JPS59166196A - Water level detector of dehydrator washer - 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 the Invention The present invention relates to a water level detection device for a washing machine with a washing and spin-drying function having a washing and spin-drying tub whose peripheral wall except at least the upper end is a non-porous wall.

Conventional structure and its problems Conventionally known dehydrating and dehydrating washing machines
An outer tank is provided on the outside of the washing and dehydration tank with small holes for dewatering on the peripheral side. During washing and rinsing, water is collected inside the outer tank, and the water level is detected on the lower side wall of the outer tank. This was done by operating a pressure switch in response to changes in air pressure in an air trap. However, this structure has the disadvantage that a large amount of washing water is required because water is stored between the outer tub and the washing/drying tub.

In addition, we have installed a washing and dehydration tank that does not have small holes for dehydration.
It is conceivable to collect water only in this tank and wash the clothes, but in this case, if the water level is detected using a conventional pressure switch, it is necessary to install an air trap on the rotating shaft. Unfortunately, waterways become complicated,
Furthermore, since a drain valve and a pressure switch are required, assembly is difficult, accuracy is difficult to achieve, and the cost is high.

Therefore, we installed a float with a magnet that moves up and down according to the water level in the washing and dehydration tank, and a reed switch that opens and closes depending on the magnet of this float, and the reed switch is placed between the washing and dehydration tank and the bearing part. A conceivable method is to connect to a control circuit via a sliding contact provided, but this poses a major problem in practical use because it is difficult to obtain durability due to wear of the sliding portion, etc., and a waterproof structure.

OBJECTS OF THE INVENTION The present invention aims to solve the above-mentioned conventional problems and provide a water level detection device that does not cause wear on the sliding parts and has a waterproof structure.

Structure of the Invention In order to achieve the above-mentioned object, the water level detection device for a washing machine with dehydration and dehydration according to the present invention includes a washing and dehydration tank whose circumferential wall except at least the upper end is a non-porous wall, and a washing and dehydration tank which is rotatably housed. An outer tank, a detection unit for detecting water level arranged at a predetermined position of the washing and dehydration tank, and a water level detection signal from this detection unit is externally connected by magnetic coupling between a primary winding and a secondary winding. The outer tank is made of a resin material, and at the center of the bottom of the outer tank, a recess with an opening inward of the outer tank is provided integrally with the outer tank. The secondary winding is fixed to the washing and dehydrating tank, the primary winding connected to the oscillation circuit is accommodated in the recess, and the wall thickness of the side wall on the gap side of the primary and secondary windings is adjusted. , and the others are also formed thinly.

Description of examples An embodiment of the present invention will be described below.

In the figure, 1 is an outer frame, 2 is a washing/dehydration tank with a non-porous peripheral wall except for at least two ends, 3 is an outer tank that houses the washing/dehydration tank 2, and 4 is an inside of the washing/dehydration tank 2. The pulsator is placed in the center of the bottom, 5 is the brake/clutch mechanism, 6 is the motor, and 7 is the motor pulley.

8 is a belt, 9 is an impeller pulley, and 10 is a vibration-proof support device hanging from the four corners of the outer frame 1, which supports the vibration system such as the outer tank 3 and the motor 6. One is a rotary transformer having a movable part, 11a is the primary winding of this rotary transformer 11, and 11b is the secondary winding of the transformer 11. The secondary winding 11b is fixed to the outer bottom of the washing and dehydrating tank 2,
The primary winding 11a is fixed to the inner bottom of the outer tank 3.

Reference numeral 12 denotes a lint filter application circulation path provided on a part of the side wall of the washing/dehydration tank 2, and a lint filter application filter 13 is provided at the upper part. 14a, 14. b.

14c is an electrode for water level detection provided in the lint filter application circulation path 12, electrode 14c is for water level reset detection, electrodes 14a and 14b are for water level set detection, and electrode 14a is for high water level, electrode 14b is for water level detection. detects low water level.

2 and 3 show the installed state of the rotary transformer 11, with the primary winding 11a being wound around the winding frame 11c and connected to the control circuit. The secondary winding 11b is connected to water level detection electrodes 14a, 14b, and 14c via lead wires. The primary winding 11a is inserted and fixed together with the winding frame 11c into an annular recess 3a provided at the center of the inner bottom of the outer tank 3, and is coated with an insulating resin material.

More specifically, an annular protrusion 3b is integrally formed on the inner bottom of the outer tank 3 made of a resin material.
The above-mentioned annular recess 3a is formed by opening at the top. In FIG. 2, the thickness t of the side wall 3b of the protrusion 3c corresponding to the inner diameter side of the recess 3a is made thinner than the thickness T of the side wall corresponding to the outer diameter side. The gap distance between the winding 11a and the secondary winding 11b is set as small as possible.

3 is opposite to FIG. 2 in that the secondary winding 11b is located inside the primary winding 11a, but in this case, the side wall corresponding to the inner diameter side of the recess 3a The thickness t is also thinner than the thickness T of the side wall corresponding to the outer diameter side.

In short, the gap distance between the primary and secondary windings 11a and 11b is set small in FIG.

The configuration shown in FIG. 3 is common.

FIG. 4 is a block diagram showing the basic configuration of the water level detection circuit. 15 is an AC power supply, 16 is a load control unit that controls the opening and closing of the relay 17, and the relay contact 17 of the relay 17 is shown in FIG.
a Nyoshi washing machine motor.

Controls loads such as water supply valves and timer motors. Reference numeral 18 indicates a water level setting section for setting the water level using the water level changeover switches 1ga and 19b; 20 indicates an oscillation circuit section which obtains an arbitrary oscillation frequency, for example 1 MHz, from the DC power supply section 21; 22a, 2
2b and 22c are electrodes 14a.

The resistance value of the resistor 22c, which is a solid resistor connected in series with 14b and 14c and is 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 high. is set low.

Next, the operation will be described. When the timer circuit of the washing machine is energized now, the water supply valve operates in the water supply process, and water is supplied into the washing and dehydrating tub 2. At this time, the water level detection circuit is also energized. At the initial stage of water supply, a chisel pole 1 for water level detection is installed.
Water is not in contact with any of 4a, 14b', and 14c, and the resistance value of each electrode is close to infinite. Therefore, in this state, the oscillation circuit section 2Q 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 N.
, closed on the C side.

When the water level setting unit 18 is set to a high water level, that is, when the water level selector switch 19a is turned on, water supply continues.
When the water level reaches the upper part of the electrode 14a, there is no short circuit between the electrodes and the inductance on the secondary winding 11b side changes. In this case, since the inductance on the primary winding 11a side changes at the same time, the oscillation circuit section 20 is unable to maintain the set oscillation frequency, and oscillation stops or the oscillation voltage drops below the reference value. As a result, the load control unit 16 operates, the relay 17 operates, and the relay contact 17a switches to the N and O sides, the motor 6 is operated, the pulsator 4 rotates, and washing or rinsing is performed. Begins.

Here, the primary and secondary windings 11a, 1 of the rotating transformer 11
The shorter the gap distance between the transformers 1b, the better the magnetic coupling state of the transformer 11 becomes, and it becomes possible to increase the change in inductance.

Therefore, it is preferable to make the side wall of the protrusion 3c of the outer tank 3 as thin as possible, but on the other hand, it is necessary to have sufficient mechanical strength in consideration of vibrations during dewatering.

According to the above configuration, the recess 3a corresponding to the secondary winding 11b
The thickness t of the side wall 3C does not correspond to the thickness T of the side wall 3b.
Since the wire is thinner than the wire, sufficient magnetic coupling is achieved and high mechanical strength is obtained.

Next, when the water surface reaches the water level reset detection electrode 14. c, the oscillation circuit section 20 oscillates again at the set oscillation frequency, the load control section 16 becomes inoperable, and the relays to 17
is opened, the relay contact 17a is closed again to the N and C sides, the operation of the motor 6 is stopped, and the rotation of the pulsator 40 is stopped.

Effects of the Invention As is clear from the above embodiments, according to the present invention, a recess for accommodating the primary winding is provided at the center of the bottom of the outer tank, and corresponds to the gap between the primary and secondary windings of the rotary transformer. The thickness of the side wall,
By making the wall thinner than other wall thicknesses, the gap distance between the primary and secondary windings of the rotating transformer can be shortened, and at the same time the strength of the bottom of the outer tank can be maintained. This makes it possible to stabilize water level detection performance and improve reliability. Further, after the primary winding is inserted into the recess, coating with an insulating resin material can be easily performed by casting, etc., and good productivity and quality stability can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a washing machine in an embodiment of the present invention;
FIGS. 2 and 3 are sectional views showing how the rotary transformer is installed, and FIG. 4 is a block diagram showing the basic configuration of a control circuit for water level detection. 2...Washing/dehydration tank, 3...Outer tank, 3a...
...Recessed portion, 11...Rotating transformer, 11a, 1
1b...Primary and secondary windings, 14a, 14b,
14C-・Electrode (sensing part). Name of agent: Patent attorney Toshio Nakao and 1 other person
] 1 Figure (2) b 3 Figure

Claims (1)

[Claims] a washing and dehydrating tank whose peripheral wall except at least the upper end is a non-porous wall; an outer tank that rotatably accommodates the washing and dehydrating tank; and a detection unit for detecting water level disposed at a predetermined position of the washing and dehydrating tank. , a rotary transformer for extracting the water level detection signal from the detection section to the outside by magnetic coupling between a primary winding and a secondary winding, and the outer tank is made of a resin material. At the same time, a recess with an opening inward of the outer tank is provided in the center of the bottom of the outer tank, and the secondary winding is fixed to the washing and dewatering tank, and an oscillating device is installed in the recess. A water level detection device for a dehydrating/washing machine that accommodates a primary winding connected to a circuit, and in which side walls on the gap side of the primary and secondary windings are formed to be thinner than the other side walls.