JP2873118B2 - Drum type washing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control mechanism for stopping a drum at a fixed position in a drum type washing machine having a DC motor.

[0002]

2. Description of the Related Art Conventionally, there is hardly any washing machine that can perform washing and drying all at once with the same drum, and there are some overseas products. However, a DC motor is used for driving the washing machine and an electronic circuit that uses a microcomputer to control the rotation speed. There is nothing to control.

[0003]

Here, in a drum type washing machine in which washing and drying are integrated by rotation about a horizontal axis, it is necessary to stop a drum opening / closing opening on the upper surface of the washing machine in order to take out washing and dried products. There is.

For this purpose, since the DC motor and the drum are connected by a speed reducer such as a pulley, the position of the rotor of the motor and the position of the drum opening / closing port are irrelevant. The position must be detected, the drive signal must be turned off, and the drum opening / closing opening must be stopped at a fixed position on the top of the washing machine.

[0005] However, the rotational torque varies depending on the cloth load of the washed / dried material, and when the normal drive signal is turned off to stop, the inertia force varies depending on the number of revolutions and the load before the stop, and the drum is stopped at a fixed position. There was no suitable method.

In view of the above, it is an object of the present invention to provide a drum type washing machine capable of stopping a drum at a predetermined position by controlling a DC motor by an inverter.

[0007]

As shown in FIG. 1, a DC brush for driving a rotary drum 2 is provided.
A motor 3, a power converting circuit 16 for varying the applied voltage of the DC brushless motor 3 for controlling rotation of the DC brushless motor 3, controls the Deyutei of Chiyotsupa via the drive circuit 15 to the power conversion circuit 16 In a drum type washing machine including a control circuit 13 for outputting a signal and a drum position detector 9 for detecting a position of the drum 2, the drum type washing machine can collectively perform washing and drying.
, A low-speed driving means 30 for gradually lowering the duty of the chopper when receiving a fixed position stop command, and a duty fixing means 31 for fixing the duty of the chopper at a predetermined drum rotation speed. rotation period measurement means (3) for measuring the rotation period of the drum 2 in this case
2, a duty reduction ratio determining means 33 for determining the duty reduction ratio of the chopper based on the duty value fixed by the duty fixing means 31 and the measurement value from the rotation period measuring means 32; When the drum position signal is input from the position detector 9, the duty of the chopper is applied, and the drive circuit 1
5 is provided with a drum braking means 34 for applying a braking operation to the drum 2 by fixing the drive signal from 5 for a fixed time.

[0008]

In the above-mentioned means for solving the above problems, when a fixed position stop command of the rotary drum 2 is received, the duty of the chopper is gradually lowered by the low speed operation means 30 to reduce the motor rotation speed, and when the drum rotation speed becomes sufficiently low. The duty fixing means 31 fixes the duty of the chopper,
The rotation period measuring means 32 measures the time of one rotation of the drum 2.

Then, the fixed duty and the drum 1 are fixed so that the fixed position stop is performed in the next one rotation.
The duty reduction ratio determining means 33 determines the duty reduction ratio of the duty of the chopper from the function of the rotation time.

When the duty of the chopper becomes zero immediately before the target stop position and the motor is rotated to the target stop position by the inertial force, the drum brake means 34 applies a chopper having a certain duty ratio to fix the drive signal for a certain time. ,
The drum 2 is stopped at a fixed position by applying a kind of brake operation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, control of a drum type washing machine and a DC brushless motor according to the present invention will be described with reference to the drawings. FIG.
FIG. 2 is a functional block diagram of a control circuit for stopping a drum of a drum type washing machine according to an embodiment of the present invention, FIG. 2 is a block diagram of a control circuit of a DC brushless motor used in the drum type washing machine, and FIG. FIG. 4 is a timing chart of a P-Tr 6-phase output, a PWM output, and a base drive signal from the microcomputer.

The present invention is particularly effective for a motor having a large torque fluctuation around the horizontal axis.
As shown in FIG. 3, a rotating drum 2 for putting laundry in a washing machine main body 1 is rotatably provided, and the drum 2 and a DC brushless motor 3 are connected by a belt 5 by pulleys 4a and 4b for reduction.

The rotary drum 2 has a shaft 6,
The drum position of the rotary drum 2 attached to the drum outer tank 8 via the bearing 7 is detected by a position detection sensor 9b of a magnet 9a attached to the pulley 4a.
And the position detection sensor 9b constitute a drum position detector 9.

A drum opening / closing opening 2a for taking in / out the laundry is formed on the outer peripheral surface of the rotating drum 2, and is opened / closed by a lid. An opening is formed on the upper surface of the outer tub 8, and is opened and closed by an opening / closing lid 8a.

The drum position detector 9 outputs a drum position signal when the drum opening / closing opening 2a comes to a position facing the opening / closing lid 8a of the outer tub 8.

Here, the DC motor 3 is used mainly to make it easy to obtain a large torque at the time of starting. The reason for using the brushless motor is to prevent the durability of the motor from being reduced due to the contact wear between the commutator and the brush.

Next, the control section of the DC motor 3 will be described with reference to FIG. In this DC motor control unit, the AC power supply 11 is smoothed to DC by the rectifying and smoothing circuit 12, and the P-Tr 6-phase output 14 of the microcomputer 13 is used as a control circuit via the drive circuit 15 as power for the power conversion circuit 16. A DC voltage is applied to the motor 3 by switching the transistor circuit (P-Tr).

To vary the applied voltage, a P-Tr6
Upper arm of phase output 14 and PWM output 17 of microcomputer 13
Is ORed by an OR circuit 18 to control the base drive output of the P-Tr 16 to vary the duty of the chopper.

For controlling the rotation speed of the motor 3, the rotation speed of the DC motor 3 is pulse-input to the rotation speed input terminal of the microcomputer 13 by the rotation speed sensor 19 using a photo interrupter or the like.

Position sensor 20 using Hall element or the like
a, 20b, and 20c, the rotor position of the DC motor 3 is input to the rotor position detection means 21a of the microcomputer 13 via the position detection circuit 21, and an output corresponding to the input signal pattern is output from the P-Tr 6-phase output terminal 14. The motor is energized, the motor is excited, and the duty of the chopper is varied to vary the voltage applied to the motor to control the rotation speed.

FIG. 4 shows a P-Tr 6-phase output 14 and a PW output from the microcomputer 13 when the rotation speed control is performed.
5 shows a timing chart of an M output 17 and a base drive signal after passing through a drive circuit 15.

In the drum type washing machine for controlling the DC motor 3, the rotation speed detecting means 22 for detecting the rotation speed of the DC motor 3, the duty control means 23 for controlling the duty of the chopper, and the motor Revolution N
And a target rotation speed N1; and a feedback control means 25 for performing feedback control of the duty of the chopper based on the comparison result by the comparison means 24.

The rotation speed detecting means 22 is a concept including a rotation speed sensor 19 and a CPU in the microcomputer 13 which receives and calculates this signal. The duty control means 23, the comparison means 24, and the feedback control means 25 include a data RAM, a program ROM, a CP
U and the like.

With this configuration, the DC motor 3 is started, and the PWM output 17 of the microcomputer 13 and the P-Tr 6
The OR of the phase outputs 14 is calculated, the duty of the chopper is increased at a constant speed and at a constant rate, and the rotation speed of the motor 3 is controlled after a lapse of a predetermined time.

This is because, in general, in the case of a DC brushless motor, the duty of the chopper and the motor torque, and the motor torque and the rotation speed are in a proportional relationship. However, in this system in which the drum rotates vertically, the load fluctuation is too large. This is because there is no inertial force particularly at the time of starting, and in such a case, even if the feedback control is performed, stable rotation speed control cannot be realized.

Therefore, the duty of the hopper is raised to a certain value from the time of starting, and thereafter, the duty of the hopper is fixed to a certain value by the duty control means 23 until the rotational speed becomes relatively stable. The motor speed N by the means 24 is compared with the target speed N1, and the feedback control means 25 performs feedback control on the duty of the chopper, thereby enabling stable speed control.

Now, the drum position signal and the drum opening / closing opening 2a
Is synchronized with being located on the top of the washing machine,
After the motor control microcomputer 13 receives the home position stop command,
Even if the drive signal is turned off simultaneously with the input of the drum position signal from the drum position detector 9, the rotating drum 2 does not stop at the target stop position on the upper surface of the washing machine due to the inertial force but goes too far.

In order to stop the drum 2 at a fixed position when a fixed position stop command is received, the control circuit 13 of the drum type washing machine of the present embodiment includes the drum 2 as shown in FIG.
, A low-speed driving means 30 for gradually lowering the duty of the chopper when receiving a fixed position stop command, and a duty fixing means 31 for fixing the duty of the chopper at a predetermined drum rotation speed. rotation period measurement means (3) for measuring the rotation period of the drum 2 in this case
2, a duty reduction ratio determining means 33 for determining a duty reduction ratio of the chopper based on the duty value fixed by the duty fixing means 31 and a measurement value from the rotation period measuring means 32, and a duty reduction ratio determining means 33 When the drum position signal from the drum position detector 9 is input, the duty of the chopper is applied, and the drive signal from the drive circuit 15 is supplied for a certain period of time. Drum braking means 34 for fixedly applying a braking action to drum 2
And drive stopping means 35 for confirming that the drum 2 has stopped at a fixed position and turning off the drive signal.

In the duty reduction ratio determining means 34,
The reduction ratio as shown in FIG. 6 is determined based on a function of the fixed value D of the duty and the time T required for the drum 2 to make one rotation.

In the above configuration, when the microcomputer 13 receives the fixed position stop command, the duty of the chopper is gradually lowered by the low-speed operation means 30 and the motor rotation speed becomes sufficiently low (for example, when the drum rotation speed is 20 rpm or less). And the first drum position signal is input), the duty fixing means 31 fixes the duty of the chopper as shown in FIG. And the rotation period measuring means 3
2, the time Tsec during which the drum 2 makes one rotation is measured.

Then, the duty reduction ratio determining means 33 calculates the duty reduction ratio of the chopper from the function of the duty fixed value D and the time T of one rotation of the drum 2 by the duty reduction ratio determining means 33 so that the fixed position stop is performed in the next one rotation. Decide. The value of the reduction ratio obtained from the function is as shown in FIG.

Generally, when the load is large, the rotation of the drum due to the inertial force is small, so that the reduction ratio becomes large,
Conversely, when the load is small, the rotation of the drum due to rotation is large, so the reduction ratio becomes large.

By reducing the duty of the chopper at the reduction ratio determined in this way, the drum opening / closing opening 2a is rotated to the position just before the target stop position on the upper surface of the washing machine while gradually reducing the number of rotations of the drum. After that, the drum 2 is rotated by the inertial force to reach the target stop position.

When the drum position signal is input from the drum position detector 9 when the motor rotates to the target stop position, a certain fixed duty (for example, the fixed value D) is applied by the drum braking means 34 by the drum braking means 34. The drive signal is fixed for a certain time (for example, 300 ms) so as not to generate a rotating magnetic field. In this way, a kind of brake operation is applied to stop the drum 2.

Then, the driving stop means 35 causes the drum 2
Is completely stopped, and turn off the drive signal.
Then, the drive opening / closing opening 2a stops at a fixed position on the upper surface of the washing machine.

As described above, by fixing the drive signal for a certain period of time when the duty of the chopper is sufficiently lowered, the drive opening / closing port is stopped at a fixed position on the upper surface of the washing machine without a large current flowing through the motor drive power transistor. It becomes possible.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention.

For example, in the above embodiment, the rotational speed detecting means 2
2, the number of rotations is detected by a signal from the number of rotations sensor 19, but instead of this, the number of rotations is detected from the input signal by using three position sensors 20a, 20b, 20c for detecting the rotor position. It may be configured as follows.

Further, the control of the DC motor according to the present invention is not limited to the brushless type, but can be applied to the control of a DC motor using a brush. Further, the power conversion circuit 16 may be a power conversion element other than the power transistor.

[0040]

As is apparent from the above description, according to the present invention, when the rotation speed of the drum type washing machine is controlled by the DC brushless motor to stop the rotating drum, the duty of the tipper is gradually lowered to reduce the drum. Since the braking is applied after the rotation speed is reduced, the drum can be stopped at the moment when the drum position signal is output.

Therefore, 1) The drum opening / closing opening can be stopped at a fixed position on the upper surface of the washing machine.

2) When stopping at a fixed position, when the brake is applied, the rotation speed of the drum is sufficiently reduced, so that it is performed.
Excessive current does not flow through the power transistor of the power conversion circuit.

There are excellent effects as described above.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a control circuit for stopping a drum of a drum type washing machine according to an embodiment of the present invention.

FIG. 2 is a block diagram of a rotation speed control circuit of the DC brushless motor.

FIG. 3 is a mechanism diagram of a drum type washing machine.

FIG. 4 shows a P-Tr 6-phase output from a microcomputer and PW
FIG. 4 is a timing chart of an M output and a base drive signal.

FIG. 5 is a timing chart showing a drum position signal, a drum rotation speed, and a duty ratio of a nipple after the rotation speed of the drum becomes 20 rpm or less.

FIG. 6 is a diagram illustrating a duty reduction ratio of the chopping hopper determined from the duty of the chopping hopper and the time of one rotation of the drum.

[Explanation of symbols]

Reference Signs List 2 rotating drum 3 DC motor 9 drum position detector 13 control circuit 15 drive circuit 16 power conversion circuit 30 low-speed operation means 31 duty fixing means 32 rotation cycle measuring means 33 duty reduction ratio determining means 34 drum braking means

Claims (1)

(57) [Claims] 1. A direct current brushless motor <br/> over motor for driving the rotary drum, DC bra for controlling the rotation of the DC brushless motor
A power conversion circuit that changes the voltage applied to the Siles motor, and a control circuit for outputting a signal for controlling the Deyutei of Chiyotsupa through the drive circuit to the power conversion circuit, and a drum position detector for detecting a position of the drum A drum-type washing machine capable of batching from washing to drying, comprising: a low-speed operation means for gradually lowering the duty of the chopper to reduce the rotation speed of the motor when receiving a fixed position stop command of the drum; becomes the drum rotation speed and Deyutei fixing means for fixing the Deyutei of Chiyotsupa, the rotation period measurement means for measuring the rotation period of the drum in this case, Deyutei value which is fixed by the Deyutei fixing means and from said rotation period measurement means A duty reduction ratio determining means for determining a duty reduction ratio of the chopper based on the measured value; Drum brake means for applying the duty of the chopper when the drum position signal is input from the drum position detector and fixing the drive signal from the drive circuit for a fixed time to perform a brake operation on the drum And a drum-type washing machine.