JP2019030126A - Actuator and manufacturing method of actuator - Google Patents

Abstract

To provide an actuator which has a relatively simple structure, is manufactured easily, and can obtain large thrust in a compact constitution, and a manufacturing method thereof.SOLUTION: An actuator 20 has: a toric lower yoke 1; a plurality of cylindrical pole yokes 2 provided on one surface of the lower yoke 1; at least one toric permanent magnet 3 having a plurality of hole portions 3a into which the pole yokes 2 are inserted; a toric upper yoke 4 having a plurality of hole portions 4a into which the pole yokes 2 are inserted at the same positions as the hole portions 3a of the permanent magnet 3 in a circumferential direction; a plurality of cylindrical coils 6 into which the pole yokes 2 are respectively inserted; and a pedestal base 7 supporting the coils 6.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an actuator in which a stator and a mover are combined, and a manufacturing method thereof.

  An actuator for finely moving an optical member such as a mirror or a lens is known. For example, Patent Document 1 discloses a lens actuator having a configuration in which a permanent magnet and a coil are combined.

  FIG. 6 is a cross-sectional view showing a part of the configuration of a conventional actuator 30 such as Patent Document 1. In FIG. The central portion of the actuator 30 is a cavity 31 that is indispensable for attaching a lens. The actuator 30 has a permanent magnet 34 sandwiched between an upper yoke 32 and a lower yoke 33 at the peripheral portion and a coil 35 on the inner peripheral side of the permanent magnet 34.

  In the conventional actuator 30 having such a configuration, the flow of magnetic flux can be representatively shown by a broken line arrow in FIG. Therefore, there is only one place where the magnetic flux from the permanent magnet 34 is linked to the coil 35 in this one section. Therefore, the only way to improve the thrust is to use a large permanent magnet 34 or increase the current flowing through the coil 35.

  An actuator for obtaining a large thrust is proposed in Patent Document 2. In the configuration of Patent Document 2, a plurality of pairs of actuators configured by combining a square cylindrical stator and a cylindrical movable element are arranged so as to be coupled in the vertical and horizontal directions orthogonal to the thrust direction. The stator is configured by adhering a magnet to the inner peripheral surface of a yoke inserted into the holder, and the mover is configured by winding a coil around a core disposed on the outer periphery of a cylindrical frame. Using the technique of Patent Document 2, it is possible to combine these plural pairs of actuators to provide a cavity for attaching an optical member at the center.

JP 2008-197671 A JP 2010-154649 A

  However, in the configuration as described above using the technique of Patent Document 2, first, a plurality of stators are individually manufactured, and the plurality of stators are connected and assembled in parallel, and then each stator is movable. A child is inserted and manufactured. Therefore, there is a problem that not only the structure is complicated but also the manufacturing process becomes complicated, and the cost increase cannot be avoided.

  The present invention has been made in view of such circumstances, and an actuator capable of obtaining a large thrust with a small configuration while having a relatively simple structure and being easy to manufacture, and its manufacture It aims to provide a method.

  An actuator according to the present invention includes an annular first yoke, a plurality of columnar second yokes provided on one surface of the first yoke, and a plurality of holes through which the second yoke penetrates. At least one annular permanent magnet, an annular third yoke having a plurality of holes through which the second yoke penetrates at the same position in the circumferential direction as the holes, and the first Each of the two yokes includes a plurality of cylindrical coils, and a pedestal that supports the coils.

  In the actuator of the present invention, at least one annular first yoke having a plurality of cylindrical second yokes provided on one surface, and an annular shape in which the second yoke is penetrated in the plurality of holes. A stator having a configuration in which a magnet and an annular third yoke with a second yoke penetrated are stacked and a plurality of coils with the second yoke penetrated are supported by a pedestal. Composed of a combination of children. Since the permanent magnet having a plurality of holes and a plurality of small coils are used to penetrate the coil in the hole of the permanent magnet, there are two places where the magnetic flux from the permanent magnet interlinks with the coil. Further, since the path length per location where the magnetic flux flows is also shorter than that in the conventional example, the magnetic resistance can be reduced and a larger amount of magnetic flux can be passed. As a result, the interlinkage area can be increased by a factor of 1.5 or more compared to the conventional example, so that a large thrust can be obtained even with a small configuration.

  The actuator according to the present invention is characterized in that a guide member that contacts the pedestal is provided on the third yoke.

  In the actuator of the present invention, a guide member that contacts the pedestal is provided on the third yoke. Therefore, the guide member can suppress vibrations such as flexural vibration and resonance vibration of the pedestal. As a result, even if the mover is moved at high speed, no large vibration is generated, and stable high-speed linear movement without rattling. Can be realized.

  The actuator according to the present invention is characterized in that the number of coils is equal to or less than the number of holes of the permanent magnet.

  In the actuator of the present invention, the number of coils is the same as or less than the number of holes of the permanent magnet. When the number of coils is the same as the number of holes in the permanent magnet, one coil is inserted in each hole, and the number of coils is less than the number of holes in the permanent magnet. In the case where the number of the holes is small, the coil is inserted into some of the holes, and the coil is not inserted into the remaining holes. For a kind of permanent magnet having a predetermined number of holes, the number of coils can be adjusted according to the required thrust.

  The actuator according to the present invention is characterized in that the permanent magnet is a bonded magnet.

  In the actuator of the present invention, a bonded magnet is used as a permanent magnet. Therefore, a permanent magnet having a desired shape having a plurality of holes can be easily produced.

  The actuator according to the present invention is characterized in that the bonded magnet is manufactured by additive manufacturing, compression molding, or injection molding using a 3D printer.

  In the present invention, the bonded magnet is manufactured by additive manufacturing, compression molding, or injection molding using a 3D printer. Therefore, a bonded magnet having a desired shape having a plurality of holes can be easily manufactured.

  In the actuator manufacturing method according to the present invention, the plurality of cylindrical second yokes provided on one surface of the annular first yoke is replaced with the plurality of holes of at least one annular permanent magnet, and the circular shape. A plurality of cylindrical coils are supported on a pedestal with respect to a stator that is inserted in a plurality of holes that are circumferentially located at the same position as the hole of the permanent magnet of the annular third yoke. The movable element is arranged so that the second yoke penetrates the coil so that the coil can move.

  According to the present invention, even if the configuration is small, the surface area where the magnetic flux from the permanent magnet interlinks with the coil can be increased, so that an actuator with improved thrust can be provided.

It is a perspective view which shows the actuator which concerns on this invention. It is a disassembled perspective view which shows the actuator which concerns on this invention. It is sectional drawing along the central axis of the actuator which concerns on this invention. It is sectional drawing of the center axis | shaft perpendicular direction of the actuator which concerns on this invention. It is sectional drawing of the center axis | shaft perpendicular direction of the conventional actuator. It is sectional drawing which shows a part of structure of the conventional actuator.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. 1 and 2 are a perspective view and an exploded perspective view showing an actuator according to the present invention.

  The actuator 20 of the present invention is configured by combining the stator 11 and the mover 12.

  The stator 11 has a lower yoke 1 as a first yoke, a plurality of pole yokes 2 as second yokes, two permanent magnets 3 and 3, and an upper yoke 4 as a third yoke. These members are laminated and integrated.

  The lower yoke 1 has an annular shape. A plurality (16 in this example) of columnar pole yokes 2 are erected on one surface of the inner side of the lower yoke 1 (the side facing the permanent magnet 3) in the circumferential direction of the lower yoke 1. ing. The lower yoke 1 and the pole yoke 2 are made of a soft magnetic material such as a silicon steel plate. A plurality (four in this example) of positioning pins 1a for positioning with the permanent magnet 3 are provided on the inner surface of the lower yoke 1 at equal positions in the circumferential direction.

  The two permanent magnets 3 and 3 have the same shape, and both are annular bonded magnets. The permanent magnet 3 is magnetized in the thickness direction. The permanent magnet 3 is formed with a plurality (16 in this example) of hole portions 3a equally distributed in the circumferential direction. One pole yoke 2 is inserted through each of the holes 3a. In addition, a plurality (four in this example) for positioning with the lower yoke 1 or the adjacent permanent magnet 3 are equally arranged in the circumferential direction on one surface opposite to the lower yoke 1 of the permanent magnet 3. The protruding portion 3b is formed. The circumferential position of the protrusion 3b is the same as the circumferential position of the positioning pin 1a. A concave portion (not shown) for positioning is formed at a position corresponding to the positioning pin 1a on the surface (surface on the lower yoke 1 side) opposite to the surface on which the protrusion 3b of the permanent magnet 3 is disposed.

  The permanent magnet 3 is, for example, a bond magnet (resin-bonded magnet) manufactured by additive manufacturing (3D printing) using a 3D printer using a mixture of a magnetic powder of SmFeN-based alloy and a resin as a material. is there. In 3D printing, a mixture of magnetic powder and resin is extruded and laminated from a nozzle to a stacking table while moving the nozzle and the stacking table relatively three-dimensionally to obtain a desired shape, thereby producing a bonded magnet.

  The upper yoke 4 has an annular shape. A plurality (16 in this example) of holes 4a are formed in the upper yoke 4 at equal intervals in the circumferential direction. The circumferential positions of these holes 4a are the same as the circumferential positions of the holes 3a of the permanent magnet 3, and one pole yoke 2 is inserted into each of these holes 4a. On one surface of the upper yoke 4 opposite to the permanent magnet 3, a plurality (four in this example) of columnar guide members 5 are provided at equal positions in the circumferential direction. The upper yoke 4 is made of a soft magnetic material such as a silicon steel plate. A concave portion (not shown) for positioning is formed on the surface of the upper yoke 4 facing the permanent magnet 3 at a position corresponding to the protruding portion 3b.

  The mover 12 has a plurality (16 in this example) of cylindrical coils 6 and an annular pedestal 7 that supports the coils 6. The coil 6 is provided on one surface of the pedestal 7 with, for example, an adhesive or the like. It is supported and fixed by.

  The coil 6 is configured by, for example, winding a copper wire in a cylindrical shape. A single pole yoke 2 is inserted into each coil 6 through the hole 4a of the upper yoke 4 and the holes 3a and 3a of the permanent magnets 3 and 3. Here, the coil 6 is arranged so that the inside of the hole 4a and the hole 3a can be moved in the axial direction of the actuator 20.

  The base 7 is made of a nonmagnetic material such as aluminum. A plurality (four in this example) of groove portions 7a are formed on the inner peripheral surface of the base 7 so as to be equally distributed in the circumferential direction. The circumferential position of the groove portion 7a is the same as the circumferential position of the guide member 5, and the movable element 12 moves in such a manner that the guide member 5 contacts the groove portion 7a during driving. On the other surface of the pedestal 7, a plurality (eight in this example) of screw holes 7 b for fixing a driving object such as a lens are formed. Since the center of the base 7 is hollow, a driving object such as a lens can be easily attached to the base 7 (movable element 12).

  Hereinafter, a method for manufacturing the actuator 20 according to the present invention will be described.

  The stator 11 is manufactured by laminating and integrating the lower yoke 1, the permanent magnets 3 and 3, and the upper yoke 4 having the above-described configuration in this order. The pole yoke 2 is inserted into the holes 3 a and 3 a of the permanent magnets 3 and 3 and the hole 4 a of the upper yoke 4 by stacking and integration. At this time, accurate positioning can be easily performed due to the presence of the positioning pin 1a, the protruding portion 3b, and a recess for positioning (not shown). On the other hand, the mover 12 is manufactured by bonding the plurality of coils 6 to one surface of the base 7 with an adhesive.

  Then, the stator 11 and the mover 12 are combined so that each pole yoke 2 penetrates each coil 6 in the hole 4a of the upper yoke 4 and the holes 3a, 3a of the permanent magnets 3, 3. The actuator 20 is assembled (see FIG. 1).

  In the actuator 20 of the present invention, instead of using a conventional simple annular permanent magnet, an annular permanent magnet 3 having a plurality of holes 3a is used. By combining the plurality of small coils 6, a large thrust can be obtained even with a small configuration.

  FIG. 3 is a cross-sectional view taken along the central axis of the actuator 20 according to the present invention, and the flow of magnetic flux is indicated by broken-line arrows. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  In the actuator 20 of the present invention, even when the cavity 21 is provided in the center, the flow of magnetic flux from the permanent magnet 3 is as indicated by the broken-line arrows in FIG. There are two places on the left and right in this cross section.

  Moreover, since the plurality of coils 6 are provided, the surface area where the magnetic flux interlinks with the coils can be increased as compared with the conventional example in which one coil is provided.

  4 is a cross-sectional view in the direction perpendicular to the central axis of the actuator 20 according to the present invention shown in FIG. 3, and FIG. 5 is a cross-sectional view in the direction perpendicular to the central axis of the conventional actuator 30 shown in FIG. 4 and 5, the broken line indicates the coil center line, the diagonally hatched portion indicates the permanent magnet, and the dot portion indicates the yoke. Further, in each of FIGS. 4 and 5, the flow of magnetic flux at the same position as the cross section along the central axis shown in FIGS. 3 and 6 is indicated by a solid arrow. Note that the flow of magnetic flux shows only the upper surface side, and does not show the lower surface side.

  In the conventional actuator 30 shown in FIG. 5, the length (linkage length) L1 at which the magnetic flux from the permanent magnet 34 is linked to the coil is the circumferential length of the coil center line. Here, for example, when the outer diameter and inner diameter of the conventional actuator 30 shown in FIG. 6 are 100 mm and 60 mm, respectively, and the diameter of the coil center line is 75 mm, the interlinkage length L1 is the circumference of the coil center line. The length in the direction is 75πmm.

  In the actuator 20 of the present invention shown in FIG. 4, the result of accumulating the length L2 where the magnetic flux from the permanent magnet is linked to each one coil by the number of coils is the total linkage length. Become. Here, in the same cross-sectional area as the conventional actuator 30 described above, when considering that the cross-sectional areas of the members constituting the permanent magnet and the magnetic path are the same, the diameter of the circle in which a plurality of coils are equally arranged is 80 mm. (= (100 + 60) / 2). Twelve coils having a diameter of the coil center line of 10 mm can be arranged at a pitch of 30 degrees in such an area having a diameter of 80 mm. At this time, the interlaced length L2 of each one coil is 10π mm, and therefore the total interlinkage length in the actuator 20 of the present invention is 10π × 12 = 120πmm. Therefore, in the present invention, the interlinkage length 1.6 times that of the conventional example can be realized.

  In addition, since a plurality of small coils 6 are used, the magnetic resistance of the magnetic circuit is reduced, and the magnetic flux density generated in the linkage area can be increased. It is possible to obtain a large thrust generated at a ratio (1.6 times) or more.

  From the above, in the actuator 20 of the present invention, it is possible to improve the thrust without increasing the shape and without increasing the power consumption as compared with the conventional example.

  Moreover, as shown in FIG. 3, since it can drive with a small coil within one magnetic circuit, the area of the area | region where magnetic flux passes in the air can be made small, and a leakage magnetic field can be made small. Therefore, also in this respect, the actuator 20 of the present invention contributes to improvement in thrust.

  Moreover, since the actuator 20 of the present invention has a simple configuration, the actuator 20 can be manufactured at low cost.

  In the embodiment described above, two permanent magnets 3 are used. However, the number of permanent magnets 3 is not limited to two, and may be one or three or more. What is necessary is just to determine the number of the permanent magnets 3 used according to the magnitude | size of a required thrust.

  In the embodiment described above, the number of the pole yoke 2, the hole 3a of the permanent magnet 3 and the hole 4a of the upper yoke 4 is 16, the positioning pin 1a, the protrusion 3b of the permanent magnet 3, the guide member 5 and the base 7. The number of the groove portions 7a is four and the number of the screw holes 7b of the base 7 is eight. However, these numbers are merely examples, and other numbers may be used.

  In the above-described embodiment, the number of the holes 3a of the permanent magnet 3 and the number of the coils 6 are the same (16 in this example), and the coils 6 are always inserted through the holes 3a. However, the number of the coils 6 may be smaller than the number of the holes 3a, and the hole 3a through which the coils 6 are inserted and the hole 3a through which the coils 6 are not inserted may be mixed. In this case, it suffices to adjust the number of coils 6 according to the required thrust, and wasteful power consumption can be suppressed and the weight can be reduced. Since the same permanent magnet 3 having a predetermined number of holes 3a can be used to adjust the number of coils 6 to cope with various thrusts, a plurality of types of permanent magnets 3 having different numbers of holes 3a according to the thrusts are provided. No need to prepare.

  In the embodiment described above, the guide member 5 is provided on the upper yoke 4 and the groove portion 7a is provided on the pedestal 7. However, unlike this, the guide member as described above is provided on the pedestal 7, and the upper yoke 4, A through hole may be provided in the permanent magnet 3 and the lower yoke 1 so that the guide member moves in the through hole.

  In the above-described embodiment, the positioning pin 1a is configured as a separate component from the lower yoke 1, but unlike the protrusion 3b of the permanent magnet 3, the positioning portion is different from the lower yoke 1. It is also possible to form it integrally. Further, a through hole communicating with the lower yoke 1, the permanent magnet 3, and the upper yoke 4 may be provided, and a separate positioning pin may be passed through the through hole to integrally fix these members.

  In the above-described embodiment, the movable element 12 is configured by bonding the plurality of coils 6 to the pedestal 7. However, unlike this, the plurality of coils 6 and the pedestal 7 are integrally formed with an epoxy resin or the like. The mover 12 may be configured by molding. In this case, the base 7 is made of an epoxy resin.

  In the above-described embodiment, the permanent magnet 3 (bonded magnet) is produced using a mixture obtained by mixing magnetic powder of SmFeN alloy and resin, but unlike this, ferrite magnetic powder or NdFeB alloy Magnetic powder may be used.

  In the embodiment described above, the permanent magnet 3 (bonded magnet) is manufactured by additive manufacturing using a 3D printer, but unlike this, the permanent magnet 3 (bonded magnet) is manufactured by compression molding or injection molding. You may make it do.

  The disclosed embodiments should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Lower yoke (first yoke)
1a Positioning pin 2 Pole yoke (second yoke)
3 Permanent magnet 3a Hole 3b Projection 4 Upper yoke (third yoke)
4a hole 5 guide member 6 coil 7 base 7a groove 7b screw hole 11 stator 12 mover 20 actuator 21 cavity

Claims (6)

  An annular first yoke, a plurality of cylindrical second yokes provided on one surface of the first yoke, and at least one annular shape having a plurality of holes through which the second yoke is inserted. A permanent magnet, an annular third yoke having a plurality of holes through which the second yoke penetrates at the same position in the circumferential direction as the holes of the permanent magnet, and the second yoke are respectively penetrated. An actuator comprising: a plurality of cylindrical coils, and a pedestal that supports the coils.   The actuator according to claim 1, wherein a guide member that contacts the pedestal is provided on the third yoke.   3. The actuator according to claim 1, wherein the number of the coils is equal to or less than the number of holes of the permanent magnet.   The actuator according to any one of claims 1 to 3, wherein the permanent magnet is a bonded magnet.   The actuator according to claim 4, wherein the bond magnet is manufactured by additive manufacturing using a 3D printer, compression molding, or injection molding.   A plurality of cylindrical second yokes provided on one surface of the annular first yoke, a plurality of holes of at least one annular permanent magnet, and the permanent magnet of the annular third yoke The coil can move a mover that supports a plurality of cylindrical coils on a pedestal, with respect to a stator that penetrates a plurality of holes at the same position in the circumferential direction as the hole. A method for manufacturing an actuator, wherein the second yoke is disposed so as to penetrate the coil.

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