JPH08886A - Automatic washing machine - Google Patents

Abstract

PURPOSE:To improve accuracy for detecting the weight of laundry by detecting the inertial rotation amount of a motor by receiving light from a light emitting element through a slit for detection, which is formed on a rotary panel to be rotated while being interlocked with the motor, at a light receiving element. CONSTITUTION:When a motor 3 is operated in a short time and stopped later in the state of putting laundry in a washing vessel 1, the light from a light emitting element 12 is passed through the translucent slit on a rotary panel 11 and received by a light receiving element 13, and the number of times of light reception is proportional to the elastic rotation amount of the rotary panel 11. This light received signal is turned to a digital signal by a waveform shaping circuit 14 and read into a microcomputer 15. Therefore, since a lot of translucent slits are slenderly formed on the rotary panel 11, even when the rotation amount of the rotary panel 11 is small, the rotation amount can be accurately detected. Thus, the weight of laundry can be accurately detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laundry weight detecting structure for an automatic washing machine.

[0002]

2. Description of the Related Art Some automatic washing machines detect the weight of laundry and perform a washing operation in a washing time corresponding to the weight.

The weight of the laundry is detected by detecting the amount of inertial rotation of the motor after the motor has been running for a short period of time in a state where the laundry is put in the washing tub, and the amount of inertial rotation is detected. Is less. As shown in FIG. 3, conventionally, the amount of inertial rotation is detected by detecting a counter cycle of the counter electromotive voltage waveform generated by the inertial rotation of the motor 20 by the photocoupler 21, and shaping the detected signal. The circuit 22 shapes the digital waveform so that the microcomputer 23 can read it.

[0004]

However, in the case of the above-described method of detecting the inertial rotation amount, the number of pulses generated during one rotation of the motor is constant due to the mechanism of generating the counter electromotive voltage. Since the number of pulses in the interval cannot be increased, there is a limit to increase the detection accuracy.

The present invention has been made in view of the above circumstances, and an object thereof is to improve the accuracy of detecting the weight of laundry.

[0006]

SUMMARY OF THE INVENTION According to the present invention, an automatic washing machine detects the weight of a laundry by stopping the motor for a short period of time in a state where the laundry is put in the washing tub and detecting the inertial rotation amount thereof. In the machine, a detection plate is provided with a rotating plate that rotates in conjunction with the motor, and a pair of light emitting element and light receiving element that are arranged relative to the rotating plate, and from the light emitting element that passes through the detection slit of the rotating plate. The light receiving element receives light to detect the inertial rotation amount of the motor.

[0007]

According to the present invention, since the inertial rotation amount of the motor is detected by receiving the light from the light emitting element which has passed through the detecting slit of the rotary plate by the light receiving element, the number of detecting slits of the rotary plate is increased. By doing so, it becomes possible to accurately detect the amount of inertial rotation of the motor.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a structure for detecting the weight of laundry in an automatic washing machine according to the present invention. 1 is a washing tub in which laundry 2 is stored, 3
Is a motor and 4 is a pulsator which is rotated by the motor 3. 6 is a belt for transmitting power from the drive shaft 7 of the motor 3 to the operating shaft 8 of the pulsator 4.

At the end of the drive shaft 7 of the motor 3,
As shown in FIG. 2, a circular rotary plate 11 on which a plurality of light-transmitting slits 10 for detection is radially formed is attached horizontally, and the light-transmitting slits 1 are provided above and below the rotary plate 11.
A pair of the light emitting element 12 and the light receiving element 13 at a position facing 0
And are arranged. Reference numeral 14 is a waveform shaping circuit, and 15 is a microcomputer.

Next, the laundry weight detection operation in the above embodiment will be described. When the motor 3 is stopped for a short time in a state where the laundry 2 is put into the washing tub 1 and then stopped, the rotary plate 11 rotates due to the inertial rotation of the motor 3, whereby the light from the light emitting element 12 is received through the light transmitting slit 10. Element 1
The number of received light is proportional to the rotation amount of the rotary plate 11. The received light signal is converted into a digital signal by the waveform shaping circuit 14 and read by the microcomputer 15.

Therefore, by forming the light-transmitting slits 10 of the rotary plate 11 to be thin and providing a large number thereof, the rotary plate 11
Even if the rotation amount is small, the rotation amount can be accurately detected, and thus the laundry weight can be accurately detected.

In the above-described embodiment, the light-emitting element and the light-receiving element are arranged on both sides of the rotating plate as the light-transmitting slit for the detection, but the light-emitting element and the light-receiving element are arranged on one side of the rotating plate as the reflecting slit. It may be arranged.

[0013]

According to the present invention, by increasing the number of detection slits in the rotary plate, the inertial rotation amount of the motor can be detected with high accuracy, and the weight of the laundry can be detected with higher accuracy. As a result, efficient washing can be performed during the operating time corresponding closely to the amount of laundry.

[Brief description of drawings]

FIG. 1 is a block diagram showing the detection of the weight of laundry in an automatic washing machine according to the present invention.

FIG. 2 is a plan view of a rotary plate portion.

FIG. 3 is a circuit diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Washing tub 2 Laundry 3 Motor 10 Translucent slit (slit for detection) 11 Rotating plate 12 Light emitting element 13 Light receiving element

Claims (1)

[Claims] 1. An automatic washing machine for detecting a weight of a laundry by stopping a motor for a short period of time in a state where a laundry is put in a washing tub and detecting the inertial rotation amount of the motor.
It is equipped with a rotating plate that has a slit for detection and rotates in conjunction with the motor, and a pair of light emitting element and light receiving element that are arranged relative to the rotating plate, and receives light from the light emitting element that has passed through the detecting slit of the rotating plate. An automatic washing machine characterized by detecting the inertial rotation amount of a motor by receiving light from an element.