JPS62166502A - Solenoid - Google Patents

Abstract

PURPOSE:To obtain a silencing type solenoid which effectively attenuates a metallic impact sound generated at energization time by attenuating the impact force of a movable core to a passive core by the elasticity of a leaf spring and a frictional force generated between the walls of the legs of the spring. CONSTITUTION:A movable core 7 is energized by a reset coil spring 9 in the state that a coil 4 is not energized to form a predetermined gap between the core 7 and a passive core 8. When the coil 4 is energized, an electromagnetically attracting force is generated between the core 8 and the core 7. Since the core 8 cannot move leftward by spring means 12, the core 7 moves rightward against the spring 9 to collide with the core 8. Leaf springs 13 which form the spring means 12 are deflected by the impact force to remove the contacting surfaces. That is, distributed frictional forces are generated along the contacting surfaces of the springs 13 to become thermal energy, thereby varnishing the collision energy. This energy is proportional to the total contacting area of the springs 13 to attenuate the collision sound by the elasticity and the frictional heat energy of the springs 13.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a solenoid, and more specifically, to a noise-reducing solenoid that suppresses the try sound of a plunger during one energization operation as low as possible. .

[Technical Background of the Invention Cotlenoids are used as actuators in various electronic and electrical devices, but when this type of solenoid is energized, the movable core (plunger) is electromagnetically attracted and violently collides with the fixed core. Generates a metallic impact sound.

Although such metallic noise is not much of a problem in industrial equipment, it is often annoying in equipment used in offices and homes.

Therefore, conventionally, for example, a cushioning material made of rubber, plastic, or the like is interposed between the movable core and the fixed core. However, since this is merely an elastic buffer, it does not provide sufficient attenuation against impact. Furthermore, since a gap is left due to the presence of the cushioning material, there is a drawback that the maximum suction force is reduced.

[Object of the Invention] This invention was made in view of the above-mentioned drawbacks of the conventional art.
The purpose is to provide a noise-muffling solenoid having a structure that can effectively attenuate metallic impact noise generated during energization.

[Examples] Hereinafter, the present invention will be described in detail with reference to embodiments shown in the accompanying drawings.

As illustrated in FIGS. 1 and 2, this solenoid includes a housing 1 having a substantially cylindrical shape.

In this embodiment, the housing 1 includes an outer yoke part 2 formed in a cylindrical shape with a bottom, and a front yoke part 3 fitted into an opening of the outer yoke part 2. Through holes 2a and 3a of the same diameter are coaxially bored in the yoke part 3, respectively.

Inside the housing 1, a coil 4 is wound around a bobbin 5, and the air core 6 thereof is arranged in communication with the through holes 2a, 3a. A movable iron core (plunger) 7 and a passive iron core 8 are each slidably inserted into the air core portion 6 of the coil 4 .

The movable iron core 7 passes through the through hole 3a of the front yoke part 3 and protrudes outside the housing 1, and the locking pin 10 of the return coil spring 9 passes through its front end 7a. In addition,
The rear end portion 7b of the movable iron core 7 is formed into a conical shape. The passive iron core 8 is arranged to face the rear end 7b of the movable iron core 7, and one end 8a facing the rear end 7b is a conical recess. On the other hand, the other end 8b of the passive core 8 can protrude from the through hole 2a of the outer yoke part 2, and a boss 11 for caulking and fixing is provided protruding from the other end 8b.

In this invention, the passive core 8 is supported by the housing 1 via spring means 12. According to this embodiment, the spring means 12 includes, as shown in FIGS. 3 and 4, a plurality of truncated conical leaf springs 13 each having a foot wall 13a extending in the form of a pile. It consists of layers that are closely bonded together. The top wall of each leaf spring 13 has a mounting hole 13 for the passive iron core 8.
b is formed, and this mounting hole 13b is formed in the boss 11.
By fitting and caulking the boss 11, the spring means 12 is integrally attached to the passive iron core 8.

On the other hand, the housing 1 is provided with a seat 14 for supporting the spring means 12. In this example,
The catch seat 14 is made by bending a part of the outer yoke part 2 forming the housing 1 so as to embrace the plate spring 12 as shown in the figure. A through hole 14a for caulking is provided.

Next, the present invention will be explained in detail. First, when the coil 4 is not connected to the movable core 7, the movable core 7 is biased toward the left in FIGS. 1 and 2 by the return coil spring 9. A gap is formed. Next, when the coil 4 is energized, an electromagnetic attractive force is generated between the passive iron core 8 and the movable iron core 7. In this case, since the passive core 8 cannot move to the left by the spring means 12, the movable core 7 moves to the right against the return coil spring 9 and collides with the passive core 8. Each of the leaf springs 13 constituting the spring means 12 is bent by this collision force, and a displacement occurs at each of their contact surfaces due to shear force. That is, this collision generates a distributed normal force f (see Figure 3) on each leaf spring 13, so if the friction coefficient of the contact surface is μ, a distributed friction force μf is generated along the contact surface. , this becomes thermal energy and dissipates the collision energy.

This energy is proportional to the total contact area of the leaf springs 13, and the impact sound is attenuated by the elasticity of the leaf springs 13 themselves and the frictional thermal energy.

In the above embodiment, a truncated conical leaf spring 13 is used, but instead of this, a beam-shaped spring 15 as shown in FIG. 5 may be used.

That is, this beam cedar leaf spring 15 has a plurality of leg walls that are inclined so as to spread out in a V-shape, in this modified example, two pairs of leg wall parts 15a. The spring means 12 is constructed by preparing a plurality of springs 15 and stacking their respective leg wall portions 15a on top of each other.

[Effects] As is clear from the above description of the embodiments, according to the present invention, the movable core is moved against the passive core by the frictional force caused by the deviation between the leg walls of each leaf spring and the elasticity of the leaf spring itself. By mitigating the impact force, it is possible to muffle noise more effectively than with conventional rubber or other elastic damping devices.

In addition, in this invention, the gap between the movable core and the passive core during energization can be made zero compared to the conventional rubber-interposed type, so there is no possibility that the maximum suction force will be reduced, etc. The effect is remarkable.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a solenoid according to the present invention, Fig. 2 is a cross-sectional view of the solenoid, Fig. 3 is a cross-sectional view of a spring means formed by laminating a plurality of plate springs, and Fig. 4 is a single plate spring. FIG. 5 is a perspective view showing a modified example of the leaf spring. In the figure, 1 is a housing, 2 is an outer yoke part, 3 is a front yoke part, 4 is a coil, 7 is a movable iron core, 8 is a passive iron core, 9 is a return coil spring, 12 is a spring means, 13.15 is a leaf spring, and 13a and 15a are leg walls. Patent Applicant: Fujitsu General Co., Ltd. Representative, Patent Attorney: Taku Ohara Figure 1 Figure 2 Figure 3

Claims (4)

[Claims] (1) By arranging a coil in a cylindrical housing that forms a yoke, and inserting a movable iron core into the air core of the coil, and controlling the energization of the coil,
In the solenoid that drives the movable iron core in its axial direction, a passive iron core is disposed in the air core portion of the coil so as to face the rear end of the movable iron core, and the passive iron core has substantially the same inclination. The housing is supported by the housing via a spring means formed by stacking plate springs having corner-shaped leg walls with the leg walls closely joined to each other, and the movable core receives an impact against the passive core. A solenoid characterized in that the force is attenuated by the elasticity of the leaf spring and the frictional force generated between the leg walls. (2) In claim (1), the leaf spring is
A solenoid characterized in that the leg wall portion has a truncated conical shape that spreads out like a trumpet. (3) In claim (1), the leaf spring is
A solenoid characterized in that it is a beam-shaped spring having a plurality of leg walls that spread out in a V-shape. (4) The solenoid according to claim (1), wherein the housing is integrally formed with a seat that supports the spring means.