JPH079363Y2 - Solenoid with permanent magnet - Google Patents

Description

[Detailed description of the device] [The purpose of the device]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid with a permanent magnet used as, for example, a drive source and a control mechanism for operating parts of various devices such as a lock release switch for automobile keys and a coin locker switch. It is a thing. (Prior Art) FIGS. 8 and 9 exemplify a conventional structure of a solenoid with a permanent magnet of this type. The solenoid 51 with a permanent magnet shown in FIGS. 8 and 9 is a plunger. A cylindrical solenoid coil 52 having a moving portion 52a at the center,
The yoke 53 has a yoke 53 through which a magnetic flux passes, and the yoke 53 has a plunger contact portion 53a that partially projects into a plunger moving portion 52a provided in the solenoid coil 52. Further, the solenoid coil is provided on the inner surface side of the yoke 53.
The permanent magnet 54 has a plunger moving part 54e coaxial with the plunger moving part 52a of 52, and the permanent magnet 54 is composed of four rod-shaped magnets 54a, 54b, 54c, 54d. Each has an N pole inside and an S outside
It is provided in the direction of the pole. Further, a cylindrical plunger guide 55 is provided inside the plunger moving portion 52a of the solenoid coil 52 and the plunger moving portion 54e of the permanent magnet 54, and a plunger 56 is provided in the plunger guide 55. A coil spring 57 is provided between the flange portion 56a provided on the plunger 56 and the tip end portion of the plunger guide 55. In the solenoid 51 with permanent magnet having such a structure, when the solenoid coil 52 is energized, the plunger 56
Is moved in the backward direction (upward direction in FIG. 8) by the magnetic force generated by energizing the solenoid coil 52, and is held in a floating state by the coil spring 57. In this state, when the end of the plunger 56 is brought into contact with the plunger contact portion 53a by manually pushing the plunger 56 and moving it in the forward direction (downward in FIG. 8), the permanent magnet 54 (54a ~ 54d), the magnetic flux passing through the plunger 56 and the yoke 53 is formed in the direction of the arrow, and the plunger 56
Is self-held in that position. Next, when the solenoid coil 52 is energized again, the plunger 56 moves in the backward direction (upward direction in FIG. 8) against the self-holding action of the permanent magnet 54, and the coil spring
It is held in a floating state by 57. Therefore, such movement of the plunger 56 can be used as a drive source or a control mechanism for operating parts of various devices. (Problems to be solved by the invention) However, such a conventional solenoid with a permanent magnet is used.
In the 51, since the four bar-shaped magnets 54a to 54d are used as the permanent magnets 54, the work for assembling the four bar-shaped magnets 54a to 54d in the yoke 53 in the same pole direction is difficult. There is also a problem that the amount of magnetic flux may decrease or fluctuate when a gap is created between the bar-shaped magnets 54a to 54d, and it has been a problem to solve such a problem. (Purpose of the Invention) The present invention has been made in view of such a conventional problem, and it is extremely easy to assemble a permanent magnet, and it is difficult for a decrease or variation in the amount of magnetic flux to occur. It is possible to increase the amount of magnetic flux by utilizing almost all of the above, and to further improve the attraction force for the plunger to further improve the operation reliability and stability. It is therefore an object of the present invention to provide a solenoid with a permanent magnet that can reduce the size and weight of the entire solenoid by reducing the size of the permanent magnet.

[Constitution of device]

(Means for Solving the Problem) A solenoid with a permanent magnet according to the present invention has a solenoid coil having a plunger moving part, a yoke through which magnetic flux passes, and a plunger moving hole coaxial with the plunger moving part of the solenoid coil. And an integral rare earth-iron-based permanent magnet that is magnetized in the radial direction around the plunger moving hole, and moves in the plunger moving portion and the plunger moving hole and contacts the yoke on the moving side in the forward direction. The invention relates to the solenoid with a permanent magnet described above, which is characterized in that it is provided with a contacting plunger and an elastic body that is compressed by the plunger moving in the forward direction and urges in the direction to move the plunger in the backward direction. The above-mentioned configuration is used as a means for solving the problems in the past. (Operation of the Invention) Since the solenoid with a permanent magnet according to the present invention has the above-described structure, it is possible to use an integral permanent magnet as compared with the conventional case in which the permanent magnets divided into four rod-shaped magnets are assembled. Since it is only required to assemble, the workability of assembling is remarkably improved.This permanent magnet is made of a rare earth-iron system, particularly preferably plastic, and is magnetized in the radial direction around the plunger moving hole. Therefore, the amount of magnetic flux is increased more than before, the attraction force for the plunger is increased, and the operation reliability and stability are improved. The volume of the solenoid may be reduced, and the solenoid is reduced in size and weight. (Embodiment) FIGS. 1 to 3 show an embodiment of a solenoid with a permanent magnet according to the present invention. FIGS. 1 and 2 show the structure, and FIG. 3 shows the operation. There is. A solenoid 1 with a permanent magnet having the structure shown in FIGS. 1 and 2 has a cylindrical solenoid coil 2 having a plunger moving portion 2a as a center and a yoke 3 having a U-shaped cross section through which magnetic flux passes.
The yoke 3 has a plunger contact portion 3a that partially projects into the plunger moving portion 2a provided on the solenoid coil 2. Further, on the inner surface side of the yoke 3, there is a plunger moving hole 4a coaxial with the plunger moving portion 2a of the solenoid coil 2, and particularly as is clear from FIG. 2, centering around the plunger moving hole 4a. It has an integral rare earth-iron-based permanent magnet 4 which is magnetized in the radial direction. This permanent magnet 4 is, for example, Nd-B-Co-Fe based plastic magnet, Nd-
It consists of Fe-B system plastic magnets and Nd-B-Co-Dy system plastic magnets. Further, the plunger moving part 2a of the solenoid coil 2
Further, a cylindrical non-magnetic plunger guide 5 is provided inside the plunger moving hole 4a of the permanent magnet 4, and a plunger 6 is disposed in the plunger guide 5. Collar 6a provided at the top
A coil spring 7, which is an elastic body, is provided between the end of the plunger guide 5 and the plunger guide 5, and a cover 8 is provided above the permanent magnet 4. In the solenoid 1 with a permanent magnet having such a structure, when the solenoid coil 2 is energized, the plunger 6
Is moved in the backward direction (upward in FIG. 1) by the magnetic force generated by energizing the solenoid coil 2, and is held in a floating state by the coil spring 7 which is an elastic body. In this state, when the end of the plunger 6 is brought into contact with the plunger abutting portion 3a by pushing the plunger 6 manually and moving it in the forward direction (downward in FIG. 1), as shown in FIG. Then, a magnetic flux passing through the permanent magnet 4, the plunger 6 and the yoke 3 is formed in the direction of the arrow, and the plunger 6 is held by itself at that position. Next, when the solenoid coil 2 is energized again, the plunger 6 moves in the backward direction (upward direction in FIG. 1) against the self-holding action of the permanent magnet 4, and the coil spring 7 which is an elastic body. Is held in a floating state. Therefore, such movement of the plunger 6 can be utilized as a drive source or a control mechanism for operating parts of various devices, and the position of the plunger 6 is self-held by the permanent magnet 4 and the coil spring 7. It consumes no electric power except when operating. FIG. 4 shows another structural example of the solenoid with permanent magnet 1 according to the present invention. The cover 8 provided in the solenoid with permanent magnet 1 shown in FIG. The plunger guide 5 is integrated with plastic, and the plunger guide 5a and the cover
5b and 5b are shown. FIG. 5 shows still another structural example of the solenoid 1 with a permanent magnet according to the present invention. In this embodiment, the plunger guide 5, the plunger guide portion 5a and the cover portion are provided.
5B, a permanent magnet guide portion 5c, and a solenoid coil guide portion 5d are shown. FIG. 6 shows a structural example of the permanent magnet 4 constituting the solenoid 1 with a permanent magnet according to the present invention. The permanent magnet 4 of FIG. 6 (a) has a rectangular outer shape and a plunger moving hole 4a. Is a perfect circle, the outer shape of the permanent magnet 4 of FIG. 6 (b) is rectangular and the plunger moving hole 4a is a regular hexagon, and the outer shape of the permanent magnet 4 of FIG. 6 (c) is rectangular. The plunger moving hole 4a has a regular octagonal shape, and is shown in FIG. 6 (d).
In the case of the permanent magnet 4, the outer shape is a perfect circle and the plunger moving hole 4a is also a perfect circle. Further, the shape of the permanent magnet 4 is not limited to those exemplified above, and may be suitably adopted according to the specifications and the like. FIG. 7 shows a mounting mode of the permanent magnet 4,
In the solenoid 1 with a permanent magnet shown in FIG. 1, the case where the permanent magnet 4 is fixed to the inner surface of the yoke 3 is shown.
It may be fixed to one surface of the cover 8 with an adhesive or the like as shown in FIG. 7A, and the outer peripheral edge of the cover 8 surrounds the upper outer periphery of the yoke 3 as shown in FIG. 7B. The shape may be provided with a hole 8a for passing a mounting screw or the like, and an appropriate permanent magnet mounting mode can be adopted according to the specifications and the like.

[Effect of device]

Since the solenoid with a permanent magnet according to the present invention has the above-described structure, it is possible to assemble an integral permanent magnet as compared with the conventional case in which a permanent magnet divided into four rod magnets is assembled. Therefore, it is possible to remarkably improve the assembling workability, and since this permanent magnet is an integral magnetized in the radial direction around the plunger moving hole, the amount of magnetic flux is greater than before. By increasing the suction force to the plunger, it is possible to further improve the reliability and stability in the operation of the plunger. It is possible to reduce the volume of the magnet and reduce the size and weight of the solenoid when the attraction force against the magnet is reduced to the conventional level. Leads to significantly better effects such is possible.

[Brief description of drawings]

1, 2, and 3 are longitudinal sectional explanatory views, horizontal sectional explanatory views, and longitudinal sectional explanatory views of the operation, showing an embodiment of a solenoid with a permanent magnet according to the present invention, respectively. FIG. 5 is a longitudinal sectional view showing another embodiment of the solenoid with magnet according to the present invention, and FIGS. 6 (a) and 6 (b).
FIGS. 7 (c) and 7 (d) are perspective views showing examples of the shape of the permanent magnet, FIGS. 7 (a) and 7 (b) are vertical cross-sectional views illustrating the attachment mode of the permanent magnet, FIGS. It is the vertical cross-section explanatory drawing and horizontal cross-section explanatory drawing of the conventional solenoid with a permanent magnet, respectively. 1 ... Solenoid with permanent magnet, 2 ... Solenoid coil, 2a ... Plunger moving part, 3 ... Yoke, 3a ... Plunger contact part, 4 ... Permanent magnet, 4a ... Plunger moving hole, 6 ... Plunger, 7 ... Coil spring (elastic body).

Claims (1)

[Scope of utility model registration request] 1. A solenoid coil having a plunger moving portion, a yoke through which a magnetic flux passes, and a plunger moving hole coaxial with the plunger moving portion of the solenoid coil, and attached in a radial direction around the plunger moving hole. A magnetized integral rare earth-iron-based permanent magnet, a plunger that moves in the plunger moving portion and the plunger moving hole and that abuts the yoke on the moving side in the forward direction, and is compressed by the plunger moving in the forward direction, and A solenoid with a permanent magnet, comprising an elastic body for urging the plunger in a backward direction.