CN117411273A - Rotary reciprocating drive actuator - Google Patents

Abstract

The present invention provides a rotary reciprocating drive actuator capable of driving a movable object with high amplitude more appropriately, comprising: a movable body having a shaft portion to which the movable object is connected and a magnet fixed to the shaft portion, and supported so as to be capable of reciprocating rotation about an axis; a base portion rotatably supporting the shaft portion via a bearing, the base portion having a pair of wall portions; a core assembly having a core body, a coil body, and a magnet position holding portion, the core body being attached to the other of the pair of wall portions, the core body having a plurality of magnetic poles, the coil body being wound around the core body and reciprocally rotating the movable body by generating magnetic flux that interacts with the magnet by energization, the magnet position holding portion generating magnetic attraction force with the magnet, and defining a reference position for reciprocal rotation; and a sensor substrate that is attached to one of the pair of wall portions, is provided with a sensor that detects a rotation angle of the shaft portion, and is disposed on the one wall portion from one end portion side toward the one wall portion side.

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, as described in patent document 1, the rotary reciprocating drive actuator is provided with an angle sensor for detecting the rotation angle of a rotary shaft connected to a mirror. The scanning accuracy as a scanner greatly depends on the detection accuracy of the angle sensor. In order to improve the detection accuracy of the angle sensor, it is necessary to adjust the assembly position of the angle sensor with high accuracy so as to be in a relationship determined by the relative relationship between the angle sensor and other components of the rotary reciprocating drive actuator such as the mirror.

If the angle sensor is not disposed near the bearing that supports the rotation shaft, it is difficult to accurately detect the rotation angle of the rotation shaft due to the influence of shaft shake. In addition, when the angle sensor is disposed close to the motor, there is a problem that it is difficult to perform appropriate measurement due to the influence of electromagnetic noise, heat generation, and the like from the motor.

The present invention has been made in view of the above-described aspects, and provides a rotary reciprocating drive actuator capable of driving a movable object with a high amplitude more appropriately.

Means for solving the problems

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

a movable body having a shaft portion to which a movable object is connected at one end portion side and a magnet fixed to the shaft portion at the other end portion side, and supported so as to be capable of reciprocating rotation about an axis;

a base portion rotatably supporting the shaft portion via a bearing on the one end portion side, the base portion having a pair of wall portions disposed so as to sandwich the movable object;

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

And a sensor board attached to one of the pair of wall portions, and having a sensor for detecting a rotation angle of the shaft portion, wherein the sensor is disposed on the one wall portion from the one end portion side toward the one wall portion side.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the rotation of the shaft connected to the movable object can be accurately detected, and therefore the movable object can be driven with high amplitude more appropriately.

Drawings

Fig. 1 is an external perspective view of a rotary reciprocation drive actuator according to an embodiment 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 an enlarged view of the preload spring.

Fig. 6 is a diagram showing a wave spring as a modification of the preload spring.

Fig. 7 is an exploded perspective view of the driving unit.

Fig. 8 is a perspective view of the coil body.

Fig. 9 is an exploded view of the coil body.

Fig. 10 is a perspective view showing a connection state of the coil in the coil body.

Fig. 11 is a front side perspective view of the bottom cover.

Fig. 12 is an external perspective view of the angle sensor unit in the rotary reciprocation drive actuator.

Fig. 13 is a front side exploded perspective view of the angle sensor section.

Fig. 14 is a rear side exploded perspective view of the angle sensor section.

Fig. 15 is a diagram for explaining the operation of the magnetic circuit of the rotary reciprocation drive actuator.

Fig. 16 is an external perspective view of modification 1 of the rotary reciprocation drive actuator.

Fig. 17 is a longitudinal sectional view showing modification 1 of the rotary reciprocation drive actuator.

Fig. 18 is an exploded perspective view of modification 1 of the rotary reciprocation drive actuator.

Fig. 19 is a perspective view of a wall portion on the front surface side of modification 1 of the rotary reciprocation drive actuator.

Fig. 20 is a front side exploded perspective view of the sensor unit disposed on the wall portion on the one end side.

Fig. 21 is a diagram showing a main part configuration of a scanner system using a rotary reciprocation drive actuator.

Fig. 22 (a) and (B) are a front view and a right side view of a magnet according to modification 1.

Fig. 23 (a) and (B) are front and right side views of modification 2 of the magnet

Fig. 24 (a) and (B) are a front view and a right side view of modification 3 of the magnet.

Fig. 25 (a) and (B) are a front view and a right side view of modification 4 of the magnet.

Fig. 26 is a diagram showing a core assembly of a rotary reciprocating drive actuator according to modification 4 having a magnet.

In the figure:

1. a rotary reciprocation drive actuator, 2-body unit, 4-drive unit, 10A-movable body, 12-mirror portion, 13-rotation shaft, 14-stopper portion, 15A-stopper portion, 20-fixed body, 21A-base portion, 21A-outer surface, 22, 23-bearing, 30-drive portion, 32, 320A, 320B-magnet, 32A, 32B, 410A, 410B-magnetic pole, 32c, 32d, 32e, 32f, 32g, 32 h-magnetic pole switching portion, 35-preload spring, 37-ring receiving portion, 39-bushing, 40-core assembly, 41-first core, 42-second core (bridge portion), 43-third core, 44, 45-coil, 46, 47-bobbin, 48-rotation angle position holding portion, 49-coil body, 50-base cover, 52-cover body, 53, 321, 732-opening portion, 54, 55, 66-through hole, 56, 205, 705, 725-positioning holes, 57, 207, 707, 727-position adjustment holes, 58-positioning protrusions, 60-top cover, 62-top cover main body, 64-peripheral wall portion, 67-bobbin engagement hole, 70A-angle sensor portion, 72-sensor substrate, 73-substrate holding portion, 74-encoder disk (detected portion), 76-photosensor (sensor), 81, 84, 85, 86-fixing member, 100-laser system, 101-laser light emitting portion, 102-laser control portion, 103-drive signal supply portion, 104-position control signal calculation portion, 121-mirror, 122-mirror holder, 122A, 211A, 212A-insertion hole, 131-one end portion, 132-the other end portion, 133-fitting groove, 203, 215, 402, 702, 703, 723-fixing hole, 211A, 212A-wall portion, 211A, 211Aa, 212A-insertion hole, 213. 213A-bottom, 218-concave, 222, 232-bearing body, 224, 234-flange, 230, 701-sensor arrangement portion, 322-end face, 326-outer peripheral face, 328-flat face, 400-core, 411a, 411 b-rod-like portion, 412-connecting side portion, 413A, 413 b-side portion, 414-auxiliary pole portion, 492-coil frame portion, 494-terminal support portion, 496-terminal, 522-mounting portion, 541-countersink portion, 621-concave portion, 742-mounting shaft 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 base portion 21 including a movable body 10, a base portion 21 rotatably supporting the movable body 10 and having an angle sensor portion 70 attached thereto, and a drive unit 4 for reciprocally rotationally driving 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.

As shown in fig. 1, in the rotary reciprocating drive actuator 1, a main body unit 2 in which a movable body 10 is mounted on a base portion 21 and a drive unit 4 are joined by a fixing member 81. The fixing member 81 may be any member as long as it can fix the main body unit 2 and the driving unit 4 together, and for example, a screw, a male screw such as a screw, or a bolt and a nut may be used.

As shown in fig. 4, the movable body 10 includes 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.

The base portion 21 has a flat plate-like bottom portion 213 and a pair of wall portions 211, 212 arranged to be separated 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 of the bottom 213. 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 (see fig. 4). 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, in the insertion holes 211a, 212a, spot facing portions having a diameter larger than that of the penetrating portions are provided at the opening edges of the outer sides in the axial direction of the wall portions 211, 212, 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 into the insertion holes 211a and 212a of the wall portions 211 and 212 of the base portion 21 from the axial outside, and the flanges 224 and 234 are fitted into the spot facing portions. The bearings 22 and 23 are fixed to the base portion 21 by press fitting or the like 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 212 a. 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 at one end portion 131 of the rotation shaft 13, and a magnet 32 is fastened to the other end portion 132 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.

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. The one end 131 of the rotary shaft 13 is inserted through the one end wall 212, and is connected to the angle sensor 70 on the outer surface side of the wall 212. The angle sensor unit 70 detects the angle of the rotation shaft 13, and is disposed so as to sandwich the mirror unit 12 with the drive unit 4 in the rotary reciprocation drive actuator 1. That is, the angle sensor portion 70 is located away from the magnetic circuit of the drive unit 4 and is disposed in the vicinity of the bearing 23. The details of the angle sensor unit 70 will be described later.

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.

The rotary shaft 13 is provided with a preload spring 35, an annular receiving portion 37, and a magnet 32 in this order from the wall portion 211 side 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.

For example, as shown in fig. 5, 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. By applying a constant-pressure preload to the bearing 22 by the preload spring 35, the fluctuation of the preload amount can be reduced by absorbing the fluctuation of the load by the spring, the expansion and contraction of the rotation shaft 13 due to the temperature difference between the rotation shaft 13 and the base portion 21, and the like, and a stable preload amount 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. 6 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.

< drive Unit 4 >)

The driving unit 4 shown in fig. 2 to 4 and fig. 7 is provided at one of both axially separated end portions of the base portion 21, and constitutes a part of the fixed body 20. The drive unit 4 is disposed so as to be sandwiched in the axial direction between the angle sensor portion 70 and the base portion 21. 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 including 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 one end portions of 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 >)

The first core 41 includes rod-shaped portions 411 (411 a, 411 b), connecting side portions 412, and side portions 413. The first core 41 has opposite magnetic poles 410a and 410b at its tip end, and has a plurality of rod-shaped portions 411 (411 a and 411 b) arranged parallel to each other. The base end portions of the rod-like portions 411 (411 a, 411 b) are connected to a connecting side portion 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 portion 414 extending parallel to the rod-shaped portions 411a and 411b is provided between the rod-shaped portions 411a and 411b at the connecting side portion 412.

The rod-shaped portion 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 portions 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 portions 411a and 411b. Thus, the coils 44 and 45 are arranged to wind the rod-shaped portions 411a and 411b.

When the coils 44 and 45 are energized and excited, the poles at the distal ends of the rod-shaped portions 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 portions 411a and 411b.

The rod-shaped portions 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 bobbins 46 and 47 can be inserted outward from the distal end sides of the rod-shaped portions 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 portions 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 portion 412 constitutes one side portion of the rectangular core 400, is connected to the base end portions of the rod-shaped portions 411a and 411b, and is disposed so as to extend in a direction orthogonal to the parallel direction of the rod-shaped portions 411a and 411 b.

The connecting side portion 412 mainly connects the base end portions of the rod-like portions 411a and 411b and both side portions 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 portions 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. The other core is disposed so as to be joined to both end portions of the second core 42, and the second core 42 is disposed at a position surrounding the magnet 32 and the magnetic poles 410a, 410b with the other core.

< 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 poles of the rod-shaped portions 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 portions 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 portions 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. The magnetic pole switching parts 32c and 32d function as positioning references for the components of the assembly of the rotary reciprocating drive actuator 1.

In particular, since the magnet 32 is fixed to the rotation shaft 13, the clamp is made to abut against the grooves of the magnetic pole switching portions 32c and 32d in the axial direction, and the rotation of the magnet 32 is restricted, so that the positional relationship between the mirror portion 12 and the sensor member can be adjusted and determined. Further, since the rotation axis 13 serving as the center of the rotary reciprocating drive actuator 1 can be defined as a reference, the dimensions of other members can be easily set, and the actuator can be manufactured with high precision.

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 portions 411a and 411b of the first core 41, and the coils 44 and 45 are disposed so as to wind the rod-shaped portions 411a and 411 b. Thus, the coils 44 and 45 are disposed adjacent to the magnetic poles of the tip ends of the rod-shaped portions 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. 8 is a perspective view of the coil body, fig. 9 is an exploded view of the coil body, and fig. 10 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 parts 411 (411 a, 411 b) are 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 76 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 portions 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 magnetic pole switching portions 32c, 32d of the magnet 32 are aligned with the magnetic poles of the rod-like portions 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. 11 shows a front side view of the top cover. 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. 7 and 11, the through hole 54 has a concave 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 and positioned with the core assembly 40 when combined with the core assembly 40 (see fig. 3 and 4).

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

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 a recess 218 (see fig. 2 and 4) formed in the wall portion 211.

The positioning projection 59 is, for example, an annular projection. On the other hand, as shown in fig. 2 and 4, 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 and 4, the top cover 60 of the present embodiment functions as a sensor housing portion 65 that houses a 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 peripheral wall 64 protruding from the outer peripheral edge of the top cover main body 62 toward the other end 132 side in the axial direction.

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.

The bushing 39 supports the other end 132 side of the rotary shaft 13. The bushing 39 is supported by the top cover 60 on the other end 132 side so that, when the rotation shaft 13 receives an impact or the like, the shaft is not shaken by the impact. The bushing 39 is attached to the top cover 60 such that the other end portion thereof is fitted into the through hole 66 and one end portion thereof 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.

The top cover 60, the core assembly 40 (the core 400), and the bottom cover 50 are fixed by the fixing member 86 through the fixing holes 402, the through holes 54, and the like having the same diameter and continuing in the axial direction.

< Angle sensor portion 70 >)

Fig. 12 is an external perspective view of the angle sensor unit in the rotary reciprocation drive actuator 1, fig. 13 is a front side exploded perspective view of the angle sensor unit, and fig. 14 is a rear side exploded perspective view of the angle sensor unit.

The angle sensor 70 is provided on the outer surface 21a of the wall 212 on the one end side of the base 21.

The angle sensor unit 70 detects the rotation angle of the movable body 10 (the same applies to the mirror unit 12) 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 sensor or an optical sensor. In the present embodiment, the angle sensor portion 70 includes a sensor member, a sensor substrate 72, and a substrate holding portion 73.

The sensor members included in the angle sensor unit 70 include, for example, an encoder disk 74 and a photosensor (sensor) 76 having a light source, a light receiving element, and the like, and the photosensor 76 is mounted on, for example, a sensor substrate 72.

The substrate holding portion 73 holds the mounted sensor substrate 72, and an arrangement space (sensor arrangement portion 701) in which the sensor member is arranged is formed by the sensor substrate 72 and the wall portion 212.

The substrate holding portion 73 is, for example, a plate-like body having an opening 732 in the center, and is fixed to the outer surface 21a of the wall portion 212, and is configured as a concave sensor arrangement portion 701 through which the rotation shaft 13 is inserted. The sensor substrate 72 is mounted on the substrate holding portion 73 so as to cover the internal space. Thereby, the substrate holding portion 73 can house the sensor member in a state of preventing contamination.

The substrate holding portion 73 is formed in a frame shape, but is not limited thereto, and may be formed in a concave shape as long as a space through which the rotation shaft 13 is inserted and the sensor member can be disposed is formed. The substrate holding portion 73 is fixed to the wall portion 212 by inserting and fitting (for example, screwing) the fixing member 85 inserted through the fixing hole 702 into the fixing hole 215 of the wall portion 212.

The encoder disk 74 is fixed to the one end 131 side of the rotary shaft 13 via a central mounting portion (encoder boss) 742, and is disposed in an opening 732 (in the sensor disposition portion 701) of the substrate holding portion 73.

The encoder disk 74 detects the number of rotations of the rotary shaft 13, and rotates integrally with the magnet 32 and the mirror portion 12. The rotational position of the encoder disk 74 about the shaft is the same as the rotational position of the rotary shaft 13.

The photosensor 76 is disposed opposite the encoder disk 74. 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 thereof. This allows the rotational positions of the magnet 32 and the mirror portion 12 to be accurately detected with high resolution.

The light sensor 76 is mounted on the back surface of the sensor substrate 72. The sensor substrate 72 is attached to the substrate holding portion 73, and thereby the optical sensor 76 is disposed in the sensor disposition portion 701 so as to face the encoder disk 74 in the axial direction. The photosensor 76 is disposed in the photosensor disposition portion 701 so as to be able to detect the number of revolutions and the rotational position of the encoder disk 74.

The sensor substrate 72 is disposed so as to close the opening 732 of the substrate holding portion 73 from the one end 131 side, and forms a closed sensor disposition portion 701.

The sensor board 72 has an opening 724 in the center, and a mounting shaft portion (encoder hub) 742 for mounting the encoder disk 74 and the rotation shaft 13 are inserted into the opening 724, so that the sensor board 72 can support them. The fixing member 84 is fixed to the fixing hole 703 of the substrate holding portion 73 via the fixing hole 723, and the sensor substrate 72 is thereby fixed to the substrate holding portion 73. Thus, the sensor substrate 72 is fixed to the substrate holding portion 73 fixed to the wall portion 212, and is therefore fixed to the wall portion 212 via the substrate holding portion 73.

The wall 212, the substrate holder 73, and the sensor substrate 72 are provided with positioning holes 205, 705, 725 and position adjustment holes 207, 707, 727 for positioning and fixing the angle sensor 70 at appropriate positions on the wall 212.

The positioning holes 205, 705, 725 are disposed on the same axis parallel to the rotation axis 13 so as to have the same diameter (including substantially the same diameter). The position adjustment holes 207, 707, 727 are arranged coaxially with the rotation shaft 13 so as to be identical in shape to each other, and are formed so as to form a gap when a rod-like adjustment member (not shown) is inserted.

According to this structure, before the wall portion 212, the substrate holding portion 73, and the sensor substrate 72 are fixed by the fixing member 84, an adjustment member (not shown) is inserted into the position adjustment holes 207, 707, 727. In this state, the wall 212, the substrate holding portion 73, and the sensor substrate 72 can be moved to be adjusted to appropriate positions, and the rod-shaped positioning members can be inserted so as to be inserted into the positioning holes 205, 705, 725. Thus, the substrate holding portion 73 and the sensor substrate 72 are positioned at appropriate positions with respect to the wall portion 212 about the rotation axis 13. In this state, the substrate holding portion 73 and the sensor substrate 72 can be fixed to the wall portion 212 at appropriate positions.

The sensor substrate 72 is fixed to the substrate holding portion 73 via a fixing member 84 inserted through the fixing hole 703 so that the optical sensor 76 is mounted in the opening 732 so as to face the encoder disk 74.

The sensor substrate 72 can prevent unwanted objects such as garbage from the outside from entering the sensing portion of the angle sensor portion 70 including the photosensor 76 and the encoder disk 74 by only being attached to the substrate holding portion 73.

The operation of the rotary reciprocation drive actuator 1 will be described below with reference to fig. 3 and 15. Fig. 15 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 portions 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 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. 15, 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. 15.

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. 21). 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 ac wave corresponding to the determined resonance frequency Fr, a high vibration output can be obtained with good efficiency.

Modification 1 >

Fig. 16 is an external perspective view of modification 1 of the rotary reciprocation drive actuator, and fig. 17 is a longitudinal sectional view through the axial center of modification 1 of the rotary reciprocation drive actuator. Fig. 18 is an exploded perspective view of modification 1 of the rotary reciprocation drive actuator, and fig. 19 is a perspective view of a wall portion on one end side of modification 1 of the rotary reciprocation drive actuator. Fig. 20 is a front side exploded perspective view of the sensor portion disposed on the wall portion on the one end side.

The rotary reciprocation drive actuator 1A of modification 1 is different from the rotary reciprocation drive actuator 1 having a substantially similar structure in that only the substrate holding portion of the angle sensor portion 70A attached to the wall portion 212A on the one end side of the base portion 21A is provided in the wall portion 212A, and the other structures 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 shown in fig. 16 to 20, the movable body 10A is attached to the base portion 21A, and the main body unit 2A is configured. The movable body 10 is assembled to the base portion 21A to constitute the main body unit 2A. The base portion 21A and the driving unit 4 constitute a fixed body 20A that supports the movable body 10 so as to be rotatable in a reciprocating manner. The rotary reciprocation drive actuator 1A has an angle sensor portion 70A in a wall portion 212A as one end portion of the main body unit 2A, and has a drive unit 4 in a wall portion 211A disposed on the other end portion side of the main body unit 2A. The angle sensor portion 70A includes an encoder disk 74, a photosensor 76, and a sensor substrate 72.

In comparison with the rotary reciprocation drive actuator 1, the rotary reciprocation drive actuator 1A does not have a substrate holding portion, but the function of the substrate holding portion is integrally provided in the wall portion 212A. The wall 212A is erected vertically from both ends of a flat plate-like bottom 213A, which is formed similarly to the bottom 213, together with the wall 211A, and is opposed to each other so as to be separated from each other. The wall 212A of the base 21A is provided with a concave sensor arrangement portion 230 that opens in the direction of the other end 131.

Specifically, the wall portion 212A on the other end side of the base portion 21A configured similarly to the base portion 21 has a frame-shaped peripheral wall portion 240, and the frame-shaped peripheral wall portion 240 has the same function as the substrate holding portion 73. The outer surface 21a of the wall 212A is provided with a concave sensor arrangement portion 230 at a central portion surrounded by a frame-like peripheral wall portion 240. One end 131 of the rotary shaft 13 inserted through the wall 212A protrudes toward the sensor arrangement portion 230.

The sensor arrangement unit 230 has the same structure as the embodiment, and the encoder disk 74 is fixed to the rotary shaft 13 via the mounting shaft portion 742. The sensor substrate 72 is attached to the wall 212A such that the optical sensor 76 attached to the sensor substrate 72 faces the encoder disk 74 in the sensor arrangement portion 230.

The sensor substrate 72 is attached to the outer surface 21a of the wall portion 212A with the fixing member 84 via the fixing holes 723 and 215 so as to cover the sensor arrangement portion 230. According to the structure of the rotary reciprocation drive actuator 1A, the same effect as in the embodiment is obtained, and it is not necessary to use a separate member as the substrate holding portion, so that the number of parts can be reduced, and the manufacturing time can be shortened. In addition, when the sensor substrate 72 is attached to the wall 212A, the sensor substrate 72 can be positioned at an appropriate position on the wall 212A with the rotation shaft 13 as the center by the positioning holes 205 and 725 and the position adjustment holes 207 and 727 provided in the wall 212 and the sensor substrate 72.

< scanner System 100>

Fig. 21 is a block diagram showing a main part configuration of a scanner system 100 using the rotary reciprocation drive actuator 1.

The scanner system 100 includes one of the rotary reciprocation drive actuators 1 and 1A, 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 and 1A.

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.

The rotation shaft 13 is rotatably supported by a pair of wall portions 211, 212 of the base portion 21. The core assembly 40 is attached to the other wall 211 of the pair of walls 211, 212, and an angle sensor 70 for detecting the rotation angle of the rotary shaft 13 is disposed in one wall 212 of the pair of walls 211, 212. The angle sensor 70 is provided with a sensor (photosensor) 76, and the sensor substrate 72 is provided with a sensor on one wall 212 from one end 131 side toward the one wall.

In this way, since the angle sensor member (encoder disk, etc.) is disposed in the vicinity of the bearing 23 at a position separated from the core assembly 40, there is no concern about electromagnetic noise, heat generation, and mechanical influence from the core assembly during driving, and there is no influence of shaft vibration of the rotary shaft 13, so that angle detection can be performed appropriately. Thus, the rotation of the shaft connected to the movable object can be accurately detected, and the movable object can be driven with a high amplitude more appropriately.

The sensor substrate 72 covers a detection portion (encoder disk) of the sensor member on the outer side of the sensor arrangement portions 701 and 230. This can prevent contamination of the sensor arrangement portions 701 and 230 with the sensor substrate 72. In this way, the foreign matter is prevented from being mixed into the sensor arrangement parts 701 and 230, and the movable object can be driven so as to be suitable for accurate rotation angle detection.

The angle sensor unit 70 is configured by disposing an encoder disk 74 as a detection unit at one end 131 of the rotation shaft 13, and facing a photosensor 76 mounted on the sensor substrate 72 in the axial direction of the rotation shaft 13. According to this configuration, the configuration in which the angle sensor portion 70 is arranged in a layout that minimizes the size of the rotary reciprocating drive actuator 1 itself, and the optical sensor 76 can be stably held.

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 recovered or replaced.

In addition, in the case where the sensor unit is an optical sensor, interference of light with the sensor arrangement units (the housing unit housing the sensor) 701 and 230 can be prevented without using a 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 the rotary reciprocating drive actuator 1 can be assembled and attached to the housing. This makes it possible to perform highly accurate positioning and fixing with a smaller additional dimension than in the case of assembling in a direction different from the axial direction.

A gap (slit) narrower than the air gap 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. 22, the ring-shaped magnet 32 of the rotary reciprocating drive actuator 1, 1A of the present embodiment is configured by a U-shaped groove formed in the one end surface 322, but the magnetic pole switching portions 32c, 32d may not be configured by 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. 22 to 26.

Fig. 22 to 26 show modifications 1 to 4 of the magnets in the rotary reciprocating drive actuators 1, 1A. Fig. 23 to 25 are front and right side views of a magnet as a modification example, and fig. 26 is a diagram showing a core assembly including a rotary reciprocating drive actuator according to modification example 4, and corresponds to an end view of a line A-A of fig. 2 of the rotary reciprocating drive actuator including a magnet 32.

The magnets 320, 320A, 320B shown in fig. 23 to 25 are each annular, and each have an opening 321 in the center through which the rotation shafts 13, 13A are inserted.

The magnet 320 shown in fig. 23 integrally has protruding magnetic pole switching portions 32e and 32f on a diameter portion of one end face 322. The magnetic pole switching portions 32e and 32f are protruding bodies (protruding shapes) formed on the end surface 322 on the same straight line with the opening 321 interposed therebetween, and the tip end surface may be circular or flat.

By the magnetic pole switching portions 32e, 32f, the magnet 320 can determine the switching position of the magnetic poles in the magnet 320 by its shape.

In addition, as compared with the magnet 320, the magnet 320A shown in fig. 24 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.

By the magnetic pole switching portions 32g, 32h, the magnet 320A can determine the switching position of the magnetic pole in the magnet 320A by its shape.

Here, in addition to the magnet 32, the assembly accuracy of the magnetic pole directions of the magnets 320, 320A is preferably arranged with good balance in combination with 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 assembly, maintenance, or the like of the rotary reciprocating drive actuator 1 based on the concave-convex portions (the magnetic pole switching portions 32c, 32d, 32e, 32f, 32g, 32 h). 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 position holding portion (magnetic spring) 48 have little influence on the torque, and there is no variation in the characteristics of the magnetic attraction force of the rotation angle position holding portion 48.

For example, the magnet 320B shown in fig. 25 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. 26 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) thereof 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 (or the rotation shaft 13) and orthogonal to the flat surface 328.

In the magnet 320B, for example, if the flat surface 328 is placed opposite to the rotation angle position holding portion 48 or the core (the magnetic poles 410a and 410B), only a part of the magnet 320B is a flat portion, and therefore, the generated magnetic flux is not balanced in flow, which is considered to have an influence on the magnetic circuit characteristics and to 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. Further, other components and the like may be assembled with the flat surface 328 based on the magnet 320B, or the rotary reciprocating drive actuator may be assembled.

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. For example, the rotation angle position holding portion 48 may be provided so as to protrude from the front surface of the cover main body 52 or the rear surface of the top cover main body 62 so as to be disposed at the same position as the position where the second core 42 is attached. In the above case, the rotation angle position holding portion 48 may be housed in the driving unit 4.

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 (5)

1. A rotary reciprocation drive actuator is characterized by comprising:

a movable body having a shaft portion to which a movable object is connected at one end portion side and a magnet fixed to the shaft portion at the other end portion side, and supported so as to be capable of reciprocating rotation about an axis;

a base portion rotatably supporting the shaft portion via a bearing on the one end portion side, the base portion having a pair of wall portions disposed so as to sandwich the movable object;

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

And a sensor board attached to one of the pair of wall portions, and having a sensor for detecting a rotation angle of the shaft portion, wherein the sensor is disposed on the one wall portion from the one end portion side toward the one wall portion side.

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

the number of the plurality of magnetic poles is two.

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

the sensor is a photosensor.

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

the one end portion side of the one wall portion has a substrate holding portion that surrounds the sensor and that mounts and holds the sensor substrate.

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

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