JPS59188105A - Solenoid - Google Patents

Abstract

PURPOSE:To enable to silence the retracting sound of a plunger by an air damper effect at the suction time and to reduce an air damper effect at the exteding time by allowing a space for the air damper which faces the end face of the plunger at the retracting side to communicate with the atmospheric air. CONSTITUTION:A bobbin 22 and a plunger 25 are sealed by a sealing memer 26, and the bobbin 22, the plunger 25, the member 26 and a stationary core form a space 28 for an air damper. The space 28 communicates only by a passage 24 of the core 23 to flow the air in and out. The speed of the retracting plunger 25 is higher than that of the extending plunger,the air cannot suffieicntly follow through the passage 24 to the movement of the plunger 25. Accordingly the air damper effect does not considerably decrease. Since the movement of the plunger 25 due to a connecting load at the extending time is slower than that at the retracting time, the inflow of the air can follow through the passage 24. Consequently, the air damper effect can be remarkably reduced at the time of extending the plunger 25.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solenoid with high noise reduction effect.

Conventional configurations and their problems Conventionally, solenoids have configurations as shown in FIGS. 1 and 2. 1 is a plunger with a movable iron core, 2 is a frame, and 31 is a fixed iron core, and a magnetic path is formed by these. 4 is a coil that generates a magnetic field, and bobbin 5
wrapped around. Reference numeral 6 denotes a rubber ring as a sealing member, which is fitted into the plunger and controls the inflow and outflow of air. In this case, the air inside the bobbin 5 is sealed by the granger 1, the frame 2, the fixed iron core 3, the bobbin 5, and the rubber ring 6. With this configuration, when the coil 4 is energized, the plunger 1 is attracted, the space volume within the bobbin 5 is reduced, and the internal pressure is increased. Then, the comb ring 6 is deformed, and air gradually escapes from the gap with the plunger 1.

Therefore, the movement of the plunger 1 is suppressed by the air resistance, the moving speed of the plunger 1 is slowed down, and the momentum at the time of collision with the fixed iron core 3 is reduced, so the collision noise is reduced. In this way, in a solenoid equipped with a seal member such as the rubber ring 6, there is a noise reduction effect due to the air damper. Further, after the attraction, there is no difference between the internal pressure and the external pressure, and the plunger 1 is no longer subject to the force of the air, so the magnetic field generated by the coil is effective only against the load.

However, in the above configuration, when the coil 4 is de-energized, the air damper effect works even when the plunger 1 moves away from the fixed iron core 3 due to the connected load. Therefore, when the fitting distance between the plunger 1 and the rubber link 6 is large and the air damper effect is large, or when the connection load is small, the return of the connection load becomes very difficult. In particular, considering dimensional variations during mass production of rubber products, it is extremely difficult to secure a fitting allowance that increases the air damper effect during suction and reduces the air damper effect during disengagement. there were.

Here, a case where it is inconvenient if the return of the connected load is poor upon disconnection will be explained using a single-tub centrifugal dewatering washing machine as an example. In FIGS. 3 and 4, 7 is an outer tank that receives 6L of water, 8 is a washing and dewatering tank provided inside the outer tank 7, and a pulsator 9 is provided at the bottom.

The mechanical case 1o has a mechanism that transmits the drive of the motor 11 so that only the pulsator 9 is rotated during washing, and the washing and dehydration tank 8 is rotated during dehydration. Furthermore, the motor 11 is connected to the mechanical case 1 by means of a belt 12 and a pulley 13.
It transmits power. 14 is a drain valve for the outer tank; 15 is a brake arm; these are pulled by a solenoid 16 via a rod 17. The drain valve 14 has a built-in drain valve spring 18, and its force closes the drain valve 14. Next, a brake spring 19 is attached to the brake arm 15. Therefore, solenoid 16
During suction, it is necessary to overcome the force of the drain valve Suge V/g 18 and the brake spring 19, so a considerably large force is required. However, at the time of detachment, it tries to return due to the reaction force of the drain valve spring 18 and brake spring 19, which are connected loads, but since springs are used, the force becomes weaker as it returns. Therefore, the return speed when the brake is effective or the drain valve 14 is closed is slow, and the final spring force is small, resulting in a situation where the brake is not effective or the drain valve 14 cannot be closed reliably. In the example of use in a single-tank centrifugal dehydrating washing machine, it is desirable to have an air damper effect.

OBJECTS OF THE INVENTION It is an object of the present invention to solve such conventional problems and to provide a solenoid that can eliminate suction noise by an air damper effect during suction, and reduce the air damper effect when detached.

Structure of the Invention In order to achieve the above object, the solenoid of the present invention includes a bobbin around which a coil is wound, and a plunger which is slidably disposed in a central space of the bobbin and is attracted into the central space by energizing the coil. , a sealing member disposed between the plunger and the periphery of the central space, and the air damper space facing the suction side end face of the plunger is communicated with the outside air, and this communication allows the air damper space to communicate with the outside air when the plunger is suctioning. The air damper effect is changed depending on when the vehicle leaves the vehicle and when the vehicle leaves the vehicle.

Description of examples Embodiments of the present invention will be described below based on the accompanying drawings.

In FIG. 5, reference numeral 21 indicates a fixed iron core 23 wound around a bobbin 22, which is attached to one end of the bobbin 22, and has a communication portion 24 provided approximately in the center thereof. A plunger 25 has a movable iron core inserted into the bobbin 22 and comes into contact with the fixed iron core 23 during suction. Reference numeral 26 denotes a sealing member such as a rubber ring attached to the end of the pobbin 22 on the reflective side of the fixed core 23, and is in close contact with the circumferential surface of the plunger 25. Reference numeral 27 denotes a frame for mounting the bobbin 22 from the outside. Here, bobbin 22 and plunger 2
5 is sealed by a sealing member 26, and the bobbin 22
．． Plunger 25. The seal member 26 and the fixed core form an air damper space 28. This air damper space 28 is communicated only through the communication portion 24 of the fixed iron core 23. Air flow occurs through this communication portion 24.

Next, the force applied to the plunger 25, for example in a washing machine, is of two types: tension a caused by a load such as a spring, and attraction force a caused by magnetism generated in a coil. In Fig. 6, if the horizontal axis is the distance 2 between the plunger 25 and the fixed iron core 23, and the vertical axis is the spring tension d and the magnitude of the attraction force F, then the spring tension d is linear. Changes to

On the other hand, the suction force of the solenoid 18 is always greater than the tension a, and changes so that the smaller the interval 2, the greater the difference from the tension a of the spring. Therefore, the plunger 25
The speed at which it is adsorbed is greater than the speed at which it leaves.

Due to this speed difference, with respect to the movement of the plunger 25,
The state of air inflow and outflow changes during suction and withdrawal. That is, during suction, the outflow of air through the crest 24 cannot sufficiently follow the movement of the plunger 25, so the air damper effect does not decrease much. On the other hand, during disengagement, the movement of the plunger 25 due to the connected load is slower than during suction, so the inflow of air through the communication portion 24 can follow. Therefore, when the plunger 25 is removed, the air damper effect is significantly reduced.

Here, depending on the relationship between the specifications of the solenoid and the size of the connected load, the communication part 2 can obtain the above effects.
The optimum opening area of 4 can be easily set as described above in the communication section 24.
By providing this, the air damper effect is not significantly reduced during suction and the silencing effect is maintained, and when the air damper is removed, the air damper effect is significantly reduced and the attached load can be removed at a sufficient speed.

FIG. 7 shows another embodiment of the present invention in which the communication portion is connected to the frame 27.
This is provided by a combination of the hole 29 provided in the bobbin 22 and the 3° angle. Since the frame 27 is made of a magnetic material, it is generally made by pressing. in this case,
Due to the nature of the punch, it is difficult to make very thin holes. Therefore, by combining the hole 3o of the resin bobbin and the hole 29 of the frame in order to obtain a small hole, it is possible to freely set a communication portion with a necessary area. Furthermore, in this case, the process of drilling holes in the fixed iron core 23 is added in the embodiment shown in FIG. Therefore, it is advantageous in terms of cost.

FIG. 8 shows still another embodiment, in which a groove 32 communicating with the outside is provided in a part of the tip 31 of the bobbin 22', thereby forming a communicating portion. Here, similar to the embodiment shown in FIG.
Since the groove 32 can be provided when forming the bobbin 22,
Reasonable. Furthermore, it is a very simple and advantageous method because it allows a free opening area and shape to be obtained during molding, and there is no need to make adjustments during assembly.

In addition, in the above embodiment, the fixed iron core 23, the frame 27,
Although holes and grooves are provided in the bobbin 22 to serve as communication portions, the point is that any component for sealing the inside of the bobbin 22 may be provided with a communication portion that communicates with the outside.

Effects of the Invention As is clear from the above embodiments, the solenoid of the present invention has a silencing effect due to the air damper effect during suction, and reduces the air damper effect when disconnected, causing a negative impact on the connected load. It is possible to prevent this from happening.

[Brief explanation of drawings]

Figure 1 is a perspective view of a conventional solenoid, Figure 2 is a sectional view of the same, Figure 3 is a sectional view of a single-tub centrifugal dewatering washing machine using a solenoid, and Figure 4 is the drain valve of the same washing machine. FIG. 5 is a sectional view of a solenoid showing an embodiment of the present invention. FIG. 6 is a diagram showing the relationship between the gap between the plunger and the fixed core and the force acting on the plunger. FIG. 7(a) is a sectional view of a solenoid showing another embodiment of the present invention, and FIG.
8 is a sectional view of a solenoid showing still another embodiment. 21... Coil, 22... Bobbin, 2
4...Communication part, 25...Plunger,
26... Seal member. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 (0-) 21 Doza

Claims (1)

[Claims] In the bobbin where the coil is fully wound and the central space of this bobbin,
A plunger that is slidably arranged and is attracted into the central space by energizing the coil, and a sealing member that is arranged between the plunger and the periphery of the opening of the central space,
The air damper space facing the suction side end face of the plunger is a solenoid that communicates with outside air.