Rotary and reciprocating actuator

Abstract

To perform a drive with high rotational accuracy, low friction, and high reliability while improving the rigidity of a shaft.SOLUTION: An actuator comprises: a movable body that has a shaft part in which a magnet is fixed to an outer periphery and can reciprocatingly rotate around a shaft; a base part that has a pair of wall parts for rotatably supporting the shaft part through a bearing; a core body that has a plurality of magnetic poles facing an outer periphery of the magnet so as to sandwich the magnet; a core assembly that has a coil body wound around the core body for reciprocatingly rotating the movable body by energization to generate a magnetic flux that interacts with the magnet and a magnet position holding part for regulating a reference position of the reciprocating rotation by generating a magnetic attraction force between the magnet and itself; and a pre-pressure applying part that is out-fitted to the shaft part and applies a pre-pressure to the bearing.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rotary reciprocating drive actuator. [Background technology]

[0002] Conventionally, rotary reciprocating actuators have been used as actuators for optical scanning devices such as multifunction peripherals, laser beam printers, etc. Specifically, rotary reciprocating actuators rotate the mirror of a scanner back and forth to change the reflection angle of laser light and achieve optical scanning of an object.

[0003] A galvanometer motor is used as this type of rotary reciprocating drive actuator, as disclosed in Patent Document 1. There are various types of galvanometer motors known, including those with the structure disclosed in Patent Document 1 and movable coil types in which the coil is attached to a mirror.

[0004] Patent document 1 discloses a beam scanner in which four permanent magnets are arranged on a rotating shaft to which a mirror is attached so as to be magnetized in the radial direction of the rotating shaft, and a core having magnetic poles around which a coil is wound is arranged on either side of the rotating shaft. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4727509 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in the beam scanner of Patent Document 1, a rotation shaft to which a mirror is attached is rotatably supported via bearings between a pair of wall-shaped bearing holders that stand apart from a fixed base. In a beam scanner having such a configuration, there is a demand for a rotary reciprocating actuator that can improve the rotational accuracy of the rotary shaft relative to the bearing and perform more stable rotary drive.

[0007] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a rotary reciprocating drive actuator that has high rotational accuracy, improved shaft rigidity, and performs low-sliding, highly reliable driving. [Means for solving the problem]

[0008] One embodiment of the rotary reciprocating drive actuator of the present invention comprises: a movable body having a shaft portion with a magnet fixed to its outer periphery and capable of reciprocating rotation around the shaft; a base portion having a pair of walls that rotatably support the shaft portion via a bearing; a core body having a plurality of magnetic poles facing the outer periphery of the magnet so as to sandwich the magnet; and a coil body wound around the core body, which generates a magnetic flux that interacts with the magnet when energized, thereby causing the movable body to rotate back and forth. and a core assembly having 、 before a preload applying portion that is fitted onto the shaft portion and applies a preload to the bearing; 、 and An annular receiving portion is fixed to the shaft portion between the bearing and the magnet, the annular receiving portion being adjacent to the magnet, The preload applying portion is disposed between the annular receiving portion and the bearing, and presses the annular receiving portion and the bearing along the shaft portion. Adopt the configuration. [Effects of the Invention]

[0009] According to the present invention, high rotation accuracy and improved shaft rigidity enable low-sliding, highly reliable driving. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an external perspective view of a rotary reciprocating actuator according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a longitudinal cross-sectional view passing through the axis of the rotary reciprocating actuator. [Figure 3] 2. FIG. 3 is an end view of the portion of the drive unit taken along line AA in FIG. 2, with the left-hand member removed. [Figure 4] FIG. [Figure 5] FIG. 2 is a front perspective view of the main unit with the drive unit removed. [Figure 6] FIG. 2 is a rear perspective view of the main unit with the drive unit removed. [Figure 7] FIG. [Figure 8] Cross-sectional view of line BB in Figure 7. [Figure 9] An enlarged view of the preload spring. [Figure 10] FIG. 10 is a diagram showing a wave spring, which is a modified example of the preload spring. [Figure 11] FIG. 2 is an enlarged perspective view of the front end portion of the rotary reciprocating actuator. [Figure 12] 12 is a perspective view showing the inside of the top cover in FIG. 11 with the sensor board removed. FIG. [Figure 13] 12 is a cross-sectional view taken along line CC in FIG. 11 . [Figure 14] FIG. [Figure 15] FIG. [Figure 16] Exploded view of the bobbin. [Figure 17] FIG. 4 is a perspective view showing a state in which coils are connected in a coil body. [Figure 18] FIG. [Figure 19] 12 is a cross-sectional view taken along line DD in FIG. 11. [Figure 20] 10A and 10B are diagrams illustrating the operation of a magnetic circuit of a rotary reciprocating actuator. [Figure 21] FIG. 10 is a longitudinal cross-sectional view showing a first modified example of the rotary reciprocating actuator. [Figure 22] FIG. 10 is an exploded perspective view of a first modified example of the rotary reciprocating drive actuator. [Figure 23] FIG. 10 is an external perspective view of a second modified example of the rotary reciprocating actuator. [Figure 24] FIG. 10 is a perspective view of a main body unit of a rotary reciprocating actuator according to a second modified example. [Figure 25] FIG. 10 is a front view showing the configuration of the main part of the drive unit in a second modified example of the rotary reciprocating drive actuator. [Figure 26] FIG. 10 is a perspective view of a second modified example of a rotary reciprocating drive actuator attached to a product. [Figure 27] FIG. 11 is an external perspective view of a third modified example of the rotary reciprocating actuator. [Figure 28] FIG. 11 is an external perspective view of a top cover of a rotary reciprocating actuator according to a third modification. [Figure 29] FIG. 10 is a perspective view showing a third modified example of the rotary reciprocating actuator attached to the product. [Figure 30] FIG. 13 is an external perspective view of a bottom cover of a fourth modified example of the rotary reciprocating actuator. [Figure 31] FIG. 10 is a perspective view showing a fourth modified example of the rotary reciprocating actuator attached to the product. [Figure 32] FIG. 1 is a diagram showing the configuration of a main part of a scanner system using a rotary reciprocating actuator. [Figure 33] 33A and 33B are a front view and a right side view of a first modified example of a magnet. [Figure 34] 34A and 34B are a front view and a right side view of the magnet modification 2. [Figure 35] 35A and 35B are a front view and a right side view of a third modified example of the magnet. [Figure 36] 36A and 36B are a front view and a right side view of a fourth modified example of the magnet. [Figure 37] FIG. 10 shows a core assembly of a rotary reciprocating drive actuator having magnet variant 4. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] Fig. 1 is an external perspective view of a rotary reciprocating drive actuator 1 according to a first embodiment of the present invention, and Fig. 2 is a longitudinal cross-sectional view passing through the axis of the rotary reciprocating drive actuator 1. Fig. 3 is an end view of the portion of Fig. 2 taken along line AA with the left-hand members removed from the front end face 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.

[0013] The rotary reciprocating actuator 1 is used in, for example, a LiDAR (Laser Imaging Detection and Ranging) device. The rotary reciprocating actuator 1 can also be applied to optical scanning devices such as multifunction peripherals and laser beam printers.

[0014] The rotary reciprocating actuator 1 is broadly composed of a movable body 10, a base portion 21 that rotatably supports the movable body 10, and a drive unit 4 that drives the movable body 10 to rotate back and forth relative to the base portion 21. The base portion 21 and drive unit 4 form a fixed body 20 that supports the movable body 10 to rotate back and forth.

[0015] In addition, in the rotary reciprocating actuator 1, the movable body 10 is attached to a base portion 21 to form a main unit 2, and the rotary reciprocating actuator 1 has a drive unit 4 at one end of the main unit 2.

[0016] 5 is a front perspective view of the main unit 2 with the drive unit 4 removed, and FIG. 6 is a rear perspective view of the main unit 2 with the drive unit 4 removed.

[0017] 5 and 6, the main unit 2, in which the movable body 10 is mounted on the base portion 21, and the drive unit 4 are attached by a fastening member 81. Note that the fastening member 81 may be any member that can fasten both together, and for example, a male screw such as a screw or a bolt nut may be used.

[0018] The movable body 10 has a rotation axis 13, a mirror portion 12, and a movable magnet (hereinafter simply referred to as a "magnet") 32. Details of the magnet 32 ​​will be explained in detail together with the drive unit 4 described later.

[0019] The mirror section 12 is a movable object in the rotary reciprocating actuator 1, and is connected to the rotary shaft 13. The mirror section 12 is formed, for example, by attaching a mirror 121 to one surface of a mirror holder 122. The rotary shaft 13 is inserted into and fixed to an insertion hole 122a of the mirror holder 122. The mirror section 12 reflects the scanning light.

[0020] 7 is a perspective view of the main unit, and FIG. 8 is a cross-sectional view taken along line BB in FIG. 4 to 8, the base portion 21 has a flat bottom portion 213 and a pair of wall portions 211, 212 that are spaced apart from each other. The bottom portion 213 is flat and extends in the axial direction, with the pair of wall portions 211, 212 erected on each end of the bottom portion 213 so as to face each other. The cross section of the base portion 21 is formed into a substantially U-shape by the bottom portion 213 and the pair of wall portions 211, 212.

[0021] The pair of walls 211, 212 are each shaped like a rectangular plate, and have insertion holes 211a, 212a formed in the center thereof. Bearings 22, 23 are fitted into the insertion holes 211a, 212a, and the rotary shaft 13 is inserted into the bearings 22, 23.

[0022] The insertion holes 211a, 212a are provided with counterbore portions at the axially outer opening edges, each having a larger diameter than the portion that passes through. The flanges 224, 234 of the bearings 22, 23 are fitted into these counterbore portions.

[0023] The bearings 22, 23 have flanges 224, 234 provided on the opening edge on one side of the doughnut-shaped bearing bodies 222, 232. The bearings 22, 23 are fitted into the wall portions 211, 212 of the base portion 21 from the outside in the axial direction, so that the flanges 224, 234 fit into the counterbore portions. The bearings 22, 23 are fixed to the base portion 21 in a state in which the bearings 22, 23 are prevented from coming off in the fitting direction.

[0024] This prevents the bearing bodies 222, 232 of the bearings 22, 23 from protruding outward from the wall portions 211, 212 of the base portion 21, making it possible to make the wall portions 211, 212 of the base portion 21 thinner, and ultimately shortening the overall length and miniaturizing the rotary reciprocating drive actuator 1.

[0025] Furthermore, flanges 224, 234 of bearings 22, 23 are fitted into countersunk portions on the axially outer sides of insertion holes 211a, 212a (on the outer surfaces of wall portions 211, 212). This allows the fitting state of flanges 224, 234 and insertion holes 211a, 212a to be easily visually confirmed and measured from the outside of wall portions 211, 212 during assembly of main unit 2.

[0026] The bearings 22, 23 may be rolling bearings (for example, ball bearings) or plain bearings for the base portion 21. For example, if the bearings 22, 23 are rolling bearings, the coefficient of friction is low and the rotating shaft 13 can be rotated smoothly, thereby improving the driving performance of the rotary reciprocating drive actuator 1. As a result, the rotating shaft 13 is rotatably attached to the base portion 21 via the bearings 22, 23, and the mirror portion 12, which is a movable object, is disposed between the pair of wall portions 211, 212.

[0027] The rotary shaft 13 is inserted through the bearings 22 and 23, and both ends of the rotary shaft 13 protrude outward in the axial direction from the bearings 22 and 23. The bearings 22 and 23 support the rotary shaft 13 on the base portion 21 so that the rotary shaft 13 can rotate freely around its axis.

[0028] The mirror unit 12, which is the movable object, is fixed to one end of the rotating shaft 13 at a portion inserted between a pair of wall portions 211, 212 of the base portion 21, and a magnet 32 ​​is fixed to the other end 132 of the rotating shaft 13. As a result, the rotating shaft 13 is pivotally supported by the pair of wall portions 211, 212 of the base portion 21. The base portion 12 supports the mirror unit 12, which is disposed between the pair of wall portions 211, 212, from both sides via the rotating shaft 13, and therefore the mirror unit 12 can be supported more firmly than in a configuration in which the rotating shaft is pivotally supported by a cantilevered rotating shaft, resulting in improved shock resistance and vibration resistance.

[0029] One end of the rotating shaft 13 is connected to the mirror section (movable object) 12 between a pair of wall sections 211, 212, and the other end 132 of the rotating shaft 13 is inserted through a bearing (ball bearing) 22 of one wall section 211 of the pair of wall sections 211, 212 and fixed to a magnet 32 ​​outside the one wall section 211.

[0030] The magnet 32 ​​is disposed within the drive unit 4, which will be described later, and is driven to rotate back and forth by the magnetic flux generated by the drive unit 4. The rotating shaft 13 rotates the mirror section 12 back and forth by the mutual electromagnetic interaction between the drive unit 4 and the magnet 32.

[0031] In the rotating shaft 13, a stopper (retaining ring) 14 is fitted into a fitting groove 133 at one end 131 that protrudes outside the bearing 23, and this stopper 14 restricts the movement of the rotating shaft 13 toward the other end 132.

[0032] A cylindrical stopper portion 15 is fitted onto the rotary shaft 13 at a location between the mirror holder 122 of the mirror portion 12 and the wall portion 212 on the one end portion 131 side of the pair of wall portions.

[0033] The stopper portion 15 is fixed to the rotary shaft 13. Movement of the rotary shaft 13 toward one end 131 is restricted by a bearing 23, and movement of the rotary shaft 13 toward the other end 132 is restricted by a stopper portion 14. The mirror portion 12 fixed to the rotary shaft 13 is restricted from moving toward the other end 132 in the axial direction relative to the base portion 21 via the stopper portion 14.

[0034] The stopper portion 15 prevents the rotary shaft 13 from slipping out of the bearing 23 via the mirror portion 12 toward one end in the axial direction, that is, toward the outside.

[0035] The stopper portion 15, together with the retaining portion 14, restricts the axial movement of the movable body 10, including the mirror portion 12, the rotating shaft 13, and the magnet 32, to within a predetermined range including tolerances, etc., thereby preventing it from coming off the base portion 21.

[0036] The rotating shaft 13 is disposed on the base portion 21 such that the other end 132 side of the base portion 21 passes through the bearing 22 and protrudes from the wall portion 211 to the outside of the base portion 21. The portion protruding from the wall portion 211 passes through the inside of the drive unit 4.

[0037] The magnet 32 ​​fixed to the other end 132 of the rotary shaft 13 is disposed at a portion that protrudes outward from the wall portion 211 of the base portion 21 .

[0038] In the rotating shaft 13, a preload spring (preload applying portion) 35, an annular receiving portion 37, and a magnet 32 ​​are arranged 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.

[0039] The preload spring 35 expands and contracts in the axial direction to axially bias the bearing 22. The preload spring 35 is particularly disposed in one wall portion 211 between the bearing 22, which is a ball bearing, and the magnet 32. The preload spring 35 is, for example, as shown in FIG. 9, a cylindrical coil spring having a predetermined length L1 corresponding to the space in which the preload spring 35 is placed and having flat surfaces formed on both ends spaced apart in the predetermined length direction.

[0040] The preload spring 35 is disposed so as to be fitted onto the rotary shaft 13 , and biases the magnet 32 ​​in a direction separating it from the bearing 22 fitted into the wall portion 211 . The preload spring 35 is interposed between the bearing 22 and the annular receiving portion 37 adjacent to the magnet 32 ​​when the rotary shaft 13 is inserted therethrough.

[0041] The preload spring 35 applies a constant preload to the bearing 22. As a result, even if fluctuations in the load on the rotating shaft 13 or expansion and contraction of the rotating shaft 13 due to temperature differences between the rotating shaft 13 and the base portion 21 during rotation occur, these are absorbed by the preload spring 35, reducing fluctuations in the amount of preload on the bearing 22 and providing a stable amount of preload. Therefore, the preload spring 35 prevents high-speed rotation of the rotating shaft 13 and axial vibration of the rotating shaft 13, enabling the rotating shaft 13 to be rotated at higher speeds and preventing axial vibration compared to a fixed-position preload.

[0042] The preload spring 35 applies a preload to the bearings (particularly the ball bearings) 22 and 23, thereby maintaining low sliding properties and high reliability of the rotational drive of the rotary shaft 13, and enabling stable drive.

[0043] It is desirable that the preload spring 35 be configured to come into contact with a firmly fixed part and receive the preload from that part. The annular receiving part 37 is a press-fit ring, and is fixed to the rotating shaft 13 by being press-fitted onto the outer periphery of the rotating shaft 13.

[0044] The annular receiving portion 37 receives one end of the preload spring 35, which abuts against the bearing 22 at one end side, thereby preventing a direct impact from being applied to the magnet 32, which is an adhesively fixed component. This prevents unnecessary force from being applied to the magnet 32, thereby improving reliability.

[0045] Furthermore, since the preload spring 35 is disposed inside the rotary reciprocating drive actuator 1, it is not affected by the outside of the rotary reciprocating drive actuator 1, and a stable preload design can be ensured.

[0046] Incidentally, the preloading spring 35 may be changed to a cylindrical coil spring formed by helically winding a round steel wire, or may be a wave spring having a shape in which a plate-shaped steel wire is helically or annularly wound and waves are added, as a spring having a low height as a spring in the expansion and contraction direction, that is, in the spring direction.

[0047] For example, as the preloading spring 350 having an axial length shorter than that of the cylindrical coil spring with an axial length L1 as the preloading spring 35, the preloading spring 350 as the wave spring shown in FIG. 10 may be used.

[0048] In the preloading spring 350 which is a wave spring, the axial length L2 in the expansion and contraction direction is shorter than the length L1 of the cylindrical coil spring, and the expansion and contraction length is short.

[0049] When the preloading spring 350 is to correspond to conditions such as the length L0 of the wall portion 211 and the annular receiving portion 37 being in the range of L2 < L0 < L1, the expansion and contraction length can be changed by stacking a plurality of preloading springs 350 in the direction of the length L2.

[0050] Thus, the preloading springs 35 and 350 can be appropriately changed according to the installation location or the preloading target to adjust the preloading force, prevent suitable high-speed rotation and axial vibration, and drive stably.

[0051] FIG. 11 is an enlarged perspective view of the front end portion of the rotary reciprocating drive actuator, FIG. 12 is a perspective view showing the inside of the top cover with the sensor board 72 removed in FIG. 11, FIG. 13 is a cross-sectional view taken along the arrow C-C line in FIG. 11, and FIG. 14 is an exploded perspective view of the drive unit.

[0052] <Drive unit 4> The drive unit 4 shown in Figures 2 to 6 and 11 to 14 is provided at one of both ends separated in the axial direction of the base part 21, and constitutes a part of the fixed body 20. The drive unit 4 constitutes the drive part 30 together with a 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 drive unit 4 is formed, for example, in the shape of a rectangular parallelepiped that is square when viewed from the front.

[0053] <Core assembly 40> The core assembly 40 shown in FIGS. 3, 4 and 14 includes coils 44, 45, bobbins 46, 47 around which the coils 44, 45 are wound, a core body 400, and a rotation angle position holder .

[0054] In this embodiment, core assembly 40 is formed in the shape of a rectangular frame-type block (more specifically, a rectangular parallelepiped shape) with magnetic poles 410a, 410b arranged inside. Core assembly 40 is formed such that the outer periphery of the frame surrounds magnetic poles 410a, 410b arranged inside the outer periphery. For example, core assembly 40 extends back from each of magnetic poles 410a, 410b that sandwich magnet 32 ​​within a rectangular region of the wall surface of wall portion 211 of base portion 21 as viewed from the axial direction, forming a single magnetic path surrounding magnetic poles 410a, 410b.

[0055] <Core Body 400> The core body 400 constitutes a magnetic circuit having a magnetic path arranged to surround the magnet 32. The core body 400 has an integrated first core 41 including a plurality of magnetic poles 410a, 410b and a C-shaped magnetic path portion (connecting side portions 412 and side portions 413), a second core 42 arranged to bridge between the side portions 413 of the first core 41, and a frame-shaped third core 43. The core body 400 is integrated by magnetically coupling the first to third cores.

[0056] The first core 41 to the third core 43 allow magnetic flux generated when current is passed through the coils 44, 45 to pass through the multiple magnetic poles 410a, 410b. The first core 41 to the third core 43 are laminated cores formed by laminating electromagnetic steel sheets (laminated members) such as silicon steel sheets. By making the core body 400 have a laminated structure, the first core 41 to the third core 43 can be formed at low cost and with complex shapes.

[0057] <1st Core 41> In the first core 41, a connecting side 412 extending perpendicular to the direction of extension of a plurality of rod-shaped bodies 411 (411a, 411b), each having opposing magnetic poles at their tip ends, is connected to the base ends of the rod-shaped bodies 411. Side sides 413a, 413b protrude perpendicularly from both ends of the connecting side 412. An inter-pole portion 414 is provided on the connecting side 412 between the rod-shaped bodies 411a, 411b and extending parallel to the rod-shaped bodies 411a, 411b.

[0058] The rod-shaped body 411 (411a, 411b), the connecting side portion 412, the side portion 413 (413a, 413b), and the interpole portion 414 are integrally formed, and the first core 41 has a comb-tooth shape.

[0059] The rod-shaped bodies 411a and 411b each have a magnetic pole disposed on the side surface of the tip, and bobbins 46 and 47 are fitted around the outer periphery of the rod-shaped bodies 411a and 411b on the base end side, so that the coils 44 and 45 are arranged to be wound around the rod-shaped bodies 411a and 411b.

[0060] When coils 44, 45 are energized and magnetized, the magnetic poles at the tips of rod-shaped bodies 411a, 411b produce polarities that correspond to the direction of energization. The magnetic poles are arranged to face magnet 32, and each magnetic pole has a curved shape that follows the outer circumferential surface of magnet 32. These curved shapes are arranged to face each other in a direction perpendicular to the extension direction of rod-shaped bodies 411a, 411b, for example.

[0061] The rod-shaped bodies 411a, 411b have external dimensions that allow the bobbins 46, 47 to be fitted around the rod-shaped bodies 411a, 411b from their respective tip ends. This allows the bobbins 46, 47 to be fitted around the tip ends of the rod-shaped bodies 411a, 411b in the direction of extension, i.e., the tips of the magnetic poles 410a, 410b, and positioned around the base ends of the rod-shaped bodies 411a, 411b so as to surround them. The fitted bobbins 46, 47 are each disposed between the side edge portion 413 and the inter-pole portion 414.

[0062] The connecting side 412 constitutes one side of the rectangular core body 400, connects the base ends of the rod-shaped bodies 411a and 411b, and is disposed extending in a direction perpendicular to the parallel direction of the rod-shaped bodies 411a and 411b.

[0063] The connecting side portion 412 mainly connects the base ends of the rod-shaped bodies 411a, 411b to the side portions 413a, 413b. It is preferable that the side portions 413a, 413b are in close contact with both ends of the second core 42, but in this case, they are arranged so that there is a gap between each of the side portions 413a, 413b and both ends of the second core 42. The connecting side portion 412 and both side portions 413a, 413b are provided so as to be stacked together with the second core 42 and the third core 43 in a state of being in close contact with each other in the axial direction.

[0064] The interpole portion 414 is disposed opposite the rotation angle position holder 48, and when the magnet 32 ​​attracts the rotation angle position holder 48, it attracts the other pole of the magnet 32, reinforcing the attraction state with the rotation angle position holder 48.

[0065] Specifically, the interpole section 414 is made of a magnetic material and is arranged, for example, together with the magnetic poles 410a and 410b and the rotation angle position holder 48 so as to surround the magnet 32 ​​on all four sides. The inter-pole portion 414 generates a magnetic attractive force between itself and the magnet 32 ​​(more specifically, the pole 32b), and moves the pole 32b of the magnet 32, which is different from the pole 32a that is attracted to the rotation angle position holder 48, to a position facing the pole 32b. Through this action, the inter-pole portion 414 cancels out the radial load acting on the movable body 10 due to the magnetic attractive force in the rotation angle position holder 48. Note that "canceling the radial load" also includes "making it possible to cancel out the radial load."

[0066] The inter-pole surface of inter-pole section 414 that faces the outer circumferential surface of magnet 32 ​​is a curved surface that corresponds to the shape of the outer circumferential surface of magnet 32, and has a uniform gap across the entire surface between it and the outer circumferential surface of magnet 32. Inter-pole section 414, together with rotational angle position holder 48, is arranged so as to surround magnet 32 ​​within core assembly 40, and therefore can be laid out in a minimal space, enabling a more compact rotary reciprocating drive actuator 1 to be realized.

[0067] <Second Core 42> The second core 42, together with the first core 41, constitutes a magnetic path that is arranged to surround the magnetic poles at the tips of the rod-shaped bodies 411a and 411b on all sides. The second core 42 is formed in a rectangular column shape, and forms a magnetic path through which magnetic flux passes to the magnetic poles 410a and 410b when current is applied to the coils 44 and 45.

[0068] The second core 42 has the same thickness (length in the axial direction) as both side portions 413a, 413b. 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 fastening members 86 inserted into fastening holes 402 similar to the fastening holes 402 provided at both ends of the connecting side portion of the first core 41 (see FIG. 13). The fastening holes 402 have the same diameter as the through-hole 54 of the bottom cover 50 and are formed to extend parallel to the rotation axis 13. A rotation angle position holder 48 is attached to the second core 42 at a central portion in the extension direction and at a portion facing the magnet 32 ​​.

[0069] <3rd Core 43> The third core 43, together with the connecting side portion 412 and both side portions 413 of the first core 41 and the second core 42, surrounds the multiple magnetic poles and forms a magnetic path connecting the multiple magnetic poles. The third core 43 has a rectangular frame plate shape and is attached in surface contact with the rectangular frame portion formed by both the first core 41 and the second core .

[0070] Specifically, the third core 43 faces the connecting side portion 412 and both side portions 413a, 413b of the first core 41 in the extension direction of the rotation shaft 13, and is in surface contact with them. In addition, the third core 43 is assembled to the first core 41 in a state in which the multiple magnetic poles of the rod-shaped bodies 411a, 411b of the first core 41 are positioned around the rotation shaft 13. The third core 43 also faces the second core 42 in the extension direction of the rotation shaft 13, and is in surface contact with them.

[0071] As a result, the third core 43 is disposed around the rotation shaft 13 so as to surround the magnetic poles of the rod-shaped bodies 411a, 411b and the coils 44, 45, forming a seamless magnetic path around the rotation shaft 13. The first to third cores 41-43 have surrounding portions that surround the coils 44, 45, and can form a flow of magnetic flux that passes from one magnetic pole through the first core 41 + third core 43, the third core 43, the third core 43 + second core 42, and the other magnetic pole of the third core 43 + first core 41 in this order. In addition, the first to third cores 41-43 annularly surround the magnetic poles and the magnet 32 ​​between the magnetic poles, thereby preventing contact with the coils 44, 45 from outside.

[0072] When the drive unit 4 is assembled, the rotating shaft 13 is inserted into the space surrounded by the magnetic poles. The magnet 32 ​​attached to the rotating shaft 13 is positioned in this space, and the magnetic poles face the magnet 32 ​​at a precise position across the air gap G.

[0073] The magnet 32 ​​is a ring-shaped magnet in which south poles 32a and north poles 32b are arranged alternately in the circumferential direction. The magnet 32 ​​is attached to the circumferential surface of the rotating shaft 13 so as to be located in the space surrounded by the magnetic poles 410a, 410b of the core body 400 when the rotary reciprocating drive actuator 1 is assembled. The magnet 32 ​​is fixed so as to surround the outer periphery of the rotating shaft 13. When current is applied to the coils 44, 45, the first core 41, the second core 42, and the third core 43, including the rod-shaped bodies 411a, 411b, are excited, and the magnetic poles 410a, 410b are given polarity according to the direction of current application. As a result, magnetic forces (attraction and repulsion) are generated between the magnetic poles 410a, 410b and the magnet 32.

[0074] In this embodiment, magnet 32 ​​is magnetized with different polarities, with a plane along the axial direction of rotating shaft 13 as the boundary. That is, magnet 32 ​​is a two-pole magnet that is magnetized so as to be equally divided into south pole 32a and north pole 32b. The number of magnetic poles of magnet 32 ​​(two in this embodiment) is equal to the number of magnetic poles 410a, 410b of core body 400. Note that magnet 32 ​​may be magnetized with two or more poles depending on the amplitude during movement. In this case, the magnetic pole portions of core body 400 are provided to correspond to the magnetic poles of magnet 32.

[0075] <Magnet 32> The polarity of magnet 32 ​​is switched at boundary portions 32c and 32d (hereinafter referred to as "magnetic pole switching portions") between south pole 32a and north pole 32b. Magnetic pole switching portions 32c and 32d are formed as grooves extending through the axis on one end surface of magnet 32. Magnetic pole switching portions 32c and 32d directly face magnetic poles 410a and 410b, respectively, when magnet 32 ​​is held in the neutral position.

[0076] If the magnetic pole switching sections 32c and 32d are formed in a groove shape, the positional relationship of each component fixed to the rotary shaft 13 can be adjusted using this groove as a reference when assembling or maintaining the rotary reciprocating drive actuator 1. In particular, the position of the mirror section 12 relative to the rotary shaft 13 and the mounting position of the encoder of the angle sensor section 70 can be determined with suitable precision by matching the positions of the magnetic pole switching sections 32c and 32d of the magnet 32. For example, by placing a jig in the axial direction against the groove and fitting a protrusion into the groove, rotation around the rotary shaft 13 is restricted and immobilized, and this serves as a reference position for other components attached to the rotary shaft 13. In particular, precision is required for adjusting the angle of the mirror relative to the poles of the magnet 32, and this makes this possible.

[0077] In the neutral position, the magnetic pole switching portions 32c and 32d of the magnet 32 ​​directly face the magnetic poles 410a and 410b, so that the drive unit 4 can generate maximum torque and drive the movable body 10 stably.

[0078] Furthermore, by configuring magnet 32 ​​as a two-pole magnet, cooperation with core body 400 makes it easier to drive the movable object with high amplitude and improves drive performance. In other words, mirror 12, which is the movable object, can be driven over a wide angle. Note that, although the embodiment has been described with reference to a case where magnet 32 ​​has a pair of magnetic pole switching portions 32c and 32d, magnet 32 ​​may have two or more pairs of magnetic pole switching portions.

[0079] <Coil body (coil and bobbin)> The coils 44, 45 are wound around cylindrical bobbins 46, 47. A coil body consisting of the coils 44, 45 and the bobbins 46, 47 is extrapolated onto the rod-shaped bodies 411a, 411b of the first core 41, so that the coils 44, 45 are arranged to wind around the rod-shaped bodies 411a, 411b. In this way, the coils 44, 45 are arranged adjacent to the magnetic poles at the tip ends of the rod-shaped bodies 411a, 411b.

[0080] The winding direction of the coils 44, 45 is set so that magnetic flux is suitably generated from one of the multiple magnetic poles of the first core 41 to the other when current is applied.

[0081] 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 the state of connection of the coil in the coil body.

[0082] Since the coil body, which is bobbin 46 around which coil 44 is wound, and the bobbin 47 around which coil 45 is wound have the same configuration, we will explain the coil body having bobbin 46 around which coil 44 is wound, and will omit explaining the coil body having coil 45 and bobbin 47.

[0083] The coil body 49 has a bobbin portion 492 around which the coil 44 is wound, and a terminal support portion 494 that supports a terminal 496 and is provided integrally with the bobbin portion 492.

[0084] The bobbin portion 492 has a through hole through which the rod-shaped body 411 (411a, 411b) is inserted, and a terminal support portion 494 is provided to protrude from a flange on the edge of the opening on one side of the bobbin portion 492.

[0085] The terminal support portions 494 each have a cylindrical shape, and the terminals 496 are inserted thereinto and hold the terminals 496 .

[0086] The terminal 496 is L-shaped, and one side 4962 is wound around and connected to the end of the coil 44, the base end of the other side 4964 is inserted into and supported by the terminal support portion 494, and the tip side of the other side 4964 protrudes outward from the terminal support portion 494.

[0087] The tip end of the other side 4964 is connected to an external device that supplies power to the coil 44 or to the end of an adjacent coil. In this embodiment, the extension direction of one side 4962 of the terminal 496 is parallel to the axial direction of the coil 44, and the extension direction of the other side 4964 is perpendicular to the axial direction of the coil 44.

[0088] In coil body 49, one side 4962 of terminal 496 is arranged to extend in the opening direction of the opening of bobbin portion 492, and the other side 4964 is arranged to extend in the direction in which the flange of bobbin portion 492 protrudes.

[0089] At one side 4962, the coil wires at both ends of the coil 44 are connected to connecting portions H made of solder or the like.

[0090] Thus, terminal 496 is L-shaped, has one side 4962 to which the coil winding is connected (connection portion H which is a fillet), and is joined to sensor substrate 72 at the other side 4964.

[0091] Since terminal 496 is L-shaped, the sensor board wiring side and the coil wiring side can be connected separately, and in particular, the work of forming the connection portion (fillet) H for connecting the coil winding with solder can be easily performed without interference between the solder and the winding.

[0092] That is, even when the work of connecting the sensor board 72 and the work of fixing the winding to the same terminal 494 occur, the process of connecting the board is not hindered by, for example, adhesion of solder when conducting the winding. By arranging the sensor board 72 in the axial direction relative to the drive unit 4, the connection between the sensor board 72 and the terminal 496 can be positioned while taking measures against contamination, and the optical sensor can be easily arranged perpendicular to the axial direction.

[0093] <Rotation angle position holding unit (magnet position holding unit) 48> 2 to 4 is incorporated into the core assembly 40 so as to face the magnet 32 ​​across the air gap G when the rotary reciprocating drive actuator 1 is assembled. The rotational angle position holder 48 is attached to the second core 42, for example, in a position where its magnetic pole faces the magnet 32.

[0094] Rotational angle position holder 48 uses, for example, a magnet with its magnetic pole facing magnet 32 ​​to generate a magnetic attraction force between itself and magnet 32, thereby attracting magnet 32. That is, rotational angle position holder 48, together with rod-shaped bodies 411a and 411b, forms a magnetic spring between itself and magnet 32. This magnetic spring holds the rotational angle position of magnet 32, i.e., the rotational angle position of rotating shaft 13, in a neutral position when coils 44 and 45 are not energized (when not energized).

[0095] At this time, the magnetic pole 32b (north pole shown in FIG. 3) opposite to the magnetic pole 32a (south pole in FIG. 3) of the magnet 32 ​​that is attracted to the rotation angle position holding unit 48 attracts the commutating pole unit 414 of the first core 41, which is a nearby magnetic body. This more effectively holds the magnet 32, that is, the mirror unit 12, which is the movable object, in the neutral position.

[0096] The neutral position is the reference position for the reciprocating rotation of magnet 32, i.e., the center position of the reciprocating rotation (oscillation), and is the position where the left and right rotations around the axis during reciprocating rotation result in the same rotation angle. When magnet 32 ​​is held in the neutral position, boundary portions 32c and 32d of magnet 32 ​​directly face the magnetic poles of rod-shaped bodies 411a and 411b.

[0097] The mounting posture of the mirror unit 12 is adjusted based on the state in which the magnet 32 ​​is in the neutral position. The rotation angle position holder 48 may be made of a magnetic material that generates a magnetic attraction force between itself and the magnet 32.

[0098] <Bottom cover 50 and top cover 60> The bottom cover 50 and top cover 60 shown in FIGS. 1, 2, 4 to 6, and 11 to 14 are preferably made of a non-magnetic, electrically conductive material with high electrical conductivity, and function as an electromagnetic shield.

[0099] 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).

[0100] The bottom cover 50 and the top cover 60 can suppress noise from entering the core assembly 40 and noise from emitting from the core body 400 to the outside.

[0101] The bottom cover 50 and the top cover 60 are made of a non-magnetic, electrically conductive, and highly thermally conductive material, such as an aluminum alloy. Aluminum alloys offer a high degree of design freedom and can easily be given the desired rigidity. Therefore, using an aluminum alloy for the bottom cover 50 and the top cover 60 is suitable when the top cover 60 functions as a support for the rotating shaft 13.

[0102] Fig. 18 is a front perspective view of the bottom cover, and Fig. 19 is a cross-sectional view taken along line DD in Fig. 11 .

[0103] The bottom cover 50 is attached so as to overlap the outer surface of the wall portion 211. The bottom cover 50 is formed in a rectangular plate shape corresponding to the outer shape of the wall portion 211. The bottom cover 50 has a rectangular plate-shaped cover main body 52, and an opening 53 through which the rotating shaft 13 is inserted is formed in the center of the cover main body 52. ​​The opening 53 is positioned opposite 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 be arranged by inserting the rotating shaft 13, on which the magnet 32 ​​is attached, into the opening 53, and inserting the magnet 32 ​​into the core assembly 40.

[0104] The rotary shaft 13 is inserted into the opening 53, and a preload spring 35 is disposed around the rotary shaft 13 (see FIG. 2).

[0105] The cover 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. A fastening member 86 that integrates the bottom cover 50 with the core assembly 40 and the top cover 60 as the drive unit 4 is inserted into the through hole 54. The through hole 55 is formed in an attachment portion 522 that is attached to the wall portion 211. The attachment portion 522 forms left and right sides of the cover body 52 that are spaced apart in a direction perpendicular to the axial direction, and includes four corners of the cover body 52. ​​A through hole 55 is formed in each of these corners.

[0106] 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. By inserting the fastening members 81, 86 into the through holes 54, 55, the attachment to the base portion 21 or the assembly of the drive unit 4, and therefore the assembly of the rotary reciprocating drive actuator 1, can be performed in one axial direction.

[0107] As shown in FIG. 13, the through-hole 54 has a recessed counterbore 541 formed on the rear surface of the cover body 52, and the counterbore 541 accommodates the head of the fastening member 86 such as a screw.

[0108] The core holding projections 58 are provided to project in the axial direction from positions on the cover body 52 that sandwich the opening 53, and when combined with the core assembly 40, they fit into the core assembly 40 to position it.

[0109] The core holding projections 58 are inserted between the rod-shaped bodies 411a, 411b and the side portions 413a, 413b, and prevent leakage of magnetic flux flowing between them.

[0110] 6, a positioning protrusion 59 is provided on the back surface of the bottom cover 50. When the bottom cover 50 abuts against the base portion 21 with their centers aligned, the positioning protrusion 59 engages with the recess 218 of the wall portion 211 to position it.

[0111] The positioning protrusion 59 is, for example, an annular protrusion. On the other hand, the recess 218 of the wall portion 211 is an annular groove formed to surround the insertion hole 211a in the base portion 21, as shown in Figures 5, 7, and 8. The positioning protrusion 59 engages with the recess 218 of the annular groove, and both the wall portion 212 and the drive unit 4 are positioned.

[0112] The top cover 60, together with the bottom cover 50, sandwiches the core assembly 40 from both axial sides and is fixed together with fastening members 86 to form the drive unit 4. As shown in Figures 2, 4 and 12, the top cover 60 of this embodiment functions as a sensor housing that houses an optical sensor 76 that detects the rotation angle of the movable body 10, i.e., the rotation shaft 13.

[0113] The top cover 60 has a top cover main body 62 that covers the tip side surface of the core assembly 40, and a sensor peripheral wall portion (peripheral wall portion) 64 that protrudes from the outer peripheral edge portion of the top cover main body 62 toward the other end portion 132 in the axial direction and forms a concave sensor storage portion 65.

[0114] The top cover body 62 is a plate-like body that is square when viewed in the axial direction and has a recessed portion 621 that opens toward the core assembly 40. The top cover body 62 is a square plate-like body, and the peripheral wall portion 64 is formed in the shape of a rectangular frame that rises from the outer periphery of the top cover body 62.

[0115] A through-hole 66 is provided in the top cover body 62 of the top cover 60. The through-hole 66 is disposed in the top cover body 62 so as to be coaxial with the opening 53 of the bottom cover 50 and the bearings 22, 23 of the base portion 21. A bushing 39, through which the rotating shaft 13 is inserted, is fitted into the through-hole 66 from the rear surface side (one end 131 side). This allows the bushing 39 to be attached to the top cover body 62 with its movement direction restricted. The bushing 39 and the rotating shaft 13 may be arranged to slide relative to each other, or may be arranged with a gap therebetween.

[0116] When the rotating shaft 13 receives an impact, the bushing 39 prevents the impact from being transmitted to the sensor component (encoder disk) on the other end 132 side. The bushing 39 is attached to the top cover 60 so that the other end is fitted into the through-hole 66 and one end is positioned within the recessed portion 621.

[0117] In addition to the through-holes 66, the top cover body 62 is provided with bobbin engagement holes 67 that penetrate in the axial direction and engage with the bobbins 46, 47.

[0118] The terminal support portion 494 of the coil body 49 having the bobbins 46, 47 is fitted into the bobbin engagement hole 67. As a result, the terminal support portion 494 is inserted into the top cover main body 62, and the other side portion 4964 is arranged to protrude from the terminal support portion 494.

[0119] The engagement between the bobbin engagement hole 67 and the terminal support portion 494 also functions as a positioning device when the core assembly 40 and the top cover 60 are assembled together.

[0120] <Angle sensor part 70> An angle sensor unit 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. Based on the detection result of the angle sensor unit 70, the rotary reciprocating drive actuator 1 can control, via the control unit, the rotation angle position and rotation speed of the movable body during driving, specifically, the mirror unit 12, which is the movable object.

[0121] The angle sensor unit 70 may be a magnetic or optical sensor. In this embodiment, the angle sensor unit 70 has a sensor substrate 72, and includes an encoder disk 74 that constitutes the angle sensor unit 70 and is housed in the sensor housing 65, and an optical sensor (sensor) 76 that has a light source, a light receiving element, etc.

[0122] The angle sensor unit 70 detects the rotation angle of the rotary shaft 13, and therefore the mirror unit 12. The encoder disk 74 is fixed to the other end 132 of the rotary shaft 13 inside the sensor housing 65, and rotates integrally with the magnet 32 ​​and the mirror unit 12. In other words, the rotational position of the encoder disk 74 is the same as the rotational position of the rotary shaft 13.

[0123] The optical 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 detecting the rotational positions of the magnet 32 ​​and the mirror section 12.

[0124] The optical sensor 76 is mounted on the sensor substrate 72, which is disposed so as to cover the peripheral wall portion 64 and close the sensor housing portion 65.

[0125] The sensor board 72 is a board on which an optical sensor 76 is mounted, which detects the rotation angle of the rotating shaft 13. The sensor board 72 is disposed so as to cover the core assembly 40 from the other end 132 side, with the optical sensor 76 facing the magnet 32 ​​side. The sensor substrate 72 is provided in the center and has a mounting portion (encoder hub) for mounting the encoder disk, an opening 724 into which the rotary shaft 13 is inserted, as well as a fastening hole 722 and a through hole 726.

[0126] The sensor board 72 is fastened to the top cover 60 via a fastening member 84 . The fastening hole provided in the top cover 60 is formed on an extension of the fastening hole 402 of the core assembly 40, and has the same axis and diameter as the fastening hole. That is, the sensor board 72 is fixed on the core assembly 40 side via the fastening member 84 to a fastening hole of the same diameter that is continuous with the mounting hole (fastening hole) 402 of the core assembly 40.

[0127] In this way, the sensor substrate 72, top cover 60, core assembly 40 (core body 400), and bottom cover 50 are fixed by fastening members through holes of the same diameter that are continuous in the axial direction, such as fastening holes, mounting holes 402, and through holes 54.

[0128] The sensor board 72 is mounted with a circuit for detecting the rotational position (angle) of the encoder disk, as well as a circuit for supplying power to the coils 44 and 45. The circuit for supplying power includes a circuit that connects one end of the coils 44, 45 together, and this circuit has a through hole 726 into which the other side 4964 of the terminal support portion 494 provided on the bobbin having the coils 44, 45 is inserted and connected to the circuit.

[0129] By inserting the other side portions 4964 into the through holes 726, the coils 44 and 45 have one end connected to each other via the sensor substrate 72, and the other end connected to a circuit for inputting and outputting power supply.

[0130] This allows a circuit to be constructed that supplies power to the coils 44 and 45 simply by assembling the drive unit 4 and attaching the sensor board 72 to the top cover 60, while also preventing unwanted external substances such as foreign matter from entering the sensing portion of the sensor section 70.

[0131] Furthermore, the other side 4964 of the terminal support portion 494 of the coil body is directly connected to the sensor board 72, so the sensor portion and the terminals for driving the actuator (motor portion) can be integrated and wired onto a single board, the sensor board 72. That is, the board used in the rotary reciprocating drive actuator 1 can be mounted with a circuit for the sensor as well as a circuit for driving the actuator, allowing the board to be shared, and the connectors for connecting the actuator itself to external devices to be standardized.

[0132] Next, the operation of the rotary reciprocating actuator 1 will be described with reference to Figures 3 and 20. Figure 20 is a diagram illustrating the operation of the magnetic circuit of the rotary reciprocating actuator 1.

[0133] The magnetic poles 410a, 410b of the two rod-shaped bodies 411a, 411b of the core body 400 of the core assembly 40 are arranged to sandwich the magnet 32 ​​with an air gap G therebetween. When the coils 44, 45 are not energized, the magnet 32 ​​is held in a neutral position by the magnetic attraction force between the magnet 32 ​​and the rotation angle position holding part 48, as shown in FIG.

[0134] In this neutral position, one of the south pole 32a and north pole 32b of the magnet 32 ​​(the south pole 32a in FIG. 20) is attracted to the rotational angle position holder 48 (see the magnetic spring torque FM in FIG. 20). At this time, the magnetic pole switching units 32c and 32d face the center positions of the magnetic poles 410a and 410b of the core body 400. In addition, the interpole unit 414 attracts the other of the south pole 32a and north pole 32b of the magnet 32 ​​(the north pole 32b in FIG. 20). This allows the magnet 32 ​​to move more effectively to the neutral position.

[0135] When current is applied to the coils 44 and 45, the core body 400 is excited, and the magnetic poles 410a and 410b have polarities according to the direction of current application. For example, as shown in Fig. 20, when current is applied to the coils 44 and 45, a magnetic flux is generated inside the core body 400, and the magnetic pole 410a becomes an N pole and the magnetic pole 410b becomes an S pole.

[0136] As a result, magnetic pole 410a magnetized to an N pole attracts S pole 32a of magnet 32, and magnetic pole 410b magnetized to an S pole attracts N pole 32b of magnet 32. Then, torque in the F direction is generated in magnet 32 ​​around the axis of rotation shaft 13, causing magnet 32 ​​to rotate in the F direction. Accordingly, rotation shaft 13 also rotates in the F direction, and mirror section 12 fixed to rotation shaft 13 also rotates in the F direction.

[0137] Next, when current is applied to coils 44 and 45 in the opposite direction, the flow of magnetic flux generated inside core body 400 becomes the opposite direction to that shown in Fig. 20, and magnetic pole 410a becomes a south pole and magnetic pole 410b becomes a north pole. Magnetic pole 410a magnetized to a south pole attracts north pole 32b of magnet 32, and magnetic pole 410b magnetized to a north pole attracts south pole 32a of magnet 32. Then, torque -F in the opposite direction to the F direction is generated in magnet 32 ​​around the axis of rotation shaft 13, and magnet 32 ​​rotates in the -F direction. Accordingly, rotation shaft 13 also rotates, and mirror unit 12 fixed to rotation shaft 13 also rotates in the opposite direction to that shown in Fig. 20. The rotary reciprocating actuator 1 rotates and reciprocates the mirror section 12 by repeating the above operations.

[0138] In practice, the rotary reciprocating actuator 1 is driven by an AC wave input to the coils 44, 45 from a power supply unit (e.g., corresponding to the drive signal supply unit 103 in FIG. 32). In other words, the direction of current flow through the coils 44, 45 is switched periodically. When the current flow direction is switched, the magnet 32 ​​is urged to return to the neutral position by the magnetic attraction force between the rotation angle position holder 48 and the magnet 32, i.e., the restoring force of the magnetic spring (the magnetic spring torque FM shown in FIG. 20 and its opposite torque, "-FM"). As a result, a torque in the F direction and a torque in the opposite direction to the F direction (-F direction) act alternately on the movable body 10 around the axis. This causes the movable body 10 to be driven to rotate and reciprocate.

[0139] The following briefly describes the driving principle of the rotary reciprocating drive actuator 1. In the rotary reciprocating drive actuator 1 of this embodiment, the moment of inertia of the movable body (movable body 10) is set to J [kg m 2 ], the spring constant in the torsional direction of the magnetic spring (magnetic poles 410a, 410b, rotation angle position holder 48, and magnet 32) is K sp [N·m / rad], the movable body has a resonance frequency F r It vibrates (reciprocating rotation) at [Hz].

[0140]

number

[0141] Since the movable body constitutes the mass part in the vibration model of the spring-mass system, the resonance frequency F of the movable body is applied to the coils 44 and 45. r When an AC wave having a frequency equal to the resonant frequency F of the movable body is input, the movable body is put into a resonant state. r By inputting an AC wave having a frequency substantially equal to the frequency of the movable body, the movable body can be vibrated efficiently.

[0142] Below are equations of motion and circuit equations that show the driving principle of the rotary reciprocating drive actuator 1. The rotary reciprocating drive actuator 1 is driven based on the equation of motion shown in equation (2) and the circuit equation shown in equation (3).

[0143]

number

[0144]

number

[0145] That is, the moment of inertia of the movable body in the rotary reciprocating drive actuator 1, J [kg m 2 ], rotation angle θ(t) [rad], torque constant K t [N·m / A], current i(t) [A], spring constant K sp [N m / rad], damping coefficient D [N m / (rad / s)], load torque T Loss [N·m], etc. can be changed as appropriate within the range that satisfies equation (2). In addition, the voltage e(t) [V], resistance R [Ω], inductance L [H], and back electromotive force constant K e [V / (rad / s)] can be changed as appropriate within a range that satisfies formula (3).

[0146] In this way, the rotary reciprocating actuator 1 is configured with the moment of inertia J of the movable body and the spring constant K of the magnetic spring. sp The resonant frequency F is determined by r When the coil is energized with an AC wave corresponding to the above, a large vibration output can be obtained efficiently.

[0147] <Variation 1> FIG. 21 is a vertical cross-sectional view showing the first modification of the rotary reciprocating actuator, and FIG. 22 is an exploded perspective view of the first modification of the rotary reciprocating actuator.

[0148] In the rotary reciprocating drive actuator 1A of the first modification, 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 retaining portion 14 are different from those of the rotary reciprocating drive actuator 1, but the other configurations are the same. Therefore, the same names with the same functions are given the same reference numerals and their explanations are omitted, and only the differences will be explained.

[0149] In the rotary reciprocating actuator 1A, a main body unit A is formed by attaching a movable body 10A to a base portion 21A, and the rotary reciprocating actuator 1A has a drive unit 4 on a wall portion 211 which is one end of the main body unit 2.

[0150] In comparison with the rotary reciprocating actuator 1, the rotary reciprocating actuator 1A has a preload spring 35 disposed between the bearing 22 and the mirror holder 122.

[0151] The base portion 21A has a pair of wall portions 211A, 212A that stand upright from both ends that are spaced apart in the extension direction of the bottom portion 213. Bearings 22, 23 with flanges arranged on the axially inner side are arranged in the center of each of the wall portions. For example, the bearings 22, 23 are press-fitted into the insertion holes 211Aa, 212Aa from the axially inner side. The rotating shaft 13 is inserted into the bearings 22, 23.

[0152] Further, the stopper portion 15A is shorter than the stopper portion 15 and is attached to the base end portion of the rotary shaft 13 from the outside of the base portion 21A.

[0153] The stopper 14 is fitted into the fitting groove 133A inside the wall portion 212A at the end of the rotary shaft 13A that passes through the wall portion 212A.

[0154] In this configuration, when a load is applied to the rotary shaft 13A from the axial outside of the stopper 15A, in other words, from the base end (one end 131) side of the rotary shaft 13A, the position of the rotary shaft 13A is maintained by the stopper 15A. Also, even when the force of the preload spring 35 is applied, the position is maintained by the stopper 14, and the function of the preload spring 35 in the rotary reciprocating drive actuator 1 is similar, and the same effect can be obtained.

[0155] That is, movable body 10A is configured such that an outward preload is applied to both sides in the axial direction, and preload spring 35 is disposed near the movable object. As a result, preload spring 35 is disposed in the dead space of rotating shaft 13 that is installed between a pair of walls (side walls) 211A, 212A of base portion 21A, and therefore, compared to a configuration in which preload spring 35 is disposed inside drive unit 4, it is possible to reduce the height and size.

[0156] <Variation 2> Fig. 23 is an external perspective view of the rotary reciprocating drive actuator variation 2, Fig. 24 is a perspective view of the main unit of the rotary reciprocating drive actuator variation 2. Fig. 25 is a front view showing the main configuration of the drive unit in the rotary reciprocating drive actuator variation 2, and Fig. 26 is a perspective view of the rotary reciprocating drive actuator variation 2 that is attached to a product.

[0157] The rotary reciprocating actuator 1B shown in FIGS. 23 to 26 has the same function as the rotary reciprocating actuator 1, and also has a fixing hole 215 as an actuator fixing portion for fixing to a fixing base portion 800 of the body of the product.

[0158] The fixing hole 215 is provided, for example, in a wall portion 211B of a base portion 21B in a fixed body 20B having substantially the same function as the fixed body 20. The fixing hole 215 is formed in flange-shaped protruding side portions 2110 on both sides that protrude in a direction perpendicular to the axial direction from a portion of the wall portion 211B where the drive unit 4 is fixed. Note that the fixing hole 215 may be provided on one side of the protruding side portions 2110 on both sides.

[0159] In a front view, the both protruding side portions 2110 are arranged adjacent to each other on the left and right sides of the drive unit 4. In the bottom cover 50 of the drive unit 4, the both protruding side portions 2110 are arranged outward from both sides (the outer left and right sides in a front view) of the mounting portion 522 that is attached to the wall portion 211B via the fastening member 81.

[0160] Counterbore portions 2112 are provided around the fixing holes 215 on the rear surfaces of the protruding side portions 2110, and are formed so that the heads of the fastening members 87 do not protrude in the axial direction from the wall portions 211B.

[0161] The wall 211B has a positioning notch 217 and a positioning hole 216 that enable positioning when attaching the drive unit 4 to the housing of the product (for example, the fixed base 800). The positioning notch 217 is provided on the outer edge of the wall 211B, for example, in the center of one of the protruding sides 2110 on both sides. The wall 211B has a positioning hole 216 formed symmetrically to the positioning notch 217 with respect to the center.

[0162] When this rotary reciprocating drive actuator 1B is attached to the body of a product, the rotary reciprocating drive actuator 1B is fixed to a fixed base part 800 provided on the body side (for example, as a part of the body).

[0163] The fixed base 800 is configured as a U-shape having fixed walls 804, 806 that stand facing each other at a distance from each other. The rotary reciprocating drive actuator 1B is fixed to the fixed base 800 so that the drive unit 4 is located inside this U-shape. The rotary reciprocating drive actuator 1B is fixed with the axial direction parallel to the standing direction of the fixed base 800, with both side protrusions 2110 of the wall 211B abutting against the upper end surfaces of the fixed walls 804, 806, and fastened by fastening members 87 inserted through the fastening holes 215. In addition to fastening holes 807 into which the fastening members 87 are inserted, positioning protrusions 808 that are inserted into the positioning holes 216 are provided on the upper end surfaces of the fixed walls 804, 806.

[0164] When attaching the rotary reciprocating drive actuator 1B to the fixed base 800, the positions of both are adjusted by inserting a positioning protrusion 808 parallel to the axis into a positioning hole 216 parallel to the axis and rotating it around this. A rod or the like is inserted into the positioning cutout 217 to further adjust the position, and then the fixing hole 215 and the fastening hole 807 are aligned and the fastening member 87 is inserted through both to fix them.

[0165] The axial direction is the same as the axial direction of the bearing 22 resulting from the position of the mirror portion 12, so the rotary reciprocating drive actuator 1B can be positioned and fixed to the fixed base portion 800 with high precision.

[0166] Furthermore, a positioning notch 217, a positioning hole 216, and a fixing hole 215 are provided in a wall 211B that holds the mirror unit 12. These are used to fix the wall 211B to the fixed base 800. The wall 211B is formed with an insertion hole 211a (coaxial with the insertion hole 211b) that serves as an insertion hole for the bearing 22 of the rotation shaft 13 to which the mirror holder 122 is fixed and that determines the mirror position. Therefore, positioning and fixing to the fixed base 80 is possible on the same processed surface as the insertion hole 211a that determines the mirror position, and fixing can be performed with high precision.

[0167] If the actuator fixing portion is provided on the drive unit 4 side, it can be fixed to the product body, i.e., the fixing base portion 800, near the center of gravity of the rotary reciprocating drive actuator, thereby effectively suppressing external vibrations or impacts. The actuator fixing portion may also be provided on the top cover of the drive unit 4.

[0168] <Variation 3> Fig. 27 is an external perspective view of the rotary reciprocating actuator of Variation 3, Fig. 28 is an external perspective view of the top cover of the rotary reciprocating actuator of Variation 3. Also, Fig. 29 is a perspective view showing the rotary reciprocating actuator of Variation 3 that is attached to a product.

[0169] 27 and 28, a rotary reciprocating drive actuator 1C of Modification 3 is different from the rotary reciprocating drive actuator 1 only in that it has a top cover 60C, and the other components are the same. Therefore, the same components as those of the rotary reciprocating drive actuator 1 are given the same reference numerals and their explanations will be omitted.

[0170] The rotary reciprocating actuator 1C shown in FIGS. 27 and 28 has a top cover 60C provided with a fixing hole 625 as an actuator fixing portion.

[0171] Top cover 60C has rectangular plate-shaped top cover main body 62C provided with protruding side portions 6210 on both sides that protrude in a direction perpendicular to the axial direction, similar to wall portion 211B of Modification 2. Protruding side portions 6210 on both sides are provided with fixing holes 625 that extend parallel to the axial direction. Like top cover 60, top cover 60C has a concave sensor housing portion 65 on its front surface and a recessed portion on its back surface, which have the same functions as the sensor housing portion and recessed portion of top cover 60, respectively.

[0172] Counterbore portions 6212, which are formed by cutting out the periphery of the fixing hole 625, are provided on the rear surface of each of the protruding side portions 6210 of the top cover main body 62C and are continuous with the fixing hole 625. These counterbore portions 6212 prevent the head of the fastening member 87 (see FIG. 29) inserted into the drive unit 4C from protruding in the axial direction from the wall portion 211B. A through-hole 66 and a bobbin engagement hole 67 are provided in the sensor housing portion 65, and the sensor housing portion 65 is covered by the sensor board 72.

[0173] Furthermore, top cover main body 62C is provided with a positioning hole 626 and a positioning cutout 627 that have the same functions as wall portion 211B. Positioning cutout 627 is provided on the outer edge, for example, in the center of one side protrusion 6210. In top cover main body 62C, positioning hole 626 is formed at a position symmetrical to positioning cutout 627 with respect to the center.

[0174] In this rotary reciprocating drive actuator 1C, fixing hole 625, which is the actuator fixing portion, is provided in top cover 60C of drive unit 4C. As a result, rotary reciprocating drive actuator 1C is fixed by inserting fastening member 87 parallel to the axial direction into fixing hole 625 and fastening hole 807, and tightening it, to a pair of fixing walls 804, 806 in the recessed portion of fixing base part 800, as shown in Figure 29. At this time, since the drive unit 4C is fixed to the fixed base portion 800 by the top cover 60C, it can be easily and accurately fixed between the fixed wall portions 804 and 806 without inserting the drive unit 4C.

[0175] Furthermore, since the drive unit 4C is fixed to the fixed base 800, the rotary reciprocating drive actuator 1C is fixed to the fixed base 800 at a position close to its center of gravity, so that disturbance vibrations and shocks can be effectively attenuated.

[0176] The top cover 60C is provided with a positioning hole 626 and a positioning cutout 627 that penetrate the top cover 60C in the axial direction. By inserting a positioning protrusion 808 on the upper end surface of the fixed wall portion 806 into the positioning hole 626 and inserting another positioning protrusion into the positioning cutout 627, it is possible to position both the parts before fixing them together.

[0177] Furthermore, when attaching rotary reciprocating actuator 1C to fixed base 800, positioning protrusion 808 parallel to the axis can be inserted into positioning hole 626 parallel to the axis. Rotary reciprocating actuator 1C can then be rotated around this to adjust the position of rotary reciprocating actuator 1C and fixed base 800, and a rod or the like can be inserted into positioning cutout 627 to adjust the position even more accurately.

[0178] <Variation 4> FIG. 30 is an external perspective view of the bottom cover of the rotary reciprocating actuator of Modification 4, and FIG. 31 is a perspective view showing Modification 4 of the rotary reciprocating actuator attached to a product.

[0179] In the rotary reciprocating drive actuator 1D of the fourth modification, a fixing hole 525, which is an actuator fixing portion, is provided in a bottom cover 50D of the drive unit 4. The rotary reciprocating drive actuator 1D differs from the rotary reciprocating drive actuator 1 only in the configuration of the bottom cover 50D, and the other components are similar. Therefore, only the differences will be described, and similar components will be given the same names and symbols and will not be described again.

[0180] As shown in Figure 30, the bottom cover 50D is similar to the bottom cover 50, and has a rectangular plate-shaped cover body 52 with an opening 53 in the center, and protruding side portions 5210 on both sides in a direction perpendicular to the axial direction, similar to the wall portion 211B of variant example 2.

[0181] The protruding side portions 5210 on both sides have fixing holes 525 that protrude outward beyond the drive unit 4 and extend parallel to the axial direction. Similar to the bottom cover 50, the bottom cover 50D has positioning protrusions (not shown) protruding from the back surface of the bottom cover 50. The positioning protrusions engage with the recesses 218 in the wall portion 211 of the base portion 21 to determine position.

[0182] As shown in Figure 31, the rotary reciprocating drive actuator 1D having this bottom cover 50D is fixed by inserting a fastening member 87 parallel to the axial direction into a pair of fixed wall portions 804, 806 in the recessed portion of the fixed base portion 800, a fastening hole 525, and a fastening hole 807, and tightening the fastening member 87.

[0183] At this time, since the bottom cover 50D is fixed to the fixed base portion 800, the top cover 60 and core assembly 40 of the drive unit 4C can be positioned between the fixed wall portions 804 and 806 and easily and accurately fixed in a shortened axial state.

[0184] Furthermore, since the drive unit 4D is fixed to the fixed base 800, the rotary reciprocating drive actuator 1D is fixed to the fixed base 800 at a position close to its center of gravity, thereby effectively attenuating external vibrations and impacts.

[0185] In particular, the rotary reciprocating actuator 1D is fixed to the fixed base 800 by a bottom cover 50D disposed between the core assembly 40 and the mirror section 12. This allows the actuator 1D to be fixed to the fixed base 800 at the center of gravity between the core assembly 40 and the mirror section 12, thereby enabling stable holding.

[0186] The bottom cover 50D is provided with a positioning hole 526 and a positioning cutout 527 that penetrate the bottom cover 50D in the axial direction. This allows a positioning protrusion 808 on the upper end surface of the fixing wall 806 to be inserted into the positioning hole 526, and another positioning protrusion 808 to be inserted into the positioning cutout 527. In this way, the two can be accurately positioned before being fixed together via the fastening hole 807 and the fixing hole 525.

[0187] Furthermore, when attaching the rotary reciprocating drive actuator 1C to the fixed base 800, the positions of both can be adjusted by inserting the positioning protrusion 808 parallel to the axis into the positioning hole 216 parallel to the axis and rotating it around this. In addition, by inserting a rod or the like into the positioning cutout 217, the position can be adjusted even more accurately.

[0188] FIG. 32 is a block diagram showing the configuration of the main parts of a scanner system 100 using the rotary reciprocating actuator 1. As shown in FIG.

[0189] The scanner system 100 is one of the rotary reciprocating actuators 1, 1A to 1D, and in addition to these rotary reciprocating actuators 1, 1A to 1D, has a laser emission unit 101, a laser control unit 102, a drive signal supply unit 103, and a position control signal calculation unit 104.

[0190] The laser emitting unit 101 includes, for example, an LD (laser diode) serving as a light source, and a lens system for converging the laser light output from the light source. The laser control unit 102 controls the laser emitting unit 101. The laser light emitted from the laser emitting unit 101 is incident on a mirror 121 of the rotary reciprocating actuator 1.

[0191] The position control signal calculation unit 104 references the angular position of the rotating shaft 13 (mirror 121) acquired by the angle sensor unit 70 and the target angular position, and generates and outputs a drive signal that controls the rotating shaft 13 (mirror 121) to be at 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 rotating shaft 13 (mirror 121) and a signal indicating the 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.

[0192] Based on the position control signal, the drive signal supply unit 103 supplies a drive signal to the coils 44, 45 of the rotary reciprocating actuator 1 so that the angular position of the rotary shaft 13 (mirror 121) becomes a desired angular position. This enables the scanner system 100 to emit scanning light from the rotary reciprocating actuator 1 to a predetermined scanning area.

[0193] <Summary> As described above, the rotary reciprocating drive actuator 1 according to this embodiment has a movable body 10 having a rotary shaft (shaft) 13 to which a mirror (movable object) is connected, and a magnet 32 ​​fixed to the rotary shaft 13. The magnet 32 ​​is a ring-shaped magnet with south poles 32a and north poles 32b arranged alternately in the circumferential direction on its outer circumferential surface. In addition, the rotary reciprocating drive actuator 1 has a fixed body 20 having a core assembly 40.

[0194] A preload spring 35 that applies a preload to the bearing 22 is fitted onto the rotating shaft 13. The preload spring 35 is disposed, for example, on the rotating shaft 13, between the magnet 32 ​​(specifically, the annular receiving portion 37 that is fixed to the rotating shaft 13 integrally with the magnet 32) and the bearing 22.

[0195] Preload spring 35 prevents direct impact from being applied to magnet 32 ​​by abutting annular receiving portion 37 and bearing 22 at both ends thereof. In other words, annular receiving portion 37 functions as a stopper, and even if preload spring 35 receives and absorbs an external impact, it prevents unnecessary load from being applied to magnet 32, thereby improving drive reliability.

[0196] Furthermore, because a stable preload is applied to the bearing (for example, a ball bearing) 22, the rotating shaft 13 can rotate stably and with high reliability with little sliding relative to the bearing 22. In this way, the rotary reciprocating drive actuator 1 has high rotation accuracy, improves the rigidity of the shaft, and can perform driving with little sliding and high reliability.

[0197] Furthermore, the preload spring 35 is disposed inside the rotary reciprocating drive actuator 1 and is not affected by anything outside the rotary reciprocating drive actuator 1. This allows for quantitative control in the design of the rotary reciprocating drive actuator, enabling the design of a stable preload.

[0198] Additionally, the sensor substrate 72 is located outside the drive unit 30 (core body 400, magnet 32) and, together with the magnet 32, covers the periphery of the detection unit (encoder disk) of the sensor component. This allows the sensor substrate 72 to prevent contamination of the sensor housing 65 and, ultimately, the air gap G between the magnet and core body 400. In this way, foreign matter is prevented from entering the air gap G, preventing malfunctions and enabling optimal driving.

[0199] Furthermore, since the magnet 32 ​​is placed inside the drive unit 4 of the rotary reciprocating drive actuator, no magnet is placed on the outside, and the magnetic flux is not distributed to the outside (front side), which reduces leakage magnetic flux to the front side, and the actuator can be placed even if there are magnetically sensitive products nearby.

[0200] Since the core assembly 40 of the drive unit 4 is in the shape of a rectangular frame block, even in a space where the installation space for the core assembly 40 is limited, for example, the rectangular area (area viewed in the axial direction) of the wall surface of the wall portion 211 of the base portion 21, it can fit into that rectangular area, ensuring sufficient magnetic path length and enabling high-amplitude driving of the movable body 20.

[0201] Furthermore, when performing maintenance on the angle sensor unit 70, simply removing the fastening member 84 exposes the sensor components, which are expensive parts, to the outside in the event of a malfunction, allowing for easy repair or replacement.

[0202] Furthermore, when the sensor section is an optical sensor, it is possible to prevent light from interfering with the sensor housing section 65 without using a separate light-blocking member.

[0203] When fixing the drive unit 4 to the main unit 2, if the rotation axis 13 is used as the reference, it is desirable to fix it at a position where the dimensions can be determined from that reference. Also, when fixing the rotary reciprocating drive actuator to the product housing with the axis vertical, the rotary reciprocating drive actuator can be assembled and attached by positioning and fixing from a direction parallel to the axis. This allows for highly accurate positioning and fixing with fewer additional dimensions than when assembling in a direction different from the axis direction.

[0204] 4, 11, and 13, in the drive unit 4 of the rotary reciprocating drive actuator 1, the through-hole into which the fastening member 86 that fastens the bottom cover 50, core assembly 40, and top cover 60 is inserted and the through-hole into which the fastening member 81 that fastens the top cover 60 and sensor board 72 is inserted are through-holes that extend parallel to the axial direction and have the same axis. In other words, the sensor board 72 is fastened using the same screw hole (through-hole) that was used to secure the drive unit 4, so no additional screw hole is required to secure the sensor board 72, which reduces costs.

[0205] An impact-resistant bushing 39 is arranged adjacent to the rotary encoder and other sensor components. As a result, even if the rotary shaft 13 vibrates due to a disturbance such as an impact received by the rotary reciprocating drive actuator 1, the impact is received by the bushing 39, preventing the sensor components from being affected by the impact.

[0206] Furthermore, a gap (clearance) 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 rotating shaft 13. In this case, sliding between the bushing 39 and the rotating shaft 13 is eliminated, ensuring shock resistance. Furthermore, if the bushing 39 and the rotating shaft 13 are configured to slide, shocks are reliably received, preventing the impact on the sensor portion and damping unnecessary vibrations of the movable body, thereby achieving noise reduction.

[0207] The movable object is the mirror portion 12 (particularly the mirror 121) that reflects the scanning light. This allows the rotary reciprocating actuator 1 to be used as a scanner that performs optical scanning.

[0208] Furthermore, in the ring-shaped magnet 32 ​​of the rotary reciprocating drive actuators 1, 1A to 1D of this embodiment, the magnetic pole switching sections 32c, 32d are configured as U-shaped grooves formed in one end surface 322 as shown in Fig. 33, but they do not have to be configured as U-shaped grooves. The magnetic pole switching sections may be configured in any way as long as they indicate the positions where the magnetic poles change in the magnet 32. Modified examples of the magnet 32 ​​will be described with reference to Figs. 33 to 37.

[0209] Figures 33 to 37 show modified examples 1 to 4 of the magnet in the rotary reciprocating drive actuators 1, 1A to 1D. Note that Figures A and B in Figures 34 to 36 show a front view and a right side view, respectively, of the magnet as a modified example, and Figure 37 shows a core assembly of a rotary reciprocating drive actuator having modified example 4.

[0210] 34 to 36 are formed on a ring having an opening 321 in the center through which the rotation shafts 13 and 13A are inserted. The magnet 320 shown in Fig. 34 has protruding magnetic pole switching portions 32e and 32f integrally formed on the diameter portion of one end face 322.

[0211] The magnetic pole switching positions of the magnet 320 can be determined by the shape of the magnet 320 using the magnetic pole switching sections 32e and 32f.

[0212] Furthermore, magnet 320A shown in FIG. 35 has magnetic pole switching portion 32g, which has a V-shaped cross section instead of a U-shaped cross section, on end surface 322 of the ring-shaped main body.

[0213] The magnetic pole switching positions of the magnet 320 can be determined by the shape of the magnet 320A using the magnetic pole switching sections 32g and 32f.

[0214] Here, it is desirable that the assembly precision of the magnetic pole directions of magnets 320, 320A be such that they are arranged in a well-balanced manner in accordance with the angle reference of mirror section 12, which is the movable object, and the angle reference of angle sensor 76. If there is a deviation in each angle reference, the characteristics will change depending on the rotation angle of rotating shaft 13, which will cause a problem of performance variation.

[0215] In contrast to this, in this embodiment, the magnetic pole switching portions 32c to 32h of the magnets 32, 320, 320A are formed in a U-shape, protruding shape, V-shape or the like, and the magnets 32, 320, 320A have a shape that is concave and convex in the magnetizing direction.

[0216] Therefore, by using a positioning jig having pins corresponding to U-shapes, protruding shapes, V-shapes, etc., other parts can be attached or the rotary reciprocating drive actuator can be assembled using these magnetic pole switching sections 32c, 32d, 32e, 32f, 32g, and 32h as reference points.

[0217] That is, the unevenness can be used as a reference to adjust the positional relationship of the components fixed to the rotary shaft 13 when assembling or maintaining the rotary reciprocating drive actuator 1. The angular accuracy of the mirror unit 12, the angle reference of the angle sensor unit 70, and the magnetic pole reference of the magnet 32 ​​can be easily aligned, making it easy to achieve high-precision assembly.

[0218] Furthermore, if the magnet 32 ​​is configured so that the concave and convex portions are arranged in the magnetization direction, the influence on the opposing magnetic poles 410a, 410b on the outer peripheral surface and the rotation angle holding unit (magnetic spring) 48 is small, the influence on torque is small, and there is no variation in the magnetic attraction force characteristics of the rotation angle holding unit 48.

[0219] 36 has a flat surface 328 formed by cutting out a portion of the outer circumferential surface 326. The flat surface 328 is provided as part of the outer circumferential surface of one of the different magnetic poles of the magnet 320B.

[0220] For example, when core assembly 40B having magnet 320B is provided in rotary reciprocating drive actuator 1, magnet 320B is arranged so that flat surface 328 is formed on magnetic pole 32b opposite magnetic pole 32a that faces rotation angle position holder 48 shown in FIG. 37. This flat surface 328 faces the curved surface of inter-pole section 414. Specifically, when magnet 320B is in the reference position, flat surface 328 is arranged so that the center of its circumferential (horizontal) length and the circumferential (horizontal) center of inter-pole section 414 are positioned on a line that passes through the center of opening 321 (rotation axes 13, 13A) and is perpendicular to flat surface 328.

[0221] In magnet 320B, for example, if flat surface 328 is positioned on the side of rotation angle retaining portion 48 or core (magnetic pole 410), the flow of magnetic flux generated will be unbalanced because this is the only flat portion of magnet 320B, which may affect the magnetic circuit characteristics or degrade performance.

[0222] In contrast to this, in the present embodiment, flat surface 328 of magnet 320B is configured to be located on the opposite side of rotation axis 13 from rotation angle holder 48 when in a non-energized state, for example, when in the reference position. This allows flat surface 328 to generate a magnetic attractive force with commutating pole unit 414 without affecting rotation angle holder 48, that is, without causing an imbalance in torque generation.

[0223] The invention made by the inventor has been specifically described above based on an embodiment, but the present invention is not limited to the above embodiment and can be modified within the scope of the gist thereof.

[0224] For example, in the embodiment, the movable object is the mirror unit 12, but the movable object is not limited to this. The movable object may be, for example, an imaging device such as a camera.

[0225] Furthermore, for example, in the embodiment, the case where the rotary reciprocating drive actuator 1 is resonantly driven has been described, but the present invention can also be applied to the case where it is non-resonantly driven.

[0226] The configuration of the drive unit 4 is not limited to that described in the embodiment. For example, the core may have magnetic pole portions that are excited by energizing the coil to generate polarity, and when the rotating shaft is attached to the fixed body, the magnetic pole portions and the outer circumferential surface of the magnet may face each other across an air gap. The coil may also have a configuration that generates a magnetic flux that is preferably directed from one side of the magnetic pole portions of the core to the other side when energized.

[0227] Furthermore, the rotation angle position retaining unit 48 provided in the fixed body 20 is configured to be attached to the second core 42, but this is not limiting and the rotation angle position retaining unit 48 may be configured to be provided in another component of the fixed body 20. In these cases, the rotation angle position retaining unit 48 may be accommodated in the second core 42.

[0228] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Industrial Applicability]

[0229] The present invention is suitable for, for example, LiDAR devices and scanner systems. [Explanation of symbols]

[0230] 1, 1A, 1B, 1C, 1D Rotary and reciprocating drive actuator 2 Main unit 4, 4C, 4D drive units 10, 10A movable body 12 Mirror section 13, 13A Rotating shaft 14 Stopper 15, 15A stopper part 20 Fixed body 21, 21A, 21B base 22, 23 Bearings 30 Drive unit 32, 320, 320A, 320B magnets 32a, 32b, 410a, 410b magnetic pole 32c, 32d, 32e, 32f, 32g, 32h Magnetic pole switching section 35, 350 Preload spring (preload applying part) 37 Annular receiving part 39 Bush 40, 40B core assembly 41 First Core 42 Second Core 43 Third Core 44, 45 coils 46, 47 Bobbin 48 Rotation angle position holding unit 49 Coil body 50, 50D bottom cover 52 Cover body 53, 321 opening 54, 55, 66 Through holes 56, 216, 526, 626 Positioning holes 57 Position adjustment hole 58 Core holding protrusion 59, 808 Positioning protrusion 60, 60C top cover 62, 62C top cover body 64 Peripheral wall section 65 Sensor storage compartment 67 Bottle engagement hole 70 Angle sensor unit 72 Sensor board 74 Encoder disk (detected part) 76 Light Sensor (Sensor) 81, 84, 86, 87 Fastening members 100 Laser System 101 Laser emission unit 102 Laser control unit 103 Drive signal supply unit 104 Position control signal calculation unit 121 Mirror 122 Mirror Holder 122a, 211a, 211b, 211Aa, 212a, 211Aa, 212Aa Insertion holes 131 One end 132 Other end 133, 133A fitting groove 211, 211A, 211B, 212, 212A Wall section 213, 213A, 213B bottom 215, 525, 625 fixed hole 217, 527, 627 Positioning notch 218 recess 212a Insertion hole 222, 232 Bearing body 224, 234 flange 322 End face 326 Outer surface 328 Flat surface 400 Core Body 411, 411a, 411b Rod-shaped body 412 Connecting edge 413, 413a, 413b side part 414 Interpolator 414 Reinforcement 492 Bobbin section 494 Terminal support part 496 terminals 522 Mounting part 541, 2112, 6212 Counterbore 621 Concave part 726 through hole 800 Fixed base 804, 806 Fixed wall section 807 Fastening hole 2110, 5210, 6210 protruding parts on both sides 4964 Other side 4962 Side

Claims

1. a movable body having a shaft portion with a magnet fixed to its outer periphery and capable of reciprocating rotation around the shaft; a base portion having a pair of walls that rotatably support the shaft portion via a bearing; a core assembly including a core body having a plurality of magnetic poles facing the outer periphery of the magnet so as to sandwich the magnet, and a coil body wound around the core body, which generates a magnetic flux that interacts with the magnet when current is applied, thereby causing the movable body to reciprocate; a preload applying portion that is fitted onto the shaft portion and applies a preload to the bearing; and An annular receiving portion is fixed to the shaft portion between the bearing and the magnet, the annular receiving portion being adjacent to the magnet, the preload applying portion is disposed between the annular receiving portion and the bearing and presses the annular receiving portion and the bearing along the shaft portion; Rotary reciprocating drive actuator.

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

2. The rotary reciprocating drive actuator according to claim 1.

3. the bearing is a ball bearing having a flange that axially engages with each of the pair of wall portions, the preload applying portion is disposed so as to bias the bearing of one of the pair of wall portions from the flange side of the bearing in an engagement direction with the one wall portion.

2. The rotary reciprocating drive actuator according to claim 1.

4. The preload applying portion is a cylindrical coil spring or a wave spring.

2. The rotary reciprocating drive actuator according to claim 1.

5. The number of poles of the plurality of magnetic poles is two.

2. The rotary reciprocating drive actuator according to claim 1.

6. the movable object is a mirror that reflects the scanning light; 3. The rotary reciprocating actuator according to claim 2.

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