CN117411266A - Rotary reciprocating drive actuator - Google Patents

Abstract

The invention provides a rotary reciprocating drive actuator which has high rotation precision, improves the rigidity of a shaft, and performs low-sliding and high-reliability driving. The rotary reciprocation drive actuator has: a movable body having a shaft portion to which a magnet is fixed at an outer periphery thereof, the movable body being capable of reciprocating rotation about the shaft; a base portion having a pair of wall portions rotatably supporting the shaft portion via a bearing; and a core assembly including a core body having a plurality of magnetic poles facing an outer periphery of the magnet with the magnet interposed therebetween, a coil body wound around the core body and configured to reciprocate the movable body by generating magnetic flux interacting with the magnet by energization, and a magnet position holding portion configured to generate magnetic attraction force between the movable body and the magnet, and defining a reference position for the reciprocation, the core assembly including a preload applying portion externally inserted in the shaft portion and configured to apply preload to the bearing.

Description

Rotary reciprocating drive actuator

Technical Field

The present invention relates to a rotary reciprocating drive actuator.

Background

Conventionally, as an actuator used in an optical scanning device such as a multi-functional peripheral or a laser beam printer, a rotary reciprocating drive actuator has been used. Specifically, the rotary reciprocation drive actuator reciprocates the mirror of the scanner to change the reflection angle of the laser beam, thereby realizing optical scanning of the object.

Patent document 1 discloses a technique of using a galvanometer motor as such a rotationally reciprocating drive actuator. As the galvanometer motor, various types are known in addition to the type of construction disclosed in patent document 1 and the type of coil movable in which a coil is mounted to a mirror.

Patent document 1 discloses a beam scanner in which four permanent magnets are provided on a rotation shaft to which a mirror is attached so as to be magnetized in a radial direction of the rotation shaft, and a core around which a coil is wound and having magnetic poles is disposed so as to sandwich the rotation shaft.

Prior art literature

Patent literature

Patent document 1: japanese patent No. 4727509

Disclosure of Invention

Problems to be solved by the invention

However, the beam scanner of patent document 1 rotatably supports a rotary shaft to which a mirror is attached via a bearing between a pair of wall-shaped bearing brackets that stand apart from a fixed base.

In the beam scanner having such a structure, a rotary reciprocating drive actuator is desired which improves the rotation accuracy of the rotary shaft with respect to the bearing and performs more stable rotary drive.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a rotary reciprocating drive actuator which has high rotation accuracy, improves rigidity of a shaft, and performs drive with low slip and high reliability.

Means for solving the problems

One embodiment of the rotary reciprocation drive actuator of the present invention is configured to have:

a movable body having a shaft portion to which a magnet is fixed at an outer periphery thereof, the movable body being capable of reciprocating rotation about the shaft;

a base portion having a pair of wall portions rotatably supporting the shaft portion via a bearing; and

a core assembly including a core body having a plurality of magnetic poles facing an outer periphery of the magnet with the magnet interposed therebetween, a coil body wound around the core body and configured to reciprocate the movable body by generating magnetic flux interacting with the magnet by energization, and a magnet position holding portion configured to generate magnetic attraction force with the magnet to define a reference position for the reciprocation,

the bearing is provided with a preload applying part which is externally inserted in the shaft part and applies preload to the bearing.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the rotation accuracy is high, the rigidity of the shaft is improved, and the drive with low sliding and high reliability can be performed.

Drawings

Fig. 1 is an external perspective view of a rotary reciprocation drive actuator according to embodiment 1 of the present invention.

Fig. 2 is a longitudinal sectional view of the axial center of the rotary reciprocation drive actuator.

Fig. 3 is an end view of the A-A line portion of the left component removed from the front side end face of the drive unit in fig. 2.

Fig. 4 is an exploded perspective view of the rotary reciprocation drive actuator.

Fig. 5 is a front side perspective view of the state in which the driving unit is detached from the main body unit.

Fig. 6 is a rear side perspective view of the main body unit with the drive unit removed.

Fig. 7 is a perspective view of the main body unit.

Fig. 8 is a sectional view taken along line B-B of fig. 7.

Fig. 9 is an enlarged view of the preload spring.

Fig. 10 is a diagram showing a wave spring as a modification of the preload spring.

Fig. 11 is an enlarged perspective view of the front end of the rotary reciprocation drive actuator.

Fig. 12 is a perspective view of the inside of the top cover in a state in which the sensor substrate is removed in fig. 11.

Fig. 13 is a sectional view taken along line C-C of fig. 11.

Fig. 14 is an exploded perspective view of the driving unit.

Fig. 15 is a perspective view of the coil body.

Fig. 16 is an exploded view of the bobbin.

Fig. 17 is a perspective view showing a connection state of the coil in the coil body.

Fig. 18 is a front side perspective view of the bottom cover.

Fig. 19 is a sectional view taken along line D-D of fig. 11.

Fig. 20 is a diagram for explaining the operation of the magnetic circuit of the rotary reciprocation drive actuator.

Fig. 21 is a longitudinal sectional view showing modification 1 of the rotary reciprocation drive actuator.

Fig. 22 is an exploded perspective view of modification 1 of the rotary reciprocation drive actuator.

Fig. 23 is an external perspective view of modification 2 of the rotary reciprocation drive actuator.

Fig. 24 is a perspective view of a main body unit of modification 2 of the rotary reciprocation drive actuator.

Fig. 25 is a front view showing a main part configuration of a drive unit in modification 2 of the rotary reciprocating drive actuator.

Fig. 26 is a perspective view of modification 2 of the rotary reciprocation drive actuator attached to a product.

Fig. 27 is an external perspective view of modification 3 of the rotary reciprocation drive actuator.

Fig. 28 is an external perspective view of a top cover of modification 3 of the rotary reciprocation drive actuator.

Fig. 29 is a perspective view showing modification 3 of the rotary reciprocation drive actuator attached to a product.

Fig. 30 is an external perspective view of a bottom cover of modification 4 of the rotary reciprocation drive actuator.

Fig. 31 is a perspective view showing modification 4 of the rotary reciprocation drive actuator attached to a product.

Fig. 32 is a diagram showing a main part configuration of a scanner system using a rotary reciprocation drive actuator.

Fig. 33 (a) and (B) are a front view and a right side view of modification 1 of the magnet.

Fig. 34 (a) and (B) are a front view and a right side view of modification 2 of the magnet

Fig. 35 (a) and (B) are a front view and a right side view of modification 3 of the magnet.

Fig. 36 (a) and (B) are a front view and a right side view of modification 4 of the magnet.

Fig. 37 is a diagram showing a core assembly of a rotary reciprocating drive actuator according to modification 4 having a magnet.

In the figure:

1. 1A, 1B, 1C, 1D-rotary reciprocating drive actuator, 2-main body unit, 4C, 4D-drive unit, 10A-movable body, 12-mirror portion, 13A-rotary shaft, 14-stopper portion, 15, 15A-limit part, 20-fixed body, 21A, 21B-base part, 22, 23-bearing, 30-driving part, 32, 320A, 320B-magnet, 32a, 32B, 410A, 410B-magnetic pole, 32C, 32D, 32e, 32f, 32g, 32h, magnetic pole switching part, 35, 350, spring for pre-compression (pre-compression imparting part), 37, annular receiving part, 39, bush, 40B, core assembly, 41, first core, 42, second core, 43, third core, 44, 45, coil, 46, 47, bobbin, 48, rotation angle position holding part, 49, coil body, 50D under cover, 52, cover main body, 53, 321, opening part, 54, 55, 66-through holes, 56, 526, 626-positioning holes, 57-position adjustment holes, 58-core holding protrusions, 59, 808-positioning protrusions, 60C-top cover, 62C-top cover main body, 64-peripheral wall portion, 65-sensor receiving portion, 67-pin engagement holes, 70-angle sensor portion, 72-sensor substrate, 74-encoder disk (detected portion), 76-photo sensor (sensor), 81, 84, 86, 87-fixing member, 100-laser system, 101-laser light emitting portion, 102-laser control portion, 103-driving signal supply portion, 104-position control signal calculating portion, 121-mirror, 122-mirror holder, 122a, 211Aa, 212a, 212Aa, 211Ba, 212 Ba-insertion hole, 131-one end portion, 132-the other end portion, 133A-fitting groove, 211A, 211B, 212, 212A-wall portion, 213A, 213B-bottom portion, 215, 525, 625-fixing hole, 217, 527, 627-positioning notch portion, 218-concave portion, 212A-insertion hole, 222, 232-bearing body, 224, 234-flange, 322-end face, 326-outer peripheral face, 328-flat face, 400-core body, 411a, 411B-rod-like body, 412-connecting side portion, 413A, 413B-side portion, 414-auxiliary pole portion, 414-reinforcing portion, 492-coil frame portion, 494-terminal support portion, 496-terminal, 522-mounting portion, 541, 2112, 6212-countersink portion, 621-concave portion, 726-through hole, 800-fixing table portion, 804, 806-fixing wall portion, 807-fixing hole, 2110, 5210, 6210-both side protruding side portion, 4964-other side portion, 4962-one side portion.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is an external perspective view of a rotary reciprocation drive actuator 1 according to embodiment 1 of the present invention, and fig. 2 is a longitudinal sectional view through the axis of the rotary reciprocation drive actuator 1. Fig. 3 is an end view of a line A-A of the left member removed from the front end surface in fig. 2 so that the interior of the drive unit 4 can be seen, and fig. 4 is an exploded perspective view of the rotary reciprocating drive actuator 1.

The rotary reciprocating drive actuator 1 is used, for example, in a laser radar (LiDAR: laser Imaging Detection and Ranging) device. The rotary reciprocation drive actuator 1 can be applied to an optical scanning device such as a complex machine or a laser beam printer.

The rotary reciprocation drive actuator 1 is roughly divided into a drive unit 4 including a movable body 10, a base portion 21 rotatably supporting the movable body 10, and reciprocating rotation drive of the movable body 10 with respect to the base portion 21. The base portion 21 and the driving unit 4 constitute a fixed body 20 that supports the movable body 10 so as to be rotatable in a reciprocating manner.

In the rotary reciprocating drive actuator 1, the body unit 2 is configured by attaching the movable body 10 to the base portion 21, and the rotary reciprocating drive actuator 1 includes the drive unit 4 at one end portion of the body unit 2.

Fig. 5 is a front perspective view of the main body unit 2 with the drive unit 4 removed, and fig. 6 is a rear perspective view of the main body unit 2 with the drive unit 4 removed.

As shown in fig. 5 and 6, the main body unit 2 and the driving unit 4 in which the movable body 10 is mounted on the base portion 21 are mounted by the fixing member 81. The fixing member 81 may be any member as long as it can fix both members, and for example, a screw, a male screw such as a screw, or a bolt and a nut may be used.

The movable body 10 has a rotation shaft 13, a mirror portion 12, and a movable magnet (hereinafter simply referred to as "magnet") 32. Further, details of the magnet 32 will be described in detail together with the drive unit 4 described later.

The mirror portion 12 is a movable object in the rotary reciprocation drive actuator 1, and is connected to the rotary shaft 13. The mirror portion 12 is formed by, for example, attaching a mirror 121 to one surface of a mirror holder 122. The rotation shaft 13 is inserted into and fixed to the insertion hole 122a of the mirror bracket 122. The mirror portion 12 reflects the scanning light.

Fig. 7 is a perspective view of the body unit, and fig. 8 is a sectional view taken along line B-B of fig. 7.

As shown in fig. 4 to 8, the base portion 21 includes a flat plate-like bottom portion 213 and a pair of wall portions 211 and 212 disposed apart from each other. The bottom 213 is flat plate-shaped, extends in the axial direction, and has a pair of wall portions 211 and 212 standing at opposite ends thereof. The base portion 21 is formed into a substantially コ -shaped (U-shaped) cross section by the bottom portion 213 and the pair of wall portions 211, 212.

The pair of wall portions 211, 212 are each rectangular plate-shaped, and have insertion holes 211a, 212a formed in the central portions thereof. Bearings 22 and 23 are fitted into the insertion holes 211a and 212a, and the rotary shaft 13 is inserted into the bearings 22 and 23.

Further, countersunk portions having a larger diameter than the penetrating portions are provided at the opening edges of the insertion holes 211a, 212a on the outer sides in the axial direction, respectively. The flanges 224 and 234 of the bearings 22 and 23 are fitted into the spot facing portions.

In the bearings 22 and 23, flanges 224 and 234 are provided at the opening edges of one side of the annular bearing bodies 222 and 232. The bearings 22 and 23 are fitted in the wall portions 211 and 212 of the base portion 21 from the axial outer side, and the flanges 224 and 234 are fitted in the spot facing portions. The bearings 22 and 23 are fixed to the base portion 21 in a state in which the bearings 22 and 23 are prevented from falling off in the fitting direction.

Accordingly, the wall portions 211 and 212 of the base portion 21 can be thinned without the bearing bodies 222 and 232 of the bearings 22 and 23 protruding outward from the wall portions 211 and 212 with respect to the base portion 21, and the overall length of the rotary reciprocating drive actuator 1 can be reduced.

The flanges 224 and 234 of the bearings 22 and 23 are fitted to spot facing portions on the outer sides (outer surface sides of the wall portions 211 and 212) in the axial direction of the insertion holes 211a and 212a. Thus, the fitting state of the flanges 224 and 234 with the insertion holes 211a and 212a can be easily visually checked and measured from the outside of the wall portions 211 and 212 during the assembly of the main body unit 2.

The bearings 22 and 23 may be constituted by rolling bearings (e.g., ball bearings) and sliding bearings for the base portion 21. For example, since the bearings 22 and 23 are rolling bearings having a low friction coefficient and the rotation shaft 13 can be smoothly rotated, the driving performance of the rotary reciprocating drive actuator 1 is improved. Thus, the rotation shaft 13 is rotatably attached to the base portion 21 via the bearings 22 and 23, and the mirror portion 12 as a movable object is disposed between the pair of wall portions 211 and 212.

The rotary shaft 13 is inserted through the bearings 22 and 23, and both end portions of the rotary shaft 13 protrude outward from the bearings 22 and 23 in the axial direction. The bearings 22 and 23 rotatably support the rotary shaft 13 around the shaft to the base portion 21.

A mirror portion 12 as a movable object is fastened to a portion interposed between a pair of wall portions 211, 212 of the base portion 21 on one end side of the rotation shaft 13, and a magnet 32 is fastened to the other end 132 side of the rotation shaft 13. Thus, the rotation shaft 13 is pivotally supported by the pair of wall portions 211 and 212 of the base portion 21. The base portion 21 supports the mirror portion 12 disposed between the pair of wall portions 211, 212 via the rotation shaft 13 from both sides, and therefore, can firmly support the rotation shaft and improve impact resistance and vibration resistance, as compared with a structure in which the mirror portion 12 is supported by the rotation shaft supported by the cantilever shaft.

One end portion side of the rotation shaft 13 is connected to the mirror portion (movable object) 12 between the pair of wall portions 211 and 212, and the other end portion 132 of the rotation shaft 13 is inserted into a bearing (ball bearing) 22 of one wall portion 211 of the pair of wall portions 211 and 212, and is fixed to the magnet 32 outside the one wall portion 211.

The magnet 32 is disposed in the driving unit 4 described later, and is reciprocally rotationally driven by magnetic flux generated by the driving unit 4. The rotation shaft 13 also reciprocates the mirror portion 12 by the electromagnetic interaction between the drive unit 4 and the magnet 32.

In the rotary shaft 13, a stopper (retainer ring) 14 is fitted into the fitting groove 133 at one end 131 protruding outward of the bearing 23, and movement of the rotary shaft 13 toward the other end 132 is restricted by the stopper 14.

A tubular stopper 15 is externally inserted to the rotary shaft 13 at a position between the mirror holder 122 of the mirror portion 12 and the wall 212 on the one end 131 side of the pair of wall portions.

The stopper 15 is fixed to the rotation shaft 13. The movement of the rotation shaft 13 toward the one end 131 side is regulated by the bearing 23, and the movement of the rotation shaft 13 toward the other end 132 side is regulated by the stopper 14. The movement of the mirror portion 12 fastened to the rotation shaft 13 toward the other end portion 132 side in the axial direction with respect to the base portion 21 is restricted via the stopper portion 14.

The stopper 15 prevents the rotation shaft 13 from coming off the bearing 23 toward one axial end, that is, toward the outside via the mirror 12.

The stopper 15 restricts the axial movement of the movable body 10 including the mirror 12, the rotation shaft 13, and the magnet 32 to a predetermined range including a tolerance or the like together with the stopper 14, and prevents the movable body from falling off the base 21.

The rotation shaft 13 is disposed in the base portion 21 such that the bearing 22 is inserted into the base portion 21 on the other end portion 132 side and protrudes from the wall portion 211 to the outside of the base portion 21. The portion protruding from the wall portion 211 is inserted into the driving unit 4.

The magnet 32 fastened to the other end 132 side of the rotary shaft 13 is disposed at a position protruding outward from the wall 211 of the base portion 21.

A preload spring (preload applying portion) 35, an annular receiving portion 37, and a magnet 32 are disposed in this order from the wall portion 211 side on the rotating shaft 13 at a portion protruding from the wall portion 211 toward the other end portion 132 side.

The preload spring 35 expands and contracts in the axial direction and biases the bearing 22 in the axial direction. The preload spring 35 is disposed between the bearing 22, which is a ball bearing, and the magnet 32, particularly, at one wall portion 211.

For example, as shown in fig. 9, the preload spring 35 is a cylindrical coil spring having a predetermined length L1 corresponding to a space in which the preload spring 35 is disposed, and flat surfaces are formed at both ends separated in a predetermined length direction.

The preload spring 35 is disposed so as to be inserted into the rotary shaft 13, and biases the magnet 32 in a direction away from the bearing 22 fitted to the wall 211.

The preload spring 35 is interposed between the annular receiving portion 37 adjacent to the magnet 32 and the bearing 22 with the rotary shaft 13 inserted therein.

The preload spring 35 applies a constant-pressure preload to the bearing 22. Accordingly, even when the load applied to the rotation shaft 13 varies or the rotation shaft 13 expands and contracts due to a temperature difference between the rotation shaft 13 and the base portion 21 during rotation, the load can be absorbed by the preload spring 35, and the variation in the preload of the bearing 22 can be reduced, so that a stable preload can be obtained. Accordingly, the preload spring 35 can prevent the axial vibration of the rotary shaft 13 caused by the high-speed rotation of the rotary shaft 13, and can rotationally drive the rotary shaft at a high speed as compared with the fixed-position preload, thereby preventing the axial vibration.

The preload spring 35 can stably drive the rotary shaft 13 by providing preload to the bearings (in particular, ball bearings) 22 and 23, while maintaining low slidability and high reliability of the rotary drive.

The preload spring 35 is preferably configured to abut against a member firmly fixed to receive preload by the member. The annular receiving portion 37 is a press-fit ring, and is fastened to the rotary shaft 13 by being press-fitted into an outer peripheral portion of the rotary shaft 13 with respect to the rotary shaft 13.

The annular receiving portion 37 receives one end portion of the preload spring 35 in contact with the bearing 22 on one end portion side, thereby preventing the magnet 32 as the adhesive fixing member from being directly given an impact. This prevents excessive force from being applied to the magnet 32, and can improve reliability.

Further, since the preload spring 35 is disposed inside the rotary reciprocating drive actuator 1, it is not affected from the outside of the rotary reciprocating drive actuator 1, and a stable preload design can be ensured.

Instead of a cylindrical coil spring in which a round wire is wound in a spiral shape, the preload spring 35 may be a wave spring in which a plate-shaped wire is wound in a spiral shape or a circular ring shape and a wave shape is applied as a spring in the expansion and contraction direction, that is, as a spring having a low height.

For example, as the preload spring 350 having a smaller axial length than the cylindrical coil spring having the axial length L1 of the preload spring 35, the preload spring 350 shown in fig. 10 may be used.

In the preload spring 350 as the wave spring, the length L2 in the axial direction as the expansion and contraction direction is shorter than the length L1 of the cylindrical coil spring and the length of expansion and contraction is shorter.

When the length L0 of the wall 211 and the annular receiving portion 37 corresponds to a range of the length L2 < L0 < L1, and the like, the extension and contraction lengths of the preload springs 350 can be changed by overlapping the preload springs 350 in the direction of the length L2.

In this way, the preload springs 35 and 350 can appropriately be rotated at a high speed by appropriately changing the preload according to the installation position or the preload target, and can be stably driven while preventing axial vibration.

Fig. 11 is an enlarged perspective view of the front end of the rotary reciprocation drive actuator, fig. 12 is a perspective view of the inside of the top cover showing a state in which the sensor substrate 72 is removed in fig. 11, fig. 13 is a cross-sectional view taken along line C-C of fig. 11, and fig. 14 is an exploded perspective view of the drive unit.

< drive Unit 4 >)

The driving unit 4 shown in fig. 2 to 6 and fig. 11 to 14 is provided at one of both end portions of the base portion 21 separated in the axial direction, and constitutes a part of the fixed body 20. The driving unit 4 constitutes a driving unit 30 together with the magnet 32, and moves the movable body 10. The drive unit 4 has a bottom cover 50, a core assembly 40, and a top cover 60. The driving unit 4 is formed, for example, in a rectangular parallelepiped shape having a square shape when viewed from the front.

< core Assembly 40 >)

The core assembly 40 shown in fig. 3, 4 and 14 includes coils 44 and 45, bobbins 46 and 47 around which the coils 44 and 45 are wound, a core 400, and a rotational angle position holding portion 48.

In the present embodiment, the core assembly 40 is formed in a rectangular frame-like block shape (more specifically, a rectangular parallelepiped shape) in which the magnetic poles 410a and 410b are arranged inside. The core assembly 40 is formed such that the frame-shaped outer peripheral portion surrounds the magnetic poles 410a and 410b disposed inside the outer peripheral portion. The core assembly 40 forms one magnetic path that is folded back and extended from the magnetic poles 410a, 410b of the magnet 32, respectively, and surrounds the magnetic poles 410a, 410b, for example, in a rectangular region of the wall surface of the wall portion 211 of the base portion 21 as viewed in the axial direction.

< core 400 >

The core 400 constitutes a magnetic circuit having a magnetic circuit disposed so as to surround the magnet 32. The core 400 has: a first core 41 having an integrated structure including a plurality of magnetic poles 410a, 410b and a C-shaped magnetic path portion (connecting side portion 412 and side portion 413); a second core 42 disposed so as to bridge between the side edge portions 413 of the first core 41; and a frame-shaped third core 43. The core 400 is integrated by magnetically coupling the first to third cores.

The first to third cores 41 to 43 pass magnetic fluxes generated when the coils 44 and 45 are energized through the plurality of magnetic poles 410a and 410b. The first to third cores 41 to 43 are laminated cores formed by laminating electromagnetic steel plates (laminated members) such as silicon steel plates, for example. By forming the core 400 in a laminated structure, the first to third cores 41 to 43 having a complicated shape can be formed at low cost.

< first core 41 >)

In the first core 41, the base ends of a plurality of rod-shaped bodies 411 (411 a, 411 b) each having opposite magnetic poles at the tip end are connected to a connecting edge 412 extending perpendicularly to the extending direction thereof. Two side edges 413a and 413b are respectively perpendicularly protruded from both ends of the connecting edge 412. An auxiliary pole 414 extending parallel to the rod-shaped bodies 411a and 411b is provided between the rod-shaped bodies 411a and 411b at the connecting edge 412.

The rod-shaped body 411 (411 a, 411 b), the connecting side portion 412, the side portion 413 (413 a, 413 b), and the auxiliary pole portion 414 are integrally configured, and the first core 41 has a comb-tooth shape.

The rod-shaped bodies 411a and 411b have magnetic poles disposed on side surfaces of the tip portions, respectively, and the bobbins 46 and 47 are externally inserted on the base end portions side of the outer circumferences of the rod-shaped bodies 411a and 411b. Thus, the coils 44 and 45 are arranged to wind the rod-like bodies 411a and 411b.

When the coils 44 and 45 are energized and excited, the poles at the distal ends of the rod-shaped bodies 411a and 411b have polarities corresponding to the direction of the energization. The magnetic poles are disposed opposite to the magnets 32, and each of the magnetic poles has a shape curved along the outer peripheral surface of the magnets 32. These curved shapes are arranged, for example, so as to face each other in a direction orthogonal to the extending direction of the rod-like bodies 411a, 411b.

The rod-shaped bodies 411a and 411b have, for example, external dimensions such that the bobbins 46 and 47 can be externally inserted from the distal end side. Thus, the coil formers 46 and 47 can be inserted outward from the distal end sides of the rod-shaped bodies 411a and 411b in the extending direction, that is, the distal ends of the magnetic poles 410a and 410b, and positioned so as to surround the proximal end sides of the rod-shaped bodies 411a and 411 b. The externally inserted bobbins 46, 47 are arranged between the side part 413 and the auxiliary pole part 414, respectively.

The connecting side 412 constitutes one side of the rectangular core 400, is connected to the base ends of the rod-shaped bodies 411a and 411b, and extends in a direction perpendicular to the parallel direction of the rod-shaped bodies 411a and 411 b.

The connecting edge 412 mainly connects the base end portions of the rod-shaped bodies 411a and 411b and both side edges 413a and 413b. The both side portions 413a and 413b are preferably in close contact with both end portions of the second core 42, but are disposed so as to be spaced apart from both end portions of the second core 42 by a gap therebetween.

The connecting side portion 412 and the side portions 413a and 413b are provided so as to be laminated together with the second core 42 in an axially sealed state on the third core 43.

The auxiliary pole 414 is disposed so as to face the rotation angle position holding portion 48, and when the magnet 32 attracts the rotation angle position holding portion 48, attracts the other pole of the magnet 32, and enhances the attraction state with the rotation angle position holding portion 48.

Specifically, the auxiliary pole portion 414 is made of a magnetic material, and is disposed so as to surround the magnet 32 in a square shape, for example, together with the magnetic poles 410a and 410b and the rotation angle position holding portion 48. The auxiliary pole portion 414 generates a magnetic attraction force with the magnet 32 (more specifically, the pole 32 b), and moves the pole 32b of the magnet 32 different from the pole 32a of the attraction rotation angle position holding portion 48 to an opposing position. By this action, the auxiliary pole 414 counteracts the axial load acting on the movable body 10 by the magnetic attraction force of the rotation angle position holding portion 48. Further, "counteracting the axial load" also includes "counteracting the axial load".

The auxiliary pole surface of the auxiliary pole portion 414 facing the outer peripheral surface of the magnet 32 is a curved surface corresponding to the shape of the outer peripheral surface of the magnet 32, and has a uniform gap across the entire surface between the outer peripheral surface of the magnet 32. Further, since the auxiliary pole portion 414 is disposed so as to surround the magnet 32 in the core assembly 40 together with the rotation angle position holding portion 48, the rotary reciprocating drive actuator 1 can be realized in a state of a minimum space layout, which can be further miniaturized.

< second core 42 >)

The second core 42 constitutes a magnetic circuit together with the first core 41, and the magnetic circuit is arranged so as to surround the magnetic poles of the tip ends of the rod-like bodies 411a, 411b from four directions. The second core 42 is formed in a prismatic shape, and when the coils 44 and 45 are energized, a magnetic path is formed through which magnetic fluxes pass at the magnetic poles 410a and 410 b.

The second core 42 has the same thickness (axial length) as the both side portions 413a, 413 b. The second core 42 is fixed to the bottom cover 50 and the top cover 60 in a state of being in close contact with the third core 43 via the fixing member 86 inserted into the same mounting hole (fixing hole) 402 as the mounting hole (fixing hole) 402 provided at both end portions of the connecting side portion of the first core 41 (see fig. 13). The mounting hole 402 is formed to have the same diameter as the through hole 54 of the bottom cover 50 and extend parallel to the rotation shaft 13.

A rotation angle position holding portion 48 is attached to a portion of the second core 42 that faces the magnet 32 at a central portion in the extending direction.

< third core 43 >)

The third core 43 forms a magnetic circuit surrounding and connecting the plurality of magnetic poles together with the connecting side portions 412, both side portions 413, and the second core 42 of the first core 41.

The third core 43 has a rectangular frame plate shape, and is mounted in surface contact with a rectangular frame-like portion formed by both the first core 41 and the second core 42.

Specifically, the third core 43 is in surface contact with the connecting side portion 412 and the both side portions 413a, 413b of the first core 41 in the extending direction of the rotation shaft 13. In addition, the third core 43 is assembled to the first core 41 in a state in which the plurality of magnetic poles of the rod-like bodies 411a, 411b of the first core 41 are positioned around the rotation shaft 13. In addition, the third core 43 is in face-to-face ground contact with the second core 42 in the extending direction of the rotation shaft 13.

Thus, the third core 43 is disposed around the rotation shaft 13 so as to surround the magnetic poles and coils 44 and 45 of the rod-shaped bodies 411a and 411b, and forms a seamless magnetic path around the rotation shaft 13. The first to third cores 41 to 43 have surrounding portions surrounding the coils 44 and 45, and can form a magnetic flux flow passing through the first core 41+third core 43, the third core 43+second core 42, and the third core 43+first core 41 in this order from one magnetic pole to the other magnetic pole. Further, the first to third cores 41 to 43 surround the magnetic poles and the magnets 32 between the magnetic poles in a ring shape, so that the coils 44 and 45 can be prevented from being contacted from the outside.

In the assembled state of the drive unit 4, the rotary shaft 13 is inserted into the space surrounded by the magnetic poles. The magnet 32 attached to the rotary shaft 13 is located in the space, and the magnetic pole faces the magnet 32 with the air gap G therebetween at a correct position.

The magnet 32 is a ring-shaped magnet in which the S-poles 32a and the N-poles 32b are alternately arranged in the circumferential direction. The magnet 32 is attached to the peripheral surface of the rotary shaft 13 so as to be located in a space surrounded by the magnetic poles 410a and 410b of the core 400 in a state where the rotary reciprocating drive actuator 1 is assembled. The magnet 32 is fixed to surround the outer circumference of the rotation shaft 13. When the coils 44 and 45 are energized, the first core 41, the second core 42, and the third core 43 including the rod-shaped bodies 411a and 411b are excited to generate polarities corresponding to the energizing directions at the magnetic poles 410a and 410 b. Thereby, magnetic force (attractive force and repulsive force) is generated between the magnetic poles 410a, 410b and the magnet 32.

In the present embodiment, the magnets 32 are magnetized to different polarities with a plane along the axial direction of the rotary shaft 13 as a boundary. That is, the magnet 32 is a two-pole magnet magnetized to equally divide the S-pole 32a and the N-pole 32 b. The number of poles (two in the present embodiment) of the magnet 32 is equal to the number of poles 410a, 410b of the core 400. The magnet 32 may be magnetized to have two or more poles according to the amplitude of the movement. In this case, the magnetic pole portions of the core 400 are provided corresponding to the magnetic poles of the magnet 32.

< magnet 32 >)

The magnet 32 switches polarity at boundary portions 32c, 32d (hereinafter referred to as "magnetic pole switching portions") of the S-pole 32a and the N-pole 32 b. The pole switching portions 32c and 32d are formed in a groove shape extending through the axial center at one end of the magnet 32. The magnetic pole switching portions 32c and 32d are respectively opposed to the magnetic poles 410a and 410b when the magnet 32 is held at the neutral position.

If the magnetic pole switching portions 32c and 32d are formed in a groove shape, the positional relationship of the members fixed to the rotary shaft 13 can be adjusted based on the groove at the time of assembly, maintenance, or the like of the rotary reciprocating drive actuator 1. In particular, the position of the mirror portion 12, the mounting position of the encoder of the angle sensor portion 70, and the like can be defined appropriately and accurately for the rotation shaft 13 in conjunction with the positions of the magnetic pole switching portions 32c, 32d of the magnet 32. For example, the jig is abutted against the groove in the axial direction, the protrusion is fitted into the groove, and the rotation of the rotation shaft 13 around the shaft is restricted to be fixed, and the jig is a reference position for other components attached to the rotation shaft 13. In particular, the angular adjustment of the mirror with respect to the poles of the magnet 32 requires precision, which can be performed.

In the neutral position, the magnetic pole switching portions 32c and 32d of the magnet 32 are disposed so as to face the magnetic poles 410a and 410b, whereby the drive unit 4 can generate a maximum torque, and the movable body 10 can be stably driven.

Further, by configuring the magnet 32 with a two-pole magnet, the movable object can be easily driven with high amplitude by cooperation with the core 400, and the driving performance can be improved. That is, the mirror portion 12 as a movable object can be driven at a wide angle. In the embodiment, the case where the magnet 32 has the pair of magnetic pole switching portions 32c and 32d has been described, but it may have two or more pairs of magnetic pole switching portions.

Coil body (coil and former) >

The coils 44 and 45 are wound around cylindrical bobbins 46 and 47. The coils 44 and 45 and the bobbins 46 and 47 are externally inserted into the rod-shaped bodies 411a and 411b of the first core 41, and the coils 44 and 45 are disposed so as to wind the rod-shaped bodies 411a and 411 b. Thus, the coils 44 and 45 are disposed adjacent to the magnetic poles of the tip portions of the rod-like bodies 411a and 411 b.

The winding direction of the coils 44 and 45 is set so that magnetic flux is appropriately generated from one of the plurality of magnetic poles of the first core 41 toward the other when current is supplied.

Fig. 15 is a perspective view of the coil body, fig. 16 is an exploded view of the bobbin, and fig. 17 is a perspective view showing a wiring state of the coil in the coil body.

Since the coil body of the bobbin 46 around which the coil 44 is wound and the coil bobbin 47 around which the coil 45 is wound have the same structure, the coil body of the bobbin 46 around which the coil 44 is wound will be described, and the description of the coil body of the bobbin 45 and the coil bobbin 47 will be omitted.

The coil body 49 has: a bobbin part 492 around which the coil 44 is wound; and a terminal support portion 494 that supports the terminal 496 and is provided integrally with the bobbin portion 492.

The bobbin part 492 has a through hole through which the rod-shaped body 411 (411 a, 411 b) is inserted, and a terminal support part 494 is provided so as to protrude from a flange of an opening edge part on one side of the bobbin part 492.

The terminal support 494 has a cylindrical shape, and a terminal 496 is inserted therein and holds the terminal 496.

The terminal 496 has an L-shape, and has one end portion 4962 for binding the end portion of the connection coil 44, and the base end portion of the other end portion 4964 is inserted into and supported by the terminal support portion 494, and the front end portion side of the other end portion 4964 protrudes outward from the terminal support portion 494.

The distal end portion side of the other side portion 4964 is connected to an external device that supplies power to the coil 44 or to the end portion of an adjacent coil. In the present embodiment, the terminal 496 has the extending direction of the one side portion 4962 parallel to the axial direction of the coil 44 and the extending direction of the other side portion 4964 orthogonal to the axial direction of the coil 44.

In the coil body 49, one side portion 4962 of the terminal 496 is arranged to extend in the opening direction of the opening portion of the bobbin 492, and the other side portion 4964 is arranged to extend in the extending direction of the flange of the bobbin 492.

The coil wires at both ends of the coil 44 are connected to one side 4962 via a connection portion H made of solder or the like.

In this way, the terminal 496 has an L-shape, and one side portion 4962, which is one side portion, is connected to the coil winding (the connection portion H, which is a leg), and is joined to the sensor substrate 72 via the other side portion 4964.

The terminals 496 are L-shaped, and therefore can be connected to the sensor substrate wiring side and the coil wiring side separately, and in particular, the operation of forming the wiring portion (leg) H connecting the coil windings by solder can be performed easily without interference of the solder and the windings.

That is, even when the wiring operation of the sensor substrate 72 and the operation of fixing the windings of the same terminal 496 are performed, the wiring operation of the substrate is not hindered by adhesion of solder or the like at the time of conducting the windings. By disposing the sensor substrate 72 in the axial direction with respect to the driving unit 4, the wiring between the sensor substrate 72 and the terminal 496 can be positioned and contaminated, and the optical sensor can be easily disposed perpendicular to the axial direction.

< rotation angle position holding portion (magnet position holding portion) 48 >)

The rotational angle position holding portion 48 shown in fig. 2 to 4 is assembled to the core assembly 40 so as to face the magnet 32 through the air gap G in a state where the rotary reciprocating drive actuator 1 is assembled. The rotation angle position holding portion 48 is attached to the second core 42 in a posture in which magnetic poles face the magnet 32, for example.

The rotation angle position holding portion 48 uses, for example, a magnet having a magnetic pole facing the magnet 32, and generates magnetic attraction force with the magnet 32 to attract the magnet 32. That is, the rotation angle position holding portion 48 forms a magnetic spring together with the rod-like bodies 411a, 411b between the magnet 32. The magnetic spring maintains the rotational angular position of the magnet 32, that is, the rotational angular position of the rotary shaft 13, at the neutral position in the normal state (when not energized) in which the coils 44 and 45 are not energized.

At this time, the magnetic pole 32b (N pole shown in fig. 3) on the opposite side of the magnetic pole 32a (S pole in fig. 3) of the magnet 32 that attracts each other with the rotation angle position holding portion 48 attracts the auxiliary pole portion 414 of the first core 41 as the approaching magnetic body. Thus, the magnet 32, that is, the mirror portion 12 as the movable object is more effectively held at the neutral position.

The neutral position is a reference position for the reciprocating rotation operation of the magnet 32, that is, a center position of the reciprocating rotation (oscillation), and is a position that becomes the same rotation angle when rotating around the axis left and right during the reciprocating rotation. When the magnet 32 is held at the neutral position, the boundary portions 32c, 32d of the magnet 32 are opposed to the poles of the rod-like bodies 411a, 411 b.

The mounting posture of the mirror portion 12 is adjusted based on the state where the magnet 32 is located at the neutral position. The rotation angle position holding portion 48 may be made of a magnetic material that generates a magnetic attraction force with the magnet 32.

Bottom cover 50 and top cover 60 >

The bottom cover 50 and the top cover 60 shown in fig. 1, 2, 4 to 6, and 11 to 14 are preferably made of a conductive material having non-magnetism and high electrical conductivity, and function as electromagnetic shields.

The bottom cover 50 and the top cover 60 are disposed on both sides of the core assembly 40 in the axial direction (thickness direction), respectively.

The bottom cover 50 and the top cover 60 can suppress the noise from being emitted to the core assembly 40 and the noise from being emitted to the outside from the core 400.

The bottom cover 50 and the top cover 60 are formed of a material having high conductivity and high thermal conductivity, for example, which is non-magnetic such as aluminum alloy. The aluminum alloy has a high degree of freedom in design, and can easily impart desired rigidity. Therefore, if the bottom cover 50 and the top cover 60 are made of an aluminum alloy, the top cover 60 is preferably made to function as a support body for supporting the rotary shaft 13.

Fig. 18 is a front side perspective view of the bottom cover. Fig. 19 is a sectional view taken along line D-D of fig. 11.

The under cover 50 is mounted on the outer surface of the wall 211 so as to overlap. The bottom cover 50 is formed in a rectangular plate shape corresponding to the outer shape of the wall 211. The bottom cover 50 has a rectangular plate-shaped cover main body 52, and an opening 53 through which the rotation shaft 13 is inserted is formed in a central portion of the cover main body 52. The opening 53 is disposed at a position facing the bearing 22, and the inner diameter of the opening 53 is larger than the outer diameter of the magnet 32. The bottom cover 50 can insert the rotary shaft 13 to which the magnet 32 is attached into the opening 53, and insert the magnet 32 into the core assembly 40.

The rotary shaft 13 is inserted into the opening 53, and a preload spring 35 (see fig. 2) externally inserted to the rotary shaft 13 is disposed.

The cover main body 52 of the bottom cover 50 is provided with a through hole 54, a through hole 55 for fixing to the base portion 21, a positioning hole 56, a position adjustment hole 57, and a core holding protrusion 58. The fixing member 86 that integrates the bottom cover 50, the core assembly 40, and the top cover 60 together into the driving unit 4 is inserted into the through hole 54. The through hole 55 is formed in the mounting portion 522 mounted to the wall portion 211. The attachment portion 522 is formed in the cover main body 52 as left and right side portions separated in a direction orthogonal to the axial direction, and includes four corner portions of the cover main body 52. Through holes 55 are formed in the corners, respectively.

The opening 53, the through holes 54, 55, the positioning hole 56, and the position adjustment hole 57 are formed parallel to the axial direction of the rotary shaft 13. The fixing members 81 and 86 are inserted into the through holes 54 and 55, so that the assembly of the base portion 21, the assembly of the drive unit 4, and even the assembly of the rotary reciprocating drive actuator 1 can be performed in the axial direction.

As shown in fig. 13, the through hole 54 has a recessed countersink 541 formed in the back surface of the cover body 52, and the countersink 541 accommodates the head of the fixing member 86 such as a screw.

The core holding projection 58 protrudes in the axial direction from the cover main body 52 at a position across the opening 53, and is fitted into the core assembly 40 and positioned when combined with the core assembly 40.

The core holding protrusions 58 are interposed between the rod-shaped bodies 411a and 411b and the side portions 413a and 413b, and prevent leakage of magnetic flux flowing between the both.

As shown in fig. 6, a positioning projection 59 is provided on the back surface of the bottom cover 50. When the bottom cover 50 and the base portion 21 are brought into contact with each other with their centers aligned with each other, the positioning projection 59 engages with the recess 218 of the wall portion 211 and is positioned.

The positioning projection 59 is, for example, an annular projection. On the other hand, as shown in fig. 5, 7 and 8, the recess 218 of the wall 211 is an annular groove formed in the base 21 so as to surround the insertion hole 211 a. The positioning projection 59 engages with the recess 218 of the annular groove, and both the wall 212 and the driving unit 4 are positioned.

The top cover 60 and the bottom cover 50 sandwich the core assembly 40 from both axial sides, and are integrally fixed by fixing members 86, thereby constituting the driving unit 4. As shown in fig. 2, 4, and 12, the top cover 60 of the present embodiment functions as a sensor housing section that houses the photosensor 76 that detects the rotation angle of the movable body 10, that is, the rotation shaft 13.

The top cover 60 has: a top cover main body 62 covering a front end side surface of the core assembly 40; and a sensor peripheral wall portion (peripheral wall portion) 64 protruding from the outer peripheral edge portion of the top cover main body 62 toward the other end portion 132 side in the axial direction to form a concave sensor housing portion 65.

The top cover main body 62 is a plate-like body having a square shape as viewed from the axial direction and having a concave portion 621 opening toward the core assembly 40 side. The top cover main body 62 and the top cover main body 62 are square plate-shaped bodies, and the peripheral wall portion 64 is formed in a rectangular frame shape rising from the outer peripheral portion of the top cover main body 62.

The top cover body 62 of the top cover 60 is provided with a through hole 66. The through hole 66 is disposed in the top cover main body 62 so as to be coaxial with the opening 53 of the bottom cover 50 and the bearings 22 and 23 of the base portion 21. A bushing 39 through which the rotation shaft 13 is inserted is fitted into the through hole 66 from the back side (one end 131 side). Thereby, the bush 39 is attached to the top cover main body 62 in a state in which the movement direction is restricted. The bushing 39 and the rotary shaft 13 may be disposed so as to slide with each other or may be disposed with a gap therebetween.

When the rotation shaft 13 receives an impact, the bush 39 prevents the impact from being transmitted to the sensor member (encoder disk) on the other end portion 132 side. The bushing 39 is attached to the top cover 60 such that the other end portion is fitted into the through hole 66 and one end portion is positioned in the concave portion 621.

The top cover main body 62 is provided with a bobbin engaging hole 67 penetrating in the axial direction in addition to the through hole 66, and engaging with the bobbins 46 and 47.

The terminal support 494 of the coil body 49 having the bobbins 46, 47 is fitted into the bobbin engaging hole 67. Thus, the terminal support portion 494 is inserted into the top cover main body 62, and the other side portion 4964 is arranged so as to protrude from the terminal support portion 494.

The engagement of the bobbin engagement hole 67 with the terminal support portion 494 also functions as positioning when the core assembly 40 and the top cover 60 are assembled.

< Angle sensor portion 70 >)

An angle sensor portion 70 is attached to the top cover 60. The angle sensor unit 70 detects the rotation angle of the movable body 10 including the magnet 32 and the rotation shaft 13. The rotary reciprocation drive actuator 1 can control the rotational angle position and rotational speed of the movable body, specifically, the mirror portion 12 as the movable object at the time of driving, via the control portion based on the detection result of the angle sensor portion 70.

The angle sensor 70 may be a magnetic or optical sensor. In the present embodiment, the angle sensor unit 70 includes a sensor substrate 72, an encoder disk 74 which is housed in the sensor housing unit 65 and constitutes the angle sensor unit 70, and a photosensor (sensor) 76 including a light source, a light receiving element, and the like.

The angle sensor portion 70 detects the rotation angle of the rotation shaft 13, and even the mirror portion 12. The encoder disk 74 is fixed to the other end 132 side of the rotation shaft 13 in the sensor housing portion 65, and rotates integrally with the magnet 32 and the mirror portion 12. That is, the rotational position of the encoder disk 74 is the same as the rotational position of the rotary shaft 13.

The light sensor 76 emits light to the encoder disk 74, and detects the rotational position (angle) of the encoder disk based on the reflected light. Thereby, the rotational positions of the magnet 32 and the mirror portion 12 can be detected.

The optical sensor 76 is mounted on the sensor substrate 72, and the sensor substrate 72 is disposed so as to close the peripheral wall portion 64, thereby closing the sensor housing portion 65.

The sensor substrate 72 is a substrate on which a photosensor 76 for detecting the rotation angle of the rotation shaft 13 is mounted. The sensor substrate 72 is disposed so that the light sensor 76 faces the magnet 32 side and covers the core assembly 40 from the other end 132 side.

The sensor board 72 has a fixing hole 722 and a through hole 726, in addition to an opening 724 provided in the center portion for inserting a mounting portion (encoder hub) for mounting the encoder disk and the rotation shaft 13.

The sensor substrate 72 is fixed to the top cover 60 via a fixing member 84. The fixing hole provided in the top cover 60 is formed in the extension of the fixing hole 402 of the core assembly 40, and has the same diameter as the fixing hole on the same axis. That is, the sensor substrate 72 is fixed to a fixing hole (fixing hole) of the same diameter, which is continuous with the mounting hole (fixing hole) 402 of the core assembly 40, on the core assembly 40 side via the fixing member 84.

In this way, the sensor substrate 72, the top cover 60, the core assembly 40 (the core 400), and the bottom cover 50 are fixed by the fixing member via the fixing holes, the mounting holes 402, the through holes 54, and the like, which are continuous in the axial direction and have the same diameter.

The sensor board 72 is provided with a circuit for detecting the rotational position (angle) of the encoder disk, and a circuit for supplying electric power to the coils 44 and 45.

As a circuit for supplying electric power, a circuit for connecting one end portions of the coils 44 and 45 to each other is included, and the circuit has a through hole 726 provided in the other end portion 4964 of the terminal support portion 494 of the bobbin having the coils 44 and 45, and connected to the circuit by being inserted.

By inserting the other side portions 4964 into the through holes 726, respectively, the coils 44, 45 are connected to each other at one end portions via the sensor substrate 72, and a circuit for inputting/outputting power supply is connected to the other end portions.

Accordingly, by simply assembling the driving unit 4 and attaching the sensor substrate 72 to the top cover 60, a circuit for supplying electric power to the coils 44 and 45 can be configured, and an excessive object such as a foreign matter from the outside can be prevented from entering the sensing portion of the angle sensor portion 70.

Further, since the other side portion 4964 of the terminal support portion 494 in the coil body is directly connected to the sensor substrate 72, the terminals of the sensor portion and the drive actuator (motor portion) can be concentrated to the sensor substrate 72 wiring as one substrate. That is, the circuit for driving the actuator is mounted on the substrate used for rotationally reciprocating the actuator 1 in addition to the circuit for the sensor, so that the substrate can be shared, and the connector for connecting the actuator itself to an external device can be unified.

The operation of the rotary reciprocation drive actuator 1 will be described below with reference to fig. 3 and 20. Fig. 20 is a diagram for explaining the operation of the magnetic circuit of the rotary reciprocation drive actuator 1.

The magnetic poles 410a, 410b of the two rod-shaped bodies 411a, 411b of the core 400 of the core assembly 40 are arranged so as to sandwich the magnet 32 with an air gap G interposed therebetween. As shown in fig. 3, when the coils 44 and 45 are not energized, the magnet 32 is held at the neutral position by the magnetic attraction force with the rotation angle position holding portion 48.

In this neutral position, one of the S-pole 32a and the N-pole 32b of the magnet 32 (the S-pole 32a in fig. 20) is attracted to the rotation angle position holding portion 48 (refer to the magnetic spring torque FM of fig. 20). At this time, the magnetic pole switching portions 32c, 32d face the center positions of the magnetic poles 410a, 410b of the core 400. The auxiliary pole 414 attracts the other of the S pole 32a and the N pole 32b of the magnet 32 (the N pole 32b in fig. 20). Thereby, the magnet 32 moves to the neutral position more effectively.

When the coils 44 and 45 are energized, the core 400 is excited, and a polarity corresponding to the energizing direction is generated in the magnetic poles 410a and 410 b. For example, when the coils 44 and 45 are energized as shown in fig. 20, magnetic flux is generated inside the core 400, and the magnetic pole 410a becomes an N pole and the magnetic pole 410b becomes an S pole.

Thus, the magnetic pole 410a magnetized to the N pole attracts the S pole 32a of the magnet 32, and the magnetic pole 410b magnetized to the S pole attracts the N pole 32b of the magnet 32. Then, the magnet 32 generates a torque in the F direction around the rotation shaft 13, and the magnet 32 rotates in the F direction. Along with this, the rotation shaft 13 also rotates in the F direction, and the mirror portion 12 fixed to the rotation shaft 13 also rotates in the F direction.

When the coils 44 and 45 are energized in the opposite directions, the magnetic flux generated in the core 400 flows in the opposite direction to the direction shown in fig. 20, and the magnetic pole 410a becomes the S pole and the magnetic pole 410b becomes the N pole. The magnetic pole 410a magnetized to the S-pole attracts the N-pole 32b of the magnet 32, and the magnetic pole 410b magnetized to the N-pole attracts the S-pole 32a of the magnet 32. Then, the magnet 32 generates a torque-F in a direction opposite to the F direction about the rotation shaft 13, and the magnet 32 rotates in the-F direction. Accordingly, the rotation shaft 13 also rotates, and the mirror portion 12 fixed to the rotation shaft 13 also rotates in the direction opposite to the direction shown in fig. 20.

The rotary reciprocation drive actuator 1 repeats the above operation to rotationally reciprocate the mirror portion 12.

In practice, the rotary reciprocating drive actuator 1 is driven by an ac wave input to the coils 44 and 45 from a power supply unit (for example, a drive signal supply unit 103 corresponding to fig. 32). That is, the energization directions of the coils 44, 45 are periodically switched. When the current flow direction is switched, the magnet 32 is biased to return to the neutral position by the magnetic attraction force between the rotation angle position holding portion 48 and the magnet 32, that is, the restoring force of the magnetic spring (the magnetic spring torque FM shown in fig. 20 and "-FM" which is the torque in the opposite direction). Thus, the movable body 10 is alternately acted with a torque in the F direction and a torque in the opposite direction (F direction) to the F direction around the shaft. Thereby, the movable body 10 is rotationally driven to reciprocate.

The driving principle of the rotary reciprocation drive actuator 1 will be briefly described below. In the rotary reciprocating drive actuator 1 of the present embodiment, the moment of inertia of the movable body (movable body 10) is J [ kg·m ] ² ]The spring constant in the torsion direction of the magnetic springs (the magnetic poles 410a, 410b, the rotation angle position holding portion 48, and the magnet 32) is set to K _sp [N·m/rad]In the case of (2), the movable body is at the resonance frequency Fr [ Hz ] calculated by the formula (1) with respect to the fixed body (fixed body 20)]Vibration (reciprocating rotation).

[ 1]

Fr: resonant frequency [ Hz ]

J: moment of inertia [ kg.m ] ² ]

K _sp : spring constant [ N.m/rad ]]

Since the movable body constitutes a mass portion in the vibration model of the spring-mass system, when an ac wave having a frequency equal to the resonance frequency Fr of the movable body is input to the coils 44 and 45, the movable body is in a resonance state. That is, by inputting an ac wave of a frequency substantially equal to the resonance frequency Fr of the movable body from the power supply unit to the coils 44, 45, the movable body can be vibrated efficiently.

The following shows equations of motion and equations of circuit that represent the driving principle of the rotary reciprocation drive actuator 1. The rotary reciprocation drive actuator 1 is driven based on a motion equation shown in the formula (2) and a circuit equation shown in the formula (3).

[ 2]

J: moment of inertia [ kg.m ] ² ]

θ (t): angle [ rad ]

K _t : torque constant [ N.m/A ]]

i (t): current [ A ]

K _sp : spring constant [ N.m/rad ]]

D: attenuation coefficient [ N.m/(rad/s) ]

T _Loss : load torque [ N.m ]]

[ 3]

e (t): voltage [ V ]

R: resistor [ omega ]

L: inductance (H)

K _e : back emf constant [ V/(rad/s)]

That is, the moment of inertia J [ kg.m ] of the movable body of the rotary reciprocating drive actuator 1 ² ]Rotation angle θ (t) [ rad ]]Torque constant Kt [ N.m/A ]]Current i (t) [ A ]]Spring constant Ksp [ N.m/rad ]]Attenuation coefficient D [ N.m/(rad/s)]Load torque TLoss [ N.m ]]And the like can be appropriately changed within a range satisfying the formula (2). In addition, the voltage e (t) [ V]Resistance R [ omega ]]Inductance L [ H ]]Back electromotive force constant KeV/(rad/s)]The amount of the compound (c) can be appropriately changed within a range satisfying the expression (3).

In this way, the rotary reciprocation drive actuator 1 is driven by the inertia moment J of the movable body and the spring constant K of the magnetic spring _sp When the coil is energized by an alternating current wave corresponding to the determined resonance frequency Fr, a high-efficiency and high-vibration can be obtainedAnd (5) dynamic output.

Modification 1 >

Fig. 21 is a longitudinal sectional view showing modification 1 of the rotary reciprocation drive actuator, and fig. 22 is an exploded perspective view of modification 1 of the rotary reciprocation drive actuator.

In the rotary reciprocation drive actuator 1A of modification 1, the orientation of the bearings 22 and 23 attached to the base portion 21A and the positions of the preload spring 35, the stopper portion 15A, and the stopper portion 14 are different from those of the rotary reciprocation drive actuator 1, and the other configurations are the same. Therefore, the same names having the same functions are given the same reference numerals, and the description thereof is omitted, and only the differences are described.

In the rotary reciprocation drive actuator 1A, the movable body 10A is attached to the base portion 21A to constitute a main body unit a, and the rotary reciprocation drive actuator 1A includes the drive unit 4 in a wall portion 211 which is one end portion of the main body unit 2.

The rotary reciprocation drive actuator 1A is compared with the rotary reciprocation drive actuator 1, and a preload spring 35 is disposed between the bearing 22 and the mirror holder 122.

The base portion 21A has bearings 22 and 23 disposed axially inward at respective central portions of a pair of wall portions 211A and 212A provided so as to stand from both end portions of the bottom portion 213 separated in the extending direction, and the bearings 22 and 23 have flanges. For example, the bearings 22 and 23 are press-fitted from the inner side in the axial direction and fitted into the insertion holes 211Aa and 212Aa. The rotary shaft 13 is inserted into the bearings 22 and 23.

The stopper 15A is shorter than the stopper 15, and is attached to the base end portion of the rotary shaft 13 from the outside of the base 21A.

The stopper 14 is fitted into the fitting groove 133A inside the wall 212 at the end of the rotation shaft 13A inserted into the wall 212A.

In this configuration, when a load is applied to the rotation shaft 13A from the axial outside of the stopper 15A, in other words, from the base end portion (one end portion 131) side of the rotation shaft 13A, the position of the rotation shaft 13A is held by the stopper 15A. In addition, even when the force of the preload spring 35 is applied, the stopper 14 maintains the position, and the same function as the preload spring 35 in the rotary reciprocating drive actuator 1 can be obtained, and the same effect can be obtained.

That is, the movable body 10A is configured such that outward preload is applied to both sides in the axial direction, and the preload spring 35 is disposed in the vicinity of the movable object. Accordingly, since the preload spring 35 is disposed in the dead zone of the rotary shaft 13 that is bridged between the pair of wall portions (both side wall portions) 211A, 212A of the base portion 21A, the back can be reduced and the size can be reduced as compared with a configuration in which the preload spring 35 is disposed in the driving unit 4.

Modification 2 >

Fig. 23 is an external perspective view of modification 2 of the rotary reciprocation drive actuator, and fig. 24 is a perspective view of a main body unit of modification 2 of the rotary reciprocation drive actuator. Fig. 25 is a front view showing a main part configuration of a driving unit in modification 2 of the rotary reciprocating drive actuator, and fig. 26 is a perspective view of modification 2 of the rotary reciprocating drive actuator attached to a product.

The rotary reciprocation drive actuator 1B shown in fig. 23 to 26 has the same function as the rotary reciprocation drive actuator 1, and has a fixing hole 215 as an actuator fixing portion fixed to a fixing stage portion 800 of a main body of a product.

The fixing hole 215 is provided in, for example, a wall portion 211B of the base portion 21B in the fixing body 20B having substantially the same function as the fixing body 20. The fixing hole 215 is formed in the flange-shaped both side flanges 2110 extending in the direction orthogonal to the axial direction from the portion where the driving unit 4 is fixed in the wall portion 211B. The fixing hole 215 may be provided in one side flange portion of the both side flange portions 2110.

The side flanges 2110 are arranged adjacent to each other on the left and right of the drive unit 4 when viewed from the front. The side flanges 2110 are disposed on the outer sides of the two sides (left and right outer sides in front view) of the attachment portion 522 attached to the wall portion 211B via the fixing member 81 in the under cover 50 of the drive unit 4.

On the back surface side of the both side protruding edge portions 2110, a spot facing portion 2112 is provided around the fixing hole 215, and the head portion of the fixing member 87 is formed so as not to protrude in the axial direction of the wall portion 211B.

The wall portion 211B has a positioning notch portion 217 and a positioning hole 216 that enable positioning when the drive unit 4 is attached to a case (for example, the fixed stage portion 800) of a product. The positioning notch 217 is provided at the outer edge of the wall 211B, for example, at the center of one of the side flanges 2110. In the wall portion 211B, a positioning hole 216 is formed at a position symmetrical to the positioning notch 217 about the center portion.

When the rotary reciprocation drive actuator 1B is attached to the main body of the product, the rotary reciprocation drive actuator 1B is fixed to a fixed stage 800 provided on the main body side (for example, as a part of the main body).

The fixing base 800 is formed in a U-shape having fixing wall portions 804 and 806 which stand apart from each other. The rotary reciprocation drive actuator 1B is fixed to the fixed base 800 so that the drive unit 4 is positioned inside the U-shape. The standing direction and the axial direction of the fixing base 800 are made parallel, the two side flanges 2110 of the wall 211B are made to abut against the upper end surfaces of the fixing wall portions 804, 806, and the rotary reciprocating drive actuator 1B is fixed by the fixing member 87 inserted through the fixing hole 215. Further, the upper end surfaces of the fixing wall portions 804 and 806 are provided with positioning projections 808 inserted into the positioning holes 216, in addition to the fixing holes 807 into which the fixing members 87 are inserted.

When the rotary reciprocating drive actuator 1B is mounted on the fixed base portion 800, the positioning projections 808 parallel to the axis are inserted into the positioning holes 216 parallel to the axis, and rotated about the axis, and the positions of both are adjusted. The fixing member 87 can be inserted and fixed to both of the fixing holes 215 and 807 by inserting a rod or the like into the positioning notch 217 and further adjusting the position.

Since the axial direction is the same direction as the axial direction of the bearing 22 due to the position of the mirror portion 12, the rotary reciprocating drive actuator 1B can be positioned and fixed to the fixed stage portion 800 with good accuracy.

The positioning notch 217, the positioning hole 216, and the fixing hole 215 are provided in the wall 211B holding the mirror portion 12. These are used to fix the wall portion 211B to the fixing base portion 800. An insertion hole (insertion hole) 211a (coaxial with the insertion hole 212 a) of a bearing (bearing) 22 of the rotation shaft 13 to which the mirror holder 122 is fixed, which is caused by the mirror position, is formed in the wall portion 211B. This allows positioning and fixing to the fixing base 80 with the same processing surface as the insertion hole 211a for determining the position of the mirror, and thus can be fixed with high accuracy.

If the actuator fixing portion is provided on the drive unit 4 side, the actuator fixing portion can be fixed to the main body of the product, that is, the fixing base portion 800, in the vicinity of the center of gravity of the rotary reciprocation drive actuator, and disturbance vibration or shock can be effectively suppressed. The actuator fixing portion may be provided in the top cover of the driving unit 4.

Modification 3 >

Fig. 27 is an external perspective view of modification 3 of the rotary reciprocation drive actuator, and fig. 28 is an external perspective view of the top cover of modification 3 of the rotary reciprocation drive actuator. Fig. 29 is a perspective view showing modification 3 of the rotary reciprocation drive actuator attached to a product.

The rotary reciprocation drive actuator 1C of modification 3 shown in fig. 27 and 28 is different from the rotary reciprocation drive actuator 1 in only the top cover 60C and has the same configuration as the other components. Therefore, the same components as those of the rotary reciprocating drive actuator 1 are denoted by the same reference numerals, and description thereof is omitted.

The rotary reciprocation drive actuator 1C shown in fig. 27 and 28 has a top cover 60C, and the top cover 60C is provided with a fixing hole 625 as an actuator fixing portion.

The rectangular plate-like top cover main body 62C of the top cover 60C is provided with two side protruding portions 6210, which protrude in a direction orthogonal to the axial direction, similarly to the wall portion 211B of modification 2. A fixing hole 625 extending parallel to the axial direction is provided in the both side flange portions 6210. The top cover 60C has a concave sensor housing portion 65 on the front side and a concave portion on the rear side, similar to the top cover 60, and functions similar to the sensor housing portion and the concave portion of the top cover 60, respectively.

Spot facing portions 6212 which are shaped to cut the periphery of the fixing hole 625 are provided continuously to the fixing hole 625 on the back surface side of the side flange portions 6210 of the top cover main body 62C. With the spot facing portion 6212, the head portion of the fixing member 87 (see fig. 29) inserted into the driving unit 4C does not protrude in the axial direction of the wall portion 211B. The through hole 66 and the bobbin engagement hole 67 are provided in the sensor housing portion 65, and the sensor housing portion 65 is covered with the sensor substrate 72.

The top cover main body 62C is provided with a positioning hole 626 and a positioning notch 627 having the same function as the wall 211B. The positioning notch 627 is provided at the center of the outer edge, for example, one of the side flanges 6210. The top cover main body 62C has a positioning hole 626 formed at a position symmetrical to the positioning notch 627 about the center portion.

In the rotary reciprocating drive actuator 1C, a fixing hole 625 as an actuator fixing portion is provided in the top cover 60C of the drive unit 4C. As a result, as shown in fig. 29, the rotary reciprocating drive actuator 1C is fastened by inserting the fixing member 87 into the fixing hole 625 and the fixing hole 807 in parallel with the axial direction, and is fixed to the pair of fixing wall portions 804 and 806 of the concave portion in the fixing base portion 800. At this time, since the top cover 60C is fixed to the fixed base 800, the driving unit 4C can be easily fixed with good accuracy without being inserted between the fixed wall portions 804 and 806.

Further, since the driving unit 4C is fixed to the fixed stage 800, the rotary reciprocating drive actuator 1C is fixed to the fixed stage 800 at a position close to the center of gravity thereof, and thus, disturbance vibration and impact can be effectively damped.

The top cover 60C is provided with a positioning hole 626 and a positioning notch 627 penetrating in the axial direction. By inserting the positioning protrusion 808 on the upper end surface of the fixing wall portion 806 into the positioning hole 626 and inserting another positioning protrusion into the positioning notch portion 627, both can be positioned before fixing both.

In addition, when the rotary reciprocating drive actuator 1C is mounted on the fixed base portion 800, the positioning protrusion 808 parallel to the axis can be inserted into the positioning hole 626 parallel to the axis. Further, by rotating the rotary reciprocation drive actuator 1C around this, and the like, the positions of the rotary reciprocation drive actuator 1C and the fixed base portion 800 are adjusted, and by inserting a rod or the like into the positioning notch portion 627, the position adjustment can be performed more accurately.

Modification 4 >

Fig. 30 is an external perspective view of a bottom cover of modification 4 of the rotary reciprocating drive actuator, and fig. 31 is a perspective view of modification 4 of the rotary reciprocating drive actuator attached to a product.

The rotary reciprocation drive actuator 1D of modification 4 has a fixing hole 525 as an actuator fixing portion provided in the bottom cover 50D of the drive unit 4. The rotary reciprocation drive actuator 1D is different from the rotary reciprocation drive actuator 1 in only the structure of the bottom cover 50D, and other components are the same. Therefore, only the differences will be described, and the same components will be denoted by the same reference numerals and the description thereof will be omitted.

As shown in fig. 30, the bottom cover 50D has, like the bottom cover 50, a rectangular plate-like cover body 52 having an opening 53 in the center, and two protruding side flange portions 5210 extending on both sides in the direction orthogonal to the axial direction, like the wall portion 211B of modification 2.

The side flanges 5210 are portions that extend outward from the drive unit 4, and have fixing holes 525 that extend parallel to the axial direction. The bottom cover 50D is provided with a positioning projection (not shown) protruding from the back surface of the bottom cover 50D, similarly to the bottom cover 50. The positioning projection engages with the recess 218 of the wall 211 of the base portion 21 to be positioned.

As shown in fig. 31, the rotary reciprocation drive actuator 1D having the bottom cover 50D is fixed to the pair of fixing wall portions 804, 806 of the concave portion in the fixing base portion 800 by inserting the fixing member 87 into the fixing hole 525 and the fixing hole 807 in parallel with the axial direction and fastening.

At this time, since the bottom cover 50D is fixed to the fixing base 800, the top cover 60 and the core assembly 40 of the driving unit 4C can be easily and accurately fixed in a state of being disposed between the fixing wall portions 804 and 806 and being shortened in the axial direction.

Further, since the driving unit 4D is fixed to the fixed stage 800, the rotary reciprocating drive actuator 1D is fixed to the fixed stage 800 at a position close to the center of gravity thereof, and thus the disturbance vibration and impact can be effectively damped.

In particular, the rotary reciprocating drive actuator 1D is fixed to the fixed stage 800 via the bottom cover 50D disposed between the core assembly 40 and the mirror portion 12. Thus, the center of gravity between the core assembly 40 and the mirror portion 12 is fixed to the fixed stage portion 800, and thus stable holding can be performed.

The bottom cover 50D is provided with a positioning hole 526 and a positioning notch 527 penetrating in the axial direction. Thereby, the positioning protrusion 808 on the upper end surface of the fixing wall portion 806 can be inserted into the positioning hole 526, and the other positioning protrusion 808 can be inserted into the positioning notch portion 527. In this way, both can be accurately positioned before being fixed via the fixing holes 807 and 525.

When the rotary reciprocating drive actuator 1D is mounted on the fixed base portion 800, the positioning projections 808 parallel to the axis are inserted into the positioning holes 216 parallel to the axis, and the positions of both can be adjusted by rotating the positioning projections around the axis, for example. Further, by inserting a rod or the like into the positioning notch 217, the position can be adjusted more accurately.

Fig. 32 is a block diagram showing a main part configuration of the scanner system 100 using the rotary reciprocation drive actuator 1.

The scanner system 100 includes any one of the rotary reciprocation drive actuators 1, 1A to 1D, and further includes a laser light emitting unit 101, a laser control unit 102, a drive signal supply unit 103, and a position control signal calculation unit 104, in addition to the rotary reciprocation drive actuators 1, 1A to 1D.

The laser light emitting unit 101 includes, for example, an LD (laser diode) serving as a light source, a lens system for converging laser light output from the light source, and the like. The laser control unit 102 controls the laser light emitting unit 101. The laser light emitted from the laser light emitting unit 101 enters the mirror 121 which rotationally reciprocates the drive actuator 1.

The position control signal calculation unit 104 refers to the angular position of the rotation shaft 13 (mirror 121) and the target angular position acquired by the angle sensor unit 70, and generates and outputs a drive signal for controlling the rotation shaft 13 (mirror 121) to the target angular position. For example, the position control signal calculation unit 104 generates a position control signal based on the acquired angular position of the rotation shaft 13 (mirror 121) and a signal indicating a target angular position converted using sawtooth waveform data or the like stored in a waveform memory (not shown). The position control signal calculation unit 104 outputs the generated position control signal to the drive signal supply unit 103.

The drive signal supply unit 103 supplies a drive signal for setting the angular position of the rotary shaft 13 (mirror 121) to a desired angular position to the coils 44 and 45 of the rotary reciprocating drive actuator 1 based on the position control signal. Thus, the scanner system 100 can emit scanning light from the rotationally reciprocating drive actuator 1 to a predetermined scanning region.

< summary >

As described above, the rotary reciprocating drive actuator 1 of the present embodiment includes the movable body 10, and the movable body 10 includes the rotary shaft (shaft portion) 13 to which the mirror portion (movable object) is connected, and the magnet 32 fixed to the rotary shaft 13. The magnets 32 are ring magnets having S-poles 32a and N-poles 32b alternately arranged on the outer peripheral surface in the circumferential direction. Further, the rotary reciprocation drive actuator 1 has a fixed body 20, and the fixed body 20 has a core assembly 40.

A preload spring 35 for applying preload to the bearing 22 is inserted outside the rotary shaft 13. The preload spring 35 is disposed between the magnet 32 (specifically, the annular receiving portion 37 integrally fixed to the rotary shaft 13 with the magnet 32) and the bearing 22, for example, on the rotary shaft 13.

The preload spring 35 is abutted against the annular receiving portion 37 and the bearing 22 at both end portions thereof, thereby preventing direct impact from being applied to the magnet 32. That is, the annular receiving portion 37 functions as a stopper, and even when the preload spring 35 receives an external impact or the like and absorbs the impact, the excessive load applied to the magnet 32 can be prevented, and the reliability of driving can be improved.

Further, since the preload is stably applied to the bearing (e.g., ball bearing) 22, the rotation shaft 13 can be rotated with low sliding and high stability against the bearing 22. In this way, according to the rotary reciprocation drive actuator 1, the rotation accuracy can be improved, the rigidity of the shaft can be improved, and the drive with low sliding and high reliability can be performed.

The preload spring 35 is disposed inside the rotary reciprocating drive actuator 1, and is not affected from the outside of the rotary reciprocating drive actuator 1. Accordingly, in the design of the rotary reciprocating drive actuator, quantitative management is possible, and stable pre-compression design is possible.

The sensor substrate 72 covers the periphery of the detection portion (encoder disk) of the sensor member together with the magnet 32 on the outer side of the driving portion 30 (the core 400, the magnet 32). This prevents contamination of the sensor housing 65, and even the air gap G between the magnet and the core 400, by the sensor substrate 72. In this way, the foreign matter can be prevented from being mixed into the air gap G, and malfunction can be prevented, and the air gap G can be properly driven.

Further, since the magnet 32 is disposed inside the driving unit 4 of the rotary reciprocating drive actuator, the magnet is not disposed outside, and the magnetic flux is not distributed outside (on the front side), so that the leakage of the magnetic flux to the front side can be reduced, and even a product having weak magnetism can be disposed around.

Since the core assembly 40 of the driving unit 4 is in the form of a rectangular frame, even in a space where the installation space of the core assembly 40 is limited, for example, a rectangular region (region viewed in the axial direction) of the wall surface in the wall portion 211 of the base portion 21 is located in the rectangular region, a sufficient magnetic path length can be ensured, and the movable body 10 can be driven with high amplitude.

In addition, when the angle sensor unit 70 is maintained, the sensor member, which is a high-volume member in a defective state, can be exposed to the outside by simply removing the fixing member 84, and can be easily modified or replaced.

In addition, in the case where the sensor portion is an optical sensor, interference of light with the sensor housing portion 65 can be prevented without using an additional light shielding member.

When the driving unit 4 is fixed to the main body unit 2, it is preferable to fix the driving unit to a position that can be defined by a predetermined size based on the rotation axis 13. In addition, when the rotary reciprocating drive actuator is fixed to the housing of the product with the shaft standing vertically, the rotary reciprocating drive actuator can be positioned and fixed in a direction parallel to the shaft, and can be assembled and mounted. This makes it possible to perform positioning and fixing with high accuracy with a smaller additional dimension than in the case of assembling in a direction different from the axial direction.

As shown in fig. 4, 11, and 13, in the driving unit 4 of the rotary reciprocating drive actuator 1, the through-hole into which the fixing member 86 of the fastening bottom cover 50, the core assembly 40, and the top cover 60 is inserted and the through-hole into which the fixing member 81 of the fastening top cover 60 and the sensor substrate 72 is inserted are coaxial through-holes extending parallel to the axial direction. That is, since screw holes (through holes) used for fixing the driving unit 4 are commonly used for fastening the sensor substrate 72, it is not necessary to add screw holes for fixing the sensor substrate 72, and cost reduction can be achieved.

A bushing 39 for impact resistance is disposed adjacent to a rotary encoder or the like as a sensor member. Thus, even when the rotation shaft 13 vibrates due to disturbance such as impact received by the rotary reciprocating drive actuator 1, the impact is received by the bushing 39, and the sensor member can be prevented from receiving the impact.

A gap (slit) narrower than the air gap G, G1 between the magnet 32 and the core assembly 40 may be provided between the bushing 39 and the outer periphery of the rotary shaft 13. In this case, the sliding between the bush 39 and the rotary shaft 13 disappears, and the impact resistance can be ensured. Further, if the bush 39 and the rotary shaft 13 are configured to slide, the impact can be reliably received, the impact to the sensor portion can be prevented, and the excessive vibration of the movable body can be damped, thereby reducing noise.

The movable object is a mirror portion 12 (particularly, a mirror 121) that reflects the scanning light. This enables the rotary reciprocation drive actuator 1 to be used for a scanner that performs optical scanning.

As shown in fig. 33, the ring-shaped magnet 32 of the rotary reciprocating drive actuator 1, 1A to 1D of the present embodiment is formed with a U-shaped groove formed in the one end surface 322, but the magnetic pole switching portions 32c, 32D may not be formed with a U-shaped groove. The magnetic pole switching unit may be arbitrarily configured as long as it indicates a position where the magnetic pole changes in the magnet 32. A modification of the magnet 32 will be described with reference to fig. 33 to 37.

Fig. 33 to 37 show modifications 1 to 4 of the magnets in the rotary reciprocating drive actuators 1, 1A to 1D. Fig. 34 to 36 are front and right side views of a magnet as a modification example, and fig. 37 is a diagram showing a core assembly including a rotary reciprocating drive actuator of modification example 4.

The magnets 320, 320A, 320B shown in fig. 34 to 36 are formed on rings having openings 321 in the center through which the rotation shafts 13, 13A are inserted. The magnet 320 shown in fig. 34 has protruding magnetic pole switching portions 32e and 32f integrally formed on a diameter portion of one end face 322.

The magnetic pole switching portions 32e and 32f can determine the switching position of the magnetic pole in the magnet 320 by the shape of the magnet 320.

The magnet 320A shown in fig. 35 has magnetic pole switching portions 32g and 32h having a V-shaped cross section instead of the U-shaped cross section at the end face 322 of the annular main body.

The magnetic pole switching portions 32g and 32h can determine the switching position of the magnetic pole in the magnet 320 by the shape of the magnet 320A.

Here, the assembly accuracy of the magnetic pole directions of the magnets 320, 320A is preferably well balanced with respect to the angle reference of the mirror portion 12 as the movable object and the angle reference of the angle sensor portion 70. If the respective angle references are shifted, there is a problem that the characteristic changes due to the rotation angle of the rotation shaft 13, which is a factor of performance deviation.

In contrast, in the present embodiment, the magnetic pole switching portions 32c to 32h are formed in a U-shape, a protruding shape, a V-shape, or the like in the magnets 32, 320A, and the magnets 32, 320A have a concave-convex shape in the magnetization direction.

Therefore, a positioning jig having pins corresponding to the U-shape, the protruding shape, the V-shape, or the like can be used, and other members or the like can be assembled based on the magnetic pole switching portions 32c, 32d, 32e, 32f, 32g, 32h, or the rotary reciprocating drive actuator can be assembled.

That is, the positional relationship between the members fixed to the rotary shaft 13 can be adjusted at the time of assembling or repairing the rotary reciprocating drive actuator 1 based on the concave-convex portions. In the rotary reciprocation drive actuator 1, the angle reference of the mirror portion 12, the angle reference of the angle sensor portion 70, and the reference of the magnetic poles of the magnet 32 can be easily aligned, and high-precision assembly can be easily achieved.

In addition, if the magnet 32 is configured to have irregularities in the magnetization direction, the magnetic poles 410a and 410b facing the outer peripheral surface and the rotation angle holding portion (magnetic spring) 48 have little influence on the torque, and there is no characteristic deviation in the magnetic attraction force of the rotation angle position holding portion 48.

The magnet 320B shown in fig. 36 has a flat surface 328 in the shape of a cutout of a part of the outer peripheral surface 326. The flat surface 328 is a part of the outer peripheral surface of one of the different magnetic poles of the magnet 320B.

For example, in the case where the core assembly 40B having the magnet 320B is provided in the rotary reciprocating drive actuator 1, the magnetic pole 32B disposed on the opposite side of the magnetic pole 32a to the rotational angle position holding portion 48 shown in fig. 37 has a flat surface 328. The flat surface 328 faces the curved surface of the auxiliary pole 414. Specifically, when the magnet 320B is positioned at the reference position, the flat surface 328 is arranged such that the center of the length in the circumferential direction (horizontal direction) and the center in the circumferential direction (horizontal direction) of the auxiliary pole 414 are positioned on a line passing through the center of the opening 321 (the rotation shafts 13, 13A) and orthogonal to the flat surface 328.

In the magnet 320B, for example, if the flat surface 328 is disposed on the rotation angle position holding portion 48 or the core (magnetic pole 410) side, only a part of the magnet 320B is a flat portion, and therefore, the generated magnetic flux does not flow uniformly, which is considered to have an influence on the magnetic circuit characteristics and deteriorate the performance.

In contrast, in the present embodiment, the flat surface 328 of the magnet 320B is configured to be disposed on the opposite side of the rotation angle holding portion 48 with the rotation shaft 13 interposed therebetween when the magnet is in the non-energized state, for example, when the magnet is positioned at the reference position. Thus, the flat surface 328 can avoid the influence of the rotation angle holding portion 48, that is, the unbalance of the torque generation, and generate the magnetic attraction force with the auxiliary pole portion 414.

The invention proposed by the present inventors has been specifically described above based on the embodiments, but the invention is not limited to the above embodiments and can be modified within a range not departing from the gist thereof.

For example, in the embodiment, the case where the movable object is the mirror portion 12 is described, but the movable object is not limited to this. The movable object may be an imaging device such as a camera, for example.

For example, in the embodiment, the case of driving the actuator 1 rotationally reciprocally by resonance driving has been described, but the present invention can be applied to a case of driving non-resonance.

The configuration of the driving unit 4 is not limited to the configuration described in the embodiment. For example, the core may have a magnetic pole portion that generates polarity when the coil is energized, and the magnetic pole portion and the outer peripheral surface of the magnet may face each other through an air gap when the rotary shaft is attached to the fixed body. The coil may be configured to appropriately generate magnetic flux from one of the magnetic pole portions of the core toward the other when the current is supplied.

The rotation angle position holding portion 48 provided in the fixed body 20 is attached to the second core 42, but the present invention is not limited thereto, and other components provided in the fixed body 20 may be used. In these cases, the rotation angle position holding portion 48 may be housed in the second core 42.

The presently disclosed embodiments are considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than by the description above, and is intended to include all modifications equivalent in meaning and scope to the claims.

Industrial applicability

The present invention is applicable to, for example, liDAR devices, scanner systems, and the like.

Claims (8)

1. A rotary reciprocating drive actuator, comprising:

a movable body having a shaft portion to which a magnet is fixed at an outer periphery thereof, the movable body being capable of reciprocating rotation about the shaft;

a base portion having a pair of wall portions rotatably supporting the shaft portion via a bearing; and

a core assembly including a core body having a plurality of magnetic poles facing an outer periphery of the magnet with the magnet interposed therebetween, a coil body wound around the core body and configured to reciprocate the movable body by generating magnetic flux interacting with the magnet by energization, and a magnet position holding portion configured to generate magnetic attraction force with the magnet to define a reference position for the reciprocation,

the bearing is provided with a preload applying part which is externally inserted in the shaft part and applies preload to the bearing.

2. The rotary reciprocating drive actuator of claim 1 wherein,

one end side of the shaft portion is connected to a movable object between the pair of wall portions, the other end side of the shaft portion is inserted through the bearing of one wall portion of the pair of wall portions and fixed to the magnet outside the one wall portion,

the bearing of the one wall portion is a ball bearing, and the preload-imparting portion is disposed between the bearing of the one wall portion and the magnet.

3. The rotary reciprocating drive actuator of claim 1 wherein,

one end side of the shaft portion is connected to a movable object between the pair of wall portions, the other end side of the shaft portion is inserted through the bearing of one wall portion of the pair of wall portions and fixed to the magnet outside the one wall portion,

the bearing of the one wall portion is a ball bearing, and the preload applying portion is disposed between the bearing of the one wall portion and the movable object.

4. The rotary reciprocating drive actuator of claim 1 wherein,

the bearing is a ball bearing having a flange which is engaged with the pair of walls in the axial direction,

The preload-applying portion is configured to apply a force to the bearing of one of the pair of wall portions from the flange portion side of the bearing to an engagement direction of the one wall portion.

5. The rotary reciprocating drive actuator of claim 3,

an annular stop part is arranged at a position between the preload-applying part of the shaft part and the magnet,

the preload applying portion is sandwiched between the annular stopper portion and the bearing.

6. The rotary reciprocating drive actuator of claim 1 wherein,

the preload applying section is a cylindrical coil spring or a wave spring.

7. The rotary reciprocating drive actuator of claim 1 wherein,

the number of the plurality of magnetic poles is two.

8. A rotary reciprocating drive actuator as defined in claim 2 or 3, characterized in that,

the movable object is a mirror that reflects the scanning light.