JP7142287B2 - washing machine - Google Patents

Description

The present invention relates, for example, to a washing machine that performs washing, rinsing and spin-drying processes.

As a conventional washing machine, Patent Document 1 describes a washing machine in which a drum for containing laundry is arranged inside an outer tub. In this washing machine, water passage holes are formed in the peripheral wall of the drum, the water dehydrated from the laundry in the drum is discharged to the outer tub through the water passage holes, and the water in the outer tub is discharged through the drain port. be done. A motor for rotating the drum is installed below the outer tub.

In the dehydration process of a washing machine, if there is an imbalance in the drum due to the way the laundry sticks to the inner wall of the drum, etc., the eccentricity of the drum during rotation increases and the rotation becomes large if the unevenness of the laundry is large. Since torque is required, there is a problem that the dehydration operation cannot be started.

Therefore, Patent Document 1 discloses a motor control circuit focusing on the fact that fluctuations in motor current are caused by fluctuations in load torque, and that the peak of motor current occurs at the timing when the load torque reaches its maximum within one rotation period of the drum. A washing machine is described in which torque fluctuation is detected through a torque current of an inverter constituting a washing machine, and an unbalanced amount of laundry is detected from the torque fluctuation. In this washing machine, when the imbalance amount is greater than a predetermined value, the balance adjustment operation is performed to eliminate the unevenness of the laundry.

JP-A-9-290089

In the dehydration process of a washing machine, the water contained in the laundry is discharged to the outside through the drainage path of the washing machine. If the path configuration is bad, water may remain between the drum and the outer tub, and the water may act as a resistance and hinder the rotation of the drum. Further, when the drum is rotated with water remaining between the drum and the outer tub, an abnormal sound may be generated, and the abnormal sound increases as the rotation speed of the drum increases.

Therefore, in a washing machine, if water remains between the drum and the outer tub without being drained, it is necessary to take appropriate measures.

However, when the drum is rotated while water remains between the drum and the outer tub, the remaining water between the drum and the outer tub acts as a resistance, increasing the load on the motor for rotating the drum. growing. Therefore, in a washing machine that detects the unevenness of the laundry based on the current value of the motor, as in Patent Document 1, it is erroneously detected that the amount of unbalance is large, and the balance adjustment operation is repeated many times.

Further, conventional washing machines include an acceleration sensor that detects the acceleration of the drum, and detect the amount of unbalance, which is the bias of the laundry, based on the acceleration detected by the acceleration sensor.

However, the acceleration sensor detects the vibration (acceleration) of the drum. small. Therefore, it is not possible to detect the state in which water remains between the drum and the outer tub based on the acceleration of the drum detected by the acceleration sensor.

Therefore, the inventors of the present invention have studied a method for detecting a state in which water remains between the drum and the outer tank. It was found that by using both, it is possible to detect the state in which water remains between the drum and the outer tank.

SUMMARY OF THE INVENTION An object of the present invention is to provide a washing machine capable of taking appropriate measures by detecting that water remains between a drum and an outer tub.

That is, the washing machine of the present invention comprises a cylindrical drum with a bottom that is rotatable about an axis, a motor that rotates the drum via a drive shaft protruding from the bottom of the drum, and a motor that drives the drum. an acceleration sensor for detecting acceleration, and a first output difference obtained by subtracting the output of the motor from the output of the acceleration sensor after the number of revolutions of the drum reaches or exceeds a predetermined number of revolutions in the dehydration process is smaller than a first threshold. or when a second output difference obtained by subtracting the output of the acceleration sensor from the output of the motor is equal to or greater than a first threshold value, a determination means for determining that the rotational speed of the drum cannot be increased; and a control means for controlling the motor based on the determination, the output of the motor is the difference between the current value of the motor at the present time and the current value of the motor when the number of revolutions of the drum is the predetermined number of revolutions. The difference is digitalized by AD conversion, and the output of the acceleration sensor is digitalized by AD conversion of the acceleration change amount within one rotation period of the drum .

In the washing machine of the present invention, the determining means determines that the first output difference becomes equal to or greater than a second threshold value after determining that the number of rotations of the drum cannot be increased, or the second output difference increases to the second threshold value. It is characterized in that it is determined that the number of revolutions of the drum can be increased when the number of revolutions is smaller than two thresholds.

The washing machine according to the present invention is characterized in that the second threshold for the first output difference is greater than the first threshold, or the second threshold for the second output difference is less than the first threshold.

In the washing machine of the present invention, a bottomed cylindrical drum configured to be rotatable around an axis, a motor for rotationally driving the drum via a drive shaft protruding from the bottom of the drum, and an acceleration of the drum. When a first output ratio obtained by dividing the output of the acceleration sensor by the output of the motor after the rotation speed of the drum reaches a predetermined rotation speed or more in the dehydration process is smaller than a first threshold, Alternatively, when a second output ratio obtained by dividing the output of the motor by the output of the acceleration sensor is equal to or greater than a first threshold value, a determination means for determining that the number of revolutions of the drum cannot be increased, and determination by the determination means. and the output of the motor is the difference between the current value of the motor at the present time and the current value of the motor when the number of revolutions of the drum is the predetermined number of revolutions. , and the output of the acceleration sensor is obtained by AD-converting and digitizing the amount of acceleration change within one rotation period of the drum .

In the washing machine of the present invention, the determining means determines that the first output ratio becomes equal to or greater than a second threshold value after determining that the number of rotations of the drum cannot be increased, or the second output ratio increases to the second It is characterized in that it is determined that the number of revolutions of the drum can be increased when the number of revolutions is smaller than two thresholds.

The washing machine according to the present invention is characterized in that the second threshold for the first output ratio is greater than the first threshold, or the second threshold for the second output ratio is less than the first threshold.

The washing machine of the present invention comprises a cylindrical drum with a bottom that is rotatable about an axis, a motor that rotates the drum through a drive shaft projecting from the bottom of the drum, and an acceleration of the drum. and an acceleration sensor for detecting when the output of the motor is equal to or higher than the motor threshold value and the output of the acceleration sensor is lower than the acceleration threshold value after the number of rotations of the drum reaches or exceeds a predetermined number of rotations in the dehydration process. and control means for controlling the motor based on the determination by the determination means, the output of the motor being the current value of the motor and the The difference between the current value of the motor when the number of rotations is the predetermined number of rotations is AD-converted and digitized, and the output of the acceleration sensor is the acceleration change amount within one rotation period of the drum. , is digitalized by AD conversion .

In the washing machine of the present invention, when the output of the motor becomes smaller than the motor threshold in a state where the output of the acceleration sensor is smaller than the acceleration threshold after the determination means determines that the rotation speed of the drum cannot be increased. Secondly, it is determined that the rotational speed of the drum can be increased.

In the washing machine according to the present invention, the determination means determines that the rotation speed of the drum cannot be increased or that the rotation of the drum is stopped when the output of the acceleration sensor is equal to or greater than the acceleration threshold.

In the washing machine of the present invention, the control means controls the motor so that the rotation speed of the drum is maintained for a predetermined time when the determination means determines that the rotation speed of the drum cannot be increased. characterized by

In the washing machine according to the present invention, the determination means determines that the rotation speed of the drum cannot be increased when the output of the acceleration sensor does not change when the rotation speed of the drum increases.

In the washing machine of the present invention, the first output difference obtained by subtracting the output of the motor from the output of the acceleration sensor is smaller than the first threshold value, or is equal to or greater than the second output difference obtained by subtracting the output of the acceleration sensor from the output of the motor. Based on this, it is detected that water remains between the drum and the outer tank, and the number of revolutions of the drum is prevented from increasing. Therefore, in the dehydration process, it is possible to prevent abnormal noise from being generated by increasing the rotation speed of the drum while water remains between the drum and the outer tub.

In the washing machine of the present invention, the first output difference obtained by subtracting the output of the motor from the output of the acceleration sensor is greater than or equal to the second threshold value, or the second output difference obtained by subtracting the output of the acceleration sensor from the output of the motor. Based on the decrease, it is detected that the state in which water remains between the drum and the outer tank is eliminated, and the rotation speed of the drum is increased. Therefore, in the dehydration process, when the state in which water remains between the drum and the outer tub is eliminated, the rotational speed of the drum can be increased to accelerate the dehydration.

In the washing machine of the present invention, the second threshold for detecting that the state in which water remains between the drum and the outer tub is eliminated is the state in which water remains between the drum and the outer tub. Since it is different from the first threshold for detecting , in the dehydration process, when the state where water remains between the drum and the outer tank is surely resolved, the rotation speed of the drum is increased to accelerate dehydration. can.

In the washing machine of the present invention, the first output ratio obtained by dividing the output of the acceleration sensor by the output of the motor is smaller than the first threshold, or the second output ratio obtained by dividing the output of the motor by the output of the acceleration sensor is the first Based on the fact that the threshold value is exceeded, it is detected that water remains between the drum and the outer tank, and the rotational speed of the drum is prevented from increasing. Therefore, in the dehydration process, it is possible to prevent abnormal noise from being generated by increasing the rotation speed of the drum while water remains between the drum and the outer tub.

In the washing machine of the present invention, the first output ratio obtained by dividing the output of the acceleration sensor by the output of the motor is equal to or greater than the second threshold, or the second output ratio obtained by dividing the output of the motor by the output of the acceleration sensor is reached. Based on the fact that the water has become smaller than the second threshold value, it is detected that the state in which water remains between the drum and the outer tank has been eliminated, and the rotational speed of the drum is increased. Therefore, in the dehydration process, when the state in which water remains between the drum and the outer tub is eliminated, the rotational speed of the drum can be increased to accelerate the dehydration.

In the washing machine of the present invention, the second threshold for detecting that the state in which water remains between the drum and the outer tub is eliminated is the state in which water remains between the drum and the outer tub. Since it is different from the first threshold for detecting , in the dehydration process, when the state where water remains between the drum and the outer tank is surely resolved, the rotation speed of the drum is increased to accelerate dehydration. can.

In the washing machine of the present invention, it is detected that water remains between the drum and the outer tub based on the fact that the output of the motor is equal to or higher than the motor threshold value and the output of the acceleration sensor is smaller than the acceleration threshold value, It prevents the rotation speed of the drum from increasing. Therefore, in the dewatering process, it is possible to prevent the occurrence of abnormal noise caused by rotating the drum with water remaining between the drum and the outer tub.

In the washing machine of the present invention, when the output of the acceleration sensor is smaller than the acceleration threshold and the output of the motor becomes smaller than the motor threshold, the state in which water remains between the drum and the outer tub is eliminated. This is detected and the rotation speed of the drum is increased. Therefore, in the dehydration process, when the state in which water remains between the drum and the outer tub is eliminated, the rotational speed of the drum can be increased to accelerate the dehydration.

In the washing machine of the present invention, based on the fact that the output of the acceleration sensor is equal to or higher than the acceleration threshold, it is detected that the laundry is unevenly distributed, and the rotation speed of the drum is prevented from increasing. Therefore, in the spin-drying process, it is possible to prevent the occurrence of vibration and noise caused by increasing the number of rotations of the drum when the laundry is largely uneven.

In the washing machine of the present invention, when the determining means determines that the rotation speed of the drum cannot be increased, the rotation speed of the drum is maintained for a predetermined time. operating efficiency is improved.

In the washing machine of the present invention, since the output of the acceleration sensor does not change when the rotation speed of the drum increases, it is highly likely that the acceleration sensor is out of order. Therefore, based on the output of the acceleration sensor at that time, it is possible to prevent the number of revolutions of the drum from increasing while water remains between the drum and the outer tub.

It is a typical sectional view of washing machine 1 concerning a 1st embodiment of the present invention. 2 is a control block diagram of the washing machine 1 of FIG. 1. FIG. It is a figure which shows the calculation method of a motor output. FIG. 4 is a diagram showing a method of calculating acceleration output; 4 is a graph showing waveforms of acceleration signals from the acceleration sensor 12. FIG. 2 is a flow chart showing the operation of the washing machine 1 of FIG. 1 when determining whether an acceleration sensor has failed. 3 is a flow chart showing the operation of the dewatering process of the washing machine 1 of FIG. 1; It is a control block diagram of the washing machine according to the second embodiment of the present invention. FIG. 9 is a flow chart showing the operation of the dewatering process of the washing machine of FIG. 8; FIG. It is a control block diagram of a washing machine according to a third embodiment of the present invention. 11 is a flow chart showing the operation of the dewatering process of the washing machine of FIG. 10;

(First embodiment)
A first embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a washing machine 1 according to a first embodiment of the invention. The washing machine 1 of this embodiment can be suitably used, for example, at a laundromat or at home. This is a so-called drum-type washing machine that includes a washing tub 1b, a driving device 20, and a control section 50. As shown in FIG.

A washing machine main body 1a shown in FIG. 1 has a substantially rectangular parallelepiped shape. An opening 11 for putting laundry in and out of the drum 2 is formed in the front surface 10a of the washing machine main body 1a, and an opening/closing lid (not shown) capable of opening and closing the opening 11 is attached. The washing machine 1 according to this embodiment is called a drum-type fully automatic washing machine in which the washing tub 1b is installed in a substantially horizontal direction.

The outer tub 3 is a cylindrical member with a bottom disposed inside the washing machine main body 1a, and is capable of storing washing water therein. As shown in FIG. 1, the outer peripheral surface 3a of the outer tub 3 is provided with an acceleration sensor 12 capable of detecting acceleration in three directions, for example, the lateral direction, the vertical direction, and the longitudinal direction. In this embodiment, the acceleration sensor 12 is a three-axis sensor capable of detecting acceleration in the left-right direction, the up-down direction, and the front-rear direction. The arrangement of the acceleration sensor 12 is not limited as long as the acceleration of the drum 2 or the outer tub 3 can be detected. Further, the outer tub 3 is connected with a discharge path 3b capable of discharging washing water to the outside. The discharge passage 3b is provided with a discharge valve 3c that can be opened and closed.

The drum 2 is a cylindrical member with a bottom that is arranged coaxially with the outer tub 3 inside the outer tub 3 and is rotatably supported. The drum 2 can accommodate laundry inside and has a large number of water passage holes on its wall surface. As shown in FIG. 1, the driving device 20 rotates the pulley 15 and the belt 15a by the motor 10, and rotates the driving shaft 17 extending toward the bottom 2c of the drum 2 to apply driving force to the drum 2. and rotate the drum 2.

FIG. 2 is a control block diagram of the washing machine 1 of this embodiment. As shown in FIG. 2, the control unit 50 of the washing machine 1 is composed of, for example, a microcomputer. and a RAM for temporarily storing data and the like used when performing the operation. The operation of the washing machine 1 is controlled by this controller 50 . The motor 10 and the acceleration sensor 12 are connected to the controller 50 .

The control unit 50 has a motor output calculation unit 51 , an acceleration output calculation unit 52 , an output difference calculation unit 53 , a dehydration acceleration determination unit 54 , a failure determination unit 55 and a motor control unit 56 .

After dehydration is started, the motor output calculation unit 51 calculates the difference between the current value of the motor 10 at the current time and the current value of the motor 10 when the rotation speed of the drum 2 is 400 rpm as the motor output in the medium speed range. calculate. In this embodiment, the output data from the motor 10 is processed by a microcomputer. If the analog input port of the microcomputer has a 10-bit AD conversion function, the current value 0 to 8A of the motor 10 is resolved into 1024 pieces, and the motor output is digitized as a microcomputer value. A method of calculating the difference between the current value of the motor 10 as the motor output and the current value of the motor 10 when the rotation speed of the drum 2 is 400 rpm will be described with reference to FIG.

<Step S1>
In step S1, the controller 50 measures the current value of the motor 10 when the rotation speed of the drum 2 is 400 rpm, and stores the current value. Therefore, in the dewatering process, the current value of the motor 10 is measured when the rotation speed of the drum 2 reaches 400 rpm.

<Step S2>
In step S2, the controller 50 acquires the current value of the motor 10, and calculates the difference between the current value of the motor 10 and the current value of the motor 10 when the rotation speed of the drum 2 is 400 rpm. The difference in current values corresponds to the magnitude of the load on the motor.

After dehydration is started, the acceleration output calculation unit 52 calculates an acceleration change amount within one rotation period of the drum 2 as an acceleration output in the medium speed region. In this embodiment, the output data from the acceleration sensor 12 is processed by a microcomputer, but if the analog input port of the microcomputer has a 10-bit AD conversion function, the output 0 to 5V of the acceleration sensor 12 is resolved into 1024 pieces, and the acceleration The output is digitized as a microcomputer value. A method of calculating the acceleration change amount within one rotation period of the drum 2 as the acceleration output will be described with reference to FIGS. 4 and 5. FIG.

<Steps S101, S102>
In step S101, the control unit 50 acquires an acceleration signal from the acceleration sensor 12, and in step S102 performs noise processing using a low-pass filter. FIG. 5 is a graph showing the output of the acceleration sensor 12. As shown in FIG.

<Step S103>
In FIG. 5, the waveform of the acceleration signal from the acceleration sensor 12 is a waveform that has a maximum value (max) and a minimum value (min) and changes periodically. Therefore, in step S103, the controller 50 calculates the amount of change in acceleration during one revolution of the drum 2 based on the difference between the maximum value (max) and the minimum value (min). Since the acceleration signal from the acceleration sensor 12 includes vibrations in three axial directions, the output of the acceleration sensor 12 is an output that reflects vibrations in the left-right direction, the up-down direction, and the front-rear direction.

The output difference calculator 53 calculates an output difference by subtracting the motor output calculated by the motor output calculator 51 from the acceleration output calculated by the acceleration output calculator 52 . In this embodiment, as described above, the motor output and the acceleration output are quantified as microcomputer values, so the output difference is calculated as the difference between the microcomputer values.

When the output difference obtained by subtracting the motor output from the acceleration output is equal to or greater than the first threshold value after the rotational speed of the drum 2 reaches a predetermined rotational speed or more in the dehydration process, the dehydration acceleration determination unit 54 determines whether the drum 2 and the outer tub are separated. 3, it is determined that the rotation speed of the drum 2 can be increased. Further, when the output difference obtained by subtracting the motor output from the acceleration output is smaller than the first threshold, the dehydration acceleration determination unit 54 determines that water remains between the drum and the outer tank, and reduces the rotation speed of the drum 2. It is determined that it is impossible to climb. The first threshold value can be expressed as a continuous linear function of the rotational speed of the drum 2, but the slope or intercept changes as the rotational speed changes, or it is stored in the RAM as a table.

Further, the dehydration acceleration determination unit 54 determines that the rotation speed of the drum 2 cannot be increased because the output difference obtained by subtracting the motor output from the acceleration output is smaller than the first threshold value, and then determines the output obtained by subtracting the motor output from the acceleration output. When the difference becomes equal to or greater than the second threshold, it is determined that the number of rotations of the drum 2 can be increased, assuming that the state in which water remains between the drum 2 and the outer tub 3 has been resolved. In this embodiment, the second threshold is a value greater than the first threshold.

The failure determination unit 55 determines whether or not the acceleration sensor 12 has failed based on the acceleration output based on the acceleration signal from the acceleration sensor 12 . In this embodiment, the failure detection unit 55 determines that the acceleration sensor 12 is out of order when the acceleration output of the acceleration sensor 12 does not change when the rotation speed of the drum 2 increases. The case where the acceleration output of the acceleration sensor 12 does not change includes the case where the acceleration output of the acceleration sensor 12 is 0 and the case where the amount of change in the acceleration output of the acceleration sensor 12 is less than or equal to a predetermined amount.

The motor control unit 56 controls the rotation speed of the drum 2 by changing the motor current based on the determination by the dehydration acceleration determination unit 54 . In the dehydration process, the motor control unit 56 of this embodiment changes the motor current so as to increase the rotation speed of the drum 2 at a predetermined increase speed corresponding to the current rotation speed of the drum 2 . Specifically, the motor control unit 56 changes the motor current so that the rotation speed of the drum 2 is increased by 20 rpm per second until the rotation speed of the drum 2 reaches 400 rpm, and rotates until the rotation speed of the drum 2 reaches 600 rpm. The motor current is changed so as to increase the rotation speed by 5 rpm per second, and the motor current is changed so that the rotation speed of the drum 2 is increased by 20 rpm per second until the rotation speed of the drum 2 reaches 800 rpm. Further, in the dewatering process, when the rotation speed of the drum 2 reaches the target rotation speed (for example, 800 rpm), the motor control unit 56 continues the dehydration process, and after a predetermined dehydration time elapses, the dehydration process is started. exit.

Specifically, when the dehydration acceleration determination unit 54 determines that the rotation speed of the drum 2 can be increased after the rotation speed of the drum 2 reaches or exceeds a predetermined rotation speed in the dehydration process, the motor control unit 56 The current of the motor 10 is increased so that the rotation speed of 2 increases.

Further, when the dehydration acceleration determination unit 54 determines that the rotation speed of the drum 2 cannot be increased after the rotation speed of the drum 2 reaches or exceeds the predetermined rotation speed in the dehydration process, the motor control unit 56 rotates the drum 2. The current of the motor 10 is not changed so that the rotation speed is maintained for a predetermined time.

Further, in the dehydration process, after the output difference obtained by subtracting the motor output from the acceleration output becomes smaller than the first threshold, the motor control unit 56 causes the output difference obtained by subtracting the motor output from the acceleration output to become equal to or larger than the second threshold, When the dehydration acceleration determining unit 54 determines that the rotation speed of the drum 2 can be increased, the current of the motor 10 is increased so that the rotation speed of the drum 2 increases.

That is, the washing machine 1 of the present embodiment includes a cylindrical drum 2 with a bottom that is rotatable about an axis, and a motor 10 that rotates the drum 2 via a drive shaft 17 protruding from the bottom of the drum 2. and an acceleration sensor 12 for detecting the acceleration of the drum 2, and a first output difference obtained by subtracting the output of the motor 10 from the output of the acceleration sensor 12 after the number of revolutions of the drum 2 reaches or exceeds a predetermined number of revolutions in the dewatering process. When the output difference is smaller than the first threshold, the dehydration acceleration determination section 54, which is a determination means for determining that the rotation speed of the drum 2 cannot be increased, and the motor 10 is controlled based on the determination by the dehydration acceleration determination section 54. and a motor control unit 56 as control means.

As a result, in the washing machine 1 of the present embodiment, water flows between the drum 2 and the outer tub 3 based on the fact that the output difference obtained by subtracting the output of the motor 10 from the output of the acceleration sensor 12 is smaller than the first threshold value. The remaining state is detected, and the number of revolutions of the drum 2 is prevented from increasing. Therefore, it is possible to prevent abnormal noise from being generated by rotating the drum 2 while water remains between the drum 2 and the outer tub 3 .

Next, the operation of washing machine 1 when determining whether or not acceleration sensor 12 is out of order will be described with reference to FIG.

<Step S201>
In step S201, when the operation of washing machine 1 is started, controller 50 repeatedly determines whether or not the acceleration output based on the acceleration signal from acceleration sensor 12 is zero. If the output of the acceleration sensor 12 is not 0, the process proceeds to step S202.

<Step S202>
In step S202, the controller 50 determines whether or not the amount of change in the acceleration output based on the acceleration signal from the acceleration sensor 12 is equal to or less than a predetermined amount when the rotation speed of the drum 2 increases. The predetermined amount is for judging whether or not the acceleration output based on the acceleration signal from the acceleration sensor 12 increases appropriately as the rotation speed of the drum 2 increases. If the amount of change in acceleration output is not equal to or less than the predetermined amount, the process proceeds to step S203.

<Step S203>
In step S203, the control unit 50 determines that the acceleration sensor 12 is not out of order, and continues the operation of the washing machine 1 using both the motor output and the acceleration output.

<Step S204>
If the acceleration output of the acceleration sensor 12 is 0 in step S201, and if the amount of change in the acceleration output is equal to or less than the predetermined amount in step S202, the control unit 50 proceeds to step S204, and determines that the acceleration sensor 12 has failed. The washing machine 1 continues to operate using only the motor output without using the acceleration output.

As described above, in the washing machine 1 of the present embodiment, when the acceleration sensor 12 fails, the washing machine 1 continues to operate using only the motor output. Therefore, in this case, in the washing machine 1 of this embodiment, it is not possible to detect the state in which water remains between the drum 2 and the outer tub 3 based on both the motor output and the acceleration output.

That is, in the washing machine 1 of the present embodiment, the dehydration acceleration determination unit 54 determines that the rotation speed of the drum 2 cannot be increased when the acceleration output of the acceleration sensor 12 does not change when the rotation speed of the drum 2 increases. .

Accordingly, in the washing machine 1 of the present embodiment, the output of the acceleration sensor 12 does not change when the rotation speed of the drum 2 increases, so there is a high possibility that the acceleration sensor 12 is out of order. Therefore, based on the output of the acceleration sensor 12 at that time, it is possible to prevent the number of revolutions of the drum 2 from increasing while water remains between the drum 2 and the outer tub 3 .

Next, the operation of the washing machine 1 in the dewatering process will be described with reference to FIG.

<Steps S301, S302>
In step S301, when the dewatering process is started, the controller 50 controls the motor 10 to drive the drum 2 to rotate. In step S302, the control unit 50 repeatedly determines whether or not the rotation speed of the drum 2 has reached a predetermined rotation speed (for example, 400 rpm) (whether the rotation speed of the drum 2 is in the middle speed range). If the number of rotations of the drum 2 reaches the predetermined number of rotations, the process proceeds to step S303.

<Step S303>
In step S<b>303 , the control unit 50 calculates the amount of change in acceleration within one rotation period of the drum 2 as the acceleration output of the acceleration sensor 12 based on the acceleration signal from the acceleration sensor 12 .

<Step S304>
In step S304, the control unit 50 detects the current value of the motor 10 at the present time, and outputs the current value of the motor 10 at the present time to the current value of the motor 10 when the rotation speed of the drum 2 is 400 rpm. Calculate the difference.

<Step S305>
In step S305, based on the acceleration output and motor output calculated in steps S303 and S304, the control unit 50 determines whether or not the output difference obtained by subtracting the motor output from the acceleration output is smaller than or equal to a first threshold. .

<Step S306>
In step S305, if the output difference obtained by subtracting the motor output from the acceleration output is equal to or greater than the first threshold (S305: NO), the process proceeds to step S306, and the control unit 50 increases the rotation speed of the drum 2 to perform dehydration. To accelerate. In step S306, the controller 50 increases the rotational speed of the drum 2 at a predetermined rising speed corresponding to the current rotational speed of the drum 2. After the predetermined rising time elapses, the process proceeds to step S307.

<Steps S307, S308>
In step S307, it is determined whether or not the rotation speed of the drum 2 has reached the target rotation speed. When the number of rotations of the drum 2 reaches the target number of rotations (S307: YES), in step S308, the control unit 50 continues the dehydration process, and after a predetermined dehydration time has passed, the dehydration process is started. finish. In step S307, when the rotation speed of the drum 2 has not reached the target rotation speed (S307: NO), the process proceeds to step S303.

<Step S309>
In step S305, if the output difference obtained by subtracting the motor output from the acceleration output is smaller than the first threshold (S305: YES), the process proceeds to step S309. In step S309, the controller 50 determines that water remains between the drum 2 and the outer tub 3 because the output difference obtained by subtracting the motor output from the acceleration output is smaller than the first threshold, and accelerates the dehydration. is stopped, and the rotation speed of the drum 2 is maintained for a predetermined time. By continuing the operation while maintaining the number of revolutions of the drum 2 for a predetermined time, the water is drained between the drum 2 and the outer tank 3, and the water remains between the drum 2 and the outer tank 3. may be canceled. After that, the process proceeds to step S310.

That is, in the washing machine 1 of the present embodiment, when the dehydration acceleration determination unit 54 determines that the rotation speed of the drum 2 cannot be increased, the motor control unit 56 controls the rotation speed of the drum 2 to be maintained for a predetermined time. , controls the motor 10 .

Accordingly, in the washing machine 1 of the present embodiment, when the dehydration acceleration determination unit 54 determines that the rotation speed of the drum 2 cannot be increased, the rotation speed of the drum 2 is maintained for a predetermined time. is stopped each time, the operating efficiency of the washing machine 1 is improved.

<Step S310>
In step S310, the control unit 50 calculates the acceleration output of the acceleration sensor 12 based on the acceleration signal from the acceleration sensor 12 after the number of rotations of the drum 2 is maintained for a predetermined time in step S309. The method of calculating the acceleration output is the same as in step S303.

<Step S311>
In step S311, the control unit 50 detects the current value of the motor 10 after the rotation speed of the drum 2 is maintained for a predetermined time in step S309, and calculates the motor output. The method of calculating the motor output is the same as in step S304.

<Step S312>
In step S312, based on the acceleration output and motor output calculated in steps S310 and S311, the control unit 50 determines whether or not the output difference obtained by subtracting the motor output from the acceleration output is greater than or equal to the second threshold. If the output difference is equal to or greater than the second threshold (S312: YES), the control unit 50 determines that the state in which water remains between the drum 2 and the outer tub 3 has been resolved, and proceeds to step S306. Increase the rotation speed to accelerate dehydration. If the output difference is smaller than the second threshold (S312: NO), the control unit 50 determines that the state in which water remains between the drum 2 and the outer tub 3 has not been resolved, and proceeds to step S309 to 2 is maintained for a predetermined period of time.

That is, in the washing machine 1 of the present embodiment, the dehydration acceleration determination unit 54, which is the determination means, determines that the rotational speed of the drum cannot be increased, and then outputs the first output obtained by subtracting the output of the motor 10 from the output of the acceleration sensor 12. When the output difference, which is the difference, becomes equal to or greater than the second threshold, it is determined that the rotation speed of the drum 2 can be increased.

As a result, in the washing machine 1 of the present embodiment, when the output difference obtained by subtracting the output of the motor 10 from the output of the acceleration sensor 12 is equal to or greater than the second threshold value, water is detected between the drum 2 and the outer tub 3. It is detected that the state of remaining is eliminated, and the rotation speed of the drum 2 is increased. Therefore, when the state in which water remains between the drum 2 and the outer tub 3 is eliminated, the rotation speed of the drum 2 can be increased to accelerate dehydration.

In the washing machine 1 of this embodiment, the second threshold is greater than the first threshold. As a result, in the washing machine 1 of the present embodiment, the second threshold for detecting that the state in which water remains between the drum 2 and the outer tub 3 has been resolved is is greater than the first threshold value for detecting that water remains in the drum 2, when the state in which water remains between the drum 2 and the outer tank 3 is reliably resolved, the number of revolutions of the drum 2 can be increased to accelerate dehydration.

(Second embodiment)
A second embodiment of the present invention will be described in detail with reference to FIGS. 8 and 9. FIG.

The main difference between the washing machine of this embodiment and the washing machine 1 of the first embodiment is that, in the first embodiment, whether or not to accelerate dehydration is determined based on the output difference obtained by subtracting the motor output from the acceleration output. On the other hand, in the present embodiment, it is determined whether or not to accelerate dehydration based on the output ratio obtained by dividing the acceleration output by the motor output. In the configuration of the washing machine of this embodiment, the description of the configuration similar to that of the washing machine 1 of the first embodiment is omitted.

As shown in FIG. 8, the control unit 150 of the washing machine of this embodiment includes a motor output calculation unit 51, an acceleration output calculation unit 52, an output ratio calculation unit 153, a dehydration acceleration determination unit 154, and a failure determination unit. 55 and a motor control unit 56 .

The output ratio calculator 153 calculates an output ratio (acceleration output/motor output) by dividing the acceleration output calculated by the acceleration output calculator 52 by the motor output calculated by the motor output calculator 51 . In this embodiment, as in the first embodiment, the motor output and the acceleration output are quantified as microcomputer values, so the output ratio is calculated as the ratio of the microcomputer values.

If the output ratio obtained by dividing the acceleration output by the motor output is equal to or greater than the first threshold after the rotational speed of the drum 2 reaches or exceeds a predetermined rotational speed in the dehydration process, the dehydration acceleration determination unit 154 determines whether the drum 2 and the outer tub are separated. 3, it is determined that the rotation speed of the drum 2 can be increased. Further, when the output ratio obtained by dividing the acceleration output by the motor output is smaller than the first threshold value, the dehydration acceleration determination unit 154 determines that water remains between the drum and the outer tank, and reduces the rotation speed of the drum 2. It is determined that it is impossible to climb. The first threshold value can be expressed as a continuous linear function of the rotational speed of the drum 2, but the slope or intercept changes as the rotational speed changes, or it is stored in the RAM as a table.

Further, since the output ratio obtained by dividing the acceleration output by the motor output is smaller than the first threshold value, the dehydration acceleration determination unit 154 determines that the number of revolutions of the drum 2 cannot be increased. When the ratio becomes equal to or greater than the second threshold, it is determined that the number of revolutions of the drum 2 can be increased, assuming that the state in which water remains between the drum 2 and the outer tub 3 has been resolved. In this embodiment, the second threshold is a value greater than the first threshold.

That is, the washing machine of this embodiment includes a cylindrical drum 2 with a bottom that is rotatable around an axis, and a motor 10 that rotates the drum 2 via a drive shaft 17 protruding from the bottom of the drum 2. , an acceleration sensor 12 for detecting the acceleration of the drum 2, and a first output ratio obtained by dividing the output of the acceleration sensor 12 by the output of the motor 10 after the rotation speed of the drum 2 reaches a predetermined rotation speed or more in the dewatering process. When a certain output ratio is smaller than the first threshold, the dehydration acceleration determination section 154, which is a determination means for determining that the rotation speed of the drum 2 cannot be increased, and the control of controlling the motor 10 based on the determination by the dehydration acceleration determination section 154. and a motor control unit 56 as means.

As a result, in the washing machine of the present embodiment, water remains between the drum 2 and the outer tub 3 based on the fact that the output ratio obtained by dividing the output of the acceleration sensor 12 by the output of the motor 10 is smaller than the first threshold value. It is detected that the drum 2 is in a state of being stuck, and the number of revolutions of the drum 2 is prevented from increasing. Therefore, it is possible to prevent abnormal noise from being generated by rotating the drum 2 while water remains between the drum 2 and the outer tub 3 .

Next, the operation of the washing machine of this embodiment in the dewatering process will be described with reference to FIG. The description of steps S401 to S404 in FIG. 9 is the same as the description of steps S301 to S304 in FIG. 7, so the description thereof will be omitted.

<Step S405>
In step S405, the control unit 150 determines whether or not the output ratio obtained by dividing the acceleration output by the motor output is smaller than or equal to the first threshold.

<Step S406>
In step S405, if the output ratio obtained by dividing the acceleration output by the motor output is greater than or equal to the first threshold (S405: NO), the process proceeds to step S406, and the control unit 150 increases the rotation speed of the drum 2 to perform dehydration. To accelerate. In step S406, the controller 150 increases the rotation speed of the drum 2 at a predetermined rate of increase corresponding to the current rotation speed of the drum 2. After the predetermined increase time elapses, the process proceeds to step S407.

<Steps S407, S408>
In step S407, it is determined whether or not the rotation speed of the drum 2 has reached the target rotation speed. When the number of revolutions of the drum 2 reaches the target number of revolutions (S407: YES), in step S408, the control unit 150 continues the dehydration process, and after a predetermined dehydration time has passed, the dehydration process is started. finish. In step S407, when the rotation speed of the drum 2 has not reached the target rotation speed (S407: NO), the process proceeds to step S403.

<Step S409>
In step S405, when the output ratio obtained by dividing the acceleration output by the motor output is smaller than the first threshold (S405: YES), the process proceeds to step S409. In step S409, the control unit 150 determines that water remains between the drum 2 and the outer tub 3 because the output ratio obtained by dividing the acceleration output by the motor output is smaller than the first threshold, and accelerates dehydration. is stopped, and the rotation speed of the drum 2 is maintained for a predetermined time. By continuing the operation while maintaining the number of revolutions of the drum 2 for a predetermined time, the water is drained between the drum 2 and the outer tank 3, and the water remains between the drum 2 and the outer tank 3. may be canceled. After that, the process proceeds to step S410.

That is, in the washing machine of the present embodiment, when the dehydration acceleration determination unit 154 determines that the rotation speed of the drum 2 cannot be increased, the motor control unit 56 controls the motor 10 so that the rotation speed of the drum 2 is maintained. to control.

Accordingly, in the washing machine of the present embodiment, when the dehydration acceleration determination unit 154 determines that the rotation speed of the drum 2 cannot be increased, the rotation speed of the drum 2 is maintained for a predetermined time. The operation efficiency of the washing machine 1 is improved as compared with the case of stopping each time.

<Step S410>
At step S410, the control unit 150 calculates the acceleration output of the acceleration sensor 12 based on the acceleration signal from the acceleration sensor 12 after the rotation speed of the drum 2 is maintained for a predetermined time at step S409. The method of calculating the acceleration output is the same as in step S403.

<Step S411>
In step S411, the control unit 150 detects the current value of the motor 10 after the rotation speed of the drum 2 is maintained for a predetermined time in step S409, and calculates the motor output. The method of calculating the motor output is the same as in step S404.

<Step S412>
In step S412, based on the acceleration output and motor output calculated in steps S410 and S411, the control unit 150 determines whether or not the output ratio obtained by dividing the acceleration output by the motor output is greater than or equal to the second threshold. In step S412, if the output ratio obtained by dividing the acceleration output by the motor output is equal to or greater than the second threshold (S412: YES), the control unit 150 eliminates the state in which water remains between the drum 2 and the outer tub 3. Assuming that, the process proceeds to step S406 to increase the rotational speed of the drum 2 to accelerate dehydration. In step S412, when the output ratio obtained by dividing the acceleration output by the motor output is smaller than the second threshold (S412: NO), the control unit 150 determines that the state in which water remains between the drum 2 and the outer tub 3 is resolved. If not, the process proceeds to step S409 to continue the state in which the number of rotations of the drum 2 is maintained for a predetermined time.

That is, in the washing machine of the present embodiment, the dehydration acceleration determination unit 154, which is the determination means, can increase the rotation speed of the drum 2 when the output ratio obtained by dividing the acceleration output by the motor output becomes equal to or greater than the second threshold. I judge.

As a result, in the washing machine of the present embodiment, water flows between the drum 2 and the outer tub 3 based on the fact that the output ratio obtained by dividing the output of the acceleration sensor 12 by the output of the motor 10 is greater than or equal to the second threshold. It is detected that the remaining state is eliminated, and the rotation speed of the drum 2 is increased. Therefore, when the state in which water remains between the drum 2 and the outer tub 3 is eliminated, the rotation speed of the drum 2 can be increased to accelerate dehydration.

(Third embodiment)
A third embodiment of the present invention will be described in detail with reference to FIGS. 10 and 11. FIG.

The main difference between the washing machine of the present embodiment and the washing machine of the first embodiment is that, in the first embodiment, it is determined whether or not to accelerate dehydration based on the output difference obtained by subtracting the motor output from the acceleration output. On the other hand, in the present embodiment, it is determined whether or not dehydration is to be accelerated by determining the motor output and the acceleration output respectively. In the configuration of the washing machine of this embodiment, the description of the configuration similar to that of the washing machine 1 of the first embodiment is omitted.

As shown in FIG. 10, the control unit 250 of the washing machine of this embodiment includes a motor output calculation unit 51, an acceleration output calculation unit 52, a dehydration acceleration determination unit 254, a failure determination unit 55, and a motor control unit 56. and

The dehydration acceleration determination unit 254 detects vibration of the drum 2 when the motor output is smaller than the motor threshold and the acceleration output is smaller than the acceleration threshold after the number of revolutions of the drum 2 reaches or exceeds the predetermined number of revolutions in the dehydration process. It is determined that the rotational speed of the drum 2 can be increased because it is small and water does not remain between the drum 2 and the outer tub 3 . Further, when the motor output is equal to or greater than the motor threshold value and the acceleration output is smaller than the acceleration threshold value, the dehydration acceleration determination unit 254 determines that water remains between the drum and the outer tank even though the vibration of the drum 2 is small. It is determined that the rotational speed of the drum 2 cannot be increased.

Further, the dehydration acceleration determination unit 254 determines that the rotation speed of the drum 2 cannot be increased because the motor output is equal to or greater than the motor threshold and the acceleration output is less than the acceleration threshold. , when the motor output becomes smaller than the motor threshold value, it is determined that the number of revolutions of the drum 2 can be increased, assuming that the state in which water remains between the drum 2 and the outer tub 3 is resolved.

Further, when the acceleration output is equal to or greater than the acceleration threshold, the dehydration acceleration determination unit 254 determines that the rotation speed of the drum 2 cannot be increased because the vibration of the drum 2 is large.

That is, the washing machine of this embodiment includes a cylindrical drum 2 with a bottom that is rotatable around an axis, and a motor 10 that rotates the drum 2 via a drive shaft 17 protruding from the bottom of the drum 2. , an acceleration sensor 12 for detecting the acceleration of the drum 2, and an output of the motor 10 that is equal to or higher than the motor threshold value and an output of the acceleration sensor 12 that is equal to or higher than the acceleration threshold after the number of revolutions of the drum 2 reaches or exceeds a predetermined number of revolutions in the dehydration process. A dehydration acceleration determination unit 254, which is a determination means for determining that the rotation speed of the drum 2 cannot be increased, and a motor control unit, which is a control means for controlling the motor 10 based on the determination by the dehydration acceleration determination unit 254 56.

As a result, in the washing machine of the present embodiment, water remains between the drum 2 and the outer tub 3 based on the fact that the output of the motor 10 is greater than or equal to the motor threshold value and the output of the acceleration sensor 12 is less than the acceleration threshold value. This state is detected, and the rotational speed of the drum 2 is prevented from increasing. Therefore, in the dehydration process, it is possible to prevent the occurrence of abnormal noise caused by rotating the drum 2 with water remaining between the drum 2 and the outer tub 3 .

Next, the operation of the dewatering process of the washing machine of this embodiment will be described with reference to FIG. 11 . The description of steps S501 to S504 in FIG. 11 is the same as the description of steps S301 to S304 in FIG. 7, so the description thereof will be omitted.

<Steps S505, S506, S507>
In step S505, the control unit 250 determines whether or not the motor output is smaller than the motor threshold. If the motor output is smaller than the motor threshold (S505: YES), the process proceeds to step S506 to determine whether the acceleration output is smaller than the acceleration threshold. In step S506, if the acceleration output is smaller than the acceleration threshold (S506: YES), the process proceeds to step S507 to increase the rotational speed of the drum 2 to accelerate the dehydration. In step S507, the controller 250 increases the rotation speed of the drum 2 at a predetermined rate of increase corresponding to the current rotation speed of the drum 2. After the predetermined increase time elapses, the process proceeds to step S508.

<Steps S508, S509>
In step S508, it is determined whether or not the rotation speed of the drum 2 has reached the target rotation speed. When the rotation speed of the drum 2 reaches the target rotation speed (S508: YES), in step S509, the control unit 250 continues the dehydration process, and after a predetermined dehydration time elapses, the dehydration process is started. finish. In step S508, if the rotation speed of the drum 2 has not reached the target rotation speed (S508: NO), the process proceeds to step S503.

<Step S510>
In step S506, if the acceleration output is equal to or greater than the acceleration threshold value (S506: NO), it means that the laundry is heavily biased, so the process proceeds to step S510 to stop dehydration.

That is, in the washing machine of this embodiment, the determining means 254 determines that the rotation speed of the drum 2 should be stopped when the acceleration output is equal to or greater than the acceleration threshold.

Thus, in the washing machine of the present embodiment, based on the fact that the output of the acceleration sensor 12 is equal to or greater than the acceleration threshold value, it is detected that the laundry is heavily biased, and the rotation speed of the drum 2 is prevented from increasing. . Therefore, in the dehydration process, it is possible to prevent the occurrence of vibration and noise caused by increasing the number of rotations of the drum 2 when the laundry is largely uneven.

<Steps S511 and S512>
In step S505, if the motor output is greater than or equal to the motor threshold (S505: NO), the process proceeds to step S511 to determine whether the acceleration output is less than the acceleration threshold. If the acceleration output is smaller than the acceleration threshold value (S511: YES), it is determined that water remains between the drum 2 and the outer tub 3, and the process proceeds to step S512 to stop dewatering acceleration and rotate the drum 2. Maintain the number for a predetermined time. By continuing the operation while maintaining the number of revolutions of the drum 2 for a predetermined time, the water is drained between the drum 2 and the outer tank 3, and the water remains between the drum 2 and the outer tank 3. may be canceled. In step S511, if the acceleration output is greater than or equal to the acceleration threshold value (S511: NO), it means that the laundry is heavily biased, so the process proceeds to step S510 to stop dehydration.

That is, in the washing machine of the present embodiment, when the dehydration acceleration determination unit 254 determines that the rotation speed of the drum 2 cannot be increased, the motor control unit 56 maintains the rotation speed of the drum 2 for a predetermined time. Control the motor 10 .

As a result, in the washing machine of the present embodiment, when the dehydration acceleration determining unit 254 determines that the rotation speed of the drum 2 cannot be increased, the rotation speed of the drum 2 is maintained for a predetermined period of time. The operating efficiency of the washing machine is improved compared to the case where the washing machine is stopped each time.

<Step S513>
In step S513, the controller 250 calculates the acceleration output of the acceleration sensor 12 based on the acceleration signal from the acceleration sensor 12 after the number of revolutions of the drum 2 is maintained for a predetermined time in step S512. The method of calculating the acceleration output is the same as in step S503.

<Steps S514, S515>
In step S514, the control unit 250 determines whether or not the acceleration output calculated in step S513 is smaller than the acceleration threshold. If the acceleration output is smaller than the acceleration threshold (S514: YES), in step S515, the controller 250 detects the current value of the motor 10 after the rotation speed of the drum 2 is maintained for a predetermined time in step S512, and detects the motor output. to calculate The method of calculating the motor output is the same as in step S504. In step S514, if the acceleration output is greater than or equal to the acceleration threshold value (S514: NO), it means that the laundry is heavily biased, so the process proceeds to step S510 to stop dehydration.

<Step S516>
At step S516, the control unit 250 determines whether the motor output calculated at step S515 is smaller than the motor threshold value. If the motor output is smaller than the motor threshold value (S516: YES), it is determined that the state in which water remains between the drum 2 and the outer tub 3 has been resolved, and the process proceeds to step S507 to increase the rotation speed of the drum 2, accelerate dehydration; In step S516, if the motor output is equal to or greater than the motor threshold value (S516: NO), the control unit 250 determines that the state in which water remains between the drum 2 and the outer tub 3 has not been resolved, and proceeds to step S512. Then, the state in which the number of revolutions of the drum 2 is maintained for a predetermined time is continued.

That is, in the washing machine of the present embodiment, after the dehydration acceleration determination unit 254, which is the determination means, determines that the rotation speed of the drum cannot be increased, the output of the motor 10 is becomes smaller than the motor threshold value, it is determined that the rotation speed of the drum 2 can be increased.

As a result, in the washing machine of this embodiment, when the output of the acceleration sensor 12 is smaller than the acceleration threshold and the output of the motor 10 becomes smaller than the motor threshold, It is detected that the water remaining state is eliminated, and the rotation speed of the drum 2 is increased. Therefore, when the state in which water remains between the drum 2 and the outer tub 3 is eliminated, the rotation speed of the drum 2 can be increased to accelerate dehydration.

Although the embodiments of the present invention have been described above, the specific configuration of each unit is not limited to the above-described embodiments.

For example, in the above embodiment, when the dehydration acceleration determination unit determines that the rotation speed of the drum 2 cannot be increased, the motor 10 is controlled so that the rotation speed of the drum 2 is maintained. The motor 10 may be controlled such that . In the above embodiment, the first threshold and the second threshold are different values, but the first threshold and the second threshold may be the same. In the third embodiment, the dehydration acceleration determination means 254 stops dehydration when the output of the acceleration sensor is equal to or higher than the acceleration threshold value, assuming that the laundry is highly biased. Alternatively, the rotation speed of the drum 2 may be decreased.

In the above embodiment, the motor output calculation unit 51 calculates the difference between the current value of the motor 10 and the current value of the motor 10 when the rotation speed of the drum 2 is 400 rpm. The method of calculating the output is not limited to this. For example, the motor output calculator 51 may calculate the difference between the current value of the motor 10 at the current time and the current value of the motor 10 when the rotation speed of the drum 2 is other than 400 rpm.

In the above embodiment, the drum 2 is configured to be rotatable about an axis extending in the horizontal direction. good. Also, the drum 2 may be configured to be rotatable around an axis extending in the vertical direction.

In the first embodiment, the determining means 54 determines whether or not to increase the rotation speed of the drum 2 based on the first output difference obtained by subtracting the output of the motor 10 from the output of the acceleration sensor 12. 54 may determine whether or not to increase the rotation speed of the drum 2 based on a second output difference obtained by subtracting the output of the acceleration sensor 12 from the output of the motor 10 . Note that the first threshold value and the second threshold value are set to different values when determining based on the first output difference and when determining based on the second output difference. In the second embodiment, the determining means 154 determines whether or not to increase the rotational speed of the drum 2 based on the first output ratio obtained by dividing the output of the acceleration sensor 12 by the output of the motor 10. 154 may determine whether or not to increase the rotation speed of the drum 2 based on a second output ratio obtained by dividing the output of the motor 10 by the output of the acceleration sensor 12 . Note that the first threshold value and the second threshold value are set to different values when determining based on the first output ratio and when determining based on the second output ratio.

Other configurations can also be modified in various ways without departing from the gist of the present invention.

1 washing machine 2 drum 10 motor 12 acceleration sensor 17 drive shaft 54, 154, 254 dehydration acceleration determination section (determination means)
56 motor control unit (control means)

Claims (11)

a bottomed cylindrical drum configured to be rotatable around an axis;
a motor that rotationally drives the drum via a drive shaft protruding from the bottom of the drum;
an acceleration sensor that detects acceleration of the drum;
A first output difference obtained by subtracting the output of the motor from the output of the acceleration sensor is smaller than a first threshold after the number of rotations of the drum reaches or exceeds a predetermined number of rotations in the dehydration process, or the output of the motor. determining means for determining that the rotation speed of the drum cannot be increased when a second output difference obtained by subtracting the output of the acceleration sensor from the second output difference is equal to or greater than a first threshold value;
and control means for controlling the motor based on the determination by the determination means.,
The output of the motor is a numerical value obtained by AD-converting the difference between the current value of the motor at the present time and the current value of the motor when the number of rotations of the drum is the predetermined number of rotations,
The output of the acceleration sensor is a numerical value obtained by AD-converting the amount of change in acceleration within one rotation period of the drum. A washing machine characterized by: When the first output difference becomes equal to or greater than a second threshold value after determining that the rotational speed of the drum cannot be increased, or when the second output difference becomes smaller than a second threshold value. 2. The washing machine according to claim 1, further comprising determining that the number of revolutions of said drum can be increased. 3. The washing machine according to claim 2, wherein the second threshold for the first output difference is greater than the first threshold, or the second threshold for the second output difference is less than the first threshold. . a bottomed cylindrical drum configured to be rotatable around an axis;
a motor that rotationally drives the drum via a drive shaft protruding from the bottom of the drum;
an acceleration sensor that detects acceleration of the drum;
A first output ratio obtained by dividing the output of the acceleration sensor by the output of the motor is smaller than a first threshold after the number of rotations of the drum reaches a predetermined number of rotations or more in the dehydration process, or the output of the motor. is divided by the output of the acceleration sensor, and if a second output ratio is equal to or greater than a first threshold, a determination means for determining that the number of rotations of the drum cannot be increased;
and control means for controlling the motor based on the determination by the determination means.,
The output of the motor is a numerical value obtained by AD-converting the difference between the current value of the motor at the present time and the current value of the motor when the number of rotations of the drum is the predetermined number of rotations,
The output of the acceleration sensor is a numerical value obtained by AD-converting the amount of change in acceleration within one rotation period of the drum. A washing machine characterized by: When the first output ratio becomes equal to or greater than a second threshold value after determining that the rotational speed of the drum cannot be increased, or when the second output ratio becomes smaller than a second threshold value. 5. The washing machine according to claim 4, wherein it is further determined that the number of revolutions of said drum can be increased. 6. The washing machine according to claim 5, wherein the second threshold for the first output ratio is greater than the first threshold, or the second threshold for the second output ratio is less than the first threshold. . a bottomed cylindrical drum configured to be rotatable around an axis;
a motor that rotationally drives the drum via a drive shaft protruding from the bottom of the drum;
an acceleration sensor that detects acceleration of the drum;
After the number of revolutions of the drum reaches a predetermined number of revolutions or more in the dewatering process, if the output of the motor is equal to or greater than the motor threshold and the output of the acceleration sensor is smaller than the acceleration threshold, the number of revolutions of the drum cannot be increased. and a determination means for determining
and control means for controlling the motor based on the determination by the determination means.,
The output of the motor is a numerical value obtained by AD-converting the difference between the current value of the motor at the present time and the current value of the motor when the number of rotations of the drum is the predetermined number of rotations,
The output of the acceleration sensor is a numerical value obtained by AD-converting the amount of change in acceleration within one rotation period of the drum. A washing machine characterized by: After determining that the rotational speed of the drum cannot be increased, the judging means detects the rotational speed of the drum when the output of the acceleration sensor is smaller than the acceleration threshold value and the output of the motor becomes smaller than the motor threshold value. 8. The washing machine according to claim 7, wherein the washing machine determines that the can be raised. 9. The washing machine according to claim 7, wherein, when the output of the acceleration sensor is equal to or greater than the acceleration threshold, the determination means determines that the number of revolutions of the drum cannot be increased or that the rotation of the drum is to be stopped. . 2. The control means controls the motor so that the rotation speed of the drum is maintained for a predetermined time when the determination means determines that the rotation speed of the drum cannot be increased. 10. The washing machine according to any one of 1 to 9. 11. Any one of claims 1 to 10, wherein the determination means determines that the rotation speed of the drum cannot be increased when the output of the acceleration sensor does not change when the rotation speed of the drum increases. Washing machine as described.

Images