JPS59166195A - Water level detector of 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 Application + The invention relates to a water level detection device for a washing machine having a washing and dehydrating tub.

Conventional structure and its problems Conventionally, in a one-tank two dehydrating washing machine A, an outer tub is provided outside the groove rinsing/dehydrating tub with small holes for dehydration drilled in the peripheral side wall, and during washing and rinsing, the Since water was also collected inside the outer tank, the presence of water in the washing and dehydrating tank was detected using an air trap installed on the lower side wall of the outer tank.

This was done by operating a pressure switch based on changes in air pressure in the pump. 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, a washing/dehydration tank without a small hole for dewatering in the surrounding wall was proposed, and it was considered to store water only in this tank for washing, but in this case, if the water level was detected by a pressure switch, requires an air trap to be provided at the rotating shaft;
Because of the furnace, the waterways were complicated and the cost of the drainage system increased significantly.

In addition, a float having a magnet that moves downward according to the water level in the washing and dehydration tank and a reed switch that is opened and closed by the float are provided, and the one-node switch is connected to the washing and dehydration tank. A method of connecting to the control circuit via a sliding contact provided between the bearing part was considered, but the durability was poor due to wear of the sliding part, and the stabilization of the waterproof structure was not practical. This makes it possible to detect water level without using large channels or air trap devices, and improves the accuracy of water level detection.

Structure of the Invention In order to achieve the above object, the water level detection device for a washing machine of the present invention is provided with a detection section for water level detection at a predetermined position of a washing and dehydration tank whose circumferential wall except at least the upper end is a non-porous wall. A rotating lance is provided to extract the water level detection signal from the transformer to the outside through inductance coupling, and the primary winding of the rotating transformer, which is connected to the oscillation circuit, is connected to the outer tank that contains the washing and dehydrating tank. The secondary winding is wound around a provided iron core made of a magnetic material, and the secondary winding is provided in the washing/drying tank and electrically connected to the detection section.

Description of examples Hereinafter, one embodiment of the present invention will be explained based on the drawings.

In the figure, 1 is an outer frame, 2 is a washing and dehydrating tank with a non-porous peripheral wall except for at least the upper end, 3 is an outer tank containing the washing and dehydrating tank 2, and 4 is a center of the bottom of the washing and dehydrating tank 2. Palmeau arranged. In the evening, 5 is a brake/clutch mechanism, 6 is a motor, 7 (L'i motor gully, 8 is a belt, 9 is an impeller pulley, and a vibration-proof support device that hangs from the four corners of the 10U outer frame 1, and the outer tank 3 is I support it.

11 is a rotary transformer having a movable part, and 11a is an iron core made of a material such as ferrite, and the primary winding 11a of the transformer 11 is wound around it. The secondary winding 11C is fixed to )M T5'6 of the washing/drying tank 2, and the iron core 11b is fixed to the outer tank 3
is fixed.

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

14a, 14b, 14C are electrodes for water level detection provided in the lint filter application circulation path 12, 14C is for water level reset detection, 14a, 141) is for water level set detection, and the former 14a is for high water level detection. water level, the latter 14b is for low water level detection.

Here, to describe the mounting state of the rotary transformer 11 in more detail, the secondary winding M112L is connected to the control circuit as shown in FIG. 3, and the secondary winding 110 is connected to the water level setting electrode 1
4a, 14b, and 14C via lead wires.

Here, the width B of the iron core 11b is -order and the winding 11&,
The winding width A of 11C is made thicker than A/.

FIG. 3 is a block diagram showing the basic configuration of the detection circuit. 15 is an AC power supply, 16 is a load control unit that controls the opening and closing of a relay 17, and the relay contacts 17 & are used to control the washing machine motor, water supply valve, etc. Controls loads such as timer motors. 18
20 is a water level setting unit that sets the water level from the water level setting changeover switches 19a and 19bVC, 20 is an oscillation circuit unit that obtains an arbitrary oscillation frequency, for example, 1 MIIz, from the DC power supply unit 21, and 11 is the movable unit as described above. It is a rotating transformer, and 11a and 1'IC are primary and secondary windings of the transformer, and 22a, 22b, and 22c are electrodes 14a.

14b and 14C are fixed resistors connected in series, and the resistance value of the resistor 22C connected to the reset water level detection electrode '+40 is set high, and the resistance value of the resistor 22a connected to the high water level detection electrode 14a is set low. has been done.

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 device is also energized. At the first 1υI stage of water supply, electrodes 14a, 14. for water level detection are installed. No water is in contact with either electrode b or 14G, and the resistance value of each electrode is close to infinite. Therefore, in this state, the oscillation circuit section 20 oscillates at the set oscillation frequency, and the load control section 16 is not operating, so the relay 17 does not operate, and the relay contact 17a
is closed to the N and C sides.

When the water level membrane T part 19 is set to a high water level, that is, when it is connected to the water level setting changeover switch 19a,
When the water supply continues and the water level reaches the upper part of the electrode 142L, the oscillation circuit section 20 is unable to maintain the set oscillation frequency, and the oscillation stops, or the oscillation voltage drops below the reference value. As the load decreases, the load control unit 16 operates, the relay 17 operates, the relay contact 17a switches to N, 0011I, the motor 6 is operated, the pulsator 4 rotates, and washing or rinsing is started. Ru. At this time,
When the water level drops below the position of 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.

If the water level falls below the water level reset detection electrode 140,
The oscillation circuit section 2Q oscillates at the set oscillation frequency, the load control section 16 becomes inactive, the relay 17 is opened, the relay contact 17a is closed again to the N and C sides, and the operation of the motor 6 is stopped. Then, the pulsator stops rotating 40 times.

Here, the width B of the iron core 1.1b is the −th and secondary winding 1
Since the winding widths A and A' of windings 1a and 110 are made thicker, the -th winding 11? The leakage magnetic flux from L can be suppressed to a minimum value.

Effects of the Invention As described above, according to the present invention, the primary winding of the rotary transformer for detecting water level detection signals, that is, the oscillation circuit side, is provided by winding or the like around an iron core made of a magnetic material such as ferrite. - It is possible to reduce the leakage magnetic flux from the secondary winding to the secondary winding, increase the degree of magnetic coupling, ensure the transmission of the water level detection signal, and enable accurate water level control. By providing an iron core made of a magnetic material on the side of the second winding, the magnetic influence of the washing/drying shaft can be ignored, and the cause of malfunctions can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a washing machine in an embodiment of the present invention;
FIG. 2 is an enlarged sectional view of the main part showing the installation state of the rotary transformer, and FIG. 3 is a professional drawing showing the basic configuration of the water level control device. 2nd...washbasin/dehydration tank, 3...outer tank, 11...rotating transformer,
112L - Next winding, 11b... Iron core, 11
C-- Secondary winding, 14a, 14b, 14C... Electrode (sensing section). Name of agent: Patent attorney Toshi Nakao Haga 1 person = 5
5 1 figure 0

Claims (2)

[Claims] (1) A detection section for detecting water level is provided at a predetermined position of a washing/dehydration tank whose surrounding wall, except for at least the upper end, is a non-porous wall, and a rotary transformer is provided for extracting the water level detection signal from this detection section to the outside through inductance coupling. Among the windings of this rotary transformer, the primary winding connected to the oscillation circuit is wound around an iron core made of magnetic material provided in the outer tank that contains the washing and dehydrating tank, and the secondary winding is connected to the washing and dehydrating tank. A water level detection device for a washing machine, which is installed in a dehydration tank and electrically connected to the detection section. (2) The water level detection device for a washing machine according to claim 1, wherein the width of the iron core around which the -secondary winding is wound is made wider than the winding width of the -secondary winding and the secondary winding.