JPS63181794A - Washing machine water level detection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a water level detection device for a washing machine used in a general household, which automatically performs a series of processes such as washing, draining, rinsing, and spin-drying.

Conventional technology Conventionally, a water level detection device for a washing machine that automatically performs a series of processes such as washing, draining, rinsing, and dehydrating has a 7° air trap 2 installed at the bottom of the side wall of the outer tub that houses the washing and dehydrating tub. The water level was detected by moving a diaphragm by the air pressure inside the air trap, which varied according to the water level in the washing/drying tank, and by the stress caused by the pressure, the movable contacts were operated. Furthermore, the operating position of this movable contact could be mechanically set to three levels: high, medium, and low. In addition, JP-A-55
As shown in Japanese Patent No. 76699, there is also a system that detects the water level by replacing the movable position of the diaphragm with a change in inductance. That is, the water level can be detected by attaching a magnetic body to the diaphragm and detecting the inductance that changes as the position of the magnetic body moves. Specifically, in order to detect inductance, an oscillation circuit was connected to a coil to detect changes in inductance.

Problems to be Solved by the Invention However, with devices that move movable contacts mechanically, it is mechanically difficult to adjust the water level steplessly, and it is not possible to perform detailed water level control according to the amount of laundry. It had some problems.

For those that detect inductance changes, go to step 3. Although it is possible to perform stepless water level control, an oscillation circuit is required in addition to the coil, and this inductance is input to the microcomputer that controls the washing machine's operation. However, there were problems in that the interface would be complicated and the water level detection device would be expensive.

In view of the above problems, it is an object of the present invention to provide a water level detection device for a washing machine that does not require a complicated interface and can detect the water level steplessly.

Means for Solving the Problems In order to achieve the above object, the water level detection device for a washing machine of the present invention has a water level detection device at the bottom of the outer washing tank that detects the water level in the washing and dewatering tank depending on the water level in the washing machine. An air trap is provided in which air is compressed, and the air pressure moves a diaphragm equipped with a magnet. Changes in the magnetic flux of the magnet are converted into voltage by a Hall element, and the water level is determined based on this voltage value.

Effect With the above configuration, a change in the air pressure within the air trap results in a change in the distance between the Hall element and the magnet, and therefore a change in the magnetic flux applied to the Hall element, so that the output voltage of the Hall element is output linearly. The output voltage of this Hall element is measured by a microcomputer with a built-in analog/digital converter, and if the water supply operation is controlled to stop when the required voltage, that is, the required water level, is reached, the water level can be controlled. can be set steplessly.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the accompanying drawings. As shown in FIG. 3, the overall structure of the washing machine in this embodiment is such that an outer tub 2 is attached to an outer box 1 with a hanging rod (not shown). The outer tank 2 houses a washing/dehydration tank 3, and a large number of holes are formed in the peripheral wall thereof.

A pulsator 4 is rotatably installed at the inner bottom of the washing and dehydrating tank 3. The drive motor 6 sends rotational force to the bearing case 6 by belt transmission, and the bearing case 6 further rotates the pulsator 4 and the washing/dehydration tank 3.

The bearing case 6 incorporates a brake device that applies a brake to the washing/dehydration tank 3 and a clutch device that controls the transmission of rotational force. A drainage lower is installed at the bottom of the outer tank 2,
Drainage of the remaining water in the outer tank 2 is controlled by a drainage electromagnetic valve 8.

Further, an air trap 9 is provided at the lower part of the side wall of the outer tank 2, and the air pressure within the air trap 9 is transmitted to a water level detection device 11 via a pressure hose 10. A water supply valve 12 that supplies water into the outer tub 2 controls the amount of washing water.

The configuration of the water level detection device 11 will be explained with reference to FIG.

A diaphragm 13 that receives air pressure from the air trap 9 via a pressure hose 1o has a magnet 14 installed in its center. This diaphragm 13 moves up and down in response to air pressure, and the upward movement of the diaphragm 13 is adjusted by a spring 16. A Hall element 16 is provided at a position facing the magnet, and this Hall element 16 outputs a voltage proportional to the distance from the magnet 14.

Next, the washing machine control device in this embodiment will be explained with reference to FIG. In other words, control the washing machine to line 6.

A microcomputer 18 constituting a control means controls the drive motor 6, drain electromagnetic valve 8, and water supply valve 12 according to information from the operation setting switch 17 and the water level detection device 11 to control the water level detection operation and the overall operation of the washing machine. do. 19-23
is an interface with the microcomputer 18.

Next, the water level detection operation will be explained. After the power is turned on, the operation setting switch 17 is operated to input water level information necessary for washing. The microcomputer 18 operates the water supply valve 12 to start water supply. Air trap 9 depending on water supply amount
The air inside is pressurized, the diaphragm 13 and magnet 14 of the water level detection device 11 move, and the Hall element 16 and magnet 14 move.
Distance with starts proximity. From this point on, the microcomputer 18 converts the output voltage of the Hall element 16 from analog to digital through the interface 19, then compares it with the water level information input through the operation setting switch 17, and when it reaches the input water level information, starts water supply. By stopping the operation of the valve 12, the water supply operation is completed and the water level detection device is activated 7.

Effects of the Invention As is clear from the above embodiments, the water level detection device for a washing machine of the present invention is equipped with a Hall element that directly converts the magnetic flux change of the magnet correlated with the water level into a voltage, so that the water level can be set steplessly. This makes it possible to precisely set the water level according to the amount of laundry to be washed, thereby preventing wasteful use of water and also making it possible to detect a state of water loss during washing operations. Furthermore, compared to current contact-type water level detection devices, since no contact parts are used, there is less deterioration due to rust, etc., and it can be used stably for a long period of time. Furthermore, compared to current water level detection devices that use coil components to detect changes in inductance, the interface with the microcomputer is
Only the D converter is required, which simplifies the configuration and provides an inexpensive water level detection device for washing machines.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a water level detection device for a washing machine according to an embodiment of the present invention, FIG. 2 is a block diagram of the control device, and FIG. 3 is a sectional view of the washing machine. 9...Air trap, 11...Water level detection device, 13...Diaphragm, 14...
...Magnet, 16. Old...Hall element, 18...
・Microcomputer, 19-23...Interface. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure q--Ichigo? J U,,7゜

Claims (1)

[Claims] An air trap is installed in which the air inside is compressed according to the water level in the washing and dehydrating tank.The air pressure inside this air trap moves a diaphragm equipped with a magnet, and changes in the magnetic flux of the magnet are detected using a Hall element. A water level detection device for a washing machine that converts a voltage and determines the water level in the washing and dehydrating tub based on the voltage value of the Hall element.