JPH0324764B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a solenoid for a washing machine that simultaneously operates the brake device, drain valve, etc. of the washing machine.

Conventional structure and its problems Conventionally, in a single-tub centrifugal dehydrating washing machine, the first
It has a structure as shown in the figure. Reference numeral 1 denotes an outer tank for receiving washing water, and 2 a washing and dewatering tank provided inside the outer tank 1, which has a pulsator 3 at the bottom and a large number of small holes 4 for draining water on the side wall. The mechanical case 5 has a mechanism for transmitting the drive of the motor 6 so as to rotate only the pulsator 3 during washing, and to rotate the washing and dehydrating tub 2 during dehydration. The motor 6 transmits drive to the mechanical case 5 through a belt 7 and a pulley 8. 9 is a drain valve of the outer tank 1, 10 is a brake arm, and 11 is a drain valve 9 and a brake arm 10.
Solenoid 12 is a support plate that pulls the outer tank 1,
The motor 6, mechanical case 5, etc. are arranged, and the rod 1
3 is hooked to the outer tank 14. 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 drain valve 9 is connected to the drain valve 9 via a connecting member 17. There are a brake wheel 18 and a brake band 19 inside the mechanical case 5, and the brake band 19 is connected to the brake wheel 1.
It can be press-contacted and detached from 8 and performs a braking action.
The rotation of the brake wheel 18 is transmitted to the rotation of the washing and dehydrating tub 2. That is, when the brake band 19 is pressed against the brake wheel 18, the brake wheel 18 does not rotate, and the washing and dehydrating tub 2 also does not rotate. During washing, the solenoid 11 is not energized, so the drain valve 9 is connected to the built-in spring and brake spring 2.
Closed with 0 force. Also brake wheel 18
is in pressure contact with the brake band 19 and does not rotate, so the washing/dehydration tub 2 does not rotate, and only the pulsator 3 rotates to perform washing. During drainage and dewatering, the solenoid 11 is energized, the plunger 11a of the solenoid 11 is attracted, and the connecting member 17 connected thereto moves in the direction of the arrow.
Therefore, 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 Figures 2 to 4, these solenoids are composed of a coil 11a that generates a magnetic field, a plunger 11b that moves when attracted, and a fixed iron core 11c. has been done. 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 coil 11
The steady current is determined only by the DC resistance of a. 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, relative to the amount of copper in the coil 11a. Therefore, AC solenoids are commonly used in single-tub centrifugal washing machines. but,
In an AC solenoid, the current value changes depending on the stroke, so if a voltage is applied for a long time without the plunger 11b being completely attracted, there is a risk of burnout. Furthermore, since alternating current is used, beats are likely to occur when there is a slight gap. As you can see from these things, in AC solenoids,
Since the plunger 11b and the fixed core 11c must be completely attracted to each other, it is impossible to use a buffer material to eliminate the impact noise between the plunger 11b and the fixed 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, resulting in noise.
DC solenoids are more advantageous in terms of performance because they do not have the above-mentioned problems and can have a quiet structure. However, as mentioned above, single-tank centrifugal washing machines have a stroke of 10 mm or more, have a large load, and are continuously energized for several minutes or more during draining and spin-drying, so direct current is required to satisfy the suction power and temperature rise. When making a solenoid, coil 11a
becomes a very large thing. Since the magnetomotive force is determined by the wire diameter of the copper wire of the coil 11a, a considerably thick wire diameter must be used in order to attract a predetermined load. Also, in order to maintain the power, it is necessary to keep the power down to about 10 watts, so the resistance value must be quite large. Therefore, the amount of copper in the coil 11a is extremely large, and the price is several times higher than that of an AC solenoid.

OBJECTS OF THE INVENTION In view of the above-mentioned conventional problems, an object of the present invention is to provide a solenoid for a washing machine that has a simple structure and is capable of reducing noise during suction.

Structure of the Invention The solenoid for a washing machine of the present invention has a circumferential groove near the opening of the cylinder portion of the bobbin where the plunger retracts, and a sealing member is fitted into the circumferential groove so that the inner circumferential piece of the sealing member is moved toward the back of the cylinder portion. It faces towards the outside of the plunger and is always in sliding contact with the outer periphery of the plunger, thereby slowing down the suction speed of the plunger by sealing the air inside the cylinder.

DESCRIPTION OF EMBODIMENTS A DC solenoid according to an embodiment of the present invention is shown in FIG. That is, 21 is the load and the plunger 22
This is a connecting member in which the two are connected by a fixing pin 23. 24
The solenoid outer frame is open on the load side, and is closed and fixed to the outer frame 24 with a lid 25 having a circular hole in the center. The tip of the plunger 22 has a concave portion 22a, and the convex portion 2 of the fixed iron core 26 that is opposite to this has a concave portion 22a.
6a. plunger 2
2 is surrounded by a cylinder part 29a of a bobbin 29 around which a coil 28 connected to an external power supply terminal 27 is wound, and the inner part thereof is sealed by the fixed iron core 26. A suction plate 30 is attached to the connecting member 21 via an auxiliary suction plate 31 and comes into elastic contact with the lid 25. A circumferential groove is formed near the opening of the cylinder portion 29a of the bobbin 29 by a ring-shaped groove portion 29b and the center hole of the lid 25. A ring-shaped sealing member 32 having a substantially V-shaped cross section is fitted into the circumferential groove,
The inner end of the inner circumferential piece 32a faces toward the back of the cylinder portion 29a and is in sliding contact with the outer circumference of the plunger 22.

The operation in the above configuration will be explained. When the power is turned on, a current flows through the coil 28 to generate magnetism, and the plunger 22, which has been pulled out by the tensile force of the load, is attracted to the inner part of the cylinder portion 29a. The suction force is applied to the fixed iron core 26 by the plunger 22.
becomes stronger as it approaches. Therefore, the plunger 22
is accelerated and about to collide with the fixed iron core 26.
However, the plunger 22 is in the cylinder portion 29a.
Once inside, the air inside is difficult to escape due to the sealing member 32 and is only gradually exhausted to the outside. Therefore, while the plunger 22 maintains its accelerating force, the suction speed is rapidly slowed down by the action of the air damper.
It slowly collides with the fixed iron core 26 and enters an adsorption state, and the impact noise at that time is alleviated. After adsorption, the internal pressure and the outside air become completely equal, so no counter-suction force is exerted and no loss of adsorption force occurs.
When the adsorption is finished (the current is cut off), the plunger 22 is pulled out of the cylinder part 29a by the tensile force on the load side. Because of this, outside air can be brought in quickly, and problems such as delays in load-side operation will not occur. Furthermore, since the inner circumferential piece 32a faces toward the back of the cylinder portion 29a, the air inside the cylinder portion can be easily blocked, and the effect of an air damper can be easily produced. and plunger 22
is oriented in the direction of smooth entry, which has the effect of making the movement smoother.

Note that the seal member 32 is designed to improve sliding properties.
Durability can be ensured by attaching a member with good lubricity such as Teflon to the inner peripheral piece 32a, or by molding the sealing member 32 itself with a rubber base material mixed with a lubricant such as Teflon, wax, or molybdenum disulfide. It can enhance the silencing effect.

Effects of the Invention As described above, in the washing machine solenoid of the present invention, the sealing member is fitted into the circumferential groove of the opening of the cylinder portion, and the inner circumferential piece of the sealing member faces toward the back of the cylinder portion, and the plunger Because it is in sliding contact with the outer periphery, the plunger can move slowly when suctioning and quickly when separating. As a result, it is possible to completely eliminate the sound during suction, which is a problem with conventional methods, without loss of suction force and with a simple configuration, making it possible to provide an inexpensive and small AC or DC solenoid. effective.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a single-tank dehydrating washing machine, Figure 2
3 is a perspective view of a DC solenoid, FIG. 4 is a sectional view thereof, and FIG. 5 is a sectional view of a DC solenoid according to an embodiment of the present invention. 22... Plunger, 26... Fixed iron core, 28... Coil, 29... Bobbin, 29a... Cylinder part, 29
b...Groove (circumferential groove), 32...Seal member, 32a...
Inner circumference piece.

Claims (1)

[Claims] 1. A bobbin with a coil wound around its circumferential surface and one end of the cylinder part sealed, a plunger slidably inserted into the opening side of the cylinder part of the bobbin, and a plunger inside the opening of the cylinder part. A solenoid for a washing machine, comprising: a sealing member that is fitted into a circumferential groove formed so that an inner circumferential piece faces toward the back of the cylinder portion and slides into contact with a circumferential surface of the plunger.