JP2016051708A - Built-in permanent magnet type solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a built-in permanent magnet type solenoid that can suppress increase of the amount of magnetic flux passing through a suction part and surely reduce the suction force even when the magnetic flux occurring in a coil is larger with respect to the magnetic flux of a magnet.SOLUTION: A disc-shaped permanent magnet 13 which is in close contact with a side wall surface 11a is provided inside a body 11, the permanent magnet 13 is formed to be concentric to the inner diameter of the body 11, and the outer diameter has a gap for the inner diameter. A disc-shaped stopper 14 is in contact with the lower surface of the permanent magnet 13, and the outer diameter of the stopper 14 has an air gap 15 for the inner diameter of the body 11. A coil bobbin 16 is inserted and fitted in the inner diameter of the body 11, and a guide 17 is inserted and fitted to the coil bobbin 16. A plunger 19 is inserted and fitted in the inner diameter of the coil bobbin 16, and displaced by electromagnetic force of magnetization of the coil bobbin 16.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solenoid, and more particularly to a permanent magnet built-in type solenoid provided with a permanent magnet.

Conventionally, this type of solenoid generates an attractive force by the attractive force of a permanent magnet when the coil is not energized, and the magnetic flux passes through the attractive part.
When the coil is energized, the magnetic flux generated by the coil flows to cancel the magnetic flux of the magnet, the magnetic flux of the magnet passes through the magnetic path of another part, and the magnetic flux of the magnet that passes through the attracting part decreases. The suction force can be released (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 60-1814

However, in Patent Document 1, when energization of the coil starts, the magnetic flux generated by the coil flows so as to oppose the magnetic flux of the magnet, the amount of magnetic flux of the magnet passing through the attracting portion decreases, and the attractive force decreases. If the coil generates an amount of magnetic flux that just cancels out the magnetic flux of the magnet, the magnetic flux that passes through the attracting portion disappears, so the attractive force becomes almost zero.
However, when the magnetic flux generated by the coil is sufficiently large relative to the magnetic flux of the magnet, the magnetic flux passing through the attracting portion is switched from that of the magnet to that of the coil, and there is a disadvantage that it begins to generate an attractive force again.
The present invention has been made in order to solve the problem, and the main first magnetic path through which the magnetic flux of the magnet passes when not energized, the second magnetic path through which the magnetic flux of the coil passes, and the coil receives the magnetic flux. Three magnetic paths of the sub third magnetic path with a minute air gap that switches the magnetic flux of the magnet when it is generated are formed, and the attracting portion is provided at the edge cut from the second and third magnetic paths. Therefore, even when the magnetic flux generated by the coil is larger than the magnetic flux of the magnet, an object is to obtain a solenoid with a built-in permanent magnet that can suppress the increase in the amount of magnetic flux passing through the attracting portion and reliably reduce the attractive force. And

The invention for solving the above-mentioned problems is
In a solenoid comprising an electromagnetic coil, a substantially symmetrical fixed iron core outside the electromagnetic coil, and a movable iron core provided inside the fixed iron core,
The fixed iron core is mounted on the inside of the body and coaxially with the inner diameter of the body, the outer peripheral surface forms a gap with respect to the inner diameter of the body, and the side wall surface is on the side surface of the body. Permanent magnets provided to engage with each other, side surfaces are in close contact with the permanent magnets, are formed coaxially with the inner diameter of the body, and are provided with an outer diameter forming an air gap with respect to the inner diameter of the body. Formed with a stopper,
The movable iron core is formed by a plunger slidably inserted into the guide member, and a pin attached to the plunger,
An electromagnetic coil disposed on an inner peripheral surface of the body with a gap in an axial direction with respect to the stopper;
A guide member having a flange engaged with an end surface of the electromagnetic coil and an outer peripheral surface fitted into the inner peripheral surface of the electromagnetic coil;
A spring member loosely inserted into the concave portion of the plunger and having both ends supported by the plunger and a side wall surface of the stopper or cover;
The body is characterized in that the fixed iron core and the electromagnetic coil are integrally formed in the body by caulking a yoke engaged with an end face of the electromagnetic coil.

  According to the present invention, the main first magnetic path through which the magnetic flux of the magnet passes when not energized, the second magnetic path through which the magnetic flux of the coil existing in the middle of the main first magnetic path, and the coil Forming a sub third magnetic path having a minute air gap in which the magnetic flux of the magnet is switched when the magnetic flux is generated, and providing the adsorbing portion at a position cut off from the second and third magnetic paths. Even when the magnetic flux generated is larger than the magnetic flux of the magnet, an increase in the amount of magnetic flux passing through the attracting portion can be suppressed and the attractive force can be reliably reduced.

1 is a schematic longitudinal sectional view showing a schematic structure of a permanent magnet built-in solenoid according to an embodiment of the present invention. It is operation | movement explanatory drawing of the permanent magnet built-in type solenoid of FIG. It is explanatory drawing of the flow of the main magnetic path in FIG. It is explanatory drawing of the flow of the magnetic path of a coil in FIG. 1, and a sub magnetic path. It is a general | schematic longitudinal cross-section which shows schematic structure of the permanent magnet built-in type solenoid which concerns on other embodiment.

Hereinafter, preferred embodiments of a permanent magnet built-in solenoid according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic longitudinal sectional view showing a schematic structure of a solenoid 10 with a built-in permanent magnet (hereinafter referred to as a solenoid 10). In FIG. 1, reference numeral 11 denotes a disk-shaped body. A side wall surface 11a is formed at one end (upper end in FIG. 1), and a circular opening 12 is formed at the center of the side wall surface 11a. Yes.
A cylindrical permanent magnet 13 that is in close contact with the side wall surface 11 a is provided inside the body 11, the permanent magnet 13 is formed to be concentric with the inner diameter of the body 11, and the outer diameter is the body 11. A gap is formed with respect to the inner diameter of the. The permanent magnet 13 has a circular opening 13a at the center. A non-magnetic material may be filled in the gap between the inner diameter of the body 11 and the outer diameter of the permanent magnet 13.

A disk-like stopper 14 is attached to the lower surface of the permanent magnet 13, and the outer diameter of the stopper 14 is formed with an air gap 15 with respect to the inner diameter of the body 11.
The air gap 15 is set to be larger than the gap between the suction portion 19 a between the stopper 14 and the plunger 19 and the gap in the sliding direction between the guide 17 and the plunger 19.
A cylindrical coil bobbin (electromagnetic coil) 16 is inserted into the inner diameter of the body 11, and a cylindrical guide 17 having a flange portion 17 a is inserted into the inner diameter of the coil bobbin 16. The coil ribbon 16 is engaged with the side wall surface (the upper surface in FIG. 1).

  The upper surface of the flange portion 17 a is seated on a stepped portion 11 b formed on the inner diameter of the body 11 such that a space 18 is formed in the axial direction with respect to the lower surface of the stopper 14. The coil bobbin 16 is seated on the stepped portion 11b of the body 11 and formed so as to maintain a gap 18 between the lower surface of the stopper 14 and the upper surface of the coil bobbin 16, but a non-magnetic substance is provided in the gap 18. The stepped portion 11b of the body 11 may be eliminated.

  A plunger 19 is slidably inserted in the inner diameter of the guide 17 and is displaced by the electromagnetic force of excitation of the coil bobbin 16. A spring member 21 is mounted on the upper surface of the plunger 19 in a recess 20 oriented in the axial direction. One end (lower end in FIG. 1) of the spring member 21 is engaged with the recess 20 and the other end (in FIG. 1). The upper end is engaged with the lower surface of the stopper 14. Reference numeral 22 indicates a pin fixed to the plunger 19, and is loosely inserted into the spring member 21.

  A disc ring 23 is attached to the lower end of the coil bobbin 16. The inner diameter of the ring 23 is fitted into the outer diameter of the guide 17, and the body 11 together with the ring 23 and the plate engaged with the ring 23. It is crimped on. As a result, the coil bobbin 16 and the guide 17 are pressed against the stepped portion 11a of the body 11 and fixed.

The solenoid 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described.
In FIG. 1, the plunger 19 moves forward (upward in FIG. 1) to the coil bobbin 16 by electromagnetic force or external force, contacts the stopper 14, and maintains the attracted state by the magnetic force of the permanent magnet 13. In this state, no energization or external force is applied during adsorption.
At this time, the magnetic flux flow of the magnet generated in the solenoid 10 is formed as a magnetic path 26 shown in FIG.

In order to release the contact between the stopper 14 and the plunger 19, when the coil bobbin 16 is excited so as to have a magnetic flux opposite to the magnetic flux of the permanent magnet 13, the second in the middle of the main first magnetic path 25. The magnetic flux of the coil flows through the magnetic path 26. Since the second magnetic path 26 is located in the middle of the first magnetic path 25, when the magnetic flux of the coil circulates in the second magnetic path 26 by excitation of the coil, the magnetic resistance of the first magnetic path 25 increases. .
Then, the magnetic flux of the magnet starts to pass through the third magnetic path 27 having a minute air gap from the first magnetic path 25 having a high magnetic resistance. As a result, the magnetic flux passing through the adsorbing portion 19a is reduced, the attractive force is reduced, and the attractive force is reduced. Therefore, the plunger 19 is retracted (lowered in FIG. 2) by the elastic force of the spring member 21, and the state shown in FIG. Become.

  Even if the excitation of the coil is stopped at the position where the plunger 19 of FIG. 2 is retracted, the gap between the stopper 14 and the plunger 19 caused by the retracting of the plunger 19 is on the main first magnetic path 25. Since this gap is larger than the air gap of the third magnetic path 27, the magnetic flux of the permanent magnet 13 still passes through the third magnetic path 27, and since the attractive force is weak, the plunger 19 is moved by the elastic force of the spring member 21. Holds in the retracted position.

FIG. 5 is a schematic longitudinal sectional view showing a schematic structure of a permanent magnet built-in solenoid 30 according to another embodiment. In FIG. 5, the same components as those of FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
In FIG. 5, the recess 31 formed in the plunger 19 is formed on the lower surface of the plunger 19. Therefore, both ends of the spring member 21 fitted into the recess 31 are supported by the plate 24 and the bottom surface of the recess 31.
For this reason, the permanent magnet built-in solenoid 30 is normally held (fixed with a magnet), with the coil 19 being de-energized, and the position of the exciting spring member 21 is always pressed against the plunger 19. Only when energized, the force of the magnet is canceled out and secured in a movable state.

DESCRIPTION OF SYMBOLS 10 Permanent magnet built-in solenoid 11 Body 12 Opening part 13 Permanent magnet 14 Stopper 15 Air gap 16 Coil bobbin 17 Guide 18 Space | interval 19 Plunger 20 Recessed part 21 Spring member 22 Pin 23 Ring 25, 26, 27 Magnetic path

Claims (1)

In a solenoid comprising an electromagnetic coil, a substantially symmetrical fixed iron core outside the electromagnetic coil, and a movable iron core provided inside the fixed iron core,
The fixed iron core is mounted on the inside of the body and coaxially with the inner diameter of the body, the outer peripheral surface forms a gap with respect to the inner diameter of the body, and the side wall surface is on the side surface of the body. Permanent magnets provided to engage with each other, side surfaces are in close contact with the permanent magnets, are formed coaxially with the inner diameter of the body, and are provided with an outer diameter forming an air gap with respect to the inner diameter of the body. Formed with a stopper,
The movable iron core is formed by a plunger slidably inserted into the guide member, and a pin attached to the plunger,
An electromagnetic coil disposed on an inner peripheral surface of the body with a gap in an axial direction with respect to the stopper;
A guide member having a flange engaged with an end surface of the electromagnetic coil and an outer peripheral surface fitted into the inner peripheral surface of the electromagnetic coil;
A spring member loosely inserted into the concave portion of the plunger and having both ends supported by the plunger and the stopper or the side wall surface of the ring,
A permanent magnet with built-in permanent magnet, wherein the body is integrally formed with the fixed iron core and the electromagnetic coil by caulking a yoke engaged with an end face of the electromagnetic coil.

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