Rotary reciprocating actuator

Abstract

This invention provides a rotary reciprocating actuator that is easy to assemble and achieves high amplitude through high torque rotational drive. [Solution] The mounting surface 50 has a rotatable shaft portion 15 that protrudes from a predetermined position and to which a movable object is connected, a magnet fixed to the outer circumference of the shaft portion, a core 400 having magnetic poles at its tip that face the outer circumference of the magnet, and a coil that generates a magnetic flux in the core by energizing to interact with the magnet and cause the shaft portion to reciprocate, and a plate-shaped cover portion 60 that passes through one end of the shaft portion and covers one end of the core assembly. The predetermined position is an eccentric position on the mounting surface in the direction from the center toward the corner, and the core assembly is fixed to the mounting surface so that a pair of rod-shaped bodies are aligned along a diagonal line passing through the corner, and the cover portion has a boss portion 68 that protrudes toward the core assembly and engages inside the core assembly to restrict rotation in the circumferential direction about the shaft portion.

Description

[Technical Field]

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

[0002] Conventionally, rotary reciprocating actuators have been used as actuators in optical scanning devices such as multifunction printers and laser beam printers. Specifically, rotary reciprocating actuators achieve optical scanning of an object by changing the reflection angle of the laser beam by reciprocating the rotation of the scanner's mirror.

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

[0004] Patent Document 1 discloses a beam scanner in which four permanent magnets are provided on a rotating shaft to which a mirror is attached, so as to magnetize in the radial direction of the rotating shaft, and the magnetic poles of a salient-pole yoke around which a coil is wound are arranged so as to sandwich the rotating shaft. The body of the salient-pole yoke is positioned to extend downward along the rotating shaft. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 4727509 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, as in the beam scanner described in Patent Document 1, the galvanometer motor has a predetermined height from its mounting surface to its upper edge (one side) in order to secure the rotational area of ​​the mirror attached to the rotating shaft and to secure the installation area for the salient pole yoke, coil and magnet for rotating the rotating shaft.

[0007] However, in recent years, there has been a demand for lower profile rotary reciprocating drive actuators, such as galvanometer motors, used in beam scanners and the like, without reducing their output. In addition, during assembly, the rotation angle of the mirror, which is the movable object, is important. Therefore, in order to ensure high precision and high torque output of the mirror, it is desirable to fix it at a position where the dimensions can be defined based on the rotation axis.

[0008] This invention has been made in view of the above, and aims to provide a rotary reciprocating actuator that is easy to assemble and can achieve high amplitude through high torque rotational drive. [Means for solving the problem]

[0009] The rotary reciprocating drive actuator of the present invention is A rotatable shaft portion protrudes from a predetermined position on the mounting surface and to which a movable object is connected, A magnet fixed to the outer circumference of the aforementioned shaft portion, A core assembly comprising a core having a pair of rod-shaped magnetic bodies having magnetic poles at their tips facing each other on the outer circumference of the magnet, and a frame-shaped magnetic body connected to the base ends of the pair of rod-shaped magnetic bodies to form a magnetic path surrounding the magnet and the magnetic poles, and a coil that generates a magnetic flux in the core by energizing the core to cause the shaft to reciprocate and rotate, A plate-shaped cover portion is inserted through one end of the shaft portion and covers the one end of the core assembly, It has, The predetermined position is an eccentric position on the mounting surface, in the direction from the center toward the corner. The core assembly is fixed to the mounting surface such that the pair of rod-shaped bodies are aligned along the diagonal lines passing through the corners. The lid portion is configured to have a boss portion that protrudes toward the core assembly side and engages inside the core assembly to restrict circumferential rotation about the shaft portion.

Advantages of the Invention

[0010] According to the present invention, assembly is easy, and high amplitude can be achieved by rotational driving at high torque.

Brief Description of the Drawings

[0011] [Figure 1] FIG. 1 is an external perspective view of a rotary reciprocating drive actuator according to an embodiment of the present invention. [Figure 2] FIG. 2 is a left side view of a rotary reciprocating drive actuator according to an embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 2. [Figure 4] FIG. 4 is an exploded view of a rotary reciprocating drive actuator according to an embodiment of the present invention. [Figure 5] FIG. 5 is an external perspective view of a drive unit of a rotary reciprocating drive actuator according to an embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view of the same drive unit taken along the line A-A in FIG. 2. [Figure 7] FIG. 7 is an exploded perspective view showing the internal configuration of the same drive unit. [Figure 8] FIG. 八 is an exploded perspective view of the drive unit in FIG. 7 as viewed from the bottom cover side. [Figure 9] FIG. 9 is a view showing the internal configuration of the drive unit. [Figure 10] FIG. 10 is an exploded view of the core body. [Figure 11] FIG. 11 is a view of the core body in FIG. 10 as viewed from the bottom cover side. [Figure 12] FIG. 12 is a view showing the overall configuration of the core body. [Figure 13] FIG. 13 is an exploded perspective view of the drive unit. [Figure 14]Figure 14 is an enlarged view of the preload section of a rotary reciprocating actuator. [Figure 15] Figure 15 shows a modified example of the preload section of a rotary reciprocating actuator. [Figure 16] Figure 16 is a diagram illustrating the magnetic circuit configuration of a rotary reciprocating actuator. [Figure 17] Figure 17 illustrates the method of applying preload to a rotary reciprocating actuator. [Figure 18] Figure 18 is a block diagram showing the main components of an example scanner system having a rotary reciprocating actuator. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0013] In this embodiment, the position of each part constituting the rotary reciprocating actuator when the rotary reciprocating actuator is not driven and is in a non-operating state will be described as the reference position, which is the reference position for the operation of each part. Furthermore, when describing the structure of the rotary reciprocating actuator in this embodiment, a Cartesian coordinate system (X, Y, Z) will be used. The figures described later will also be shown using the same Cartesian coordinate system (X, Y, Z). In addition, in this embodiment, in order to describe the configuration and operation of the rotary reciprocating actuator, the X direction will be expressed as the right direction, the -X direction as the left direction, and the Z direction as the upward direction. These expressions indicating directions are relative, not absolute, and are appropriate when each part of the rotary reciprocating actuator is in the posture shown in the figure, but should be changed and interpreted according to the change in posture when the posture changes.

[0014] <Overall configuration of a rotary reciprocating actuator> Figure 1 is an external perspective view of a rotary reciprocating actuator according to an embodiment of the present invention, and Figure 2 is a left side view of the rotary reciprocating actuator according to an embodiment of the present invention. Furthermore, Figure 3 is a cross-sectional view taken along line AA in Figure 2, and Figure 4 is an exploded view of the rotary reciprocating actuator according to an embodiment of the present invention.

[0015] The rotary reciprocating actuator 1 reciprocates and rotates a movable body 10, to which a movable object is connected, around a first shaft portion 15 and a second shaft portion 14. The rotary reciprocating actuator 1 includes, for example, a mirror portion 11 as the movable object on the movable body 10. The rotary reciprocating actuator 1 is used in LiDAR (Light Detection and Ranging: Laser Imaging Detection and Ranging), etc. In LiDAR, the rotary reciprocating actuator 1 is used as an optical scanner that irradiates the scanning target with laser light or the like using the mirror portion 11 and acquires the reflected light to obtain information about the scanning target. The rotary reciprocating actuator 1 is applicable to scanning devices such as multifunction printers and laser beam printers. In particular, the rotary reciprocating actuator 1 can function suitably even when subjected to external forces, and is preferably applied to devices that may be subjected to impacts while driving, such as vehicle-mounted scanner devices.

[0016] The rotary reciprocating actuator 1 comprises, broadly speaking, a movable body 10, a base portion 21 that rotatably supports the movable body 10, and a drive unit 4 that reciprocates and rotates the movable body 10 relative to the base portion 21.

[0017] The movable body 10 has a mirror section 11, a second shaft section (spindle) 14, and holders (mirror holders) 12 and 13, which are the movable objects, and is connected to the first shaft section (spindle) 15 of the drive unit 4. The first shaft section 15, together with the magnet 32, constitutes the movable part of the drive unit 4. The first shaft section 15 is also an output shaft that outputs the driving force of the drive unit 4 to the movable body 10. The magnet 32 ​​is fixed to one end 152 of the first shaft section 15, and the mirror section 11 is connected to the other end.

[0018] The movable body 10 is supported by the base portion 21 so as to be able to reciprocate and rotate via the first shaft portion 15 and the second shaft portion 14 of the drive unit 4, which is fixed to the base portion 21. The base portion 21, together with the portion fixed to the base portion 21 in the drive unit 4 including the coil 44, constitutes a fixed body 20 that supports the movable body 10 so as to be able to reciprocate and rotate.

[0019] In the rotary reciprocating drive actuator 1, the magnet 32 ​​(see Figure 3) is located inside the core assembly 40, and the first shaft portion 15 passes through the core assembly 40. The core assembly 40 includes a coil 44, a core body 400 (see Figures 7 to 13), and a magnet reference position holding portion (hereinafter also referred to as the "reference position holding portion") 48. The drive unit 4 has the core assembly 40, the magnet 32, the first shaft portion 15, a bottom cover 50, and a top cover 60.

[0020] In the drive unit 4, the first shaft 15 is driven to reciprocate rotation by the cooperation of the energized coil 44, the reference position holding part 48, the magnet 32, and the core body 400 (see Figure 7). This rotation of the first shaft 15 causes the movable object (mirror part 11) connected to the first shaft 15 to reciprocate rotation around the first shaft 15 and the second shaft 14. Further details regarding the configuration of the drive unit 4 and the core assembly 40 will be described later.

[0021] The mirror section 11 is rotatably mounted to the base section 21 together with the first shaft section 15, the second shaft section 14, and the holders 12 and 13 of the drive unit 4. The wall section 211 corresponds to the mounting target section, and the mounting surface section corresponds to the bottom cover 50.

[0022] The mirror portion 11 is a movable object in the rotary reciprocating drive actuator 1. The mirror portion 11 has a mirror surface. The mirror surface functions as a reflective surface that reflects scanning light. The shape of the reflective surface can be any shape, such as a rectangular plate, a disc, or a V-shape. In this embodiment, the mirror portion 11 is, for example, composed of a long plate-like body having a rectangular reflective surface.

[0023] The mirror section 11 has holders 12 and 13 attached to both ends in the longitudinal direction, for example, in the axial direction, via fastening members 17 (see Figure 4), and is connected to the first shaft section 15 and the second shaft section 14 via the holders 12 and 13. The first shaft section 15 is connected to holder 12, and the second shaft section 14 is connected to holder 13. The first shaft section 15 and the second shaft section 14 are located on the same axis and are positioned on the axis of the mirror section 11. The holders 12 and 13 and the first shaft section 15 and the second shaft section 14 are firmly connected via fastening members such as grub screws as shown in the figure.

[0024] The first shaft portion 15 and the second shaft portion 14 are inserted into and supported by a pair of walls 211 and 212 (first wall portion 211 and second wall portion 212) of the base portion 21, respectively.

[0025] As shown in Figures 1, 3, and 4, the base portion 21 rotatably supports the mirror portion 11, which is the movable object, by sandwiching it from both sides in the axial direction via the shaft portions (first shaft portion 15 and second shaft portion 14).

[0026] <Base section 21> The base portion 21 has a flat upper surface facing the mirror portion 11 and a bottom portion 213 that extends in the axial direction. A pair of wall portions 211 and 212 are provided at both ends of the bottom portion 213 so as to rise parallel to each other and facing each other. The base portion 21 has a roughly U-shaped cross-section formed by the bottom portion 213 and the pair of wall portions 211 and 212. The pair of wall sections 211 and 212 are each roughly rectangular (including rectangular) plate-like bodies, and the entire base section 21 has a rectangular parallelepiped shape.

[0027] A pair of wall portions 211 and 212 have through holes 211a and 212a, and the first shaft portion 15 and the second shaft portion 14 are inserted through the through holes 211a and 212a, respectively, with the shafts positioned on the same straight line. In particular, a bearing (wall bearing) 22 is provided in the through hole 212a of wall portion 212, and the second shaft portion 14 is supported by the wall portion 212 via the bearing 22.

[0028] The insertion holes 211a and 212a are formed in the wall portions 211 and 212 at eccentric positions when viewed from the axial direction, that is, near one corner 210 of the upper part of the wall portions 211 and 212. As a result, the mirror portion 11 is positioned on the base portion 21 between the wall portions 211 and 212, near one corner portion 210, via the second shaft portion 14 and the first shaft portion 15.

[0029] Specifically, the insertion hole 211a is located in the wall portion 211 at a position closer to the corner portion 210 formed by the orthogonal edges 2111 and 2112 in the wall portion 211, rather than at the center when viewed from the axial direction. With this configuration, when the mirror portion 11 rotates back and forth, the incidence of scanning light to the mirror portion 11 and the emission of scanning light from the mirror portion 11 are not obstructed (shielded) by the base portion 21 itself, and as a result, suitable scanning can be achieved.

[0030] It is preferable that the through holes 211a and 212a are formed at diagonal positions in the respective wall portions 211 and 212. Here, the diagonal in the wall portions 211 and 212 is a line that extends inclined so as to coincide with the diagonal DL (see Figure 9) in the bottom cover 50. Incidentally, the diagonal DL of the bottom cover 50 is a line that extends connecting a pair of diagonals in the bottom cover 50, and is an example of a diagonal line that extends in the direction from the center toward the corner portion 510 in the bottom cover 50. It is particularly preferable that the through holes 211a and 212a are formed at positions near the diagonal corner portion 210 in the respective wall portions 211 and 212. This makes it possible to position the first shaft portion 15 and the second shaft portion 14 at diagonal positions in the wall portions 211 and 212, that is, near the corner portion 210 that is shifted upward from the center in the Z direction in the wall portions 211 and 212.

[0031] As a result, the rotation center and rotation region of the mirror portion (movable object) 11, which are set by the first shaft portion 15 and the second shaft portion 14, are located at a position offset from the center of the wall portions 211 and 212, for example, at a position offset in the Z direction (upward). With this configuration, the length L between opposing sides in the offset direction (Z direction) can be shortened compared to when the rotation center of the mirror portion 11 is located at the center of the wall portions 211 and 212, when viewed in the axial direction. In other words, the length L in the Z direction of both the wall portions 211 and 212 and the length L in the Z direction of the bottom cover 50 can be shortened, thus enabling a lower profile.

[0032] The bearing 22 has a flange 224 on the outer circumference of one of the opening ends of its annular body, which opens in the center, and is fitted into the through hole 212a from the inside. The through hole 212a is provided with a counterbore portion 212b (see Figures 3 and 4) which is a step at the axially inner opening edge.

[0033] The bearing 22 is fitted into the wall portion 212 from the axial inner side, and the flange 224 restricts the bearing 22 from moving axially outward. The second shaft portion 14, which protrudes from the holder 13, is inserted through the bearing 22, and an axial movement restricting portion 23, such as an E-ring, is fitted onto the second shaft portion 14 at a portion that protrudes to the outer surface of the wall portion 212. In this way, the bearing 22 engages with the wall portion 212 from the inside, restricting the axial movement of the first shaft portion and the mirror portion 11 toward the outside of the wall portion 212.

[0034] The axial movement restricting portion 23 is positioned on the outer surface side of the wall portion 212 and restricts the axial inward movement of the second shaft portion 14, preventing the second shaft portion 14 from coming out of the wall portion 212 in the axial inward direction.

[0035] The first shaft portion 15, which is connected to the holder 12, is inserted through the insertion hole 211a. The first shaft portion 15 is positioned to protrude into the base portion 21 from the drive unit 4, which is fixed to the outer surface of the wall portion 211.

[0036] <Drive Unit 4> Figure 5 is an external perspective view of the drive unit of a rotary reciprocating drive actuator according to an embodiment of the present invention, and Figure 6 is a cross-sectional view of the same drive unit shown by line AA in Figure 2. Figure 7 is an exploded perspective view showing the internal configuration of the drive unit, and Figure 8 is an exploded perspective view of the drive unit of Figure 7 viewed from the bottom cover side. Figure 9 is a diagram showing the internal configuration of the drive unit, and Figure 10 is an exploded view of the core body. Figure 11 is a view of the core body of Figure 10 viewed from below, and Figure 12 is a diagram showing the overall configuration of the core body. Figure 13 is an exploded perspective view of the drive unit.

[0037] The drive unit 4 shown in Figures 1 to 9 is attached to one of the two ends of the base portion 21 that are spaced apart in the axial direction (specifically, the wall portion 211), and drives the mirror portion 11, which is located inside the base portion 21, to reciprocate rotation.

[0038] The drive unit 4 is fixed to the outer surface of the wall portion 211 via fastening members 16. The fastening members 16 may be, for example, screws, bolts, or bolts and nuts. In this case, the two fastening members 16 are fastened so that the drive unit 4 and the wall portion 211 are stacked together, with the drive unit 4 in surface contact with the wall portion 211 at a position closer to the wall portion 211 than the axial length of the second shaft portion 14.

[0039] The drive unit 4 includes a core assembly 40, a bottom cover 50, and a top cover 60, along with the first shaft portion 15 and the magnet 32. The drive unit 4 houses the magnet 32 ​​with the first shaft portion 15 inserted through it in a fixed-side unit that is fixed to the wall portion 211. The side of the drive unit 4 where the magnet 32 ​​is housed is the side of the drive unit 4 that is fixed to the wall portion 211 (fixed side). This constitutes the movable-side unit of the drive unit 4.

[0040] The bottom cover 50 is formed in a plate shape (here, a rectangular plate shape), and for example, its surface area is smaller than that of the wall portion 211, and it is stacked within the outer surface of the wall portion 211. The drive unit 4 is fixed to the wall portion 211 via a fastening member 16 at a diagonal position Q on the bottom cover 50, when viewed from the surface side of the bottom cover 50, sandwiching the core assembly 40. The surface side of the bottom cover 50 is the left side of the rotary reciprocating drive actuator 1, or in other words, the negative side in the X direction. The drive unit 4 is fixed to the wall portion 211 at a diagonal position of the bottom cover 50 stacked on the wall portion 211. Therefore, the drive unit 4 can be firmly attached to the base portion 21 without rotating it around the axis of the first shaft portion 15.

[0041] The core assembly 40 is positioned on the bottom cover 50 so as to surround the first shaft portion 15 and the magnet 32 ​​in a direction perpendicular to the axial direction (or in the circumferential direction). The top cover 60 is attached to the core assembly 40 in a stacked manner in the axial direction.

[0042] The drive unit 4 is provided with the first shaft portion 15 protruding axially at a position near the corner portion 510 formed by the orthogonal sides 52 and 54. The position near the corner portion 510 is, when viewed from the surface side of the bottom cover 50, a position closer to the corner portion 510 than the center of the bottom cover 50.

[0043] The core assembly 40 is composed of a frame-shaped block having a predetermined thickness (axial length), including a trapezoidal portion (mountain-shaped portion) that surrounds the first shaft portion 15 in a direction perpendicular to the first shaft portion 15. Viewed in the axial direction, the outer shape of the top cover 60 is the same as that of the core assembly 40. The inclined edges of the core assembly 40 that constitute the magnetic path surrounding the magnet 32 ​​are arranged along the edges 52 of the bottom cover 50.

[0044] <Core assembly 40> As shown in Figures 1, 3 to 9, the core assembly 40, together with the first shaft portion 15, the magnet 32, the bottom cover 50, and the top cover 60, constitutes the drive unit 4. The core assembly 40, together with the magnet 32, constitutes a magnetic circuit that reciprocates and rotates the first shaft portion 15.

[0045] The core assembly 40 includes coils 44 (44a, 44b), bobbins 46a, 46b around which the coils 44 (44a, 44b) are wound, a core body 400, and a reference position holding part 48.

[0046] The core assembly 40 is formed in a rectangular frame-shaped block (more specifically, a rectangular parallelepiped shape) with magnetic poles of rod-shaped bodies 412a and 412b arranged inside. The core assembly 40 is formed so as to surround the magnetic poles, which are the tips of the rod-shaped bodies 412a and 412b, with its outer frame portion. The core assembly 40 is positioned, for example, within a rectangular area of ​​the wall surface of the wall portion 211 of the base portion 21 as viewed from the axial direction.

[0047] The core assembly 40 folds back from the base ends of the rod-shaped bodies 412a and 412b that sandwich the magnet 32, forming a single magnetic path that extends to surround the magnetic poles of the rod-shaped bodies 412a and 412b and the magnet 32.

[0048] <Coiled structure (coil and bobbin)> As shown in Figures 3, 6, 7, 9, and 13, the coils 44 (44a, 44b) are wound around the cylindrical bobbin bodies 462 of bobbins 46a and 46b. The coil body, consisting of coils 44a, 44b and bobbins 46a and 46b, is externally fitted onto the outer circumference of the central portions of the rod-shaped bodies 412a and 412b of the first core 41. In this way, coils 44a and 44b are positioned adjacent to the magnetic poles at the tips of the rod-shaped bodies 412a and 412b. By energizing, coils 44a and 44b energize the magnetic poles at the tips of the rod-shaped bodies 412a and 412b, generating polarity in the magnetic poles according to the direction of current flow.

[0049] The winding direction of coils 44a and 44b is set such that, when current is applied, a magnetic flux that interacts with the magnet 32 ​​is preferably generated from one of the multiple magnetic poles of the first core 41 toward the other magnetic pole.

[0050] The bobbin body 462 is provided with a terminal support portion 464 (see Figures 7, 9, and 13) that supports the terminal (terminal, terminal portion) 49. The terminal support portion 464 supports the L-shaped terminal 49 shown in Figures 7 and 13 such that both ends (the other end 491 and the one end 492) protrude in the direction of the coil axis and the direction of the second shaft portion 14 (the same applies to the first shaft portion 15). The bobbin body 462 brings the terminal 49 adjacent to or close to the coil 44a (or coil 44b) via the flange portion of the bobbin body 462 on which the terminal support portion 464 protrudes. The terminal 49 is positioned, for example, in close proximity to the coils 44a and 44b in the direction of the coil axis, that is, along the diagonal.

[0051] The terminal support portion 464 is formed to protrude axially from the first shaft portion 15, and this protruding portion is inserted into the through hole 66 of the top cover 60. As a result, one end 492 of the terminal 49 supported by the terminal support portion 464 is inserted through the top cover 60 and connected to the wiring of the substrate 72 via a through hole in the substrate 72 (see Figures 2 and 7). The other end 492 is connected to the coil wire that constitutes the coil 44.

[0052] <Core body 400> The core body 400 is part of the core assembly 40, is positioned to surround the magnet 32, and has a magnetic path through which magnetic flux flows. The core body 400, together with the coils 44 (44a, 44b) and the reference position holding part 48, constitutes a magnetic circuit.

[0053] The core body 400 is provided at the respective ends of the rod-shaped bodies 412a and 412b, and is formed by connecting multiple magnetic poles facing the magnet 32 ​​with a frame-shaped magnetic path arranged to surround the magnet 32. The core body 400 has a shape that allows magnetic flux to flow in one direction from one of the magnetic poles of the rod-shaped bodies 412a and 412b to the other (see Figure 16). In the core body 400, the magnetic flux generated when the coil 44 is energized passes between the magnetic poles at the ends of the multiple rod-shaped bodies 412a and 412b.

[0054] Specifically, as shown in Figures 10 and 11, the core body 400 integrally comprises a first core 41 having parallel rod-shaped bodies 412a and 412b, and a second core 42 connected to the first core 41 and including a magnetic path that connects the base ends of the multiple rod-shaped bodies 412a and 412b. The second core 42 is connected to the base ends of the multiple rod-shaped bodies 412a and 412b and forms a magnetic path that surrounds the magnetic poles and magnet 32 ​​in the radial direction (direction perpendicular to the axis). The second core 42 is a frame-shaped magnetic material. The rod-shaped bodies 412a and 412b are rod-shaped magnetic materials.

[0055] The first core 41 and the second core 42 are laminated cores formed by laminating electromagnetic steel sheets (laminated members), such as silicon steel sheets. By making the core body 400 a laminated structure, the first core 41 and the second core 42, which have complex shapes, can be formed at low cost.

[0056] <1st Core 41> In the first core (also called the "magnetic pole core") 41, a connecting edge portion 413 extending perpendicular to the extending direction of the rod-shaped bodies 412a and 412b is connected to the base ends of a plurality of rod-shaped bodies 412a and 412b, each having opposing magnetic poles at its tip. The rod-shaped bodies 412a and 412b are arranged on the bottom cover 50 along the diagonal DL and symmetrically with respect to the diagonal DL. Therefore, the rod-shaped bodies 412a and 412b are arranged at an inclination with respect to both the Z and Y directions.

[0057] The first core 41 is formed in a U-shape with rod-shaped bodies 412a, 412b and connecting edge portions 413, and the connecting edge portion 413 has a stepped portion 414 formed on its bottom surface (the surface on the X-direction side) that protrudes in a direction away from the magnetic pole.

[0058] The magnetic poles at the tips of the rod-shaped bodies 412a and 412b are curved surfaces formed in an arc shape on the side surfaces of each tip, facing each other. The curved surfaces of the magnetic poles are formed to correspond to the outer circumference shape of the magnet 32, that is, curved along the outer circumference of the magnet 32, and face the outer circumference of the magnet 32 ​​in a direction perpendicular to the axial direction. Furthermore, the magnetic poles at the tips of the rod-shaped bodies 412a and 412b are arranged such that the curved surfaces of the magnetic poles face each other in a direction perpendicular to the extending direction of the rod-shaped bodies 412a and 412b, for example. Since coils 44 are arranged on the rod-shaped bodies 412a and 412b, the coils 44 are arranged diagonally along the diagonal DL, ensuring a suitable length.

[0059] The rod-shaped bodies 412a and 412b have external dimensions that allow, for example, bobbins 46a and 46b to be extrapolated from the tip side. This allows the bobbins 46a and 46b to be extrapolated from the tip side of the rod-shaped bodies 412a and 412b. By extrapolating the bobbins 46a and 46b, the coils 44a and 44b can be positioned to surround the rod-shaped bodies 412a and 412b.

[0060] The connecting edge portion 413 is connected to the rod-shaped bodies 412a and 412b at their base ends and is arranged to extend in a direction perpendicular to the parallel direction of the rod-shaped bodies 412a and 412b.

[0061] The connecting edge portion 413, together with the stepped portion 414, is attached to the second core 42 so as to be stacked on the second core 42 with its bottom surface in close contact with the second core 42 in the axial direction.

[0062] The stepped portion 414 is formed with fixing holes 432 and positioning holes 433 for fixing the first core 41 and the second core 42, and for positioning the core body 400 on the bottom cover 50.

[0063] The fixing holes 432 are for fixing the first core 41 and the second core 42, and are formed in each of the first core 41 and the second core 42 so as to communicate with them in the axial direction.

[0064] A fastening member 19 is inserted through the fixing hole 432 of the stepped portion 414 and the fixing hole 432 of the second core 42, thereby fastening the first core 41 to the second core 42. The connecting edge portion 413 of the first core 41 and the lower surface of the stepped portion 414 make surface contact with the inner bottom surface of the second core 42, thereby integrally joining the first core 41 and the second core 42.

[0065] The positioning hole 433 communicates with the positioning hole 57 of the bottom cover 50, and by inserting the pin 37, the first core 41, the second core 42, and the bottom cover 50 can be positioned when assembling them.

[0066] <2nd Core 42> The second core 42, together with the first core 41, is a frame-like body that constitutes a magnetic path, positioned to surround the magnetic poles at the tips of the rod-shaped bodies 412a and 412b and the magnet 32 ​​from all sides. The second core 42 is formed in a trapezoidal frame shape, having inclined edges 422a, 422b and a top edge 422c, rather than being rectangular in the portion surrounding the first shaft portion 15.

[0067] When the second core 42 is viewed from the axial direction, and assuming that the top portion 422c extends in the left-right direction, the second core 42 has a shape in which inclined portions 422a and 422b are arranged side by side from both ends of the top portion 422c that extends to the left and right, with their ends inclined in a direction that separates them to the left and right. In the second core 42, the bottom portion 423, which is parallel to the top portion 422c that divides the frame portion, is provided so as to be spanned between the separated ends of the inclined portions 422a and 422b. Therefore, the second core 42 is a so-called isosceles trapezoidal frame that narrows in one direction.

[0068] As a result, the magnetic path formed by the frame of the second core 42 has a shape that narrows in one direction while surrounding the first shaft portion 15 in the radial direction of the axis. Therefore, even if the insertion point (opening 53) of the shaft portion (first shaft portion 15) in the rectangular bottom cover 50 is irregularly offset from the center of the surface and is located near the corner portion 510 formed by the edges 52 and 54, the second core 42 can be positioned so as to surround the first shaft portion 15 with an isosceles trapezoidal portion without hardly protruding from the area of ​​the rectangular bottom cover 50.

[0069] Specifically, the inclined edge portion 422a extends along the edge portion 52, and the inclined edge portion 422b extends further towards the center of the surface of the bottom cover 50 than the edge portion 54. As a result, the isosceles trapezoidal portion of the second core 42 can surround the first shaft portion 15 without extending beyond the edges 52 and 54 and out of the area of ​​the bottom cover 50.

[0070] As shown by dashed lines in Figure 12, the inclined edge portion 422a includes an inclined portion that overlaps with the edge portion 52, and an end portion of this inclined portion that is a linear portion parallel to the rod-shaped body 412b and connects to the base portion 423.

[0071] Similarly, the inclined edge portion 422b includes an inclined portion having a shape symmetrical to the inclined edge portion 422a in the second core 42, as shown by dashed lines in Figure 12, and an end portion of this inclined portion that is a linear portion parallel to the linear portion of the rod-shaped body 412b and the inclined edge portion 422a and connects to the base portion 423.

[0072] The base portion 423 has a shape in which the inner wall portion is cut out in a concave shape. The concave interior of the base portion 423 communicates with the space 401 of the second core. The connecting edge portion 413 and the stepped portion 414 of the first core 41 are placed on the inner bottom surface 424 inside the concave base portion 423, thereby joining the first core 41 to the second core 42.

[0073] The first core 41 is positioned inside the base portion 423, that is, within the second core 42, forming a core body 400 that surrounds the magnetic poles at the tips of the rod-shaped bodies 412a and 412b and the magnet 32. The core body 400 has a configuration that allows magnetic flux to pass through the magnetic poles when current is supplied to the coils 44a and 44b.

[0074] One of the inclined edges 422a and 422b (more specifically, the inclined edge 422b) is positioned to overlap the edge (upper edge) 2111 of the wall 211 to which the drive unit 4 is attached.

[0075] The inclined edges 422a and 422b and the top edge 422c are arranged to surround the first shaft portion 15, which is located near the corner of the bottom cover 50.

[0076] The axial end face of the second core 42 is flush with the axial end face of the first core 41. The second core 42 is fixed between the bottom cover 50 and the top cover 60 via fastening members 18 that are inserted (for example, fitted) into mounting holes (fastening holes) 431 provided on both the inclined edges 422a and 422b.

[0077] Furthermore, the positioning hole 433 of the second core 42 communicates with the positioning hole 433 of the first core 41 and the positioning hole 57 of the bottom cover 50. A pin 37 is inserted into the positioning hole 433 along with the positioning hole 57. In the core assembly 40, the pin 37 is inserted from the bottom cover 50 side to the central part in the axial direction (the positioning hole 433 portion of the first core 41) at the connection point between the base ends of the rod-shaped bodies 412a and 412b and the frame-shaped portion (see Figure 6). The pin 37 may also be inserted through the bottom cover 50 and fixed to the bottom cover 50. In the core assembly 40, the pin 37 is inserted at a position where the terminal 49 overlaps with one end 152 side of the first shaft portion (shaft portion) 15 when viewed in a plane perpendicular to the axial direction, and at a position spaced apart from the terminal 49.

[0078] In the core assembly 40, terminals 49 are positioned so as to overlap with pins 37 in the axial direction of the first shaft portion 15. Terminals 49 are connected to coils 44a and 44b, which are positioned in the center of rod-shaped bodies 412a and 412b, whose orientation is determined to be perpendicular to the axial direction.

[0079] In other words, terminal 49 is positioned in the core assembly 40 on the extension line of the pin 37 in the extending direction, and is connected to coils 44a and 44b at the base end side of coils 44a and 44b along the diagonal line DL (see Figure 9), which is perpendicular to the axial direction. In addition, terminal 49 is connected to the substrate 72 of the top cover 60 at a portion that extends in the axial direction (towards one end 152 of the first shaft portion 15).

[0080] With this configuration, the coil length of the terminal 49 in the core assembly 40 is not shortened by positioning it in a way that avoids overlapping with the pin 37 in the axial direction (parallel to the axial direction of the shaft, and in the direction in which the pin 37 extends). For example, since the core assembly 40 is positioned in a limited space relative to the mounting surface 50, if the terminal 49 is moved in a direction perpendicular to the axial direction to avoid overlapping, it will move towards the coils 44a and 44b. In this case, the coil lengths of coils 44a and 44b are shortened in the direction along the opposing wire DL, and the terminal 49 can be shifted in the same direction as a result of this configuration. In contrast, in the rotary reciprocating drive actuator 1, there is no need to shorten the coil lengths of coils 44a and 44b in the direction along the opposing wire DL so that the terminal 49 is positioned in a way that avoids overlapping with the pin 37 in the axial direction, and to shift the terminal in the same direction. In the rotary reciprocating drive actuator 1, the coil length can be secured, so high torque rotational drive can be performed and high amplitude can be achieved.

[0081] Furthermore, the mounting holes for the bottom cover 50 and the top cover 60 are arranged continuously in the axial direction within the mounting hole 431, and the fastening member 18 is inserted into the mounting hole 431 and the mounting holes for the bottom cover 50 and the top cover 60.

[0082] A reference position holding part 48 is attached to the second core 42 at the center of its extension direction and at a location facing the magnet 32.

[0083] In the assembled state of the drive unit 4, the first shaft portion 15 is inserted into the space surrounded by magnetic poles, and the magnet 32 ​​is positioned together with the first shaft portion 15. The magnetic poles of this magnet 32 ​​face each other at precise positions via an air gap G.

[0084] <Reference position holding part 48> The reference position holding part 48 uses, for example, a magnet (permanent magnet) with its magnetic poles pointed towards the magnet 32 ​​to generate a magnetic attractive force between itself and the magnet 32, thereby attracting the magnet 32. In other words, the reference position holding part 48, together with the rod-shaped bodies 412a and 412b, forms a magnetic spring between itself and the magnet 32. This magnetic spring maintains the rotational angle position of the magnet 32, i.e., the rotational angle position of the first shaft part 15, in the neutral position when the coils 44a and 44b are not energized (non-energized).

[0085] The neutral position is the reference position for the reciprocating rotation of the magnet 32, that is, the center position of the reciprocating rotation (oscillation), and is the position where the rotation angle is the same when rotating left and right around the axis during reciprocating rotation. The neutral position is also called the default position. When the magnet 32 ​​is held in the neutral position, the magnetic pole switching portion (the boundary portion between the south pole 32a and the north pole 32b) 32c of the magnet 32 ​​faces the magnetic poles of the rod-shaped bodies 412a and 412b.

[0086] Furthermore, the mounting position of the mirror section 11 can be adjusted based on the state in which the magnet 32 ​​is in the neutral position. The reference position holding section 48 may be made of a magnetic material that generates a magnetic attraction force between itself and the magnet 32.

[0087] The reference position holding section 48, mainly shown in Figures 3, 6, 7, 9, 13, 16, and 17, is incorporated into the core assembly 40 so as to face the magnet 32 ​​via an air gap G when the rotary reciprocating drive actuator 1 is assembled. The reference position holding section 48 is mounted, for example, in a recess 422d formed in the top portion 422c of the second core 42, with its magnetic poles facing the magnet 32.

[0088] <Magnet 32> The magnet 32 ​​is a ring-shaped magnet in which south poles 32a and north poles 32b (the polarity may be reversed) are arranged alternately in the circumferential direction. The magnet 32 ​​is attached to the circumferential surface of the first shaft portion 15 so as to be located in the space 401 (see Figure 12) surrounded by the magnetic poles of the core body 400 when the rotary reciprocating drive actuator 1 is assembled.

[0089] The magnet 32 ​​is fixed so as to surround the outer circumference of the first shaft portion 15. Here, the magnet 32 ​​is firmly fixed to the central part of the first shaft portion 15. The magnet 32 ​​is firmly fixed to the first shaft portion 15 by, for example, applying adhesive to the entire portion that is externally fitted to the first shaft portion 15. In addition, a concave portion 153 (see Figures 6 and 13) is formed in the central part of the first shaft portion 15 to which the magnet 32 ​​is externally fitted. The concave portion 153 collects (releases) the adhesive applied between the magnet 32 ​​and the first shaft portion 15, preventing the adhesive from leaking out of the application area.

[0090] In this embodiment, the magnet 32 ​​is magnetized with different polarities, with a plane along the axial direction of the first shaft portion 15 as the boundary. That is, the magnet 32 ​​is a two-pole magnet magnetized so as to be equally divided into an S pole 32a and an N pole 32b. The number of magnetic poles of the magnet 32 ​​(two in this embodiment) is equal to the number of magnetic poles of the core body 400. Note that the magnet 32 ​​may be magnetized with two or more poles depending on the amplitude during movement. In this case, the magnetic poles of the core body 400 are provided corresponding to the magnetic poles of the magnet 32.

[0091] The polarity of the magnet 32 ​​is switched at the "magnetic pole switching section," which is the boundary portion 32c between the south pole 32a and the north pole 32b. The magnetic pole switching section 32c is formed as a groove extending through the axis on one end face of the magnet 32. When the magnet 32 ​​is held in the neutral position, the magnetic pole switching section 32c faces each of the magnetic poles.

[0092] If the magnetic pole switching section 32c is formed in a groove shape, the positional relationship of each component fixed to the first shaft section 15 can be adjusted using the groove of the magnetic pole switching section 32c as a reference during assembly or maintenance of the rotary reciprocating drive actuator 1. In particular, the position (orientation) of the mirror section 11 relative to the first shaft section 15 can be precisely and appropriately defined in accordance with the position of the magnetic pole switching section 32c of the magnet 32. For example, by applying a jig to the groove in the axial direction and fitting the projection of the jig into the groove, the rotation of the first shaft section 15 around its axis can be restricted. As a result, by simply restricting the rotation of the first shaft section 15 to a desired angular position suitable for attaching other components to the first shaft section 15, a reference position for attaching other components can be defined. In particular, precision is required for angle adjustment of the mirror relative to the poles of the magnet 32, but high-precision angle adjustment can be easily achieved.

[0093] In the neutral position, the magnetic pole switching section 32c of the magnet 32 ​​faces the magnetic pole directly, allowing the drive unit 4 to generate maximum torque and stably drive the movable body 10.

[0094] Furthermore, by configuring the magnet 32 ​​as a two-pole magnet, it becomes easier to drive the movable object with high amplitude in cooperation with the core body 400, and the driving performance can be improved. In other words, the mirror part 11, which is the movable object, can be driven at a wide angle. In this embodiment, the case in which the magnet 32 ​​has a pair of magnetic pole switching parts 32c has been described, but it may have two or more pairs of magnetic pole switching parts.

[0095] <Bottom cover 50 and top cover 60> The bottom cover 50 and top cover 60 shown in Figures 1-3, 5-8, 13, and 17 are preferably made of an electrically conductive material that is nonmagnetic and highly conductive, in which case they function as an electromagnetic shield.

[0096] The bottom cover 50 and the top cover 60 are positioned on both sides of the core assembly 40 in the axial direction (thickness direction), as shown in Figures 3 and 5 to 8, respectively, and close the core assembly 40 in the axial direction.

[0097] The bottom cover 50 and the top cover 60 can suppress the incidence of noise into the core assembly 40 and the emission of noise from the core body 400 to the outside.

[0098] The bottom cover 50 and top cover 60 are formed from a non-magnetic, electrically conductive, and highly thermally conductive material such as an aluminum alloy. Aluminum alloys offer a high degree of design flexibility, and the desired rigidity can be easily imparted to the bottom cover 50 and top cover 60.

[0099] Furthermore, the bottom cover 50 and the top cover 60 are fixed (for example, by screw fastening) by sandwiching the core assembly 40 in the axial direction and inserting the fastening member 18 through them. In the top cover 60, a fixing hole is formed in the counterbore portion 64 for inserting the fastening member 18.

[0100] 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 body 51, and in the cover body 51, an opening 53 is formed at the corner 510 where the sides 52 and 54 intersect orthogonally, through which the first shaft portion 15 is inserted. The opening 53 is positioned to communicate with the insertion hole 211a of the wall portion 211. The opening 53 is formed on the outer surface (one surface) of the bottom cover 50 at a position offset from the center of the surface toward the corner 510.

[0101] A bearing 24 is fitted into the opening 53 of the cover body 51 from the core assembly 40 side. The bearing 24 has a flange 244 on its outer circumference, which engages with the step (counterbore) of the opening 53. The flange 244 prevents the bearing 24 from coming out of the bottom cover 50 towards the mounting surface to the base portion 21. In this way, the bearing 24 restricts the axial outward movement of the bottom cover 50 by the flange 244 engaging with the step of the opening 53, that is, by engaging with the bottom cover 50 on the inside. The first shaft portion 15 inserted into the bearing 24 is positioned in the drive unit 4 so that it protrudes from a predetermined position on the bottom cover 50 and the mirror portion 11 is connected to it. The predetermined position is, as described above, a position shifted from the center of the outer surface of the bottom cover 50 toward the corner portion 510, and is an eccentric position on the bottom cover 50 in the direction from the center toward the corner portion.

[0102] As shown in Figures 8 and 13, the cover body 51 of the bottom cover 50 is provided with fixing holes 55, mounting holes 56 for fixing to the base portion 21, positioning holes 57, core positioning projections 58 and fixing holes 59.

[0103] The fixing hole 55 is used to fasten the fastening member 19, which is inserted into the fixing hole 432 of the core assembly 40. This fixes the core assembly 40 to the bottom cover 50. The fixing hole 59 is used to fasten the fastening member 18, which engages with the top cover 60, passes through the top cover 60, and is inserted through the core assembly 40. The top cover 60, core assembly 40, and bottom cover 50 are integrally attached to each other by the fastening member 18.

[0104] The mounting holes 56 are for fixing the bottom cover 50 and the drive unit 4 to the wall portion 211. The mounting holes 56 are formed in a direction perpendicular to the extending direction of the rod-shaped bodies 412a and 412b, and are positioned to sandwich the core assembly 40. The mounting holes 56 are located on another diagonal (another oblique line) extending in a direction intersecting the diagonal DL in the bottom cover 50, and are positioned to avoid the core assembly 40 (core body 400).

[0105] The mounting hole 56 is fastened to the fixing hole 211b (see Figure 4) of the wall portion 211 via the fastening member 16, and the bottom cover 50 and the drive unit 4 are fixed to the base portion 21. The drive unit 4 is fixed to the wall portion 211 with the first shaft portion 15 inserted through the insertion hole 211a of the wall portion 211.

[0106] The opening 53, fixing hole 55, mounting hole 56, positioning hole 57, and fixing hole 59, and the holes communicating therewith, are formed parallel to the axial direction of the first shaft portion 15. Since the assembly of each part, including the drive unit 4 and the base portion 21, etc., can be performed in one axial direction using the fastening members 16, 18, and 19, assembly efficiency can be improved.

[0107] Furthermore, as shown in Figures 6 and 8, a cylindrical positioning projection 588 is provided on the edge of the opening 53 on the back side of the cover body 51 of the bottom cover 50. The positioning projection 588 is fitted into the insertion hole 211a of the base portion 21. This allows the bottom cover 50 to be attached to the wall portion 211 after the positioning projection 588 has been fitted into the insertion hole 211a and the bottom cover 50 has been positioned and installed on the wall portion 211.

[0108] The core positioning projection 58 shown in Figure 13 engages with the core assembly 40 to position it when the bottom cover 50 and the core assembly 40 are combined. Specifically, the core positioning projection 58 protrudes axially from the edge of the opening 53 on the surface side of the cover body 51, from a position that straddles the opening 53.

[0109] The core positioning projection 58 is inserted between the rod-shaped bodies 412a and 412b and the inclined edges 422a and 422b, thereby engaging with the core assembly 40 and positioning the mounting position of the core assembly 40 relative to the bottom cover 50.

[0110] Preload springs 82 and 84 are provided inside the bottom cover 50, core assembly 40, and top cover 60 as preload units, which apply constant axial preload from within the drive unit 4 to the bearings 24 and 26 through which the first shaft portion 15 is inserted.

[0111] Figure 14 is an enlarged view of the preload section of the rotary reciprocating drive actuator. The preload spring 82, an example of the preload section shown in this figure, is a coil spring and is formed similarly to the preload spring 84. The preload spring 82 is a cylindrical coil spring with both ends 822 and 824 having the same diameter and spaced apart in a predetermined longitudinal direction. The preload spring 82 is positioned between the magnet 32 ​​and the bearing 24 in an axially contracted state and applies a constant preload to the bearing 24 so as to bias the bearing 24 in the axial direction. By applying preload, the preload spring 82 presses the bearing 24 from the inside of the drive unit 4 toward the other end 154. In other words, by applying preload, the preload spring 82 presses the bearing 24 from the inside of the drive unit 4 toward the other end 144 of the entire movable body including the second shaft section 14.

[0112] As shown in Figures 3 and 6, a preload spring 82 and a stopper 86 are externally fitted to the first shaft portion 15 through which the bearing 24 is inserted. The preload spring 82 presses against the bearing 24 via the stopper 86.

[0113] The preload spring 82 applies constant pressure preload to the bearing (especially the ball bearing) 24, thereby absorbing fluctuations in load or expansion and contraction of the first shaft 15 due to temperature differences between the first shaft 15 and the base 21 during rotation. As a result, the preload mechanism, which maintains constant pressure while appropriately changing the preload application position, prevents axial vibration of the first shaft 15. Therefore, compared to fixed-position preloading, high-speed rotational drive of the first shaft 15 can be achieved with lower vibration.

[0114] Furthermore, since the low friction and high reliability of the rotational drive of the first shaft portion 15 are maintained, stable drive can be achieved.

[0115] The stopper 86 restricts the axial deformation region of the preload spring 82 when the preload spring (coil spring) 82 presses the bearing 24 from the main body side of the drive unit 4 towards the wall 212 side (the other end side), preventing the preload spring 82 from being excessively compressed in the axial direction. In other words, the stopper 86 prevents the preload spring (coil spring) 82 that presses the bearing 24 from the main body side of the drive unit 4 towards the other end side from becoming less than its compressed length.

[0116] The stopper 86 is positioned between the preload spring 82 and the bearing 24. The stopper 86 has a concave portion, which is a cylindrical space between it and the first shaft portion 15, into which the spring, which is the preload spring 82, is inserted. One end of the preload spring (coil spring) 82 is housed in the concave portion, and the preload spring 82 presses against the bearing 24 through the concave portion of the stopper 86.

[0117] When the preload spring 82 contracts, it deforms axially within the concave portion of the stopper 86. Within the concave portion of the stopper 86, the preload spring 82 is allowed to deform to the point where the windings of the coils constituting the coil spring come into close contact with each other in the axial direction, and any further deformation is restricted by the stopper 86. In this way, the stopper 86 restricts the windings of adjacent coils in the preload spring 82 from coming into close contact with each other in the axial direction, so as not to fall below the contact length.

[0118] In the drive unit 4, the first shaft portion 15 is prevented from being pushed too far into the stopper 86, the preload spring 82 never falls below its compressed length, and malfunctions (including failures) of the preload spring 82 due to excessive pushing of the first shaft portion 15 are prevented. In the configuration where a stepped shaft is used as the first shaft portion 15, when the preload spring 82 presses against the bearing 24 via the stopper 86, the stopper 86 prevents the preload spring 82 from deforming outwards.

[0119] The preload spring 82 may be a conical coil spring 82A, as shown in Figure 15. The conical coil spring 82A has two ends 822A and 824A that are spaced apart in the axial direction and have different diameters. Compared to a cylindrical coil spring, when the windings of the coil constituting the conical coil spring 82A move in the axial direction, they overlap and come into close contact in the radial direction without overlapping in the axial direction. Therefore, even when the conical coil spring 82A is compressed, the windings of the coil do not come into close contact in the axial direction, and the contact height of the conical coil spring 82A is lower than that of a cylindrical coil spring. As a result, when the rotary reciprocating drive actuator 1 has a conical coil spring 82A, the axial length of the drive unit 4, and thus the rotary reciprocating drive actuator 1, can be shortened in the axial direction compared to when a cylindrical preload spring 82 is used.

[0120] The top cover 60, together with the bottom cover 50, sandwiches the core assembly 40 from both axial sides, covering the core assembly 40. The top cover 60 is integrally fixed by the fastening member 18, forming the drive unit 4.

[0121] The top cover 60 has a cover body 62 that covers the front end surface of the core assembly 40. The top cover 60 is configured as a covered cylindrical shape with a peripheral wall portion that protrudes from the outer peripheral edge of the cover body 62 toward the core assembly 40.

[0122] The cover body 62 has a shape that corresponds to the outer shape of the core assembly 40 when viewed from the axial direction, and is formed in a shape that includes a trapezoidal portion with an inclined edge. The cover body 62 is provided with an opening 63 and a through hole 66. The opening 63 is positioned in the cover body 62 so as to be coaxial with the opening 53 of the bottom cover 50 and the bearing 22 of the base portion 21.

[0123] A bearing 26, through which the first shaft portion 15 is inserted, is fitted into the opening 63 from the back side (core assembly 40 side). The opening 63 has a counterbore portion 64 (see Figure 6) on the back side which forms a step.

[0124] The terminals 49 are inserted through the through-hole 66 via the terminal support portions 464 of the bobbins 46a and 46b.

[0125] A terminal support portion 464 of the coil body may be fitted into the through hole 66. One end 492 of the terminal 49 protruding from the terminal support portion 464 is connected to the substrate 72, and power can be supplied to the coils 44a and 44b via the substrate 72 which is connected to the power supply unit. The power supply unit may also be provided on the substrate 72.

[0126] The back surface of the cover body 62 is provided with positioning parts (boss part 68, arc-shaped boss part 69) that engage with the core assembly 40 in the axial direction to prevent rotation around the axis and position it. The positioning parts (boss part 68, arc-shaped boss part 69) protrude from the core assembly 40 side (one end side) and fit into the core assembly 40.

[0127] The boss portion 68 enters the inner corner portion 4231 (see Figure 7) of the concave base portion 423 of the core assembly 40 and engages with it, thereby restricting the relative movement of the top cover 60 and the core assembly 40 around the first shaft portion 15.

[0128] The arc-shaped boss portion 69 fits into the gap in the core assembly 40, that is, the core groove portion 402 (see Figure 7), which is the gap between the inclined edges 422a and 422b and the magnetic poles of the rod-shaped bodies 412a and 412b. This restricts the relative axial radial movement of the top cover 60 and the core assembly 40 around the first shaft portion 15.

[0129] In this way, the cover body 62 of the top cover 60 can engage with the upper surface of the core assembly 40 at the boss portion 68 and the arc-shaped boss portion 69. This makes it easy to position the top cover 60 and the core assembly 40, and consequently to accurately join them together.

[0130] The core assembly 40 to which the top cover 60 is attached is positioned and fixed to the bottom cover 50 or a jig (not shown) via pins 37 during the installation process. The jig is used to attach the top cover 60 to the core assembly 40.

[0131] The boss portion 68 and the arc-shaped boss portion 69 allow the top cover 60 to be fitted and positioned in the upper part of the core assembly 40 where there are no pins 37. In this configuration, the pins 37 extend towards the top cover and do not pass through the top cover 60. Therefore, a circuit board 72, such as an intermediate circuit board, can be placed above the pins 37 on the top cover 60 (see Figure 6). In addition, a terminal 49 can be placed between the circuit board 72 and the pins 37. With this arrangement, when the top cover 60 is attached to the core assembly 40 in the axial direction, the terminal 49 can be connected to the circuit board 72 in the axial direction.

[0132] The bearing 26 rotatably supports the inserted first shaft portion 15 in the top cover 60. The bearing 26 has a flange 264 on its outer circumference, and the flange 264 engages with the counterbore portion 64 of the opening 63, that is, engages on the back surface of the top cover 60. This restricts the bearing 26 from moving axially outward from the back side of the wall portion 211 in the top cover 60.

[0133] The bearing 26, together with the bearing 24 provided in the bottom cover 50, supports the first shaft portion 15, which rotates on the same axis as the second shaft portion 14.

[0134] The bearing 26 is biased toward the opening 63 by the preload spring 84, and a constant preload is applied to it via the stopper 88, similar to the preload spring 82. The preload spring 84 is the same as the preload spring 82 and is a cylindrical coil spring as shown in Figure 14.

[0135] In this manner, the drive unit 4 is subjected to constant pressure preload so as to bias the bearings 24 and 26 on both outer sides in the axial direction of the first shaft portion 15, with the magnet 32 ​​in between.

[0136] Alternatively, a conical coil spring 82A may be used as the preload spring 84, for example, as shown in Figure 15. By using a conical coil spring 82A instead of the preload spring 84, the compressed length is shortened compared to when a cylindrical preload spring 84 is used, and the drive unit 4 and, consequently, the rotary reciprocating drive actuator 1 can be shortened in the axial direction.

[0137] Furthermore, of the movement of the movable body 10 relative to the base portion 21, movement toward the other end, i.e., the right side in Figure 3, is restricted by the rightward movement of the first shaft portion 15, which is restricted by the magnet 32 ​​via the preload spring 82 and stopper 86. Also, of the movement of the movable body 10 relative to the base portion 21, movement toward the one end 152, i.e., the left side in Figure 3, is restricted by the leftward movement of the second shaft portion 14, which is restricted by the shaft movement restricting part 23, such as an E-ring fitted to the second shaft portion 14. Due to these movement restrictions, the movable body 10 cannot be removed from the base portion 21.

[0138] The rotary reciprocating actuator 1 is used with the bottom 213 of the base 21 placed on the product. The back surface of the bottom 213 is the mounting surface 213a that contacts the product when the rotary reciprocating actuator 1 is installed on the product. The mirror section 11 reciprocates around the first shaft section 15 and the second shaft section 14, which are parallel to the mounting surface 213a.

[0139] Since the drive unit 4 is mounted in surface contact with the wall portion 211 which is perpendicular to the bottom portion 213, the bottom cover 50 is positioned so as to rise perpendicularly to the bottom portion 213 of the base portion 21 which serves as the mounting surface 213a.

[0140] The first shaft portion 15 and the second shaft portion 14 are arranged on the same axis, and the first shaft portion 15 is rotatably positioned on the outer surface of the bottom cover 50 or the wall portion 211 at a position spaced further from the installation surface 213a than the center of the outer surface of the wall portion 211. The position spaced further from the installation surface 213a is an eccentric position offset from the center of the outer surface of the wall portion 211, and is near the corner portion 210 formed by the edges 2111 and 2112, that is, near the corner portion 510 of the bottom cover 50.

[0141] [Magnetic circuit configuration of rotary reciprocating actuator 1] Figure 16 shows the operation of the rotary reciprocating actuator by the magnetic circuit of the rotary reciprocating actuator according to this embodiment.

[0142] When current is supplied to coils 44a and 44b, the first core 41 and second core 42, which include rod-shaped bodies 412a and 412b, are energized, and polarity corresponding to the direction of current flow is generated in the magnetic poles. As a result, magnetic force (attraction and repulsion) is generated between the magnetic poles at the tips of the rod-shaped bodies 412a and 412b and the magnet 32, causing the magnet 32 ​​to reciprocate and, in turn, to reciprocate and rotate the mirror portion 11 via the first shaft portion 15.

[0143] This operation will be explained in detail. In the rotary reciprocating drive actuator 1, when the coil 44 is not energized, the magnet 32 ​​is standard The magnetic attraction between the position holding unit 48 and the magnet 32, that is, the magnetic spring, causes the magnet 32 ​​to be positioned in the operating reference position.

[0144] In the normal state, that is, in the operating reference position, one of the magnetic poles (S pole 32a, N pole 32b) of the magnet 32 ​​is attracted to the reference position holding part 48, and the magnetic pole switching part 32c is positioned opposite the center position of the magnetic poles of the rod-shaped bodies 412a and 412b.

[0145] As shown in Figure 16, for example, in a configuration where the reference position holding part 48 is magnetized with a north pole on the opposing surface facing the magnet 32, a magnetic spring torque (indicated by arrow FM) is generated that rotates the magnet 32 ​​so as to attract the south pole (magnetic pole) 32a of the magnet 32.

[0146] When the magnet 32 ​​is in the operating reference position under normal conditions, the movable body 10 can be driven in the desired rotational direction and its torque can be maximized by exciting coils 44a and 44b according to the direction of energization of coils 44a and 44b.

[0147] When current is applied to coils 44a and 44b, the core assembly 40 is energized, and polarity corresponding to the direction of current application is generated in the magnetic poles. For example, as shown in Figure 16, when current is applied to coil 44, a magnetic flux is generated inside the core body 400, and the magnetic pole of rod-shaped body 412a becomes the north pole, and the magnetic pole of rod-shaped body 412b becomes the south pole.

[0148] As a result, the magnetic pole of the rod-shaped body 412a, which is magnetized to the north pole, attracts the south pole 32a of the magnet 32, and the magnetic pole of the rod-shaped body 412b, which is magnetized to the south pole, attracts the north pole 32b of the magnet 32. Then, a torque in the F direction is generated in the magnet 32 ​​around the axis of the first shaft portion 15, and the magnet 32 ​​rotates in the F direction. Consequently, the first shaft portion 15 also rotates in the F direction, and the mirror portion 11 fixed to the first shaft portion 15 also rotates in the F direction.

[0149] Next, when current is applied to the coil 44 in the reverse direction, the flow of magnetic flux generated inside the core body 400 becomes opposite to the direction shown in Figure 16, and the magnetic pole of the rod-shaped body 412a becomes the south pole, and the magnetic pole of the rod-shaped body 412b becomes the north pole. The magnetic pole magnetized to the south pole attracts the north pole 32b of the magnet 32, and the magnetic pole magnetized to the north pole attracts the south pole 32a of the magnet 32. Then, a torque -F opposite to the F direction is generated in the magnet 32 ​​around the axis of the first shaft portion 15, and the magnet 32 ​​rotates in the -F direction. Accordingly, the first shaft portion 15 also rotates, and the mirror portion 11 fixed to the first shaft portion 15 also rotates in the opposite direction as shown in Figure 16. The reciprocating rotational drive actuator 1 drives the mirror portion 11 to reciprocate rotation by repeating the above operations.

[0150] In practice, the rotary reciprocating actuator 1 is driven by an AC wave input to the coil 44 from a power supply unit (corresponding, for example, the drive signal supply unit 103 in Figure 18). In other words, the direction of current flow in the coil 44 is periodically switched. When the direction of current flow is switched, the magnetic attractive force between the reference position holding unit 48 and the magnet 32, that is, the restoring force of the magnetic spring (the magnetic spring torque FM shown in Figure 16 and the torque in the opposite direction, "-FM"), biases the magnet 32 ​​to return to the neutral position. As a result, the first shaft unit 15 (movable body 10) is subjected to alternating torques around the axis in the F direction and in the opposite direction to the F direction (-F direction). This causes the movable body 10 to rotate and reciprocate.

[0151] The driving principle of the rotary reciprocating actuator 1 is briefly described below. In the rotary reciprocating actuator 1 of this embodiment, the moment of inertia of the movable body 10 is J[kg·m 2 ], the torsional spring constant of the magnetic spring (rod-shaped bodies 412a, 412b, reference position holding part 48 and magnet 32) is K sp In this case, the movable body 10 has a resonant frequency F calculated by the following equation (1) relative to the fixed body 20. r It vibrates at [Hz].

[0152]

number

[0153] Since the movable body 10 constitutes the mass portion in the spring-mass vibration model, the coils 44a and 44b have a resonant frequency F of the movable body 10. r When an AC wave with a frequency equal to F is input to the movable body 10, the movable body 10 enters a resonant state. That is, the resonant frequency F of the movable body 10 is input to the coils 44a and 44b from the power supply unit. r By inputting an AC wave with approximately the same frequency, the movable body 10 can be vibrated efficiently.

[0154] The equations of motion and circuit equations showing the driving principle of the rotary reciprocating drive actuator 1 are shown below. The rotary reciprocating drive actuator 1 is driven based on the equation of motion shown in the following formula (2) and the circuit equation shown in the following formula (3).

[0155] [Number]

[0156] [Number]

[0157] That is, the moment of inertia J [kg·m 2 , rotational 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 appropriately changed within the range that satisfies formula (2). Also, voltage e(t) [V], resistance R [Ω], inductance L [H], back electromotive force constant K e [V / (rad / s)] can be appropriately changed within the range that satisfies formula (3).

[0158] Thus, in the rotary reciprocating drive actuator 1, when energizing the coils 44a and 44b with an alternating current corresponding to the resonance frequency F sp determined by the moment of inertia J of the movable body 10 and the spring constant K of the magnetic spring r , a large vibration output can be efficiently obtained.

[0159] According to the rotary reciprocating drive actuator of the present embodiment, the torque generation efficiency of the drive unit 4 can be increased to reciprocally rotate and drive the mirror unit 11 which is the movable object. Also, heat is difficult to transfer to the mirror unit 11 which is the movable object, and the flatness accuracy of the reflecting surface of the mirror unit 11 can be ensured. Further, the manufacturability is high, the assembly accuracy is good, and even if the movable object is a large mirror, it can be driven with a high amplitude.

[0160] The rotary reciprocating drive actuator 1 of this embodiment is capable of resonant drive, but non-resonant drive is also possible. Furthermore, ringing can be suppressed by increasing the damping coefficient using a damping section.

[0161] In the drive unit 4, the core assembly 40 is fixed to the surface of the rectangular bottom cover 50 together with the first shaft portion 15, so as to be positioned approximately diagonally DL. The top cover 60 is attached to the core assembly 40 so as to cover the inside of the core assembly 40.

[0162] The bottom cover 50 is fixed to the wall portion 211 by overlapping and making surface contact with it via fastening members 16 inserted into mounting holes 56 located on both sides of the core assembly 40. The bottom cover 50 is attached to the wall portion 211 such that its edges 52 and 54 coincide with the edges 2111 and 2112 of the wall portion 211. The core assembly 40 is positioned on or along the diagonal DL on the outer surface of the bottom cover 50.

[0163] The rod-shaped bodies 412a, 412b and the coil 44 are arranged so as to be inclined with respect to the edges 52, 2111 corresponding to the upper edge and the installation surface 213a corresponding to the lower edge. This allows for a longer coil length in the magnetic circuit compared to a configuration where the first shaft portion 15 is positioned in the center of the wall portion 211 with a width equal to the dimensions from the installation surface 213a to the edges 52, 2111.

[0164] Therefore, even if it is not possible to secure the coil length in either the vertical or horizontal direction of the product to be mounted, the coil 44 can be positioned along the diagonal DL of the bottom cover 50, thus ensuring the coil length.

[0165] Therefore, while reducing the height of the rotary reciprocating drive actuator 1, it is possible to secure a coil length sufficient for high-amplitude driving and achieve high torque output.

[0166] Furthermore, the core assembly 40 and the top cover 60 have a configuration that prevents rotation during installation. This configuration allows the coil length to be maintained at a predetermined length (a length that enables high torque output) without extending the pin 37 from the bottom cover 50, thus enabling high torque output. The edges 52 and 54 correspond to the edges 2111 and 2112 of the wall 211. As a result, even if the position in the wall 211 through which the first shaft portion 15 is inserted (insertion hole 211a) is offset from the center of the wall 211, the core assembly 40, and by extension the core body 400, can be suitably installed in the same manner.

[0167] Furthermore, the shafts (first shaft 15, second shaft 14) are positioned at the corners 510 of the bottom cover 50, that is, at the corners 210 of the wall portion 211. Therefore, by making the upper surface of the magnetic circuit, which is arranged diagonally along the diagonal DL (the upper surface of the upward slope of the diagonal magnetic circuit), the top surface of the product can be made to secure the magnetic path and reduce the height.

[0168] In this embodiment, the rotary reciprocating drive actuator 1 is provided with constant pressure preload on bearings 22, 24, and 26. The method for providing this constant pressure preload will be explained with reference to Figure 17.

[0169] Figure 17 illustrates how preload is applied to a rotary reciprocating actuator. In the rotary reciprocating actuator 1 shown in Figure 17, the first shaft portion 15 and the second shaft portion 14 are inserted through the bearings 22, 24, and 26 of the base portion 21 to which the drive unit 4 is assembled, and the shaft movement restricting portion 23 is not attached. I support it.

[0170] When the movable body 10 is rotatably mounted on the base portion 21 with preload applied, and the second shaft portion 14 does not have an axis movement restricting portion 23 attached, the first shaft portion 15 and the second shaft portion 14 are pulled toward the second shaft portion 14 against the biasing force of the preload spring 82.

[0171] In other words, in Figure 17, the first shaft portion 15 and the movable body 10 (including the second shaft portion 14) are pushed to the right (towards the wall portion 212) relative to the base portion 21. When the protruding end of the second shaft portion 14 is pulled in the X direction, the first shaft portion 15 is pressed in the pressing direction during assembly as shown in Figure 17, and in this state, the preload spring 82 biases the bearing 24 in the p1 direction. At this time, the bearing 22 is also pressed in the same direction.

[0172] In this state, when the shaft movement restricting part 23 is fitted onto the second shaft part 14, the movement of the second shaft part 14 in the -X direction is restricted, and the movable body 10 is fixed in a state where it is pulled toward the second shaft part 14. As a result, a restoring force acts on the preload spring 82, and the preload spring 82 presses the bearing 24 in the p1 direction, while the bearing 22 is subjected to a force in the p2 direction, resulting in a preloaded state.

[0173] Furthermore, as the second shaft portion 14 moves in the X direction, a force acts on the deformed preload spring 82 to restore its shape. A reaction force from the magnet 32 ​​is generated on the preload spring 82 on the first shaft portion 15, and a biasing force acts on the bearing 26 in the direction of arrow p2. As a result, constant preload is applied to each of the bearings 22, 24, and 26 of the rotary reciprocating drive actuator 1. Consequently, the preload portion (preload spring 82) that applies constant preload to bearing 24 applies a biasing force to bearing 22 toward one end of the second shaft portion 14.

[0174] Alternatively, when the movable body 10 is assembled to the base portion 21, that is, between the pair of wall portions 211 and 212, with the shaft movement restricting portion 23 removed, the first shaft portion 15 may be pulled toward the tip side (the drive unit 4 side, which is the left side in the plane of Figure 17). In this state, the shaft movement restricting portion 23 is fitted onto and fixed to the second shaft portion 14. As a result, the preload spring 84 that applies constant preload to the bearing 26 applies constant preload to the bearing 26 and also applies constant preload to the bearing 22 of the wall portion 212. In this way, the first shaft portion 15 is driven effectively by preventing shaft runout during rotation and suppressing noise and vibration via the movable body 10 and bearings 22, 24, and 26.

[0175] The rotary reciprocating actuator 1 of this embodiment has a movable body 10 having a second shaft portion 14 to which a mirror portion 11 is connected via mirror holders (holders) 12 and 13. The movable body 10 is connected to a first shaft portion 15 and an annular magnet 32 ​​fixed to the first shaft portion 15. The movable body 10 may also be configured to include the first shaft portion 15 and the magnet 32. The rotary reciprocating actuator 1 has a core assembly 40 having a core body 400 that includes a plurality of opposing magnetic poles on the outer circumference of the magnet 32 ​​and is arranged to surround the magnet 32, and coils 44a and 44b arranged in the core body 400.

[0176] The drive unit 4 has a bottom cover 50 and a top cover 60 positioned to sandwich the core assembly 40 in the axial direction, and the first shaft portion 15 through which it is inserted is rotatably supported by bearings 24 and 26, respectively.

[0177] In the base portion 21, the wall portion 212 supports the second shaft portion 14, which protrudes from the mirror portion 11, by inserting it into the bearing (wall bearing) 22 of the wall portion 212 so that it can rotate back and forth. The drive unit 4 applies preload to the bearings 24, 26 and the bearing (wall bearing) 22 by means of a pair of preload springs 82, 84 which are externally mounted on the first shaft portion 15 between the magnet 32 ​​and the bearings 24, 26, respectively.

[0178] Since preload springs 82 and 84 are provided, even when the rotary reciprocating drive actuator is cantilevered, the bearing 22 ensures shock resistance and vibration resistance while improving the axial runout accuracy of the second shaft portion 14 and suppressing noise and vibration. Furthermore, there is no need to separately provide a preload biasing member to apply preload to the bearing 22, which allows for a lower profile or miniaturization of the rotary reciprocating drive actuator or the device equipped therewith. Thus, the rotary reciprocating drive actuator 1 can generate high torque to achieve high amplitude and a low profile.

[0179] [Outline configuration of the scanner system] Figure 18 is a block diagram showing the main components of an example of a scanner system 100 having a rotary reciprocating actuator.

[0180] The scanner system 100 shown in Figure 18 includes a laser light-emitting unit 101, a laser control unit 102, a rotary reciprocating drive actuator 1, a drive signal supply unit 103, and a position control signal calculation unit 104.

[0181] The scanner system 100 scans an object using a rotary reciprocating actuator 1 capable of reciprocating rotation of the mirror unit 11 on a single axis. The rotary reciprocating actuator 1 also has an angle sensor unit as a rotation angle position detection unit 70 that detects the angle of the mirror unit 11, that is, the rotation angle of the first axis unit 15. The angle sensor unit detects the rotation angle of the movable body 10, which includes the magnet 32 ​​and the first axis unit 15. Based on the detection result of the angle sensor unit, the rotary reciprocating actuator 1 can control the rotation angle position and rotation speed of the movable body during operation, specifically the mirror unit 11 which is the movable object, via a control unit or the like. The rotation angle position detection unit 70 may be a magnetic or optical sensor.

[0182] The laser control unit 102 drives the laser light-emitting unit 101 and controls the laser that is emitted. The laser light-emitting unit 101 is, for example, an LD (laser diode) which serves as the light source and a lens for focusing the output laser. The laser light from the light source is emitted to the mirror unit 11 of the rotary reciprocating drive actuator 1 via the lens system.

[0183] The position control signal calculation unit 104 refers to the actual angular positions of the second shaft section 14 and the first shaft section 15 (mirror section 11) acquired by the rotational angular position detection unit 70 and the target angular position, and generates and outputs a drive signal to control the second shaft section 14 and the first shaft section 15 (mirror section 11) to the target angular position. For example, the position control signal calculation unit 104 generates a position control signal based on the acquired actual angular positions of the second shaft section 14 and the first shaft section 15 (mirror section 11) and a signal indicating the target angular position converted using sawtooth waveform data or the like stored in a waveform memory (not shown), and outputs it to the drive signal supply unit 103.

[0184] The drive signal supply unit 103 supplies a desired drive signal to the coils 44a and 44b of the rotary reciprocating drive actuator 1, thereby rotating and reciprocating the actuator 1 to scan the target object.

[0185] Embodiments of the present invention have been described above. It should be noted that the above description illustrates preferred embodiments of the present invention, and the scope of the present invention is not limited thereto. In other words, the description of the configuration of the apparatus and the shape of each part is merely an example, and it is clear that various modifications and additions to these examples are possible within the scope of the present invention. [Industrial applicability]

[0186] The rotary reciprocating actuator according to the present invention is easy to assemble and has the advantage of being able to output high torque, and is particularly useful for use in scanners that rotate mirrors. [Explanation of symbols]

[0187] 1 Rotary reciprocating actuator, 4 Drive unit, 10 Movable body, 11 Mirror part, 12, 13 Holder (mirror holder), 14 Second shaft part (shaft part), 15 First shaft part (shaft part), 16, 17, 18, 19 Fastening member, 20 Fixed body, 21 Base part, 22, 24, 26 Bearing, 23 Axis movement restricting part, 32 Magnet, 32a S pole (magnetic pole), 32b N pole (magnetic pole), 32b Magnetic pole, 32c Magnetic pole switching part, 37 Pin (pin member), 40 Core assembly, 41 First core (core), 42 Second core (core), 44, 44a, 44b Coil, 46a, 46b Bobbin, 48 Reference position holding part, 49 Terminal, 50 Bottom cover (mounting surface), 51, 62 Cover body, 52, 2111 Side (one side), 54, 2112 Side, 53 Opening, 55, 59 Fixing holes, 56 Mounting hole, 57 Positioning hole, 58 Positioning projection, 59 Fixing hole, 60 Top cover (lid), 63 Opening, 64, 212b Counterbore, 66 Through hole, 68 Boss (projection), 69 Arc-shaped boss (boss), 70 Rotation angle position detection unit, 72 Substrate, 82 Preload spring, 86, 88 Stopper, 100 Scanner system, 101 Laser emitter, 102 Laser control unit, 103 Drive signal supply unit, 104 Position control signal calculation unit, 144, 154 Other end, 152 One end, 153 Concave part, 210, 510 Corner part, 211 Wall part (mounting target part), 211a, 212a Through hole, 211b Fixing hole, 212 Wall part, 213 Bottom part, 213a Installation surface, 224, 244, 264 Flange, 400 Core body (core), 401 Space, 402 Core groove part, 412a, 412b Rod-shaped part, 413 Connecting edge part, 414 Stepped part, 422a, 422b Inclined edge part, 422c Top edge part, 422d Recess, 423 Bottom edge part, 424 Inner bottom surface, 431 Mounting hole, 432 Fixing hole, 433 Positioning hole, 462 Bobbin body, 464 terminal support part, 491 other end, 492 one end, 822, 822A, 824, 824A both ends, 588 positioning projection, 4231 inside corner

Claims

1. A plate-shaped mounting surface that is joined to the part to be mounted, A rotatable shaft portion protrudes from a predetermined position on the mounting surface and to which a movable object is connected, A magnet fixed to the outer circumference of the aforementioned shaft portion, A core assembly comprising a core having a pair of rod-shaped magnetic bodies having magnetic poles at their tips facing each other on the outer circumference of the magnet, and a frame-shaped magnetic body connected to the base ends of the pair of rod-shaped magnetic bodies to form a magnetic path surrounding the magnet and the magnetic poles, and a coil that generates a magnetic flux in the core by energizing the core to cause the shaft to reciprocate and rotate, A plate-shaped cover portion is inserted through one end of the shaft portion and covers the one end of the core assembly, It has, The predetermined position is an eccentric position on the mounting surface, in the direction from the center toward the corner. The core assembly is fixed to the mounting surface such that the pair of rod-shaped bodies are aligned along the diagonal lines passing through the corners. The cover portion has a boss portion that protrudes from the core assembly side and engages inside the core assembly to restrict rotation in the circumferential direction about the shaft portion. Rotary reciprocating actuator.

2. The core assembly is fixed to the mounting surface by inserting a pin member that passes through the mounting surface in the axial direction. The rotary reciprocating actuator according to claim 1.

3. The boss portion has an arc-shaped boss portion that protrudes toward the core assembly side around the opening through which the shaft portion is inserted in the lid portion, and engages with the inside of the core assembly around the shaft portion. The rotary reciprocating actuator according to claim 1.

4. The coil is arranged on the outer circumference of the central portion of each of the pair of rod-shaped bodies. The core assembly has terminal portions that are connected to the coil and are positioned close to the base end side of the pair of rod-shaped bodies relative to the coil. The pin member is inserted in the core assembly at a position where, when viewed in a plane perpendicular to the axial direction, the terminal portion overlaps with one end of the shaft portion and is spaced apart from the terminal portion. The rotary reciprocating actuator according to claim 2.

5. The lid portion has a circuit board, The terminal portion is provided protruding toward the cover portion and has one end that is connected to the circuit board. The rotary reciprocating actuator according to claim 4.

6. The movable object is a mirror that reflects scanning light. The rotary reciprocating actuator according to claim 1.

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