JPH0355160B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric washing machine in which a drain valve, a brake device, etc. are operated by a direct current solenoid.

Conventional structure and its problems Conventionally, in a single-tub centrifugal dehydrating washing machine, the first
The structure is as shown in the figure. 1 is an outer tank that receives washing water, 2 is a washing/dehydration tank installed inside the outer tank 1, and a pulsator 3 is installed at the bottom, and a large number of water drains are installed on the side wall. A small hole 4 is provided. Reference numeral 5 denotes a mechanical case, which has a mechanism for transmitting the driving force of a motor 6 so as to rotate only the pulsator 3 during washing, and to rotate the washing and dewatering tank 2 during dehydration. Further, the motor 6 transmits driving force to the mechanical case 5 through a belt 7 and a pulley 8.

9 is the drain valve of the outer tank 1, 10 is the brake arm,
11 is a solenoid that pulls the drain valve 9 and the brake arm 10; 12 is a support plate on which the outer tank 1, motor 6, mechanical case 5, etc. are arranged; these are suspended from the outer tank 14 by rods 13; ing.
15 is a balancer provided at the top of the washing and dewatering tank, and 16 is a drain hose.

Furthermore, the operation of the solenoid 11 will be explained using FIG. The solenoid 11 is connected to the drain valve 9 via a connecting member 17. Mecha case 5
There are a brake wheel 18 and a brake band 19 inside the brake wheel 18, and the brake band 19 can be press-contacted to and detached from the brake wheel 18 to perform a braking action. The rotation of the brake wheel 18 is transmitted to the washing and dehydrating tub 2 as rotational force. In other words, when the brake band 19 is pressed, the brake wheel 18 does not rotate and the washing and dehydration tank 2
It doesn't rotate either. During washing, the solenoid 11 is not energized, so the drain valve 9 is operated by a built-in spring (not shown) and the brake spring 2.
Closed with 0 force. Also, brake wheel 18
Since it is pressed against the brake band 19 and does not rotate, the washing and dewatering tub 2 does not rotate, and only the pulsator 3 rotates, allowing washing to be carried out. During drainage and dehydration, the solenoid 11 is energized and the plunger 11b of the solenoid is attracted. The connecting member 17 connected thereto will move in the direction of arrow A. Therefore, as the drain valve 9 opens, the brake arm 10 rotates, and the brake band 19 separates from the brake wheel 18, resulting in a dewatering operation.

As described above, the solenoid 11 is used to open and close the brake device and the drain valve 9 of the washing and dewatering tank 2.

There are two types of solenoids: AC solenoids and DC solenoids.As shown in Figure 2, these solenoids consist of a coil 11a that generates a magnetic field, a plunger 11b that is attracted and moves, and a fixed iron core 11c that is fixed.
It is composed of. And their characteristics can be listed as follows.

In the AC solenoid, the reactance of the coil 11a is extremely large compared to the resistance, so the current changes depending on the stroke. At this time, the larger the stroke, the larger the current flows. On the other hand, in a DC solenoid, the steady current is determined only by the DC resistance of the coil 11a, regardless of the stroke. Also, the attractive force is determined by the magnetomotive force, which is given by the product of the current and the winding. Therefore, the AC solenoid can handle a large load with a larger stroke than the DC solenoid compared to the amount of copper in the coil 11a.

However, in an AC solenoid, the current value changes depending on the stroke, so the plunger 11
If a voltage is applied for a long time without complete adsorption of b, there is a risk of burnout. In addition, since alternating current is used, beats are likely to occur when there is a slight gap. As can be seen from these facts, in the AC solenoid, the plunger 11b and the fixed iron core 11c
Since it is necessary to completely absorb the
It is impossible to use a cushioning material to eliminate the impact noise between the fixed iron core 11c and the fixed iron core 11c. Furthermore, with the AC solenoid, the acceleration of the plunger 11b is greater and the impact is greater. Therefore, when an AC solenoid is used, a large impact sound is always generated and becomes a source of noise.

DC solenoids do not have the above-mentioned problems and have a quiet structure, so DC solenoids are more advantageous in terms of performance.

Here, solenoid 1 of the single-tank centrifugal dehydrating washing machine
Looking at 1, the required stroke is 10mm or more. Further, the load is quite large because it needs to overcome the built-in spring of the drain valve 9 and the brake spring 20. Furthermore, in an electric washing machine, electricity is continuously applied for several minutes or more during draining and spin-drying, so if a DC solenoid that satisfies the above-mentioned suction force and temperature rise is to be created, the coil 11a will be extremely large. This is because the magnetomotive force is determined by the wire diameter of the copper wire of the coil 11a.
In order to attract the specified load, a fairly thick wire diameter must be used, and in order to maintain the suction state, the electric power must be kept to about 10 watts or less, so the resistance value must be considerably large. Because it has to be.

Therefore, the amount of copper in the coil 11a of the DC solenoid becomes extremely large, making it several times more expensive and occupying a larger space than an AC solenoid of comparable capacity. In electric washing machines,
Since it is used in general households, there is a strong demand for low-cost products, and as shown in Figures 1 and 2, there are various parts on the bottom of the outer tank 1, so it does not take up too much space. Therefore, it is difficult to use a DC solenoid like the one above. On the other hand, as mentioned above, AC solenoids are generally used in electric washing machines because they can handle a large load with a relatively large stroke.

However, as mentioned above, electric washing machines are used in general households, so it is desirable to suppress noise as much as possible. Noise countermeasures are especially important since the equipment is used at night. Nevertheless, as mentioned above, AC solenoids cannot have a silent structure, so they essentially become a source of vibration.

In the past, some measures have been taken in which the entire AC solenoid is covered with a cover, but this cannot be a fundamental measure and a sufficient effect cannot be obtained.

As described above, the problems with conventional electric washing machine solenoids are that DC solenoids are expensive, and AC solenoids cannot provide a silent structure.

OBJECTS OF THE INVENTION The present invention solves these conventional problems and provides an electric washing machine in which the impact noise of the solenoid when driving the drain valve is extremely small.

Structure of the Invention In order to achieve the above object, the present invention has the following features:
It has a low-resistance suction coil, a high-resistance holding coil, and a changeover switch, and is equipped with a DC solenoid that switches between the coils used during suction and holding, and eliminates solenoid collision noise. It is designed to be extremely small and to reduce the amount of power consumed by the solenoid when holding the plunger.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In Figures 3 and 4, 2
1 is a main switch, 22a is a plunger suction coil, and 22b is a plunger holding coil.The resistance value of the suction coil 22a is smaller than that of the holding coil 22b. 23 is a changeover switch that opens and closes when the plunger is sucked and when the plunger is held.

The attraction coil 22a is a low-resistance coil using a copper wire with a large wire diameter and low resistance, and a large current is passed in a short time to increase the magnetomotive force to ensure a predetermined attraction force. Here, the suction coil 2 with such specifications
If only 2a is used to maintain electricity for a long time, the electric power value is large and the temperature rise cannot be suppressed, resulting in burnout.

On the other hand, the holding coil 22b is a high-resistance coil using a high-resistance copper wire with a small wire diameter. Therefore, the current when voltage is applied is very small,
The power is low, around 10 watts, and can withstand continuous electricity. Furthermore, in the case of holding, since the stroke is 0 mm, even with a very small magnetomotive force, the attractive force is large and holding is possible. However, suction is not possible where the stroke is large.

Using the above changeover switch 23, both coils 2
By switching between using 2a and 22b for suction and holding, it is possible to pull a load with a large suction force during suction, and to hold the load with low power during holding. Moreover, since the wire diameter of the copper wire can be selected to suit both suction and retention, the amount of copper can be extremely reduced.

Now, considering the circuit configuration, a normally closed changeover switch 23 is connected in parallel to the holding coil 22b, and an attraction coil 22a is connected in series to this parallel circuit. The main switch 21 then opens and closes the power to the DC solenoid.

The changeover switch 23 is configured to be changed over by the movement of the plunger 11b. In other words, the auxiliary plate 24 moves simultaneously with the plunger 11b when energized.
presses the actuator 25 which is interlocked with the changeover switch 23, and the changeover switch 23 is switched to the open state. Further, when the power supply is stopped, the plunger 11b returns due to the load, the actuator 25 also returns, and the changeover switch 23 becomes in the closed state.
Note that 26 in FIG. 3 is a cushioning material.

To explain the operation in the above configuration, during suction, the changeover switch 23 is in the closed state,
Since the holding coil 22b is short-circuited, voltage is applied only to the attraction coil 22a. Therefore, as described above, a large suction force can be obtained.

Next, during holding, the post-attraction changeover switch 23 is in an open state, so a voltage is applied to both ends of the series-connected attracting coil 22a and holding coil 22b, resulting in a holding state. Here, during holding, the attraction coil 22a and the holding coil 22b are connected in series and put into the circuit.
This is to effectively use the DC resistance component and the number of turns. By doing so, the amount of copper in the holding coil 22b can be effectively reduced.

Furthermore, as another embodiment, the suction coil 2
2a and the holding coil 22b are connected in parallel and one of them is selectively switched, or a timer is used and the changeover switch 23 is switched with a time lag after the plunger is attracted.

Since the above-mentioned DC solenoid can significantly reduce the amount of copper, it can be provided at a price equal to or lower than that of an AC solenoid, and thus can greatly contribute to lowering the cost of electric washing machines. Furthermore, since it is a DC solenoid, a buffer material 26 is used, and the plunger 1
1b can be prevented from colliding strongly and a quiet structure can be achieved.

Although the embodiments have been described using a single-tub type washing machine for both dehydration and dehydration as an example, it goes without saying that the present invention can be implemented in a two-tub type washing machine that has a washing tub and a dehydration tub separately.

Effects of the Invention As is clear from the above embodiments, according to the present invention, the drain valve is driven by a DC solenoid that can switch the coil used for suction and holding, and is inexpensive. It has great effects, such as low operating noise and the ability to reduce the amount of power used during holding.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of a conventional washing machine with dehydrating function, Fig. 2 is a partially cutaway plan view of the vicinity of the solenoid, Fig. 3 is an external perspective view of a DC solenoid in an embodiment of the present invention, Figure 4 is the same electrical circuit diagram. 9...Drain valve, 11...Solenoid, 22a...
...Suction coil, 22b...Holding coil, 23
...changeover switch.

Claims (1)

[Claims] 1 has a DC solenoid that opens and closes a drain valve communicating with the washing tub, and the DC solenoid has a plurality of coils having different resistance values, a changeover switch that selects and operates a specific coil among the plurality of coils, and the and a plunger that is attracted and held when the coil is energized, and the changeover switch is switched between when the plunger is attracted and when the plunger is held, and the resistance value of the coil selected during attraction is set higher than that of the coil selected when held. An electric washing machine with a small setting.