JPH02172206A - Solenoid - Google Patents

Abstract

PURPOSE:To suppress an impact noise created at the time of operation by a method wherein an adjustment shaft for adjusting the spring load of a restoration spring is provided inside a fixed core so as to move freely. CONSTITUTION:An adjustment shaft 9 which is moved along the axial direction of a fixed core 4 is provided inside the fixed core 4. Screws are formed on the circumferential surface of the adjustment shaft 9 and on the inner surface of the insertion hole 10 of the fixed core 4 and the adjustment shaft 9 is screwed into the insertion hole 10. By adjusting the adjustment shaft 9 to adjust the length of a restoration spring 7, if the spring constant is properly selected, the variation of the free length and spring load of the restoration spring 7 can be suppressed and a constant restoration force can be obtained. With this constitution, stable sealing performance can be obtained when the solenoid is applied to a solenoid value and an impact noise created when a movable core collides with the fixed core 4 can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a solenoid used in an electromagnetic valve.

[Prior Art 1] A solenoid used in a conventional electromagnetic valve is shown in FIG. This solenoid is used in a monostable electromagnetic valve, and includes a yoke 1, which has a cylindrical shape with a closed side, and has a permanent magnet 2 fixed to the inner surface of the open side, which applies an attractive force when the magnet is not moving.
A stopper 8 made of a non-magnetic material is attached to the open surface of the yoke 1, a fixed core 4 is fixed to the stopper 8, and a coil 3 is installed along the inner surface of the yoke 1 on the closed surface side. When this coil 3 is energized, it is attracted to the fixed iron core 4 and the yoke 1
rA wood face? A movable core 5 whose tip protrudes freely forward and backward through the inserted insertion hole 16 is inserted between the fixed core 4 and the movable core 5, and urges the movable core 5 in the direction of protruding from the insertion hole 16 when not energized. It is composed of a return spring 7. Note that a valve rubber 6 is attached to the tip end surface of the movable iron core 5.

In this solenoid, when the coil 3 is energized, the movable iron core 5 is attracted to the fixed iron core 4, and when the coil 3 is de-energized, the return force of the return spring 7 moves the movable iron core 5 to the yoke 1.
protrude from

[Am to be solved by the invention] However, in the solenoid shown in FIG.
Since the stroke is very small, it is used where the slope of the attraction force curve, including non-excited attraction force, is very steep. Therefore, the spring constant of the return spring 7, which is the load, is also very strict II! For example, if there is a slight variation in dimensions, the return force will vary and the sealing performance will become unstable. Note that if the spring constant of the return spring 7 is too high, the return spring will be difficult to manufacture and expensive.

Furthermore, in this type of solenoid, the movable core 5 collides with the fixed core 4 during operation, producing a collision sound. For this reason, it cannot be used for applications in which this collision noise is a problem, and there is also the problem that the impact vibration accompanying this collision causes a reduction in the lifespan of peripheral parts.

Therefore, as shown in figure tjS7, fixed core 4 and rIT!
! The opening of the iron core 5 or the opening of the movable iron core 5 as shown in FIG.
A cushioning material 11 is provided between the fixed iron core 4 and the movable iron core 5 to prevent collision between the fixed iron core 4 and the movable iron core 5, thereby eliminating the collision sound.

However, when the cushioning material 11 is used as shown in FIGS. 7 and 8, a gigantic force is generated between the fixed core 4 and the movable core 5, which causes the problem that the attraction force during non-excitation becomes extremely small. Ta.

Note that a bistable solenoid shown in FIG. 9 may also be used as the electromagnetic valve. This solenoid is constructed by punching through holes 16 in both end faces of a yoke 1 whose both sides are closed, and fixing a fixed iron core 4 into each through hole 16. The movable iron core 5 is housed in the yoke 1, and has a structure in which an output shaft 14 protruding from both ends can freely move through a through hole 17 bored in the fixed iron core 5. However, in this solenoid as well, the movable core 5 moves in the left-right direction depending on the direction of the current flowing through the coil 3, and the movable core 5 collides with the fixed core 4, so a collision noise is generated as in the monostable type. Occur.

The specific invention has been made in view of the above points, and its purpose is to provide a solenoid with a constant return force and stable sealing performance.

Another object of the related invention is to provide a solenoid that produces less collision noise during operation without changing the force applied when not energized.

[Means for Solving the Problems 1] In order to achieve the above object, the present invention includes an adjustment shaft that is movably housed within a fixed iron core and adjusts the spring load of a return spring.

Further, in the related invention, in order to achieve the above object, a buffer material fixed to the stopper is provided. In the case of a bistable solenoid, there are two permanent magnets fixed to each end with their polarities facing the same direction, a yoke, a magnetic pole piece fixed to both ends of the permanent magnet, and a coil. A movable iron core that moves within the yoke depending on the direction of the current flowing through the yoke may be used.

[Function 1] In the specific invention, the spring load of the return spring can be adjusted using the adjustment shaft, so that the suction force can be kept constant even if there are variations in the free length and spring load.

Further, in the related invention, impact noise is reduced by absorbing the impact when the movable core collides with the fixed core using a cushioning material. Furthermore, in the case of a bistable solenoid, the structure eliminates the fixed core, which is the member with which the movable core collides, to eliminate collision noise.

[Example 1J FIG. 1 shows an example of the specific invention. In this embodiment, an adjustment shaft 9 that moves in the axial direction of the fixed iron core 4 is provided within the fixed iron core 4. Note that the other structures are the same as the solenoid shown in FIG. Also, one method for moving the adjustment shaft 9 in the axial direction of the fixed core 4 is to cut a thread on the curve of the adjustment shaft 9 and the inner surface of the insertion hole 10 of the fixed core 4, and insert the adjustment shaft 9 into the insertion hole 10. Just screw it in.

Figure 2 is a diagram showing the suction force curve, where A is the rated suction force, the opening is the suction force when not energized, and × is the stroke variation. In order to obtain the return force of the return spring 7 (indicated by 2 in the figure), it is necessary to suppress variations in the free length and spring load of the return spring 7 as shown in the shaded area. Therefore, in the solenoid shown in FIG. 6 which is not equipped with a means for adjusting the return spring 7, the return force varies and the sealing performance of the electromagnetic valve becomes unstable. However, in this embodiment, since the above-mentioned adjustment shaft 9 is provided, by adjusting the adjustment shaft 9 and adjusting the length of the return spring 7, if the spring is already set, as shown in FIG. Variations in the free length and spring load of the return spring 7 can be suppressed within the shaded area C, and the return force can be kept constant. Therefore, the sealing performance of the electromagnetic valve is stabilized. In addition, in manufacturing the return spring 7, the spring load can be made rough, so the return spring
7 can be manufactured at low cost. Further, by adjusting the adjustment shaft 9, it is possible to absorb variations in the non-excitation attraction force due to variations in the magnetic circuits of the permanent magnets 2 and their ponds. Note that the fixed core 4 and the stopper 8 are screwed together, so that the fixed core 4 and the stopper 8 are screwed together.
If it is made movable in the axial direction, the variation in stroke can be adjusted in the same way.

E Example 21 FIG. 3 shows an example of the related invention. In this embodiment, a recess 13 is formed inside the center part of the stopper 8, and this recess 1
A cushioning material 12 is housed within 3. Note that the fixed core 4 and the stopper 8 are not fixed, and the stopper 811111 of the fixed core 4 is formed to have a large diameter, so that the difference between the stepped M portion and the inner diameter of the coil 3, which occurs on the surface of the fixed core 4, and the buffer The fixed core 4 is positioned in the longitudinal direction by the initial deflection of the material 12.

In this embodiment, when the movable core 5 is attracted and collides with the fixed core 4, the shock absorbing material 12 acts as a shock absorber, and the collision sound affects surrounding parts (such as resonance). Since the collision is not given, the collision ￥f becomes smaller. Moreover, since the impact vibration does not reach the surrounding parts, the lifespan of the surrounding parts will not be shortened.

Furthermore, since the magnetic circuit is the same as the conventional solenoid and no gap occurs between the fixed iron core 4 and the movable iron core, the attractive force characteristics and the attractive force when not energized are also the same.

[Embodiment 31 FIG. 4 shows another embodiment of the related invention. In this embodiment, the collision sound of the bistable solenoid is suppressed. In this embodiment, permanent magnets 23 are installed at both ends of the cylindrical yoke 1.
2 □ are arranged in the illustrated polarity, and magnetic pole pieces 15 are provided at both ends of the permanent magnets 23 and 2 □. In addition, flanges are formed at both ends of the movable iron core 5 to prevent removal.

FIG. 5 shows a state in which the movable core 5 of this solenoid is stabilized on the left side. At this time, the magnetic fluxes generated by the permanent magnets 21 and 22 are a main magnetic flux φa shown by a in the figure, and leakage magnetic fluxes φb and φb shown by s and c in the figure, and the main magnetic flux φa is the leakage magnetic flux φ1], Since it is much larger than φb°, it is stable in the left position. In this state, the movable core 5 is attached to the coil 3 as shown in Fig. 5 (
When a current is applied with the polarity shown in I)), an attractive force and a repulsive force are generated between the movable core 5 and the magnetic pole piece 15, respectively, as indicated by the arrows, and the movable core 5 moves to the right. Then, after the movable iron core 5 moves to the right as shown in FIG. 5(c), when the current in the coil 3 is cut off, as shown in FIG. 5(a).
Stabilize on the right side in the same way as in the case of . In this embodiment, since the fixed core 4 is not provided as described above, there is no member that collides with the movable core 4 during operation, and no collision noise is generated. Moreover, since there is no impact vibration, there is no need to worry about shortening the lifespan of peripheral parts.

[Effects of the Invention 1] As described above, the present invention is equipped with an adjustment shaft that is movably housed within the fixed iron core and adjusts the spring load of the return spring. The suction force can be kept constant by absorbing the spring load by moving the adjustment shaft, and therefore the sealing performance can be stabilized when used as an electromagnetic valve. Furthermore, since the spring load can be made rough in manufacturing the return spring, there is an advantage that the return spring can be manufactured at low cost.

Further, in the related invention, since the shock absorber 41 is fixed to the stopper, the impact noise can be reduced by absorbing the shock when the movable core collides with the fixed core using the shock absorber. Furthermore, in the case of a bistable solenoid, two permanent magnets are connected to a yoke fixed to both ends with their polarities oriented in the same direction, magnetic pole pieces fixed to both ends of the permanent magnet, and a coil. By comprising a movable iron core that moves within the yoke according to the direction of the flowing current, the structure 1 eliminates the fixed iron core, which is the member that the movable iron core collides with, and can eliminate collision noise.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the specified invention, Fig. 2 is a characteristic diagram for explaining the same adjustment method, Fig. 3 is a sectional view of an embodiment of the related invention, and Fig. 4 is a related invention. 5(a) to 9(c) are explanatory views of the same operation as above, FIG. 6 is a sectional view of a conventional example according to the specific invention, and FIGS. 7 to 9
Each figure is a sectional view of a conventional example of the related invention. 1 is a yoke, 2, 2. ．． 22 is a permanent magnet, 3 is a coil, 4
5 is a fixed iron core, 5 is a movable iron core, 7 is a return spring, 8 is a stopper, 9 is an adjustment shaft, 12 is a buffer material, and 15 is a magnetic pole piece. Agent Patent Attorney Stone 1) Ai 7th 3rd Figure 4th Figure 6th Figure 7th! l! Figure 5 Figure 8 Figure 9

Claims (3)

[Claims] (1) A yoke to which a permanent magnet is attached that provides an attractive force when not energized, a fixed core fixed to the yoke, a movable core that is attracted to the fixed core by energizing the coil, and a fixed core. A solenoid comprising: a return spring interposed between the fixed core and the movable core to return the movable core when not energized; and an adjustment shaft movably housed within the fixed core to adjust the spring load of the return spring. (2) A yoke to which a permanent magnet is attached that applies an attractive force when not energized, and a stopper made of a non-magnetic material fixed to the yoke;
A coil wound along the inner surface of the yoke, a buffer material fixed to the stopper, a fixed core placed between the buffer material and the coil, and when the coil is energized, it is attracted to the fixed core. A solenoid with a movable iron core. (3) A yoke with two permanent magnets fixed to both ends with their polarities oriented in the same direction, magnetic pole pieces fixed to both ends of this permanent magnet, and a yoke that is connected to the yoke according to the direction of the current flowing through the coil. A solenoid consisting of a movable iron core that moves the