JP2006340593A - Drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device whose leakage of magnetic flux is small and whose cost can be reduced. <P>SOLUTION: When a current is made to flow in coils 16 in the shutter board drive device 1, electromagnetic force acts on a rotor 12, and the rotor 12 and an arm part 19 rotate. Consequently, a side part of the arm part 19 stops at a position abutting against one side end part 151 of a through hole 15. Since magnetic attraction force acts between the rotor 12 and sides 143a and 143c even at such a stopping position, the rotor 12 will be kept in a state where the arm part 19 abuts against one side part 151 of the through hole 15, even if energization to the coils 16 is stopped. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a driving device that rotates movable members such as a camera shutter member, a diaphragm member, and an ND filter (attenuating filter) member over a predetermined angular range.

  Conventionally, as a driving device for rotating a movable member over a predetermined angular range, coils are arranged along the outer peripheral surface of the rotor and the end surfaces on both sides, and spaced apart in the circumferential direction around the rotor provided with permanent magnets. There has been proposed one in which a plurality of arcuate yoke pieces are arranged at the above positions. In such a drive device, the natural stop position of the rotor is defined by the magnetic attractive force generated between the magnetic pole of the rotor and the side end of the yoke piece when the rotor rotates to a predetermined angular position. (For example, refer to Patent Document 1).

Further, in Patent Document 1, as a conventional example, a ferromagnetic pin is set around the rotor, and the natural stop position of the rotor is defined by a magnetic attractive force generated between the pin and the rotor. Is disclosed.
Japanese Utility Model Publication No. 7-14443

  However, the technique disclosed in the above-mentioned patent document has a problem in that a plurality of arc-shaped yoke pieces are arranged at positions separated in the circumferential direction, so that the area where the yoke does not exist is wide and the leakage of magnetic flux is large. Further, in the configuration in which pins are added, there is a problem that an increase in the number of parts and a complicated configuration cannot be avoided, and the cost cannot be reduced.

  In view of the above problems, an object of the present invention is to provide a drive device that can reduce the leakage of magnetic flux and can reduce costs.

  In order to solve the above problems, in the present invention, a rotor having different magnetic poles in the circumferential direction, a coil that is arranged along the outer peripheral surface and both end faces of the rotor, and drives the rotor, In the driving apparatus including the yoke facing the outer peripheral surface of the rotor, the yoke is disposed so as to surround the rotor, and is close to the rotor at a predetermined position in the circumferential direction. And a first magnetic stopper and a second magnetic stopper for defining a natural stop position of the rotor by a magnetic attractive force generated between the coil and the rotor when the coil is not energized. It is characterized by.

  In the present invention, by bringing the yoke close to the rotor at a predetermined position in the circumferential direction, a magnetic attractive force is generated between the yoke and the rotor when the coil is not energized to define the natural stop position of the rotor. It constitutes a magnetic stopper. Therefore, according to the present invention, since the magnetic stopper can be configured only by using the yoke processed into a predetermined shape, it is not necessary to add a pin around the rotor. Therefore, the number of parts can be reduced, and the complexity of the configuration can be avoided, so that the cost can be reduced. In addition, since the magnetic stopper is configured only by the yoke partially approaching the rotor, unlike the configuration in which a plurality of arcuate yoke pieces are arranged at positions spaced apart in the circumferential direction, the magnetic stopper Since the yoke surrounds the entire periphery or substantially the entire periphery, there is an advantage that leakage of magnetic flux is small.

  In the present invention, the yoke is in proximity to the rotor between the first magnetic stopper and the second magnetic stopper in the circumferential direction, and between the rotor when the coil is not energized. It is preferable to include a third magnetic stopper that defines the natural stop position of the rotor by the generated magnetic attractive force. If comprised in this way, the natural stop position of a rotor can also be set three places.

  In the present invention, the first machine that directly or indirectly contacts the rotor and that defines a rotation angle range narrower than the rotation angle range of the rotor defined by the first and second magnetic stoppers. And a second mechanical stopper, and the rotor is held by the first magnetic stopper at a stop position defined by the first mechanical stopper even when the coil is not energized. On the other hand, it is preferable that the stop position defined by the second mechanical stopper is held by the second magnetic stopper. In such a configuration, the rotor stop position can be set at an arbitrary position regardless of the magnetic configuration. Also in this case, the rotor is held at the stop position defined by the mechanical stopper by the magnetic attractive force acting between the rotor and the magnetic stopper.

  In the present invention, a swinging member that outputs the rotation of the rotor extends radially outward from the rotor, while the yoke has a penetrating portion that pulls the swinging member to the outside of the yoke. When formed, each of the first and second mechanical stoppers includes a first end located on one side in the circumferential direction of the opening and a second end located on the other side. It is preferable.

  In the present invention, when the yoke has a substantially polygonal cross-section when cut in a direction perpendicular to the rotation axis, the magnetic stopper is constituted by a portion corresponding to the side of the polygon. Can do.

  In the present invention, when the yoke has a substantially polygonal cross-section when cut in a direction perpendicular to the rotation axis, the magnetic stopper protrudes inward from a portion corresponding to the side of the polygon. It can comprise by the protrusion to do.

  In the present invention, when the yoke has a substantially circular cross-section when cut in a direction orthogonal to the rotation axis, the magnetic stopper may be constituted by a protrusion protruding inward from the yoke. it can.

  In the driving apparatus according to the present invention, the yoke is brought close to the outer peripheral surface of the rotor at a predetermined position in the circumferential direction, thereby generating a magnetic attractive force between the yoke and the rotor when the coil is not energized. The magnetic stopper which prescribes | regulates the natural stop position of this is comprised. Therefore, according to the present invention, since the magnetic stopper can be configured simply by using the yoke processed into a predetermined shape, the number of parts can be reduced and the complexity of the configuration can be avoided, thereby reducing the cost. can do. In addition, since the magnetic stopper is configured only by the yoke partially approaching the rotor, the yoke surrounds the entire or substantially the entire periphery of the rotor, so that there is an advantage that leakage of magnetic flux is small.

[Embodiment 1]
(overall structure)
FIGS. 1A and 1B are a cross-sectional view and a vertical cross-sectional view, respectively, showing the configuration of the shutter plate driving device according to Embodiment 1 of the present invention. 2A and 2B are a cross-sectional view and a vertical cross-sectional view, respectively, showing the configuration of the motor device (drive device) that constitutes the drive unit of the shutter plate drive device shown in FIG. In the drawings used for the following description, arrows are attached to the circumferential center position of the N pole and the circumferential center position of the S pole.

  1A and 1B, a shutter plate driving device 1 according to the present embodiment is for opening and closing a diaphragm opening 4 by driving a shutter plate 3 in an imaging device such as a digital camera or a camera-equipped mobile phone. In the shutter plate driving device 1, a shutter plate 3 is disposed on the object side of a frame 2 that accommodates a lens and the like, and a motor device 10 is disposed on the side of the frame 2.

  As shown in FIGS. 2A and 2B, the motor device 10 includes a cylindrical rotor 12 having magnetic poles (N pole and S pole) that are different in the circumferential direction, an outer peripheral surface of the rotor 12, and A coil 16 disposed along the end surfaces on both sides and a yoke 14 facing the outer peripheral surface of the rotor 12 are provided.

  The rotor 12 includes a rotating shaft 121 having a large diameter portion 122 at the central portion in the axial direction, and a cylindrical permanent magnet 128 fixed around the large diameter portion 122 of the rotating shaft 121. The permanent magnet 128 has an N pole on one side across the rotation center axis L, and an S pole on the other side. In the rotor 12, an arm portion 19 (swing member) extends from one side in the axial direction, and the swinging motion of the arm portion 19 is transmitted directly or indirectly to the shutter plate 3 shown in FIG. It is like that.

  A first coil frame 17 and a second coil frame 18 are disposed on both sides of the rotor 12 in the axial direction. The first coil frame 17 is formed with a bearing hole 172 that rotatably supports one end side of the rotating shaft 121, and the second coil frame 18 rotatably supports the other end side of the rotating shaft 121. A bearing hole 182 is formed. The coil 16 is wound around the recess 174 of the first coil frame 17 and the recess 184 of the second coil frame 18. In this state, the coil 16 extends in parallel to the outer peripheral surface and both end surfaces of the rotor 12. Yes.

  When the yoke 14 is cut in a direction perpendicular to the rotation center axis L, the cut surface is a substantially square, and when the arm portion 19 is at an intermediate position indicated by a solid line in FIG. The center position in the direction and the center position in the circumferential direction of the S pole are in a state of facing the corner portions 141b and 141d among the four corner portions 141a, 141b, 141c, and 141d of the regular tetragon. Here, the central portions of the four sides 143a, 143b, 143c, and 143d of the yoke 14 are closer to the outer peripheral surface of the rotor 12 than the corner portions 141a, 141b, 141c, and 141d. Of the four sides 143a, 143b, 143c, and 143d, the central portion of the two sides 143b and 143d functions as a first magnetic stopper. That is, if the rotor 12 is rotated 45 ° clockwise CW, the center of the N pole of the rotor 12 approaches the side 143b, and the center of the S pole of the rotor 12 approaches the side 143d. The central portions of the two sides 143b and 143d function as a first magnetic stopper that defines the natural stop position of the rotor 12 by a magnetic attractive force generated between the two sides 143b and 143d. The remaining two sides 143a and 143c function as a second magnetic stopper. That is, when the rotor 12 rotates 45 ° counterclockwise CCW, the center of the north pole of the rotor 12 approaches the side 143a and the center of the south pole of the rotor 12 approaches the side 143c. The central part of the two sides 143a and 143c functions as a second magnetic stopper that defines the natural stop position of the rotor 12 by the magnetic attractive force generated between the sides.

  Further, a through hole 15 for pulling out the arm portion 19 outward in the radial direction is formed in the corner portion 141a and the sides 143a and 143d of the yoke 14 over a predetermined angular range. For this reason, when the rotor 12 rotates clockwise CW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 2A to the position shown by the dashed line in FIG. Since the side end portion of the arm portion 19 abuts on one side end portion 151 in the circumferential direction of the through hole 15, the one side end portion 151 functions as a first mechanical stopper. On the other hand, the rotor 12 moves counterclockwise CCW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 2A to the position shown by the two-dot chain line in FIG. When rotated, the side end portion on the opposite side of the arm portion 19 abuts on the other end portion 152 in the circumferential direction of the through hole 15, so that the other end portion 152 functions as a second mechanical stopper. . Here, the through hole 15 has a slit shape elongated in the circumferential direction, and the opening width in the axial direction is only slightly larger than the thickness dimension of the arm portion 19. For this reason, the yoke 14 is in a state of totally surrounding the rotor 14 including the portion where the through hole 15 is formed.

(Operation)
In the shutter plate driving device 1 configured as described above, assuming that the arm portion 19 is at an intermediate position indicated by a solid line in FIG. Electromagnetic force is applied according to Fleming's left-hand rule, and the rotor 12 and the arm portion 19 rotate clockwise CW. As shown in FIG. The portion stops at a position where it abuts against one end 151 (first mechanical stopper) of the through hole 15. Even in such a stop position, a magnetic attractive force acts between the rotating body 12 and the sides 143b and 143d (first magnetic stopper), so that even when the energization to the coil 16 is stopped, the rotation is performed. The body 12 is held in a stopped state at a position where the arm portion 19 is in contact with the one end portion 151 of the through hole 15. In this state, as shown in FIG. 1, the shutter plate 3 opens the aperture opening 4.

  When a current in the other direction is passed through the coil 16 from this state, electromagnetic force acts on the rotor 12 in accordance with Fleming's left-hand rule, and the rotor 12 and the arm portion 19 rotate counterclockwise CCW. 2 (a), the arm portion 19 stops at a position where the side end portion of the arm portion 19 abuts against the other end portion 152 (second mechanical stopper) of the through hole 15 as indicated by a two-dot chain line. . Even in such a stop position, a magnetic attractive force acts between the rotating body 12 and the sides 143a and 143c (second magnetic stoppers), so that even when the energization to the coil 12 is stopped, the rotation is performed. The body 12 is held in a stopped state at a position where the arm portion 19 is in contact with the other end 152 of the through hole 15. In this state, the shutter plate 3 closes the aperture opening 4 as shown in FIG.

  Therefore, by controlling the energization to the coil 16, the rotating body 12, the arm portion 19, and the shutter plate 3 can be rotated over a predetermined angle range, so that the aperture opening 4 can be opened and closed.

(Main effects of this form)
As described above, in the shutter plate driving device 1 of the present embodiment, the rotor 12 can be rotated by the coil 16 over a predetermined angle range, and the rotation angle range includes the end portion 151 of the through hole 15, It is defined by 152 (mechanical stopper) and is narrower than the rotation angle range of the rotor 12 defined by the sides 143a, 143b, 143c, 143d (magnetic stopper). Therefore, in the shutter plate driving device 1 of the present embodiment, the rotational angle range of the rotating body 12 can be arbitrarily set by the position of the mechanical stopper regardless of the magnetic configuration such as the shape of the yoke 14. it can. Even in this case, the rotor 12 is held by the magnetic stopper at the stop position defined by the mechanical stopper even when the coil 16 is not energized. Therefore, the shutter plate 3 can be reliably held in the open position or the closed position without using a complicated mechanism.

  Further, in this embodiment, the sides 143a, 143b, 143c, and 143d of the yoke 14 are brought close to the outer peripheral surface of the rotor 12 at predetermined positions in the circumferential direction, whereby the yoke 14 and the rotor 12 are not energized when the coil 16 is not energized. A magnetic stopper that defines a natural stop position of the rotor 12 by generating a magnetic attractive force therebetween is configured. Therefore, according to the present embodiment, since the magnetic stopper can be configured only by using the yoke 14 processed into a predetermined shape, it is not necessary to add a pin or the like around the rotor 12. Therefore, the number of parts can be reduced, and the complexity of the configuration can be avoided, so that the cost can be reduced.

  Further, since the magnetic stopper is configured only by the yoke 14 being partially close to the rotor 12, the magnetic stopper rotates unlike a configuration in which a plurality of arcuate yoke pieces are arranged at positions spaced apart in the circumferential direction. Since the entire periphery of the child 12 is surrounded by the yoke 14, there is an advantage that leakage of magnetic flux is small.

[Modification of Embodiment 1]
FIG. 3 is a cross-sectional view showing a configuration of a motor device (drive device) that constitutes a drive unit of a shutter plate drive device according to a modification of the first embodiment of the present invention. Since the basic configuration of the motor device of this embodiment and any of the embodiments to be described later is the same as that of the first embodiment, common portions are denoted by the same reference numerals and illustrated. Detailed description is omitted.

  In the motor device 10 shown in FIG. 3, the yoke 14 has a substantially regular hexagonal cut surface when cut in a direction perpendicular to the rotation center axis L, and the arm portion 19 is at an intermediate position shown by a solid line in FIG. The central position in the circumferential direction of the N pole and the central position in the circumferential direction of the S pole are directed to the corner portions 141b and 141e among the six regular hexagonal corner portions 141a, 141b, 141c, 141d, 141e, and 141f. Is in a state. Here, the central part of the six sides 143a, 143b, 143c, 143d, 143e, 143f of the yoke 14 is closer to the outer peripheral surface of the rotor 12 than the corners 141a, 141b, 141c, 141d, 141e, 141f. In this embodiment, of the six sides 143a, 143b, 143c, 143d, 143e, 143f, the central portion of the two sides 143b, 143c functions as a first magnetic stopper, and the two sides 143a, 143d functions as a second magnetic stopper.

  Further, in the present embodiment, a through hole 15 for pulling out the arm portion 19 radially outward is formed over a predetermined angular range with respect to the side 143f of the yoke 14. For this reason, when the rotor 12 rotates clockwise CW so that the arm part 19 moves from the intermediate position shown by the solid line in FIG. 3 to the position shown by the alternate long and short dash line in FIG. Since the portion abuts on one end 151 in the circumferential direction of the through hole 15, the one end 151 functions as a first mechanical stopper. On the other hand, when the rotor 12 rotates counterclockwise CCW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 3 to the position shown by the two-dot chain line in FIG. Since the side end portion on the opposite side of 19 abuts on the other end portion 152 in the circumferential direction of the through hole 15, the other end portion 152 functions as a second mechanical stopper.

  Even in the shutter plate driving apparatus configured as described above, the rotor 12 is held by the magnetic stopper at the stop position defined by the mechanical stopper even when the coil 16 is not energized. Therefore, the shutter plate 3 can be held in the open position or the closed position without using a complicated mechanism.

  The through hole 15 has a slit shape elongated in the circumferential direction, and the opening width in the axial direction is only slightly larger than the thickness of the arm portion 19. Therefore, there is no hindrance for the side 14f of the yoke 14 to function as the second magnetic stopper, and the yoke 14 includes the entire portion around the rotor 14 including the portion where the through hole 15 is formed. In an enclosed state.

[Embodiment 2]
FIG. 4 is a cross-sectional view showing the configuration of a motor device (drive device) that constitutes the drive unit of the shutter plate drive device according to Embodiment 2 of the present invention.

  In the motor apparatus 10 shown in FIG. 4, the yoke 14 has a substantially regular square cut surface when cut in a direction perpendicular to the rotation center axis L, and the arm portion 19 is at an intermediate position shown by a solid line in FIG. 4. At this time, the center position in the circumferential direction of the N pole and the center position in the circumferential direction of the S pole are in a state facing the corner portions 141b and 141d among the four corner portions 141a, 141b, 141c, and 141d of a regular square. Here, protrusions 145a, 145b, 145c, and 145d that protrude inward are formed at the center of the four sides 143a, 143b, 143c, and 143d of the yoke 14 by pressing the yoke 14 or the like. These protrusions 145a, 145b, 145c, and 145d are closer to the outer peripheral surface of the rotor 12 than the peripheral portion. In this embodiment, two of the four protrusions 145a, 145b, 145c, and 145d The two protrusions 145b and 145d function as a first magnetic stopper. That is, when the rotor 12 rotates clockwise CW and the arm portion 19 moves from the position indicated by the solid line in FIG. 4 to the position indicated by the alternate long and short dash line, the center of the N pole of the rotor 12 approaches the protrusion 145b. In addition, since the center of the south pole of the rotor 12 approaches the protrusion 145d, the two protrusions 145b and 145d are positioned at the natural stop position of the rotor 12 by the magnetic attractive force generated between the rotor 12 and the two protrusions 145b and 145d. It functions as a first magnetic stopper that defines The remaining two protrusions 145a and 145c function as a second magnetic stopper. That is, when the rotor 12 rotates counterclockwise CCW and the arm portion 19 moves from the position indicated by the solid line in FIG. 4 to the position indicated by the two-dot chain line, the center of the N pole of the rotor 12 becomes the protrusion 145a. Since the center of the south pole of the rotor 12 approaches the protrusion 145c, the two protrusions 145a and 145c are separated from each other by the magnetic attraction force generated between the rotor 12 and the rotor 12. It functions as a second magnetic stopper that defines the stop position.

  Also in this embodiment, the through hole 15 for pulling out the arm portion 19 outward in the radial direction is formed over a predetermined angular range with respect to the corner portion 141a and the sides 143a and 143d of the yoke 14. For this reason, when the rotor 12 rotates clockwise CW so that the arm part 19 moves from the intermediate position shown by the solid line in FIG. 4 to the position shown by the alternate long and short dash line in FIG. Since the portion abuts on one end 151 in the circumferential direction of the through hole 15, the one end 151 functions as a first mechanical stopper. On the other hand, when the rotor 12 rotates counterclockwise CCW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 4 to the position shown by the two-dot chain line in FIG. Since the side end portion on the opposite side of 19 abuts on the other end portion 152 in the circumferential direction of the through hole 15, the other end portion 152 functions as a second mechanical stopper.

  Even in the shutter plate driving apparatus configured as described above, the rotor 12 is held by the magnetic stopper at the stop position defined by the mechanical stopper even when the coil 16 is not energized. Therefore, the shutter plate 3 can be held in the open position or the closed position without using a complicated mechanism.

  The through hole 15 has a slit shape elongated in the circumferential direction, and the opening width in the axial direction is only slightly larger than the thickness of the arm portion 19. For this reason, the yoke 14 is in a state of totally surrounding the rotor 14 including the portion where the through hole 15 is formed.

  Even with the shutter plate driving device 1 configured as described above, the shutter plate 3 can be held in the open position or the closed position without using a complicated mechanism, and the entire periphery of the rotor 12 is surrounded by the yoke 14. Therefore, the same effects as those of the first embodiment are obtained, such as a small leakage of magnetic flux.

[Modification of Embodiment 2]
FIG. 5 is a cross-sectional view showing a configuration of a motor device (drive device) that constitutes a drive unit of a shutter plate drive device according to a modification of the second embodiment of the present invention.

  In the motor device 10 shown in FIG. 5, the yoke 14 has a substantially regular hexagonal cut surface when cut in a direction orthogonal to the rotation center axis L, and the arm portion 19 is at an intermediate position shown by a solid line in FIG. At this time, the center position in the circumferential direction of the N pole and the center position in the circumferential direction of the S pole are in a state facing the four corners 141a, 141b, 141c, and 141d of a regular square. Here, at the central part of the six sides 143a, 143b, 143c, 143d, 143e, 143f of the yoke 14, protrusions 145a, 145b, 145c, 145d, 145e, 145f is formed. These protrusions 145a, 145b, 145c, 145d, 145e, and 145f are closer to the outer peripheral surface of the rotor 12 as compared with the peripheral portion. In this embodiment, the six protrusions 145a, 145b, 145c, and 145d are provided. Two projections 145b and 145e out of 145e and 145f function as a first magnetic stopper. The two protrusions 145a and 145d function as a second magnetic stopper.

  Also in this embodiment, a through hole 15 for pulling out the arm portion 19 outward in the radial direction is formed on the side 143f of the yoke 14 over a predetermined angular range. For this reason, when the rotor 12 rotates clockwise CW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 5 to the position shown by the alternate long and short dash line in FIG. Since the portion abuts on one end 151 in the circumferential direction of the through hole 15, the one end 151 functions as a first mechanical stopper. On the other hand, when the rotor 12 rotates counterclockwise CCW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 5 to the position shown by the two-dot chain line in FIG. Since the side end portion on the opposite side of 19 abuts on the other end portion 152 in the circumferential direction of the through hole 15, the other end portion 152 functions as a second mechanical stopper.

  Even in the shutter plate driving apparatus configured as described above, the rotor 12 is held by the magnetic stopper at the stop position defined by the mechanical stopper even when the coil 16 is not energized. Therefore, the shutter plate 3 can be held in the open position or the closed position without using a complicated mechanism.

  The through hole 15 has a slit shape elongated in the circumferential direction, and the opening width in the axial direction is only slightly larger than the thickness dimension of the arm portion 19. For this reason, the yoke 14 is in a state of totally surrounding the rotor 14 including the portion where the through hole 15 is formed.

[Embodiment 3]
FIG. 6 is a longitudinal sectional view showing a configuration of a motor device (drive device) that constitutes the drive unit of the shutter plate drive device according to Embodiment 3 of the present invention.

  In the motor device 10 shown in FIG. 6, the yoke 14 has a substantially circular cut surface when cut in a direction orthogonal to the rotation center axis L, and the yoke 14 is inwardly formed by pressing the yoke 14 or the like. Four protruding portions 145a, 145b, 145c, and 145d are formed at equal angular intervals. These protrusions 145a, 145b, 145c, and 145d are closer to the outer peripheral surface of the rotor 12 than the peripheral portion. Here, when the arm portion 19 is at the intermediate position shown by the solid line in FIG. 6, the center position in the circumferential direction of the N pole and the center position in the circumferential direction of the S pole are respectively the protrusion 145a and the protrusion 145b. And between the protrusion 145c and the protrusion 145d. Therefore, in this embodiment, of the four protrusions 145a, 145b, 145c, and 145d, the two protrusions 145b and 145d function as a first magnetic stopper. That is, if the rotor 12 is rotated 45 ° clockwise CW, the center of the N pole of the rotor 12 approaches the protrusion 145b, and the center of the S pole of the rotor 12 approaches the protrusion 145d. Therefore, the two protrusions 145b and 145d function as a first magnetic stopper that defines the natural stop position of the rotor 12 by the magnetic attractive force generated between the rotor 12 and the two protrusions 145b and 145d. The remaining two protrusions 145a and 145c function as a second magnetic stopper. That is, if the rotor 12 rotates 45 ° counterclockwise CCW, the center of the N pole of the rotor 12 approaches the protrusion 145a, and the center of the S pole of the rotor 12 approaches the protrusion 145c. Therefore, the two protrusions 145a and 145c function as a second magnetic stopper that defines the natural stop position of the rotor 12 by the magnetic attraction generated between the rotor 12 and the two protrusions 145a and 145c.

  Also in the yoke 14 of this embodiment, a through hole 15 for pulling out the arm portion 19 outward in the radial direction is formed over a predetermined angular range between the protrusion 145a and the protrusion 145d. For this reason, when the rotor 12 rotates clockwise CW so that the arm part 19 moves from the intermediate position shown by the solid line in FIG. 6 to the position shown by the alternate long and short dash line in FIG. Since the portion abuts on one end 151 in the circumferential direction of the through hole 15, the one end 151 functions as a first mechanical stopper. On the other hand, when the rotor 12 rotates counterclockwise CCW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 6 to the position shown by the two-dot chain line in FIG. Since the side end portion on the opposite side of 19 abuts on the other end portion 152 in the circumferential direction of the through hole 15, the other end portion 152 functions as a second mechanical stopper.

  Even in the shutter plate driving apparatus configured as described above, the rotor 12 is held by the magnetic stopper at the stop position defined by the mechanical stopper even when the coil 16 is not energized. Therefore, the shutter plate 3 can be held in the open position or the closed position without using a complicated mechanism.

  The through hole 15 has a slit shape elongated in the circumferential direction, and the opening width in the axial direction is only slightly larger than the thickness of the arm portion 19. For this reason, the yoke 14 is in a state of totally surrounding the rotor 14 including the portion where the through hole 15 is formed.

[Modification of Embodiment 3]
FIG. 7 is a longitudinal sectional view showing a configuration of a motor device (drive device) that constitutes the drive unit of the shutter plate drive device according to Embodiment 4 of the present invention.

  In the motor device 10 shown in FIG. 7, the yoke 14 has a substantially circular cut surface when cut in a direction orthogonal to the rotation center axis L, and the yoke 14 is inwardly formed by pressing the yoke 14 or the like. Six protruding protrusions 145a, 145b, 145c, 145d, 145e, and 145f are formed at equiangular intervals. These protrusions 145a, 145b, 145c, 145d, 145e, and 145f are closer to the outer peripheral surface of the rotor 12 than the peripheral portion. Here, when the arm portion 19 is at the intermediate position shown by the solid line in FIG. 7, the center position in the circumferential direction of the N pole and the center position in the circumferential direction of the S pole are respectively the protrusion 145a and the protrusion 145b. And between the protrusions 145d and 145e. Therefore, in this embodiment, of the six protrusions 145a, 145b, 145c, 145d, 145e, and 145f, the two protrusions 145b and 145e function as the first magnetic stopper, and the two protrusions 145a and 145d It functions as a second magnetic stopper.

  Also in the yoke 14 of the present embodiment, a through hole 15 for pulling out the arm portion 19 radially outward is formed in the vicinity of the projection 145f formed over a predetermined angular range. For this reason, when the rotor 12 rotates clockwise CW so that the arm part 19 moves from the intermediate position shown by the solid line in FIG. 7 to the position shown by the alternate long and short dash line in FIG. Since the portion abuts on one end 151 in the circumferential direction of the through hole 15, the one end 151 functions as a first mechanical stopper. On the other hand, when the rotor 12 rotates counterclockwise CCW so that the arm portion 19 moves from the intermediate position shown by the solid line in FIG. 7 to the position shown by the two-dot chain line in FIG. Since the side end portion on the opposite side of 19 abuts on the other end portion 152 in the circumferential direction of the through hole 15, the other end portion 152 functions as a second mechanical stopper.

  Even in the shutter plate driving apparatus configured as described above, the rotor 12 is held by the magnetic stopper at the stop position defined by the mechanical stopper even when the coil 16 is not energized. Therefore, the shutter plate 3 can be held in the open position or the closed position without using a complicated mechanism.

  The through hole 15 has a slit shape elongated in the circumferential direction, and the opening width in the axial direction is only slightly larger than the thickness of the arm portion 19. For this reason, the yoke 14 is in a state of totally surrounding the rotor 14 including the portion where the through hole 15 is formed.

[Embodiment 4]
FIG. 8 is a cross-sectional view showing the configuration of a motor device (drive device) that constitutes the drive unit of the shutter plate drive device according to Embodiment 4 of the present invention.

  In the motor device 10 shown in FIG. 8, the yoke 14 has a substantially regular hexagonal cut surface when cut in a direction perpendicular to the rotation center axis L, and the arm portion 19 is at an intermediate position shown by a solid line in FIG. At this time, the center position in the circumferential direction of the N pole and the center position in the circumferential direction of the S pole are in a state facing the regular hexagonal sides 143a and 143d. Here, the central part of the six sides 143a, 143b, 143c, 143d, 143e, 143f of the yoke 14 is closer to the outer peripheral surface of the rotor 12 than the corners 141a, 141b, 141c, 141d, 141e, 141f. In this embodiment, of the six sides 143a, 143b, 143c, 143d, 143e, 143f, the central portion of the two sides 143b, 143e functions as a first magnetic stopper, and the two sides 143f, 143c functions as a second magnetic stopper.

  Further, in this embodiment, the through holes 15 for pulling out the arm portions 19 outward in the radial direction are formed in the sides 143a, 143f, and 143e of the yoke 14 over a predetermined angular range. For this reason, when the rotor 12 rotates clockwise CW so that the arm part 19 moves from the intermediate position shown by the solid line in FIG. 8 to the position shown by the alternate long and short dash line in FIG. Since the portion abuts on one end 151 in the circumferential direction of the through hole 15, the one end 151 functions as a first mechanical stopper. On the other hand, when the rotor 12 rotates counterclockwise CCW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 8 to the position shown by the two-dot chain line in FIG. Since the side end portion on the opposite side of 19 abuts on the other end portion 152 in the circumferential direction of the through hole 15, the other end portion 152 functions as a second mechanical stopper.

  Even in the shutter plate driving apparatus configured as described above, the rotor 12 is held by the magnetic stopper at the stop position defined by the mechanical stopper even when the coil 16 is not energized. Therefore, the shutter plate 3 can be held in the open position or the closed position without using a complicated mechanism.

  The through hole 15 has a slit shape elongated in the circumferential direction, and the opening width in the axial direction is only slightly larger than the thickness of the arm portion 19. For this reason, the yoke 14 is in a state of totally surrounding the rotor 14 including the portion where the through hole 15 is formed.

  Further, the central portion of the sides 143a and 143d of the yoke 14 is an intermediate position of the rotation angle range defined by the first and second mechanical stoppers (the rotation angle range defined by the first and second magnetic stoppers). The intermediate position) functions as a third magnetic stopper for holding the rotor 12. Therefore, even when energization of the coil 16 is stopped, the rotor 12 can be held at the three stop positions.

[Embodiment 5]
FIG. 9 is a longitudinal sectional view showing a configuration of a motor device (drive device) that constitutes the drive unit of the shutter plate drive device according to Embodiment 5 of the present invention.

  In the motor device 10 shown in FIG. 9, the yoke 14 has a substantially circular cut surface when cut in a direction perpendicular to the rotation center axis L. Six protruding protrusions 145a, 145b, 145c, 145d, 145e, and 145f are formed at equiangular intervals. These protrusions 145a, 145b, 145c, 145d, 145e, and 145f are closer to the outer peripheral surface of the rotor 12 than the peripheral portion. Here, when the arm portion 19 is in the intermediate position shown by the solid line in FIG. 9, the center position in the circumferential direction of the N pole and the center position in the circumferential direction of the S pole are respectively directed to the protrusions 145a and 145d. Is in a state. Therefore, in this embodiment, of the six protrusions 145a, 145b, 145c, 145d, 145e, and 145f, the two protrusions 145b and 145e function as a first magnetic stopper, and the two protrusions 145f and 145c It functions as a second magnetic stopper.

  Also in the yoke 14 of this embodiment, the through hole 15 for pulling out the arm portion 19 radially outward is formed over a predetermined angular range over the region where the projection 145e is formed CCW counterclockwise from the projection 145a. Has been. For this reason, when the rotor 12 rotates clockwise CW so that the arm part 19 moves from the intermediate position shown by the solid line in FIG. 9 to the position shown by the alternate long and short dash line in FIG. Since the portion abuts on one end 151 in the circumferential direction of the through hole 15, the one end 151 functions as a first mechanical stopper. On the other hand, when the rotor 12 is rotated counterclockwise CCW so that the arm 19 moves from the intermediate position shown by the solid line in FIG. 9 to the position shown by the two-dot chain line in FIG. Since the side end portion on the opposite side of 19 abuts on the other end portion 152 in the circumferential direction of the through hole 15, the other end portion 152 functions as a second mechanical stopper.

  Even in the shutter plate driving apparatus configured as described above, the rotor 12 is held by the magnetic stopper at the stop position defined by the mechanical stopper even when the coil 16 is not energized. Therefore, the shutter plate 3 can be held in the open position or the closed position without using a complicated mechanism.

  The through hole 15 has a slit shape elongated in the circumferential direction, and the opening width in the axial direction is only slightly larger than the thickness of the arm portion 19. For this reason, the yoke 14 is in a state of totally surrounding the rotor 14 including the portion where the through hole 15 is formed.

  In the yoke 14, the protrusions 145a and 145d are positioned at intermediate positions of the rotation angle range defined by the first and second mechanical stoppers (intermediate positions of the rotation angle ranges defined by the first and second magnetic stoppers). It functions as a third magnetic stopper for holding the rotor 12 in position).

[Other embodiments]
In addition, you may comprise a 3rd magnetic stopper in the form shown in FIG. Further, in this embodiment, the first mechanical stopper and the second mechanical stopper that define a rotation angle range narrower than the rotation angle range of the rotor defined by the first and second magnetic stoppers are provided. However, the first mechanical stopper and the second mechanical stopper may be omitted, and the rotor may be rotated within a rotation angle range defined by the first and second magnetic stoppers. In this case, the rotor is held by the magnetic attractive force at the center position in the circumferential direction of the N pole and S pole of the rotor closest to the first and second magnetic stoppers.

  In the first to fifth embodiments, when the magnetic stopper is configured by bringing the yoke close to the rotor, the central portion and the protrusion of the side are used. However, a part of the yoke is partially bent toward the rotor. Also good. Further, the N pole and S pole magnetizing positions of the permanent magnet 128 of the rotor 12 are optimal depending on the winding direction of the coil 16 or which part of the yoke is used to form the magnetic stopper. What is necessary is just to set and it is not limited to the said form.

  In the first to fifth embodiments, a through hole is formed in the yoke and its end is used as a mechanical stopper. However, the mechanical stopper may be configured by a member different from the yoke. In addition, for the mechanical stopper, a configuration in which an impact mitigating member for mitigating an impact is loaded, or a member having an impact mitigating property may be used as the mechanical stopper.

  In the first to fifth embodiments, the yoke is constituted by one component. However, a plurality of arcuate yoke pieces and flat yoke pieces may be arranged around the rotor.

  In the first to fifth embodiments, when the coil is disposed along the outer peripheral surface of the rotor and the end surfaces on both sides, the coil is disposed in parallel with the rotation center axis on the outer peripheral side of the rotor, but the bearing portion is avoided. The coil may be disposed obliquely with respect to the rotation center axis, for example, with an inclination of 45 ° or less. With this configuration, the dimension in the axial direction can be compressed. In addition, if the coil is disposed parallel to the rotation center axis on the outer peripheral side of the rotor and the coil is wound obliquely so as to avoid the bearing portion on the end surface of the rotor, the dimension in the axial direction can be compressed, and A reduction in rotational torque can be prevented.

  In the first to fifth embodiments, the motor device of the driving device for the shutter plate in the camera has been described as an example. However, the motor of the driving device that rotates the diaphragm plate, ND filter plate, and other movable members for the camera over a predetermined angle range. The present invention may be applied to an apparatus.

(A), (b) is the cross-sectional view and longitudinal cross-sectional view which respectively show the structure of the shutter board drive device which concerns on Embodiment 1 of this invention. (A), (b) is the cross-sectional view and longitudinal cross-sectional view which respectively show the structure of the motor apparatus (drive device) which comprises the drive part of the shutter plate drive device shown in FIG. It is a cross-sectional view which shows the structure of the motor apparatus (driving device) which concerns on the modification of Embodiment 1 of this invention. It is a cross-sectional view which shows the structure of the motor apparatus (drive device) which concerns on Embodiment 2 of this invention. It is a cross-sectional view which shows the structure of the motor apparatus (driving device) which concerns on the modification of Embodiment 2 of this invention. It is a cross-sectional view which shows the structure of the motor apparatus (drive device) which concerns on Embodiment 3 of this invention. It is a cross-sectional view which shows the structure of the motor apparatus (driving device) which concerns on the modification of Embodiment 3 of this invention. It is a cross-sectional view which shows the structure of the motor apparatus (drive device) which concerns on Embodiment 4 of this invention. It is a cross-sectional view which shows the structure of the motor apparatus (drive device) which concerns on Embodiment 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shutter plate drive device 3 Shutter plate 10 Motor device (drive device)
12 Rotor 15 Through-hole 14 Yoke 16 Coil 17 Coil frame 18 Second coil frame 19 Arm (swing member)
121 Rotating shafts 141a to 141f Corners 143a to 143f Sides 145a to 145f Projection 151 One side end 152 of the through hole The other side end of the through hole

Claims (7)

A rotor having different magnetic poles in the circumferential direction, a coil disposed along the outer peripheral surface of the rotor and end faces on both sides, and driving the rotor, and a yoke facing the outer peripheral surface of the rotor In the drive device provided,
The yoke is disposed so as to surround the rotor, and a magnetic force generated between the rotor and the rotor when the coil is not energized in a predetermined position in the circumferential direction is close to the rotor. A drive device comprising a first magnetic stopper and a second magnetic stopper that define a natural stop position of the rotor by a static attraction force.   2. The yoke according to claim 1, wherein the yoke is adjacent to the rotor between the first magnetic stopper and the second magnetic stopper in a circumferential direction and between the rotor when the coil is not energized. And a third magnetic stopper for defining a natural stop position of the rotor by a magnetic attraction force generated on the rotor. 3. The first rotation angle range according to claim 1, wherein the rotation angle range is narrower than the rotation angle range of the rotor which is in direct or indirect contact with the rotor and defined by the first and second magnetic stoppers. One mechanical stopper and a second mechanical stopper;
The rotor is held by the first magnetic stopper at a stop position defined by the first mechanical stopper in a non-energized state of the coil, and is defined by the second mechanical stopper. The driving apparatus is characterized in that the stop position is held by the second magnetic stopper. 4. The penetrating portion according to claim 3, wherein a swing member that outputs rotation of the rotor is extended outward from the rotor in a radial direction, and the yoke is extended to the outside of the yoke. Formed,
Each of the first and second mechanical stoppers includes a first end located on one side in the circumferential direction of the opening and a second end located on the other side. To drive. In any one of Claims 1 thru | or 4, when the said yoke is cut | disconnected in the direction orthogonal to the said rotating shaft, the cross-sectional shape is a substantially polygon,
The drive device according to claim 1, wherein the magnetic stopper is constituted by a portion corresponding to the side of the polygon. In any one of Claims 1 thru | or 4, the cross-sectional shape when the said yoke cut | disconnected in the direction orthogonal to the said rotating shaft is a substantially polygon,
The drive device according to claim 1, wherein the magnetic stopper is constituted by a protrusion protruding inward from a portion corresponding to the side of the polygon. In any one of Claim 1 thru | or 4, the cross-sectional shape when the said yoke cut | disconnected in the direction orthogonal to the said rotating shaft is substantially circular,
The drive device according to claim 1, wherein the magnetic stopper is formed by a protrusion protruding inward from the yoke.

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