acquisition means for acquiring a duty ratio of a voltage applied to the motor as a reference duty ratio, and timing for determining the timing at which the acquisition means acquires the reference duty ratio After the acquisition means acquires the reference duty ratio, the duty ratio of the voltage applied to the motor changes from the reference duty ratio in order to maintain the first rotation speed within a predetermined period. If the determination means determines that there is bias in the laundry in the dewatering tub based on the index indicating how the laundry is performed, and the determination means determines that the laundry is biased, the dehydration tub is rotated. Stop control means for stopping, and the timing determination means determines the timing at which the acquisition means acquires the reference duty ratio according to the load amount measured by the load amount measurement means. Machine.

  Further, the present invention provides the rotation of the dehydration tank for restarting the dehydration of the laundry and the bias of the laundry in the dehydration tank when the stop control means stops the rotation of the dehydration tank. And executing means for selecting and executing one of the correction processes according to the index.

  Further, in the present invention, the drive control means causes the motor to rotate at a predetermined speed lower than the first rotation speed before rotating the motor at the first rotation speed. Is characterized in that when the rotation of the dewatering tub for restarting the dehydration of the laundry is executed, the period during which the motor is regularly rotated at the predetermined speed is shortened.

  The present invention also includes a dewatering tub that stores laundry and rotates to dehydrate the laundry, an electric motor that rotates the dewatering tub, and a duty ratio of a voltage applied to the motor. Drive control means for causing the motor to rotate at a first rotation speed and then rotating the motor at a second rotation speed higher than the first rotation speed in order to fully dehydrate laundry. And, after starting the acceleration of the motor toward the first rotation speed, an acquisition means for acquiring the duty ratio at predetermined timings within a predetermined period, and a duty ratio acquired by the acquisition means If it is equal to or greater than the duty ratio acquired immediately before, the count value with an initial value of zero is incremented, and the duty ratio acquired by the acquisition means is the data acquired immediately before. A counting means for resetting the count value to the initial value if it is less than a tea ratio, and a determination means for judging that there is a bias in the laundry in the dewatering tub if the count value is equal to or greater than a predetermined threshold value. The dehydrator further includes stop control means for stopping the rotation of the dewatering tub when the determination means determines that the laundry is biased.

  The present invention also includes a dewatering tub that stores laundry and rotates to dehydrate the laundry, an electric motor that rotates the dewatering tub, and a duty ratio of a voltage applied to the motor. Drive control means for causing the motor to rotate at a first rotation speed and then rotating the motor at a second rotation speed higher than the first rotation speed in order to fully dehydrate laundry. And an acquisition means for acquiring the duty ratio at predetermined timings within a period until the rotation speed of the motor reaches the second rotation speed from the first rotation speed, and the acquisition means acquires If the duty ratio is equal to or greater than a predetermined threshold, the determination means for determining that there is a bias in the laundry in the dewatering tub, and the determination means for determining that there is a bias in the laundry, Stop control means for stopping rotation of the dewatering tub, acceptance means for accepting selection about the dehydration condition of the laundry, and threshold change means for changing the threshold according to the dehydration condition accepted by the acceptance means It is a dehydrator characterized by including.

  The present invention also includes a dewatering tub that stores laundry and rotates to dehydrate the laundry, an electric motor that rotates the dewatering tub, and a duty ratio of a voltage applied to the motor. Drive control means for causing the motor to rotate at a first rotation speed and then rotating the motor at a second rotation speed higher than the first rotation speed in order to fully dehydrate laundry. And an acquisition means for acquiring a maximum value of the duty ratio as a maximum duty ratio in an acceleration state of the motor up to the first rotation speed, and at predetermined intervals after the acquisition means acquires the maximum duty ratio. A calculating means for calculating an integrated value of a difference between the duty ratio and the maximum duty ratio, and if the integrated value is less than a predetermined threshold, the bias of the laundry in the dewatering tub Determination means that there, if the deviation is present between the determination unit of the laundry is determined is a dewatering machine which comprises a stop control means for stopping the rotation of the dewatering tank.

  Further, the present invention is characterized in that the threshold value is obtained from an expression having a count value incremented every predetermined time and the maximum duty ratio as variables.

  In the present invention, the maximum duty ratio is determined when the drive control means has a rotational speed slightly lower than the rotational speed at which the resonance of the dewatering tank occurs in the acceleration state of the motor up to the first rotational speed. The duty ratio is controlled so as to occur.

According to the present invention, as the dehydration operation in the dehydrator, the motor is rotated at the first rotation speed by controlling the duty ratio of the voltage applied to the electric motor that rotates the dehydration tank. The laundry in the dewatering tub is fully dehydrated by rotating the motor at a second rotation speed higher than the first rotation speed.
The reference duty ratio is acquired by the acquisition means in the acceleration state of the motor up to the first rotation speed in relation to the detection of whether the laundry is biased in the dewatering tub. Then, after the acquisition means acquires the reference duty ratio, an index indicating how the duty ratio of the voltage applied to the motor changes from the reference duty ratio in order to maintain the first rotation speed within a predetermined period. Based on this, it is determined whether the laundry is biased in the dewatering tub. When it is determined that there is a bias in the laundry, the rotation of the dewatering tank is stopped.
As part of detecting the presence or absence of such a bias, at the start of rotation of the dewatering tub, the load amount of the laundry in the dewatering tub is measured, and the timing determination means determines whether the acquisition means is the reference according to the measured load amount. The timing for acquiring the duty ratio is determined. Thereby, since the reference duty ratio is acquired at an appropriate timing in consideration of the influence of the load amount, it is possible to accurately detect the presence or absence of the laundry bias based on the reference duty ratio. As a result, it is possible to improve the detection accuracy of the presence or absence of laundry bias.

Further, according to the present invention, when the rotation of the dewatering tub is stopped in response to the determination that the laundry is biased, the rotation of the dewatering tub for restarting the dehydration of the laundry, and the inside of the dewatering tub One of the processes for correcting the bias of the laundry is selected and executed according to an index indicating that the duty ratio changes from the reference duty ratio.
That is, if it is determined that there is a laundry bias, the process of correcting the laundry bias is not performed uniformly. Therefore, if it is an indicator that the bias of the laundry is small, the time for the dehydration operation can be shortened by immediately rotating the dehydration tank and restarting the dehydration.

  Further, according to the present invention, in the dehydration operation including the step of rotating the motor at a predetermined speed lower than the first rotation speed, when the rotation of the dehydration tank for resuming the dehydration of the laundry is executed. Since the period of this process is shortened, the time for the dehydration operation can be further shortened.

Further, according to the present invention, as the dehydration operation in the dehydrator, the motor is steadily rotated at the first rotation speed by controlling the duty ratio of the voltage applied to the electric motor that rotates the dehydration tank, and thereafter Furthermore, the laundry in the dewatering tub is dehydrated in earnest by rotating the motor at a second rotation speed higher than the first rotation speed.
In relation to detection of the presence or absence of laundry bias in the dewatering tank, after starting the acceleration of the motor toward the first rotation speed, the duty ratio is acquired for each predetermined timing within a predetermined period, Each duty ratio is compared with the duty ratio acquired immediately before. Specifically, if the acquired duty ratio is equal to or greater than the duty ratio acquired immediately before, the count value with an initial value of zero is incremented, and the acquired duty ratio is less than the duty ratio acquired immediately before. In this case, the count value is reset to the initial value.
If the count value is equal to or greater than a predetermined threshold value, it is determined that there is a bias in the laundry in the dewatering tub, and the rotation of the dewatering tub is stopped.
In this way, if the configuration constantly monitors the change between the duty ratios adjacent to each other, even if the change from the initial duty ratio acquired at the start of detection is small, the change in the duty ratio in the middle of detection can be detected in real time. Since the captured accurate detection can be performed, it is possible to improve the detection accuracy of the presence or absence of laundry bias.

Further, according to the present invention, as the dehydration operation in the dehydrator, the motor is steadily rotated at the first rotation speed by controlling the duty ratio of the voltage applied to the electric motor that rotates the dehydration tank, and thereafter Furthermore, the laundry in the dewatering tub is dehydrated in earnest by rotating the motor at a second rotation speed higher than the first rotation speed.
In relation to detection of the presence or absence of laundry bias in the dewatering tub, the duty ratio is set at every predetermined timing within a period until the rotational speed of the motor reaches the second rotational speed from the first rotational speed. To be acquired. If this duty ratio is equal to or greater than a predetermined threshold value, it is determined that there is a bias in the laundry in the dewatering tub, and the rotation of the dewatering tub is stopped.
This dehydrator can accept selection about the dehydration condition of the laundry in the accepting means, and can change the threshold according to the accepted dehydration condition. Thereby, in the dehydration operation under each dehydration condition, whether or not the laundry is biased can be detected based on a threshold value suitable for each dehydration condition, so that the detection accuracy of the presence or absence of the laundry bias can be improved.

Further, according to the present invention, as the dehydration operation in the dehydrator, the motor is steadily rotated at the first rotation speed by controlling the duty ratio of the voltage applied to the electric motor that rotates the dehydration tank, and thereafter Furthermore, the laundry in the dewatering tub is dehydrated in earnest by rotating the motor at a second rotation speed higher than the first rotation speed.
In connection with the detection of the presence or absence of laundry bias in the dewatering tub, the maximum value of the duty ratio is acquired as the maximum duty ratio in the acceleration state of the motor up to the first rotation speed. An integrated value of the difference from the duty ratio for each predetermined time is calculated.
If the laundry is not biased in the dewatering tub, after the maximum duty ratio is generated, the motor can be accelerated to the first rotational speed even if the duty ratio is small, so that the duty ratio gradually decreases. As a result, the difference between the duty ratio and the maximum duty ratio gradually increases, so that the integrated value increases. However, if there is a bias in the laundry in the dewatering tank, the duty ratio must be increased after the maximum duty ratio is generated in order for the motor to accelerate to the first rotational speed. The subsequent duty ratio is difficult to decrease. As a result, the difference between the duty ratio and the maximum duty ratio is unlikely to increase, and the integrated value is unlikely to increase.
Therefore, if the integrated value is less than the predetermined threshold, it is determined that there is a bias in the laundry in the dewatering tub, and the rotation of the dewatering tub is stopped.
In this way, if the relative configuration of the duty ratio relative to the maximum duty ratio after the generation of the maximum duty is monitored, the detection accuracy of the presence or absence of the laundry bias can be improved.

  Further, according to the present invention, the threshold value is obtained from an equation having a count value incremented every predetermined time and a maximum duty ratio as variables. The maximum duty ratio varies depending on the load amount of the laundry in the dewatering tub. Therefore, the threshold value is determined so as to be different for each load amount. Thereby, since the presence or absence of the bias | inclination of the laundry is detected based on the optimal threshold value according to the magnitude | size of the load of the laundry in a dehydration tank, a misdetection can be prevented. Therefore, it is possible to further improve the accuracy of detecting whether or not the laundry is biased.

  Further, according to the present invention, the duty ratio is set such that the maximum duty ratio is generated when the rotational speed is slightly lower than the rotational speed at which resonance of the dewatering tank occurs. In this case, resonance occurs at an early timing after the maximum duty ratio is generated. As a result, a phenomenon in which the integrated value is difficult to increase occurs quickly. Therefore, it is possible to detect early and accurately that there is a bias in the laundry in the dewatering tub.

FIG. 1 is a schematic vertical sectional right side view of a dehydrator 1 according to an embodiment of the present invention. FIG. 2 is a block diagram showing an electrical configuration of the dehydrator 1. FIG. 3 is a time chart showing the state of the rotational speed of the motor 6 in the dehydration operation performed by the dehydrator 1. FIG. 4 is a graph showing the relationship between the weight of the laundry stored in the dewatering tub 4 of the dehydrator 1 and the load amount detected by the dehydrator 1 according to the weight of the laundry. FIG. 5A is a flowchart showing an outline of detection 1 to detection 4 for detecting whether or not the laundry is biased in the dehydration tank 4 in the dehydration operation. FIG. 5B is a flowchart showing an outline of detection 1 to detection 4 for detecting whether or not the laundry is biased in the dehydration tank 4 in the dehydration operation. FIG. 6A is a flowchart showing a control operation for detection 1 and detection 2. FIG. 6B is a flowchart showing a control operation for detection 1 and detection 2. FIG. 7 is a graph showing the relationship between the rotation speed of the motor 6 and the difference Sn in the rotation speed in relation to the detection 1. FIG. 8 is a graph showing the relationship between the rotational speed of the motor 6 and the integrated value U for the absolute value of the difference S in relation to the detection 2. FIG. 9A is a flowchart showing the control operation for detection 3 and detection 4. FIG. 9B is a flowchart showing the control operation for detection 3 and detection 4. FIG. 10 is a graph showing the relationship between time and the first count value E in relation to the detection 3. FIG. 11 is a graph showing the relationship between time and the correction duty ratio dn_diff in relation to the detection 4. FIG. 12 is a flowchart showing an outline of detection 5-1 and detection 5-2 for detecting whether or not the laundry is biased in the dehydration tank 4 in the dehydration operation. FIG. 13 is a flowchart showing a control operation for detection 5-1. FIG. 14 is a graph showing the relationship between the rotational speed and the movement integrated value Cn in relation to the detection 5-1 and the detection 5-2. FIG. 15 is a flowchart showing a control operation for detection 5-2. FIG. 16 is a flowchart showing a control operation for detecting bubbles during the dehydration operation. FIG. 17 is a time chart showing the state of the rotational speed of the motor 6 during the dehydration operation performed by the dehydrator 1 in relation to the detection 6. FIG. 18 is a flowchart showing the control operation for the detection 6. FIG. 19 is a graph showing the relationship between the count value G and the integrated value H in relation to the detection 6. FIG. 20 is a graph showing the relationship between the count value G and the duty ratio in relation to the detection 6.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a schematic vertical sectional right side view of a dehydrator 1 according to an embodiment of the present invention.
The vertical direction in FIG. 1 is referred to as the vertical direction X of the dehydrator 1, and the horizontal direction in FIG. 1 is referred to as the front-rear direction Y of the dehydrator 1. Of the vertical direction X, the upper part is referred to as an upper part X1, and the lower part is referred to as a lower part X2. In the front-rear direction Y, the left side in FIG. 1 is referred to as a front Y1, and the right side in FIG. 1 is referred to as a rear Y2.

  The dehydrator 1 includes all devices capable of dehydrating the laundry Q. Therefore, the dehydrator 1 includes not only a device having a dehydrating function but also a washing machine and a washing and drying machine having a dehydrating function. Below, the dehydrator 1 will be described taking a washing machine as an example.

  The dehydrator 1 includes a housing 2, an outer tub 3, a dewatering tub 4, a rotary blade 5, an electric motor 6, and a transmission mechanism 7.

  The housing | casing 2 is metal, for example, and is formed in a box shape. The upper surface 2A of the housing 2 is formed to be inclined with respect to the front-rear direction Y so as to extend upward X1 toward the rear Y2. An opening 8 that allows communication between the inside and outside of the housing 2 is formed in the upper surface 2A. A door 9 for opening and closing the opening 8 is provided on the upper surface 2A. On the upper surface 2A, an operation unit 20 composed of a liquid crystal operation panel or the like is provided in a region Y1 ahead of the opening 8. The user can freely select the dehydrating conditions by operating the operation unit 20, and can instruct the dehydrator 1 to start or stop the operation.

  The outer tub 3 is made of, for example, resin and is formed in a bottomed cylindrical shape. The outer tub 3 has a substantially cylindrical circumferential wall 3A arranged along the vertical direction X, a bottom wall 3B that closes a hollow portion of the circumferential wall 3A from below X2, and an edge on the upper X1 side of the circumferential wall 3A. The ring-shaped annular wall 3 </ b> C projecting toward the circle center side of the circumferential wall 3 </ b> A while being edged. Inside the annular wall 3C, an entrance / exit 10 is formed which communicates with the hollow portion of the circumferential wall 3A from above X1. The doorway 10 is opposed to and communicated with the opening 8 of the housing 2 from the lower X2. A door 11 that opens and closes the entrance 10 is provided on the annular wall 3C. The bottom wall 3B is formed in a disk shape extending substantially horizontally, and a through hole 3D penetrating the bottom wall 3B is formed at a circular center position of the bottom wall 3B.

  Water is stored in the outer tub 3. A water supply path 12 connected to a tap water faucet is connected to the outer tub 3 from the upper side X1, and tap water is supplied from the water supply path 12 into the outer tub 3. In the middle of the water supply path 12, a water supply valve 13 that is opened and closed in order to start and stop water supply is provided. A drainage channel 14 is connected to the outer tub 3 from below X2, and water in the outer tub 3 is discharged from the drainage channel 14 to the outside of the machine. In the middle of the drainage channel 14, a drainage valve 15 that is opened and closed to start and stop drainage is provided.

  The dewatering tub 4 is made of, for example, metal, is formed in a bottomed cylindrical shape that is slightly smaller than the outer tub 3, and can store the laundry Q therein. The dewatering tank 4 has a substantially cylindrical circumferential wall 4A disposed along the vertical direction X, and a bottom wall 4B that closes a hollow portion of the circumferential wall 4A from below X2.

  An inner peripheral surface of the circumferential wall 4 </ b> A is an inner peripheral surface of the dewatering tank 4. The upper end portion of the inner peripheral surface of the circumferential wall 4A is an entrance / exit 21 that exposes the hollow portion of the circumferential wall 4A to the upper side X1. The entrance / exit 21 is opposed to and communicated with the entrance / exit 10 of the outer tub 3 from below X2. The doorways 10 and 21 are collectively opened and closed by the door 11. The user of the dehydrator 1 puts the laundry Q in and out of the dehydration tank 4 through the opened opening 8 and the entrances 10 and 21.

  The dewatering tank 4 is accommodated coaxially in the outer tank 3. The dehydration tank 4 accommodated in the outer tub 3 is rotatable about an axis 16 that extends in the vertical direction X with its central axis. Further, a plurality of through holes (not shown) are formed in the circumferential wall 4A and the bottom wall 4B of the dehydrating tank 4, and water in the outer tank 3 passes between the outer tank 3 and the dehydrating tank 4 via the through holes. You can go back and forth. Therefore, the water level in the outer tub 3 matches the water level in the dehydration tub 4.

  The bottom wall 4B of the dewatering tub 4 is formed in a disk shape extending substantially parallel to the bottom wall 3B of the outer tub 3 with an interval X1 above the bottom wall 3B. The through-hole 4C that penetrates the bottom wall 4B is formed. The bottom wall 4B is provided with a tubular support shaft 17 that extends downward X2 along the axis 16 while surrounding the through hole 4C. The support shaft 17 is inserted into the through hole 3D of the bottom wall 3B of the outer tub 3, and the lower end portion of the support shaft 17 is located below the bottom wall 3B in the X2.

  The rotary blade 5 is a so-called pulsator, is formed in a disk shape with the axis 16 as the center of the circle, and is disposed concentrically with the dehydration tank 4 along the bottom wall 4 </ b> B in the dehydration tank 4. A plurality of blades 5 </ b> A arranged radially are provided on the upper surface of the rotary blade 5 that faces the entrance / exit 21 of the dewatering tank 4. The rotary blade 5 is provided with a rotary shaft 18 that extends downward X2 along the axis 16 from the center of the circle. The rotating shaft 18 is inserted into the hollow portion of the support shaft 17, and the lower end portion of the rotating shaft 18 is located below the bottom wall 3 </ b> B of the outer tub 3.

  In the present embodiment, the motor 6 is realized by an inverter motor. The motor 6 is disposed below the outer tub 3 in the housing 2. The motor 6 has an output shaft 19 that rotates about an axis 16. The transmission mechanism 7 is interposed between the lower end portions of the support shaft 17 and the rotary shaft 18 and the upper end portion of the output shaft 19. The transmission mechanism 7 selectively transmits the driving force output from the output shaft 19 by the motor 6 to one or both of the support shaft 17 and the rotation shaft 18. A known transmission mechanism 7 is used.

  When the driving force from the motor 6 is transmitted to the support shaft 17 and the rotary shaft 18, the dewatering tank 4 and the rotary blade 5 rotate around the axis 16. In the washing operation and the rinsing operation, the laundry Q in the dewatering tank 4 is agitated by the rotating dewatering tank 4 and the blades 5A of the rotary blades 5. In the dehydration operation after the rinsing operation, the laundry Q in the dehydration tub 4 is dehydrated by the high-speed rotation of the dehydration tub 4 and the rotary blade 5 together.

FIG. 2 is a block diagram showing an electrical configuration of the dehydrator 1.
Referring to FIG. 2, the dehydrator 1 includes a load amount measuring unit, a drive control unit, an acquisition unit, a timing determination unit, a determination unit, a stop control unit, an execution unit, a count unit, a reception unit, a threshold change unit, and a calculation unit. The control part 30 is included. The control unit 30 is configured as a microcomputer including, for example, a CPU 31, a memory 32 such as a ROM or a RAM, a timer 35, and a counter 36, and is built in the housing 2 (see FIG. 1).

  The dehydrator 1 further includes a water level sensor 33 and a rotation speed reading device 34. The water level sensor 33, the rotation speed reading device 34, and the motor 6, the transmission mechanism 7, the water supply valve 13, the drain valve 15 and the operation unit 20 are electrically connected to the control unit 30.

  The water level sensor 33 is a sensor that detects the water level of the outer tub 3 and the dehydration tub 4, and the detection result of the water level sensor 33 is input to the control unit 30 in real time.

  The rotation speed reading device 34 is a device that reads the rotation speed of the motor 6, strictly speaking, the rotation speed of the output shaft 19 of the motor 6, and is constituted by, for example, a Hall IC. The rotational speed read by the rotational speed reading device 34 is input to the control unit 30 in real time. The control unit 30 rotates the motor 6 at a desired number of revolutions by controlling the duty ratio of the voltage applied to the motor 6 based on the inputted number of revolutions.

  The control unit 30 switches the transmission destination of the driving force of the motor 6 to one or both of the support shaft 17 and the rotation shaft 18 by controlling the transmission mechanism 7. The control unit 30 controls opening and closing of the water supply valve 13 and the drain valve 15. As described above, when the user operates the operation unit 20 to select the dehydration condition of the laundry Q, the control unit 30 receives the selection.

Next, the dehydration operation performed in the dehydrator 1 will be described.
FIG. 3 is a time chart showing the state of the rotational speed of the motor 6 in the dehydration operation performed by the dehydrator 1. In the time chart of FIG. 3, the horizontal axis indicates the elapsed time, and the vertical axis indicates the rotation speed (unit: rpm) of the motor 6.

  With reference to FIG. 3, in the dehydrating operation, the control unit 30 measures the load amount of the laundry Q in the dehydrating tub 4 at the start of rotation of the dehydrating tub 4. After measuring the load amount, the control unit 30 increases the rotational speed of the motor 6 to a predetermined speed of 120 rpm and then rotates the motor 6 at 120 rpm. Thereafter, the control unit 30 raises the motor 6 from 120 rpm to a first rotation speed of 240 rpm, and then rotates the motor 6 at 240 rpm. Thereafter, the control unit 30 raises the motor 6 from 240 rpm to a second rotation speed of 800 rpm and then rotates the motor 6 at 800 rpm. By the steady rotation of the motor 6 at 800 rpm, the laundry Q in the dewatering tub 4 is fully dewatered. During the dehydration operation, when the rotation speed of the motor 6 is, for example, 50 rpm to 60 rpm, lateral resonance occurs in the dehydration tank 4, and when the rotation speed of the motor 6 is, for example, 200 rpm to 220 rpm, Resonance occurs.

  When the laundry Q in the dewatering tub 4 is in a state of being biased in the circumferential direction of the dewatering tub 4, the laundry Q is biased in the dewatering tub 4. When the dehydrating operation is performed in this state, the dehydrating tank 4 is eccentrically rotated, so that the dehydrating tank 4 is greatly shaken to give a large vibration to the dehydrator 1 and noise may be generated.

  Then, the control part 30 detects the presence or absence of the bias | inclination of the laundry Q in the dewatering tank 4 in the middle of the spin-drying | dehydration operation, and will stop the motor 6, if it detects that there exists a bias | inclination. As such detection, the control unit 30 performs five types of electrical detections of detection 1, detection 2, detection 3, detection 4, and detection 5.

  Detection 1 to Detection 4 are low-speed eccentricity detection configured by an acceleration period until the degree of rotation of the motor 6 increases from 120 rpm to 240 rpm and a predetermined period after the acceleration of the motor 6 is started toward 240 rpm. It is executed in the interval. The detection 5 is performed in the high-speed eccentricity detection section which is a period until the rotational speed of the motor 6 reaches from 800 rpm to 800 rpm.

  FIG. 4 is a graph showing the relationship between the weight of the laundry Q accommodated in the dehydrating tub 4 and the load amount detected by the dehydrator 1 according to the weight of the laundry Q. In the graph of FIG. 4, the horizontal axis represents the weight (unit: kg) of the laundry Q, and the vertical axis represents the load amount detection value.

  Referring to FIG. 4, as described above, the control unit 30 measures the load amount of the laundry Q in the dewatering tub 4 at the start of rotation of the dewatering tub 4. The control unit 30 rotates the dehydration tank 4 at a predetermined number of revolutions at the start of rotation of the dehydration tank 4, and detects a value obtained by integrating a certain number of duty ratios of the voltage applied to the motor 6 at that time as a load amount. When the laundry Q becomes heavier, a high voltage must be applied to the motor 6 in order to rotate the dewatering tub 4, so that the load increases as the voltage increases. Thus, the control unit 30 electrically measures the load amount of the laundry Q.

5A and 5B are flowcharts showing an outline of detection 1 to detection 4.
Referring to FIGS. 5A and 5B, when the dehydration rotation of dehydration tank 4 is started by the start of the dehydration operation (step S1), control unit 30 loads load of laundry Q in dehydration tank 4 as described above. The amount is measured (step S2), and then the motor 6 is rotated at 120 rpm for a predetermined time (step S3).

  Thereafter, the control unit 30 starts acceleration of the motor 6 to 240 rpm (step S4), and performs the detection 1 described above during the acceleration period of the motor 6 (step S5). If the detection 1 is not OK (NO in step S5), that is, if the control unit 30 determines that the laundry Q is biased, the control unit 30 stops the motor 6 and dewaters the dehydration tub. 4 is stopped (step S6), and then it is determined whether the dehydration operation can be restarted (step S7).

  The restarting of the dehydration operation means that the control unit 30 rotates the dehydration tank 4 again to resume the dehydration operation immediately after stopping the rotation of the dehydration tank 4 and stopping the dehydration operation. Although details will be described later, depending on the degree of bias of the laundry Q, it may be possible to restart the laundry.

  If the re-startup has not been performed before the re-startup (YES in step S7), the control unit 30 executes the re-startup (step S8). In the re-start-up dehydration operation, the control unit 30 shortens the 120 rpm steady rotation period shorter than the 120 rpm steady rotation period in the dehydration operation stopped immediately before. In the case of restarting, the laundry Q sticks to the inner peripheral surface of the dewatering tub 4 to some extent and the water is almost removed, so the period of steady rotation at 120 rpm may be shortened. Thereby, the time of dehydration operation can be shortened. Such a period reduction is also executed in each subsequent restart.

  If re-startup is impossible (NO in step S7), the control unit 30 executes a process called unbalance correction (step S9). In the unbalance correction, the control unit 30 closes the drain valve 15 and then opens the water supply valve 13 to supply water into the dehydration tank 4 to a predetermined water level, so that the laundry Q in the dehydration tank 4 is immersed in water. Make it easy to unravel. In this state, the control unit 30 rotates and rotates the dewatering tub 4 and the rotor blades 5 to peel and agitate the laundry Q attached to the inner peripheral surface of the dewatering tub 4, thereby washing the laundry in the dehydration tub 4. Correct the bias of Q.

  On the other hand, when the detection 1 is OK (YES in step S5), that is, when the control unit 30 determines in the detection 1 that there is no bias of the laundry Q, the control unit 30 determines that the motor 6 In the acceleration period, the above-described detection 2 is subsequently performed (step S10).

  If the detection 2 is not OK (NO in step S10), that is, if the control unit 30 determines that the laundry Q is biased, the control unit 30 stops the motor 6 and the dewatering tub 4. The dehydration operation is stopped (step S11). Thereafter, the control unit 30 confirms whether the dehydration condition of the dehydration operation that has been stopped this time is “blanket course” or “only dehydration operation” (step S12).

  The blanket course is a dehydrating condition for dehydrating the laundry Q that easily absorbs water such as a blanket. If the dehydration condition is a blanket course (YES in step S12), and before the re-startup in which re-startup has not been performed for the dewatering operation stopped this time (YES in step S13), the control unit 30 Performs a re-startup with a shortened period of 120 rpm steady rotation (step S14).

  In the case of a blanket course, the control unit 30 may erroneously determine that the detection 2 is not OK because a large amount of water that has oozed out of the blanket and accumulated in the outer tub 3 becomes resistance to rotation of the dehydration tub 4. And if imbalance correction is performed in spite of a misjudgment and a blanket absorbs a lot of water again, there exists a possibility that a misjudgment may be made again in the subsequent detection 2. FIG. Therefore, when it is determined that the detection 2 is not OK in the blanket course, if the re-startup is not performed (YES in step S13), the unbalance correction is not performed and the re-startup is performed (step S14). On the other hand, if it is not before re-startup, that is, if re-start-up has been performed with respect to the dehydration operation stopped this time (NO in step S13), the control unit 30 executes unbalance correction (step S15).

  The dehydration only operation is not a dehydration transfer that is performed following the washing operation and the rinsing operation, but is a dehydration condition in which the rinsed laundry Q is put into the dehydration tub 4 and the laundry Q is dehydrated. If the dehydration condition is the operation only for dehydration (YES in step S12) and before the re-startup (YES in step S13), the control unit 30 executes the re-startup (step S14).

  In the case of only dehydration operation, if the rinsed laundry Q gets wet by the imbalance correction, the meaning of preparing the rinsed laundry Q in advance is lost. Therefore, when it is determined that the detection 2 is not OK in the operation only for dehydration, if the re-startup is not performed, the re-startup is performed without correcting the imbalance. The control unit 30 may notify the user to reset the laundry Q in the dehydrating tub 4 by notifying an error through a display on the operation unit 20 or a buzzer. On the other hand, if it is not before restart (NO in step S13), the control unit 30 executes unbalance correction (step S15).

  On the other hand, when the dehydration condition is neither blanket course nor dehydration only (NO in step S12), the control unit 30 is before re-startup regarding the dehydration operation stopped this time, and from now on It is determined whether it is possible (step S16). If it is before re-starting and re-starting is possible (YES in step S16), the control unit 30 executes re-starting with a shortened period of steady rotation of 120 rpm (step S17). If the condition that the restart is possible before the restart is not satisfied (NO in step S16), the control unit 30 executes the unbalance correction (step S18).

  If the detection 2 is OK (YES in step S10), that is, if the control unit 30 determines in the detection 2 that there is no bias of the laundry Q, the control unit 30 uses the timer 35. It is confirmed whether or not the value has become equal to or greater than the set value for each load (step S19). That is, the control unit 30 confirms whether or not the measurement time of the timer 35 has reached the set value corresponding to the load amount of the laundry Q in the dewatering tub 4 in step S19. The setting value will be described in detail later.

  If the value of the timer 35 is equal to or greater than the set value for each load amount (YES in step S19), the control unit 30 performs the detection 3 and the detection 4 described above in a state where the motor 6 is continuously rotated at 240 rpm (step S19) S20). If the detection 3 and the detection 4 are not OK (NO in step S20), that is, if the control unit 30 determines that the laundry Q is biased, the control unit 30 determines that the motor 6 and the dehydration tank 4 Is stopped to stop the dehydration operation (step S11), and the corresponding processing is executed in steps S12 to S18.

  On the other hand, if the detection 3 and the detection 4 are OK (YES in step S20), that is, if the control unit 30 determines in the detection 3 or the detection 4 that there is no bias of the laundry Q, the control is performed. The unit 30 continuously rotates the motor 6 at 240 rpm and continues dehydration at 240 rpm (step S21).

Next, each of detection 1 to detection 4 will be described in detail.
6A and 6B are flowcharts showing control operations for detection 1 and detection 2. FIG. First, detection 1 and detection 2 will be described with reference to FIGS. 6A and 6B. Detection 1 and detection 2 are detection of the presence or absence of the bias of the laundry Q using the rotational speed of the motor 6.

  In step S4 described above, the control unit 30 starts acceleration of the motor 6 to 240 rpm, and starts detection 1 and detection 2. First, the control unit 30 starts the time measurement by starting the timer 35, and measures the rotation speed V0 of the motor 6 at the start of acceleration by the rotation speed reading device 34 (step S31). The rotation speed V0 is around 120 rpm.

  Regarding the value of the timer 35, that is, the measurement time, the acceleration period of the motor 6 to 240 rpm which is the detection time of the detection 1 and the detection 2 is different for each load amount. This is because as the amount of the laundry Q increases, it takes time until the rotational speed of the motor 6 reaches 240 rpm. Therefore, a set value for each load amount for the acceleration period of the motor 6 is obtained in advance by an experiment or the like and stored in the memory 32.

  Then, the control unit 30 starts counting by the counter 36 (step S32), and counts every 0.3 seconds by initializing the counter 36 every time 0.3 seconds elapse (steps S33 and S30). S34).

  Each time the controller 30 counts, the controller 30 measures the rotation speed Vn (n: count value) of the motor 6 at the time of counting (step S35). In step S35, the control unit 30 calculates a difference Sn between the measured rotational speed Vn and the rotational speed Vn-1 measured immediately before Vn. Further, in step S35, the control unit 30 also calculates the integrated value U for the absolute value of the difference between the difference Sn and the immediately preceding difference Sn-1.

  Next, the control unit 30 determines whether the value of the timer 35 is equal to or greater than the set value for each load amount, that is, the measurement time of the timer 35 reaches the set value corresponding to the load amount of the laundry Q in the dewatering tub 4. It is confirmed whether it has been done (step S36). Step S36 corresponds to the above-described step S19 (see FIG. 5A).

  When the value of the timer 35 is less than the set value for each load amount, that is, when the measurement time of the timer 35 does not reach the corresponding set value (NO in step S36), the load of the laundry Q in the dewatering tub 4 If the amount is equal to or smaller than the predetermined amount (YES in step S37), the control unit 30 determines whether or not the difference Sn calculated previously is caught by the detection 1 (step S38). This fixed amount is obtained in advance through experiments or the like and stored in the memory 32.

  Specifically, a threshold value is determined in advance and stored in the memory 32 for the difference Sn. FIG. 7 is a graph showing the relationship between the rotation speed of the motor 6 and the difference Sn in relation to the detection 1. In the graph of FIG. 7, the horizontal axis represents the rotation speed (unit: rpm), and the vertical axis represents the difference Sn (unit: rpm).

  Referring to the rotation speed range indicated by the broken-line arrow in FIG. 7, when the eccentricity is small and the laundry Q can be regarded as having no bias, the acceleration of the dewatering tub 4 is stabilized, so the difference as shown by the solid line The variation of Sn is small. However, when the eccentricity is large and the laundry Q can be regarded as biased, the acceleration of the dewatering tub 4 is not stable. Therefore, as shown by the broken line, the variation of the difference Sn is large, and the minimum value of the difference Sn is below the threshold value. . Therefore, returning to FIG. 6A, if the difference Sn is equal to or smaller than the threshold value, the control unit 30 determines that the difference Sn is caught by the detection 1 (YES in step S38). Thus, in the detection 1, the instability of acceleration of the dewatering tank 4 indicating the presence or absence of the bias of the laundry Q is detected based on the difference Sn.

  If the control unit 30 determines that the difference Sn is caught by the detection 1 (YES in step S38), the control unit 30 stops the rotation of the motor 6 (step S6 described above), and the corresponding process among the steps S7 to S9 described above (FIG. 5A). ). The processing of step S31 to step S38 is included in step S5 (see FIG. 5A) described above.

  If the control unit 30 determines that the detection Sn is not caught due to the difference Sn exceeding the threshold value (NO in step S38), the control unit 30 determines whether the previously calculated integrated value U is caught by the detection 2 (step S39).

  If the load amount of the laundry Q in the dewatering tub 4 exceeds a certain amount (NO in step S37), the control unit 30 does not execute the determination in the detection 1 in step S38, but detects the detection 2 in step S39. Execute the judgment at. This is because when the amount of the laundry Q exceeds a certain amount, the amount of water that oozes out from the laundry Q is large, or the laundry Q suddenly sticks to the inner peripheral surface of the dewatering tub 4. This is because there is a possibility that the detection 1 cannot be stably performed due to a sudden change in the bias of the laundry Q. Therefore, when the amount of the laundry Q exceeds a certain amount, the detection 1 is omitted.

  Regarding determination of whether or not the integrated value U is caught by the detection 2, a threshold value is determined in advance for the integrated value U and stored in the memory 32. FIG. 8 is a graph showing the relationship between the rotational speed of the motor 6 and the integrated value U in relation to the detection 2. In the graph of FIG. 8, the horizontal axis indicates time (unit: sec), and the vertical axis indicates the integrated value U (unit: rpm). Referring to FIG. 8, two types of threshold values are set for the threshold value: a lower threshold value indicated by square dots and an upper threshold value indicated by triangular dots. The upper threshold value is higher than the lower threshold value.

  When the eccentricity is small and the laundry Q is not biased, the acceleration of the dewatering tub 4 is stabilized. Therefore, as shown by the solid line, the integrated value U is lower than the lower threshold value at any timing. However, when the eccentricity is large and the laundry Q is biased, the acceleration of the dewatering tub 4 is not stable, and as shown by the broken line, the integrated value U exceeds the lower threshold value at any timing. If the bias of the laundry Q is large, the integrated value U exceeds the upper threshold value. Therefore, returning to FIG. 6A, if the integrated value U is equal to or greater than the lower threshold value, the control unit 30 determines that the integrated value U is caught by the detection 2 (YES in step S39). Thus, in the detection 2, the instability of acceleration of the dewatering tub 4 indicating the presence or absence of the laundry Q is detected based on the integrated value U.

  When the control unit 30 determines that the integrated value U is caught by the detection 2 (YES in step S39), the control unit 30 stops the rotation of the motor 6 (step S11 described above), and executes the corresponding processing among the steps S12 to S18 described above. To do. The processes of steps S31 to S37 and step S39 are included in the above-described step S10 (see FIG. 5A).

  When the dehydration condition is neither blanket course nor dehydration only (NO in step S12), the control unit 30 has a large bias in the laundry Q to the extent that the integrated value U is equal to or greater than the upper threshold value in step S16. Whether or not the dehydration operation stopped this time has been restarted.

  When the integrated value U is equal to or higher than the upper threshold value or when it has been restarted (YES in step S16), the control unit 30 executes unbalance correction (step S18). If the integrated value U is less than the upper threshold value and has not been restarted (NO in step S16), the control unit 30 executes the restart (step S17). The determination as to whether or not the integrated value U is equal to or greater than the upper threshold corresponds to the determination as to whether or not the restart can be performed in step S16 in FIG. 5B, and the determination as to whether or not the restart has been performed depends on the determination in step S16 in FIG. This is equivalent to determining whether it is before start-up.

  Thus, in steps S16 to S18, the control unit 30 determines whether the bias caught in the detection 2 is small enough to continue to restart or large enough to require unbalance correction. Is determined based on whether or not is equal to or greater than the upper threshold value, and re-startup and unbalance correction are selected and executed according to the magnitude of the bias.

  When it is determined that there is no bias in the laundry Q in both detection 1 and detection 2, when the value of the timer 35 reaches the set value for each load amount (YES in step S36), the control unit 30 Then, detection 1 and detection 2 are ended (step S40). In step S40, the control unit 30 acquires the duty ratio of the voltage applied to the motor 6 when the value of the timer 35 reaches the set value as the reference duty ratio d0. When the value of the timer 35 reaches the set value and the process of step S40 is executed, the motor 6 is in an acceleration state up to 240 rpm.

  As described above, the set value in step S36 differs for each load amount of the laundry Q in the dewatering tub 4. Therefore, the control unit 30 determines the timing for acquiring the reference duty ratio d0 in step S40 according to the load amount measured during the dehydrating rotation of the dehydrating tank 4. In other words, the control unit 30 changes the timing at which the detection 1 and the detection 2 are ended and the subsequent detection 3 and the detection 4 are started according to the load amount. Therefore, the detection 3 and the detection 4 can be executed at an optimal timing according to the amount of the laundry Q.

  9A and 9B are flowcharts showing control operations for detection 3 and detection 4. Detection 3 and detection 4 will be described with reference to FIGS. 9A and 9B. Detection 3 and detection 4 are detection of the presence or absence of the bias of the laundry Q using the duty ratio of the voltage applied to the motor 6.

  In step S40 described above, the control unit 30 acquires the reference duty ratio d0 and starts detection 3 and detection 4. When the detection 3 and the detection 4 are started, the rotation speed of the motor 6 is in a state of reaching 240 rpm, and the motor 6 is normally rotated at 240 rpm.

  In relation to detection 3 and detection 4, a first count value E and a second count value T exist and are stored in the memory 32. At the start of detection 3 and detection 4, the control unit 30 clears each of the first count value E and the second count value T to an initial value of 0 (zero) (step S41).

  And the control part 30 starts the timer 35, starts time measurement (step S42), and monitors whether the value of the timer 35 exceeds 8.1 second. The third detection and the fourth detection are executed within a predetermined period of 8.1 seconds after the reference duty ratio d0 is acquired.

  Further, the control unit 30 starts counting by the counter 36 in step S42, and counts every 0.3 seconds by initializing the counter 36 every time 0.3 seconds elapse (steps S43 and S44). ). The control unit 30 increments (+1) the second count value T at the timing of initializing the counter 36 in step S44, that is, at the timing for each count.

  The control unit 30 acquires the duty ratio dn (n: count value) of the voltage applied to the motor 6 at the time of counting every time it counts (step S45). That is, the control unit 30 acquires the duty ratio dn at every predetermined timing of 0.3 seconds within the above-described predetermined period of 8.1 seconds.

Moreover, the control part 30 calculates the correction | amendment duty ratio dn_diff for every 0.3 second timing based on the following formula | equation (1) and (2) in step S45. The corrected duty ratio dn_diff is a value obtained by correcting the duty ratio dn acquired at the same timing so that detection by the detection 4 can be performed with high accuracy. In addition, A and B in the formulas (1) and (2) are constants obtained by experiments or the like.
dn_diff = A · dn−dn_x Equation (1)
dn_x = (A · d0) − (B · T) (2)

  Next, if the acquired duty ratio dn is greater than or equal to the acquired duty ratio dn-1 at the immediately preceding timing (YES in step S46), the control unit 30 increments (+1) the first count value E (step S47). ). Incidentally, in the third detection, the duty ratio dn first acquired by the control unit 30 is the reference duty ratio d0 described above. On the other hand, if the acquired duty ratio dn is less than the duty ratio dn−1 acquired at the immediately preceding timing (NO in step S46), the control unit 30 sets the first count value E to the initial value 0 (zero). Reset (step S48).

  And the control part 30 confirms whether the value of the timer 35 is 8.1 second or less, ie, whether the measurement time of the timer 35 exceeded 8.1 second (step S49).

  When the value of the timer 35 is 8.1 seconds or less (YES in step S49), if the load amount of the laundry Q in the dewatering tub 4 is equal to or greater than a certain amount (YES in step S50), the control unit 30 Then, it is determined whether or not the latest first count value E is caught by the detection 3 (step S51). This fixed amount is obtained in advance through experiments or the like and stored in the memory 32.

  Specifically, a threshold value is determined in advance for the first count value E and stored in the memory 32. FIG. 10 is a graph showing the relationship between time and the first count value E in relation to the detection 3. In the graph of FIG. 10, the horizontal axis represents time (unit: sec), and the vertical axis represents the first count value E. Referring to FIG. 10, two types of threshold values are set for the threshold value: a lower threshold value indicated by a one-dot chain line and an upper threshold value indicated by a two-dot chain line. Each of the upper threshold value and the lower threshold value is a constant value regardless of the elapsed time. The upper threshold value is higher than the lower threshold value.

  When the eccentricity is small and there is no unevenness of the laundry Q, the motor 6 can rotate at a constant speed of 240 rpm even with a small voltage, so that the duty ratio dn gradually decreases. As a result, the first count value E is stabilized in the vicinity of the initial value 0 (zero), as shown by the solid line.

  However, when the eccentricity is large and the laundry Q is biased, a high voltage is required to maintain the rotational speed of the motor 6 at 240 rpm, so the duty ratio dn does not decrease. As a result, the first count value E increases without returning to the initial value, and exceeds the lower threshold value at any timing as indicated by a broken line. If the bias of the laundry Q is large, the first count value E exceeds the upper threshold value.

  9A, if the latest first count value E is equal to or greater than the lower threshold value, the control unit 30 determines that the first count value E is caught by the detection 3 (YES in step S51). That is, if the first count value E within the predetermined period of 8.1 seconds described above is equal to or greater than the predetermined threshold, the control unit 30 determines that the laundry Q is biased in the dewatering tub 4.

  If the configuration is such that the change between the duty ratios dn adjacent to each other as in the detection 3 is constantly monitored, even if the change from the reference duty ratio d0 that is the first duty ratio dn acquired at the start of detection is small, It is possible to accurately detect changes in the duty ratio dn during detection in real time. Therefore, it is possible to improve the accuracy of detecting whether or not the laundry Q is biased.

  If the control unit 30 determines that the detection 3 is not caught by the first count value E being below the lower threshold (NO in step S51), the control unit 30 determines whether or not the previously calculated corrected duty ratio dn_diff is caught by the detection 4. Determination is made (step S52).

  If the load amount of the laundry Q in the dewatering tub 4 is less than a certain amount (NO in step S50), the control unit 30 does not execute the determination in detection 3 in step S51, but detects in step S52. The determination at 4 is executed. This is because if the detection 3 is performed when the amount of the laundry Q is less than a certain amount, the first count value E becomes unstable because the duty ratio dn converges at an early stage, and the detection 3 is detected. This is because there is a possibility that it cannot be executed stably. Therefore, when the amount of the laundry Q is below a certain amount, the detection 3 is omitted.

  Regarding the determination of whether or not the correction duty ratio dn_diff is caught by the detection 4, a threshold value is determined in advance for the correction duty ratio dn_diff and stored in the memory 32. FIG. 11 is a graph showing the relationship between time and the correction duty ratio dn_diff in relation to the detection 4. In the graph of FIG. 11, the horizontal axis indicates time (unit: sec), and the vertical axis indicates the correction duty ratio dn_diff. Referring to FIG. 11, two types of threshold values are set for the threshold value: a lower threshold value indicated by a one-dot chain line and an upper threshold value indicated by a two-dot chain line. Each of the upper threshold value and the lower threshold value gradually increases according to the elapsed time. The upper threshold value is higher than the lower threshold value.

  When the eccentricity is small and the laundry Q is not biased, the motor 6 can rotate at 240 rpm even with a small voltage, so that the correction duty ratio dn_diff gradually decreases while falling below the lower threshold as shown by the solid line. .

  However, when the eccentricity is large and the laundry Q is biased, a high voltage is required to maintain the rotational speed of the motor 6 at 240 rpm, so the correction duty ratio dn_diff decreases as shown by the broken line. Without exceeding the lower threshold. If the bias of the laundry Q is large, the correction duty ratio dn_diff exceeds the upper threshold value. Therefore, returning to FIG. 9A, if the correction duty ratio dn_diff is equal to or greater than the lower threshold value, the control unit 30 determines that the correction duty ratio dn_diff is caught by the detection 4 (YES in step S52).

  It should be noted that the correction duty ratio dn_diff obtained by the above-described equations (1) and (2) is increased with time when the duty ratio dn is equal to or larger than the reference duty ratio d0. It is a set value. Therefore, the correction duty ratio dn_diff is not caught on the threshold value only when the duty ratio dn is normally lowered from the reference duty ratio d0.

  As described above, the first count value E used for the detection 3 and the correction duty ratio dn_diff used for the detection 4 are supplied to the motor 6 in order to maintain 240 rpm within the predetermined period of 8.1 seconds described above. It is an index showing how the duty ratio dn of the applied voltage changes from the reference duty ratio d0. In the detection 3 and the detection 4, the control unit 30 determines whether or not the laundry Q is biased in the dewatering tub 4 based on such an index.

  Further, since the first count value E used for the detection 3 and the correction duty ratio dn_diff used for the detection 4 are obtained based on the reference duty ratio d0, the reference duty ratio d0 is the presence or absence of the bias of the laundry Q. This is a factor that affects the detection accuracy. In the dehydrator 1, as described above, the control unit 30 measures the load amount of the laundry Q in the dewatering tub 4 at the start of rotation of the dewatering tub 4 (step S2 in FIG. 5A). Accordingly, the timing for acquiring the reference duty ratio d0 is determined (step S36 in FIG. 6A). As a result, the reference duty ratio d0 is acquired at an appropriate timing in consideration of the influence of the load amount. Based on the reference duty ratio d0, the detection 3 and the detection 4 detect whether the laundry Q is biased. Can be executed with high accuracy. As a result, it is possible to improve the accuracy of detecting whether or not the laundry Q is biased.

  When the control unit 30 determines that the first count value E is caught by the detection 3 (YES in step S51) or determines that the correction duty ratio dn_diff is caught by the detection 4 (YES in step S52), the motor 6 is stopped (step S11 described above), and the corresponding processing of steps S12 to S18 described above is executed. The processes of steps S40 to S52 are included in step S20 (see FIG. 5A) described above.

  Step S16A and step S16B in FIG. 9B are included in step S16 (see FIG. 5B) described above. Specifically, the determination in step S16A corresponds to a determination as to whether or not the re-start-up is performed in step S16 in FIG. 5B, and the determination in step S16B corresponds to a determination as to whether or not the re-start-up is possible in step S16 in FIG. 5B. .

  When the dehydration condition is neither blanket course nor dehydration only (NO in step S12), the control unit 30 determines in step S16A whether the dehydration operation stopped this time is before restarting. If it is before re-startup (YES in step S16A), the control unit 30 determines whether the bias of the laundry Q is small enough that the first count value E and the correction duty ratio dn_diff are less than the upper threshold for each. to decide.

  If the first count value E and the correction duty ratio dn_diff are less than the upper threshold values for each before the restart (YES in step S16A) (YES in step S16B), the control unit 30 (Step S17).

  If it is not before restarting, that is, if it has been restarted (NO in step S16A), the control unit 30 executes unbalance correction (step S18). Even before re-startup (YES in step S16A), if at least one of the first count value E and the correction duty ratio dn_diff is greater than or equal to the upper threshold for each (NO in step S16B) The control unit 30 executes unbalance correction (step S18).

  Thus, when the control part 30 stops rotation of the spin-drying | dehydration tank 4 at step S11, in step S16B-S18, the bias | hook caught in the detection 3 or the detection 4 is small to the extent which can be restarted continuously. Whether the unbalance correction is necessary is determined according to the first count value E and the correction duty ratio dn_diff.

  That is, the control unit 30 performs the re-startup and unbalance correction depending on the degree of the first count value E and the correction duty ratio dn_diff, in other words, whether these values are equal to or higher than the upper threshold values. Select either one to execute. Therefore, if it is determined that there is a bias in the laundry Q, unbalance correction is not performed uniformly. Therefore, if the first count value E and the correction duty ratio dn_diff indicate that the bias of the laundry Q is small, the time for the dehydration operation can be shortened by executing the re-startup immediately.

  When it is determined that there is no bias in the laundry Q in both detection 3 and detection 4, if the value of the timer 35 has passed 8.1 seconds (NO in step S49), the control unit 30 detects 3 and detection 4 are terminated (step S53).

  Next, the detection 5 will be described in detail. Specifically, the detection 5 is divided into detection 5-1 and detection 5-2. FIG. 12 is a flowchart showing an outline of detection 5-1 and detection 5-2. The detection 5-1 and the detection 5-2 are detection of the presence or absence of the bias of the laundry Q using the duty ratio.

  Referring to FIG. 12, even after the end of detection 3 and detection 4, steady rotation of motor 6 at 240 rpm is continued for a predetermined time. As the predetermined time elapses, the control unit 30 accelerates the motor 6 from 240 rpm to the target rotational speed of 800 rpm described above (step S60).

  When the rotational speed of the motor 6 reaches 300 rpm in a state where the motor 6 is accelerated, the control unit 30 acquires the duty ratio of the voltage applied to the motor 6 at that time as an α value (step S61). 300 rpm is a rotational speed at which water is not accumulated in the dewatering tank 4 and is most unaffected by the eccentricity of the dewatering tank 4. Therefore, the α value at 300 rpm is a duty ratio in a state in which it is only affected by the load amount of the laundry Q without being affected most by the eccentricity of the dewatering tub 4.

  And the control part 30 implements the detection 5-1 mentioned above in the period whose rotation speed is 600 pm to 729 rpm in the state in which the motor 6 continued to be accelerated (step S62). If the detection 6-1 is not OK (NO in step S62), that is, if the control unit 30 determines that the laundry Q is biased, the control unit 30 stops the motor 6. The rotation of the dewatering tank 4 is stopped (step S63). After the dehydration operation is stopped in this way, the control unit 30 determines whether or not the re-start-up has been performed, that is, whether or not the re-start-up has been executed for the dehydration operation stopped this time (step S64).

  If it is before restarting (YES in step S64), control unit 30 executes restarting (step S65). If it is not before restarting (NO in step S64), control unit 30 executes imbalance correction (step S66).

  On the other hand, when the detection 5-1 is OK (YES in step S62), that is, when the control unit 30 determines in the detection 5-1 that the laundry Q is not biased, the control unit 30 In the state where the motor 6 is continuously accelerated from 730 rpm, the above-described detection 5-2 is continuously performed (step S67).

  If the detection 5-2 is OK (YES in step S67), that is, if the control unit 30 determines in the detection 5-2 that the laundry Q is not biased, the control unit 30 After accelerating the motor 6 to the target rotational speed (800 rpm), the dehydration of the laundry Q by continuously rotating the motor 6 at the target rotational speed is continued (step S68).

  On the other hand, when the detection 5-2 is not OK (NO in step S67), that is, when the control unit 30 determines that the laundry Q is biased, the control unit 30 performs the target rotation described above. The dehydration of the laundry Q by continuously rotating the motor 6 at a rotation speed of a few or less is continued (step S69).

Next, each of the detection 5-1 and the detection 5-2 will be described in detail.
FIG. 13 is a flowchart showing a control operation for detection 5-1.

  Referring to FIG. 13, the control unit 30 detects when the rotational speed of the motor 6 has reached 600 rpm in a state where the motor 6 continues to be accelerated after the above-described step S61 (see FIG. 12). 5-1 is started (step S70).

  Then, the control unit 30 starts counting by the counter 36 (step S71), and initializes the counter 36 every time 0.3 seconds elapse, thereby counting every 0.3 seconds (step S72 and step S71). S73).

  The control unit 30 obtains the number of rotations of the motor 6 at the time of counting and the duty ratio dn (n: count value) of the voltage applied to the motor 6 at the time of counting every time it counts (step S74). That is, the control unit 30 acquires the rotation speed of the motor 6 and the duty ratio dn at predetermined timings within a period until the rotation speed of the motor 6 reaches from 240 rpm to 800 rpm.

In step S74, the control unit 30 calculates a correction value Bn obtained by correcting the duty ratio dn with the above-described α value based on the following equation (3). Note that X and Y in Equation (3) are constants obtained by experiments and the like. Unlike simple proportional calculation, the detection 5-1 can be performed with high accuracy by the correction value Bn obtained by correcting the duty ratio dn by changing the weighting according to the equation (3).
Bn = dn− (α · X + Y) (3)

  In step S74, the control unit 30 calculates a movement integrated value Cn (n: count value) of the correction value Bn. The movement integrated value Cn (n: count value) is a value obtained by summing up five correction values Bn that are consecutive in the counting order. Incidentally, with a certain movement integrated value Cn and the movement integrated value Cn−1 immediately before it, the four rear correction values Bn and the movement integrated value Cn of the five correction values Bn constituting the movement integrated value Cn−1 are obtained. The four correction values Bn on the front side of the five correction values Bn are the same values. Note that the number of correction values Bn to be summed to constitute the movement integrated value Cn is not limited to the five described above.

Next, the control unit 30 calculates a threshold for the movement integrated value Cn based on the following equation (4) (step S75).
Threshold = (number of rotations) · a + b (4)

  In Expression (4), a and b are constants obtained by experiments or the like, and are stored in the memory 32. These constants a and b vary depending on the current rotational speed of the motor 6 and the selected dehydrating conditions. Therefore, there are a plurality of values for the threshold value at the same rotation speed. Note that it is clear from Equation (4) that the threshold value is not affected by the α value described above.

  Then, the control unit 30 checks whether or not the current rotational speed of the motor 6 is less than 730 rpm (step S76).

  When the current rotational speed of the motor 6 is less than 730 rpm (YES in step S76), the control unit 30 determines whether or not the latest movement integrated value Cn is caught by the detection 5-1 (step S77).

  FIG. 14 is a graph showing the relationship between the rotational speed and the movement integrated value Cn in relation to the detection 5-1 and the detection 5-2. In the graph of FIG. 14, the horizontal axis indicates the rotation speed (unit: rpm), and the vertical axis indicates the movement integrated value Cn. Referring to FIG. 14, the threshold values calculated in step S75 are, for example, two types of threshold values, a first threshold value indicated by a one-dot chain line and a second threshold value indicated by a two-dot chain line, depending on the difference in dehydration conditions. Is set. The first threshold is higher than the second threshold.

  The dehydration conditions include dehydration conditions in which water is stored in the dehydration tub 4 and the laundry Q is rinsed and then “rinse”, and the dehydration operation is performed by showering the laundry Q while draining. And other dehydration conditions such as “re-startup” described above. These dehydrating conditions are selected by the operation of the operation unit 20 by the user, and the selection is accepted by the control unit 30. In the dehydration operation after washing operation or rinsing, a large amount of water is contained in the laundry. Therefore, it is necessary to accelerate the motor 6. However, in the case of shower dehydration or re-startup, some water is discharged from the laundry. Since it is in the detached state, the force required for accelerating the motor 6 can be small.

  The control unit 30 uses a first threshold value higher than the second threshold value because it is a severe detection if the second threshold value is used in the dehydration operation after the washing operation or the rinsing operation. On the other hand, in the dewatering operation such as shower dewatering or re-start-up, the control unit 30 uses a second threshold value lower than the first threshold value because the first threshold value is a loose detection. Therefore, even when the laundry Q contains a large amount of water or when some amount of water has drained from the laundry Q, the detection 5-1 is executed using a threshold suitable for each case.

  Further, for the same purpose as the difference in the dehydration conditions, when the load amount of the laundry Q in the dehydration tub 4 is large, the control unit 30 detects that the second threshold value is severe in the detection 5-1. Therefore, the first threshold value higher than the second threshold value is used. In addition, when the load amount of the laundry Q in the dehydrating tub 4 is small, the control unit 30 makes a loose detection when it is the first threshold value in the detection 5-1, so that the second threshold value lower than the first threshold value Is used. Therefore, detection 5-1 is performed using a threshold suitable for each case where the load amount of the laundry Q is different.

  In FIG. 14, two types of threshold values, the first threshold value and the second threshold value, are illustrated, but three or more types of threshold values may be set according to various dehydration conditions and load amounts.

  Then, when the eccentricity is large and the laundry Q is biased (see the broken line in FIG. 14), compared to the case where the eccentricity is small and the laundry Q is not biased (see the solid line), the integrated movement value at each rotation speed. Cn increases. If the bias of the laundry Q is large, the movement integrated value Cn exceeds the corresponding threshold value in the set threshold value, that is, the first threshold value and the second threshold value.

  Therefore, returning to FIG. 13, if the latest movement integrated value Cn is equal to or greater than the set threshold, the control unit 30 determines that the movement integrated value Cn is caught by the detection 5-1 (YES in step S77).

  If the control unit 30 determines that the movement integrated value Cn is caught by the detection 5-1 (YES in step S77), the control unit 30 stops the rotation of the motor 6 (step S63 described above), and corresponds to the steps S64 to S66 described above. Execute the process. The processing of steps S71 to S77 is included in step S62 (see FIG. 12) described above.

  Then, when the rotation number of the motor 6 reaches 730 rpm (NO in step S76) in the state where it is determined that there is no bias in the laundry Q in the detection 5-1, the control unit 30 ends the detection 5-1. Subsequently, the detection 5-2 is started (step S78).

FIG. 15 is a flowchart showing a control operation for detection 5-2.
Referring to FIG. 15, control unit 30 starts detection 5-2 in response to the number of rotations of motor 6 reaching 730 rpm in a state where motor 6 is continuously accelerated (step S78 described above). .

  Then, the control unit 30 starts counting by the counter 36 (step S79), and counts every 0.3 seconds by initializing the counter 36 every time 0.3 seconds elapse (step S80 and step S80). S81).

  Similarly to step S74 in detection 5-1, the control unit 30 obtains the number of rotations of the motor 6 at the time of counting and the duty ratio dn of the voltage applied to the motor 6 at the time of counting each time counting is performed. Then, the correction value Bn and the movement integration value Cn are calculated (step S82).

  Next, the control unit 30 calculates a threshold for the movement integrated value Cn based on the above-described equation (4) (step S83). The constants a and b constituting the equation (4) differ depending on the current rotational speed of the motor 6 and the selected dehydrating conditions, as in the case of the detection 5-1. Therefore, the threshold value here has a plurality of values such as the first threshold value and the second threshold value described above at the same rotation speed.

  Then, the control unit 30 checks whether or not the current rotational speed of the motor 6 has reached the target rotational speed (800 rpm) (step S84).

  When the current rotational speed of the motor 6 is less than the target rotational speed (YES in step S84), the control unit 30 detects the latest movement integrated value Cn as in the case of detection 5-1 (step S77). It is determined whether or not it has been caught at 5-2 (step S85).

  Specifically, referring to FIG. 14, when the eccentricity is large and the laundry Q is biased (see the broken line in FIG. 14), the eccentricity is small and the laundry Q is not biased (see the solid line). The movement integrated value Cn at each rotational speed increases. If the bias of the laundry Q is large, the movement integrated value Cn exceeds the corresponding threshold value in the set threshold value, that is, the first threshold value and the second threshold value.

  Therefore, returning to FIG. 15, if the latest movement integrated value Cn is equal to or greater than the set threshold value, the control unit 30 determines that the movement integrated value Cn is caught by the detection 5-2 (YES in step S85).

  When determining that the movement integrated value Cn is caught by the detection 5-2 (YES in step S85), the control unit 30 acquires the determination point, that is, the rotation speed L of the motor 6 at the time of detection 5-2 ( Step S86).

  Then, the control unit 30 performs the steady rotation of the motor 6 by rotating the motor 6 at a rotational speed obtained by rounding down the obtained rotational speed L, strictly speaking, the first digit of the rotational speed L to 0 (zero). The dehydration of the product Q is continued (step S69 described above). At this time, the control unit 30 extends the dehydration time at the rotation speed L so that the same dehydration effect as when dewatering at the original target rotation speed is obtained.

  Then, when it is determined in the detection 5-2 that the laundry Q is not biased and the rotational speed of the motor 6 reaches the target rotational speed (NO in step S84), the control unit 30 performs the detection 5-2. After completion, the dehydration of the laundry Q is continued by rotating the motor 6 at the target rotational speed (step S68 described above).

  As described above, in the detection 5-1 and the detection 5-2, the control unit 30 changes the threshold according to the dehydration condition received by the operation unit 20 (step S75 and step S83). Then, the control unit 30 performs washing in the dewatering tub 4 if the acquired duty ratio dn, strictly speaking, the integrated movement value Cn calculated based on the acquired duty ratio dn is equal to or greater than the changed predetermined threshold value. It is determined that the object Q is biased. That is, in the dehydration operation under each dehydration condition, whether or not the laundry Q is biased can be detected based on a threshold value suitable for each dehydration condition, so that the detection accuracy of the presence or absence of the laundry Q can be improved.

  The present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the claims.

  For example, during the dehydration operation, particularly during a period in which the rotation speed of the motor 6 is less than 600 rpm, a phenomenon may occur in which bubbles are clogged in the drainage channel 14 and not smoothly drained. Therefore, the control unit 30 may execute the control for detecting bubbles in the drainage channel 14 in parallel with the control related to the detections 1 to 5 described above.

FIG. 16 is a flowchart showing a control operation for detecting bubbles during the dehydration operation.
Referring to FIG. 16, the control unit 30 starts the dehydration rotation of the dehydration tank 4 by the start of the dehydration operation (step S1 described above). Thereby, the rotation speed of the motor 6 rises as described above (see FIG. 3).

  The control unit 30 acquires the number of rotations of the motor 6 and an applied voltage duty ratio that is a duty ratio of a voltage applied to the motor 6 at every predetermined timing during the dehydration operation (step S91).

  If the rotation speed of the motor 6 is less than 600 rpm (YES in step S92), the control unit 30 calculates a voltage limit value V_limit (step S93). The voltage limit value V_limit is a duty ratio of the maximum voltage applied to the motor 6 for each rotation speed, and is calculated by substituting the rotation speed into a predetermined formula.

  And the control part 30 detects the bubble in the drainage channel 14 by confirming whether the applied voltage duty ratio acquired by step S91 is more than voltage limit value V_limit in each timing (step S94).

  Specifically, when the drainage channel 14 is clogged with bubbles and water cannot be drained, water accumulates at the bottom of the dewatering tank 4 and becomes a resistance to rotation of the dewatering tank 4, so that the dewatering tank 4 is rotated by the voltage limit value V_limit A voltage corresponding to the above applied voltage duty ratio must be applied to the motor 6. Therefore, if the applied voltage duty ratio is equal to or greater than the voltage limit value V_limit, the control unit 30 determines that the drainage channel 14 is clogged with bubbles (YES in step S94). On the other hand, if the applied voltage duty ratio is less than the voltage limit value V_limit, the control unit 30 determines that the drainage channel 14 is not clogged with bubbles (NO in step S94).

  When determining that the drainage channel 14 is clogged with bubbles (YES in step S94), the control unit 30 determines whether or not the re-start-up has been executed with respect to the de-run operation that has been stopped this time. Judgment is made (step S95).

  If it is before the restart (YES in Step S95), the control unit 30 executes the restart (Step S96). If it is not before restarting (NO in step S95), the control unit 30 executes unbalance correction (step S97). Regardless of whether the re-startup or the unbalance correction is performed, the dehydration operation is temporarily stopped and then restarted. Therefore, the bubbles in the drainage channel 14 naturally disappear while the dehydration operation is performed again.

  On the other hand, if the rotation speed of the motor 6 is 600 rpm or more (NO in step S92), the control unit 30 ends the process of detecting bubbles (step S98).

  Further, the control of FIG. 16 can be used not only to detect bubbles but also to detect a phenomenon of “water catch” in which water in the outer tub 3 cannot reach the drainage channel 14 due to vibration or the like.

  In addition, in the above-described low-speed eccentricity detection section (see FIG. 3) in the dehydration operation, detection 1 to detection 4 are executed in order to electrically detect whether or not the laundry Q is biased in the dehydration tank 4. The detection 6 described below may be executed instead of the detection 1 to the detection 4, or may be executed in parallel with the detection 1 to the detection 4.

  FIG. 17 is a time chart showing the state of the number of rotations of the motor 6 during the dehydration operation in relation to the detection 6, and more specifically, a diagram corresponding to the low-speed eccentricity detection section in FIG. is there. Therefore, in the time chart of FIG. 17, the horizontal axis indicates the elapsed time, and the vertical axis indicates the rotation speed (unit: rpm) of the motor 6 as in FIG. In FIG. 17, in addition to the state of the rotational speed of the motor 6 indicated by a solid line, the state of the duty ratio of the voltage applied to the motor 6 by the control unit 30 is indicated by a broken line for reference. .

  Referring to FIG. 17, in the low-speed eccentricity detection section, control unit 30 controls the duty ratio so that the maximum value of the duty ratio is generated in the middle of the acceleration state of motor 6 from 120 rpm to 240 rpm. At this time, the acceleration of the motor 6 is controlled so as to be always constant. Hereinafter, the maximum value of the duty ratio that occurs during the acceleration state of the motor 6 will be referred to as the maximum duty ratio dmax. Specifically, the control unit 30 sets the maximum duty ratio dmax when the rotation speed (for example, 180 rpm) is slightly lower than the rotation speed (for example, 200 rpm to 220 rpm) at which resonance of the dehydration tank 4 occurs, specifically, longitudinal resonance occurs. The duty ratio is controlled so as to be generated.

  Such control of the duty ratio is executed in common regardless of the load amount of the laundry Q in the dewatering tub 4. In addition, in order to realize this control, the control unit 30 preliminarily calculates a difference between the target rotational speed of the motor 6 and the current actual rotational speed, a gain indicating the responsiveness of the rotational speed to a change in the duty ratio, and the like. Is set. In the following, the rotational speed at which longitudinal resonance occurs may be referred to as longitudinal resonant rotational speed.

  When the control unit 30 starts accelerating the motor 6 from 120 rpm, the duty ratio gradually increases as shown by a broken line in FIG. The maximum duty ratio dmax is generated when the rotation speed of the motor 6 reaches 180 rpm. If the laundry Q is not biased in the dewatering tub 4, after the maximum duty ratio dmax is generated, the motor 6 can be accelerated up to 240 rpm even if the duty ratio is small, so that the duty ratio gradually decreases as shown by a broken line.

  However, if the laundry Q is biased in the dewatering tub 4, vibration increases as the rotational speed of the motor 6 approaches the longitudinal resonance rotational speed. For this reason, in order for the motor 6 to accelerate to 240 rpm, the duty ratio must be increased even after the maximum duty ratio dmax is generated. Therefore, the duty ratio after the maximum duty ratio dmax is difficult to decrease. Therefore, even after the maximum duty ratio dmax occurs, the duty ratio does not decrease while maintaining a value slightly lower than the maximum duty ratio dmax as shown by a one-dot chain line in FIG. As shown, it may increase after it becomes lower than the maximum duty ratio dmax. In the detection 6, the relative change of the duty ratio with respect to the maximum duty ratio dmax after the generation of the maximum duty ratio dmax is monitored in this manner, thereby electrically detecting whether or not the laundry Q is biased in the dewatering tub 4. To do.

  FIG. 18 is a flowchart showing the control operation for the detection 6. The detection 6 will be described with reference to FIG.

  In step S4 described above, the control unit 30 starts accelerating the motor 6 from 120 rpm to 240 rpm. Then, in the acceleration state of the motor 6 up to 240 rpm, when the rotation speed of the motor 6 reaches, for example, 180 rpm, the duty ratio becomes the maximum value, so the control unit 30 acquires this maximum value as the maximum duty ratio dmax ( Step S101).

  In relation to the detection 6, the count value G and the integrated value H exist and are stored in the memory 32. The control unit 30 clears each of the count value G and the integrated value H to an initial value of 0 (zero) when acquiring the maximum duty ratio dmax (step S101).

  Then, after obtaining the maximum duty ratio dmax, when the rotational speed of the motor 6 reaches the rotational speed immediately before the occurrence of longitudinal resonance (for example, 200 rpm) (YES in step S102), the control unit 30 starts the timer 35. Thus, time measurement is started and counting by the counter 36 is started (step S103). Thereby, the detection 6 is started. The control unit 30 refers to the value of the timer 35 and initializes the counter 36 every time a predetermined time (for example, 0.1 second) elapses, thereby counting every 0.1 second (Step S104 and Step S40). S105). The control unit 30 increments (+1) the count value G at the timing of initializing the counter 36 in step S105, that is, at every count.

  The control unit 30 acquires the duty ratio dg (g: count value G) of the voltage applied to the motor 6 at the time of counting every time it counts (step S106). That is, the control unit 30 acquires the duty ratio dg every predetermined time of 0.1 seconds.

  In step S106, the control unit 30 obtains the duty ratio dg every predetermined time, and at the same time, calculates the integrated value H of the difference between the duty ratio dg and the maximum duty ratio dmax. This difference is a value obtained by subtracting the duty ratio dg from the maximum duty ratio dmax. The integrated value H is a value obtained by adding the latest difference to the previous integrated value H, and the count value G is incremented. Updated every time.

  FIG. 19 is a graph showing the relationship between the count value G and the integrated value H in relation to the detection 6. In the graph of FIG. 19, the horizontal axis indicates the count value G, and the vertical axis indicates the integrated value H. Referring to FIG. 19, if the eccentricity is small and the laundry Q is not biased in the dewatering tub 4, as described above, the duty ratio gradually decreases after the maximum duty ratio dmax is generated. As a result, the difference between the duty ratio dg and the maximum duty ratio dmax gradually increases, so that the integrated value H increases as shown by a solid line. On the other hand, if the eccentricity is large and the laundry Q is biased in the dewatering tub 4, the duty ratio after the maximum duty ratio dmax is difficult to decrease as described above. As a result, the difference between the duty ratio dg and the maximum duty ratio dmax is unlikely to increase, so the integrated value H is unlikely to increase as indicated by the broken line.

A predetermined threshold value is set for the integrated value H. This threshold value is obtained from the following equation (5) using the count value G incremented every predetermined time and the maximum duty ratio dmax as variables.
Threshold = (K · G−L) −M · (N−dmax) (5)
K, L, M, and N in Expression (5) are constants obtained in advance by experiments or the like, and are stored in the memory 32. As indicated by a one-dot chain line in FIG. 19, the threshold value varies so as to increase as the count value G increases. The threshold value may be stored in the memory 32 in advance, or may be calculated by the control unit 30 based on Expression (5) every time the count value G varies.

  Referring to FIG. 18, when the timing at which count value G reaches 20, for example, the timing at which longitudinal resonance starts (YES in step S107), control unit 30 determines that the latest integrated value H is an expression ( It is confirmed whether it is less than the predetermined threshold obtained in 5) (step S108). If the integrated value H is less than the threshold value (YES in step S108), the control unit 30 determines that the laundry Q is biased in the dewatering tub 4 and stops the motor 6 (step S109). Thereby, rotation of the dehydration tank 4 is stopped. After the motor 6 is stopped, the processes of steps S11 to S18 (see FIG. 5B) may be executed in the same manner as the detections 1 to 4.

  If integrated value H does not fall below a predetermined threshold (NO in step S108) and count value G reaches a predetermined value (for example, 81) (YES in step S110), the rotational speed of motor 6 reaches 240 rpm, and the motor 6 is in a state of steady rotation at 240 rpm. In this case, the control unit 30 ends the detection 6 (step S111).

  As described above, in the detection 6 that monitors the integrated value H that is an index indicating the relative change of the duty ratio dg with respect to the maximum duty ratio dmax after the generation of the maximum duty ratio dmax, the detection accuracy of whether the laundry Q is biased is detected. Improvements can be made.

  In particular, in detection 6, the duty ratio is set so that the maximum duty ratio dmax is generated at a rotational speed slightly lower than the longitudinal resonance rotational speed. In this case, longitudinal resonance occurs at an early timing after the maximum duty ratio dmax is generated. As a result, the phenomenon that the integrated value H is difficult to increase occurs quickly. Therefore, it can be detected early and accurately that there is a bias of the laundry Q in the dewatering tub 4. Further, if the maximum duty ratio dmax is generated at the longitudinal resonance rotational speed, there may be a problem that the subsequent rotational speed fluctuation becomes unstable. However, in this embodiment, such a problem can be suppressed by generating the maximum duty ratio dmax when the rotational speed is slightly lower than the longitudinal resonance rotational speed.

  FIG. 20 is a graph showing the relationship between the count value G and the duty ratio in relation to the detection 6. In the graph of FIG. 20, the horizontal axis indicates the count value G, and the vertical axis indicates the duty ratio. Referring to FIG. 20, when the load amount is large, as shown by the solid line, a large duty ratio is required to accelerate the rotational speed of motor 6 at a constant acceleration, and the maximum duty ratio dmax is increased accordingly. . On the other hand, when the load amount is small, as indicated by the broken line, the duty ratio for accelerating the rotation speed of the motor 6 at a constant acceleration may be small, and the maximum duty ratio dmax is accordingly reduced. Therefore, regarding the difference between the duty ratio dg and the maximum duty ratio dmax when a predetermined time has elapsed since the maximum duty ratio dmax has occurred, the difference R when the load amount is small is the difference S when the load amount is large. It is significantly smaller than that. Therefore, the integrated value H when the load amount is small is less likely to increase than when the load amount is large, and it is assumed that the integrated value H is below the threshold value even though the laundry Q is not biased. In this case, when the load amount is small, it is erroneously detected that the laundry Q is biased and the dehydration operation may be stopped.

  Therefore, the threshold value is obtained from Expression (5) using the count value G and the maximum duty ratio dmax as variables as described above. Therefore, the maximum duty ratio dmax varies depending on the load amount of the laundry Q in the dewatering tub 4, and therefore the threshold value is determined to be different for each load amount. Thereby, in the detection 6, since the presence or absence of the bias of the laundry Q is detected based on the optimal threshold value according to the magnitude of the load amount of the laundry Q in the dewatering tub 4, the load amount is small. Even if it exists, false detection can be prevented. Therefore, it is possible to further improve the accuracy of detecting whether or not the laundry Q is biased.

  In the above embodiment, the motor 6 is controlled using the duty ratio on the assumption that the motor 6 is an inverter motor. However, when the motor 6 is a brush motor, the motor 6 is replaced with the duty ratio. The motor 6 is controlled using the value of the applied voltage.

  In the above description, specific numerical values such as 120 rpm, 240 rpm, and 800 rpm are used for the rotational speed, but these specific numerical values are values that vary depending on the performance of the dehydrator 1. In the above description, the duty ratio is acquired and used for various determinations. However, the duty ratio may be raw data of the acquired duty ratio, and is corrected as necessary. It may be a correction value, or may be a value calculated from the duty ratio, such as the movement integrated value Cn described above.

  Further, the dehydrating tank 4 of the above embodiment is vertically arranged so as to be rotatable around the axis 16 extending in the vertical direction X. However, the dehydration tank 4 is removed by extending the axis 16 inclined with respect to the vertical direction X. The water tank 4 may be disposed obliquely.

DESCRIPTION OF SYMBOLS 1 Dehydrator 4 Dehydration tank 6 Motor 30 Control part dg Duty ratio dmax Maximum duty ratio dn Duty ratio d0 Reference duty ratio dn_diff Correction duty ratio
E First count value G Count value H Integrated value Q Laundry

Claims (5)

A dewatering tub that houses laundry and rotates to dehydrate the laundry;
An electric motor for rotating the dehydration tank;
A load amount measuring means for measuring the load amount of the laundry in the dewatering tank at the start of rotation of the dewatering tank;
After the load amount is measured by the load amount measuring means, the duty ratio of the voltage applied to the motor is controlled to cause the motor to rotate at a first rotation speed, and then the laundry is fully dehydrated. Drive control means for causing the motor to rotate at a second rotational speed higher than the first rotational speed,
Acquisition means for acquiring, as a reference duty ratio, a duty ratio of a voltage applied to the motor in an acceleration state of the motor up to the first rotation speed;
Timing determining means for determining the timing at which the acquisition means acquires the reference duty ratio;
After the acquisition means acquires the reference duty ratio, a state in which the duty ratio of the voltage applied to the motor changes from the reference duty ratio in order to maintain the first rotation speed within a predetermined period. Determination means for determining the presence or absence of bias of the laundry in the dewatering tank based on the index,
If the determination means determines that there is a bias in the laundry, including a stop control means for stopping the rotation of the dewatering tank,
The timing determining means determines the timing at which the acquisition means acquires the reference duty ratio according to the load amount measured by the load amount measuring means.   When the stop control means stops the rotation of the dehydrating tub, either the rotation of the dehydrating tub for restarting the dehydration of the laundry or the process of correcting the bias of the laundry in the dehydrating tub The dehydrator according to claim 1, further comprising execution means for selecting and executing the operation according to the index. The drive control means rotates the motor at a predetermined speed lower than the first rotation speed before rotating the motor at the first rotation speed.
The said execution means shortens the period which makes the said motor rotate regularly at the said predetermined speed, when performing rotation of the said dehydration tank for restarting dehydration of the laundry. Dehydrator. A dewatering tub that houses laundry and rotates to dehydrate the laundry;
An electric motor for rotating the dehydration tank;
By controlling the duty ratio of the voltage applied to the motor, the motor is steadily rotated at a first rotational speed, and then the first rotational speed higher than the first rotational speed is used to fully dehydrate laundry. Drive control means for rotating the motor at a rotational speed of 2,
An acquisition means for acquiring the duty ratio at predetermined timings within a predetermined period after starting acceleration of the motor toward the first rotation speed;
If the duty ratio acquired by the acquisition unit is equal to or greater than the duty ratio acquired immediately before, the count value with an initial value of zero is incremented, and the duty ratio acquired by the acquisition unit is acquired immediately before Counting means for resetting the count value to the initial value if less than a duty ratio;
If the count value is equal to or greater than a predetermined threshold value, a determination unit that determines that there is a bias in the laundry in the dewatering tank;
A dehydrator comprising stop control means for stopping rotation of the dewatering tub when the determination means determines that there is a bias in the laundry. A dewatering tub that houses laundry and rotates to dehydrate the laundry;
An electric motor for rotating the dehydration tank;
By controlling the duty ratio of the voltage applied to the motor, the motor is steadily rotated at a first rotational speed, and then the first rotational speed higher than the first rotational speed is used to fully dehydrate laundry. Drive control means for rotating the motor at a rotational speed of 2,
An acquisition means for acquiring the duty ratio at every predetermined timing within a period until the rotation speed of the motor reaches the second rotation speed from the first rotation speed;
If the duty ratio acquired by the acquisition means is equal to or greater than a predetermined threshold, determination means for determining that there is a bias in the laundry in the dewatering tub,
If the determination means determines that there is a bias in the laundry, a stop control means for stopping the rotation of the dewatering tub,
An accepting means for accepting a selection of laundry dehydration conditions;
A dehydrator comprising: a threshold value changing unit that changes the threshold value according to a dehydrating condition for which the receiving unit has received selection.

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