JPH07263222A - Self-holding solenoid - Google Patents

Abstract

PURPOSE:To sustain the attracted state even when a solenoid is not conducted by mounting a permanent magnet on the inner surface of the flange of a fixed core. CONSTITUTION:A circular or tubular push-pull solenoid is fixed, on the inner surface of the flange of a base 2, with a doughnut type permanent magnet 12. An intermediate pole 13 is press fitted in a case 1 while sandwiching the permanent magnet 12 and the base 2. The base 2 is press fitted in the holder 11 which is then press fitted in the intermediate pole 13. Attraction takes place upon excitation, and a magnetic circuit is established by the built-in permanent magnet 12 upon interruption of power supply thus sustaining the attracted state. Since the holding power is not required, the coil is not heated at the time of holding. Consequently, energy is saved and a small sized solenoid can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a round or cylindrical self-holding push-pull solenoid.

[0002]

2. Description of the Related Art FIG. 1 shows an example of a conventional round push-pull solenoid structure. In the figure, 1 is a magnetic material case,
2 is a magnetic base (fixed iron core), 3 is a non-magnetic bearing, 4 is a coil bobbin, 5 is a coil, 6 is a magnetic plunger (movable iron core), and 7 is a non-fixed body fixed to the plunger. A magnetic shaft, 8 is a non-magnetic residual magnetism prevention plate, 9 is a return spring, and 10 is a lead wire.

In this operation, when the coil 5 is energized and excited, the plunger 6 is pulled toward the base 2 to perform a suction operation. At this time, the shaft 7 slides in the bearing 3 together with the plunger 6. Return operation is coil 5
When the deenergization is stopped by stopping the energization to, the spring returns to the original position by the force of the return spring 9.

When it is desired to keep the plunger 6 in the attracted state, the coil 5 must be continuously energized. For this reason, the coil heats up, the adsorbing force also weakens accordingly, and the battery life is shortened when the battery is driven. (2)

[0005]

It is an object of the present invention to provide a push-pull solenoid having a round shape or a cylindrical shape, which is capable of holding an attracting state even when no electricity is applied by putting a permanent magnet on the base flange surface. With the goal.

[0006]

FIG. 2 is a structural view showing an embodiment of the present invention, in which the same reference numerals as those in the conventional example indicate equivalent parts. A donut-shaped permanent magnet 1 having a hole in the center of the inner flange surface of the base 2.
Install 2. The intermediate magnetic pole 13 is the base 2 of the permanent magnet 12.
And press it into case 1 to fix it. The base 2 is press-fitted and fixed to the holder 11, and the holder 11 is press-fitted and fixed to the intermediate magnetic pole 13.

With this structure, when excited, the magnet operates from the demagnetized state of FIG. 3 (a) as shown in FIG. 3 (b). Since the magnetic circuit shown by the arrow in (b) is formed, the magnetic element is held in the attracted state.

When returning, the positive and negative polarities of the lead wire 10 of the coil 5 are reversed to demagnetize the magnetic force of the permanent magnet, and the demagnetizing position by the force of the return spring 9 shown in FIG.
Return as shown in (a).

Many types of open-frame type self-holding solenoids are known, but the polarities of the permanent magnets are arranged in the direction outward from the center of the solenoid. Therefore, there is a drawback that the solenoid itself becomes large. In the structure of the present invention, the permanent magnet can be formed into a donut shape so as to be inserted into the base of the magnetic body, and the solenoid can be miniaturized. (3)

[0010]

[Explanation of effect] Since it is attracted by pulse input and attracted and held by the permanent magnet, holding power is not required and coil heat is not generated during holding. Therefore, the energy saving effect can be achieved and the solenoid can be downsized. Further, the holding state can be maintained without any influence even during a power failure in the adsorption state.

[Brief description of drawings]

FIG. 1 is a structural diagram of a conventional round push-pull solenoid.

FIG. 2 is a structural diagram of a self-holding push-pull solenoid of the present invention.

3 (a) and 3 (b) are operation and holding state diagrams of the self-holding push-pull solenoid of the present invention.

[Explanation of symbols]

 1 case 2 base 3 bearing 4 coil bobbin 5 coil 6 plunger 7 shaft 8 remanent magnetism prevention plate 9 return spring 10 lead wire 11 holder 12 permanent magnet 13 intermediate magnetic pole (4) 14 sleeve 15 stopper

Claims (1)

[Claims] 1. A round-shaped or cylindrical push-pull solenoid comprising a coil and a case of a magnetic material surrounding the entire circumference of the coil and a movable iron core of a magnetic material to which a fixed iron core and an output shaft are fixed. A self-holding solenoid characterized in that a permanent magnet is mounted on the inner flange surface of the fixed iron core.