JP5171067B2 - Driving device and light amount adjusting device - Google Patents

Description

  The present invention relates to a driving device suitable for a compact configuration and a light amount adjusting device having the driving device.

  The present applicant has proposed a drive device in the following light amount adjusting device disclosed in Patent Document 1 as a drive device that has a reduced diameter around the rotation axis and increased output.

  FIG. 8 shows an exploded perspective view of the drive device described in Patent Document 1, and FIG. 9 shows a side sectional view of the drive device described in Patent Document 1.

  8 and 9, the magnet 101 includes a permanent magnet that is divided into S and N poles by dividing the outer circumferential surface into two in the circumferential direction, and is rotatable about the rotation center. The coil 102 is disposed in the axial direction of the magnet 101.

  The stator 103 is excited by the coil 102, has a tooth-shaped outer magnetic pole portion 103 a and a cylindrical inner cylinder 103 b at the tip, and faces the outer peripheral surface and inner peripheral surface of the magnet 101. The auxiliary stator 104 is fixed to the inner cylinder 103 b of the stator 103 and forms an inner magnetic pole part together with the inner cylinder 103 b of the stator 103. The drive device in the light amount adjusting device is configured as described above.

  The magnet 101 includes shaft portions 101e and 101f so as to be rotatably held, and these are integrally formed. Further, the outer magnetic pole portion 103 a of the stator 103 faces the outer peripheral surface of the magnet 101 with a gap. The inner cylinder 103 b of the stator 103 is opposed to the inner peripheral surface of the magnet 101 with a gap.

  The drive device configured as described above reciprocally rotates the magnet 101 by switching the energizing direction of the coil 102 and switching the polarities of the outer magnetic pole portion 103a, the inner cylinder 103b, and the auxiliary stator 104. Further, the rotation of the reciprocating magnet 101 is restricted by the drive pin 101 d coming into contact with the guide groove 105 a provided in the base plate 105.

  In this drive device, the magnetic flux generated by energizing the coil 102 flows from the outer magnetic pole portion 103a to the opposing inner cylinder (inner magnetic pole portion) 103b or from the inner cylinder 103b to the opposing outer magnetic pole portion 103a. And it acts effectively on the magnet 101 located between the outer magnetic pole part 103a and the inner cylinder 103b.

  Further, the distance between the outer magnetic pole part 103a and the inner cylinder 103b is set to a distance corresponding to the thickness of the cylindrical magnet 101, the gap between the magnet 101 and the outer magnetic pole part 103a, and the gap between the magnet 101 and the inner cylinder 103b.

  Thus, the resistance of the magnetic circuit composed of the outer magnetic pole portion 103a and the inner cylinder 103b is made as small as possible. The smaller the resistance of the magnetic circuit, the more magnetic flux can be generated with less current, and the output is improved.

  On the other hand, as a small-sized, low-cost, high-output drive device and light amount adjusting device, the present applicant has proposed the following drive device and light amount adjusting device disclosed in Patent Document 2.

  The apparatus includes a first outer magnetic pole plate and a second outer magnetic pole plate, which are a pair of free ends arranged on both sides of the magnet, a connecting portion that connects the first outer magnetic pole plate and the second outer magnetic pole plate, And a protruding portion that protrudes from the connecting portion and faces the surface of the magnet at a predetermined interval.

  The first outer magnetic pole plate, the second outer magnetic pole plate, and the yoke integrally formed with the coupling portion are wound around the first outer magnetic pole plate at a position adjacent to the magnet in the axial direction of the rotor shaft. A rotated first coil. Further, a second coil wound around the second outer magnetic pole plate is provided at a position adjacent to the magnet in the axial direction of the rotor shaft.

  With this configuration, the cogging torque can be reduced and the length in the axial direction can be shortened, so that the rotation angle can be increased and stable while realizing miniaturization, cost reduction, and high output. Driving can be performed.

  Further, the following camera blade drive mechanism disclosed in Patent Document 3 has been proposed as a camera blade drive mechanism with good magnetic efficiency that is arranged at a peripheral position of the exposure opening.

  In the above-described mechanism, two yokes are arranged so as to sandwich a permanent magnet rotor magnetized with four poles, and each yoke has a magnetic pole portion whose end face is opposed to the circumferential surface of the rotor, and a rotating shaft of the rotor. And a bobbin around which a coil is wound is fitted in the winding part.

Each winding portion is coupled at its front end via a connecting yoke, and the overhanging portion is extended toward the rotor on the connecting yoke, and the overhanging portion is not opposed to the magnetic pole portion. Opposite the magnetic pole of the child. Magnetic efficiency can be improved by the overhanging portion acting on the magnetic pole of the rotor that is not opposed to the magnetic pole portion.
JP 2002-049076 A JP 2006-246556 A Japanese Patent Laid-Open No. 10-062836

  However, since the one proposed in Patent Document 1 has only one tooth-shaped outer magnetic pole portion 103a, the magnet 101 is attracted only in the direction in which the outer magnetic pole portion 103a faces when rotating, and the rotation is performed. The balance is bad and the loss is large.

  Here, if the magnet is divided and magnetized into four poles, the outer magnetic pole part can be made into two teeth and the rotation balance is improved, but since there are only two outer magnetic pole parts for the four poles, a high Output is difficult.

  The axial length of the driving device is determined by the length of the coil 102, the length of the magnet 101, and the thickness of the stator 103. The outer diameter of the driving device is the outer diameter of the inner cylinder 103b and the radial thickness of the coil 102. And the thickness of the outer magnetic pole portion 103a.

  Therefore, in order to increase the number of turns of the coil 102, there is no choice but to reduce the length of the magnet 101, reduce the thickness of the outer magnetic pole portion 103a, increase the length of the driving device, or increase the outer diameter of the driving device. . Here, if the length of the magnet 101 is reduced, there is a limit because the output is lowered, and if the thickness of the outer magnetic pole portion 103a is reduced, magnetic saturation occurs and the output is lowered.

  Therefore, the outer diameter has to be increased in order to obtain a drive device with a high output and a shorter axial length. In addition, a predetermined interval is required between the inner diameter of the magnet 101 and the auxiliary stator 104 facing the magnet 101, and managing it at the time of manufacturing increases the cost.

  Moreover, the cylindrical inner cylinder 103b and the outer magnetic pole part 103a are also required as the shape of the stator, and it is difficult to manufacture them integrally in terms of component manufacture. Furthermore, when they are assembled separately after being manufactured separately, the number of parts increases, resulting in an increase in cost.

  Further, in order to reduce the distance between the outer magnetic pole portion 103a and the auxiliary stator 104, there is a drawback that it is difficult to reduce the radial thickness of the cylindrical magnet 101 in terms of mechanical strength.

  In addition, what is proposed in Patent Document 2 above is that a yoke made of a soft magnetic material is integrally provided with a protrusion facing the magnet separately from the outer magnetic pole in order to adjust the cogging torque. Yes, the projection itself does not affect the magnetic flux generated by energization of the coil. Therefore, although it is effective for increasing the rotation angle, it cannot be expected that the output of the driving device is greatly improved.

  In addition, what is proposed in Patent Document 3 uses a total of three yokes, ie, two yokes and a connecting yoke, constituting the magnetic path, which increases the number of parts and increases the cost. In addition, because the end faces of the yoke face each other on both sides of the circumferential surface of the rotor, the size in the lateral direction (direction perpendicular to the rotation axis and the yoke faces) is inevitably increased, and the length of the magnetic path is increased. The magnetic efficiency is bad because it becomes longer.

  An object of the present invention is to provide a driving device and a light amount adjusting device that are low in cost, small in size, short in the axial direction, high in output, and capable of stable driving.

In order to achieve the above object, a driving device of the present invention is fixed to a cylindrical magnet that is divided into four in the circumferential direction and in which N and S poles are alternately magnetized, and an inner peripheral surface of the magnet. A rotor shaft made of a soft magnetic material ; limiting means for limiting a rotation range of the rotor shaft; a first coil disposed adjacent to the magnet in an axial direction of the rotor shaft; and an axial direction of the rotor shaft A second coil that is adjacent to the magnet and is disposed on substantially the same plane as the first coil and connected to the first coil, and is inserted into the inner peripheral surface of the first coil, A first outer magnetic pole portion facing the outer peripheral surface of the magnet and a second outer magnetic pole portion inserted into the inner peripheral surface of the second coil and facing the outer peripheral surface of the magnet are formed. Stator and the mug A third outer magnetic pole portion opposed to the outer peripheral surface of the magnet and a fourth outer magnetic pole portion opposed to the outer peripheral surface of the magnet are formed, facing the first stator with the magnet interposed therebetween. And the first outer magnetic pole portion is 180 degrees out of phase with the second outer magnetic pole portion with respect to the rotation center of the rotor shaft. The third outer magnetic pole part and the fourth outer magnetic pole part are in relation to the first outer magnetic pole part and the second outer magnetic pole part with respect to the rotation center of the rotor shaft. The first stator and the second stator are arranged so that the phases are different by 90 degrees, and the first outer magnetic pole portion and the second coil are energized by energizing the first coil and the second coil. In the second outer magnetic pole The same poles are respectively excited, and the third outer magnetic pole part and the fourth outer magnetic pole part have different poles from the poles excited by the first outer magnetic pole part and the second outer magnetic pole part, respectively. When the N pole is excited in the first outer magnetic pole part and the second outer magnetic pole part, the limiting means is excited so that the center of the S pole of the magnet is the center of the first outer magnetic pole part. And when the rotation range of the rotor shaft is limited before facing the center of the second outer magnetic pole portion, and the S pole is excited in the first outer magnetic pole portion and the second outer magnetic pole portion. The rotation range of the rotor shaft is limited before the center of the N pole of the magnet faces the center of the first outer magnetic pole part and the center of the second outer magnetic pole part, respectively .

  A light amount adjusting device according to a fourth aspect is connected to the driving device according to any one of the first to third aspects, the ground plate having an opening through which light passes, and the opening according to forward and reverse rotation of the magnet. And a light amount adjusting member for increasing or decreasing the area of the portion.

  According to the present invention, the cost is low, the size is small, the axial length is short, the output can be increased, and stable driving is possible.

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

  FIG. 1 is an exploded perspective view of a drive device according to an embodiment of the present invention, FIG. 2 is an assembled state diagram without a cover of the drive device of FIG. 1, and FIG. It is sectional drawing in the surface which passes along a rotor axis | shaft and is parallel to an axial direction. 4 is a cross-sectional view taken along a plane that passes through the rotor shaft of the drive device of FIG. 1 and is parallel to the axial direction and perpendicular to the cross section of FIG.

  In these drawings, a first stator 1 made of a soft magnetic material is composed of a first outer magnetic pole portion 1a and a second outer magnetic pole portion 1b each having a free end shape, and a bottom portion 1c that connects them. It has a structure that can be press-molded. In addition, a hole 1d is provided in the bottom 1c. The first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are formed in a comb-teeth shape extending in the same direction and in the direction parallel to the shaft 8 described later.

  The first coil 2 is formed by winding a conductive wire, the second coil 3 is formed by winding a conductive wire, and the cover 4 is formed by winding the first coil 2 and the second coil 3. It has a bobbin part.

  The first coil 2 is fixed so that the first outer magnetic pole portion 1a is disposed on the inner periphery of the first coil 2 while being wound around the bobbin portion of the cover 4. Then, by energizing the first coil 2, the first outer magnetic pole portion 1a is excited.

  Similarly, the 2nd coil 3 is fixed so that the 2nd outer side magnetic pole part 1b may be arrange | positioned in the inner periphery in the state wound around the bobbin part of the cover 4. As shown in FIG. Then, by energizing the second coil 3, the second outer magnetic pole portion 1b is excited.

  Since the first coil 2 and the second coil 3 are arranged adjacent to each other on the plane of the bottom 1d of the first stator 1, the axial length of the drive device can be shortened. In addition, since the first coil 2 and the second coil 3 are connected in series and arranged adjacent to each other, the total number of turns of the coil is increased, and the output in the axial direction of the drive device is kept short. Improvements can be made.

  The first coil 2 and the second coil 3 are connected in series so that the winding directions are the same. That is, when the first coil 2 and the second coil 3 connected in series are energized, the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are excited to the same pole.

  Without providing separate bobbins for the first coil 2 and the second coil 3, the cost can be reduced by connecting them together and integrating them with the cover, and wiring in series Becomes easy. Although the first coil 2 and the second coil 3 are connected in series, they may be connected in parallel.

  When driving at a constant voltage, the output increases in parallel connection, but the current consumption increases. In series connection, current consumption can be reduced compared to parallel connection (when the same coil is used).

  The conductive terminal pin 5 is embedded in the cover 4 and the coil ends of the first coil 2 and the second coil 3 are connected. A cylindrical magnet 6 made of a permanent magnet has its outer peripheral surface divided into four in the circumferential direction, and S and N poles are alternately magnetized.

  In addition, the inner peripheral surface of the magnet 6 has a weak magnetization distribution compared to the outer peripheral surface, or is not magnetized at all, or is opposite to the outer peripheral surface, that is, when the outer peripheral surface is an S pole. The inner peripheral surface of the range is one that is magnetized to the N pole.

  The core 7 is made of a soft magnetic material, and the shaft 8 is made of a soft magnetic material that is fixed to the shaft center of the core 7 by press fitting or the like. The outer peripheral surface of the first cylindrical portion 7a of the core 7 and the inner peripheral surface 6a of the magnet 6 are closely fixed by adhesion or the like.

  A rotor shaft is formed by the core 7 and the shaft 8, and the position of the rotor shaft in the axial direction is restricted by the first bearing 11 and the second bearing 12 with a predetermined gap (FIG. 3). reference). The second coil 3 is adjacent to the magnet 6 in the axial direction of the rotor shaft and is disposed on substantially the same plane as the first coil 2 and connected to the first coil 2.

  In the present embodiment, the core 7 and the shaft 8 are separately fixed, but these two parts may be integrally formed. By using a separate body, the shaft 8 can be made of a material such as SUS having high strength and excellent wear resistance. The core 7 can be made of a soft magnetic material such as SUY having good magnetic efficiency.

  Moreover, by forming integrally, the cost reduction by reduction of a number of parts can be aimed at, and the coaxial positional accuracy of the core 7 and the axis | shaft 8 improves.

  By fixing the inner peripheral surface 6a of the magnet 6 to the first columnar portion 7a of the core 7, there is no concern in terms of strength even if the thickness of the magnet 6 in the radial direction is very thin. Both ends of the shaft 8 fixed to the core 7 are rotatably supported by a first bearing 11 and a second bearing 12 which will be described later.

  In that case, the 2nd cylindrical part 7b of the core 7 is arrange | positioned adjacently between the 1st coil 2 and the 2nd coil 3, as shown in FIG. Further, the first cylindrical portion 7a of the core 7 and an inner peripheral surface 9a of the lever 9 described later are firmly fixed by adhesion or the like. That is, as shown in FIG. 3, the magnet 6 and the lever 9 are fixed to the first cylindrical portion 7a of the core 7 so as to be adjacent to each other in the axial direction.

  The lever 9 is fixed to the core 7 by bonding or the like, and can be rotated integrally. The lever 9 is provided with a drive pin 9b at one end thereof.

  The second stator 10 made of a soft magnetic material includes a third outer magnetic pole portion 10a and a fourth outer magnetic pole portion 10b each having a free end shape, and a bottom portion 10c connecting them, and can be press-molded integrally. It has a structure. Moreover, a hole is provided in the bottom 10c. The third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b are formed in a comb-teeth shape extending in the same direction as the shaft 8 and in the opposite direction to the outer magnetic pole portion of the first stator 1.

  The first bearing 11 made of a soft magnetic material is fixed to the hole 1 d of the first stator 1 by press fitting or the like, and the shaft hole 11 a rotatably supports one end of the shaft 8. The second bearing 12 made of a soft magnetic material is fixed to the hole portion of the second stator 10 by press fitting or the like, and the shaft hole portion 12a rotatably supports the other end of the shaft 8.

  The first stator 1 and the second stator 10 are positioned and fixed to the cover 4. As shown in FIG. 3, the lever 9 extends outward from an opening provided in the cover 4. As a result, the lever 9 acts as an output means while being fixed to the magnet 6. That is, the axial length of the entire drive device including the output means is shortened.

  The first stator 1 and the second stator 10 rotatably support a rotor composed of a magnet 6, a core 7, and a shaft 8 while being positioned and fixed to the cover 4.

  In this state, the magnet 6 has a predetermined gap between the outer peripheral surface of the first outer magnetic pole part 1a and the second outer magnetic pole part 1b as shown in FIG. 3, and as shown in FIG. The outer peripheral surface has a predetermined gap from the third outer magnetic pole part 10a and the fourth outer magnetic pole part 10b.

  The magnet 6 is disposed adjacent to the first coil 2 and the second coil 3 in the axial direction, and the first coil 2 and the second coil 3 are planes perpendicular to the axial direction. Since they are adjacent to each other, it is possible to provide a driving device having a short axial length.

  Further, the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are configured in a comb-teeth shape extending in a direction parallel to the shaft 8, and the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 1b. The magnetic pole portion 10b is also configured in a comb-teeth shape extending in a direction parallel to the shaft 8. For this reason, the outermost diameter in the direction perpendicular to the shaft 8 of the drive device can be minimized.

  For example, when the outer magnetic pole portion is formed of a yoke plate extending in the radial direction of the magnet (direction perpendicular to the axis) as in Patent Document 3, the coil is disposed adjacent to the radial direction of the magnet. As a result, even if the length in the axial direction is short, the outermost diameter in the direction perpendicular to the axis of the drive device becomes large.

  On the other hand, the outermost diameter in the direction perpendicular to the axis of the driving device according to the present embodiment has the magnet 6, the thickness of the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b, and the first coil. 2 and substantially determined by the winding width of the second coil 3 (see FIG. 3).

  In the first stator 1, the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are integrally formed with the bottom portion 1c. For this reason, the mutual error between the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b is reduced.

  In the second stator 10, the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b are integrally formed with the bottom portion 10c. For this reason, the mutual error between the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b is reduced. Therefore, the variation in the performance of the drive device due to assembly can be minimized.

  Further, the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are configured in a comb-teeth shape extending in a direction parallel to the shaft 8, and the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 1b. The magnetic pole portion 10b is also configured in a comb-teeth shape extending in a direction parallel to the shaft 8.

  Therefore, the coil unit composed of the first coil 2 and the second coil 3 wound around the cover 4 and the rotor composed of the magnet 6, the core 7 and the shaft 8 are all in one direction (from the upper direction to the lower direction in FIG. 1). The assembly workability is good.

  The phase in which the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are opposed to the magnet 6 and the phase in which the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b are opposed to the magnet 6 are attached to the magnet. When the number of magnetic poles is n, there is a shift of about 360 / n degrees. In this embodiment, since n = 4, it is shifted by 90 degrees.

  This is because when the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are opposed to, for example, the N pole, the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b are opposed to the S pole. It will be.

  The first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are arranged to face the outer peripheral surface of the magnet 6 with a predetermined gap.

  The portion of the first cylindrical portion 7a facing the first outer magnetic pole portion 1a, the portion of the second cylindrical portion 7b adjacent to the outer periphery of the first coil 2, the shaft 8 and the first bearing 11 are the first. Are formed.

  Similarly, the portion of the first cylindrical portion 7a that faces the second outer magnetic pole portion 1b, the portion of the second cylindrical portion 7b adjacent to the outer periphery of the second coil 3, the shaft 8 and the second bearing 12 Two inner magnetic pole portions are formed.

  When the first coil 2 is energized, the first outer magnetic pole portion 1a and the first inner magnetic pole portion are excited, and a magnetic flux crossing the magnet 6 is generated between the magnetic poles. Act on. At that time, the first outer magnetic pole portion 1a and the first inner magnetic pole portion are excited to opposite poles.

  Similarly, when the second coil 3 is energized, the second outer magnetic pole portion 1b and the second inner magnetic pole portion are excited, and a magnetic flux crossing the magnet 6 is generated between the magnetic poles. 6 acts. At that time, the second outer magnetic pole portion 1b and the second inner magnetic pole portion are excited to opposite poles.

  The magnetic circuit passing from the first outer magnetic pole portion 1a through the magnet 6 and passing through the first inner magnetic pole portion passes through the first magnetic circuit, and the second outer magnetic pole portion 1b passes through the magnet 6 to the second magnetic circuit. A magnetic circuit passing through the inner magnetic pole portion of the second magnetic circuit is defined as a second magnetic circuit.

  The second stator 10 is magnetically coupled to the first stator 1 via the second bearing 12, the core 7 and the shaft 8, and the first bearing 11. The first outer magnetic pole portion 1a, the third outer magnetic pole portion 10a, and the fourth outer magnetic pole portion 10b are disposed adjacent to each other. Further, the second outer magnetic pole portion 1b, the third outer magnetic pole portion 10a, and the fourth outer magnetic pole portion 10b are disposed adjacent to each other (see FIG. 5 described later).

  As a result, when the first coil 3 is energized, the first outer magnetic pole portion 1a, the third outer magnetic pole portion 10a, and the fourth outer magnetic pole portion 10b are excited to the opposite poles, respectively. The magnetic flux emitted from the magnetic pole part 1a goes to the third outer magnetic pole part 10a and the fourth outer magnetic pole part 10b.

  Further, when the second coil 4 is energized, the second outer magnetic pole portion 1b, the third outer magnetic pole portion 10a, and the fourth outer magnetic pole portion 10b are excited to opposite poles, respectively, and the second outer magnetic pole portion is excited. The magnetic flux emitted from the portion 1b is directed to the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b.

  After passing through the air from the first outer magnetic pole portion 1a to the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b, the second bearing 12, the core 7 and the shaft 8, and the first bearing. A magnetic circuit passing through 11 is a third magnetic circuit.

  Further, after passing through the air from the second outer magnetic pole portion 1b to the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b, the second bearing 12, the core 7 and the shaft 8, and the first bearing. A magnetic circuit passing through 11 is a fourth magnetic circuit.

  Since the first coil 2 and the second coil 3 are connected in series and in the same winding direction, the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are simultaneously Excited to the same pole. Further, the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b are simultaneously excited to have different poles from the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b.

  As described above, the magnet 6 can be very thin in the radial direction of the cylindrical shape, and the first columnar portion 7 a that forms the inner magnetic pole portion facing the inner peripheral surface of the magnet 6 and the magnet 6 can be formed. There is no need to provide a gap between the inner peripheral surface.

  Therefore, the distance between the first outer magnetic pole part 1a and the first cylindrical part 7a and the distance between the second outer magnetic pole part 1b and the first cylindrical part 7a can be made extremely small. Therefore, the magnetic resistance of the first magnetic circuit and the second magnetic circuit can be reduced, and the output of the driving device can be increased.

  Moreover, as shown in FIG. 3, since the inner diameter part of the magnet 6 is filled with the core 7, compared with what was proposed by the said patent document 1, the mechanical strength of a magnet becomes large.

  In addition, the core 7 acts as a so-called back metal that reduces the magnetic resistance between the S pole and N pole appearing on the inner diameter part of the magnet 6, so that the permeance coefficient of the magnetic circuit is set high. Even when used in high-temperature environments, there is little magnetic deterioration due to demagnetization.

  Furthermore, what is proposed in the above-mentioned Patent Document 1 is that it is necessary to assemble with keeping the gap between the outer diameter portion and the outer magnetic pole portion of the magnet with high accuracy, and the inner magnetic pole portion located at the position facing the inner diameter portion of the magnet. Must be arranged with a predetermined gap with respect to the magnet.

  For this reason, when the dispersion | variation in component precision and assembly precision are bad, this clearance gap cannot be ensured, but there is a high possibility that a defect such as the inner magnetic pole portion contacting the magnet will occur.

  On the other hand, in the present embodiment, it is only necessary to manage the gap only on the outer diameter side of the magnet 6, so that the assembly becomes easy.

  Further, in Patent Document 1, the inner magnetic pole portion must be configured not to contact the portion connecting the magnet and the shaft, thereby sufficiently increasing the axial length of the inner magnetic pole portion and the magnet facing each other. Can not do it.

  On the other hand, in the present embodiment, since the core 7 also serves as the inner magnetic pole portion, it is possible to secure a sufficiently long axial length in which the inner magnetic pole portion and the magnet 6 face each other. As a result, the first outer magnetic pole portion 1a, the second outer magnetic pole portion 1b, and the magnet 6 can be used effectively, and the output of the driving device can be increased.

  As described above, the drive device according to the present embodiment is provided with the second stator 10 in addition to the first stator 1, and thus the above four magnetic circuits are configured. Can be generated. As a result, it is possible to increase the output of the driving device, reduce power consumption, and reduce the coil size.

  FIG. 5 is a top view showing the positional relationship between the magnet 6 and the first outer magnetic pole portion 1a, the second outer magnetic pole portion 1b, the third outer magnetic pole portion 10a, and the fourth outer magnetic pole portion 10b. The cover 4 and the lever 9 are omitted for easy understanding from the driving device shown in FIGS. 1 to 4.

  As can be seen from FIG. 5, the magnet 6 has a magnetized portion in which the outer peripheral surface is divided into four in the circumferential direction and is magnetized alternately in the S and N poles.

  Here, the positional relationship between the magnet 6 and the first outer magnetic pole portion 1a, the second outer magnetic pole portion 1b, the third outer magnetic pole portion 10a, and the fourth outer magnetic pole portion 10b will be described.

  The first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are disposed at positions that are 180 degrees out of phase with respect to the rotation center of the magnet 6.

  Therefore, when the center of the first outer magnetic pole portion 1 a faces the N-pole center of the magnet 6, the center of the second outer magnetic pole portion 1 b also faces the N-pole center of the magnet 6. Further, when the center of the first outer magnetic pole portion 1 a faces the center of the S pole of the magnet 6, the center of the second outer magnetic pole portion 1 b also faces the center of the S pole of the magnet 6.

  Further, the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b are 90 degrees out of phase with the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b on the basis of the rotation center of the magnet 6. It is arranged at a shifted position.

  Therefore, when the center of the first outer magnetic pole part 1a and the center of the second outer magnetic pole part 1b are opposed to the center of the N pole of the magnet 6, the center of the third outer magnetic pole part 10a and the fourth The center of the outer magnetic pole part 10 b faces the center of the S pole of the magnet 6.

  When the center of the first outer magnetic pole portion 1a and the center of the second outer magnetic pole portion 1b are opposite to the center of the S pole of the magnet 6, the center of the third outer magnetic pole portion 10a and the fourth The center of the outer magnetic pole part 10 b faces the center of the N pole of the magnet 6.

  The first coil 2 and the second coil 3 have the same winding direction and are wired in series.

  Therefore, by energizing the first coil 2 and the second coil 3, the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are excited to the same pole. Further, both the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b are excited to poles different from those of the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b.

  That is, the magnetic force generated by energizing the first coil 2 and the second coil 3 is a force for rotating the magnet 6 in the same direction. In the driving device disclosed in Patent Document 1, the outer magnetic pole portion is ½ of the number of magnetized magnetic poles (in the embodiment of Patent Document 1, there are two magnets and one outer magnetic pole portion), so that the rotation balance is poor. It was a thing.

  However, the drive device of the present embodiment can be configured so that the magnet 6 has four poles and the outer magnetic pole portions have four, and the rotation balance is good and the output is high.

  Next, the operation of the drive device according to the embodiment of the present invention will be described with reference to FIGS.

  FIG. 5 shows a state of the driving device in which the first coil 2 and the second coil 3 are energized and excited so that the N pole and the S pole are in the following states. Specifically, the first outer magnetic pole portion 1a is an S pole, the first inner magnetic pole portion is an N pole, the second outer magnetic pole portion 1b is an S pole, and the second inner magnetic pole portion is an N pole. The third outer magnetic pole portion 10a is an N pole, and the fourth outer magnetic pole portion 10b is an N pole.

  The magnet 6 is stopped from rotating in the state shown in FIG. 5 because the drive pin 9b of the lever 9 that rotates integrally comes into contact with one end of a long hole 13b of the base plate 13 described later. In this state, when the magnet 6 is energized to the first coil 2 and the second coil 3, the center of the first outer magnetic pole portion 1 a coincides with the center of the magnetized portion of the magnet 6 (the center of the N pole). Thus, a clockwise rotational force in the figure is generated. Further, a clockwise rotating force is generated in the drawing so that the center of the second outer magnetic pole portion 1b and the center of the magnetized portion of the magnet 6 (the center of the N pole) coincide.

  Further, a clockwise rotational force is generated in the figure so that the center of the third outer magnetic pole portion 10a and the center of the magnetized portion of the magnet 6 (the center of the S pole) coincide. Further, a clockwise rotational force is generated in the figure so that the center of the fourth outer magnetic pole portion 10b and the center of the magnetized portion of the magnet 6 (the center of the S pole) coincide.

  Further, when the energization of the first coil 2 and the second coil 3 is stopped, the magnet 6 has the first outer magnetic pole portion 1a, the second outer magnetic pole portion 1b, the third outer magnetic pole portion 10a, and the fourth. The outer magnetic pole portion 10b is held at this position by the cogging force generated.

  When the energization direction to the first coil 2 and the second coil 3 is reversed from the state of FIG. 5 and is excited as follows, the magnet 6 rotates counterclockwise. That is, the first outer magnetic pole portion 1a is an N pole, the first inner magnetic pole portion is an S pole, the second outer magnetic pole portion 1b is an N pole, the second inner magnetic pole portion is an S pole, and the third The outer magnetic pole portion 10a is the S pole, and the fourth outer magnetic pole portion 10b is the S pole.

  The drive pin 9b of the lever 9 that rotates integrally with the magnet 6 comes into contact with the other end of a long hole 13b of the base plate 13, which will be described later, and the rotation is stopped in the state of FIG.

  In this state, while the magnet 6 is energized to the first coil 2 and the second coil 3, the center of the first outer magnetic pole portion 1 a coincides with the center of the magnetized portion of the magnet 6 (the center of the S pole). Thus, a counterclockwise rotational force is generated in the figure.

  Further, a counterclockwise rotational force is generated so that the center of the second outer magnetic pole portion 1b coincides with the center of the magnetized portion of the magnet 6 (the center of the S pole). Further, a counterclockwise rotational force is generated so that the center of the third outer magnetic pole portion 10a and the center of the magnetized portion of the magnet 6 (the center of the N pole) coincide. Further, a counterclockwise rotational force is generated in the drawing so that the center of the fourth outer magnetic pole portion 10b coincides with the center of the magnetized portion of the magnet 6 (the center of the N pole).

  Further, when the energization of the first coil 2 and the second coil 3 is stopped, the magnet 6 has the first outer magnetic pole portion 1a, the second outer magnetic pole portion 1b, the third outer magnetic pole portion 10a, and the fourth. The outer magnetic pole portion 10b is held at this position by the cogging force generated.

  As described above, by switching the energization direction to the first coil 2 and the second coil 3, the magnet 6 reciprocates and rotates within the range determined by the stopper (the long hole 13b of the base plate 13) together with the lever 9. It will be.

  FIG. 7 is an exploded perspective view of a shutter device using the driving device M of FIG.

  In FIG. 7, the driving device M is attached to the ground plate 13 having an opening 13a formed at the center by adhesion or the like. At that time, the drive pin 9 b of the lever 9 in the drive device M is inserted into the long hole 13 b provided in the main plate 13.

  The magnet 6 can rotate from a position where the drive pin 9b of the lever 9 contacts one end of the long hole 13b to a position where it contacts the other end. Further, the base plate 13 is integrally formed with protrusions 13c and 13d protruding in the same direction as the drive pin 9b.

  The circular hole 14a of the blade 14 is rotatably fitted to the protrusion 13d of the base plate 13, and the long hole 14b of the blade 14 is slidably fitted to the drive pin 9b of the lever 9. Further, the round hole 15 a of the blade 15 is rotatably fitted to the protrusion 13 c of the base plate 13, and the long hole 15 b of the blade 15 is slidably fitted to the drive pin 9 b of the lever 9.

  The blade retainer 16 having an opening 16a formed at the center is fixed to the base plate 13 with the blade 14 and the blade 15 sandwiched therebetween with a predetermined gap, and serves as an axial receiver for the blade 14 and the blade 15.

  The rotation of the magnet 6 causes the blade 14 to rotate about the round hole 14a with the elongated hole 14b being pushed by the drive pin 9b of the lever 9, and the blade 15 is pushed to the round hole with the elongated hole 15b being pushed to the drive pin 9b of the lever 9. Rotate around 15a. Thereby, it is comprised so that the passage light quantity of the opening part 13a of the ground plane 13 may be controlled.

  Since the driving device M has a short length in the axial direction, the driving device M can be a shutter device with little protrusion in the optical axis direction that does not interfere with other lenses and structures. In addition, the shutter speed can be increased because the output is small but the output is high.

  In the above embodiment, the driving device M is used as an actuator for driving the shutter blades. However, it can also be used for other applications, such as turning an aperture device, a cam cylinder for driving a lens, etc., to two positions, and is said to have a high output, a small outer diameter, and a short axial length. It becomes useful as a driving device having advantages.

  For example, the drive pin 9b of the lever 9 is connected to a cam cylinder (not shown) that can rotate around the optical axis, and is useful even in the following configuration.

  That is, when the lever 9 is rotated, the cam cylinder is rotated, and the cam cylinder is provided with two cam portions having different heights in the optical axis direction, and is not shown in the figure. The lens holder to which the lens is fixed is configured to move in the optical axis direction by rotating the cam cylinder.

Here, the effects in the above-described embodiment will be collectively listed below.
1) If the core 7 and the shaft 8 fixed to the inner peripheral surface of the magnet 6 are called inner magnetic pole portions, the magnetic flux generated by the first coil 2 is the first outer magnetic pole portion facing the outer peripheral surface of the magnet 6. It passes between 1a and the inner magnetic pole part.

  Accordingly, the magnetic flux effectively acts on the magnet 6, and similarly, the magnetic flux generated by the second coil 3 passes between the second outer magnetic pole portion 1 b and the inner magnetic pole portion facing the outer peripheral surface of the magnet 6. Therefore, it acts on the magnet 6 effectively.

As a result, it is possible to improve the output of the driving device. Further, the magnetic flux generated by the first coil 2 and the second coil 3 also acts on the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b. As a result, the output of the drive device is greatly improved as compared with the drive device proposed in Patent Document 2.
2) Since the magnetic pole part is also composed of four teeth with respect to the four magnet poles, the rotation balance is better than that of the driving device proposed in Patent Document 1.
3) Since the magnetic flux generated by the energization of the first coil 2 and the magnetic flux generated by the energization of the second coil 3 simultaneously act on the magnet 6, the total number of driving devices can be doubled without increasing the number of turns of one coil. The number of turns is obtained. Therefore, it is possible to provide a high-output drive device while reducing the axial length without increasing the outer diameter.
4) Since the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b are formed in a comb-teeth shape extending in the same direction as the axial direction of the rotor shaft, Compared with the drive mechanism, the dimension in the direction perpendicular to the axial direction can be reduced. Further, the coil can be easily assembled.
5) The first coil 2 and the second coil 3 are wired in series, or the first coil 2 and the second coil 3 are wired in parallel, so that the first coil 2 In addition, only one circuit for energizing the second coil 3 is required, and the cost can be reduced.

  As is apparent from the above, it is possible to provide a drive device that is small in size, short in the axial direction, low in cost, high in output, and has a good rotational balance. Further, by using the driving device for a light amount adjusting device such as a shutter device or a lens driving device, it is possible to increase the operating speed of the shutter blades or the lens barrel while achieving miniaturization and cost reduction.

  In the above embodiment, the core 7 and the shaft 8 in FIGS. 3 to 6 correspond to the rotor shaft of the present invention, and the first blade 14 and the second blade 15 in FIG. 7 correspond to the light quantity adjusting member of the present invention. To do. The light amount adjusting member increases or decreases the area of the base plate having an opening through which light passes and the opening (elongate hole 13 b) of the base plate 13 in accordance with forward and reverse rotation of the magnet 6.

  The present invention is not limited to the present embodiment, and it is needless to say that any configuration may be used as long as it can achieve the functions indicated in the claims or the functions of the embodiment.

  For example, in the present embodiment, the second stator 10 is configured to include the third outer magnetic pole portion 10a and the fourth outer magnetic pole portion 10b, but may be configured to include only the third outer magnetic pole portion 10b. . In this case, the output is somewhat lower than that provided with two outer magnetic pole portions, but the size in the width direction (vertical direction in FIG. 5) of the drive device can be further reduced.

  In the present embodiment, the number of magnetic poles of the magnet 6 is four. However, when the number of poles is six or more, the first outer magnetic pole between the first outer magnetic pole portion 1a and the second outer magnetic pole portion 1b. The number of poles on the outer peripheral surface of the magnet 6 where the part 1a and the second outer magnetic pole part 1b are not opposed increases. Therefore, it is desirable that the outer magnetic pole part of the second stator 10 includes four parts on both sides of the first outer magnetic pole part 1a and on both sides of the second outer magnetic pole part 1b.

  The present invention can be applied to various devices in which it is desired to increase the drive torque of a drive device that is driven to reciprocate within a predetermined range.

It is a disassembled perspective view of the drive device concerning an embodiment of the invention. FIG. 2 is an assembled state diagram in which a cover of the drive device of FIG. 1 is omitted. FIG. 2 is a longitudinal sectional view of a plane passing through a coil in parallel with the rotor axis direction around the rotor axis of the drive device of FIG. 1. FIG. 4 is a longitudinal sectional view of a plane perpendicular to the rotor axis direction and perpendicular to the section of FIG. 3 around the rotor axis of the drive device of FIG. FIG. 2 is a cross-sectional view taken along a plane that passes through the magnet perpendicular to the rotor axial direction and showing the phase relationship between the magnet and the outer magnetic pole portion of the drive device of FIG. 1. It is a top view which shows the state which switched the coil electricity supply from the state of FIG. 5, and rotated the magnet. It is a disassembled perspective view of the shutter apparatus using the drive device of FIG. It is a disassembled perspective view which shows one structural example of the conventional drive device. It is sectional drawing in a surface parallel to the rotor axial direction of the drive device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st stator 1a 1st outer magnetic pole part 1b 2nd outer magnetic pole part 2 1st coil 3 2nd coil 4 Cover 5 Terminal pin 6 Magnet 7 Core 8 Shaft 9 Lever 10 2nd stator 10a 3rd Outer magnetic pole part 10b Fourth outer magnetic pole part 11 First bearing 12 Second bearing

Claims (4)

A cylindrical magnet divided into four in the circumferential direction and alternately magnetized with N and S poles ;
A rotor shaft made of a soft magnetic material fixed to the inner peripheral surface of the magnet;
Limiting means for limiting the rotation range of the rotor shaft;
A first coil disposed adjacent to the magnet in the axial direction of the rotor shaft;
A second coil that is adjacent to the magnet in the axial direction of the rotor shaft and is disposed on substantially the same plane as the first coil and connected to the first coil;
A first outer magnetic pole portion that is inserted into the inner peripheral surface of the first coil and faces the outer peripheral surface of the magnet, and is inserted into the inner peripheral surface of the second coil and faces the outer peripheral surface of the magnet. A first stator formed with a second outer magnetic pole portion;
A third outer magnetic pole portion facing the outer peripheral surface of the magnet and a fourth outer magnetic pole portion facing the outer peripheral surface of the magnet are formed, facing the first stator with the magnet interposed therebetween. A second stator arranged,
The first outer magnetic pole portion forms the first stator so that the phase is 180 degrees different from the second outer magnetic pole portion with respect to the rotation center of the rotor shaft.
The third outer magnetic pole part and the fourth outer magnetic pole part are each 90 degrees out of phase with respect to the first outer magnetic pole part and the second outer magnetic pole part with respect to the rotation center of the rotor shaft. And arranging the first stator and the second stator,
By energizing the first coil and the second coil, the same poles are excited in the first outer magnetic pole part and the second outer magnetic pole part, respectively. In the fourth outer magnetic pole part, poles different from the poles excited in the first outer magnetic pole part and the second outer magnetic pole part are respectively excited,
When the N pole is excited in the first outer magnetic pole part and the second outer magnetic pole part, the limiting means is configured such that the S pole center of the magnet is the center of the first outer magnetic pole part and the first outer magnetic pole part. The rotation range of the rotor shaft is limited before facing the center of each of the two outer magnetic pole portions, and when the S pole is excited in the first outer magnetic pole portion and the second outer magnetic pole portion, the magnet And a rotation range of the rotor shaft is limited before the center of the N pole faces the center of the first outer magnetic pole part and the center of the second outer magnetic pole part, respectively .   The drive device according to claim 1, wherein the first coil and the second coil are connected in series.   The drive device according to claim 1, wherein the connection between the first coil and the second coil is a parallel connection.   A ground plane having an opening through which light passes, coupled to the drive device according to any one of claims 1 to 3, and a light amount adjusting member for increasing or decreasing an area of the opening in accordance with forward and reverse rotation of the magnet. A light amount adjusting device comprising:

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