Rotary and reciprocating actuator

Abstract

To preferably drive a movable object with a high amplitude.SOLUTION: A rotation reciprocation drive actuator includes: a mobile body that includes a shaft part to which a mobile object is connected on one end part side and a magnet fixed to the shaft part on the other end part side, and is supported around an axis to be reciprocation rotatable; a base part that includes a pair of wall parts that rotatably supports the shaft part via a bearing on the one end part side, and is arranged so as to nip the mobile object; a core assembly having a core body that includes a plurality of magnetic poles opposite to an outer periphery of the magnet so as to nip the magnet, a coil body that is wound around the core body, and makes the mobile body rotate in reciprocation by generating a magnetic flux that mutually acts with the magnet by power conduction, and a magnet position holding part that regulates a reference position of the reciprocation rotation by generating a magnetic suction force between itself and the magnets, and is attached to the other wall part of the pair of wall parts; and a sensor substrate which is attached to one wall part of the pair of wall parts, to which a sensor for detecting a rotation angle of the shaft part is mounted, and in which the sensor is arranged from the one end part side to the one wall part toward the one wall part side.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, as described in Patent Document 1, the rotary reciprocating actuator is provided with an angle sensor that detects the rotation angle of the rotary shaft connected to the mirror. The scanning accuracy of the scanner largely depends on the detection accuracy of this angle sensor. To improve the detection accuracy of the angle sensor, it is necessary to adjust the assembly position of the angle sensor with high precision so that the relative relationship between the angle sensor and other components of the rotary reciprocating actuator, such as the mirror, is fixed.

[0007] If the angle sensor is not located near the bearing that supports the rotating shaft, it will be affected by shaft wobble, making it difficult to accurately detect the rotation angle of the rotating shaft. Also, if the angle sensor is located close to the motor, there is a problem that it is difficult to perform appropriate measurements due to the influence of electromagnetic noise and heat from the motor.

[0008] The present invention has been made in consideration of the above points, and provides a rotary reciprocating actuator that can drive a movable object more suitably with high amplitude. [Means for solving the problem]

[0009] One embodiment of the rotary reciprocating drive actuator of the present invention comprises: a movable body having a shaft portion to which a movable object is connected at one end side and a magnet fixed to the shaft portion at the other end side, the movable body being supported so as to be rotatable back and forth around the shaft; a base portion that rotatably supports the shaft portion via a bearing at the one end side and has a pair of walls that are arranged to sandwich the movable object; a core body having a plurality of magnetic poles facing the outer periphery of the magnet so as to sandwich the magnet; 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 magnet position holding portion which generates a magnetic attraction force between itself and the magnet and determines a reference position for the reciprocating rotation; No. 1 a core assembly attached to the wall of the Of the pair of walls No. 2a sensor attached to the wall of the a sensor substrate to be mounted; and a recessed sensor placement portion through which the one end portion is inserted and which opens to the outside is provided on the outer surface of the second wall portion; The sensor substrate is disposed in the sensor arrangement portion so as to close the sensor arrangement portion with the sensor facing the second wall portion. Adopt the configuration. [Effects of the Invention]

[0010] According to the present invention, the rotation of the shaft connected to the movable object can be accurately detected, so that the movable object can be driven more suitably with high amplitude. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an external perspective view of a rotary reciprocating actuator according to an 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] An enlarged view of the preload spring. [Figure 6] FIG. 10 is a diagram showing a wave spring, which is a modified example of the preload spring. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] Exploded view of the coil body. [Figure 10] FIG. 4 is a perspective view showing a state in which coils are connected in a coil body. [Figure 11] FIG. [Figure 12] FIG. 2 is an external perspective view of an angle sensor unit in the rotary reciprocating actuator. [Figure 13] FIG. [Figure 14] FIG. [Figure 15]FIG. 2 is a diagram illustrating the operation of a magnetic circuit of a rotary reciprocating drive actuator. [Figure 16] FIG. 10 is an external perspective view of a first modified example of the rotary reciprocating actuator. [Figure 17] FIG. 10 is a longitudinal cross-sectional view showing a first modified example of the rotary reciprocating actuator. [Figure 18] FIG. 10 is an exploded perspective view of a first modified example of the rotary reciprocating drive actuator. [Figure 19] FIG. 10 is a perspective view of a wall portion on the front surface side of the rotary reciprocating actuator according to Modification 1. [Figure 20] FIG. 10 is an exploded perspective view of the front side of the sensor unit disposed on the wall portion on the same end side. [Figure 21] FIG. 1 is a diagram showing the configuration of a main part of a scanner system using a rotary reciprocating actuator. [Figure 22] 22A and 22B are a front view and a right side view of a first modified example of a magnet. [Figure 23] 23A and 23B are a front view and a right side view of a modified example 2 of the magnet. [Figure 24] 24A and 24B are a front view and a right side view of a third modified example of the magnet. [Figure 25] 25A and 25B are a front view and a right side view of a fourth modified example of the magnet. [Figure 26] FIG. 10 is a diagram showing a core assembly of a rotary reciprocating drive actuator having magnet variant 4. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] 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.

[0014] 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.

[0015] The rotary reciprocating actuator 1 is broadly composed of a movable body 10, a base section 21 that rotatably supports the movable body 10 and has an angle sensor section 70 attached thereto, and a drive unit 4 that drives the movable body 10 to rotate back and forth relative to the base section 21. The base section 21 and drive unit 4 form a fixed body 20 that supports the movable body 10 to rotate back and forth.

[0016] 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.

[0017] 1, in the rotary reciprocating drive actuator 1, a main body unit 2 having a movable body 10 mounted on a base portion 21 and a drive unit 4 are joined by a fastening member 81. Note that the fastening member 81 may be any member that can fasten the main body unit 2 and the drive unit 4 together, and for example, a male screw or bolt or nut may be used.

[0018] 4, 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] 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 standing upright 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 (see FIG. 4). 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 having a larger diameter than the penetrating portions at the opening edges on the axially outer sides of the wall portions 211, 212. 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 insertion holes 211a, 212a of 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 by press-fitting or the like 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 131 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 side 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, so that the mirror unit 12 can be supported more firmly than in a configuration in which the rotating shaft is pivotally supported by a rotating shaft that is cantilevered, and impact resistance and vibration resistance are improved.

[0029] 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.

[0030] A stopper (retaining ring) 14 is fitted into a fitting groove 133 at one end 131 of the rotating shaft 13 that protrudes outside the bearing 23, and this stopper 14 restricts movement of the rotating shaft 13 toward the other end 132. Furthermore, one end 131 of the rotating shaft 13 is inserted through a wall 212 on the one end side, and is connected to an angle sensor unit 70 on the outer surface side of the wall 212. The angle sensor unit 70 detects the angle of the rotating shaft 13, and in the rotary reciprocating drive actuator 1, is arranged so that the mirror unit 12 is sandwiched between the angle sensor unit 70 and the drive unit 4. That is, the angle sensor unit 70 is spaced apart from the magnetic circuit of the drive unit 4 and is arranged near the bearing 23. The angle sensor unit 70 will be described in detail later.

[0031] 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.

[0032] 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.

[0033] The stopper portion 15 prevents the rotary shaft 13 from slipping out of the bearing 23 toward one end in the axial direction, that is, toward the outside, via the mirror portion 12 .

[0034] 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.

[0035] 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.

[0036] 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 .

[0037] In the rotating shaft 13, a preload spring 35, an annular receiving portion 37, and a magnet 32 ​​are arranged in this order from the wall portion 211 side at a portion that protrudes from the wall portion 211 toward the other end portion 132 side.

[0038] The preload spring 35 expands and contracts in the axial direction to bias the bearing 22 in the axial direction. The preload spring 35 is, for example, as shown in FIG. 5, 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.

[0039] 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.

[0040] The preload spring 35 applies a constant preload to the bearing 22. By applying a constant preload to the bearing 22, the preload spring 35 absorbs load fluctuations and expansion and contraction of the rotating shaft 13 due to temperature differences between the rotating shaft 13 and the base portion 21 during rotation, resulting in less fluctuation in the amount of preload and 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, allowing for faster rotational drive and preventing axial vibration compared to a fixed-position preload.

[0041] 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.

[0042] 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.

[0043] The annular receiving portion 37 receives one end of the preload spring 35, which abuts against the bearing 22 at one end, 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.

[0044] 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.

[0045] The preload spring 35 may be a cylindrical coil spring made by spirally winding a round steel wire, or a wave spring made by spirally or annularly winding a plate-shaped steel wire to create a wave shape, as a spring with a low extension / contraction direction, i.e., a low height as a spring.

[0046] 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, a wave spring as the preloading spring 350 shown in FIG. 6 may be used.

[0047] 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 length of expansion and contraction is short.

[0048] When the lengths L0 of the wall portion 211 and the annular receiving portion 37 are made to correspond to conditions such as a range where L2 < L0 < L1, the preloading spring 350 can change its expansion and contraction length by stacking a plurality of the preloading springs 350 in the direction of the length L2.

[0049] In this way, the preloading springs 35 and 350 can be appropriately changed according to their installation locations or preloading targets to adjust the preloading force, prevent suitable high-speed rotation and axial vibration, and enable stable driving.

[0050] <Drive unit 4> The drive unit 4 shown in FIGS. 2 to 4 and FIG. 7 is provided at one of both axially spaced end portions of the base portion 21 and constitutes a part of the fixed body 20. The drive unit 4 is arranged so as to sandwich the base portion 21 with the angle sensor portion 70 in the axial direction. The drive unit 4 constitutes a drive portion 30 together with the magnet 32 and moves the movable body 10. The drive unit 4 has a bottom cover 50, a core assembly 40, and a top cover 60. The drive unit 4 is formed, for example, in a rectangular parallelepiped shape with a square shape when viewed from the front.

[0051] <Core assembly 40> The core assembly 40 shown in FIGS. 3, 4, and 14 has coils 44, 45, bobbins 46, 47 around which the coils 44, 45 are wound, a core body 400, and a rotational angle position holding portion 48.

[0052] 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.

[0053] <Core Body 400> The core body 400 forms a magnetic circuit including 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 portion 412 and side portion 413), a second core 42 arranged to bridge one end of the side portion 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.

[0054] 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.

[0055] <1st Core 41> The first core 41 includes rod-shaped portions 411 (411a, 411b), a connecting edge portion 412, and a side edge portion 413. The first core 41 has opposing magnetic poles 410a, 410b at its tip end, and each of the rod-shaped portions 411 (411a, 411b) is arranged parallel to one another. A connecting edge portion 412 extending perpendicular to the extension direction of the rod-shaped portions 411 (411a, 411b) is connected to the base end of the rod-shaped portions 411 (411a, 411b). Side edges 413a, 413b protrude perpendicularly from both ends of the connecting edge portion 412. A commutating pole portion 414 is provided on the connecting edge portion 412 between the rod-shaped portions 411a, 411b and extending parallel to the rod-shaped portions 411a, 411b.

[0056] The rod-shaped portion 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.

[0057] The rod-shaped portions 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 portions 411a and 411b on the base end side, so that the coils 44 and 45 are arranged to be wound around the rod-shaped portions 411a and 411b.

[0058] When coils 44, 45 are energized and magnetized, the magnetic poles at the tips of rod-shaped portions 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 portions 411a, 411b, for example.

[0059] The rod-shaped portions 411a, 411b have external dimensions that allow the bobbins 46, 47 to be fitted around the rod-shaped portions 411a, 411b from their respective tip ends. This allows the bobbins 46, 47 to be fitted around the tip ends of the rod-shaped portions 411a, 411b in the direction of extension, i.e., from the tips of the magnetic poles 410a, 410b, and positioned around the base ends of the rod-shaped portions 411a, 411b so as to surround them. The fitted bobbins 46, 47 are each disposed between the side portion 413 and the inter-pole portion 414.

[0060] The connecting side portion 412 constitutes one side of the rectangular core body 400, connects the base ends of the rod-shaped portions 411a and 411b, and is disposed extending in a direction perpendicular to the parallel direction of the rod-shaped portions 411a and 411b.

[0061] The connecting side portion 412 mainly connects the base ends of the rod-shaped portions 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.

[0062] 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.

[0063] 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."

[0064] 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.

[0065] <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 portions 411a and 411b from 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.

[0066] 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.

[0067] A rotation angle position retainer 48 is attached to the second core 42 at the center in the extension direction and at a location facing the magnet 32. Other cores are arranged to be joined to both ends of the second core 42, and the second core 42 is arranged in a position where it and the other cores surround the magnet 32 ​​and the magnetic poles 410a, 410b.

[0068] <3rd Core 43> The third core 43, together with the connecting side portion 412 and side portion 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 .

[0069] 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 portions 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.

[0070] 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 portions 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.

[0071] 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.

[0072] 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 portions 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.

[0073] 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.

[0074] <Magnet 32> The polarity of the magnet 32 ​​is switched at boundary portions 32c and 32d (hereinafter referred to as "magnetic pole switching portions") between the south pole 32a and the north pole 32b. The magnetic pole switching portions 32c and 32d are formed in the shape of grooves extending through the axis on one end surface of the magnet 32. When the magnet 32 ​​is held in the neutral position, the magnetic pole switching portions 32c and 32d directly face the magnetic poles 410a and 410b, respectively. The magnetic pole switching portions 32c and 32d function as references for positioning the components of the rotary reciprocating drive actuator 1 when it is assembled.

[0075] In particular, because the magnet 32 ​​is fixed to the rotation axis 13, a jig can be placed in the axial direction against the grooves of the magnetic pole switching sections 32c and 32d to restrict the rotation of the magnet 32 ​​and adjust and determine the positional relationship between the mirror section 12 and the sensor component. Also, because the rotation axis 13, which is the center of the rotary reciprocating drive actuator 1, can be used as a reference, the dimensions of the other components can be easily set and they can be manufactured with high precision.

[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 portions 411a, 411b of the first core 41, so that the coils 44, 45 are arranged to wind around the rod-shaped portions 411a, 411b. In this way, the coils 44, 45 are arranged adjacent to the magnetic poles at the tip ends of the rod-shaped portions 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] 8 is a perspective view of the coil body, FIG. 9 is an exploded view of the coil body, and FIG. 10 is a perspective view showing the state of connection of the coils 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 portion 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 496 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 76 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 portions 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 (swing), and is the position where the left and right rotations around the axis result in the same rotation angle during reciprocating rotation. When magnet 32 ​​is held in the neutral position, magnetic pole switching portions 32c and 32d of magnet 32 ​​directly face the magnetic poles of rod-shaped portions 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] 11 shows a front perspective view of the bottom cover. 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.

[0103] 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).

[0104] 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.

[0105] 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.

[0106] As shown in FIGS. 7 and 11, 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.

[0107] The core holding projections 58 are provided on the cover body 52 so as to project in the axial direction from positions sandwiching the opening 53, and when combined with the core assembly 40, they fit into the core assembly 40 to position it (see Figures 3 and 4).

[0108] The core holding projections 58 are inserted between the rod-shaped portions 411a, 411b and the side portions 413a, 413b, and prevent leakage of magnetic flux flowing between them.

[0109] 6, a positioning protrusion 59 is provided on the back surface of the bottom cover 50. The positioning protrusion 59 engages with a recess 218 (see FIGS. 2 and 4) formed in the wall portion 211 when the bottom cover 50 abuts against the base portion 21 with their centers aligned.

[0110] 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 2 and 4. 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.

[0111] 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 and 4, the top cover 60 of this embodiment functions as a sensor housing section 65 that houses an optical sensor 76 that detects the rotation angle of the movable body 10, i.e., the rotation shaft 13.

[0112] The top cover 60 has a top cover body 62 that covers the surface on the tip side of the core assembly 40, and a peripheral wall portion 64 that protrudes from the outer peripheral edge of the top cover body 62 toward the other end 132 in the axial direction.

[0113] 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.

[0114] 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.

[0115] The bushing 39 supports the other end 132 of the rotating shaft 13. The bushing 39 is supported by the top cover 60 on the other end 132 side so that the shaft does not wobble when the rotating shaft 13 receives an impact. 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] The top cover 60, the core assembly 40 (core body 400), and the bottom cover 50 are fixed by the fastening member 86 via holes of the same diameter that are continuous in the axial direction, such as the fastening hole 402 and the through-hole 54.

[0120] <Angle sensor part 70> FIG. 12 is an external perspective view of the angle sensor unit in the rotary reciprocating actuator 1, FIG. 13 is an exploded perspective view of the front side of the angle sensor unit, and FIG. 14 is an exploded perspective view of the back side of the angle sensor unit.

[0121] The angle sensor unit 70 is provided on the outer surface 21 a of the wall portion 212 on one end side of the base portion 21 .

[0122] The angle sensor unit 70 detects the rotation angle of the movable body 10 (as well as the mirror unit 12) including the magnet 32 ​​and the rotation axis 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.

[0123] The angle sensor unit 70 may be a magnetic or optical sensor. In this embodiment, the angle sensor unit 70 includes a sensor component, a sensor substrate 72, and a substrate holder 73.

[0124] The sensor components included in the angle sensor unit 70 are, for example, an encoder disk 74 and an optical sensor (sensor) 76 having a light source, a light receiving element, and the like. The optical sensor 76 is mounted on the sensor substrate 72, for example.

[0125] The substrate holder 73 holds the sensor substrate 72 to be attached, and the sensor substrate 72 and the wall 212 form an arrangement space (sensor arrangement portion 701) in which the sensor components are arranged.

[0126] The substrate holder 73 is, for example, a plate-like body having an opening 732 in the center, and is fixed to the outer surface 21a of the wall 212 to form a recessed sensor placement section 701 through which the rotation shaft 13 is inserted. A sensor substrate 72 is attached to the substrate holder 73 so as to cover the internal space. This allows the substrate holder 73 to house sensor components in a state where contamination is prevented.

[0127] Although the board holding portion 73 is formed in a frame shape, it is not limited to this and may be formed in a recessed shape as long as it allows the rotation shaft 13 to be inserted and forms a space in which the sensor components can be arranged. The board holding portion 73 is fixed to the wall portion 212 by inserting and fitting (e.g., screwing) the fastening member 85, which passes through the fastening hole 702, into the fastening hole 215 of the wall portion 212.

[0128] The encoder disk 74 is fixed to one end 131 of the rotating shaft 13 via a central mounting portion (encoder hub) 742, and is positioned within the opening 732 of the substrate holding portion 73 (inside the sensor placement portion 701).

[0129] The encoder disk 74 detects the number of rotations of the rotating shaft 13 and rotates integrally with the magnet 32 ​​and the mirror section 12. The rotational position of the encoder disk 74 around the axis is the same as the rotational position of the rotating shaft 13.

[0130] The optical sensor 76 is disposed opposite the encoder disk 74. 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. This allows the rotational positions of the magnet 32 ​​and the mirror section 12 to be detected accurately with high resolution.

[0131] The optical sensor 76 is mounted on the back surface of the sensor substrate 72. When the sensor substrate 72 is attached to the substrate holding part 73, the optical sensor 76 is arranged so as to face the encoder disk 74 in the axial direction within the sensor arrangement part 701. The optical sensor 76 is arranged within the optical sensor arrangement part 701 so as to be able to detect the number of rotations and rotation position of the encoder disk 74.

[0132] The sensor substrate 72 is arranged so as to close the opening 732 of the substrate holder 73 from the one end 131 side, and forms a closed sensor arrangement portion 701.

[0133] The sensor board 72 has an opening 724 in the center, and an attachment shaft portion (encoder hub) 742 for attaching the encoder disk 74 and the rotating shaft 13 are inserted into this opening 724, and these can be supported by the sensor board 72. The fastening member 84 is fastened to the fastening hole 703 of the board holding portion 73 via the fastening hole 723, thereby fixing the sensor board 72 to the board holding portion 73. As a result, the sensor board 72 is fixed to the board holding portion 73 which is fixed to the wall portion 212, and therefore fixed to the wall portion 212 via the board holding portion 73.

[0134] The wall 212, the substrate holder 73 and the sensor substrate 72 are provided with positioning holes 205, 705, 725 and position adjustment holes 207, 707, 727 used to position and fix the angle sensor unit 70 to a suitable position on the wall 212.

[0135] The positioning holes 205, 705, 725 are arranged with the same diameter (including approximately the same diameter) on the same axis parallel to the rotation shaft 13. The position adjustment holes 207, 707, 727 are arranged with the same shape on the same axis parallel to the rotation shaft 13, and are shaped so that a gap is created when a rod-shaped adjustment member (not shown) is inserted through them.

[0136] With these configurations, before fastening the wall portion 212, the substrate holding portion 73, and the sensor substrate 72 with the fastening member 84, adjustment members (not shown) are inserted into the position adjustment holes 207, 707, and 727. In this state, the wall portion 212, the substrate holding portion 73, and the sensor substrate 72 can be moved and adjusted to suitable positions, while inserting rod-shaped positioning members so as to pass through the positioning holes 205, 705, and 725, respectively. As a result, the substrate holding portion 73 and the sensor substrate 72 are positioned at suitable positions relative to the wall portion 212, centered on the rotation axis 13. In this state, the substrate holding portion 73 and the sensor substrate 72 can be fixed to the wall portion 212 in suitable positions.

[0137] The sensor board 72 is fixed to the board holder 73 via a fastening member 84 that passes through the fastening hole 703 so that the mounted optical sensor 76 faces the encoder disk 74 within the opening 732 .

[0138] Simply by attaching the sensor substrate 72 to the substrate holder 73, it is possible to prevent foreign matter such as dust from entering the sensing portion of the angle sensor unit 70, which includes the optical sensor 76 and the encoder disk 74.

[0139] Next, the operation of the rotary reciprocating actuator 1 will be described with reference to Figures 3 and 15. Figure 15 is a diagram illustrating the operation of the magnetic circuit of the rotary reciprocating actuator 1.

[0140] The magnetic poles 410a, 410b of the two rod-shaped portions 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 portion 48, as shown in FIG.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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. 15, and magnetic pole 410a becomes an S pole and magnetic pole 410b becomes an N pole. Magnetic pole 410a magnetized as an S pole attracts N pole 32b of magnet 32, and magnetic pole 410b magnetized as an N pole attracts S 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. 15. The rotary reciprocating actuator 1 rotates and reciprocates the mirror section 12 by repeating the above operations.

[0145] 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. 21). 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.

[0146] 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].

[0147]

number

[0148] Since the movable body constitutes the mass part in the vibration model of the spring-mass system, the resonance frequency F 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.

[0149] 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).

[0150]

number

[0151]

number

[0152] 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).

[0153] 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.

[0154] <Variation 1> Fig. 16 is an external perspective view of the rotary reciprocating drive actuator variation 1, and Fig. 17 is a longitudinal cross-sectional view passing through the axis of the rotary reciprocating drive actuator variation 1. Fig. 18 is an exploded perspective view of the rotary reciprocating drive actuator variation 1, and Fig. 19 is a perspective view of a wall portion on one end side of the rotary reciprocating drive actuator variation 1. Fig. 20 is an exploded perspective view of the front side of a sensor portion disposed on the wall portion on the same end side.

[0155] The rotary reciprocating drive actuator 1A of Modification 1 differs from the rotary reciprocating drive actuator 1 having a substantially similar configuration only in that the substrate holding section of the angle sensor section 70A attached to the wall section 212A at one end of the base section 21A is provided on the wall section 212A, and 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.

[0156] In the rotary reciprocating drive actuator 1A shown in Figures 16 to 20, a main body unit 2A is formed by attaching a movable body 10A to a base portion 21A. The main body unit 2A is formed by attaching a movable body 10 to the base portion 21A. The base portion 21A and the drive unit 4 form a fixed body 20A that supports the movable body 10 so that it can be rotated back and forth. The rotary reciprocating drive actuator 1A has an angle sensor unit 70A on a wall portion 212A that is one end of the main body unit 2A, and has a drive unit 4 on a wall portion 211A that is located on the other end side of the main body unit 2A. The angle sensor unit 70A also has an encoder disk 74, an optical sensor 76, and a sensor substrate 72.

[0157] Unlike the rotary reciprocating actuator 1, the rotary reciprocating actuator 1A does not have a substrate holding section, and the function of the substrate holding section is provided integrally in the wall section 212A. The wall section 212A, together with the wall section 211A, stands vertically from both ends of a flat bottom section 213A configured similarly to the bottom section 213, and faces each other at a distance. A concave sensor placement section 230 that opens toward the other end section 131 is provided in the wall section 212A of the base section 21A.

[0158] Specifically, a wall 212A on the other end side of the base 21A, which has the same configuration as the base 21, has a frame-shaped peripheral wall 240 that has the same function as the substrate holding part 73. On the outer surface 21a of the wall 212A, a recessed sensor arrangement part 230 is provided in the central part surrounded by the frame-shaped peripheral wall 240. One end 131 of the rotation shaft 13 that passes through the wall 212A protrudes from the sensor arrangement part 230.

[0159] Similar to the embodiment, this sensor arrangement section 230 has an encoder disk 74 fixed to the rotation shaft 13 inside via a mounting shaft section 742. Furthermore, within the sensor arrangement section 230, the sensor board 72 is attached to the wall section 212A so that the optical sensor 76 mounted on the sensor board 72 faces the encoder disk 74.

[0160] The sensor substrate 72 is attached to the outer surface 21a of the wall 212A via the fastening holes 723, 215 by the fastening member 84 so as to cover the sensor placement portion 230. The configuration of the rotary reciprocating drive actuator 1A has the same effects as the embodiment, and since there is no need to use a separate member as a substrate holder, the number of parts can be reduced and the manufacturing time can be shortened. When attaching the sensor substrate 72 to the wall 212A, the positioning holes 205, 725 and the position adjustment holes 207, 727 provided in the wall 212 and the sensor substrate 72 can be used to position the sensor substrate 72 on the wall 212A at a suitable position around the rotation axis 13.

[0161] <Scanner System 100> FIG. 21 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.

[0162] The scanner system 100 is either a rotary reciprocating actuator 1 or 1A, and in addition to the rotary reciprocating actuator 1 or 1A, has a laser emitting unit 101, a laser control unit 102, a drive signal supply unit 103, and a position control signal calculation unit 104.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] <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.

[0167] The rotating shaft 13 is rotatably supported by a pair of wall portions 211, 212 of the base portion 21. The core assembly 40 is attached to the other wall portion 211 of the pair of wall portions 211, 212, and an angle sensor portion 70 that detects the rotation angle of the rotating shaft 13 is disposed on one wall portion 212 of the pair of wall portions 211, 212. A sensor (optical sensor) 76 is mounted in the angle sensor portion 70, and a sensor board 72 is attached to one wall portion 212 from one end portion 131 side with the sensor facing the one wall portion.

[0168] In this way, the angle sensor components (encoder disk, etc.) are positioned near bearing 23 at a position away from core assembly 40, so there is no need to worry about the effects of electromagnetic noise, heat generation, or mechanical influences from the core assembly during operation, and angle detection can be performed favorably without being affected by axial wobble of rotating shaft 13. Therefore, the rotation of the shaft connected to the movable object can be accurately detected, and the movable object can be driven more favorably with high amplitude.

[0169] The sensor substrate 72 covers the detection portion (encoder disk) of the sensor component outside the sensor arrangement portion 701, 230. This makes it possible for the sensor substrate 72 to prevent contamination inside the sensor arrangement portion 701, 230. In this way, foreign matter is prevented from entering the sensor arrangement portion 701, 230, allowing accurate rotation angle detection to be performed and the movable object to be driven appropriately.

[0170] The angle sensor unit 70 is configured by arranging an encoder disk 74, which is the part to be detected, at one end 131 of the rotating shaft 13, and facing an optical sensor 76 implemented on a sensor substrate 76 in the axial direction of the rotating shaft 13. This configuration results in a layout that minimizes the dimensions of the configuration in which the angle sensor unit 70 is disposed, making it possible to reduce the size of the rotary reciprocating drive actuator 1 itself and to stably hold the optical sensor 76.

[0171] Furthermore, when performing maintenance on the angle sensor unit 70, simply removing the fastening member 84 exposes the sensor component, which is an expensive component, to the outside in the event of a malfunction, allowing it to be easily recovered or replaced.

[0172] Furthermore, when the sensor section is an optical sensor, it is possible to prevent light interference with the sensor placement section (which may be a housing section that houses the sensor) 701, 230 without using a separate light-blocking member.

[0173] 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 specified from that reference. Also, when fixing the rotary reciprocating drive actuator to the product housing with the axis vertical, it is possible to assemble the rotary reciprocating drive actuator and attach it to the housing by positioning and fixing it in 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.

[0174] Furthermore, a gap (clearance) narrower than the air gap between the magnet 32 ​​and the core assembly 40 may be provided between the bushing 39 and the outer periphery of the 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, they will receive the shock reliably, preventing the shock from reaching the sensor portion and damping unnecessary vibrations of the movable body, thereby achieving low noise.

[0175] 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.

[0176] Furthermore, in the ring-shaped magnet 32 ​​of the rotary reciprocating drive actuators 1, 1A 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. 22, 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. 22 to 26.

[0177] Figures 22 to 26 show modified examples 1 to 4 of the magnet in the rotary reciprocating drive actuators 1 and 1A. Note that Figures A and B in Figures 23 to 25 show a front view and a right side view, respectively, of the magnet as a modified example, and Figure 26 is a view showing the core assembly of a rotary reciprocating drive actuator having modified example 4, and corresponds to an end view of the rotary reciprocating drive actuator having magnet 32 ​​taken along line AA in Figure 2.

[0178] Magnets 320, 320A, and 320B shown in FIGS. 23 to 25 are each ring-shaped, and each have an opening 321 in the center through which the rotary shaft 13 is inserted.

[0179] 23 has protruding magnetic pole switching portions 32e and 32f integrally formed on the diameter portion of one end face 322. Magnetic pole switching portions 32e and 32f are protruding bodies (protrusions) formed on the same straight line on end face 322, sandwiching opening 321, and their tip surfaces may be rounded or flat.

[0180] The magnetic pole switching portions 32e and 32f of the magnet 320 allow the position where the magnetic poles of the magnet 320 are switched to be determined by the shape of the magnet 320.

[0181] Furthermore, compared to magnet 320, magnet 320A shown in FIG. 24 has magnetic pole switching portions 32g and 32h that have a V-shaped cross section instead of a U-shaped cross section on end surface 322 of the ring-shaped main body.

[0182] The magnetic pole switching portions 32g and 32h of the magnet 320A allow the position where the magnetic poles of the magnet 320A are switched to be determined by the shape of the magnet 320A.

[0183] Here, it is desirable that the assembly precision of the magnetic pole directions of magnets 320 and 320A as well as magnet 32 ​​be well-balanced and aligned with the angle reference of mirror unit 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.

[0184] 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.

[0185] 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.

[0186] That is, using the concave and convex portions (magnetic pole switching portions 32c, 32d, 32e, 32f, 32g, 32h) as references, it is possible to adjust the positional relationship of the components fixed to the rotary shaft 13 during assembly or maintenance of the rotary reciprocating drive actuator 1. With the rotary reciprocating drive actuator 1, the angular accuracy of the mirror portion 12, the angle reference of the angle sensor portion 70, and the magnetic pole reference of the magnet 32 ​​can be easily aligned, making it easy to achieve high-precision assembly.

[0187] 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 position 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 position holding unit 48.

[0188] 25 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.

[0189] When core assembly 40B having magnet 320B is installed in rotary reciprocating drive actuator 1, it 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. 26. 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 (or rotation axis 13) and is perpendicular to flat surface 328.

[0190] In magnet 320B, for example, if flat surface 328 is positioned facing rotation angle position holding portion 48 or the core (magnetic poles 410a, 410b), 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.

[0191] In contrast to this, in the present embodiment, flat surface 328 of magnet 320B is configured to be located on the opposite side of rotational axis 13 from rotational angle position 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 portion 414 while avoiding an effect on rotational angle position holder 48, that is, while avoiding an imbalance in torque generation. Note that flat surface 328 can also be used as a reference for assembling other components or assembling a rotary reciprocating actuator.

[0192] 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.

[0193] 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.

[0194] Furthermore, for example, in the embodiment, the rotary reciprocating drive actuator 1 is resonantly driven, but the present invention can also be applied to non-resonant driving.

[0195] 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.

[0196] Furthermore, although the rotation angle position retaining section 48 provided on the fixed body 20 is configured to be attached to the second core 42, this is not limiting and the rotation angle position retaining section 48 may be configured to be attached to another component of the fixed body 20. Also, for example, the rotation angle position retaining section 48 may be provided so as to protrude from the surface of the cover main body 52 or the back surface of the top cover main body 62 so that it is positioned in the same position as when it is attached to the second core 42. In these cases, the rotation angle position retaining section 48 may be accommodated within the drive unit 4.

[0197] 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]

[0198] The present invention is suitable for use in, for example, LiDAR devices and scanner systems. [Explanation of symbols]

[0199] 1. 1A rotary reciprocating drive actuator 2 Main unit 4 Drive Unit 10, 10A movable body 12 Mirror section 13 Rotation axis 14 Stopper 15, 15A stopper part 20 Fixed body 21, 21A base part 21a Exterior 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 Preload spring 37 Annular receiving part 39 Bush 40 Core assembly 41 First Core 42 Second core (bridge part) 43 Third Core 44, 45 coils 46, 47 Bobbin 48 Rotation angle position holding unit 49 Coil body 50 bottom cover 52 Cover body 53, 321, 732 openings 54, 55, 66 Through holes 56, 205, 705, 725 Positioning holes 57, 207, 707, 727 position adjustment hole 58 Positioning protrusion 60 Top cover 62 Top cover body 64 Peripheral wall section 67 Bobbin engagement hole 70, 70A angle sensor part 72 Sensor board 73 Board holding part 74 Encoder disk (detected part) 76 Light Sensor (Sensor) 81, 84, 85, 86 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, 212a Insertion holes 131 One end 132 Other end 133 Fitting groove 203, 215, 402, 702, 703, 723 Fastening hole 211, 211A, 212, 212A Wall section 211a, 211Aa, 212a Insertion holes 213, 213A bottom 218 recess 222, 232 Bearing body 224, 234 flange 230, 701 Sensor placement section 322 End face 326 Outer surface 328 Flat surface 400 Core Body 411, 411a, 411b Rod-shaped part 412 Connecting edge 413, 413a, 413b side part 414 Interpolator 492 Bobbin section 494 Terminal support part 496 terminals 522 Mounting part 541 Counterbore 621 Concave part 742 Mounting shaft 4964 Other side 4962 Side

Claims

1. a movable body having a shaft portion to which a movable object is connected at one end side and a magnet fixed to the shaft portion at the other end side, the movable body being supported so as to be rotatable back and forth around the shaft; a base portion that rotatably supports the shaft portion via a bearing at the one end side and has a pair of walls that are arranged to sandwich the movable object; a core assembly attached to a first wall portion of the pair of walls, the 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; a coil body wound around the core body, which generates magnetic flux that interacts with the magnet when current is applied, causing the movable body to rotate back and forth; and a magnet position holder that generates a magnetic attraction force between itself and the magnet and determines a reference position for the reciprocating rotation; a sensor board attached to a second wall portion of the pair of wall portions and having a sensor mounted thereon that detects a rotation angle of the shaft portion; and a recessed sensor placement portion through which the one end portion is inserted and which opens to the outside is provided on the outer surface of the second wall portion; the sensor substrate is disposed in the sensor arrangement section so as to close the sensor arrangement section with the sensor facing the second wall portion. Rotary reciprocating drive actuator.

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

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

3. The sensor is an optical sensor.

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

4. a substrate holding portion that surrounds the sensor and that holds the sensor substrate attached to the one end of the second wall portion; having 2. The rotary reciprocating drive actuator according to claim 1.

5. the movable object is a mirror that reflects the scanning light; 2. The rotary reciprocating drive actuator according to claim 1.

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