JPH0877906A - Electromagnetic actuator - Google Patents

Abstract

PURPOSE: To provide an electromagnetic actuator compact in size and capable of performing a high-speed operation. CONSTITUTION: Yokes 1 and 2 made of magnetic materials have oscillating gaps 4a and 4b formed between contact polar pieces 1b and 2b and 1c and 2c placed oppositely to each other and, permanent magnets 5a and 5b placed almost in the center positions of the conductive magnetic paths of the respective yokes and provided and two coils 6a and 6b hollow in their center parts are placed between the oscillating gaps 4a and 4b and the permanent magnets 5a and 5b. In the coils 6a and 6b, there are provided movers 8 made of magnetic materials for freely rocking in oscillating gaps 4a and 4b between the contact polar pieces with a fulcrum 7 placed between the permanent magnets 5a and 5b as an axis. The coils 6a and 6b are wound around a bobbin 3, pocket parts 3a for holding the respective inserted contact polar pieces 1b, 1c, 2b and 2c of the yokes 1 and 2 are provided in the bobbin 3 and the yokes 1 and 2 are fixed to the bobbin 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing type electromagnetic actuator having a polar structure.

[0002]

2. Description of the Related Art As a conventional oscillating electromagnetic actuator having a polar structure, for example, the one proposed in Japanese Patent Publication No. 5-86044 is known. FIG. 7 is a sectional view showing the outline of the proposal. In the drawing, reference numeral 11 denotes a yoke having a U-shaped cross section, and the left and right yoke leg portions 12 each have a permanent magnet 13 arranged in a predetermined polarity at the tips thereof and bent into an L-shape through these permanent magnets 13. A pole piece 15 having a contact piece 14 is provided, the left and right contact pieces 14 face each other to form a swing gap, and the left and right yoke legs 12 are connected via a lower yoke floor portion 16. It forms an integral magnetic path. Inside the U-shaped yoke 11, a hollow coil body 17 in which a magnetic field is generated vertically from the center of the yoke floor 16
Is provided, and further penetrates the hollow portion of the coil body 17 in the vertical direction, and the swing gap between the two armature pieces 14 is swingable left and right around a fulcrum 18 near the yoke floor 16. A mover 19 made of a material is provided to form an electromagnetic actuator. By flowing a current of a predetermined polarity through the coil body 17 configured as described above, the magnetic force of the coil body 17 and the magnetic force of the permanent magnet 13 act on the mover 19 in a synergistic or offset manner to move the mover 19 in a predetermined direction. Permanent magnet 1
It is held by 3.

[0003]

Recently, it has been strongly demanded that the electromagnetic actuator as described above be small in shape and operate at high speed. However, the electromagnetic actuator having the structure shown in FIG. 7 has a problem that it prevents the speeding up in the following points. That is, the first problem is that the fulcrum 18 of the mover 19 is located near the yoke floor 16, and the swinging portion that requires an operation stroke is the yoke leg 12.
Since it is located at the most tip end part, the effective turning radius R of the swinging motion increases, and I = Σmi ri ² Σ increases the inertia moment I that can be represented by the sum of each mass point m from i = 1 to n It was difficult to increase the operation speed. In addition, as a second problem, the magnetic force for swinging or holding the mover 19 acts on the armature piece 14 near the tip of the mover 19.
It is difficult to increase the suction force and the holding force because it is only one point in contact with, and this also makes it difficult to increase the operation speed and stability.

Further, in order to increase the attraction force and the holding force by the magnetic force, it is necessary to make the cross-sectional area of the magnetic path including the yoke leg 12, the pole piece 15 and the armature piece 14 as large as possible. The conventional electromagnetic actuator shown in FIG.
The permanent magnets 13 and the pole pieces 15 are concentratedly provided in a limited space between the permanent magnets 13 and 9. Further, since the permanent magnets 13 are magnetized in the thickness direction, it is necessary to secure a coercive force as a magnet. The required thickness is required and therefore the permanent magnet 13
However, the plate thickness of the yoke leg 12 and the pole piece 15 allowed in the remaining space except the thickness is limited, and a sufficient magnetic path cross section cannot be secured. Further, it is desirable in manufacturing that the pole piece 15 is formed by bending a material having a uniform plate thickness to form the armature piece 14. Therefore, the magnetic path cross section of the armature piece 14 is defined as the thickness of the pole piece 15. There is also a third problem in that the attraction force and the holding force of the armature piece 14 that directly exerts a magnetic force on the mover 18 cannot be increased due to the above-mentioned problem. Further, since the permanent magnet 13 cannot secure a sufficient thickness, and because the permanent magnet 13 is arranged at the end portion of the yoke leg portion 12, a large amount of ineffective magnetic flux leaks, so that the effective magnetic flux acting on the mover 19 decreases and the permanent magnet 13 becomes permanent. There is also a problem that the magnetic flux of the magnet 13 cannot be fully utilized. Also,
In the conventional structure, when the movable element 19 is actuated, the armature piece 14 also pulls the armature piece 14 in one direction in the upward direction in the drawing, so that a load is applied to the fulcrum 18 and the durability of the portion of the fulcrum 18 deteriorates. . An object of the present invention is to solve these problems and to provide an oscillating electromagnetic actuator capable of high-speed operation without impairing miniaturization.

[0005]

In the electromagnetic actuator of the present invention, each of the yokes made of a magnetic material has an independent symmetrical U-shape, each yoke forms a magnetic path, and both ends in parallel are The armature is formed so that the armature pieces of both yokes and the armature pieces of one end of the two yokes and the armature pieces of the other end of the two yokes face each other at a predetermined interval to form two swing gaps. The two yokes and the magnetic pole surface of the permanent magnet are provided in contact with each other at approximately the center of the magnetic path of each yoke, and the other magnetic pole surface is provided on one yoke of the permanent magnet at the predetermined interval. Two permanent magnets that are opposed to each other and are arranged in the same predetermined direction, and two central spaces are provided in two spaces between the opposed permanent magnets inside the two opposed yokes and the two swing gaps. Has a hollow shape and the generated magnetic field is in the direction of both yokes It has a length that connects two coils wound parallel to the magnetic path and a space between at least two swinging spaces that penetrates through the space between the center of the two coils and the facing permanent magnets. Then, the swing gap between the armature pieces is composed of a movable element made of a swingable magnetic material with a fulcrum provided between the facing permanent magnets as an axis.

Further, the two coils are wound around an integrated bobbin, and each bobbin is fitted with each contact piece portion and each permanent magnet at both ends of the two yokes in parallel to each other. A configuration is also provided in which a pocket portion for removably positioning and holding is provided.

Further, the output heads may be provided at two positions on both ends of the mover so as to take out mechanical output from one or both of the output heads. Further, as a fixing means for the bobbin and the two yokes, a heat-shrinkable tube or a mold corresponding to the outer shape, or a bobbin or a yoke provided on either of the yokes and a corresponding pawl stopper may be used for fixing.

Further, the fulcrum is provided as a convex support shaft or a concave shaft fitting portion at a predetermined position of the bobbin, and a concave shaft for fitting the convex support shaft of the bobbin at the swing center position of the mover. It is also possible to provide a flexible and elastic slide seat provided with a convex support shaft that fits into the fitting portion or the recessed shaft fitting portion of the bobbin.

[0009]

With this structure, the swing radius of the mover becomes about 1/2 of the distance between the two swing spaces, and can be shortened to about half the swing radius of the conventional mover. Therefore, the moment of inertia proportional to the square of the swing radius can be significantly reduced. Further, the suction force and the holding force can be applied to the mover at two places. At the same time, substantially the same suction force acts on both ends of the mover in opposite directions, so that both suction forces are canceled and the load on the fulcrum can be significantly reduced.

By providing the permanent magnet at the center of the magnetic path of each yoke, the thickness of the yoke including the contact piece of the conventional electromagnetic actuator and the permanent magnet can be increased. Moreover, since two output heads can be provided, the degree of freedom in taking out the output can be increased.

Further, the bobbin and the two yokes are fixed by a heat-shrinkable tube or a mold corresponding to the outer shape, or by a pawl provided on either the bobbin or the yoke and a corresponding pawl stopper, thereby facilitating the fixing work. Become.

Further, a convex support shaft or a concave shaft fitting portion is formed on the bobbin, and the movable shaft is fitted with a concave shaft fitting portion or a bobbin shaft fitting portion. Assembly can be simplified by providing a convex support shaft.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of the electromagnetic actuator of the first embodiment, and FIG. 2 is a perspective view for explaining the assembling method thereof. In these drawings, reference numerals 1 and 2 are independent U-shaped yokes formed by bending a plate-shaped magnetic material. The yokes 1 and 2 form magnetic paths 1a and 2a, and both ends of which are bent in parallel in a U-shape form armature pieces 1b, 1c, 2b and 2c. These yokes 1 and 2 are provided with pocket portions 3a provided on the upper, lower, left and right sides of a bobbin 3 formed of synthetic resin or the like so that the armature pieces 1b, 1c, 2b and 2c at both ends are in the direction of arrow A in FIG. Inserted, the armature piece 1b of the yoke 1 and the armature piece 2 of the yoke 2
b and the armature piece 1c of the yoke 1 and the armature piece 2c of the yoke 2
Are positioned and held by the bobbin 3 so as to face each other and form swinging gaps 4a and 4b of a predetermined size. Also,
When the armature pieces 1b, 1c, 2b, 2c are inserted into the pocket portion 3a, permanent magnets 5a, 5b are inserted in the pocket portions 3b provided on the left and right of the bobbin 3 at substantially the center position in advance. When the yoke 2 and the yoke 2 are mounted on the bobbin 3, the permanent magnets 5a and 5b are attracted by the magnetic force to the side surfaces of the magnetic flux paths 1a and 2a of the yokes 1 and 2, respectively. And
The two permanent magnets 5a and 5b are arranged so as to face each other at a predetermined interval. At this time, the permanent magnets 5a and 5b are arranged so that the magnetic field directions are the same. In this embodiment, the magnetic pole 1a of the yoke 1 is provided with the N pole of the permanent magnet 5a, and the magnetic flux path 2a of the yoke 2 is provided with the S pole of the permanent magnet 5b.

Armature pole pieces 1b, 2b, 1c, 2c of the bobbin 3
Two coils 6a and 6b are wound in the upper and lower two spaces in the figure between the pocket 3a into which is inserted and the pocket 3b into which the permanent magnets 5a and 5b are inserted. The coils 6a and 6b are wound in such a manner that the generated magnetic field is vertical in the figure, that is, parallel to the magnetic flux paths 1a and 2a of the yokes 1 and 2.

A central portion 3c of the bobbin 3 has a hollow shape, and a magnetic material swingable in the left and right directions in the drawing is centered on the fulcrum 7 provided between the two permanent magnets 5a and 5b in the central portion 3c. Is provided with a mover 8. The fulcrum 7 is provided substantially at the center of the mover 8 as well.
This shortens the swing radius of the mover 8 to reduce the moment of inertia proportional to the square of the radius. The mover 8 is located near the fulcrum 7, that is, the permanent magnet 5
In order to efficiently cause the magnetic field of the permanent magnets 5a and 5b to act on the mover 8, the portions close to the a and 5b have the permanent magnets 5a and 5b.
5b is formed to be wide so as to be narrow between the two, and both ends 8a and 8b are formed thin to reduce the moment of inertia of the mover 8. And both ends 8a,
The end faces of the 8b facing the armature pieces 1b, 2b, 1c, 2c are provided with an appropriate angle so as to be parallel to the end surfaces of the armature pieces when the armature pieces are attracted to the armature pieces, so that the holding force is improved efficiently. You can get it. Further, one end 8b is covered with a non-magnetic material cap 8c made of a resin or the like for buffering when the movable element 8 swings and for preventing excessive suction and widening the operation range. The other end 8a is provided with an output head 8d which also serves as a cap 8c and takes out the swing output of the mover 8 to the outside. After inserting the two yokes 1 and 2 into the bobbin 3 having such a configuration, the heat-shrinkable tube 9 is covered from the direction of the arrow B as shown in FIG. Then, the yokes 1 and 2 are fixed to the bobbin 3 to complete the electromagnetic actuator of the embodiment.

In the electromagnetic actuator thus constructed, the magnetic flux of the permanent magnets 5a and 5b passes through the magnetic path in the direction of the arrow shown by the broken line. That is, since the permanent magnets 5a and 5b are provided at the substantially central positions of the magnetic flux guide paths 1a and 2a,
The magnetic flux is shunted in the vertical direction in the drawing in the magnetic guide paths 1a and 2a, and the oscillating gap 4 from the armature pole pieces 1b, 2b, 1c and 2c.
a, 4b and both ends 8a, 8b of the mover 8 pass through the opposing magnetic path and flow in a path returning to the original state. On the other hand, the magnetic flux of the coils 6a and 6b passes through the path indicated by the chain double-dashed line. That is, the magnetic flux that has passed through the mover 8 is shunted to the left and right at the swing gaps 4a and 4b via both ends 8a and 8b.
Returning from b, 2b, 1c, 2c to the original mover 8 through the magnetic paths 1a, 2a. If the direction of the magnetic flux due to the coil current of a certain polarity is the arrow direction from the bottom to the top as shown in the figure, the magnetic flux directed toward the armature piece 1b in the swing gap 4a cancels out the magnetic flux of the permanent magnets 5a and 5b. And the armature piece 2
The magnetic flux in the b direction is synergistic with the magnetic flux of the permanent magnets 5a and 5b. Further, in the swinging gap 4b, the magnetic flux directed to the armature piece 2c is offset by the magnetic flux of the permanent magnets 5a and 5b, and the magnetic flux directed to the armature piece 1c is synergized with the magnetic flux of the permanent magnets 5a and 5b. Therefore, the end 8a of the mover 8 has the armature piece 2b.
In addition, the end 8b is attracted to the armature piece 1c. When the coil current is cut off, the end portions 8a and 8b are held by the armature piece 2b and the armature piece 1c by the magnetic fields of the permanent magnets 5a and 5b, respectively. That is, the both ends 8a and 8b of the mover 8 are
The suction force and the holding force in the same direction work at
The mover 8 can be operated at high speed and can be stably held.

FIG. 3 is a sectional view showing the second embodiment.
In this embodiment, the end 8 of the mover 8 described in the first embodiment is used.
An output head 8e similar to the output head 8d at the end 8a is provided at b.
Is provided so that the mechanical output can be taken out from both output heads 8d and 8e. Since the other parts are the same as those in the first embodiment, the description thereof will be omitted.

FIGS. 4 and 5 are embodiments showing other means for fixing the yokes 1 and 2 to the bobbin 3, respectively. As shown in FIG. 4, as in the first embodiment, the yokes 1 and 2 are inserted into the bobbin 3 and then the mold 10 is made of synthetic resin or the like.
Is covered and fixed in the direction of the arrow B. In the method shown in FIG. 5, fixing claws 3d and 3e are provided at the upper and lower pocket portions of the bobbin 3, respectively, and when the yokes 1 and 2 are inserted into the bobbin 3, 1d, 1e and 2d of the yokes 1 and 2 are inserted.
And 2e surface with fixed claws 3d and 3e locked and yokes 1 and 2
Is to fix. According to this embodiment, fixing parts such as the heat-shrinkable tube 9 and the mold 10 are not required, and the manufacturing process is simplified. Moreover, the heat-shrinkable tube 9 and the mold 1 are made.
The external dimensions can be reduced by 0. Further, as a modification of this embodiment, the claws may be formed on the yokes 1 and 2 by extrusion and the claw stoppers may be formed on the bobbin side by molding.

FIG. 6 is a partial cross-sectional view showing the embodiment of the fulcrum 7 which is the swing center of the mover 8 with a focus on the fulcrum 7. In the figure, the central portion 3c of the bobbin 3
Protrusions are provided on the left and right sides of the mover 8 at the position serving as the fulcrum 7 of the inner wall of the above, to form the support shaft 3f. On the other hand, a through hole 8f is provided in the swing center of the mover 8, and a sliding seat 8g made of resin or the like having flexibility and elasticity is provided along the inside of the through hole 8f and the left and right outer edges in the figure. It is inserted and the hole through which the sliding seat 8g penetrates forms a shaft fitting portion 8h. Then, the support shaft 3f formed by the two convex portions
Is fitted to the shaft fitting portion 8h of the through hole of the sliding seat 8g to swingably support the mover 8. When the movable element 8 is inserted into the central portion 3c of the bobbin 3 for assembly, when the support shaft 3f comes into contact with the outer edge portion of the sliding seat 8g, the sliding seat 8g has flexibility, so that it is recessed according to the support shaft 3f. The convex support shaft 3f can be locked to the shaft fitting portion 8h of the hole through which the sliding seat 8g penetrates. According to this embodiment, parts such as a shaft for the fulcrum 7 are unnecessary, and the manufacturing process is simplified. Further, as a modification of this embodiment, a convex support shaft is provided on the sliding seat 8g of the mover 8 and a concave shaft fitting portion corresponding to the support shaft of the protrusion is provided on the bobbin 3 side, so that Sliding seat 8
It is also possible to fit the convex support shaft of g into the recessed shaft fitting portion on the bobbin 3 side. The present invention is not limited to the above-mentioned embodiments, and can be modified and carried out without changing the gist.

[0020]

According to the present invention, the following effects can be expected. 1. By providing a swinging fulcrum at approximately the center of the mover to reduce the effective operation radius, the moment of inertia of the mover can be reduced and the mover can be swung at high speed. 2. Also, by providing a swing fulcrum at the center position of the mover, the suction force and the holding force act on the mover at two points, so that the mechanical output can be strengthened without impairing downsizing, resulting in movement. The child can be swung at high speed.
Further, since the holding force acts at two places, the holding stability at rest can be increased. 3. Further, by providing the swing fulcrum at the center position of the mover, the load applied to the swing fulcrum can be reduced, wear can be prevented, and durability can be improved. 4. Since the permanent magnet is provided at the center of the yoke, the permanent magnet has a space more than that of the conventional one, and the plate thickness of the magnetic flux path and the armature piece of the yoke can be increased. It is possible to increase the suction force and the holding force applied to the. 5. Similarly, by providing a permanent magnet in the center of the yoke, it is possible to make a space more than the conventional one by the amount of the contact piece, and it is possible to increase the thickness of the permanent magnet. It has become possible to increase the coercive force. Moreover, by providing it in the central position, it is possible to reduce the leakage magnetic flux and increase the effective magnetic flux acting on the mover. 6. When two output heads are provided at both ends of the mover, the range of use can be expanded. 7. Further, according to the present invention, since many of the respective constituent parts have symmetrical shapes, the number of parts can be reduced, so that the manufacturing equipment can be simplified and the number of assembling steps can be shortened.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of a first embodiment of the present invention.

FIG. 2 is a perspective view showing an assembling method of the first embodiment.

FIG. 3 is a sectional view showing the configuration of the second embodiment.

FIG. 4 is a perspective view of an embodiment in which a yoke and a bobbin are fixed using a mold.

FIG. 5 is a perspective view of an embodiment in which a yoke and a bobbin are fixed using a fixing claw.

FIG. 6 is a partial cross-sectional view showing an example of one configuration of a fulcrum.

FIG. 7 is a sectional view showing the structure of a conventional electromagnetic actuator.

[Explanation of symbols]

1, 2 ... Yoke, 1a, 2a ... Magnetic path, 1b, 1c, 2
b, 2c ... Contact piece, 1d, 1e, 2d, 2e ... Surface, 3 ...
Bobbins 3a, 3b ... pockets, 3c ... central part, 3
d, 3e ... Fixed claw, 3f ... Support shaft, 4a, 4b ... Swing gap, 5a, 5b ... Permanent magnet, 6a, 6b ... Coil, 7 ...
Support point, 8 ... Mover, 8a, 8b ... End, 8c ... Cap, 8d, 8e ... Output head, 8f ... Through hole, 8g ... Sliding seat, 8h ... Shaft fitting section, 9 ... Heat shrinkable tube, 10 …
Formwork.

Front Page Continuation (72) Inventor Yasushi Takahashi 2-25-7 Higashino, Urayasu City, Chiba Kages Co., Ltd.

Claims (7)

[Claims] 1. A yoke having a pair of opposing pole pieces made of a magnetic material, a coil and a permanent magnet for applying a magnetic field to the yoke, and a pole piece made of a magnetic material and facing each other driven by the magnetic field of the coil. It is equipped with a mover that can swing the formed swinging gap and an output head that is directly connected to this mover and works in conjunction with it. In an electromagnetic actuator that takes out the output through an output head and holds the mover with a permanent magnet, each yoke has an independent symmetrical U-shape, and each yoke forms a magnetic path and both ends are in parallel. Are arranged so that the armature pole pieces are formed and the armature pole pieces of one end of both yokes and the armature pole pieces of the other end of the two yokes face each other at a predetermined interval to form two swing gaps. Two yokes And a magnetic pole surface of a permanent magnet is provided in contact with a substantially central position of the magnetic flux path of each yoke, and the other magnetic pole surface faces one magnetic pole surface of a permanent magnet provided on the other yoke at a predetermined interval. Two permanent magnets whose polar directions are arranged in the same predetermined direction and two spaces between the opposing permanent magnets inside the two opposing yokes and the two swing gaps, and the central part is hollow The two coils are wound so that the direction of the generated magnetic field is parallel to the magnetic paths of both yokes, and at least two swings are provided in the center of the two coils and through the space of the facing permanent magnets. A movable element which has a length connecting the moving spaces and which can swing the swinging gap between the armature pieces about a fulcrum provided between facing permanent magnets as an axis. Electromagnetic actuator to. 2. The two coils are wound around an integrated bobbin, and the bobbin is provided with the respective armature pieces at both ends of the two yokes in parallel and the permanent magnets. The electromagnetic actuator according to claim 1, further comprising a pocket portion for removably positioning and holding the armature. 3. The electromagnetic actuator according to claim 1, wherein the output head is provided at two positions on both ends of the mover. 4. The bobbin and the two yokes are fixed by a heat-shrinkable tube.
Alternatively, the electromagnetic actuator according to Item 3. 5. The electromagnetic actuator according to claim 2, wherein the bobbin and the two yokes are fixed by a mold frame corresponding to an outer shape including the bobbin and the yoke inserted in the bobbin. 6. The electromagnetic actuator according to claim 2, wherein the bobbin and the two yokes are fixed by a claw provided on either the bobbin or the yoke and a corresponding claw stopper. 7. The fulcrum is provided at a predetermined position of the bobbin as a convex support shaft or a concave shaft fitting portion, and the convex support shaft of the bobbin is fitted at a swing center position of the mover. A flexible and elastic slide seat provided with a concave shaft fitting portion or a convex support shaft that fits into the concave shaft fitting portion of the bobbin is provided. The electromagnetic actuator according to any one of claims 2 to 6.