WO2014136233A1

WO2014136233A1 - Rotary actuator

Info

Publication number: WO2014136233A1
Application number: PCT/JP2013/056226
Authority: WO
Inventors: 石川　敏之; 雅幸本柳
Original assignee: 沖マイクロ技研株式会社
Priority date: 2013-03-07
Filing date: 2013-03-07
Publication date: 2014-09-12

Abstract

[Problem] To provide a novel actuator, the purpose of which is to ensure a retention force that keeps said actuator in a stopped state without power despite the case thereof being formed from a lightweight, easily moldable synthetic-resin material. [Solution] This actuator (1) comprises the following: a case (2) that comprises a nonmagnetic material and provides a prescribed internal space; an electromagnet (3) provided inside said case; two magnets (6) that face a pole face of the electromagnet and are laid out such that opposite pole faces of said magnets lie at a separation from each other in the same plane, said plane being parallel to the aforementioned pole face of the electromagnet; an arm (5) that holds the two magnets and swings back and forth in a plane parallel to the aforementioned pole face of the electromagnet with an air gap between said pole face and the arm; an output shaft (4) that axially supports the arm inside the case and axially outputs the force of the aforementioned swinging; and a magnetic-circuit-forming body (7) disposed inside or outside the case so as to form a magnetic circuit between the non-facing poles of the electromagnet and the magnets laid out as described above. Said magnetic-circuit-forming body (7) is formed from a rectangular plate.

Description

Rotary actuator

The present invention belongs to the technical field of rotary actuators.

As one of the rotary actuator (hereinafter referred to as “actuator”) mechanism that outputs the reciprocating rotational force as a driving force, an arm that is pivotally supported on the output shaft is reciprocally rotated using electromagnetic force (hereinafter referred to as the “actuator”). There is a mechanism to “oscillate”). An example of the actuator is disclosed in the patent documents 1 and 2 of the prior application by the applicant of the present application.

The actuator disclosed in Patent Document 1 includes an arm that is cantilevered on an output shaft in a case, and two magnets (permanent magnets) that are separated from each other by being reversed in polarity (a state in which different polarities are juxtaposed). And two electromagnets arranged opposite to each other so as to be sandwiched with air gaps on both pole surfaces. Then, the polarity of the electromagnet is appropriately switched to swing along the magnetic pole surface of the electromagnet by electromagnetic interaction, and this swinging force is extracted from the output shaft as an output.

In addition, the actuator disclosed in Patent Document 2 is an improvement of the technique disclosed in Patent Document 1, and includes one electromagnet and one magnetic pole side on the counter-electromagnet side of the two magnets held by the arm. In this configuration, the magnetic poles of the magnet covered with one back yoke (magnetic material) are generated in a single direction. As a result, since both the magnetic pole faces of the magnet are opposed to the coil when energized, a large starting torque can be obtained, and the number of electromagnets can be reduced to reduce the number of parts and reduce the size and weight (especially thinner). Is intended.

Japanese Patent Laid-Open No. 10-174409 JP 2009-38874 A

In general, actuators are incorporated as drive sources in various industrial equipment, and in addition to these equipments, in addition to reduction in size and weight and reliability of operation, energy saving has become an important requirement in recent years. ing.

The actuator of Patent Document 2 already disclosed by the applicant of the present invention is smaller and lighter than the actuator of Patent Document 1, but it is a storage housing because of leakage of magnetic flux and formation of a closed magnetic circuit in the case. It is necessary to form the case using a magnetic material such as metal. The same applies to other actuators. Recently, with the application of electromagnets and ferromagnetic elements of magnets, miniaturization has progressed with the same function. For this reason, the weight ratio of the case is increased, and reducing the weight of the case has become an issue for further weight reduction.

In addition, the actuator is not always operated like a motor, but is used as a driving source to be switched appropriately, so that the time during which the actuator is stopped tends to be longer. And since it is necessary to hold | maintain the stop state reliably, the electromagnet was supplied with electricity, and the holding | maintenance was stabilized by the magnetic force.

The actuators disclosed in Patent Documents 1 and 2 have a structure in which a closed magnetic path is formed between a magnet and a case made of a magnetic material even in a non-energized state in which an electromagnet is not energized, so that the arm can be held reliably. ing. In the configuration of the actuator shown in Patent Document 2, since the magnetic flux density of the magnet is concentrated on the electromagnet side using the back yoke, a large starting torque can be obtained during energization.

However, the magnetic path when not energized is an electromagnet core, a magnet on one side opposite to this, a back yoke, a magnet on the other side, a case, and a circulating magnetic path (closed magnetic path) leading to the core of the electromagnet. Although formed, this magnetic path goes through the case, so that the spatial distance from the magnet not facing the core to the case becomes long, the magnetic flux is dispersed, and the magnetic resistance becomes large. For this reason, there is a problem that it is difficult to obtain a large holding force (a magnetic attractive force due to a magnetic flux from the magnet).

Therefore, in the present invention, in order to further reduce the weight, the case is made of a synthetic resin material that is lightweight and has excellent moldability, while the case is in a stopped state when no current is applied as an allowance for a non-magnetic material. A novel actuator for securing the holding force is provided.

The actuator according to the present invention is configured as follows in order to solve the above problems.

That is, a case made of a non-magnetic material capable of securing a predetermined internal space, an electromagnet installed in the case, and a magnetic pole surface facing the magnetic pole surface of the electromagnet and opposite to each other along the surface direction of the magnetic pole surface Two magnets that are separated from each other ("displacement of different polarities"), an arm that holds the magnet and swings in the plane direction of the magnetic pole surface with an air gap and the magnetic pole surface of the electromagnet, and the arm in the case A magnetic circuit ("magnetic path") is formed between the output shaft that supports the shaft and outputs the swinging force in the shaft, and the opposite magnetic poles of the electromagnet and the magnet in the opposed state. And a magnetic path forming body disposed inside or outside.

The case that can secure the above internal space is generally a box-like body with a closed space, but depending on the installation site of industrial equipment, a part of the space is opened as long as a certain shape retaining force can be secured. It may be a net plate molded body or a frame-shaped body. Usually, it is molded with a synthetic resin material in order to reduce the weight. In addition, the two magnets are separated from each other, and the magnetic pole surfaces of the magnets arranged individually are opposite to each other (one is an N pole and the other is an S pole), and the magnetic pole surfaces are along the swing surface. In addition, they are arranged side by side with a separation distance that matches a desired swing distance (arc shape).

Further, the magnetic path forming body is formed of a magnetic material, and is intended to concentrate magnetic flux and reduce the size and weight, and is preferably a belt-like plate or wire, preferably a narrow and thin and long plate or wire. Form into a body. This magnetic path forming body is disposed inside or outside the case, but is preferably disposed along the outer side surface or inner side surface of the case or in an embedded state. Further, depending on the workability, the inner installation and the outer installation may be combined, or may be integrally formed with the case.

In particular, in the arrangement of the magnetic path forming body, it is more preferable that the position be the shortest path as long as it does not interfere with the swing of the arm. For example, a U-shape may be used in which the arm is detoured from the magnetic pole side on the opposite side of the core to the magnetic pole side on the opposite side of the magnet.

Further, as the arrangement configuration of the magnetic path forming body, a part of the case of the non-magnetic material is made of a magnetic material to be a base of the electromagnet, and is a long strip plate connected to the base and extended. It is also possible to adopt a configuration in which the tip of the magnet is brought close to the magnetic pole surface of the magnet on the opposite side from the outside of the case.

Furthermore, the tip of the magnetic path former that is close to the magnetic pole surface of the magnet on the opposite side is flat and faces the magnetic pole surface of the magnet. It may be formed to concentrate the magnetic flux (or improve the magnetic flux density) so as to increase the magnetic adhesion force at the time of stopping and holding. When the electromagnet is energized, the protrusion acts as a holding magnetic pole, and the swing torque can be increased.

Furthermore, the present invention is characterized in that a back yoke for covering the magnetic poles is provided separately on the opposite side of the two magnets.

Since the actuator according to the present invention is configured as described above, the following effects can be obtained.

That is, the invention of the present application can be formed of a non-magnetic material such as a synthetic resin material whose weight is reduced, so that the weight of the entire actuator can be reduced, and without passing through the case, the core, magnet, magnetic path forming body, and It is possible to form a closed loop magnetic path in which the magnetic lines of force leading to the core are concentrated. For this reason, without increasing the magnetic resistance, in other words, without attenuating the magnetic flux from the macnet, a large magnetic action (attraction force) is generated between the core and the stop state is stably and strongly Can be held.

In addition, in the conventional actuator where the case is made of a magnetic material (mainly metal), a protruding shape like a core is formed at the corresponding position in the case in order to prevent the magnetic lines of force from dispersing in the case and reducing the magnetic flux density. However, in the configuration of the present application, the magnetic path forming body is arranged in a non-magnetic case with a narrow, long thin plate or linear magnetic path forming body. Can be concentrated, and sufficient magnetic force can be secured.

Furthermore, since the magnetic flux is concentrated by the magnetic path forming body, the setting position can be easily adjusted. In addition, when the case itself is used as a magnetic path, it was necessary to form a boss for concentrating the magnetic flux on the magnet, but this is not necessary, and it can be applied only by bending long strips. It is possible to improve workability and assemblability.

Further, when the structure of claim 3 is adopted, the magnetic path forming body can be attached after the case is assembled so that the installation surface of the electromagnet and the magnetic pole surface of the magnet are brought close to the outside of the case, thereby reducing the number of parts. In addition, it has the effect that assembly can be facilitated and production efficiency can be improved.

Further, when the structure of claim 4 is adopted, the back yoke interposed between the magnetic pole surface of the magnet and the tip of the magnetic path forming body suppresses the diffusion of the magnetic flux, in other words, suppresses the attenuation of the magnetic resistance. As a result, it is possible to expect an effect of maintaining a more reliable holding force.

It is a partially cutaway perspective view showing an actuator. It is an assembly perspective view showing an actuator. FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. FIG. 2 is a cross-sectional view taken along the line BB ′ of FIG.

Hereinafter, embodiments of an actuator according to the present invention will be described in detail with reference to the drawings.

The actuator 1 of the present embodiment is a drive element that is incorporated in industrial equipment and connected to a predetermined portion thereof to transmit a swinging force between a certain angle. The main components are a case 2 for housing components, an electromagnet 3 installed on the inside thereof, an output shaft 4 supported by the shaft in the case 2, and an arm that swings while being supported by the output shaft 4. 5, a magnet 6 (permanent magnet) attached to the arm 5, and a magnetic path forming body 7. Note that the actuator 1 according to the present embodiment has no vertical relationship in terms of specifications, but in the description of the present specification, for convenience, the description will be made using the vertical relationship according to the drawing display.

The case 2 has a substantially cylindrical box shape having a predetermined internal space, and constitutes a bottom surface of the case 2 and serves as a mounting base for the electromagnet 3, the output shaft 4, the arm 5, and the like, It consists of a bowl-shaped (bottomed cylindrical shape) crowned body 21 that divides a closed space by being fitted so as to cover the base 20. The base 20 is made of a magnetic material (for example, steel such as a plated steel plate or silicon steel plate, iron oxide, chromium oxide, ferrite, cobalt, etc.), and the crown body 21 is made of a non-magnetic lightweight material such as a synthetic resin material. is doing. An electromagnet 3 is disposed at a substantially central portion of the base 20.

The electromagnet 3 includes a columnar magnetic core 30 (generally an iron core) and an electromagnetic coil 31 (hereinafter referred to as “coil”) tightly wound around the side surface thereof. (Vertical installation). In this case, it is preferable that the height of the core 30 and the densely wound height of the coil 31 (the height in the upward direction of the winding surface) are aligned.

In the case 2 at a position where it does not interfere with the electromagnet 3, the output shaft 4 is erected (vertical direction) and is pivotally supported. The output shaft 4 serves as an output part to the outside of the actuator 1, and is supported by a bearing 22 projectingly provided on the upper surface 21 u of the crowned body 21, and its upper end part is predetermined from the bearing 22. It is in a state of protruding upward in height. An arm 5 is attached to the output shaft 4.

The arm 5 is generally fan-shaped in plan view, and the fan-shaped main portion is attached in a cantilever manner as a support point of the output shaft 4. On the lower surface side of the arm 5, two

magnets

6, 6 are juxtaposed at a predetermined interval (“separate juxtaposition”). This predetermined interval is set according to the desired swing distance (arc length) of the arm 5. Each magnet 6 forms a columnar body such as a cylinder or a prism, and is attached in a state where the magnetic pole surface of the magnet 6 is substantially flush with the lower surface of the arm 5 and is fitted or fitted. Further, the magnetic pole surfaces 60 and 61 of the two

magnets

6 and 6 are set to different poles (N pole and S pole), and are opposed to the upper end face 30u of the core 30 of the electromagnet 3 with an air gap. ing.

Also, on the upper surface side of the arm 5, back yokes 50 are respectively embedded in an embedded manner so as to cover each of the magnets 6 so as to be substantially parallel to the opposite magnetic pole surfaces of the two magnets 6. In the arm 5, a thin portion 53 having a predetermined thickness is formed between the bottom surfaces of the concave portion 51 for embedding the magnet and the concave portion 52 for embedding the back yoke. The arm 5, the magnet 6, and the back yoke 50 are integrated by inserting (or press-fitting) the magnet 6 and the back yoke 50 into each of the

recesses

51 and 52 and sandwiching the thin portion 53. I am trying. Thereby, since it can hold | maintain using the magnetizing force of the magnet 6 and the back yoke 50, it has become simpler and reliable than the conventional adhesion system and the fixing system by insert mold.

The operation of the actuator 1 having the above-described configuration is already disclosed in Patent Documents 1 and 2, and can be summarized by switching the energization direction of the electromagnet 3 to the coil 31 appropriately (or periodically). Since the polarity of the electromagnet 3 is switched, a magnetic attraction force acts between the magnet 6 on one side and a magnetic repulsion force on the other side between the magnetic poles of two magnets 6 arranged in parallel. Thus, a swinging force that turns the arm 5 is generated. This rocking force is supplied as an output via the output shaft 4 to the attachment site of the equipment.

Next, the magnetic path forming body 7 which is one of the characteristic elements of the present invention is a long strip-shaped thin plate body formed of a magnetic material capable of concentrating magnetic lines of force. The magnetic path forming body 7 has one end 70 connected to the edge of the base 20 that occupies substantially the entire bottom surface of the case 2. The other end portion 71 is disposed by being bent into a substantially L shape from here and extending to the vicinity of the center of the upper surface 21 u through the side surface of the crown body 21 of the case 2. More specifically, the magnetic path forming plate 7 is disposed so as to follow the outer surface (side surface and upper surface) of the crown body 21 and to be embedded in the crown body 21.

The other end 71 of the magnetic path forming body 7 is the upper surface (a surface parallel to the base 20) of the crown body 21, and the magnetic pole surface 61 on the opposite side of the magnet 6 facing the core 30 of the electromagnet 3. The positions are superimposed and set in a position shape that covers the entire magnetic pole surface 61.

In the illustrated embodiment, the magnetic path forming body 7 is formed by bending a long or belt-like thin plate member into an approximately L shape. Any shape that has a linear shape, an appropriate cross-sectional shape, or a planar shape may be used as long as it can be used.
[Function and effect of magnetic path former]

By disposing the magnetic path forming body 7 configured as described above, the arm 5 swings so that the upper surface 30u of the core 30 of the electromagnet 3 is on the magnetic pole surface 60 ( If the power supply to the coil 31 is stopped (non-energized state) at a time point facing the lower side and the relative side, the electromagnet 3 does not function.

However, since the core 30 is a magnetic body, the magnetic lines of force from the magnet 6 are absorbed and aggregated, (1) from the core 30 to the base 20, (2) from the base 20 to the magnetic path forming body 7, and (3) the A magnetic path MC of a closed pool that extends from the other end side 71 of the magnetic path forming body 7 to the back yoke 50 adjacent thereto and (4) from the back yoke 50 to the magnetic pole surface 61 on the opposite side of the corresponding magnet 6 is provided. It is formed. As a result, a closed loop magnetic path MC is formed in a state where the magnetic flux from the magnet 6 is concentrated without diffusing, so that a large magnetic attraction force (magnetization force) is generated between the magnet 6 and the core 30.

This magnetizing force works effectively as a holding force that keeps the stopped state at that position, and becomes an effective energy-saving device especially for an intermittently operated actuator with a long stopped state. is there.

DESCRIPTION OF SYMBOLS 1 Actuator 2 Case 20 Base 21 Crown body 21u Upper surface (of a crown body)
22 Bearing 3 Electromagnet 30 Core 30u Upper end surface (of core)
31 Coil (Electromagnetic coil)
4 Output shaft 5 Arm 50 Back yoke 51 Recessed part (for magnet)
52 Recess (for back yoke)
53 Thin-walled part 6 Magnet 60 Magnetic pole face (relative side)
61 Magnetic pole face (on the opposite side)
7 Magnetic path forming body 70 One end 71 Other end MC Magnetic path

Claims

A case made of a non-magnetic material that secures a predetermined internal space;
An electromagnet installed in the case;
Two magnets that are opposed to each other with the opposite magnetic pole faces along the surface direction of the magnetic pole faces opposite to the magnetic pole faces of the electromagnets;
An arm that holds the magnet and swings in the plane direction of the magnetic pole surface with an air gap and the magnetic pole surface of the electromagnet;
An output shaft that axially supports the arm in the case and outputs the swing force axially;
A magnetic path forming body disposed inside or outside the case so as to form a magnetic circuit between the opposite poles of the electromagnet and the magnet in the opposed state;
A rotary actuator comprising:
The magnetic path former is
The rotary actuator according to claim 1, wherein the rotary actuator is a belt-like plate body or a linear body.
Arrangement of the magnetic path forming body,
A part of the non-magnetic material case is formed of a magnetic material to form an installation board for the electromagnet. The rotary actuator according to claim 1, wherein the rotary actuator is configured to be close to a magnetic pole surface of the magnet.
4. The rotary actuator according to claim 1, wherein a back yoke for covering the magnetic pole surface is provided on each of the opposite sides of the two magnets.