JP2004222969A - Drainage control mechanism of washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability by surely responding to opening/closing abnormality of a drain valve, in a washing machine opening/closing the drain valve attached to the bottom part of a water storage tank by motor driving. <P>SOLUTION: The subject drainage control mechanism is provided with a motor drive circuit 8 receiving a motor rotation signal S1 from a control circuit 10 and rotating a rotating shaft 2a of the motor and a detection circuit 9 detecting a fully opened state or closed state of the drain valve and outputting a rotation completion signal S4. A function receiving the rotation completion signal S4 and outputting a motor stop signal S2 is added to the control circuit 10 and a function of receiving the motor stop signal S2 and stopping the rotating shaft 2a of the motor 2 is added to the motor drive circuit 8. A function outputting a motor initialization signal S3, when no rotation completion signal is inputted a prescribed time passed from outputting the motor rotation signal S1, is added to the control circuit 10. A function receiving the motor initialization signal S3 and returning the rotating shaft 2a to the initial position is added to the motor drive circuit 8. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a drainage control device for a washing machine suitable for application to a domestic / business fully automatic washing machine that opens and closes a drainage valve attached to the bottom of a cistern by a motor drive.
[0002]
[Prior art]
When using this type of washing machine, the user may inadvertently switch the operation (washing operation, rinsing operation, dehydration operation), accidentally turn off the power, or if the power is turned off due to a power failure Is also conceivable. In such a case, there is a risk that the motor that drives the drain valve stops unexpectedly and the drain valve opens and closes abnormally, and the subsequent operation may not be performed normally. .
[0003]
Conventionally, as a countermeasure for this abnormality, a switch having a neutral leaf and two leaves is provided, and based on the contact and separation of the neutral leaf and the leaf, when the motor is rotated to open and close the drain valve, A method has been proposed in which the number of rotations of the motor is increased as much as possible to shorten the control time for half rotation, thereby reducing the probability that the open / close state of the drain valve becomes abnormal (for example, see Patent Document 1).
[0004]
[Patent Document 1] Japanese Patent Publication No. 4-36040 (Claims, page 2, right column, lines 32-35)
[0005]
[Problems to be solved by the invention]
However, this method has the following disadvantages.
[0006]
First, even if the control time of the half rotation is shortened, the probability that the drain valve is abnormally opened / closed only decreases, and if the luck is poor, it is impossible to cope with the abnormal opening / closing of the drain valve. It can be said.
[0007]
Secondly, since the neutral leaf and the two leaves must be carefully assembled so as to be in temporary contact each time the open instruction circuit and the close instruction circuit are switched, vigorous productivity is inferior and yield is reduced. I do. Further, since a neutral leaf is required in addition to the two leaves, the number of parts is large, so that not only the cost is increased but also a failure is likely to occur.
[0008]
In view of such circumstances, the present invention can reliably address drainage valve opening and closing abnormalities, improve reliability, increase productivity and yield, reduce costs, and further reduce the frequency of failures. It is an object of the present invention to provide a drainage control device for a washing machine.
[0009]
[Means for Solving the Problems]
First, a first aspect of the present invention is a drainage control device (1) for a washing machine that opens and closes a drainage valve (13) according to the rotation angle of a rotation shaft (2a) of a motor (2). A control circuit (10) for outputting (S1), a motor drive circuit (8) for receiving a motor rotation signal from the control circuit and rotating the rotation axis of the motor, and providing a rotation of the rotation axis of the motor; The control circuit is provided with a detection circuit (9) for detecting a fully open state and a closed state of the drain valve based on the angle and outputting a rotation completion signal (S4) to the control circuit. A function of outputting a motor stop signal (S2) to the motor drive circuit is added to the control circuit, and a function of stopping the rotation axis of the motor in response to the motor stop signal from the control circuit is added to the motor drive circuit. ,motor A function of outputting a motor initialization signal (S3) to the motor drive circuit when the rotation completion signal is not input even after a predetermined time (T) has elapsed since the output of the rotation signal; A function of receiving the motor initialization signal from the control circuit, initializing the motor, and returning the rotation axis to the initial position is added to the motor drive circuit. Here, a geared motor can be cited as a typical example of the motor.
[0010]
By adopting such a configuration, even if the user inadvertently switches the operation during use of the washing machine and the drain valve opens and closes abnormally, the subsequent operation can be performed normally. Even if the user accidentally turns off the power during use of the washing machine or the power is cut off due to a power failure, the drain valve operates so that the opening and closing operation from the closed state is always guaranteed.
[0011]
Further, according to the present invention, a circular cam (3) having a convex portion (3a) formed on a peripheral portion is mounted on a rotating shaft (2a) of the motor (2), and a pair of contact pieces ( 6, 7) are supported so as to be able to freely contact and separate from each other, and one of the contact pieces (7) is brought into contact with the peripheral portion of the circular cam, so that the pair of contact pieces can be brought into contact with and separated from each other as the circular cam rotates. It is configured to detect the fully open state and the closed state of the drain valve (13) based on the detected state. With such a configuration, only a pair of contact pieces is sufficient to detect the fully opened state and the closed state of the drain valve, so that the number of parts is smaller than that of a conventional drain control device that requires a neutral leaf in addition to two leaves. It works to reduce it.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a view showing one embodiment of a drainage control device for a washing machine according to the present invention, wherein (a) is a front view, (b) is a right side view, (c) is a bottom view,
FIG. 2 is a chart showing an input state of an OFF signal and an ON signal,
3A and 3B are views showing the movement of the circular cam, where FIG. 3A is a state diagram at an initial position, FIG. 3B is a state diagram at half rotation (180 °), and FIG. 3C is a state diagram at one rotation (360 °). FIG.
[0013]
As shown in FIG. 1, the drainage control device 1 for a washing machine has a geared motor 2, and a circular cam 3 is mounted on a rotating shaft 2 a of the geared motor 2. A convex portion 3a is formed at a peripheral portion of the circular cam 3 over a half circumference (180 °), and a pair of contact pieces 6 and 7 are disposed on the upper side of the circular cam 3 so as to be able to freely contact and separate from each other. . Here, the upper contact piece 6 is hollow and supported, and the lower contact piece 7 is in contact with the peripheral edge of the circular cam 3. A detection circuit 9 is connected to these contact pieces 6 and 7, and a control circuit 10 is connected to the detection circuit 9. Further, a motor drive circuit 8 is connected to the control circuit 10. The control circuit 10 includes a timer 10a.
[0014]
A pulley 5 is mounted on the rotation shaft 2 a of the geared motor 2, and a pin 12 is eccentrically protruded from the rotation shaft 2 a of the geared motor 2. As shown in FIG. 1B, a drain valve 13 attached to the bottom of the water reservoir 11 is located above the pin 12, and the drain valve 13 includes a valve seat 14 and a valve body 15. . That is, a valve seat 14 is fixed to the bottom of the water reservoir 11, and a valve body 15 is provided below the valve seat 14 so as to be brought into contact with and separated from the valve seat 14 by its vertical movement. Further, the valve body 15 is connected to the pin 12 via a wire 16.
[0015]
Since the drainage control device 1 of the washing machine has the above configuration, the operation when the water in the water tub 11 is discharged from the bottom thereof is as follows.
[0016]
First, as shown in FIG. 3A, the control circuit 10 sends a motor rotation signal S1 to the motor drive circuit 8 in a state where the rotation shaft 2a of the geared motor 2 is at the initial position (position where the rotation angle is 0 °). Then, the motor drive circuit 8 starts energizing the geared motor 2. Then, the rotation shaft 2a of the geared motor 2 starts rotating at a predetermined rotation speed (for example, 5 rpm, 6 rpm, or the like) in a counterclockwise direction (direction of arrow M) from the initial position. As a result, the pulley 5 rotates together with the pin 12 in the same direction, and the valve body 15 is separated from the valve seat 14 by being pulled by the pin 12, so that the drain valve 13 starts to open and the water in the water reservoir 11 is discharged. . At this time, the circular cam 3 also starts rotating in the same direction, but the pair of contact pieces 6 and 7 maintain the open state.
[0017]
Then, when the rotation shaft 2a of the geared motor 2 is rotated by 180 ° and positioned at a half-rotation position (a rotation angle of 180 °), the valve body 15 is pulled down as shown in FIG. Since the pin 12 reaches the bottom dead center, the drain valve 13 is fully opened. At the same time, the lower contact piece 7 is pushed up by the convex portion 3a of the circular cam 3 and comes into contact with the upper contact piece 6 to be short-circuited. Therefore, as shown in FIG. , The rotation completion signal S4 is input from the detection circuit 9 to the control circuit 10. In response to this, the control circuit 10 outputs a motor stop signal S2 to the motor drive circuit 8, and the motor drive circuit 8 cuts off the power supply to the geared motor 2. Then, the rotation shaft 2a of the geared motor 2 stops its rotation, so that the drain valve 13 is kept fully open, and the drain operation is continued.
[0018]
At this time, while the rotating shaft 2a of the geared motor 2 is rotating by 180 ° from the initial position to the half-rotation position, the user may inadvertently switch the operation or cause the drain valve 13 to open and close abnormally. Therefore, in order to cope with this, the control circuit 10 counts the elapsed time from the output of the motor rotation signal S1 by the timer 10a, and adds a little adjustment time α to the normal half rotation time t of the geared motor 2. It is monitored whether or not the rotation completion signal S4 is input before a predetermined time T (= t + α) elapses. For example, when the rotation speed of the geared motor 2 is 5 rpm, the half-rotation time t is 6 seconds. Therefore, if the adjustment time α is 1 second, the predetermined time T is 7 seconds. When the rotation speed of the geared motor 2 is 6 rpm, the half-rotation time t is 5 seconds, so that if the adjustment time α is 1 second, the predetermined time T is 6 seconds.
[0019]
If the rotation completion signal S4 is input before the predetermined time T elapses after the output of the motor rotation signal S1, the control circuit 10 causes the circular cam 3 to rotate normally and the drain valve 13 to operate normally. Judge that it is working. Conversely, if the rotation completion signal S4 is not input after a predetermined time T has elapsed since the output of the motor rotation signal S1, the control circuit 10 stops the rotation of the circular cam 3 halfway due to some abnormality and the drain valve 13 is determined to be in an incompletely opened / closed state, and outputs a motor initialization signal S3 to the motor drive circuit 8. In response to this, the motor drive circuit 8 initializes (initializes) the geared motor 2 and returns the rotary shaft 2a to the initial position. Accordingly, even if the drain valve 13 has an open / close abnormality, the subsequent operation can be performed normally, and the reliability of the drain valve 13 is improved.
[0020]
When the operation of discharging the water from the water reservoir 11 is completed, the control circuit 10 outputs the motor rotation signal S1 to the motor drive circuit 8 again, and the motor drive circuit 8 starts energizing the geared motor 2. Then, the rotation shaft 2a of the geared motor 2 starts re-rotating from the half-rotation position in a counterclockwise direction (direction of arrow M) at a predetermined rotation number (for example, 5 rpm, 6 rpm, or the like). As a result, the pulley 5 rotates together with the pin 12 in the same direction and the valve body 15 approaches the valve seat 14, so that the drain valve 13 starts closing and the circular cam 3 starts rotating in the same direction at the same time. The pieces 6, 7 remain closed.
[0021]
When the rotating shaft 2a of the geared motor 2 rotates 360 ° and returns to the initial position, the pin 12 reaches the top dead center as shown in FIG. 3C, and the drain valve 13 is closed. At the same time, the lower contact piece 7 that has been in contact with the upper contact piece 6 separates from the upper contact piece 6 due to its elastic force, and as shown in FIG. Then, the rotation completion signal S4 is input from the detection circuit 9 to the control circuit 10. In response to this, the control circuit 10 outputs a motor stop signal S2 to the motor drive circuit 8, and the motor drive circuit 8 cuts off the power supply to the geared motor 2. Then, since the rotation shaft 2a of the geared motor 2 stops its rotation, the drain valve 13 is maintained in the closed state, and it is possible to newly supply water to the water reservoir 11 to perform the washing operation and the rinsing operation. Become.
[0022]
Also at this time, while the rotating shaft 2a of the geared motor 2 is rotating 180 ° from the half-rotation position to the initial position, the user may inadvertently switch the operation, and the drain valve 13 may open and close abnormally. Therefore, in order to cope with this, the control circuit 10 counts the elapsed time from the output of the motor rotation signal S1 by the timer 10a, and adds a slight adjustment time α to the normal half rotation time t of the geared motor 2. It is monitored whether or not the rotation completion signal S4 is input before the predetermined time T (= t + α) elapses.
[0023]
If the rotation completion signal S4 is input before the predetermined time T elapses after the output of the motor rotation signal S1, the control circuit 10 causes the circular cam 3 to rotate normally and the drain valve 13 to operate normally. Judge that it is working. Conversely, if the rotation completion signal S4 is not input after a predetermined time T has elapsed since the output of the motor rotation signal S1, the control circuit 10 stops the rotation of the circular cam 3 halfway due to some abnormality and the drain valve 13 is determined to be in an incompletely opened / closed state, and a motor initialization signal S3 is output to the motor drive circuit 8. In response to this, the motor drive circuit 8 initializes (initializes) the geared motor 2 and returns the rotary shaft 2a to the initial position. Accordingly, even if the drain valve 13 has an open / close abnormality, the subsequent operation can be performed normally, and the reliability of the drain valve 13 is improved.
[0024]
If the user accidentally turns off the power while the washing machine is in use or the power is turned off due to a power failure, the control circuit 10 outputs a motor initialization signal S3 to the motor drive circuit 8 immediately after the start of energization. In response to this, the motor drive circuit 8 initializes the geared motor 2 and returns its rotary shaft 2a to the initial position. Then, the opening / closing operation of the drain valve 13 from the closed state is always guaranteed, so that it is possible to reliably deal with the opening / closing abnormality of the drain valve 13 and improve the reliability.
[0025]
In the above embodiment, the case where the geared motor 2 is used has been described. However, a motor other than the geared motor 2 (for example, a stepping motor) can be used instead.
[0026]
【The invention's effect】
As described above, according to the first aspect of the present invention, even if the user inadvertently switches the operation during use of the washing machine and the drain valve opens and closes abnormally, the subsequent operation is performed. The drain valve always opens and closes from the closed state even if the user accidentally turns off the power while the washing machine is in use or the power is cut off due to a power failure. Therefore, it is possible to provide a drainage control device for a washing machine capable of reliably addressing the opening / closing abnormality of the drainage valve and improving the reliability.
[0027]
According to the second aspect of the present invention, only a pair of contact pieces is sufficient to detect the fully opened state and the closed state of the drain valve, and therefore, a conventional leaf that requires not only two leaves but also a neutral leaf is required. Since the number of parts can be reduced as compared with the conventional drainage control device, productivity and yield can be increased, costs can be reduced, and the frequency of failures can be reduced.
[Brief description of the drawings]
FIG. 1 is a view showing an embodiment of a drainage control device for a washing machine according to the present invention, wherein (a) is a front view, (b) is a right side view, and (c) is a bottom view. is there.
FIG. 2 is a chart showing an input state of an OFF signal and an ON signal.
3A and 3B are diagrams showing the movement of a circular cam, wherein FIG. 3A is a state diagram of an initial position, FIG. 3B is a state diagram of a half rotation (180 °), and FIG. FIG.
[Explanation of symbols]
1 ... Drainage control device for washing machine 2 ... Geared motor (motor)
2a Rotating shaft 3 Circular cam 3a Convex portions 6, 7 Contact piece 8 Motor drive circuit 9 Detection circuit 10 Control circuit 13 Drain valve S1 Motor rotation signal S2 …… Motor stop signal S3 …… Motor initialization signal S4 …… Rotation completion signal T …… Predetermined time

Claims (2)

In a drainage control device (1) for a washing machine that opens and closes a drainage valve (13) according to a rotation angle of a rotation shaft (2a) of a motor (2),
A control circuit (10) for outputting a motor rotation signal (S1);
A motor drive circuit (8) for receiving a motor rotation signal from the control circuit and rotating the rotation axis of the motor;
A detection circuit (9) that detects a fully open state and a closed state of the drain valve based on a rotation angle of a rotation shaft of the motor and outputs a rotation completion signal (S4) to the control circuit;
A function of receiving a rotation completion signal from the detection circuit and outputting a motor stop signal (S2) to the motor drive circuit is added to the control circuit,
A function of stopping the rotation axis of the motor in response to the motor stop signal from the control circuit is added to the motor drive circuit,
A function of outputting a motor initialization signal (S3) to the motor drive circuit when a rotation completion signal is not input even after a predetermined time (T) has elapsed since the output of the motor rotation signal is added to the control circuit. ,
A drain control device for a washing machine, wherein a function of initializing the motor in response to a motor initialization signal from the control circuit and returning a rotation axis thereof to an initial position is added to the motor drive circuit. A circular cam (3) having a protruding portion (3a) formed on the periphery is mounted on a rotating shaft (2a) of the motor (2),
A pair of contact pieces (6, 7) are supported so as to be able to freely contact and separate from each other, and one of the contact pieces (7) is brought into contact with the peripheral portion of the circular cam;
2. The washing machine according to claim 1, wherein a full open state and a closed state of the drain valve (13) are detected based on the contact and separation of the pair of contact pieces accompanying the rotation of the circular cam. 3. Drainage control device.

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