Rotary actuator

Abstract

To provide a rotary actuator capable of improving maintainability.SOLUTION: A rotary actuator 10 includes: a recessed groove 53 provided in a second ring surface part 50b of the base member 20 as a part facing the rotary member 30, and extending in a rotational direction of the rotary member 30; a spherical body 54 provided on a rear surface part as an opposed part to the base member 20 of the rotary member 30 and moving inside the recessed groove 53 according to the rotation of the rotary member 30 to the base member 20; and first and second detection switches 27, 28 provided on both sides in a longitudinal direction of the recessed groove 53 and operated by the spherical body 54. An angle position of a stepping motor can be corrected to a normal position by periodically rotating the rotary member 30 with respect to the base member 20 by a control unit and pressing the first detection switch 27 or the second detection switch 28 by the spherical body 54. Therefore, it is possible to realize the rotary actuator 10 with improved maintainability.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a rotary actuator that rotates an object to be driven. [Background technology]

[0002] For example, Patent Document 1 describes a network device equipped with a driver that rotates a signal receiving antenna. The driver has a drive motor and a reducer consisting of multiple gears, and is housed inside a base. A bracket that supports the signal receiving antenna is rotatably connected to the base. The network device further includes a main controller. The main controller controls the drive motor to rotate the signal receiving antenna (bracket) so that it faces a direction with a strong signal strength. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2023-508219 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, a position detector consisting of a Hall sensor and a magnetic member is used to detect the rotation angle of the bracket relative to the base. Therefore, if the main controller fails to receive a pulse signal from the Hall sensor for some reason and the count value of the pulse signal is incorrect, an error will occur in the rotation angle of the bracket relative to the base during rotation control. In this case, maintenance is required to match the count value of the pulse signal with the rotation angle of the bracket relative to the base.

[0005] An object of the present invention is to provide a rotary actuator that can improve maintainability. [Means for solving the problem]

[0006] In one aspect of the present invention, a rotary actuator has a base member, a rotating member supported on the base member for free rotation, and an electric motor for rotating the rotating member, and is equipped with a groove provided on the base member facing the rotating member and extending in the rotational direction of the rotating member, a piece member provided on the rotating member facing the base member and moving within the groove as the rotating member rotates relative to the base member, and a rotation detection switch provided on both longitudinal sides of the groove and operated by the piece member. Effect of the Invention

[0007] According to the present invention, a rotary actuator capable of improving maintainability can be realized. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a rotation actuator according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the rotary actuator of FIG. 1. [Diagram 3] 2 is a plan view of the rotary actuator of FIG. 1, viewed from the rotary member (broken line) side. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Diagram 5] FIG. 5 is an enlarged view of a portion B circled by a dashed line in FIG. [Figure 6] FIG. 4 is an exploded perspective view showing a ring-shaped member and a switch board. [Figure 7] FIG. 2 is an exploded perspective view showing a base member and a ring-shaped member. [Figure 8] FIG. 4 is a perspective view of a rotating member as viewed from the base member side. [Figure 9] 1A to 1C are partially enlarged views for explaining the movement (for each angle) of a spherical body. [Figure 10] FIG. 11 is an exploded perspective view showing a rotation actuator (rotary member omitted) of a second embodiment. [Figure 11] 11 is an enlarged plan view (rotary members omitted) of a portion corresponding to the first switch board and the second switch board of the rotary actuator in FIG. 10. FIG. [Figure 12] 11 is an enlarged perspective view illustrating a method for adjusting the positions of a first switch board and a second switch board relative to a ring-shaped member. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] <Embodiment 1> Figure 1 is an oblique view showing a rotary actuator of embodiment 1, Figure 2 is an exploded oblique view of the rotary actuator of Figure 1, Figure 3 is a plan view of the rotary actuator of Figure 1 seen from the rotating member (dashed line) side, Figure 4 is a cross-sectional view along line AA of Figure 3, Figure 5 is an enlarged view of the dashed circle B in Figure 4, Figure 6 is an exploded oblique view showing a ring-shaped member and a switch board, Figure 7 is an exploded oblique view showing a base member and a ring-shaped member, Figure 8 is an oblique view of the rotating member seen from the base member side, and Figure 9 is a partially enlarged view explaining the operation of the spherical body (for each angle).

[0011] <Outline of Rotary Actuator> 1 and 2, the entire rotary actuator 10 is formed in a substantially disk shape. The rotary actuator 10 is used, for example, as a drive source for rotating an antenna (not shown) capable of receiving millimeter waves in a direction of strong signal strength. Here, millimeter waves are radio waves suitable for high-speed, large-capacity communication, and refer to radio waves with a wavelength of 1 to 10 millimeters and a frequency of 30 to 300 gigahertz.

[0012] The rotary actuator 10 includes a base member 20 fixed to a floor surface, a base, or the like (not shown), and a rotary member 30 rotatably supported by the base member 20. A stepping motor 40 for rotating the rotary member 30 is fixed to one axial side (the lower side in the figure) of the base member 20. A connector connection portion 41 of the stepping motor 40 is electrically connected to the control unit CU.

[0013] The stepping motor 40 corresponds to the electric motor in the present invention.

[0014] <About stepping motors> 2, the stepping motor 40 is formed in a substantially cylindrical shape. The stepping motor 40 includes a motor main body 42 and a planetary gear reduction unit 43, with the motor main body 42 disposed on one axial side (lower side in the figure) of the stepping motor 40 and the planetary gear reduction unit 43 disposed on the other axial side (upper side in the figure) of the stepping motor 40. The planetary gear reduction unit 43 has an output shaft 44, to which a pinion gear 45 is fixed.

[0015] As a result, the pinion gear 45 is rotated with high torque as the motor body 42 is rotated. The output shaft 44 to which the pinion gear 45 is fixed corresponds to the rotating shaft in the present invention. Here, the stepping motor 40 is a motor that can precisely control the rotation angle and rotation speed of the output shaft 44 by a pulse signal (rectangular wave signal) from the control unit CU.

[0016] Further, a pair of mounting portions 43a are integrally provided on the planetary gear reduction portion 43. These mounting portions 43a are fixed to the first surface portion 21a (see FIG. 4) of the base member 20 by a pair of motor fixing screws (not shown). In other words, the stepping motor 40 is fixed to the side of the base member 20 opposite the rotating member 30 side by the pair of motor fixing screws so as not to rattle.

[0017] <Base material> As shown in Figs. 1 to 4 and 7, the base member 20 is formed in a substantially annular shape from a resin material such as plastic. The base member 20 includes an annular main body 21 and a plurality of fixed legs 22. The annular main body 21 has a first surface 21a and a second surface 21b. Specifically, the first surface 21a is provided on one axial side (the stepping motor 40 side) of the rotary actuator 10, and spreads in a direction perpendicular to the axial direction of the rotary actuator 10. On the other hand, the second surface 21b is provided on the other axial side (the rotary member 30 side) of the rotary actuator 10, and spreads in a direction perpendicular to the axial direction of the rotary actuator 10.

[0018] The base ends of a plurality of fixed legs 22 are integrally provided on the first surface 21a of the base member 20. That is, the plurality of fixed legs 22 extend toward one axial side of the rotation actuator 10. The tip ends of the plurality of fixed legs 22 are fixed to a floor surface, a base, or the like (not shown) by base member fixing screws (not shown).

[0019] A stepping motor 40 is fixed to the first surface 21a of the base member 20, and the tip side of an output shaft 44 forming the stepping motor 40 passes through the annular main body 21 of the base member 20 and is disposed on the second surface 21b side of the annular main body 21. A pinion gear 45 is fixed to the output shaft 44 on the second surface 21b side. That is, the pinion gear 45 is freely rotatable by the stepping motor 40 on the second surface 21b side.

[0020] Furthermore, a total of three boss portions 23 are integrally provided on the radially outer side of the second surface portion 21b of the base member 20. These boss portions 23 protrude at a predetermined height toward the other axial side (the rotating member 30 side) of the base member 20 and are substantially cylindrical. The total of three boss portions 23 are disposed at equal intervals (120 degree intervals) in the circumferential direction of the annular main body portion 21, and each of these boss portions 23 is provided with a female thread portion 23a. A ring-shaped member fixing screw S1 (see FIG. 7) for fixing the ring-shaped member 50 to the second surface portion 21b of the annular main body portion 21 is screwed into the female thread portion 23a.

[0021] Further, an annular bearing holder 24 is integrally provided on the radially inner side of the base member 20 on the second surface portion 21b side. A ball bearing BB (see FIGS. 2 and 4) that rotatably supports the rotating member 30 is attached to the bearing holder 24. Specifically, the bearing holder 24 has a substantially L-shaped cross section and includes an annular bottom wall 24a and an annular side wall 24b. The annular bottom wall 24a supports an outer race OR of the ball bearing BB in the axial direction, and the annular side wall 24b supports the outer race OR of the ball bearing BB in the radial direction.

[0022] The inner race IR of the ball bearing BB is mounted on a bearing mounting portion 33 of the rotating member 30. The inner race IR of the ball bearing BB is sandwiched between the rotating member 30 and a retaining member 34. The annular bottom wall 24a of the bearing holder 24 is disposed between the outer race OR of the ball bearing BB and the retaining member 34. This allows the rotating member 30 to rotate smoothly relative to the base member 20 without coming off the base member 20.

[0023] Furthermore, a board pedestal 25 is provided integrally on the second surface portion 21b of the base member 20 and in the vicinity of the pinion gear 45 (stepping motor 40). The board pedestal 25 is formed in a substantially rectangular shape in a plan view, and protrudes at a predetermined height from the second surface portion 21b to the other axial side of the base member 20. Then, a switch board 26 fixed to a ring-shaped member 50 is placed on the board pedestal 25, as shown in FIG.

[0024] <Ring-shaped member> 2 to 7, a ring-shaped member 50 is attached to the second surface portion 21b of the base member 20. In other words, the ring-shaped member 50 constitutes a part of the base member 20, and is formed in a substantially flat plate shape from a resin material such as plastic. A first ring surface portion 50a is provided on one side surface of the ring-shaped member 50 (the lower side in FIG. 6), and a second ring surface portion 50b is provided on the other side surface of the ring-shaped member 50 (the upper side in FIG. 6).

[0025] The first ring surface portion 50a of the ring-shaped member 50 is provided with a board fixing recess 51 to which the switch board 26 is fixed. The board fixing recess 51 is recessed to a predetermined depth toward the second ring surface portion 50b of the ring-shaped member 50. Furthermore, a total of three female screw members 52 are provided by insert molding or the like at locations of the ring-shaped member 50 corresponding to the board fixing recess 51.

[0026] Here, the female screw member 52 is made of metal and formed in a substantially cylindrical shape, and a board fixing screw S2 for fixing the switch board 26 to the board fixing recess 51 is screwed into the female screw member 52. In this manner, the switch board 26 is supported at three points by the ring-shaped member 50 and is firmly fixed without any rattling.

[0027] 6, the second ring surface portion 50b of the ring-shaped member 50 is provided with a groove 53 that is formed in a substantially spiral shape when the base member 20 (ring-shaped member 50) is viewed from the other axial side (upper side in FIG. 7). That is, the groove 53 is provided in the portion (second ring surface portion 50b) of the ring-shaped member 50 that forms a part of the base member 20 and faces the rotating member 30.

[0028] The recessed groove 53 is recessed to a predetermined depth toward the first ring surface portion 50a of the ring-shaped member 50. Approximately half of the sphere 54 is movably fitted inside the recessed groove 53 (see FIG. 5), and the sphere 54 rolls inside the recessed groove 53 as the rotating member 30 rotates relative to the base member 20.

[0029] The ball 54 is made of metal (steel ball) and corresponds to the bridge member in the present invention.

[0030] Here, the groove 53 extends spirally in the circumferential direction of the ring-shaped member 50, i.e., in the rotational direction of the rotating member 30, and is provided over a range of approximately 380 degrees in the circumferential direction of the ring-shaped member 50. That is, the sphere 54 is movable from one side in the longitudinal direction of the groove 53 (see [0 degree] in FIG. 9) to the other side in the longitudinal direction (see [380 degrees] in FIG. 9) as the rotating member 30 rotates relative to the base member 20. This allows the rotating member 30 to rotate relative to the base member 20 within a rotation angle range of 360 degrees or more (approximately 380 degrees).

[0031] One-side groove end wall 53a forming one moving end of sphere 54 is provided at one longitudinal end of groove 53, i.e., near [0 degrees] (see FIG. 9), which is the reference rotation angle position of rotation member 30 relative to base member 20. Another-side groove end wall 53b forming the other moving end of sphere 54 is provided at the other longitudinal end of groove 53, i.e., near [380 degrees] (see FIG. 9), which is the maximum relative rotation angle position of rotation member 30 relative to base member 20.

[0032] Here, the one-side groove end wall 53a and the other-side groove end wall 53b are provided at both longitudinal ends of the groove 53 and are walls having substantially the same curvature as the sphere 54. This allows the sphere 54 to abut against the one-side groove end wall 53a and the other-side groove end wall 53b as the rotating member 30 rotates relative to the base member 20. The one-side groove end wall 53a and the other-side groove end wall 53b correspond to the abutting wall in the present invention.

[0033] Furthermore, the ring-shaped member 50 is provided with a total of three screw fixing holes 55 penetrating the ring-shaped member 50 in the axial direction. Specifically, these screw fixing holes 55 are arranged at equal intervals (120 degree intervals) in the circumferential direction of the ring-shaped member 50. Ring-shaped member fixing screws S1 are inserted into and fixed in these screw fixing holes 55. As a result, the ring-shaped member 50 is firmly fixed to the total of three boss portions 23 provided on the second surface portion 21b of the base member 20 without any rattling.

[0034] 2, in a state in which the ring-shaped member 50 is fixed to the base member 20, a part of the pinion gear 45 is exposed on the radially inner side of the ring-shaped member 50. As a result, the cylindrical large diameter gear 35 of the rotating member 30 disposed between the bearing holder 24 and the ring-shaped member 50 in the radial direction of the rotation actuator 10 is meshed with the pinion gear 45, as shown in FIG.

[0035] <Switch board> 5 and 6, the switch board 26 fixed to the board fixing recess 51 of the ring-shaped member 50 is made of a substantially rectangular PCB (Printed Circuit Board) and has one side board surface 26a and the other side board surface 26b. When the rotation actuator 10 is in an assembled state, the one side board surface 26a abuts against the board seat 25 of the base member 20, and the other side board surface 26b abuts against the board fixing recess 51 of the ring-shaped member 50.

[0036] A first detection switch 27 and a second detection switch 28 are mounted on the other board surface 26b of the switch board 26. Here, the first and second detection switches 27, 28 are both operated by a sphere 54 and are limit switches. Specifically, the first and second detection switches 27, 28 each have a pressing portion PS that is pressed by the sphere 54, and when these pressing portions PS are pressed by the sphere 54, the first and second detection switches 27, 28 generate an "ON signal."

[0037] 1, 2, and 4, the switch board 26 is electrically connected to the control unit CU via board wiring LN. This enables the control unit CU to grasp the operation states of the first and second detection switches 27, 28 by the sphere 54 and to control the rotation angle of the stepping motor 40 with high precision.

[0038] 3, in a state in which the rotary actuator 10 is assembled, the pressing portion PS of the first detection switch 27 is exposed on the front side of the one-side groove end wall 53a of the groove 53. In other words, the sphere 54 is able to operate the pressing portion PS of the first detection switch 27 before moving inside the groove 53 and coming into contact with the one-side groove end wall 53a.

[0039] On the other hand, in a state in which the rotary actuator 10 is assembled, the pressing portion PS of the second detection switch 28 is exposed on the front side of the other-side groove end wall 53b of the groove 53. In other words, the sphere 54 is able to operate the pressing portion PS of the second detection switch 28 before moving inside the groove 53 and coming into contact with the other-side groove end wall 53b.

[0040] In this way, the first and second detection switches 27, 28 operated by the sphere 54 are provided on both sides of the recessed groove 53 in the longitudinal direction, and these first and second detection switches 27, 28 correspond to the rotation detection switch in the present invention.

[0041] This enables the control unit CU to grasp that the sphere 54 has operated the pressing portion PS of the first detection switch 27, i.e., that the rotating member 30 is at the reference rotational angle position [0 degrees] relative to the base member 20, and based on this, can precisely control the rotation of the stepping motor 40 in the direction that adds (increases) the rotational angle.

[0042] On the other hand, the control unit CU can grasp that the sphere 54 has operated the pressing portion PS of the second detection switch 28, in other words, that the rotating member 30 is at the maximum relative rotation angle position [380 degrees] with respect to the base member 20, and can precisely control the rotation of the stepping motor 40 in the direction of subtracting (reducing) the rotation angle based on this.

[0043] Therefore, the control unit CU periodically rotates the rotating member 30 relative to the base member 20 and causes the sphere 54 to press the first detection switch 27 and the second detection switch 28, thereby automatically correcting the angular position of the stepping motor 40 to the correct position. This correction operation is an "automatic maintenance operation" that the control unit CU performs automatically through programming. Therefore, it does not require the user to take any trouble.

[0044] Here, the control unit CU has a memory (not shown) such as a RAM, and the memory stores the rotation angle of the output shaft 44 (see FIG. 2) of the stepping motor 40 and the rotation angle of the rotating member 30 relative to the base member 20 in association with each other. Therefore, the control unit CU can precisely control the rotation angle to increase from an angle position of [0 degrees] or decrease from an angle position of [380 degrees].

[0045] When linking the rotation angle of the output shaft 44 in the stepping motor 40 and the rotation angle of the rotating member 30 relative to the base member 20, the gear ratio (reduction ratio) of the pinion gear 45 and the cylindrical large diameter gear 35 and the like are taken into consideration.

[0046] Moreover, the first and second detection switches 27, 28 are mechanical switches that can be operated by the spheres 54. Therefore, compared to non-contact switches such as magnetic sensors and optical sensors, it is possible to generate "on signals" and "off signals" more reliably.

[0047] Furthermore, even if the control unit CU malfunctions due to overheating or the like and no longer recognizes the "on signal" and "off signal" from the first and second detection switches 27, 28, the sphere 54 moves inside the groove 53 between the one-side groove end wall 53a and the other-side groove end wall 53b as the rotating member 30 rotates relative to the base member 20. Thus, the sphere 54 comes into contact with the one-side groove end wall 53a or the other-side groove end wall 53b, preventing the rotating member 30 from rotating relative to the base member 20 by more than a specified rotation angle (fail-safe operation).

[0048] The rotational operation of the rotation member 30 relative to the base member 20 will be described in detail later.

[0049] 6, a total of three screw insertion holes 26c are provided in the switch board 26. These screw insertion holes 26c penetrate the switch board 26 in the plate thickness direction, and a board fixing screw S2 is inserted into each of the screw insertion holes 26c.

[0050] <Rotating parts> 1 to 5 and 8, the rotating member 30 is formed in a substantially disk-like shape from a resin material such as plastic. The rotating member 30 has a back surface portion 31 and a front surface portion 32. Specifically, the back surface portion 31 is provided on one axial side (the base member 20 side) of the rotating actuator 10, and extends in a direction perpendicular to the axial direction of the rotating actuator 10. On the other hand, the front surface portion 32 is provided on the other axial side (the opposite side to the base member 20 side) of the rotating actuator 10, and extends in a direction perpendicular to the axial direction of the rotating actuator 10.

[0051] 4 and 8, a bearing mounting portion 33 formed in a thick, generally cylindrical shape is integrally provided on the radially inner side of the back surface portion 31. An inner race IR of a ball bearing BB is mounted on the radially outer side of the bearing mounting portion 33. The other axial side of the inner race IR mounted on the bearing mounting portion 33 abuts against the rotating member 30.

[0052] Furthermore, a total of four female threaded holes 33a are provided on one axial side (the lower side in FIG. 4) of the bearing mounting portion 33. These female threaded holes 33a are provided at equal intervals (90 degree intervals) in the circumferential direction of the bearing mounting portion 33. Male threaded members S3 for fixing the retaining member 34 (see FIGS. 2 and 4) to the rotating member 30 are screwed into each female threaded hole 33a.

[0053] Here, the retaining member 34 has the function of preventing the ball bearing BB from falling out of the bearing mounting portion 33, and also prevents the rotating member 30 from coming off the base member 20. The retaining member 34 is formed in a substantially disk shape from a resin material such as plastic.

[0054] As shown in FIG. 4, the anti-slip member 34 includes a main body portion 34a through which the male thread member S3 is inserted, a small diameter cylindrical portion 34b that is integrally formed radially inside the main body portion 34a and protrudes toward the rotating member 30, a large diameter cylindrical portion 34c that is integrally formed radially outside the main body portion 34a and protrudes toward the rotating member 30, and a flange portion 34d that is positioned radially outside the main body portion 34a relative to the large diameter cylindrical portion 34c.

[0055] The small diameter cylindrical portion 34b fits into the radial inside of the bearing mounting portion 33 from one axial side. The large diameter cylindrical portion 34c, which has a diameter larger than that of the small diameter cylindrical portion 34b, supports one axial side of the inner race IR mounted on the bearing mounting portion 33. As a result, the inner race IR of the ball bearing BB is clamped between the rotating member 30 and the retaining member 34 by being screwed with the male thread member S3.

[0056] Furthermore, the flange portion 34d protrudes radially outward from the stopper member 34 and faces the annular bottom wall 24a in the axial direction of the rotating member 30. Specifically, the flange portion 34d is disposed on one axial side of the rotating member 30, and the annular bottom wall 24a is disposed on the other axial side of the rotating member 30. As a result, the annular bottom wall 24a is disposed between the flange portion 34d and the outer race OR of the ball bearing BB, thereby preventing the rotating member 30 from coming off the base member 20.

[0057] 8, a cylindrical large diameter gear 35 is integrally provided on the back surface 31 of the rotating member 30, radially outward of the bearing mounting portion 33. A plurality of gear teeth 35a that mesh with a pinion gear 45 (see FIG. 7) are provided on the outer periphery of the cylindrical large diameter gear 35. Here, the number of teeth of the gear teeth 35a is greater than the number of teeth of the pinion gear 45, so that the cylindrical large diameter gear 35 rotates at a slower speed and with a higher torque than the pinion gear 45.

[0058] In this way, the pinion gear 45 and the cylindrical large diameter gear 35 form a speed reduction mechanism. In addition, in the radial direction of the rotation actuator 10, the bearing holder 24 and the ball bearing BB are disposed radially inside the cylindrical large diameter gear 35.

[0059] 8, a sphere holding portion 36 consisting of a protrusion formed in a substantially oval shape is integrally provided on the radially outer side of the cylindrical large diameter gear 35. The sphere holding portion 36 protrudes at a predetermined height toward one axial side of the rotating member 30 and extends in the radial direction of the rotating member 30. Approximately half of the sphere 54 is movably inserted inside the sphere holding portion 36 (see FIG. 5). That is, the sphere 54 is held by the sphere holding portion 36 and provided on the portion (rear surface portion 31) of the rotating member 30 facing the base member 20.

[0060] Here, the sphere holding portion 36 is provided in the portion (rear surface portion 31) facing the recessed groove 53 of the rotating member 30, extends radially of the rotating member 30, and holds the sphere 54 movably, and corresponds to the holding groove in the present invention.

[0061] Specifically, the sphere holding portion 36 holds the sphere 54 so as to be movable only in the radial direction of the rotating member 30 relative to the rotating member 30. In other words, the sphere 54 is movable only in the radial direction of the rotating member 30 relative to the rotating member 30, and is immovable in the circumferential direction of the rotating member 30. As a result, the sphere 54 is rotated by the rotating member 30 as the rotating member 30 rotates relative to the base member 20, and rolls inside the recessed groove 53. At this time, the sphere 54 moves inside the sphere holding portion 36 as it moves inside the recessed groove 53, which is formed in a substantially spiral shape.

[0062] A through hole 36a that passes through the rotating member 30 in the axial direction is provided at a location corresponding to the inside of the sphere holding portion 36 of the rotating member 30. This through hole 36a is a hole for inserting the sphere 54 between the recessed groove 53 and the sphere holding portion 36 in a state in which the rotating member 30 is assembled to the base member 20. A cap CP is attached to the through hole 36a, and the cap CP is covered with a seal member SL.

[0063] <Operation of the Rotary Actuator> Next, an example of the operation of the rotary actuator 10 formed as above will be described in detail with reference to FIG.

[0064] First, the rotary actuator 10 is in a state in which the rotary member 30 is stopped at a reference rotation angle position [0 degrees] relative to the base member 20, as shown by the dashed circle [0 degrees] in Fig. 9. At this time, the sphere 54 is slightly in front of one side groove end wall 53a of the groove 53, and is in a state in which the pressing portion PS of the first detection switch 27 is pressed. Note that the sphere 54 is disposed radially outward from the sphere holding portion 36. In other words, the one side groove end wall 53a of the groove 53 formed in a substantially spiral shape is disposed radially outward from the other side groove end wall 53b of the ring-shaped member 50.

[0065] Next, the control unit CU controls the rotation of the stepping motor 40 to rotate the rotating member 30 clockwise relative to the base member 20, rotating it in a direction that adds a rotation angle from [0 degrees] to a rotation angle position of [100 degrees], resulting in the state shown by the dashed circle [100 degrees] in Fig. 9. In other words, the sphere 54 is rotated by the rotating member 30, rolls inside the recessed groove 53, and moves to approximately the center in the longitudinal direction of the sphere holding portion 36.

[0066] Thereafter, the control unit CU further controls the rotation of the stepping motor 40 to rotate the rotating member 30 clockwise relative to the base member 20, and rotates the rotating member 30 in a direction that adds a rotation angle from [100 degrees] to a rotation angle position of [190 degrees], resulting in a state shown by the dashed circle [190 degrees] in Fig. 9. That is, the sphere 54 is further rotated by the rotating member 30 and further rolls inside the recessed groove 53. Then, the sphere 54 moves toward the cylindrical large diameter gear 35 from approximately the center in the longitudinal direction of the sphere holding portion 36.

[0067] Furthermore, when the control unit CU continues to control the rotation of the stepping motor 40 to rotate the rotating member 30 clockwise relative to the base member 20, in a direction that adds a rotation angle from [190 degrees] to a rotation angle position of [280 degrees], the state is as shown by the dashed circle [280 degrees] in Fig. 9. That is, the sphere 54 is further rotated by the rotating member 30 and rolls further inside the recessed groove 53. Then, the sphere 54 moves closer to the cylindrical large diameter gear 35 relative to the sphere holding portion 36 than in the above-mentioned case of [190 degrees].

[0068] Next, the control unit CU further controls the rotation of the stepping motor 40 to rotate the rotating member 30 clockwise relative to the base member 20, in a direction that adds a rotation angle from [280 degrees] to a rotation angle position of [380 degrees], resulting in a state shown by the dashed circle [380 degrees] in Fig. 9. That is, the sphere 54 is further rotated by the rotating member 30 and rolls further inside the recessed groove 53. Then, the sphere 54 moves further toward the cylindrical large diameter gear 35 relative to the sphere holding portion 36 than in the above-mentioned case of [280 degrees].

[0069] Then, when the sphere 54 presses the pressing portion PS of the second detection switch 28 and an "ON signal" is input, the control unit CU stops the rotation control of the stepping motor 40. Therefore, the rotating member 30 is stopped at the maximum relative rotation angle position [380 degrees] with respect to the base member 20.

[0070] In this way, the control unit CU can control the rotation of the rotation member 30 relative to the base member 20 within an angular range from [0 degrees] to [380 degrees]. Of course, the control unit CU can control the rotation angle of the rotation member 30 relative to the base member 20 to be increased from the angular position of [0 degrees] or decreased from the angular position of [380 degrees], and can arbitrarily control the rotation angle of the rotation member 30 relative to the base member 20. Therefore, the rotation actuator 10 is suitable for use as a drive source for rotating an antenna capable of receiving millimeter waves, for example, in a direction where the signal strength is strong.

[0071] As described above in detail, the rotary actuator 10 of embodiment 1 is provided with a groove 53 which is provided on the second ring surface portion 50b which is the portion of the base member 20 which faces the rotating member 30 and extends in the rotational direction of the rotating member 30, a sphere 54 which is provided on the back surface portion 31 which is the portion of the rotating member 30 which faces the base member 20 and moves inside the groove 53 as the rotating member 30 rotates relative to the base member 20, and first and second detection switches 27, 28 which are provided on both longitudinal sides of the groove 53 and are operated by the sphere 54.

[0072] This allows the control unit CU to grasp that the sphere 54 has operated the pressing portion PS of the first detection switch 27, i.e., that the rotating member 30 is at a reference rotation angle position [0 degrees] relative to the base member 20, and to precisely control the rotation of the stepping motor 40 in a direction that adds (increases) the rotation angle based on this reference. On the other hand, the control unit CU grasps that the sphere 54 has operated the pressing portion PS of the second detection switch 28, i.e., that the rotating member 30 is at the maximum relative rotation angle position [380 degrees] relative to the base member 20, and to precisely control the rotation of the stepping motor 40 in a direction that subtracts (decreases) the rotation angle based on this reference.

[0073] Therefore, by periodically rotating the rotating member 30 relative to the base member 20 using the control unit CU and causing the sphere 54 to press the first detection switch 27 and the second detection switch 28, it becomes possible to correct the angular position of the stepping motor 40 to the correct position. Thus, it is possible to realize a rotation actuator 10 that allows for improved maintainability.

[0074] Furthermore, according to the rotary actuator 10 of embodiment 1, the groove 53 is formed in a spiral shape when the base member 20 is viewed from the axial direction, and the sphere 54 is movable only in the radial direction of the rotary member 30 relative to the rotary member 30.

[0075] As a result, as the rotating member 30 rotates relative to the base member 20, the spheres 54 are rotated by the rotating member 30 and roll inside the recessed grooves 53 of the base member 20. Therefore, the rotating member 30 can be rotated relative to the base member 20 within the angle range (prescribed angle range) of the recessed grooves 53 formed in a substantially spiral shape.

[0076] Furthermore, according to the rotary actuator 10 of embodiment 1, the back surface portion 31, which faces the recessed groove 53 of the rotary member 30, is provided with a sphere holding portion 36 that extends radially of the rotary member 30 and holds the sphere 54 in a freely movable manner.

[0077] As a result, the sphere 54 can move in the radial direction relative to the rotating member 30 while rolling inside the groove 53 that is formed in a substantially spiral shape.

[0078] Furthermore, according to the rotary actuator 10 of embodiment 1, both longitudinal ends of the groove 53 are provided with one-side groove end wall 53a and other-side groove end wall 53b against which the sphere 54 can abut as the rotating member 30 rotates relative to the base member 20.

[0079] As a result, even if the control unit CU malfunctions due to overheating or the like and no longer recognizes the "on signal" and "off signal" from the first and second detection switches 27, 28, the sphere 54 moves inside the groove 53 between the one-side groove end wall 53a and the other-side groove end wall 53b as the rotating member 30 rotates relative to the base member 20. This makes it possible to prevent the rotating member 30 from rotating relative to the base member 20 beyond a specified rotation angle (fail-safe operation).

[0080] Furthermore, according to the rotary actuator 10 of the first embodiment, the sphere 54 is capable of operating the first and second detection switches 27, 28 before coming into contact with the one-side groove end wall 53a and the other-side groove end wall 53b.

[0081] This allows the control unit CU to control (stop or reverse) the stepping motor 40 before the sphere 54 abuts against the one-side groove end wall 53a and the other-side groove end wall 53b, thereby preventing the sphere 54 and the groove 53 from being damaged.

[0082] Furthermore, according to the rotary actuator 10 of the first embodiment, the sphere 54 capable of rolling inside the recessed groove 53 is employed, and therefore the sphere 54 can roll inside the recessed groove 53 and inside the sphere holding portion 36. This makes it possible to suppress an increase in the rotational resistance of the rotary member 30 relative to the base member 20, and thus makes it possible to employ a smaller stepping motor 40 as the drive source.

[0083] Furthermore, according to the rotation actuator 10 of the first embodiment, the stepping motor 40 capable of controlling the rotation angle of the rotation shaft is adopted as the drive source of the rotation actuator 10. This makes it possible to finely and precisely adjust the rotation angle position of the rotation member 30 relative to the base member 20.

[0084] <Embodiment 2> FIG. 10 is an exploded oblique view showing a rotary actuator of embodiment 2 (rotating member omitted), FIG. 11 is an enlarged plan view (rotating member omitted) of the portion of the rotary actuator of FIG. 10 corresponding to the first switch board and the second switch board, and FIG. 12 is an enlarged oblique view explaining a method of adjusting the position of the first switch board and the second switch board relative to the ring-shaped member.

[0085] It should be noted that the same reference numerals are used to designate parts having the same functions as those in the first embodiment described above, and detailed descriptions thereof will be omitted.

[0086] 10 to 12, the rotary actuator 60 of the second embodiment differs from the rotary actuator 10 of the first embodiment in that it has a pair of a first switch board 70 and a second switch board 80. Another difference is that the first and second switch boards 70, 80 are each fixed to the board seat 25 of the base member 20 by a total of three board fixing screws S4.

[0087] Another difference is that the first and second switch boards 70, 80 are provided with a jig insertion hole HL for adjusting the positions of the first and second switch boards 70, 80 with respect to the board base 25. Another difference is that another pinion gear PG is provided between the pinion gear 45 of the stepping motor 40 and the cylindrical large diameter gear 35 of the rotating member 30 (see FIG. 8).

[0088] Specifically, the first switch board 70 has a first detection switch 27 mounted thereon. That is, the first switch board 70 is disposed in the vicinity of one-side groove end wall 53a of the groove 53. On the other hand, the second switch board 80 has a second detection switch 28 mounted thereon. That is, the second switch board 80 is disposed in the vicinity of the other-side groove end wall 53b of the groove 53.

[0089] Here, first detection switch 27 in embodiment 2 is disposed on one side in the longitudinal direction of groove 53, and corresponds to the rotation detection switch and the first switch in the present invention. Also, second detection switch 28 in embodiment 2 is disposed on the other side in the longitudinal direction of groove 53, and corresponds to the rotation detection switch and the second switch in the present invention.

[0090] The first and second switch boards 70, 80 are each provided with a total of three oblong holes 71, 81, and board fixing screws S4 are inserted into these oblong holes 71, 81. In other words, when the board fixing screws S4 are temporarily fastened, the first and second switch boards 70, 80 are each movable relative to the board base 25. Specifically, when the board fixing screws S4 are temporarily fastened, the first and second switch boards 70, 80 are each movable in the direction in which the oblong holes 71, 81 extend.

[0091] Each of the board fixing screws S4 is screwed into a female thread 25a provided on the board base 25.

[0092] 11, the ring-shaped member 50 of the rotary actuator 60 of the second embodiment is provided with a pair of adjustment holes AH hollowed out in a substantially oval shape. One of the pair of adjustment holes AH is provided corresponding to the first switch board 70, and the other of the pair of adjustment holes AH is provided corresponding to the second switch board 80. When the rotary actuator 60 is in an assembled state, a jig insertion hole HL is disposed inside each of the adjustment holes AH.

[0093] Here, in the rotary actuator 60 of the second embodiment, by using a jig 90 as shown in Fig. 12, the positions of the first and second switch boards 70, 80 with respect to the board pedestal 25 can be adjusted. Specifically, the jig 90 is formed in a stepped, generally cylindrical shape, and includes a knob portion 91 with a large diameter and a first insertion portion 92 with a smaller diameter than the knob portion 91. The outer periphery of the knob portion 91 is provided with an iris knurling process (shaded portion in the figure) that functions as an anti-slip treatment.

[0094] In addition, a second insertion portion 93 is provided on the tip side of the first insertion portion 92 (lower side in Figure 12), which has a smaller diameter than the first insertion portion 92 and is positioned at a position offset (eccentric) relative to the central axis of the first insertion portion 92.

[0095] Then, with the first and second switch boards 70, 80 temporarily fixed to the board base 25, the first insertion portion 92 is inserted into the adjustment hole AH of the ring-shaped member 50, as shown by the dashed arrow M1 in Figure 12. Next, the second insertion portion 93 is inserted into the jig insertion hole HL of the first and second switch boards 70, 80.

[0096] Thereafter, the jig 90 is rotated as shown by the dashed arrow M2. As a result, the first and second switch boards 70, 80 are moved (slid) relative to the board base 25 as shown by the dashed arrow M3. Then, with the first and second switch boards 70, 80 positioned relative to the board base 25, the board fixing screw S4 is fully tightened into the female threaded portion 25a.

[0097] This allows the first and second switch boards 70, 80 to be positioned at any positions relative to the board base 25, and thus allows the positions of the first detection switch 27 and the second detection switch 28 relative to the recessed groove 53 to be individually adjusted. Thus, the operation timing of the first and second detection switches 27, 28 by the sphere 54 is adjusted.

[0098] As described above in detail, the second embodiment can achieve the same effects as the first embodiment. In addition, in the second embodiment, the positions of the first and second detection switches 27, 28 can be adjusted with respect to the recessed groove 53, so that the rotation angle range of the rotating member 30 with respect to the base member 20 can be adjusted. This makes it possible to meet a wider variety of needs.

[0099] In addition, since another pinion gear PG is provided between the pinion gear 45 and the cylindrical large diameter gear 35 (see FIG. 8) and meshes with it, it is possible to adjust the reduction ratio more precisely. Therefore, for example, it is possible to employ a smaller stepping motor 40.

[0100] The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiments, the rotary actuators 10 and 60 are used as a drive source for rotating an antenna capable of receiving millimeter waves in a direction in which the signal strength is strong, but the present invention is not limited to this, and can be suitably used for rotary actuators for other purposes, particularly those in which the rotation angle of the rotary member 30 relative to the base member 20 must be set with high precision.

[0101] In addition, in each of the above-described embodiments, a sphere 54 is used as the bridge member, but the present invention is not limited to this. For example, a shape other than a sphere, such as a rectangular prism or other polyhedral shape, can also be used as the bridge member.

[0102] Furthermore, in each of the above-mentioned embodiments, the rotation detection switch is a limit switch (mechanical switch) having a pressing portion PS, but the present invention is not limited to this, and other types of switches (non-contact switches, etc.) such as magnetic switches and optical switches can also be used. For example, when a magnetic switch is used, the bridge member can be made of metal to detect the approach of the bridge member, and when an optical switch is used, the bridge member can detect the blocking state of the light emitted by the optical switch.

[0103] In addition, the material, shape, dimensions, number, installation location, etc. of each component in each of the above-mentioned embodiments are arbitrary as long as the present invention can be achieved, and are not limited to the above-mentioned embodiments.

[0104] Furthermore, the present technology can be configured as follows.

[0105] (1) A rotary actuator having a base member, a rotating member rotatably supported on the base member, and an electric motor for rotating the rotating member, the rotary actuator further comprising: a groove provided on the base member facing the rotating member and extending in the direction of rotation of the rotating member; a bridge member provided on the rotating member facing the base member and moving within the groove as the rotating member rotates relative to the base member; and a rotation detection switch provided on both longitudinal sides of the groove and operated by the bridge member.

[0106] (2) The rotary actuator described in (1), wherein the groove is formed in a spiral shape when the base member is viewed from the axial direction, and the bridge member is movable only in the radial direction of the rotating member relative to the rotating member.

[0107] (3) The rotary actuator according to (2), wherein a holding groove is provided in a portion of the rotary member facing the recessed groove, the holding groove extending in a radial direction of the rotary member and holding the bridge member movably.

[0108] (4) A rotary actuator described in any one of (1) to (3), wherein abutment walls are provided at both longitudinal ends of the groove, against which the bridge member can abut as the rotating member rotates relative to the base member.

[0109] (5) The rotary actuator according to (4), wherein the piece member is capable of operating the rotation detection switch before the piece member abuts against the abutment wall portion.

[0110] (6) The rotary actuator according to any one of (1) to (5), wherein the piece member is a sphere capable of rolling inside the groove.

[0111] (7) The rotary actuator according to any one of (1) to (6), wherein the electric motor is a stepping motor capable of controlling a rotation angle of a rotary shaft.

[0112] (8) A rotary actuator described in any one of (1) to (7), wherein the rotation detection switch has a first switch arranged on one longitudinal side of the groove and a second switch arranged on the other longitudinal side of the groove, and the position of the first switch relative to the groove and the position of the second switch relative to the groove are each individually adjustable. [Explanation of symbols]

[0113] 10...rotary actuator, 20...base member, 21...annular main body portion, 21a...first surface portion, 21b...second surface portion, 22...fixed leg portion, 23...boss portion, 23a...female thread portion, 24...bearing holder portion, 24a...annular bottom wall, 24b...annular side wall, 25...substrate base, 25a...female thread portion, 26...switch substrate, 26a...one side substrate surface, 26b...other side substrate surface, 26c...screw insertion hole, 27...first detection switch (rotation detection switch, first switch), 28...second detection switch switch (rotation detection switch, second switch), 30...rotating member, 31...back surface portion, 32...surface portion, 33...bearing mounting portion, 33a...female thread hole, 34...preventive member, 34a...main body portion, 34b...small diameter cylindrical portion, 34c...large diameter cylindrical portion, 34d...flange portion, 35...cylindrical large diameter gear, 35a...gear teeth, 36...sphere holding portion (holding groove), 36a...through hole, 40...stepping motor (electric motor), 41...connector connection portion, 42...motor main body portion, 43 ...Planetary gear reduction portion, 43a...Mounting portion, 44...Output shaft (rotating shaft), 45...Pinion gear, 50...Ring-shaped member, 50a...First ring surface portion, 50b...Second ring surface portion, 51...Substrate fixing recess, 52...Internal thread member, 53...Groove, 53a...One side groove end wall (abutment wall portion), 53b...Other side groove end wall (abutment wall portion), 54...Sphere (bridge member), 55...Screw fixing hole, 60...Rotation actuator, 70...First switch board, 71...Elongated hole, 80...Second switch Circuit board, 81... slotted hole, 90... jig, 91... knob portion, 92... first insertion portion, 93... second insertion portion, AH... adjustment hole, BB... ball bearing, CP... cap, CU... control unit, HL... jig insertion hole, IR... inner race, LN... circuit board wiring, OR... outer race, PG... pinion gear, PS... pressure portion, S1... ring-shaped member fixing screw, S2... circuit board fixing screw, S3... male thread member, S4... circuit board fixing screw, SL... sealing member

Claims

1. A base member; a rotating member rotatably supported by the base member; an electric motor that rotates the rotating member; A rotary actuator having a recessed groove provided in a portion of the base member facing the rotating member and extending in a rotation direction of the rotating member; a bridge member provided at a portion of the rotating member facing the base member, the bridge member moving within the groove as the rotating member rotates relative to the base member; a rotation detection switch provided on each side of the groove in the longitudinal direction and operated by the bridge member; Equipped with Rotary actuator.

2. 2. The rotary actuator according to claim 1, The groove is formed in a spiral shape when the base member is viewed in the axial direction, The piece member is movable relative to the rotating member only in a radial direction of the rotating member. Rotary actuator.

3. 3. The rotary actuator according to claim 2, a retaining groove is provided at a portion of the rotating member facing the recessed groove, the retaining groove extending in a radial direction of the rotating member and retaining the bridge member so as to be freely movable; Rotary actuator.

4. 2. The rotary actuator according to claim 1, abutment walls are provided at both ends of the groove in the longitudinal direction, against which the bridge member can abut as the rotating member rotates relative to the base member; Rotary actuator.

5. 5. The rotary actuator according to claim 4, The piece member is capable of operating the rotation detection switch before abutting against the abutment wall portion. Rotary actuator.

6. 2. The rotary actuator according to claim 1, The piece member is a sphere that can roll inside the groove. Rotary actuator.

7. 2. The rotary actuator according to claim 1, The electric motor is a stepping motor capable of controlling the rotation angle of a rotation shaft. Rotary actuator.

8. 2. The rotary actuator according to claim 1, The rotation detection switch includes a first switch disposed on one side of the groove in a longitudinal direction and a second switch disposed on the other side of the groove in the longitudinal direction, a position of the first switch relative to the groove and a position of the second switch relative to the groove are individually adjustable; Rotary actuator.

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