JPS6141598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water level detection device for a washing machine with a washing and spin-drying tank that has a washing and spin-drying tank, and is capable of detecting water level in a washing and spin-driving machine that does not have a small hole for spin-drying without using a pressure switch or an air trap device. The purpose is to perform accurate water level detection.

Generally, in a fully automatic washing machine, an outer tank is provided outside the washing and dehydration tank with small holes for dewatering on the side, and water is stored inside the outer tank during washing and rinsing, and the water level can be detected by This was done by operating a pressure switch using air pressure from an air trap installed on the lower side wall of the outer tank. However, this structure has the disadvantage that it requires a large amount of washing water because it is necessary to store water between the outer tub and the washing/drying tub.

In addition, a structure has been proposed in which a washing/dehydration tank is provided without a small hole for dehydration, and water is stored only in this tank for washing.However, when detecting the water level using a pressure switch, However, since it is necessary to provide an air trap on the rotating shaft, the water channel is complicated, and the use of a drain valve and pressure switch is expensive.

The present invention has been made in view of the above problems, and one embodiment thereof will be described below.

In FIG. 1, 1 is an outer frame, 2 is a washing/dehydration tank with a non-porous peripheral wall except for at least the vicinity of the upper end;
3 is an outer tank that encloses the washing and dehydration tank 2, 4 is a pulsator placed at the center of the bottom of the washing and dehydration tank 2, 5 is a brake/clutch mechanism, 6 is a motor for washing and dehydration, 7 is a motor pulley, 8 9 is a belt, 9 is an impeller pulley, and 10 is a support rod of a vibration-proof support device hanging from the four corners of the outer frame 1.

Figures 2 and 3 show the above-mentioned vibration isolating support device, Figure 2 shows a state in which water is not being supplied to the washing and dehydrating tank 2, and Figure 3 shows a state in which water supply is completed and the amount of water is constant. Indicates a state in which this is ensured. In both figures,
Reference numeral 10 indicates a support rod as described above, and reference numeral 11 indicates a vibration-proof case made of a resin material having a spherical portion 11a at one end, in which the spherical seat 3a fixed to the outer tank 3 and the spherical portion 11a can freely slide. It is set up like this. 13 is a spring receiver made of an elastic material such as rubber, supported by the lower end surface of the support rod 10;
A compression spring 12 is inserted between the vibration isolation case 11 and this spring receiver 13. 1
Reference numeral 4 denotes a band-shaped annular electrode 15 made of a thin plate of aluminum or the like provided on the outer periphery of the lower end of the vibration-proof case 11, and a cylindrical electrode provided on the lower end of the support rod 10.
That is, the electrode 15 is arranged on the fixed side, which mainly includes the support rod 10, and the electrode 14 is arranged on the movable side, which includes the vibration-proof case 11 and the outer tank 3.

FIG. 4 is a block diagram showing the basic configuration of the control circuit, in which 16 is an AC power source, 17 is a DC power source, 18 is a detection section consisting of the electrodes shown in FIGS. 2 and 3, and 19 is a block diagram. Any oscillation frequency, e.g.
The oscillation circuit section obtains 1MHz, 20 is a water level setting section that sets the water level, 21 is a load control section that opens and closes the relay 22, and the contact 22a of the relay 22 controls the water supply valve, the motor 6 for washing and dewatering, and the timer. Controls the load of motors, etc.

Next, the operation will be explained. When the current is turned on, the water supply valve operates in the water supply process, and water is supplied into the washing and dehydration tank 2. At this time, the water level detection device is also energized. The electrodes 14 and 15 provided on the vibration isolator constitute a kind of capacitor, and since the weight of the outer tank is light at the initial stage of water supply, the compression spring 12 is in an extended state as shown in Fig. 2. and the gap between the electrodes 14 and 15 is large;
The capacitance value between the electrodes 14 and 15 shows a small value.

Therefore, in this state, the oscillation circuit section 19 oscillates at the set oscillation frequency, and the load control section 21
is not operating, so relay 22 is not operating,
Relay contact 22a is closed to the NC side.

As the water supply continues and approaches the set water level, the compression spring 12 is compressed and the electrode 1
Since the distance between the electrodes 4 and 15 becomes close, both electrodes 14,
15 increases. When water is supplied to the set water level, the oscillation circuit section 19 is unable to maintain the set frequency due to the increase in capacitance between the electrodes 14 and 15, and oscillation stops or the oscillation voltage decreases. Since the value falls below the reference value, the load control unit 21 operates, and the relay 22 operates to close contact 2.
2a is switched to the NO side, the motor 6 is operated, the pulsator 4 is rotated, and washing or
Rinsing will begin. Dewatering is performed by operating the brake/clutch mechanism 5 so that the motor 6 rotates the washing/dehydrating tub 2.

Note that the anti-vibration support devices are generally arranged at the four corners of the outer frame 1, but if electrodes are arranged on at least two opposing support devices, even if the outer frame 1 is poorly installed and cannot be placed in a horizontal position, errors can be avoided. It is possible to detect weight changes and obtain a constant water level.

As described above, according to the present invention, changes in the weight of the outer tank are detected as changes in the capacitance between the electrodes by the electrodes provided on the vibration isolating support device that supports the outer tank, and this change is further reflected in the oscillation circuit section. Since the system captures the water level in the oscillation state, the water level detection means can detect the water level in the washing/spinner tank without coming into contact with the water, eliminating the need for the complicated and expensive configuration required in the past, and is also useful for saving water. It is possible to provide various configurations.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a washing machine showing an embodiment of the present invention, FIGS. 2 and 3 are cross-sectional views of its anti-vibration support device, and FIG. 4 is a block diagram showing the basic configuration of its water level detection circuit. It is a diagram. 1...Outer frame, 2...Washing/dehydration tank, 3...Outer tank, 4...Pulsator, 10...Support rod, 12...
...Compression spring, 14, 15... Electrode, 19...
...Oscillation circuit section.

Claims (1)

[Scope of Claims] 1. A washing/dehydration tank having a pulsator at the bottom is rotatably arranged in an outer tank, and a peripheral wall of the washing/dehydration tank except for at least the vicinity of the upper end is a non-porous wall, and is vibration-proofly supported by an outer frame via a support rod and a spring, electrodes are arranged on the fixed side including the support rod and the movable side including the outer tank, and the oscillation is activated by detecting the capacitance difference between the electrodes. 1. A water level detection device for a washing machine with a dehydrating function, characterized in that a control circuit including a circuit section is provided, and a load is controlled by the control circuit. 2. A dehydrating and washing machine according to claim 1, characterized in that at least two vibration-proof support devices are provided with a pair of electrodes whose relative positions change as the weight of the movable side including the outer layer changes. Machine water level detection device.