JP2006227062A - Reciprocating drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the capacity, cost, and size of a power source in a reciprocating drive device used to reciprocate a movable component. <P>SOLUTION: An inner tubular body 15 has three drive magnets 21 in corresponding holes 19 disposed in the periphery of the inner tubular body 15 so as to project from the periphery. An outer tubular body 25 has three arcuate guide pieces 27 along a hollow section 25a annularly. Each guide piece 27 of the outer tubular body 25 has a holding hole 35. An insertion groove 31 is formed along the periphery of each guide piece 27. Each of circuit boards 39 has insertion holes 43 at prescribed intervals, a coil 41 disposed on one side and a yoke 47 disposed on the one side and the circuit boards 39 are inserted in insertion grooves 31 of the outer tubular body 25. The outer tubular body 25 has spherical bodies 51 and magnets 53 inserted from through-holes 37 communicating with the holding hole 35. Thus, the spherical bodies 51 are held in the holding hole 35 while kept attracted by the magnets 53. Each spherical body 51 is disposed in point-contact with the periphery of the tubular body 15 inserted in the hollow section 25a of the outer tubular body 25. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an advancing / retreating drive device, and for example, relates to an improvement of an advancing / retreating drive device for moving a movable part such as a lens in a small optical device such as a mobile phone, a CCD camera, and a handy video camera.

  In recent years, for example, mobile phones equipped with an electronic camera function have been widely used, and the electronic camera function installed has an autofocus, zoom, macro function, and the like.

  Such an electronic camera function requires a lens driving device in order to realize the function, and various forward / backward driving devices have been proposed so far. For example, there is a configuration shown in FIG.

  That is, a sliding body as a bearing in which a ring-shaped magnet 5 unipolarly magnetized in the radial direction is arranged on the outer periphery of the hollow shaft 3 that supports the lens 1 on the inner side, and is fitted to close both ends of the cylindrical case 7. 9 and 11, the hollow shaft 3 is pivotally supported, and the coil 13 is arranged between the sliding bodies 9 and 11 so as to face the magnet 5 on the inner wall of the case 7. Japanese Patent Laid-Open No. 10-150759 (Patent Document 1) is of this type.

In the configuration shown in FIG. 11, by changing the direction and strength of the drive current flowing in the coil 13, axial stress is generated in the magnet 5 unipolarly magnetized in the radial direction, and the sliding bodies 9, 11 are affected. The hollow shaft 3 that is slidably supported is moved forward and backward in the direction of the arrow t, and functions such as autofocus, zoom, and macro function are realized.
JP-A-10-150759

  However, in the above-described conventional configuration, the hollow shaft 3 for moving the lens 1 as the movable part forward and backward is inserted so as to come into contact with the through holes of the sliding bodies 9 and 11, and is supported in a slidable state. In order to move the hollow shaft 3 forward and backward with respect to the case 7, a certain level of stress is required, and it is difficult to reduce the load.

  For this reason, it is necessary to pass a driving current of a certain value or more to the coil 13 and the driving power cannot be reduced, the coil 13 having a certain number of windings or more, or the magnet 5 of the hollow shaft 3 It was necessary to increase the magnetizing strength, which was likely to be an obstacle to cost reduction and miniaturization.

  The present invention has been made under such circumstances, and it is possible to provide a forward / backward drive device capable of moving and moving a movable part with a small load, reducing the capacity of the power battery, and further reducing the cost and size. With the goal.

  In order to solve such a problem, the present invention provides an outer cylinder, an inner cylinder inserted in a hollow portion of the outer cylinder with a slight gap, and one of the outer cylinder and the inner cylinder. And a drive source that moves relatively back and forth in the axial direction of the hollow portion, and is rotatably supported on the inner wall side of the outer cylindrical body or the outer peripheral side of the inner cylindrical body, and on the outer periphery or the outer side of the inner cylindrical body And a sphere that contacts the inner wall of the cylinder.

  And this invention can also be the structure which distributes the said spherical body in multiple numbers in these outer cylinders or inner cylinders.

  In addition, the present invention may be configured such that the sphere is adsorbed and supported by a magnetic body provided on the outer cylinder or the inner cylinder.

  Furthermore, the present invention is configured to adsorb the spheres to the magnetic body provided in the outer cylinder body or the inner cylinder body, and attach the outer cylinder body to the holding portion formed in the outer cylinder body or the inner cylinder body. A configuration in which the hollow portion or the inner cylindrical body is held so as to protrude is also possible.

  Furthermore, the present invention is such that the sphere is fitted into a partial spherical recess formed on the hollow side of the outer cylinder or the outer periphery of the inner cylinder, and is attached to the outer periphery of the inner cylinder or the inner wall of the outer cylinder. A configuration of abutting is also possible.

  Moreover, in the present invention, the sphere is formed so as to face the first curved stepped portion formed on the hollow portion side of the outer cylindrical body and the first curved stepped portion on the outer peripheral side of the inner cylindrical body at a slight interval. A configuration that fits between the second curved stepped portions is also possible.

  And as for the above-mentioned drive source, the present invention is a drive magnet arranged on the hollow part side of these outer cylinders or the outer peripheral side of the inner cylinder, and on the outer periphery side of these inner cylinders or the hollow part side of the outer cylinder. You may form with the linear motor which has the coil which arrange | positions and produces the stress of an axial direction between the drive magnets by switching of a drive current.

  In such an advancing / retracting drive device according to the present invention, the inner cylinder is inserted into the hollow portion of the outer cylinder with a slight interval, and one of the outer cylinder and the inner cylinder is connected to the other by the drive source. The spheres are relatively moved forward and backward so that the spheres rotatably supported on the inner wall side of the outer cylindrical body or the outer peripheral side of the inner cylindrical body are brought into contact with the outer periphery of the inner cylindrical body or the inner wall of the outer cylindrical body. Therefore, the inner cylinder or the outer cylinder can move forward and backward with a small load with respect to the other, and it is easy to reduce the capacity, cost and size of the power battery.

  In the configuration in which a plurality of the spheres are dispersedly arranged in the outer cylinder or the inner cylinder, the inner cylinder can be stably supported.

  Moreover, in the structure which adsorb | sucks and supports the said spherical body to the magnetic body provided in those outer cylinder bodies or an inner cylinder body, the spherical body is easy to be hold | maintained and the handling of the spherical body at the time of an assembly is easy.

  Further, in the configuration in which the sphere is arranged in a holding portion provided on the outer cylinder or the inner cylinder and is protruded by being attracted to the magnetic body, the sphere is more easily held and the sphere is handled at the time of assembly. It is even easier.

  Furthermore, in the configuration in which the spheres are fitted into the partial spherical concave portions formed on the hollow part side of the outer cylinders or the outer peripheral side of the inner cylinders, and contact the outer periphery of the inner cylinders or the inner wall of the outer cylinders. It is possible to hold the sphere without using a magnet or the like, and it is difficult to increase the number of parts.

  In addition, a magnet or the like may be fitted between the first curved stepped portion formed on the hollow portion side of the outer cylindrical body and the second curved stepped portion formed facing the outer peripheral side of the inner cylindrical body. Without using the sphere, it is more reliable to hold the sphere and it is difficult to increase the number of parts.

  And as said drive source, a drive magnet is arrange | positioned in the hollow part side of these outer cylinders, or the outer peripheral side of an inner cylinder, and it has a coil in the outer peripheral side of these inner cylinders, or the hollow part side of an outer cylinder. If the linear motor is configured, the configuration can be simplified and miniaturized.

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

  FIG. 1 and FIG. 2 are a transverse sectional view (cross section taken along line I-I in FIG. 2) and a longitudinal sectional view showing an embodiment of the forward / backward drive device according to the present invention.

  1 and 2, the inner cylinder 15 is formed in a cylindrical shape from a non-magnetic synthetic resin, for example, polycarbonate, and a lens 17 (not shown other than FIG. 2) as a movable part is formed in the hollow portion 15a. It is fixed so as to close the hollow portion 15a.

  The inner cylinder 15 has three through-holes 19 penetrating inside and outside at the same angle of, for example, 120 ° on the same circumference.

  Chip-like drive magnets 21 are press-fitted into these through holes 19 so as to slightly protrude from the outer periphery of the inner cylinder 15 (see FIG. 3). A yoke 23 made of a steel plate is fitted into and in contact with the hollow portion 15a side).

  The drive magnet 21 is a conventionally known magnet that is magnetized so that N poles and S poles are arranged in the axial direction of the inner cylinder 15 in a state of being disposed in the inner cylinder 15.

  The outer cylinder 25 is formed into a thin shape with a thickness slightly longer than the axial length of the inner cylinder 15 from a non-magnetic synthetic resin, for example, polycarbonate, and the outer shape is a square shape.

  The outer cylinder 25 has three identical and arcuate guide pieces 27 arranged in an annular shape dispersed at an equal angle of 120 ° when viewed from the center of the hollow portion 25a. A part of the outer cylinder 25 is formed in a state of being integrally provided upright from the outer cylinder 25 on one end face side (right end in FIG. 2) of the cylinder 25.

  An inner wall of the hollow portion 25a of the outer cylinder 25 is formed by three guide pieces 27 arranged in an annular shape, and a slit 29 is formed between adjacent guide pieces 27.

  As shown in FIGS. 1, 4, and 5, the outer cylindrical body 25 is inserted into the outer periphery of the guide piece 27 arranged in an annular shape with a concave cross section that opens to the other end face side (left side end in FIG. 2). The groove 31 is formed in a ring shape, and in the region overlapping the slit 29 between the adjacent guide pieces 27, a concave storage portion 33 is formed on the other end surface side (left end in FIG. 2) like the insertion groove 31. Each is formed to open.

  Accordingly, the slits 29 and the storage portions 33 are also distributed and arranged at the same position at an equal angle of 120 °.

  A holding hole 35 is formed in the middle of each guide piece 27 of the outer cylinder 25 at a position at an equal angle of 120 ° when viewed from the center of the hollow portion 25a, and the holding hole 35 is also formed in the outer cylinder 25 itself. A through hole 37 that communicates with the outer circumference is formed to communicate with the outer periphery.

  Returning to FIG. 1, a circuit board 39 is inserted into the insertion groove 31 of the outer cylinder 25.

  As shown in FIG. 6A, the circuit board 39 is a conventionally known long and slender sheet-like flexible circuit board, and a coil 41 formed by winding a conducting wire in a rectangular frame shape is soldered and connected at equal intervals on one side thereof. A through hole 43 formed between the coils 41 and at a predetermined distance from the coil 41 is formed in the same straight line as the coils 41, and the drive current of the coils 41 is switched and energized. It is.

  Reference numeral 45 in FIG. 6A denotes a Hall element that detects the magnetic pole position of the drive magnet 21 of the inner cylinder 15.

  As shown in FIG. 6B, a rectangular board yoke 47 made of a steel plate and slightly larger than the planar shape of the coil 41 is fixed to the circuit board 39 so as to overlap the coil 41. Has been.

  The circuit board 39 is inserted into the insertion groove 31 so that the coil 41 and the yoke 47 are fitted into the slit 29 and the storage portion 33 of the outer cylindrical body 25, and the insertion hole 43 is aligned with the holding hole 35 and the through hole 37. It is being fixed to the inner wall of the insertion groove 31 of the outer cylinder 25 by suitable means, such as an agent.

  The circuit board 39 is led out to the outside through a groove 49 provided in the outer cylinder 25 as shown by a broken line in FIG.

  The inner cylinder 15 described above is inserted into the hollow portion 25a of the outer cylinder 25 so that the drive magnet 21 faces the coil 41 and the yoke 47 with a slight gap.

  As shown in FIGS. 1 and 2, the sphere 51 made of a hard material such as a ball bearing sphere is smoothly inserted into the through-hole 37 from the outer periphery of the outer cylinder 25, and the through-hole 37 is also similarly used. In contact with the chip-like magnet 53 press-fitted into the magnet 53 and attracted to the magnet 53, the hollow portion 25a is in contact with the outer periphery of the inner cylindrical body 15 while being held in the holding hole 33 in a loosely inserted state.

  In the forward / backward drive device having such a configuration, as shown in FIG. 7, by changing the direction and intensity of the drive current flowing in the coil 41 on the circuit board 39 based on the magnetic pole detection signal from the Hall element 45. When, for example, an N pole is generated on the end face of the coil 41, a stress is generated in the drive magnet 21 magnetized on the N pole and the S pole in the axial direction so that the N pole side overlaps the center of the end face of the coil 41.

  Therefore, the inner cylinder 15 to which the drive magnet 21 is fixed changes in the axial direction T as shown by a broken line with respect to the outer cylinder 25 (not shown in FIG. 7). For example, if the figure is shown in FIG. (The reverse direction to FIG. 7).

  That is, a linear motor is constituted by the drive magnet 21 arranged on the inner cylinder 15 side, the circuit board 39 arranged on the outer cylinder 25 side, the coil 41, the hall element 45, and the like. The cylinder 15 functions as a rotor, and the outer cylinder 25 side on which the circuit board 39 with the coil 41 and the hall element 39 is disposed functions as a stator.

  Moreover, the inner cylinder 15 disposed at a slight interval from the outer cylinder 25 is supported by the sphere 51 in a point contact state with the outer cylinder 25, and the sphere 51 is easily rotated. Therefore, when the inner cylinder 15 changes with respect to the outer cylinder 25, the inner cylinder 15 changes with a very small force.

  In such an advancing / retracting drive device of the present invention, the three drive magnets 21 are arranged at equal angles in the through hole 19 provided in the inner cylinder 15 so as to protrude to the outer periphery, and the hollow portion 25a of the outer cylinder 25 is provided. On the side, three arc-shaped guide pieces 27 are formed, and slits 29 are formed between the adjacent guide pieces 27. The guide pieces 27 are provided with holding holes 35 and are inserted into the insertion grooves 31 on the outer periphery of the guide pieces 27. Is formed in the outer cylindrical body 25 in the region overlapping the slit 29, while the circuit board 39 is formed with insertion holes 43 at a predetermined interval, and the coil 41 is provided on one side, A yoke 47 is arranged on the opposite surface, and the circuit board 39 is inserted into the insertion groove so that the coil 41 and the yoke 47 are inserted into the slit 29 and the storage portion 33 of the outer cylinder 25 and the insertion hole 43 is aligned with the holding hole 35. Insert into 31 The spherical body 51 and the magnet 53 are inserted from the through hole 37 formed in the outer cylindrical body 25, and the spherical body 51 adsorbed by the magnet 53 is inserted into the holding hole 33 with respect to the inner cylindrical body 15 inserted into the hollow portion 25 a of the outer cylindrical body 25. While being held, it was configured to abut on the outer periphery of the inner cylinder 15 in a point contact state.

  Therefore, the inner cylinder 15 arranged at a slight interval from the outer cylinder 25 is pivotally supported by the outer cylinder 25 in a point contact state with the sphere 51 with respect to the outer cylinder 25, and the sphere 51 is rotatable. Therefore, the inner cylinder 15 can be shifted with respect to the outer cylinder 25 with an extremely small force.

  Therefore, since the load for moving the inner cylinder 15 is small and the drive current flowing through the coil 41 may be small, the drive power, particularly the power supply capacity of the power supply battery can be reduced, and power saving can be dealt with. According to the inventor's experiment, the power consumption can be reduced to ½ to ¼ in substantially the same configuration.

  Further, it is possible to reduce the number of turns of the coil 41, and it is not necessary to increase the magnetizing strength of the magnet 25, so that cost reduction and size reduction are easy.

  Furthermore, since the spheres 51 are distributed and arranged at an equal angle of 120 ° in the circumferential direction of the outer cylinder 25 and the inner cylinder 15, the inner cylinder 15 is coaxially arranged in the outer cylinder 25 and the characteristics are also improved. Stable and highly accurate.

  Note that the spherical body 51 does not necessarily have to be arranged at an equal angle of 120 ° in the circumferential direction of the outer cylindrical body 25 and the inner cylindrical body 15, but there is an advantage that it is difficult to be eccentric when arranged at an equal angle.

  Further, since the magnetic sphere 51 is attracted to the magnet 53, the sphere 51 is stably held, and handling of the sphere during assembly is easy.

  Furthermore, since the sphere 51 is held in the holding hole 35 as the holding portion of the guide piece 27 with a little play, the sphere 51 is held more stably, and handling of the sphere at the time of assembly is further simplified.

  In the configuration described above, the inner cylinder 15 is supported by the three spheres 51 in a point contact state with respect to the outer cylinder 25, but is fixed to the three drive magnets 21 and the outer cylinder 25. Since the attracting force acts in a face-to-face state between the three yokes 47, the outer cylinder 25 is stably held coaxially.

  However, as shown in FIG. 8, a plurality of spheres 51 may be arranged in the axial direction of the inner cylinder 15 and the outer cylinder 25.

  Furthermore, as shown in FIG. 9, a plurality of spheres 51 can be arranged between the coils 41 in the circumferential direction of the inner cylinder 15 and the outer cylinder 25.

  In the configuration shown in FIG. 9, some of the spheres 51 are indicated by broken lines, and some of the holding holes 35 and the through holes 37 are not shown.

  In such a configuration, a plurality of holding holes 35 and through holes 37 are provided in the outer cylinder 25 and the circuit board 39, but the inner cylinder 15 can be supported more stably with respect to the outer cylinder 25. It becomes.

  Further, in the present invention, a holding structure of the sphere 51 as shown in FIGS. 11A and 11B is possible.

  That is, FIG. 11A shows a configuration in which a partially spherical concave portion 55 is formed on the hollow portion 25a side of the guide piece 27 of the outer cylindrical body 25, and the spherical body 51 is fitted into this to contact the outer periphery of the inner cylindrical body 15. Even if it is not attracted to the magnet 53, the sphere 51 can be held between the outer cylinder 25 and the inner cylinder 15, and parts such as the magnet 53 are not increased.

  11B shows that the first curved stepped portion 57 is formed on the outer peripheral side of the inner cylinder 15 by forming a partially spherical first curved stepped portion 57 on the hollow portion 25a side of the guide piece 27 of the outer cylindrical body 25. The second curved stepped portion 59 having the same partial spherical shape facing the surface 57 with a slight gap is formed, and the sphere 51 is suitable between the first curved stepped portion 57 and the second curved stepped portion 59. The structure which clamps in the state which applied the preload is shown.

  Even in this configuration, the sphere 51 can be held more stably between the outer cylinder 25 and the inner cylinder 15 without using the magnet 53.

  By the way, in the advancing / retracting drive device of the present invention described above, the inner cylinder body 15 side is described as a rotor and the outer cylinder body 25 side is described as a stator. However, the present invention is not limited to this, and the drive magnet 21 is an outer cylinder body. The circuit board 39 and the coil 41 are arranged on the inner cylinder 15 side on the inner wall side of the hollow portion 25a of the 25, and either one of the configurations such as a configuration in which the inner cylinder 15 side is a stator and the outer cylinder 25 side is a rotor is relatively Can be changed.

  Further, if one or more spheres 51 are used, the object of the present invention can be achieved, and the configuration is not limited to the configuration in which the outer cylinder 25 is attracted or held, but can be implemented in the configuration in which the inner cylinder 15 is attracted or held. The magnet 53 is not essential.

  In the configuration in which the sphere 51 is held on the inner cylinder 15 side, a holding portion or a magnet 53 corresponding to the holding hole 35 described above may be disposed on the inner cylinder 15 side and held in a state of being held or attracted.

  Furthermore, the inner cylinder 15 and the outer cylinder 25 described above are not limited to a cylindrical shape, and can be implemented by various polyhedral cylinders. The guide piece 27 described above is not essential, and the guide piece 27 is simply omitted. It is possible to carry out by forming a circuit board and a holding hole in an outer cylinder having a hollow portion, and the outer cylinder 25 is also in a cup shape with one end face side (the right end in FIGS. 2 and 8) closed. Also good.

  Further, in the above-described advance / retreat drive device of the present invention, the linear motor configuration is used as a drive source for shifting the inner cylinder 15 with respect to the outer cylinder 25. The actuator can be implemented by an actuator such as a stepping motor or an ultrasonic motor, and if a gear is combined, a rotary motor can be used as a drive source in addition to a linear drive motor.

  However. Use of the above-described linear motor configuration is preferable because the configuration is simple and the size can be easily reduced.

  The advance / retreat drive device of the present invention is not limited to a mobile phone and a small optical device, and can be mounted on various devices that move a moving part other than an optical system such as a robot.

It is a cross-sectional view (cross section between II in FIG. 2) which shows the embodiment of the forward / backward drive device according to the present invention. It is a longitudinal cross-sectional view of the forward / backward drive device according to the present invention. It is a perspective view of the inner cylinder shown in FIG. It is a perspective view of the outer cylinder shown in FIG. It is a rear view of the outer cylinder shown in FIG. It is a perspective view of the circuit board shown in FIG. It is a figure explaining operation | movement of the advancing / retreating drive apparatus of this invention. It is a longitudinal cross-sectional view which shows other embodiment of the advancing / retreating drive apparatus of this invention. It is a cross-sectional view showing still another embodiment of the forward / backward drive device of the present invention. It is principal part sectional drawing which shows other embodiment regarding the holding | maintenance structure of the spherical body which concerns on the advancing / retreating drive apparatus of this invention. It is a longitudinal cross-sectional view of the conventional forward / backward drive device.

Explanation of symbols

1,17 Lens (movable parts)
3 Hollow shaft 5, 53 Magnet 7 Case 9, 11 Sliding body 13, 27 Coil 15 Inner cylinder 15a, 25a Hollow part 19, 37 Through hole 21 Drive magnet 23, 47 Yoke 25 Outer cylinder 27 Guide piece 29 Slit 31 Insertion Groove 33 Storage part 35 Holding hole (holding part)
39 Circuit board 41 Coil 43 Insertion hole 45 Hall element 49 Groove 51 Sphere 55 Partial spherical recess 57 First curved surface step 59 Second curved surface step

Claims (7)

An outer cylinder,
An inner cylinder inserted into the hollow part of the outer cylinder with a slight gap;
A drive source that moves one of the outer cylinder and the inner cylinder relative to the other in the axial direction of the hollow portion; and
A sphere that is rotatably supported on the inner wall side of the outer cylindrical body or the outer peripheral side of the inner cylindrical body and that contacts the outer periphery of the inner cylindrical body or the inner wall of the outer cylindrical body;
An advancing / retracting drive device comprising: The forward / backward drive device according to claim 1, wherein a plurality of the spherical bodies are dispersedly arranged on the outer cylinder body or the inner cylinder body. The forward / backward drive device according to claim 1 or 2, wherein the spherical body is adsorbed and supported by a magnetic body provided in the outer cylinder body or the inner cylinder body. The spherical body is adsorbed by a magnetic body provided in the outer cylindrical body or the inner cylindrical body, and a hollow portion of the outer cylindrical body or the inner cylindrical body is attached to a holding portion formed in the outer cylindrical body or the inner cylindrical body. The forward / backward drive device according to claim 3, wherein the forward / backward drive device is held so as to protrude from the outer periphery of the cylindrical body. The spherical body is fitted into a partially spherical recess formed on the hollow portion side of the outer cylindrical body or the outer peripheral side of the inner cylindrical body, and is in contact with the outer periphery of the inner cylindrical body or the inner wall of the outer cylindrical body. The forward / backward drive device according to claim 1 or 2. The sphere has a first curved step formed on the hollow side of the outer cylinder and a second curved step formed on the outer peripheral side of the inner cylinder with a small distance from the first curved step. The forward / backward drive device according to claim 1 or 2, wherein the forward / backward drive device is fitted between curved step portions.
Advance and retreat drive device. The drive source includes a drive magnet disposed on the hollow portion side of the outer cylinder body or the outer periphery side of the inner cylinder body, and a drive current disposed on the outer periphery side of the inner cylinder body or the hollow portion side of the outer cylinder body. The forward / backward drive device according to any one of claims 1 to 6, which is a linear motor having a coil that generates a stress in the axial direction between the drive magnet and the drive magnet.

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