JPS5991996A - Dc solenoid - 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 Industrial Application The present invention relates to a DC solenoid suitable for simultaneously operating a brake device, a drain valve, etc. in a washing machine, for example. Structure of conventional example and its problems Conventionally, A single-tank centrifugal dehydrating washing machine has a structure as shown in Figure 1, where 1 is an outer tank that receives washing water, and 2
1 is a washing and dehydrating tank provided inside an outer tank 1, a pulsator 3 is arranged at the inner bottom, and a large number of small holes 4 for draining water are bored in the peripheral side wall. Reference numeral 6 denotes a mechanical case, which 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 6 through a belt 7 and a pulley 8. 9 is a drain valve connected to the inner bottom of the outer tank 1, 10 is a brake arm, page 113 is a solenoid that pulls the drain valve 9 and the brake arm 1o, 12 is a support plate, and the outer tank 1, motor 6, mechanical case 5, etc. The outer tank 14 is suspended by a rod 13. 16 is a balancer provided at the top of the washing and dewatering tank, and 16 is a drain hose.

Next, the operation of the solenoid 11 will be explained using FIG. 2. 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 6.
is in pressure contact with the brake wheel 18 and can be detached from the brake wheel 18,
Perform braking action. The rotation of the brake wheel 18 is transmitted as the rotation of the washing and dehydrating tub 2. That is,
When the brake band 19 is pressed, 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
The built-in spring and brake spring 20
It is closed by the force of. Further, since the brake wheel 18 is pressed against the brake band 19 and does not rotate, the washing and dehydrating tub 2 does not rotate, and only the pulsator 3 rotates, allowing washing to be carried out.

During drainage and dewatering, the solenoid 11 is energized and the plunger 11-a of the solenoid 11 is attracted. The connecting member 17Fi connected thereto will move in the direction of the arrow. Therefore, when 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 3 and 4, these solenoids include a coil 11-a that generates a magnetic field, and a plunger 1 that is attracted and moves.
1-b, and a fixed iron core 11-C. And their characteristics can be listed as follows.

In the AC solenoid, the reactor 6 basis of the coil 11-a 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 11-a, regardless of the stroke. 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 11-a. Therefore, in single-tank centrifugal dehydrating washing machines,
It is common to use an AC solenoid.

However, 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 11-b being completely attracted, there is a risk of burnout. Beating is likely to occur when a gap occurs. As can be seen from these facts, in the case of an AC solenoid, it is necessary to completely attract the plunger 11-b and the fixed core 11-c, so plan 6 is used.
It is impossible to use a cushioning material to eliminate the impact noise between the base gear 11-b and the fixed core 11-c.

Furthermore, in the case of an AC solenoid, the acceleration of the plunger 11-b is larger and the impact is larger. Therefore, when an AC solenoid is used, a large impact sound is always generated, resulting in 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.

However, at present, the noise reduction structure of DC solenoids cannot be said to be perfect. In other words, if a cushioning material is provided between the plunger and the fixed core, the suction force and adhesion holding force will be significantly reduced.To prevent such a reduction, the wire type of the coil will be forced to increase. Also,
Due to this.

A rise in costs was unavoidable.

OBJECTS OF THE INVENTION The present invention solves these conventional problems and provides a direct current solenoid that can reliably have a silent structure at a low price comparable to or lower than that of an alternating current solenoid.

7. Structure of the Invention In order to achieve the above object, the present invention provides a ring-shaped groove on the outer periphery of a plunger that sucks a load and at a position that slides into contact with the inner surface of the cylinder, and in this groove, the plunger is operated. By fitting a sealing member that slides into the inner surface of the cylinder, when the plunger is sucked, the air inside the cylinder is compressed and gradually discharged to the outside through the gap between the sealing member and the inner wall of the cylinder, but suddenly Since it is not possible to discharge the liquid completely, the adsorption speed of the plunger is slow, and the adsorption is performed at a slow speed.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 6, reference numeral 21 denotes a connecting member that connects the load and the plunger 23 made of a magnetic material. 23 is a solenoid body made of a magnetic material, and inside it is a bobbin 3 with a coil 29 wound around its outer circumference that connects to the power terminal 28.
The center of the 0 pobin 3o containing 0 forms a cavity,
It constitutes the cylinder 30a, and the cylinder 30 described above
A plunger 23 is slidably installed at the point a. A cross section of approximately V
A ring-shaped groove 23-a is formed into which one end side of the ring-shaped seal member 31 is fitted.

Furthermore, the tip 23-b of the plunger 23 is attached to the end 32 of the fixed iron core 32 in the cylinder 30a during suction.
The outer peripheral end 31-a, which is the other end side of the seal member 31, is set to be in close contact with the cylinder.
It is set so as to be in sliding contact with the inner surface of the plunger 30a, and the outer peripheral end 31-a is oriented in the suction direction of the plunger 23.

FIG. 6 shows the cross-sectional shape of the seal member 31. As shown in FIG.

In the above configuration, the operation will be explained next. When the power is turned on, magnetism is generated by the current flowing through the coil 29, and the plunger 23 is drawn toward the fixed iron core 32. Then, as it approaches the fixed iron core 32, the suction force also increases, and the plunger 23 is accelerated to move closer to the fixed iron core 32.
However, the air inside the cylinder 30a is difficult to escape due to the presence of the seal member 31, and is only gradually exhausted to the outside. Therefore, plunger 23
The suction speed is reduced and the iron collides slowly with the fixed iron core 32, so no collision noise is generated. When the plunger 23 is attracted, the air inside the cylinder 30a has already been exhausted to the outside, so the pressure is equal to that of the outside air, and the reaction force that separates the attraction force becomes 0.
Therefore, there is no loss after adsorption, and sufficient adsorption force can be obtained with a small amount of current.

On the other hand, when the seal member 31 has a substantially V-shaped cross section, its elasticity is effective and uniform sliding can be obtained without being affected by changes in the inner diameter, inner surface condition, etc. of the cylinder 30a. Of course, even a ring-shaped sealing member with a roughly round cross-section can be used and will still have the intended effect, but mass production installations taking into account variations in processing accuracy, etc. It is preferable to use a sealing member 31 having a substantially V-shaped cross section.

Moreover, since the sealing member 31 comes into sliding contact with the inside of the cylinder 30a each time it moves in and out of the plunger 23, it can be expected that the sealing member 31 will wear out quickly and the sealing effect will not last long. Therefore, as shown in FIG. 7, if a member 31-b with good lubricity such as Teflon is attached to the sliding contact portion of the seal member 31 with the inner surface of the cylinder 30a, or if it is fixed by baking or the like, the seal member It is possible to obtain a material with good lubricity while effectively maintaining the elasticity of No. 31. In addition, the above-mentioned pasting method is not the same, but it can be done by mixing Teflon material into the base material of the sealing member itself, for example, a rubber material, or by mixing molybdenum disulfide, wax, etc. as necessary. Therefore, it is possible to improve the lubricity, obtain a highly durable sealing member, and furthermore provide a DC solenoid having stable shock absorbing and sound damping properties over a long period of time.

In addition, since the outer peripheral end 31-a of the sealing member 31 faces in the suction direction of the plunger 23, it enhances the airtight effect with the inner surface of the cylinder 30a when the plunger 23 is pulled. does not exhibit any sealing effect and can be quickly restored.

Effects of the Invention As is clear from the above embodiments, according to the present invention, a sealing member is effectively provided between the plunger and the inner surface of the cylinder. , the suction speed of the plunger is reduced, and therefore the plunger is attracted very slowly, making it possible to obtain a silent type DC solenoid without producing any collision noise. Furthermore, there is no risk of a decrease in output, and there is no need to take special measures to increase output, which is advantageous in terms of cost.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional washing machine with a dewatering and drying function (single-tank type) equipped with a solenoid, Figure 2 is a plan view of the missing part of the washing machine near the solenoid, and Figure 3 is a conventional FIG. 4 is a cross-sectional view of the solenoid, FIG. 5 is a cross-sectional view of the DC solenoid in an embodiment of the present invention, FIG. 6 is a cross-sectional view of the seal member, and FIG. 7 is a cross-sectional view of the seal member. FIG. 7 is a sectional view showing another embodiment. 23...Plunger, 30a...Cylinder. 31・River・Seal member, 31-a・・River・Outer peripheral end, 3
1-b... Member having lubricity. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 5
Figure 6j 521

Claims (1)

[Claims] (1) A ring-shaped groove is formed on the outer periphery of the plunger at a position where it slides inside the cylinder during operation, and the inner surface of the cylinder slides into contact with the groove when the plunger operates. A DC solenoid fitted with a sealing member. @) The DC solenoid according to claim 1, wherein the seal member has a substantially V-shaped cross section, one end of which is fitted into the groove of the plunger, and the other end of which is in sliding contact with the inner surface of the cylinder. . (3) The DC solenoid according to claim 1 or 2, wherein a member with high lubricity is provided in the sliding portion of the seal member. (4) The DC solenoid according to claim 1 or 2, in which a highly lubricating material is mixed into the base material constituting the seal member. shape and absence,
2. The direct current solenoid according to claim 1, wherein the tip of the portion that slides into contact with the inner surface of the cylinder is oriented in the suction direction of the plunger.