JP5117785B2 - Structure of rotor built-in motor - Google Patents

Description

  The present invention relates to the structure of a motor, and more particularly to the structure of a motor with a built-in rotor.

  As is well known, the motor is widely applied to the focus adjustment structure of a digital camera. In order to reduce the volume of the camera, a camera motor installed in a lens barrel has been proposed. The motor includes a hollow cylindrical stator and a hollow cylindrical rotor installed in the stator. The lens set is accommodated in the rotor. On the contact surface with the rotor connected to the lens set, a thread portion for engagement is formed.

  When the motor is energized and the rotor is rotated, the lens set moves along the optical axis direction via the screw portion, so that the focus of the camera can be adjusted. However, since the contact surface between the screw portion of the lens set and the screw portion of the rotor leaks to the outside, dust from the outside falls on the contact surface. In addition, dust on the contact surface may enter the inside of the motor or an image sensor and affect the photograph.

  In view of the above problems, an object of the present invention is to provide a structure of a rotor built-in motor having a dustproof function.

A lens set and a motor that drives the lens set to expand and contract, and the motor and the lens set are each formed with a screw portion, and the lens set is formed by the action of the screw portion to be screwed together. in the structure of the rotor built motor driving so as to move the structure of the rotor internal motor further comprises a cover provided on the lens assembly, aperture is provided in the center of the cover, the lens assembly is an upper and a screw includes a lower part provided with a section, said motor when driven to stretch moves the lens module of the upper from the opening of the cover, conceal the screw portion of the bottom of the lens assembly in the interior of the cover.

A lens base, a stator provided in the lens base, a rotor provided in the stator, and a lens set provided in the rotor, each of the rotor and the lens set including a lens set In the structure of a rotor built-in motor provided with a screw part that drives to move the rotor, the structure of the rotor built-in motor further includes a cover for fixing the stator and the rotor to a lens base, and the lens set includes an upper part and a lower part . The upper outer wall is provided with a plurality of recessed basins formed at equal angles, and the center of the cover is provided with an opening substantially the same as the outer diameter of the upper part. extends the periphery in the radial direction, the trough plurality of guide portions formed to correspond is provided with the lens assembly of the threaded portion on the lower Vignetting, by the action of the rotor and the guide portion, even by stretching moves linearly to an upper portion of said lens assembly, lower portion of the lens assembly is hidden in a space formed by the lens base and the cover.

  Compared to the prior art, in the structure of the motor with a built-in rotor, since the cover is provided on the lens set, the screw portion of the lens set can be hidden inside the cover. Therefore, it is possible to prevent dust from the outside from entering the inside of the motor or falling to the image sensor mounted inside the motor, maintaining the cleanliness of the image sensor and improving the quality of the formed image. it can.

  Hereinafter, the configuration of an embodiment according to the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1, 2 and 3, the motor of the present invention having a rotor includes a lens base 10 (shown in FIG. 2), and a motor 30 provided in the lens base 10 (shown in FIG. 3). And a lens set 50 driven by the motor 30 and a cover 70 provided on the lens set 50.

  The lens base 10 includes an upper frame base 12 and a lower frame base 14 that engages with the upper frame base 12. A space for accommodating the motor 30 and the lens set 50 is defined between the upper frame base 12 and the lower frame base 14.

  The structures of the upper frame base 12 and the lower frame base 14 are substantially the same. The upper frame base 12 includes a hollow cylindrical side wall 121 and a notch 126 formed at one end of the side wall 121. The lower frame base 14 also includes a hollow cylindrical side wall 141 and a notch 146 formed at one end of the side wall 141. When the upper frame base 12 and the lower frame base 14 are assembled so that the notches 126 and 146 face each other, a hole 18 is formed between the notch 126 and the notch 146 (shown in FIG. 2). Electricity is supplied only to the motor 30 through the hole 18. In order to connect the upper frame base 12 and the lower frame base 14, it is convenient to provide engaging portions (not shown) on the upper frame base 12 and the lower frame base 14.

  The motor 30 is a stepping motor installed inside a space defined in the lens base 10. The motor 30 includes a stator 32 and a rotor 34 that is rotatably accommodated in the stator 32.

  The stator 32 is a cylindrical body. The stator 32 includes a stator coil base 321 and a coil 322 wound around the stator coil base 321 along the rotation axis direction. The coil 322 is electrically connected to an external power source. The coil base 321 is an annular body in which a columnar space for accommodating the rotor 34 is defined. A plurality of pole pieces 323 are provided on the inner peripheral surface of the coil base 321. A plurality of protrusions 324 projecting toward the upper frame base 12 are provided at the upper end of the coil base 321. The protrusions 324 are provided at equal intervals along the circumferential direction of the columnar space. An annular convex edge 326 extending toward the lower frame base 14 and coaxial with the columnar space is formed on the inner edge at the lower end of the coil base 321.

  The outer diameter of the stator 32 and the inner diameter of the lens base 10 are substantially the same. Since the outer peripheral surface of the stator 32 is pressed against the inner wall surface of the lens base 10, the stator 32 is fixed inside the lens base 10. Power is supplied to the coil 323 through the hole 18.

  The rotor 34 is accommodated in a columnar space formed in the stator 32. The rotor 34 includes a cylindrical magnet 341 and a guide ring 342 installed at the top end of the magnet 341. The bottom end of the magnet 341 is disposed on the convex edge 326 of the coil base 321 of the stator 32. The guide ring 342 is a cylindrical hollow body having an annular engagement portion 343 formed at the bottom end. The inner diameter of the engaging portion 343 and the inner diameter of the guide ring 342 are the same. The engaging portion 343 is engaged in the magnet 341 so that the guide ring 342 is fixed inside the magnet 341. An inner screw portion 344 for moving the lens base 50 is provided on the inner wall of the guide ring 342.

The lens set 50 is installed in the rotor 34. The lens set 50 includes a cylindrical columnar upper portion 51 and a cylindrical columnar lower portion 54. The outer wall of the lower portion 54 is provided with an outer screw portion 544 that is screwed with the inner screw portion 344 of the guide ring 342. The outer diameter of the upper part 51 is smaller than the outer diameter of the lower part 54, and a plurality of concave tubs 541 are provided on the outer wall of the upper part 51 so as to be spaced apart from each other.

The annular cover 70 covers the upper end of the lens set 50. An opening 71 is provided in the middle of the cover 70. The outer diameter of the cover 70 and the outer diameter of the lens base 10 are substantially the same. The diameter of the opening 71 is smaller than the outer diameter of the lower portion 54 of the lens set 50 and slightly larger than the outer diameter of the upper portion 51. The cover 70 is provided with a plurality of narrow grooves 724 formed at equal intervals along the circumference. The plurality of narrow grooves 724 are respectively engaged with the protrusions 324 of the coil base 321, and the cover 70 can be prevented from moving and being removed. A plurality of guide portions 741 extending in the radial direction and formed so as to correspond to the concave tank 541 of the lens set 50 are provided on the inner edge of the cover 70. The guide portion 741 is engaged with a concave tank 541 provided on the outer wall of the upper portion 51 of the lens set 50 to control the rotation of the lens set 50 along the circumferential direction. In addition, the lens set 50 can be prevented from moving and shaking.

When assembling a motor including a rotor, the lens set 50 is first mounted in the rotor 34. Then, the external thread portion 544 provided on the external wall of the lower portion 54 of the lens assembly 50 is screwed with the internal thread portion 344 provided on the internal wall of the guide ring 342 of the rotor 34. Next, the rotor 34 is accommodated in a columnar space formed in the stator 32. Then, the bottom end of the magnet 341 of the rotor 34 is mounted on the convex edge 326 of the coil base 321 of the stator 32, and the stator 32 is in a space defined by the lower frame base 12 and the upper frame base 14. Is housed in. Next, the lens set 50 is covered with the cover 70 so that the narrow groove 724 of the cover 70 is engaged with the protrusion 324 of the coil base 321. Then, the guide part 741 at the inner edge of the cover 70 is engaged with the concave tank 541 on the outer wall of the upper part 51 of the lens set 50.

In the motor having the rotor shown in FIG. 4, when a power source is electrically connected to the coil 322 of the stator 32, the rotor 34 moves the rotation center axis of the motor by the magnetic field action between the coil 322 and the magnet 341 of the rotor 34. Rotate to center. The rotational movement of the rotor 34 is converted into the linear movement of the lens set 50 by the action of the screw part between the rotor 34 and the lens set 50 and the action of the guide part 741 of the cover 70. That is, the upper portion 51 of the lens set 50 can be expanded and contracted in and out of the cover 70, and the focus can be automatically adjusted.

As described above, since the guide portion 741 is provided on the inner wall of the cover 70, the lens set 50 rotates together with the rotor 34 to guide the lens set 50 to move along a straight line. . Further, since the inner diameter of the cover 70 is smaller than the outer diameter of the lower portion 54 of the lens set 50, the outer threaded portion 544 of the outer wall of the lower portion 54 can be hidden in the lens base 10. If the minimum distance from the center of the inner edge of the cover 70 to the guide portion 741 is smaller than the radius of the lower portion 54 of the lens set 50, the outer screw portion 544 of the lens set 50 and the inner screw portion 344 of the rotor 34. Can be hidden inside the cover 70. Accordingly, it is possible to prevent external dust from entering the inside of the motor from the contact surface or falling to an image sensor (not shown) mounted inside the motor. That is, it is possible to maintain the cleanliness of the image sensor and improve the quality of the formed image.

It is a three-dimensional exploded view of the best embodiment of the structure of the rotor built-in motor of the present invention. FIG. 2 is a three-dimensional assembly diagram of the structure of the motor shown in FIG. 1. It is sectional drawing of the structure of the motor shown in FIG. FIG. 3 is a view showing a work state of the motor structure shown in FIG.

10 Lens Hose 12 Upper Frame Base 14 Lower Frame Base 18 Hole 30 Motor 32 Stator 34 Rotor 50 Lens Set 51 Upper 54 Lower 70 Cover 71 Opening 121 Side Wall 126 Notch 141 Side Wall 146 Notch 321 Coil Base 322 Coil 323 Pole Piece 324 Protrusion 326 Convex edge 341 Magnet 342 Guide ring 343 Engagement part 344 Inner thread part 541 Recessed tank 544 Outer thread part 724 Narrow groove 741 Guide part

Claims (7)

A lens set and a motor that drives the lens set to expand and contract,
In the structure of a motor with a built-in rotor that is driven to move the lens set by the action of the screw part that is screwed into the motor and the lens set, respectively.
The structure of the rotor built-in motor further includes a cover provided on the lens set;
An opening is provided in the center of the cover;
The lens set includes an upper part and a lower part provided with an external thread part at an upper end part ,
The motor includes a stator, a rotor housed in the stator, a cylindrical magnet, and a guide ring that is installed at the top end of the magnet and is provided with an inner screw portion that is screwed with the outer screw portion. Including
An annular engagement portion formed at the bottom end of the guide ring is fixed inside the magnet,
The outer diameter of the outer screw portion in the lower portion of the lens set is smaller than the outer diameter of a portion other than the outer screw portion in the lower portion,
A structure of a motor with a built-in rotor, wherein when the motor is driven to expand and contract the upper part of the lens set from the opening of the cover, the screw part at the lower part of the lens set is hidden inside the cover. The structure of the motor with a built-in rotor according to claim 1, wherein an outer diameter of an upper portion of the lens set is smaller than an outer diameter of a lower portion of the lens set. The outer wall at the top of the lens set is provided with a plurality of concave tubs formed at equal intervals,
3. The rotor built-in motor according to claim 1, wherein a plurality of guide portions extending in a radial direction at the inner edge of the cover and corresponding to the concave tub are provided. 4. Construction. The upper end of the front Symbol stator, a plurality of protrusions protruding to the side of the cover is provided,
The structure of a motor with a built-in rotor according to claim 1, wherein the cover is provided with a plurality of narrow grooves engaging with the protrusions. An annular convex edge extending inward is formed on the inner edge of the lower end of the stator ,
Structure of Rotor internal motor according to claim 4, wherein the pre-Symbol rotor is mounted on the projecting edge. The structure of the motor with a built-in rotor further includes a lens base that houses the motor and a lens set;
The cover is provided on the lens base;
2. The structure of a motor with a built-in rotor according to claim 1, wherein the outer diameter of the cover and the outer diameter of the lens base are substantially the same. The structure of a motor with a built-in rotor according to claim 6 , wherein a hole for supplying power is provided in a side wall of the lens base.

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