JP2024031438A - Rotation reciprocation drive actuator - Google Patents

Abstract

To preferably drive a movable object with a high amplitude.SOLUTION: A rotation reciprocation drive actuator includes: a mobile body that includes a shaft part to which a mobile object is connected on one end part side and a magnet fixed to the shaft part on the other end part side, and is supported around an axis to be reciprocation rotatable; a base part that includes a pair of wall parts that rotatably supports the shaft part via a bearing on the one end part side, and is arranged so as to nip the mobile object; a core assembly having a core body that includes a plurality of magnetic poles opposite to an outer periphery of the magnet so as to nip the magnet, a coil body that is wound around the core body, and makes the mobile body rotate in reciprocation by generating a magnetic flux that mutually acts with the magnet by power conduction, and a magnet position holding part that regulates a reference position of the reciprocation rotation by generating a magnetic suction force between itself and the magnets, and is attached to the other wall part of the pair of wall parts; and a sensor substrate which is attached to one wall part of the pair of wall parts, to which a sensor for detecting a rotation angle of the shaft part is mounted, and in which the sensor is arranged from the one end part side to the one wall part toward the one wall part side.SELECTED DRAWING: Figure 2

Description

The present invention relates to rotary reciprocating actuators.

Conventionally, rotary reciprocating actuators have been used as actuators for optical scanning devices such as multifunction devices and laser beam printers. Specifically, the rotary reciprocating drive actuator reciprocates the mirror of the scanner to change the reflection angle of the laser beam and achieve optical scanning of the target object.

A rotary reciprocating actuator of this type using a galvano motor is disclosed in Patent Document 1. Various types of galvano motors are known, including a type having the structure disclosed in Patent Document 1 and a movable coil type in which a coil is attached to a mirror.

In Patent Document 1, four permanent magnets are provided on a rotating shaft to which a mirror is attached so as to be magnetized in the radial direction of the rotating shaft, and a core having a magnetic pole around which a coil is wound is arranged so as to sandwich the rotating shaft. A beam scanner is disclosed.

Patent No. 4727509

By the way, in a rotary reciprocating drive actuator, as also described in Patent Document 1, an angle sensor is provided to detect the rotation angle of a rotation shaft connected to a mirror. The scanning accuracy of the scanner depends largely on the detection accuracy of this angle sensor. In order to improve the detection accuracy of the angle sensor, the installation position of the angle sensor must be adjusted with high precision so that the relative relationship between the angle sensor and other components of the rotary reciprocating drive actuator, such as the mirror, is determined. There is a need to.

If the angle sensor is not placed near the bearing that supports the rotating shaft, it will be difficult to accurately detect the rotation angle of the rotating shaft due to the influence of shaft wobbling. Furthermore, when the angle sensor is placed close to the motor, there is a problem in that it is difficult to perform suitable measurements due to the effects of electromagnetic noise, heat generation, etc. from the motor.

The present invention has been made in consideration of the above points, and provides a rotary reciprocating drive actuator that can more preferably drive a movable object with high amplitude.

One embodiment of the rotary reciprocating drive actuator of the present invention is
A movable body that has a shaft portion to which a movable object is connected at one end side and a magnet fixed to the shaft portion at the other end side, and is supported for reciprocating rotation around the shaft;
a base portion rotatably supporting the shaft portion via a bearing on the one end side and having a pair of walls arranged to sandwich the movable object;
a core body having a plurality of magnetic poles facing the outer periphery of the magnet so as to sandwich the magnet; and a magnetic flux that is wound around the core body and interacts with the magnet, which is generated by energization to cause the movable body to reciprocate. The coil body has a magnet position holding part that generates a magnetic attraction force between the coil body and the magnet to define a reference position of the reciprocating rotation, and is attached to the other wall of the pair of walls. a core assembly;
A sensor is mounted on one of the pair of walls and detects the rotation angle of the shaft, and the sensor is mounted on one of the two walls from the one end side with the sensor facing the one wall side. A sensor board placed on the wall,
Adopt a configuration that includes the following.

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

FIG. 1 is an external perspective view of a rotary reciprocating drive actuator according to an embodiment of the present invention. FIG. 3 is a vertical cross-sectional view passing through the axis of the same-rotating reciprocating actuator. FIG. 3 is an end view taken along line AA in FIG. 2 with the left side member removed from the front end surface of the drive unit. FIG. 3 is an exploded perspective view of a rotary reciprocating actuator. An enlarged view of the preload spring. The figure which shows the wave spring which is a modification of the spring for preload. FIG. 3 is an exploded perspective view of the drive unit. A perspective view of a coil body. Exploded view of the coil body. FIG. 3 is a perspective view showing a state of wiring of coils in a coil body. FIG. 3 is a front perspective view of the bottom cover. FIG. 3 is an external perspective view of an angle sensor section in a rotary reciprocating actuator. FIG. 3 is an exploded perspective view of the front side of the angle sensor section. FIG. 3 is an exploded perspective view of the back side of the angle sensor section. FIG. 4 is a diagram for explaining the operation of the magnetic circuit of the rotary reciprocating drive actuator. FIG. 3 is an external perspective view of Modification 1 of the rotary reciprocating drive actuator. FIG. 6 is a vertical cross-sectional view showing a first modification of the rotary reciprocating drive actuator. FIG. 6 is an exploded perspective view of Modification 1 of the rotary reciprocating drive actuator. FIG. 7 is a perspective view of a wall portion on the front side of Modification 1 of the rotary reciprocating drive actuator. FIG. 3 is an exploded perspective view of a sensor section disposed on a wall on the same end side. FIG. 1 is a diagram showing a main part configuration of a scanner system using a rotary reciprocating actuator. 22A and 22B are a front view and a right side view of Modification Example 1 of the magnet. 23A and 23B are a front view and a right side view of magnet modification 2. 24A and 24B are a front view and a right side view of Modification Example 3 of the magnet. 25A and 25B are a front view and a right side view of Modification Example 4 of the magnet. FIG. 7 is a diagram illustrating a core assembly of a rotary reciprocating drive actuator having a magnet modification 4;

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an external perspective view of a rotary reciprocating drive actuator 1 according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view passing through the axis of the rotary reciprocating drive actuator 1. Further, FIG. 3 is an end view of the section taken along the line A-A in which the left side member is removed from the front end surface so that the inside of the drive unit 4 can be seen in FIG. 2, and FIG. FIG.

The rotary reciprocating drive actuator 1 is used, for example, in a LiDAR (Laser Imaging Detection and Ranging) device. Note that the rotary reciprocating drive actuator 1 is also applicable to optical scanning devices such as multifunction devices and laser beam printers.

The rotary reciprocating drive actuator 1 is roughly divided into a movable body 10, a base portion 21 that rotatably supports the movable body 10 and has an angle sensor unit 70 attached thereto, and a rotary reciprocating drive actuator 1 that reciprocates the movable body 10 with respect to the base portion 21. The drive unit 4 includes a drive unit 4 that rotates. The base portion 21 and the drive unit 4 constitute a fixed body 20 that supports the movable body 10 in a reciprocating manner.

Further, in the rotary reciprocating drive actuator 1, the movable body 10 is attached to the base portion 21 to constitute the main body unit 2, and the rotary reciprocating drive actuator 1 has the drive unit 4 at one end of the main body unit 2.

As shown in FIG. 1, in the rotary reciprocating actuator 1, the main body unit 2, in which the movable body 10 is attached to the base portion 21, and the drive unit 4 are joined by a fastening member 81. Note that the fixing member 81 may be any member as long as it can fix the main body unit 2 and the drive unit 4 together, and for example, male threads such as screws and screws, or bolts and nuts may be used.

As shown in FIG. 4, the movable body 10 includes a rotating shaft 13, a mirror portion 12, and a movable magnet (hereinafter simply referred to as "magnet") 32. Note that the magnet 32 will be explained in detail together with the drive unit 4, which will be described later.

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

The base portion 21 includes a flat bottom portion 213 and a pair of wall portions 211 and 212 spaced apart from each other. The bottom portion 213 has a flat plate shape and is provided to extend in the axial direction, and a pair of wall portions 211 and 212 are erected at both ends of the bottom portion 213 so as to face each other. The base portion 21 is formed into a substantially U-shape (U-shape) in cross section by a bottom portion 213 and a pair of wall portions 211 and 212.

The pair of wall portions 211 and 212 each have a rectangular plate shape, and insertion holes 211a and 212a are formed in the center portions thereof (see FIG. 4). Bearings 22 and 23 are fitted into the insertion holes 211a and 212a, and the rotating shaft 13 is inserted through the bearings 22 and 23.

Note that the insertion holes 211a and 212a are provided with counterbore portions having a larger diameter than the portions that penetrate through the opening edges of the wall portions 211 and 212 on the axially outer sides, respectively. The flanges 224 and 234 of the bearings 22 and 23 fit into the counterbore portions.

In the bearings 22 and 23, flanges 224 and 234 are provided at the opening edges on one side of the donut-shaped bearing bodies 222 and 232, respectively. The flanges 224 and 234 fit into the counterbore portions by fitting the bearings 22 and 23 into the insertion holes 211a and 212a of the walls 211 and 212 of the base portion 21 from the outside in the axial direction. The bearings 22 and 23 are fixed to the base portion 21 by press fitting or the like in a state where the bearings 22 and 23 are prevented from coming off in the fitting direction.

As a result, the bearing bodies 222, 232 of the bearings 22, 23 do not protrude outward from the walls 211, 212 with respect to the base part 21, and the walls 211, 212 of the base part 21 are made thinner. The overall length of the reciprocating drive actuator 1 can be shortened and the size can be reduced.

Further, the flanges 224, 234 of the bearings 22, 23 are fitted into counterbore portions on the axially outer sides of the insertion holes 211a, 212a (on the outer surfaces of the walls 211, 212). Thereby, during assembly of the main body unit 2, the fitted state of the flanges 224, 234 and the insertion holes 211a, 212a can be easily viewed and measured from the outside of the walls 211, 212.

The bearings 22 and 23 may be configured with a rolling bearing (for example, a ball bearing) or a sliding bearing for the base portion 21. For example, if the bearings 22 and 23 are rolling bearings, the coefficient of friction is low and the rotating shaft 13 can be rotated smoothly, thereby improving the driving performance of the rotary reciprocating drive actuator 1. Thereby, the rotating shaft 13 is rotatably attached to the base part 21 via the bearings 22 and 23, and the mirror part 12, which is a movable object, is arranged between the pair of wall parts 211 and 212. .

The rotating shaft 13 is inserted through the bearings 22 and 23, and both ends of the rotating shaft 13 protrude outward from each of the bearings 22 and 23 in the axial direction. The bearings 22 and 23 support the rotating shaft 13 on the base portion 21 so as to be rotatable around the shaft.

A movable mirror portion 12 is fixed to one end portion 131 of the rotating shaft 13 at a portion inserted between the pair of wall portions 211 and 212 of the base portion 21, and a movable mirror portion 12 is fixed to the other end portion 132 side of the rotating shaft 13. , a magnet 32 is fixed. As a result, the rotating shaft 13 is pivotally supported by the pair of wall portions 211 and 212 of the base portion 21. The base part 12 supports the mirror part 12 disposed between the pair of walls 211 and 212 from both sides via the rotating shaft 13, so the mirror part 12 is supported by the rotating shaft supported in a cantilevered manner. It can support the part 12 more firmly than the structure that supports it, and has improved impact resistance and vibration resistance.

The magnet 32 is disposed within a drive unit 4, which will be described later, and is driven to reciprocate and rotate by magnetic flux generated by the drive unit 4. Note that the rotation shaft 13 causes the mirror portion 12 to reciprocate due to mutual electromagnetic action between the drive unit 4 and the magnet 32.

In the rotating shaft 13, a retaining portion (retaining ring) 14 is fitted into a fitting groove 133 at one end 131 that protrudes outside the bearing 23, and this retaining portion 14 allows the rotating shaft 13 to Movement to is regulated. Further, the rotating shaft 13 has one end 131 inserted through the wall 212 on the one end side, and is connected to the angle sensor section 70 on the outer surface side of the wall 212. The angle sensor section 70 detects the angle of the rotating shaft 13, and is arranged in the rotary reciprocating drive actuator 1 so that the mirror section 12 and the drive unit 4 are sandwiched therebetween. That is, the angle sensor section 70 is spaced apart from the magnetic circuit of the drive unit 4 and arranged near the bearing 23. Details of this angle sensor section 70 will be described later.

A cylindrical stopper part 15 is externally inserted into the rotating shaft 13 at a portion between the mirror holder 122 of the mirror part 12 and the wall part 212 on the one end part 131 side of the pair of wall parts.

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

The stopper portion 15 prevents the rotary shaft 13 from coming off from the bearing 23 toward one end in the axial direction, that is, to the outside through the mirror portion 12 .

The stopper part 15, together with the stopper part 14, regulates the axial movement of the movable body 10 including the mirror part 12, the rotating shaft 13, and the magnet 32 within a predetermined range including tolerances, etc. It is prevented from coming off from the portion 21.

The rotating shaft 13 is disposed on the base portion 21 such that the other end portion 132 of the base portion 21 passes through the bearing 22 and projects from the wall portion 211 to the outside of the base portion 21 . A portion protruding from the wall portion 211 is inserted into the drive unit 4.

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

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

The preload spring 35 expands and contracts in the axial direction to bias the bearing 22 in the axial direction.
For example, as shown in FIG. 5, the preload spring 35 has a predetermined length L1 corresponding to the space in which the preload spring 35 is arranged, and has flat surfaces formed at both ends spaced apart in the predetermined length direction. It is a cylindrical coil spring.

The preload spring 35 is disposed so as to be fitted onto the rotating shaft 13 and biases the magnet 32 in a direction away from the bearing 22 that fits into the wall portion 211 .
The preload spring 35 is interposed between the annular receiving portion 37 adjacent to the magnet 32 and the bearing 22 with the rotating shaft 13 inserted therethrough.

The preload spring 35 applies a constant preload to the bearing 22 . The preload spring 35 applies a constant preload to the bearing 22, so that the spring absorbs changes in load and expansion and contraction of the rotating shaft 13 due to temperature differences between the rotating shaft 13 and the base part 21, and reduces the amount of preload. It is possible to obtain a stable amount of preload with little fluctuation. Therefore, the preload spring 35 prevents high-speed rotation of the rotary shaft 13 and axial vibration of the rotary shaft 13, and can be driven to rotate at a high speed compared to fixed position preload, and can prevent axial vibration. .

The preload spring 35 can maintain low slidability and high reliability of the rotational drive of the rotating shaft 13 by applying preload to the bearings (especially ball bearings) 22 and 23, and can perform stable drive. .

Note that it is desirable that the preload spring 35 has a structure in which it comes into contact with a strongly fixed component and receives preload from the component. The annular receiving portion 37 is a press-fit ring, and is fixed to the rotating shaft 13 by being press-fitted into the outer peripheral portion of the rotating shaft 13 .

The annular receiving portion 37 receives one end of the preload spring 35 that contacts the bearing 22 on one end side, thereby preventing direct impact from being applied to the magnet 32, which is an adhesively fixed component. This prevents unnecessary force from being applied to the magnet 32 and improves reliability.

Further, since the preload spring 35 is arranged inside the rotary reciprocating drive actuator 1, a stable preload design can be ensured without being influenced by the outside of the rotary reciprocating drive actuator 1.

In addition, the preload spring 35 is replaced with a cylindrical coil spring made of a round steel wire wound spirally, and a plate steel wire is wound spirally in the direction of expansion/contraction, that is, as a spring with a low height. Alternatively, a wave spring may be used which is wound in an annular shape and has waves added thereto.

For example, as the preload spring 350 having a shorter axial length than the cylindrical coil spring having the axial length L1 as the preload spring 35, a preload spring 350 as a wave spring shown in FIG. 6 may be used. .

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

When the length L0 of the wall portion 211 and the annular receiving portion 37 is in the range of L2<L0<L1, the preload springs 350 are stacked in plural in the direction of the length L2. This allows you to change the length of the expansion/contraction.

In this way, the preload springs 35 and 350 can be appropriately changed to adjust the preload force depending on the location where they are installed or the object of the preload, so that they can rotate at a suitable high speed, prevent vibrations in the axial direction, and drive stably. Can be done.

<Drive unit 4>
The drive unit 4 shown in FIGS. 2 to 4 and 7 is provided at one of both ends of the base portion 21 that are spaced apart in the axial direction, and constitutes a part of the fixed body 20. The drive unit 4 is arranged to sandwich the base part 21 between the angle sensor part 70 in the axial direction. The drive unit 4 constitutes a drive section 30 together with the magnet 32, and moves the movable body 10. Drive unit 4 includes a bottom cover 50, a core assembly 40, and a top cover 60. The drive unit 4 is formed, for example, in the shape of a rectangular parallelepiped that is square in front view.

<Core assembly 40>
The core assembly 40 shown in FIG. 3, FIG. 4, and FIG. have

In this embodiment, the core assembly 40 is formed into a rectangular frame block shape (more specifically, a rectangular parallelepiped shape) with magnetic poles 410a and 410b arranged inside. The core assembly 40 has a frame-shaped outer peripheral portion and is formed so as to surround magnetic poles 410a and 410b arranged inside the outer peripheral portion. For example, the core assembly 40 extends by folding back from each of the magnetic poles 410a and 410b that sandwich the magnet 32 within a rectangular area of the wall surface of the wall portion 211 of the base portion 21 when viewed from the axial direction, and surrounds the magnetic poles 410a and 410b. Forms one magnetic path.

<Core body 400>
The core body 400 constitutes a magnetic circuit including a magnetic path arranged so as to surround the magnet 32. The core body 400 includes a first core 41 having an integral structure including a plurality of magnetic poles 410a, 410b and a C-shaped magnetic path portion (a connecting side portion 412 and a side portion 413), and a side portion 413 of the first core 41. It has a second core 42 disposed so as to span between one end portions of the core and a frame-shaped third core 43. The core body 400 is formed by magnetically coupling the first to third cores into one piece.

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

<First core 41>
The first core 41 includes a rod-shaped portion 411 (411a, 411b), a connecting side portion 412, and a side portion 413. The first core 41 has opposing magnetic poles 410a and 410b at its tips, respectively, and a plurality of rod-shaped parts 411 (411a, 411b) arranged parallel to each other. A connecting side portion 412 extending perpendicularly to the extending direction thereof is connected to the base end portion of the rod-like portion 411 (411a, 411b). Both sides 413a and 413b are vertically protruded from both ends of the connection side 412, respectively. The connecting side portion 412 is provided with a commutative pole portion 414 extending between the rod-like portions 411a and 411b and parallel to the rod-like portions 411a and 411b.

The rod-like portions 411 (411a, 411b), the connecting side portions 412, the side portions 413 (413a, 413b), and the commutating pole portion 414 are integrally structured, and the first core 41 has a comb-teeth shape.

A magnetic pole is disposed on the side surface of the tip of each of the rod-shaped parts 411a, 411b, and bobbins 46, 47 are inserted on the proximal end side of the outer periphery of the rod-shaped parts 411a, 411b. Thereby, the coils 44 and 45 are arranged so as to wind around the rod-shaped parts 411a and 411b.

When the coils 44 and 45 are excited by energizing, the magnetic poles at the tips of the rod-shaped portions 411a and 411b have polarities depending on the direction of energization. The magnetic poles are each arranged to face the magnet 32, and each magnetic pole has a shape that curves along the outer peripheral surface of the magnet 32. These curved shapes are arranged, for example, so as to face each other in a direction perpendicular to the extending direction of the rod-like portions 411a and 411b.

The rod-shaped portions 411a and 411b have external dimensions that allow the bobbins 46 and 47 to be inserted from the tip side, for example. As a result, the bobbins 46 and 47 are extrapolated from the ends of the rod-like parts 411a and 411b in the extending direction, that is, from the ends of the magnetic poles 410a and 410b, and the bobbins 46 and 47 are inserted at the base end side of the rod-like parts 411a and 411b. can be positioned to surround the The extrapolated bobbins 46 and 47 are arranged between the side portion 413 and the interpolation portion 414, respectively.

The connecting side portion 412 constitutes one side of the rectangular core body 400, connects the rod-like portions 411a and 411b at their base ends, and extends in a direction perpendicular to the parallel direction of the rod-like portions 411a and 411b. It is set up.

The connecting side portion 412 mainly connects the base end portions of the rod-shaped portions 411a, 411b and both side portions 413a, 413b. Although both sides 413a and 413b are preferably in close contact with both ends of the second core 42, here, there is a gap between each of both sides 413a and 413b and each of both ends of the second core 42. They are arranged so that there is a gap.
The connecting side portion 412 and both side portions 413a and 413b are provided so as to be laminated together with the second core 42 and in close contact with the third core 43 in the axial direction.

The commutative pole part 414 is arranged to face the rotational angle position holding part 48 , and when the magnet 32 attracts the rotational angle position holding part 48 , it attracts another pole of the magnet 32 and maintains the attraction state with the rotational angle position holding part 48 . Reinforce.

Specifically, the commutating pole part 414 is made of a magnetic material, and is arranged, for example, to surround the magnet 32 on all sides together with the magnetic poles 410a, 410b and the rotation angle position holding part 48.
The commutative pole part 414 generates a magnetic attraction force with the magnet 32 (more specifically, the pole 32b), and in the magnet 32, the pole 32b, which is different from the pole 32a that is attracted to the rotation angle position holding part 48, Move it to the opposite position. Through this action, the commutating pole portion 414 offsets the axial and radial load acting on the movable body 10 due to the magnetic attraction force in the rotation angle position holding portion 48 . Note that "to offset the load in the radial direction of the shaft" also includes "to offset the load in the radial direction of the shaft".

In addition, the commutative pole surface that faces the outer circumferential surface of the magnet 32 in the commutative pole part 414 is a curved surface corresponding to the shape of the outer circumferential surface of the magnet 32, and there is a uniform gap over the entire surface between it and the outer circumferential surface of the magnet 32. has. In addition, since the commutating pole part 414 is arranged in the core assembly 40 so as to surround the magnet 32 together with the rotational angle position holding part 48, it is laid out in the minimum space, and the size is further reduced. A rotary reciprocating actuator 1 can be realized.

<Second core 42>
The second core 42, together with the first core 41, constitutes a magnetic path arranged so as to surround the magnetic poles at the tips of the rod-shaped parts 411a and 411b from all sides. The second core 42 is formed into a prismatic shape, and forms a magnetic path through which magnetic flux passes through the magnetic poles 410a and 410b when the coils 44 and 45 are energized.

The second core 42 has the same thickness (length in the axial direction) as both sides 413a and 413b.
The second core 42 is inserted through a fastening member 86 that is inserted into a mounting hole (fastening hole) 402 similar to the mounting hole (fastening hole) 402 provided at both ends of the connection side of the first core 41. The third core 43 is fixed to the bottom cover 50 and the top cover 60 in close contact with the third core 43 (see FIG. 13). The attachment hole 402 has the same diameter as the through hole 54 of the bottom cover 50 and is formed to extend parallel to the rotating shaft 13 .

A rotation angle position holding section 48 is attached to the second core 42 at a central portion in the extending direction and at a portion facing the magnet 32 . Another core is arranged so as to be joined to both ends of the second core 42, and the second core 42 is arranged at a position surrounding the magnet 32 and the magnetic poles 410a and 410b with the other core.

<Third core 43>
The third core 43, together with the connecting side portion 412 and side portion 413 of the first core 41, and the second core 42, forms a magnetic path that surrounds the plurality of magnetic poles and connects the plurality of magnetic poles.
The third core 43 has a rectangular frame plate shape and is attached in surface contact with the rectangular frame portion formed by both the first core 41 and the second core 42 .

Specifically, the third core 43 faces the connecting side portion 412 and both side portions 413a and 413b of the first core 41 in the extending direction of the rotating shaft 13, and makes surface contact with each other. In addition, the third core 43 is assembled to the first core 41 with the plurality of magnetic poles of the rod-shaped portions 411a, 411b of the first core 41 positioned around the rotating shaft 13. Further, the third core 43 faces and makes surface contact with the second core 42 in the extending direction of the rotating shaft 13.

Thereby, the third core 43 is arranged around the rotating shaft 13 so as to surround the magnetic poles of the rod-shaped parts 411a and 411b and the coils 44 and 45, and forms a seamless magnetic path around the rotating shaft 13. The first to third cores 41 to 43 have surrounding parts that surround the coils 44 and 45, and from one magnetic pole, the first core 41 + the third core 43, the third core 43, the third core 43 + the second core 42 , a flow of magnetic flux can be formed that passes through the third core 43 + the other magnetic pole of the first core 41 in this order. Furthermore, since the first to third cores 41 to 43 surround the magnetic poles and the magnet 32 between the magnetic poles in an annular manner, it is possible to prevent contact with the coils 44 and 45 from the outside.

When the drive unit 4 is assembled, the rotating shaft 13 is inserted into the space surrounded by the magnetic poles. Further, a magnet 32 attached to the rotating shaft 13 is located in this space, and a magnetic pole faces the magnet 32 at a precise position via an air gap G.

The magnet 32 is a ring-shaped magnet in which south poles 32a and north poles 32b are alternately arranged in the circumferential direction. The magnet 32 is attached to the circumferential surface of the rotating shaft 13 so as to be located in a space surrounded by the magnetic poles 410a and 410b of the core body 400 when the rotary reciprocating drive actuator 1 is assembled. The magnet 32 is fixed so as to surround the outer periphery of the rotating shaft 13. When the coils 44 and 45 are energized, the first core 41, second core 42, and third core 43 including the rod-like portions 411a and 411b are excited, and the magnetic poles 410a and 410b have polarities according to the direction of energization. As a result, magnetic force (attractive force and repulsive force) is generated between the magnetic poles 410a, 410b and the magnet 32.

In this embodiment, the magnets 32 are magnetized to different polarities with a plane along the axial direction of the rotating shaft 13 as a 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 410a and 410b of the core body 400. Note that the magnet 32 may be magnetized to have two or more poles depending on the amplitude during movement. In this case, the magnetic pole portion of the core body 400 is provided corresponding to the magnetic pole of the magnet 32.

<Magnet 32>
The polarity of the magnet 32 is switched at boundary parts 32c and 32d (hereinafter referred to as "magnetic pole switching section") between the S pole 32a and the N pole 32b. The magnetic pole switching parts 32c and 32d are formed in one end surface of the magnet 32 in the shape of a groove extending through the axis. The magnetic pole switching parts 32c and 32d directly face each of the magnetic poles 410a and 410b when the magnet 32 is held at the neutral position. In addition, the magnetic pole switching parts 32c and 32d function as a reference for positioning the components of each part when assembling the rotary reciprocating drive actuator 1.

In particular, since the magnet 32 is fixed to the rotating shaft 13, the rotation of the magnet 32 is restricted by applying a jig to the grooves of the magnetic pole switching parts 32c and 32d in the axial direction, and the mirror part 12 and the sensor component are You can decide by adjusting the positional relationship. In addition, since it can be defined based on the rotation axis 13 that is the center of the rotary reciprocating drive actuator 1, the dimensions of other parts can be easily set and manufactured with high precision.

If the magnetic pole switching parts 32c and 32d are formed in the shape of a groove, the positional relationship of each component fixed to the rotating shaft 13 can be adjusted using this groove as a reference during assembly or maintenance of the rotary reciprocating drive actuator 1. can. In particular, in accordance with the positions of the magnetic pole switching parts 32c and 32d of the magnet 32, the position of the mirror part 12 with respect to the rotating shaft 13, the mounting position of the encoder of the angle sensor part 70, etc. can be suitably and precisely defined. For example, by applying a jig to the groove in the axial direction and fitting a protrusion into the groove, the rotation of the rotating shaft 13 around the axis is restricted and immobilized, and the reference position of other components attached to the rotating shaft 13 is set. Become. In particular, precision is required to adjust the angle of the mirror relative to the pole of the magnet 32, and this is possible.

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

Furthermore, by configuring the magnet 32 as a bipolar magnet, it becomes easier to drive the movable object with high amplitude through cooperation with the core body 400, and the drive performance can be improved. In other words, the movable mirror portion 12 can be driven at a wide angle. In the embodiment, a case has been described in which the magnet 32 has a pair of magnetic pole switching parts 32c and 32d, but it may have two or more pairs of magnetic pole switching parts.

<Coil body (coil and bobbin)>
The coils 44 and 45 are wound around cylindrical bobbins 46 and 47. A coil body consisting of the coils 44, 45 and bobbins 46, 47 is inserted onto the rod-shaped parts 411a, 411b of the first core 41, so that the coils 44, 45 are arranged so as to wind around the rod-shaped parts 411a, 411b. be done. In this way, the coils 44 and 45 are arranged adjacent to the magnetic poles at the tips of the rod-shaped parts 411a and 411b.

The winding directions of the coils 44 and 45 are set so that, when energized, magnetic flux is suitably generated from one of the plurality of magnetic poles of the first core 41 toward the other.

FIG. 8 is a perspective view of the coil body, FIG. 9 is an exploded view of the coil body, and FIG. 10 is a perspective view showing how the coils are connected in the coil body.

Since the structure of the coil body which is the bobbin 46 around which the coil 44 is wound and the bobbin 47 around which the coil 45 is wound is the same, the coil body having the bobbin 46 around which the coil 44 is wound will be explained. A description of the coil body including the coil 45 and bobbin 47 will be omitted.

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

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

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

The terminal 496 has an L-shape, and connects the end of the coil 44 by wrapping it around one side 4962 , and the base end of the other side 4964 is inserted into and supported by the terminal support 494 . The distal end side of the terminal protrudes from the terminal support portion 494 to the outside.

The tip side of the other side 4964 is connected to an external device that supplies power to the coil 44 or to the ends of adjacent coils. In this embodiment, the terminal 496 has one side 4962 extending parallel to the axial direction of the coil 44 and the other side 4964 extending perpendicular to the axial direction of the coil 44 .

The coil body 49 is arranged such that one side 4962 of the terminal 496 extends in the opening direction of the opening of the bobbin part 492, and the other side 4964 extends in the direction in which the flange of the bobbin part 492 extends. It is located.

In one side portion 4962, the coil wires at both ends of the coil 44 are connected to each other by a connection portion H made of solder or the like.

In this way, the terminal 496 is L-shaped, and the coil winding is connected to one side 4962 (connection H which is a fillet), and the other side 4964 is joined to the sensor board 72. Ru.

Since the terminal 496 is L-shaped, it can be connected separately on the sensor board connection side and the coil connection side, which is particularly useful when forming the connection part (fillet) H for connecting the coil windings with solder. This can be easily done without interference from solder or windings.

That is, even if the work of connecting the sensor board 72 and the work of fixing the windings of the same terminal 496 occur, the process of connecting the wires to the board may be hindered, such as adhesion of solder when making the windings conductive. Never. The connection between the sensor board 72 and the terminal 496 can be made by arranging the sensor board 72 in the axial direction with respect to the drive unit 4, so that it can be positioned and prevent contamination. Easy to place.

<Rotation angle position holding section (magnet position holding section) 48>
The rotation angle position holding section 48 shown in FIGS. 2 to 4 is incorporated into the core assembly 40 so as to face the magnet 32 with an air gap G in between when the rotary reciprocating drive actuator 1 is assembled. The rotational angle position holding section 48 is attached to the second core 42, for example, with a magnetic pole facing the magnet 32.

The rotation angle position holding unit 48 uses, for example, a magnet with its magnetic pole facing the magnet 32 to generate a magnetic attraction force between the magnet 32 and attract the magnet 32. That is, the rotational angle position holding portion 48 forms a magnetic spring between the rod-shaped portions 411a and 411b and the magnet 32. This magnetic spring maintains the rotational angular position of the magnet 32, that is, the rotational angular position of the rotating shaft 13, at a neutral position in a normal state (de-energized state) when the coils 44 and 45 are not energized. .

At this time, the magnetic pole 32b (N pole shown in FIG. 3) opposite to the magnetic pole 32a (S pole in FIG. 3) of the magnet 32 that attracts the rotational angle position holding part 48 is connected to the first core 41 which is the adjacent magnetic body. The commutative pole part 414 is attracted. Thereby, the magnet 32, that is, the mirror portion 12, which is a movable object, is more effectively held at the neutral position.

The neutral position is the reference position of the reciprocating rotation movement of the magnet 32, that is, the center position of reciprocating rotation (oscillation), and the position where the same rotation angle is achieved when rotating left and right around the axis during reciprocating rotation. It is. When the magnet 32 is held in the neutral position, the magnetic pole switching parts 32c and 32d of the magnet 32 directly face the magnetic poles of the rod-shaped parts 411a and 411b.

Furthermore, the mounting attitude of the mirror section 12 is adjusted based on the state in which the magnet 32 is in the neutral position. Note that the rotation angle position holding section 48 may be made of a magnetic material that generates a magnetic attraction force between it and the magnet 32.

<Bottom cover 50 and top cover 60>
The bottom cover 50 and top cover 60 shown in FIGS. 1, 2, 4 to 6, and 11 to 14 are preferably made of an electrically conductive material that is non-magnetic and has high electrical conductivity, and functions as an electromagnetic shield. do.

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

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

The bottom cover 50 and the top cover 60 are made of a non-magnetic, electrically conductive, and high thermal conductive material such as an aluminum alloy. Aluminum alloys have a high degree of freedom in design and can easily be provided with desired rigidity. Therefore, if the bottom cover 50 and the top cover 60 are made of aluminum alloy, it is suitable for the top cover 60 to function as a support for supporting the rotating shaft 13.

FIG. 11 shows a front perspective view of the bottom cover. The bottom cover 50 is attached to overlap the outer surface of the wall portion 211. The bottom cover 50 is formed into 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 52, and an opening 53 through which the rotating shaft 13 is inserted is formed in the center of the cover body 52. The opening 53 is arranged at a position facing the bearing 22 , and the inner diameter of the opening 53 is larger than the outer diameter of the magnet 32 . In the bottom cover 50, the rotating shaft 13 with the magnet 32 attached thereto can be inserted into the opening 53, and the magnet 32 can be inserted and placed in the core assembly 40.

The rotating shaft 13 is inserted into the opening 53, and a preload spring 35 is disposed externally on the rotating shaft 13 (see FIG. 2).

The cover body 52 of the bottom cover 50 is provided with a through hole 54, a through hole 55 for fixing to the base portion 21, a positioning hole 56, a position adjustment hole 57, and a core holding protrusion 58. A fastening member 86 that integrates the bottom cover 50 with the core assembly 40 and the top cover 60 as a drive unit 4 is inserted into the through hole 54 . The through hole 55 is formed in a mounting portion 522 that is attached to the wall portion 211 . The attachment portions 522 constitute left and right sides of the cover body 52 that are spaced apart in a direction perpendicular to the axial direction, and include four corners of the cover body 52. Through holes 55 are formed at each of these corners.

The opening 53, the through holes 54 and 55, the positioning hole 56, and the position adjustment hole 57 are formed parallel to the axial direction of the rotating shaft 13. By inserting the fastening members 81 and 86 into the through holes 54 and 55, assembly to the base portion 21 or the drive unit 4, and ultimately the rotary reciprocating drive actuator 1 can be performed in one direction in the axial direction. can.

As shown in FIGS. 7 and 11, the through hole 54 has a recessed counterbore 541 formed on the back surface of the cover body 52, and the counterbore 541 accommodates the head of a fastening member 86 such as a screw.

The core holding protrusion 58 is provided to protrude in the axial direction from a position sandwiching the opening 53 in the cover body 52, and is fitted into and positioned with the core assembly 40 when combined with the core assembly 40. (See Figures 3 and 4)

The core holding protrusion 58 is inserted between the rod-shaped parts 411a, 411b and both side parts 413a, 413b, and prevents leakage of magnetic flux flowing between them.

Further, as shown in FIG. 6, a positioning protrusion 59 is provided on the back surface of the bottom cover 50 in a protruding manner. The positioning protrusion 59 engages with a recess 218 (see FIGS. 2 and 4) formed in the wall 211 when the bottom cover 50 abuts the base 21 with their centers aligned. .

The positioning protrusion 59 is, for example, an annular protrusion. On the other hand, the recess 218 of the wall portion 211 is an annular groove formed in the base portion 21 so as to surround the insertion hole 211a, as shown in FIGS. 2 and 4. The positioning protrusion 59 engages with the recess 218 of the annular groove, and both the wall portion 212 and the drive unit 4 are positioned.

The top cover 60 and the bottom cover 50 sandwich the core assembly 40 from both sides in the axial direction, and are integrally fixed by a fastening member 86 to form the drive unit 4. As shown in FIGS. 2 and 4, the top cover 60 of this embodiment functions as a sensor accommodating portion 65 that accommodates an optical sensor 76 that detects the rotation angle of the movable body 10, that is, the rotating shaft 13.

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

The top cover main body 62 is a plate-shaped body that has a square shape when viewed from the axial direction and has a concave portion 621 that opens toward the core assembly 40 side. The top cover main body 62 is a square plate-shaped body, and the peripheral wall portion 64 is formed in the shape of a rectangular frame rising from the outer peripheral portion of the top cover main body 62.

A through hole 66 is provided in the top cover main body 62 of the top cover 60. The through hole 66 is arranged in the top cover main body 62 so as to have the same axis as the opening 53 of the bottom cover 50 and the bearings 22 and 23 of the base portion 21 . A bush 39 into which the rotating shaft 13 is inserted is fitted into the through hole 66 from the back side (one end 131 side). Thereby, the bush 39 is attached to the top cover main body 62 in a state where the direction of movement is restricted. Note that the bush 39 and the rotating shaft 13 may be arranged so as to slide relative to each other, or may be arranged with a gap between them.

The bush 39 supports the other end 132 side of the rotating shaft 13. The bush 39 is supported by the top cover 60 on the other end 132 side to prevent the shaft from wobbling due to the impact, such as when the rotating shaft 13 receives an impact. The bush 39 is attached to the top cover 60 such that the other end fits into the through hole 66 and one end is located within the recess 621.

In addition to the through-hole 66, the top cover main body 62 is provided with a bobbin-engaging hole 67 that penetrates in the axial direction and engages with the bobbins 46 and 47.

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

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

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

<Angle sensor section 70>
FIG. 12 is an external perspective view of the angle sensor section in the rotary reciprocating drive actuator 1, FIG. 13 is an exploded perspective view of the front side of the angle sensor section, and FIG. 14 is an exploded perspective view of the back side of the angle sensor section. be.

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

The angle sensor section 70 detects the rotation angle of the movable body 10 (the same applies to the mirror section 12) including the magnet 32 and the rotation shaft 13. The rotary reciprocating drive actuator 1 controls the rotational angular position and rotational speed of the movable body during driving, specifically, the mirror unit 12 which is a movable object, through the control unit based on the detection result of the angle sensor unit 70. can be controlled.

The angle sensor section 70 may be a magnetic sensor or an optical sensor. In this embodiment, the angle sensor section 70 includes a sensor component, a sensor substrate 72, and a substrate holding section 73.

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

The board holding section 73 holds the sensor board 72 to be attached, and forms an arrangement space (sensor arrangement section 701) in which sensor components are arranged, by the sensor board 72 and the wall section 212.

The substrate holding part 73 is, for example, a plate-shaped body having an opening 732 in the center, and is fixed to the outer surface 21a of the wall part 212, and constitutes a concave sensor arrangement part 701 into which the rotating shaft 13 is inserted. A sensor board 72 is attached to the board holding part 73 so as to cover the internal space. Thereby, the board holding section 73 can accommodate the sensor components while preventing contamination.

Although the substrate holding portion 73 is formed in a frame shape, the substrate holding portion 73 is not limited to this, and may be formed in a concave shape as long as it forms a space through which the rotating shaft 13 can be inserted and in which sensor components can be placed. good. The board holding part 73 is fixed to the wall part 212 by inserting the fastening member 85 that passes through the fastening hole 702 into the fastening hole 215 of the wall part 212 and fitting (for example, screwing). .

The encoder disk 74 is fixed to the one end 131 side of the rotating shaft 13 via a mounting portion (encoder hub) 742 in the center, and is also fixed to the one end 131 side of the rotating shaft 13 and inside the opening 732 of the board holding portion 73 (inside the sensor placement portion 701). It is located in

The encoder disk 74 is for detecting the rotation speed of the rotating shaft 13 and rotates together with the magnet 32 and the mirror section 12. The rotational position of the encoder disk 74 around the axis is the same as the rotational position of the rotating shaft 13.

Optical sensor 76 is placed opposite encoder disk 74 . The optical sensor 76 emits light to the encoder disk 74 and detects the rotational position (angle) of the encoder disk based on the reflected light. Thereby, the rotational positions of the magnet 32 and the mirror section 12 can be detected accurately with high resolution.

The optical sensor 76 is mounted on the back surface of the sensor board 72. By attaching the sensor substrate 72 to the substrate holding part 73, the optical sensor 76 is arranged in the sensor arrangement part 701 so as to face the encoder disk 74 in the axial direction. The optical sensor 76 is arranged in the optical sensor arrangement section 701 so as to be able to detect the rotational speed and rotational position of the encoder disk 74.

The sensor substrate 72 is arranged so as to close the opening 732 of the substrate holding section 73 from the one end 131 side, and constitutes a closed sensor arrangement section 701.

The sensor board 72 has an opening 724 in the center, into which a mounting shaft (encoder hub) 742 to which the encoder disk 74 is attached and the rotating shaft 13 are inserted. is supportable. The sensor board 72 is fixed to the substrate holding part 73 by the fastening member 84 being fixed to the fastening hole 703 of the substrate holding part 73 via the fastening hole 723 . As a result, the sensor substrate 72 is fixed to the substrate holding part 73 fixed to the wall part 212, so that the sensor board 72 is fixed to the wall part 212 via the board holding part 73.

Note that the wall portion 212, the substrate holding portion 73, and the sensor substrate 72 have positioning holes 205, 705, and 725, and position adjustment holes 207, which are used to position and fix the angle sensor portion 70 to the wall portion 212 at a suitable position. 707 and 727 are provided.

The positioning holes 205, 705, and 725 are arranged on the same axis parallel to the rotating shaft 13 and have the same diameter (including approximately the same diameter). The position adjustment holes 207, 707, and 727 are arranged in the same shape on the same axis parallel to the rotating shaft 13, and have a shape that creates a gap when a rod-shaped adjustment member (not shown) is inserted therethrough.

With these configurations, adjustment members (not shown) are inserted into the position adjustment holes 207 , 707 , and 727 before the wall portion 212 , substrate holding portion 73 , and sensor substrate 72 are fastened with the fastening member 84 . In this state, while moving the wall portion 212, substrate holding portion 73, and sensor substrate 72 and adjusting them to suitable positions, a rod-shaped positioning material is inserted through each of the positioning holes 205, 705, and 725. be able to. Thereby, the substrate holding section 73 and the sensor substrate 72 are positioned at suitable positions with respect to the wall section 212 with the rotation axis 13 as the center. In this state, the substrate holding section 73 and the sensor substrate 72 can be fixed to the wall section 212 at suitable positions.

The sensor substrate 72 is fixed to the substrate holder 73 via a fastening member 84 inserted through the fastening hole 703 so that the optical sensor 76 to be mounted faces the encoder disk 74 within the opening 732.

By simply attaching the sensor substrate 72 to the substrate holding section 73, it is possible to prevent unnecessary objects such as dust from entering the sensing portion of the angle sensor section 70, including the optical sensor 76 and the encoder disk 74.

Next, the operation of the rotary reciprocating drive actuator 1 will be explained using FIGS. 3 and 15. FIG. 15 is a diagram for explaining the operation of the magnetic circuit of the rotary reciprocating drive actuator 1.

The magnetic poles 410a and 410b of the two rod-shaped parts 411a and 411b of the core body 400 of the core assembly 40 are arranged so as to sandwich the magnet 32 with an air gap G between them. When the coils 44 and 45 are not energized, as shown in FIG. 3, the magnet 32 is held at the neutral position by the magnetic attraction between it and the rotation angle position holding section 48.

At this neutral position, one of the south pole 32a and the north pole 32b (the south pole 32a in FIG. 20) of the magnet 32 is attracted to the rotation angle position holding part 48 (see magnetic spring torque FM in FIG. 20). At this time, the magnetic pole switching parts 32c and 32d face the center positions of the magnetic poles 410a and 410b of the core body 400. Furthermore, the commutative pole portion 414 attracts the other of the S pole 32a and the N pole 32b of the magnet 32 (the N pole 32b in FIG. 20). Thereby, the magnet 32 is more effectively moved to the neutral position.

When the coils 44 and 45 are energized, the core body 400 is excited, and the magnetic poles 410a and 410b have polarities depending on the direction of energization. For example, as shown in FIG. 20, when the coils 44 and 45 are energized, magnetic flux is generated inside the core body 400, and the magnetic pole 410a becomes the north pole and the magnetic pole 410b becomes the south pole.

As a result, the magnetic pole 410a magnetized to the north pole attracts the south pole 32a of the magnet 32, and the magnetic pole 410b 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 rotating shaft 13, and the magnet 32 rotates in the F direction. Along with this, the rotating shaft 13 also rotates in the F direction, and the mirror portion 12 fixed to the rotating shaft 13 also rotates in the F direction.

Next, when the coils 44 and 45 are energized in the opposite direction, the flow of magnetic flux generated inside the core body 400 is in the opposite direction to that shown in FIG. 410b becomes the north pole. The magnetic pole 410a magnetized to the south pole attracts the north pole 32b of the magnet 32, and the magnetic pole 410b magnetized to the north pole attracts the south pole 32a of the magnet 32. Then, a torque -F in the opposite direction to the F direction is generated around the rotating shaft 13 in the magnet 32, and the magnet 32 rotates in the -F direction. Along with this, the rotating shaft 13 also rotates, and the mirror portion 12 fixed to the rotating shaft 13 also rotates in the opposite direction as shown in FIG. 15.
The rotary reciprocating drive actuator 1 rotates and reciprocates the mirror portion 12 by repeating the above operation.

In reality, the rotary reciprocating drive actuator 1 is driven by alternating current waves input to the coils 44 and 45 from a power supply section (e.g., corresponding to the drive signal supply section 103 in FIG. 21). In other words, the current direction of the coils 44 and 45 is periodically switched. When the energization direction is switched, the magnetic attraction force between the rotational angle position holding part 48 and the magnet 32, that is, the restoring force of the magnetic spring (magnetic spring torque FM shown in FIG. 20 and "-FM" which is the torque in the opposite direction) As a result, the magnet 32 is urged to return to the neutral position. As a result, torque in the F direction and torque in the opposite direction to the F direction (-F direction) are alternately applied to the movable body 10 around the axis. As a result, the movable body 10 is driven to rotate and reciprocate.

The driving principle of the rotary reciprocating drive actuator 1 will be briefly explained below. In the rotary reciprocating drive actuator 1 of this embodiment, the moment of inertia of the movable body (movable body 10) is J [kg·m ² ], and the moment of inertia of the movable body (movable body 10) is J [kg·m 2 ], and the moment of inertia of the movable body (movable body 10) is When the spring constant in the torsional direction is K _sp [N m/rad], the movable body has a resonance frequency F _r [Hz] calculated by equation (1) with respect to the fixed body (fixed body 20). Vibrates (reciprocating rotation).

Since the movable body constitutes a mass portion in the spring-mass vibration model, when an AC wave having a frequency equal to the resonant frequency _Fr of the movable body is input to the coils 44 and 45, the movable body enters a resonant state. That is, by inputting an alternating current wave having a frequency substantially equal to the resonant frequency _Fr of the movable body from the power supply section to the coils 44 and 45, the movable body can be efficiently vibrated.

An equation of motion and a circuit equation 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 equation (2) and the circuit equation shown in equation (3).

That is, the moment of inertia J [kg・m ² ] of the movable body in the rotary reciprocating drive actuator 1, the rotation angle θ(t) [rad], the torque constant K _t [N・m/A], and the 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. are within the range that satisfies equation (2). Can be changed as appropriate. In addition, the voltage e(t) [V], the resistance R [Ω], the inductance L [H], and the back electromotive force constant K _e [V/(rad/s)] are set as appropriate within the range that satisfies equation (3). Can be changed.

In this way, the rotary reciprocating drive actuator 1 has an efficient large current when the coil is energized by an alternating current wave corresponding to the resonance frequency _Fr determined by the moment of inertia J of the movable body and the spring constant _Ksp of the magnetic spring. Vibration output can be obtained.

<Modification 1>
FIG. 16 is an external perspective view of Modification 1 of the rotary reciprocating drive actuator, and FIG. 17 is a longitudinal sectional view passing through the axis of Modification 1 of the rotary reciprocating drive actuator. Further, FIG. 18 is an exploded perspective view of Modification 1 of the rotary reciprocating drive actuator, and FIG. 19 is a perspective view of a wall portion on one end side of Modification 1 of the rotary reciprocating drive actuator. Moreover, FIG. 20 is an exploded perspective view of the front surface side of the sensor section disposed on the wall portion on the same end side.

The rotary reciprocating drive actuator 1A of Modification Example 1 has a substrate holding part in the angle sensor part 70A attached to the wall part 212A side on the one end side of the base part 21A, compared to the rotary reciprocating drive actuator 1 configured in substantially the same way. The only difference is that the structure is provided on the wall portion 212A, and the other structures are the same. Therefore, the same names having the same functions will be given the same reference numerals, and the explanation will be omitted, and only the different points will be explained.

In the rotary reciprocating drive actuator 1A shown in FIGS. 16 to 20, a movable body 10A is attached to a base portion 21A to constitute a main body unit 2A. Note that the main unit 2A is configured by mounting the movable body 10 on the base portion 21A. Furthermore, the base portion 21A and the drive unit 4 constitute a fixed body 20A that supports the movable body 10 in a reciprocating manner. The rotary reciprocating drive actuator 1A has an angle sensor section 70A on a wall section 212A that is one end of the main body unit 2A, and a drive unit 4 on a wall section 211A disposed on the other end side of the main body unit 2A. have. Further, the angle sensor section 70A includes an encoder disk 74, an optical sensor 76, and a sensor substrate 72.

The rotary reciprocating drive actuator 1A does not have a substrate holding part, as compared to the rotary reciprocating drive actuator 1, and the function of the substrate holding part is provided integrally with the wall part 212A. The wall portions 212A, together with the wall portions 211A, stand perpendicularly from both ends of a flat bottom portion 213A configured similarly to the bottom portion 213, and face each other at a distance. A concave sensor placement portion 230 that opens toward the other end portion 131 is provided on the wall portion 212A of the base portion 21A.

Specifically, the wall portion 212A on the other end side of the base portion 21A, which is configured similarly to the base portion 21, has a frame-shaped peripheral wall portion 240 having the same function as the substrate holding portion 73. On the outer surface 21a of the wall portion 212A, a concave sensor placement portion 230 is provided at the center surrounded by the frame-shaped peripheral wall portion 240. One end portion 131 of the rotating shaft 13, which is inserted through the wall portion 212A, protrudes from the sensor placement portion 230.

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

The sensor board 72 is attached to the outer surface 21a of the wall portion 212A via the attachment holes 723 and 215 by the attachment member 84 so as to cover the sensor arrangement portion 230. According to the configuration of the rotary reciprocating drive actuator 1A, it has the same effect as the embodiment, and since there is no need to use a separate member as the substrate holding part, the number of parts can be reduced and the manufacturing time can be shortened. When attaching the sensor board 72 to the wall 212A, the positioning holes 205, 725 and the position adjustment holes 207, 727 provided in the wall 212, the sensor board 72 allow the sensor board 72 to be rotated to the wall 212A. It can be positioned at a suitable position centering on the axis 13.

<Scanner system 100>
FIG. 21 is a block diagram showing the configuration of main parts of a scanner system 100 using the rotary reciprocating drive actuator 1.

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

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

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

The drive signal supply unit 103 supplies the coils 44 and 45 of the rotary reciprocating drive actuator 1 with a drive signal such that the angular position of the rotating shaft 13 (mirror 121) becomes a desired angular position based on the position control signal. . Thereby, the scanner system 100 can emit scanning light from the rotary reciprocating drive actuator 1 to a predetermined scanning area.

<Summary>
As explained above, the rotary reciprocating drive actuator 1 according to the present embodiment includes the rotating shaft (shaft portion) 13 to which the mirror portion (movable object) is connected, and the magnet 32 fixed to the rotating shaft 13. A movable body 10 is provided. Note that the magnet 32 is a ring-shaped magnet in which S poles 32a and N poles 32b are alternately arranged in the circumferential direction on the outer peripheral surface. In addition, the rotary reciprocating drive actuator 1 has a fixed body 20 with a core assembly 40.

The rotating shaft 13 is rotatably supported by a pair of wall portions 211 and 212 of the base portion 21. The core assembly 40 is attached to the other wall 211 of the pair of walls 211 and 212, and one wall 212 of the pair of walls 211 and 212 has a rotation angle of the rotation shaft 13. An angle sensor section 70 for sensing is arranged. In the angle sensor section 70, a sensor (optical sensor) 76 is mounted, and a sensor board 72 is attached to one wall 212 from the one end 131 side with the sensor facing the one wall.

In this way, since the angle sensor parts (encoder disk, etc.) are placed near the bearing 23 at a position apart from the core assembly 40, they are free from the effects of electromagnetic noise and heat generation from the core assembly and mechanical damage during driving. Therefore, angle detection can be suitably performed without any concern about the influence of vibration, and without the influence of shaft wobbling of the rotating shaft 13. Therefore, the rotation of the shaft connected to the movable object can be detected accurately, and the movable object can be driven more suitably with high amplitude.

The sensor substrate 72 covers the detection section (encoder disk) of the sensor component outside the sensor arrangement sections 701 and 230. Thereby, the sensor substrate 72 can prevent contamination into the sensor placement parts 701 and 230. In this way, it is possible to prevent foreign matter from entering the sensor arrangement parts 701 and 230, accurately detect the rotation angle, and drive the movable object in a suitable manner.

Furthermore, the angle sensor section 70 is constructed by arranging an encoder disk 74, which is a detected section, at one end 131 of the rotation shaft 13, and facing the optical sensor 76 implemented on the sensor substrate 76 in the axial direction of the rotation shaft 13. It is configured. This configuration provides a layout in which the dimensions of the configuration in which the angle sensor section 70 is disposed is minimized, making it possible to downsize the rotary reciprocating drive actuator 1 itself and stably holding the optical sensor 76.

Further, when maintaining the angle sensor section 70, simply removing the fastening member 84 exposes the sensor component, which is an expensive component, to the outside in the event of a malfunction, making it possible to easily recover or replace it.

Further, when the sensor section is an optical sensor, it is possible to prevent light from interfering with the sensor arrangement section (which may be a housing section for accommodating the sensor) 701 and 230 without using a separate light shielding member.

When fixing the drive unit 4 to the main body unit 2, if the rotating shaft 13 is used as a reference, it is desirable to fix the drive unit 4 at a position where the dimensions can be defined based on the reference. In addition, when fixing a rotary reciprocating drive actuator to the product's casing with the shaft vertically erected, it is also possible to position and fix the rotary reciprocating drive actuator from a direction parallel to the axis, assembling the rotary reciprocating drive actuator, and fixing the rotary reciprocating drive actuator's casing. It can be attached to. As a result, even when assembling in a direction different from the axial direction, highly accurate positioning and fixing can be performed with less additional dimension.

Further, a gap (clearance) narrower than the air gap between the magnet 32 and the core assembly 40 may be provided between the bush 39 and the outer periphery of the rotating shaft 13. In this case, there is no sliding movement between the bush 39 and the rotating shaft 13, and impact resistance can be ensured. Further, if the bush 39 and the rotary shaft 13 are configured to slide, it is possible to reliably receive an impact, prevent the impact from being applied to the sensor section, dampen unnecessary vibrations of the movable body, and reduce noise.

Further, the movable object is the mirror section 12 (particularly the mirror 121) that reflects the scanning light. Thereby, the rotary reciprocating drive actuator 1 can be used for a scanner that performs optical scanning.

Further, the ring-shaped magnet 32 of the rotary reciprocating drive actuator 1, 1A of this embodiment has the magnetic pole switching portions 32c, 32d formed in a U-shape formed on the end surface 322 on one side, as shown in FIG. Although it is configured with a groove, it does not need to be configured with a U-shaped groove. The magnetic pole switching section may be configured in any manner as long as it indicates the position where the magnetic pole changes in the magnet 32. Modifications of the magnet 32 will be described with reference to FIGS. 22 to 26.

22 to 26 show modifications 1 to 4 of the magnets in the rotary reciprocating drive actuators 1 and 1A. 23 to 25 respectively show a front view and a right side view of a magnet as a modified example, and FIG. 26 shows a core assembly of a rotary reciprocating drive actuator having a modified example 4. 2, which corresponds to an end view of the rotary reciprocating drive actuator having the magnet 32 taken along line AA in FIG. 2.

The magnets 320, 320A, and 320B shown in FIGS. 23 to 25 each have a ring shape, and each has an opening 321 in the center through which the rotating shaft 13 is inserted.

The magnet 320 shown in FIG. 23 integrally has protruding magnetic pole switching portions 32e and 32f on the diameter portion of one end surface 322. The magnetic pole switching parts 32e and 32f are protrusions (projections) formed on the same straight line on the end face 322 with the opening 321 in between, and their tip surfaces may be rounded or flat. It may be a surface.

The magnetic pole switching parts 32e and 32f allow the magnet 320 to determine the switching position of the magnetic pole in the magnet 320 based on its shape.

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

The magnetic pole switching parts 32g and 32h allow the magnet 320A to determine the switching position of the magnetic pole in the magnet 320A based on its shape.

Here, in addition to the magnet 32, the magnets 320 and 320A are desirably arranged with a well-balanced assembly accuracy in accordance with the angle reference of the mirror section 12 and the angle reference of the angle sensor 76, which are movable objects. If a deviation occurs in each angular reference, there is a problem in that the characteristics change depending on the rotation angle of the rotating shaft 13, which causes performance variations.

On the other hand, in the present embodiment, the magnetic pole switching parts 32c to 32h of the magnets 32, 320, 320A are formed in a U-shape, a projecting shape, a V-shape, etc., and the magnets 32, 320, 320A are It has an uneven shape in the magnetization direction.

Therefore, using a positioning jig having pins corresponding to U-shape, protrusion-shape, V-shape, etc., other parts etc. are assembled using these magnetic pole switching parts 32c, 32d, 32e, 32f, 32g, 32h as a reference. or assemble a rotary reciprocating drive actuator.

That is, the positional relationship of each component fixed to the rotating shaft 13 during assembly or maintenance of the rotary reciprocating drive actuator 1 is determined based on the uneven portions (magnetic pole switching portions 32c, 32d, 32e, 32f, 32g, 32h). can be adjusted. In the rotary reciprocating drive actuator 1, the angular accuracy of the mirror section 12, the angular reference of the angle sensor section 70, and the magnetic pole reference of the magnet 32 can be easily aligned, and highly accurate assembly can be easily realized.

In addition, if the magnet 32 is configured such that the unevenness is provided in the magnetization direction, the influence on the magnetic poles 410a and 410b facing each other on the outer peripheral surface and the rotational angle position holding part (magnetic spring) 48 will be small, and the influence on the torque will be reduced. Moreover, the characteristics of the magnetic attraction force of the rotation angle position holding section 48 do not vary.

For example, a magnet 320B shown in FIG. 25 has a flat surface 328 with a portion of the outer peripheral surface 326 cut out. The flat surface 328 is provided as a part of the outer peripheral surface of one of the different magnetic poles in the magnet 320B.

When the core assembly 40B having the magnet 320B is provided in the rotary reciprocating drive actuator 1, the magnetic pole 32a facing the rotation angle position holding part 48 and the magnetic pole 32b on the opposite side as shown in FIG. 26 have a flat surface 328. Placed. This flat surface 328 faces the curved surface of the commutating pole section 414. Specifically, when the magnet 320B is at the reference position, the center of the length of the flat surface 328 in the circumferential direction (horizontal direction) and the center of the circumferential direction (horizontal direction) of the commutative pole part 414 are aligned with the opening. It is arranged so as to be located on a line passing through the center of the portion 321 (or the rotating shaft 13) and perpendicular to the flat surface 328.

In the magnet 320B, for example, if the flat surface 328 is arranged opposite to the rotational angle position holding part 48 or the core (magnetic poles 410a, 410b) side, the flow of magnetic flux generated will be unbalanced because there is only a flat part in the magnet 320B. This may affect the magnetic circuit characteristics and degrade performance.

On the other hand, in the present embodiment, the flat surface 328 of the magnet 320B is arranged on the opposite side of the rotational angle position holding part 48 with the rotation shaft 13 in between when the magnet 320B is in a non-energized state, for example, at the reference position. It is composed of Thereby, the flat surface 328 can generate a magnetic attraction force with the commutating pole part 414 while avoiding any influence on the rotational angle position holding part 48, that is, avoiding unbalanced torque generation. Note that it is also possible to use the flat surface 328 to assemble other parts or the like or to assemble a rotary reciprocating drive actuator using the magnet 320B as a reference.

As above, the invention made by the present inventor has been specifically explained based on the embodiments, but the present invention is not limited to the above embodiments, and can be modified without departing from the gist thereof.

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

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

Further, the configuration of the drive unit 4 is not limited to that described in the embodiment. For example, the core has a magnetic pole part that is excited and polarized when the coil is energized, and when the rotating shaft is attached to a fixed body, the magnetic pole part and the outer peripheral surface of the magnet face each other through an air gap. It is fine as long as it is. Further, the coil may have a configuration that appropriately generates magnetic flux from one of the magnetic pole portions of the core toward the other when energized.

Further, although the rotation angle position holding section 48 provided on the fixed body 20 is attached to the second core 42, the present invention is not limited to this, and may be provided on other components of the fixed body 20. Further, for example, the rotation angle position holding section 48 may be provided so as to protrude from the surface of the cover body 52 or the back surface of the top cover body 62 so as to be disposed at the same position as the position where it is attached to the second core 42. good. Further, in these cases, the rotation angle position holding section 48 may be housed within the drive unit 4.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

The present invention is suitable for use in, for example, LiDAR devices and scanner systems.

1, 1A Rotating and reciprocating drive actuator 2 Main unit 4 Drive unit 10, 10A Movable body 12 Mirror part 13 Rotating shaft 14 Stop part 15, 15A Stopper part 20 Fixed body 21, 21A Base part 21a Outer surface 22, 23 Bearing 30 Drive part 32 , 320, 320A, 320B Magnets 32a, 32b, 410a, 410b Magnetic poles 32c, 32d, 32e, 32f, 32g, 32h Magnetic pole switching section 35 Preload spring 37 Annular receiving section 39 Bush 40 Core assembly 41 First core 42 Second Core (bridge)
43 Third core 44, 45 Coil 46, 47 Bobbin 48 Rotation angle position holding part 49 Coil body 50 Bottom cover 52 Cover body 53, 321, 732 Opening 54, 55, 66 Through hole 56, 205, 705, 725 Positioning hole 57, 207, 707, 727 Position adjustment hole 58 Positioning protrusion 60 Top cover 62 Top cover main body 64 Peripheral wall portion 67 Bobbin engagement hole 70, 70A Angle sensor portion 72 Sensor board 73 Board holding portion 74 Encoder disk (detected portion)
76 Optical sensor (sensor)
81, 84, 85, 86 Fixing member 100 Laser system 101 Laser emitting unit 102 Laser control unit 103 Drive signal supply unit 104 Position control signal calculation unit 121 Mirror 122 Mirror holder 122a, 211a, 212a Insertion hole 131 One end 132 Other end Part 133 Fitting groove 203, 215, 402, 702, 703, 723 Fastening hole 211, 211A, 212, 212A Wall part 211a, 211Aa, 212a Insertion hole 213, 213A Bottom part 218 Recessed part 222, 232 Bearing body 224, 234 Flange 230, 701 Sensor arrangement section 322 End surface 326 Outer peripheral surface
328 Flat surface 400 Core body 411, 411a, 411b Rod-shaped part 412 Connection side part 413, 413a, 413b Side part 414 Compensating pole part 492 Bobbin part 494 Terminal support part 496 Terminal 522 Mounting part 541 Counterbore part 621 Concave part 742 Mounting shaft Part 4964 Other side part 4962 One side part

Claims (5)

A movable body that has a shaft portion to which a movable object is connected at one end side and a magnet fixed to the shaft portion at the other end side, and is supported for reciprocating rotation around the shaft;
a base portion rotatably supporting the shaft portion via a bearing on the one end side and having a pair of walls arranged to sandwich the movable object;
a core body having a plurality of magnetic poles facing the outer periphery of the magnet so as to sandwich the magnet; and a magnetic flux that is wound around the core body and interacts with the magnet, which is generated by energization to cause the movable body to reciprocate. The coil body has a magnet position holding part that generates a magnetic attraction force between the coil body and the magnet to define a reference position of the reciprocating rotation, and is attached to the other wall of the pair of walls. a core assembly;
A sensor is mounted on one of the pair of walls and detects the rotation angle of the shaft, and the sensor is mounted on one of the two walls from the one end side with the sensor facing the one wall side. A sensor board placed on the wall,
Equipped with
Rotary reciprocating actuator. The number of poles of the plurality of magnetic poles is two poles,
The rotary reciprocating drive actuator according to claim 1. the sensor is an optical sensor;
The rotary reciprocating drive actuator according to claim 1. a substrate holder on the one end side of the one wall that surrounds the sensor and attaches and holds the sensor substrate;
has,
The rotary reciprocating drive actuator according to claim 1. the movable object is a mirror that reflects the scanning light;
The rotary reciprocating drive actuator according to claim 1.

Images