JPS6144039B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a washing and dehydrating tank whose circumferential wall except at least the upper end is a non-porous wall, and an outer tank in which the washing and dehydrating tank is rotatably installed. This relates to a water level detection device for a washing machine, which has a detection section for detecting water level at a predetermined position and extracts a water level detection signal from this detection section to the outside of the outer tub through inductance coupling. The primary winding side is made watertight, and the lead wire is taken out of the outer tank in a watertight manner to stabilize detection performance, and the primary winding can be easily attached to the outer tank. It is.

In conventional detection devices of this kind, the primary winding side of the rotating transformer is coated with resin or the like to make it watertight, and the lead wires are similarly placed watertight by passing them through a pipe or the like from the top of the outer tank. It was taken out of the outer tank.

In this case, not only does the insulation effect tend to be incomplete because watertightness on the primary winding side is ensured by coating, but also the assembly work is troublesome, and when taking out the lead wire, the area that comes into contact with water is Because of its length, it had to be protected with a fairly long pipe.

Figure 1 shows the configuration of a washing machine equipped with a general water level detection device, Figure 2 shows the same water level detection device, and
The figure shows the control circuit, in which 1 is an outer frame, 2 is a washing and dewatering tank with a non-porous peripheral wall except for at least the upper end, 3 is an outer tank in which this tank 2 is rotatably installed, and 4
is a pulsator placed at the center of the bottom of the washing and dewatering tank 2, 5 is a brake/clutch mechanism, 6 is a motor,
7 is a motor pulley, 8 is a belt, 9 is an impeller pulley, 10 is a vibration-proof support device hanging from the four corners of the outer frame 1, 11 is a rotating transformer having a movable part, and 11a is the primary winding of this transformer 11. line, 1
1b is an iron core made of a magnetic material such as ferrite, and 11c is a secondary winding of the transformer 11. The primary winding 11a is fixed to the bottom of the outer tub 3, and the secondary winding 11c is fixed to the washing/drying tub 2.

Reference numeral 12 denotes a lint filtration circulation path provided on a part of the side wall of the washing/dehydration tank 2, and a lint filtration filter 13 is provided at the upper part. 14a, 14
b and 14c are electrodes for water level detection provided in the lint filtration circulation path 12, 14c is for water level reset detection, and 14a and 14b are for water level set detection, and the former is for high water level and the latter is for low water level detection. It is for water level detection.

FIG. 2 shows the installed state of the rotary transformer 11, in which the primary winding 11a is wound around the iron core 11b, and its lead wire 11a' is protected by a watertight pipe 11d and passes through the outer tank 13. It is led out from the top and connected to the control circuit. Secondary winding 11
c is connected to the water level detection electrodes 14a, 14b, and 14c via lead wires (not shown).

Figure 3 is a block diagram showing the basic configuration of the control circuit, where 15 is an AC power supply and 16 is a relay 1.
7 is a load control section that controls the opening and closing of the washing machine motor, water supply valve,
Controls loads such as timer motors. 18 is a water level setting section that sets the water level using water level changeover switches 19a and 19b; 20 is an oscillation circuit section that obtains an arbitrary oscillation frequency, for example, 1 MHz from a DC power supply section 21; and 11 is a rotary transformer having a movable section. ,
11a and 11c are the primary and secondary windings of the rotary transformer 11; 22a, 22b, and 22c are the electrodes 1;
4a, 14b, and 14c, the resistance value of the resistor 22c connected to the water level reset detection electrode 14c is high, and the resistance value of the resistor 22a connected to the high water level detection electrode 14a is low. It is set.

Next, the operating state will be described. When the timer circuit of the washing machine is energized, the water supply valve operates in the water supply process, and water is supplied into the washing and dewatering tub 2.
At this time, the water level detection device is also energized. At the initial stage of water supply, water is not in contact with any of the electrodes 14a, 14b, and 14c, and the resistance value of the electrodes is close to an infinite value.

Therefore, in this state, the oscillation circuit section 20 oscillates at the set oscillation frequency, the load control section 16 is not operating, the relay 17 is not operating, and the relay contact 17a is closed to the NC side.

When the water level setting section 18 is connected to a high water level, that is, the water level changeover switch 19a, when water supply continues and the water level reaches the upper part of the electrode 14a, the oscillation circuit section 20 changes the set oscillation frequency. The load control unit 16 operates, the relay 17 operates, and the relay contact 17a switches to the NO side, causing the motor to stop. 6 is operated, the pulsator 4 rotates, and washing or rinsing is started. At this time, if the water level falls below the water level setting electrode 14a or 14b due to water level fluctuation, the oscillation circuit section 20 is configured to maintain the above-described state.

When the water level falls below the water level reset detection electrode 14c, the oscillation circuit section 20 oscillates again at the set oscillation frequency, the load control section 16 becomes inactive, the relay 17 is opened, and the relay contact 17a is again set to NC. When the motor 6 is closed to the side, the operation of the motor 6 is stopped.
The rotation of the valsator 4 stops.

In the conventional general water level detection structure described above, as mentioned above, it is insufficient in terms of ensuring the watertightness of the primary winding, and the pipe to protect the lead wire from water becomes long, so it is difficult to assemble the water level. It became very cumbersome to handle, and the end of the pipe
It was difficult to ensure liquid tightness between the winding and the next winding.

The present invention has been made to eliminate the above-mentioned conventional drawbacks, and embodiments thereof will be described below. Figure 4~
In FIG. 7, a primary winding 11a wound around an iron core 11b is embedded in a resin holder 23 by molding or the like. In addition, the primary winding 1
1a may be constructed of an air-core coil. The holding body 23 has a ring shape and has three bar-shaped projections 24a, 24 on its lower surface.
b, and at least one rod-shaped projection 2
4a has a hole 24a' through which a lead wire 11a' whose one end is connected to the primary winding 11a passes through. 25
a, 25b are three protrusions integrally formed on the inner surface of the bottom of the outer tank 3, at least one of which protrusions 25a is liquid-tightly fitted into the rod-shaped protrusion 24a,
The other protrusion 25b fits into the other rod-shaped protrusion 24b. By these fittings, the holding body 23, that is, the primary winding 11a is fixed to the outer tank 3 side.

The protrusion 25a is the rod-shaped protrusion 24a.
It has a hole 25a' for leading out the lead wire 11a' that has passed through the hole 24a' to the outside of the outer tank 3. The end of the lead wire 11a' led out of the outer tank 3 through the hole 25a' is connected to the oscillation circuit of the control circuit shown in FIG. Further, a sealing member 26 made of an elastic material such as rubber is interposed between the rod-shaped projection 24a and the projection 25a at the fitting portion thereof.

According to the above configuration, the primary winding 11a side can be arranged in the outer tank 3 with a highly accurate watertight structure,
The lead wire 11a' can also be taken out to the outside of the outer tank 3 due to its highly precise watertight structure.
The next winding 11a side can maintain a sufficiently insulated state. Furthermore, the primary winding 11a, the lead wire 11
There is no risk that a' will be damaged by foreign matter etc. discharged during washing.

In addition, rod-shaped protrusions 24a and 24b on the holding body 23 on the primary winding 11a side and protrusions 25 on the outer tank 3 side
By fitting with a and 25b, positioning can be easily performed, which is very advantageous in terms of work.

As described above, according to the present invention, insulation deterioration on the primary winding side and damage caused by foreign objects can be prevented, accurate water level detection can be performed, and the lead wire of the primary winding can be Since it can be immediately taken out of the outer tank from the attachment part, the lead part can be easily insulated. Further, when attaching the primary winding, the positioning can be easily performed by fitting the protrusion of the holder with the protrusion outside the outer tank, so that the work can be carried out with good work efficiency.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing the structure of a conventional general washing machine, Figure 2 is an enlarged cross-sectional view of the vicinity of the rotary transformer for water level detection, Figure 3 is its electrical control circuit diagram, and Figure 4 is the main part of the washing machine. The primary winding side of the water level detection structure in the embodiment of the invention is shown, A is an external perspective view, B and C are enlarged sectional views of the rod-like protrusion of the holder, and 5th
The figures show the outer tank structure on the primary winding side, A is a perspective view of the exterior, B and C are enlarged sectional views of the protrusions, Fig. 6 is a sectional view of the water level detection structure, and Fig. 7 is the same outline. FIG. 2... Washing and dehydration tank, 3... Outer tank, 11... Rotating transformer, 11a... Primary winding, 11a'... Lead wire, 11b... Iron core, 11c... Secondary winding,
14a, 14b, 14c... Electrode (sensing part), 2
3... Holding body, 24a, 24b... Rod-shaped projection, 2
4a'...Through hole, 25a, 25b...Protrusion, 25
a'...hole, 26...sealing member.

Claims (1)

[Claims] 1. A washing/dehydrating tank whose peripheral wall is non-porous except for at least the upper end, an outer tank in which the washing/dehydrating tank is rotatably installed, and a sensor for detecting water level provided at a predetermined position of the washing/dehydrating tank. and a rotary transformer for extracting the water level detection signal from the detection section to the outside of the outer tank through inductance coupling, and the rotary transformer has a secondary winding fixed to the washing and dewatering tank, and a rotary transformer connected to the oscillation circuit. The primary winding has a secondary winding, and the primary winding is watertightly covered with a resin holding body integrally having a plurality of bar-like protrusions, and at least one of the bar-like protrusions is provided with a lead of the primary winding. A through hole for passing the wire is formed, and a protrusion is formed in the outer tank to fit in the rod-shaped protrusion in a watertight manner, and at least one of the protrusions is provided with a through hole through which the lead wire passes through, and the outer tank is connected to the outer tank. 1. A water level detection device for a washing machine, characterized in that a hole is formed to lead the water to the outside, and a sealing member is interposed between the rod-shaped projections.