JPH041698Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention biases the movable iron core in one or the other direction in the axial direction by energizing the excitation coil, and
The present invention relates to a self-holding solenoid that maintains a movable core in its biased position even after de-energization.

(Prior Art) Conventional self-holding solenoids are described, for example, in Japanese Patent Publication No. 56-26127 and Japanese Utility Model Publication No. 54-35314. As shown in FIG. 5, this solenoid has a substantially U-shaped yoke made of a magnetic material having an end plate 1a at one end, and a cover plate 2 made of a magnetic material at the other end, and a cover plate 2 made of a non-magnetic material. Both ends of a cylindrical body 3 are fitted through the end plate 1a and the cover plate 2 of the yoke 1, a bobbin 4 is fitted on the outer periphery of the cylindrical body 3, and an excitation coil is attached to the center of the bobbin 4. At the same time, a permanent magnet 6 with a polarity of N pole on the outside and S pole on the inside is attached to both ends of the bobbin 4.
a and 6b are provided. Furthermore, a movable iron core 7 made of a magnetic material is fitted into the inside of the cylinder 3 so as to be slidable in the axial direction.

As shown in FIG. 5, the movable iron core 7, which is moving rightward, is attracted and held by one of the permanent magnets 6a, that is, is in a self-holding state.

On the other hand, in order to move this movable iron core 7 to the left, the excitation coil 5 is energized so that the left end of the movable iron core 7 becomes an S pole and the right end becomes an N pole. At the right end (N pole) of the magnetized movable iron core 7, a repulsive force is generated between it and the outer N pole of the permanent magnet 6a, and an attractive force is generated between it and the inner S pole.
At the left end (S pole) of the movable iron core 7, attraction occurs between it and the outer N pole of the permanent magnet 6a, and a repulsive force occurs between it and the inner S pole, causing the movable iron core 7 to move to the left. . Then, when both ends of the movable iron core 7 face the sides of the poles that receive the attraction action of the permanent magnets 6a and 6b, the leakage magnetic flux decreases and the attraction force increases, causing the moving movable iron core 7 to stop. do.

When the excitation coil 5 is de-energized at the position where the movable core 7 has moved to the left, the movable core 7 becomes attracted to and held by the other permanent magnet 6b, that is, becomes a self-holding state.

In addition, in order to return the movable core 7 from the state in which it has moved to the left to the state shown in FIG. , the movable iron core 7 can be moved to the right and returned to its original position.

(Problem to be solved by the invention) In the conventional solenoid as described above, when both ends of the movable core 7 face the sides of the poles that receive the attraction action of the respective permanent magnets 6a and 6b, the leakage magnetic flux is small. As the suction force increases, the moving movable iron core 7 is stopped, but the movable iron core 7 tends to shift from its stop position due to the magnitude of the inertia of movement; Even if the movable core 7 is a round bar, there is little change in leakage magnetic flux, and since the movable core 7 is held at the shifted position, it is difficult to stop the movable core 7 at a predetermined and accurate position. .

In addition, in a permanent magnet, the end face of the S pole or N pole, that is, the face perpendicular to the lines of magnetic force, has the maximum attraction and repulsion, but in the conventional solenoid described above, the permanent magnet 6
Adsorption and repulsion effects are obtained on the sides of the S and N poles of a and 6b, and the self-holding force of the movable iron core 7 is weak.

The present invention was devised in view of the above-mentioned problems, and aims to provide a solenoid that can hold a movable iron core in an accurate position and has a strong self-holding force due to a permanent magnet.

[Structure of the idea]

(Means for solving the problem) The solenoid of the present invention has two end plates at both ends in the axial direction.
2, 15 are provided inside the solenoid frame 11 made of magnetic material, both ends thereof are provided with both end face plates 12, 15.
A cylindrical body 16 made of a non-magnetic material is fitted through the cylindrical body 16, and a pair of excitation coils 17 are arranged around the outer periphery of the cylindrical body 16.
a, 17b, and a permanent magnet 19 magnetized with different polarities in the radial direction is fitted between the pair of excitation coils 17a, 17b.
A movable iron core 21 is fitted into the inside of the solenoid frame 6 so as to be slidable in the axial direction. In addition, small-diameter step grooves 24a, 24b are provided on the inner sides of these facing portions 22a, 22b.

(Function) The solenoid of the present invention has excitation coils 17a, 1
By energizing 7b, the movable iron core 21 is magnetized,
A suction force is generated between one of the facing portions 22a, 22b and one end plate 12, 15 of the solenoid frame 11, and the movable iron core 21 moves to one side.
One opposing portion 22 of the movable core 21
a, 22b are the end plates 1 of the solenoid frame 11
2, 15, when the opposing parts 22a,
22b and the end plates 12, 15 are minimized and the attractive force is maximized, and at this position the movable iron core 2
1 is held electromagnetically. In addition, the excitation coil 17
After the energization to a and 17b is removed, the movable core 21 is self-held by the permanent magnet 19 on whose inner surface lines of magnetic force act orthogonally.

(Embodiment) Hereinafter, the configuration of an embodiment of the present invention will be described with reference to the drawings.

In FIGS. 1 and 4, reference numeral 11 denotes a solenoid frame, which is formed by bending a magnetic material such as an iron plate into a substantially U-shape, and has an end plate 12 and a pair of side plates 13, and a yoke 14. The cover plate 15 is attached between the tips of both side plates 13 of iron 14 and is formed into a rectangular shape from a magnetic material such as an iron plate. Note that the cover plate 15 and the end plate 12 are configured as end plates at both ends of the solenoid frame 11 in the axial direction. The end plate 12, side plate 13, and cover plate 15 of this yoke 14 are formed to have the same thickness and width w, and are formed with fitting holes 12a and 15a having the same inner diameter.

Inside the solenoid frame 11 is a cylindrical body 1.
The cylinder body 16 is formed of a non-magnetic material into a cylinder shape with openings at both ends, and both ends are connected to the fitting hole 12a of the yoke 14 and the fitting hole 15 of the cover plate 15.
It is fitted through a.

Excitation coils 17a,
A pair of coil bobbins 18a and 18b made of a non-magnetic material and wound with coil bobbins 17b are fitted together, and a permanent magnet 19 is fitted between the pair of coil bobbins 18a and 18b. Note that the winding direction and current direction of the windings of the pair of excitation coils 17a and 17b are set to be the same.

Moreover, this permanent magnet 19 is shown in FIGS. 2 and 3.
As shown in the figure, it is made up of an upper magnet 19a and a lower magnet 19b, and a semicircular arc-shaped fitting groove 20 that fits around the outer periphery of the cylinder body 16 is formed on the joint surface thereof.
The inner diameter side in contact with the cylindrical body 16 is magnetized to the north pole, and the outer diameter side in contact with the yoke 14 is magnetized to the south pole.

A movable iron core 21 is fitted into the cylindrical body 16 so as to be able to slide in the axial direction. It is formed to have a width x shorter than the width between the outer surface of the face plate 12 and the outer surface of the cover plate 15, and this width x is the movement stroke of the movable iron core 21. Opposing parts 22a and 22b having the same width w as the thickness of the end plate 12 and cover plate 15 of the yoke 14 are formed at both ends of the movable iron core 21, and at the center of the movable iron core 21, a movable Even when the iron core 21 moves in left and right directions, the width of the range facing the permanent magnet 19, that is, the permanent magnet 19
An opposing portion 23 having a width equal to the width x of the moving stroke is formed, and each opposing portion 22 at both ends is further formed.
Small diameter stepped grooves 24a, 24b are formed between a, 22b and the opposing portion 23 at the center. Also,
An output shaft 25 made of a non-magnetic material is protruded from one end surface of the movable iron core 21 .

Then, as shown in FIG. 1, the movable iron core 21, which is moving to the left, is attracted and held by the permanent magnet 19, that is, is in a self-holding state. Further, due to the magnetism of the permanent magnet 19, the side plate 13 of the yoke 14 is magnetized to the north pole, and the end plate 12 and the cover plate 15 of the yoke 14 are magnetized to the south pole.

Then, to drive the movable iron core 21 to the right,
The excitation coils 17a and 17b are energized so that the right end of the movable iron core 21 becomes the north pole and the left end becomes the south pole. By this energization, an attractive force is generated between the right end of the movable iron core 21 magnetized to the N pole and the cover plate 15 of the S pole, and the left end of the movable iron core 21 magnetized to the S pole and the S
A repulsive force is generated between the pole yoke 14 and the end plate 12, and this attractive force and repulsive force cause the movable iron core 2 to
1 moves to the right as shown in FIG.

When the opposing part 22b at the right end of the movable iron core 21 moving to the right is aligned with the inside of the cover plate 15, the leakage magnetic flux between the opposing part 22b and the cover plate 15 becomes minimum, and an attraction is generated between them. The force becomes maximum and the movable core 21 is electromagnetically held in this position. Note that the movable core 21 moves to the right due to inertia, and the opposing portion 22b of the movable core 21 comes off from the inside of the cover plate 15, and the stepped groove 2 on the side of the opposing portion 22b
4b faces the inside of the cover plate 15, the leakage magnetic flux between the opposing portion 22b and the cover plate 15 increases rapidly, and the force that moves the movable iron core 21 to the right is no longer generated. On the contrary, the facing part 22
A force is applied to return the b and cover plate 15 to the left so that they face each other, and even if the excitation coils 17a and 17b continue to be energized, the facing portion 22b does not pass through the cover plate 15, and the above-mentioned Opposing part 2 where the suction force is maximum
2b and the cover plate 15 are electromagnetically held in a precise position where they face each other.

This movement of the movable iron core 21 to the right causes the output shaft 25 to protrude and move by a stroke corresponding to the movement width x of the movable iron core 21.

Further, as shown in FIG. 4, when the excitation coils 17a and 17b are de-energized after the movable core 21 has moved to the right, the movable core 21 is in a state where it is attracted and held by the permanent magnet 19, that is, it is self-holding. become a state.

On the other hand, in order to return the movable iron core 21 from the state in which it has moved to the right to the state shown in FIG.
By energizing a and 17b in the opposite direction to that described above and reversing the polarity in which the movable core 21 is magnetized, that is, by magnetizing the right end of the movable core 21 to the S pole and the left end to the N pole, the movable core A repulsive force is generated between the right end of the movable iron core 21 and the cover plate 15, and the movable iron core 2
An attractive force is generated between the left end of the iron yoke 1 and the end plate 12 of the yoke 14, and the movable iron core 21 moves to the left. At this time, as described above, the facing portion 22a of the movable iron core 21
When the inner side of the end plate 12 of the yoke 14 faces and coincides with each other, the leakage magnetic flux between the opposing part 22a and the end plate 12 becomes the minimum, the attraction force generated between them becomes the maximum, and the movable member is moved to this position. Iron core 21 is held electromagnetically. Then, when the excitation coils 17a and 17b are de-energized, the movable core 21 is attracted and held by the permanent magnet 19, that is, becomes a self-holding state.

Further, the permanent magnet 19 that self-holds the movable iron core 21 is configured to have different magnetism in the radial direction, and the lines of magnetic force act orthogonally on the inner surface, so that the self-holding force of the movable iron core 21 facing the inner surface is strong.

Further, in the above embodiment, the permanent magnet 19 is
Although it is formed separately, it may be magnetized differently in the radial direction and formed integrally into an annular shape.

Further, the outer shape of the solenoid frame 11 may be formed into a cylindrical shape.

[Effect of idea]

According to the present invention, opposing parts corresponding to the thickness width of both end plates of the solenoid frame are formed at both ends of the movable iron core, and when the opposing parts of the movable iron core are aligned with the end plates of the solenoid frame, the opposing parts and The leakage magnetic flux of the end plate is minimized and the attractive force is maximized, making it possible to accurately hold the movable core at this position. Further, since the inner surface on which the lines of magnetic force of the permanent magnets magnetized differently in the radial direction face the movable core, the self-retention force of the permanent magnets is strong.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing an embodiment of the solenoid of the present invention, Figure 2 is a partially exploded perspective view of the solenoid, Figure 3 is a partial perspective view of its assembled state, and Figure 4 is a cross-sectional view of the solenoid in its operating state. FIG. 5 is a sectional view of a conventional solenoid. DESCRIPTION OF SYMBOLS 11... Solenoid frame, 12... End plate, 15... Cover plate as an end plate, 16... Cylindrical body, 17a, 17b... Excitation coil, 19... Permanent magnet, 21... Movable iron core, 22a, 22b...
Opposing portions, 24a, 24b... step portions.

Claims (1)

[Scope of Claim for Utility Model Registration] A solenoid frame made of a magnetic material with end plates provided at both ends in the axial direction, and a non-magnetic material disposed inside the solenoid frame and having both ends fitted through the end plates. a pair of excitation coils fitted on the outer periphery of the cylindrical body; and a permanent magnet fitted between the pair of excitation coils on the outer periphery of the cylindrical body and magnetized with different polarities in the radial direction. , is fitted into the cylindrical body so as to be slidable in the axial direction,
A solenoid comprising: a movable iron core provided with opposed parts corresponding to the thickness and width of each end plate of the solenoid frame at both ends, and a movable iron core provided with a step groove of a small diameter on the inside of the opposed part.