JP2008135129A - Chucking device and its manufacturing method, brushless motor incorporating this chucking device, and disk drive incorporating this brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chucking device and its manufacturing method making no chucking errors even if the metal die wears forming burrs, and also to provide a brushless motor incorporating this chucking device. <P>SOLUTION: Curves 31c11, 31c21 are formed around the centering pieces 31c of the chucking device 30, and chamfers 31a1, 31b1 are also formed at the ends of openings 31d holding those centering pieces 31c. Those curves 31c11, 31c21 and chamfers 31a1, 31b1 are made large enough so that the upper sections of the burrs 35, 36 do not stick out from the disk contact surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a chucking device that allows a disk-shaped disk such as an optical disk to be detachable, and a brushless motor equipped with the chucking device.

Conventionally, a chucking device that allows a disk-shaped optical disk to be detachable is formed by molding a resin material with a mold. 16 and 17 show a conventional chucking device. 16 shows a top view of the chucking device, and FIG. 17 shows a schematic cross-sectional view of the chucking device cut in the axial direction.

Referring to FIG. 16, a chucking device 1 includes a substantially cylindrical centering case 2 centered on a predetermined center axis J1 through which an optical disk (not shown) is inserted, a radial center of the optical disk, and a centering case. 2 is provided with a centering claw 3 that acts so as to coincide with the center in the radial direction of 2 and a placement portion 4 on which an optical disk is placed. The alignment claw 3 is accommodated in an accommodation opening 2 a formed in the centering case 2.

Next, referring to FIG. 17, a guide portion 2 b that guides the optical disk to the alignment claw 3 and is inclined radially outward and downward in the axial direction is formed on the upper portion of the centering case 2. The accommodation opening 2a in the centering case 2 is formed from the cylindrical portion 2c of the centering case 2 to the guide portion 2b. An inner wall 2d extending along the axial direction is formed at the upper edge of the accommodation opening 2a. And the alignment nail | claw 3 has a gap | interval in radial direction with respect to the inner wall part 2d, and is arrange | positioned radially outside (refer the patent document 1 for an example of such a chucking apparatus).

JP 2000-113544 A

However, when the chucking device 1 is manufactured in a large amount (for example, hundreds of thousands to millions) using a mold, the mold is worn. Next, molding of the chucking device when the mold is worn will be described with reference to FIGS. FIG. 18 is a schematic cross-sectional view taken along the axial direction showing a part of the worn mold 5 of the chucking device 1. FIG. 19 is a schematic cross-sectional view cut in the axial direction showing the time when the upper mold 5a is released (a state where the upper mold 5a is pulled out).

Referring to FIG. 18, a mold 5 for molding the chucking device 1 includes an upper mold 5 a that is a movable side and a lower mold (not shown) that is a fixed side. The upper mold 5a forms the upper surface of the alignment claw 3 and the upper part of the outer surface of the inner wall 2d. The lower mold forms the lower surface of the centering case 2. Further, the upper mold 5a has a gap insertion part 5a1 that is inserted into the accommodation opening 2a in order to form the alignment claw 3. Further, every time the chucking device 1 is molded, the vicinity of the gap insertion portion 5a1 of the upper mold 5a comes into contact with the lid surface of the inner wall portion 2d. Therefore, a recessed portion 5a2 due to wear is formed in the vicinity of the gap insertion portion 5a1 in contact with the inner wall portion 2d of the upper mold 5. And this recessed part 5a2 will be filled with the resin material.

Referring to FIG. 19, when the upper mold 5a is released upward in the axial direction, the resin material filled in the recess 5a2 is pulled as it is in the upper axial direction. Then, the burr 2a1 is formed at the periphery of the accommodation opening 2a. The burr portion 2a1 protrudes outward from the guide portion 2b, thereby coming into contact with the inner peripheral surface of the optical disk. And there is a possibility that the optical disk does not slide smoothly on the guide part 2b by the burr part 2a1. As a result, the burr 2a1 obstructs the mounting of the optical disk, and an optical disk mounting error occurs.

Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to provide a chucking device that does not cause an optical disc mounting error even when a burr portion generated by wear of a mold is formed. The manufacturing method is to provide a brushless motor equipped with this chucking device.

According to the first aspect of the present invention, in the chucking device in which the disc-shaped disc having the central opening is detachable from the one side with respect to the central axis of the rotary mounting portion, the central opening of the disc-shaped disc is provided. A substantially cylindrical centering case that is inserted into contact with at least the inner peripheral edge of the center opening, and the center of the disk-shaped disk is adjusted so as to coincide with the center of the centering case in the radial direction. A centering claw having a centering function, wherein the centering case and the centering claw are integrally formed of a resin material using a mold, and the centering case accommodates the centering claw A contact avoiding portion that has an opening and avoids contact between a burr generated on the one side when the mold is released and an inner peripheral surface of the disk-shaped disc at the periphery of the accommodation opening. Made is characterized in that is.

According to claim 1 of the present invention, the disk-shaped disc is formed in the burr portion by forming a contact avoidance portion for preventing contact between the burr portion generated in the mold and the disc-shaped disc at the periphery of the accommodation opening. It can be satisfactorily placed on the placement portion without being caught. Therefore, a chucking error of the disk-shaped disk can be prevented.

According to a second aspect of the present invention, according to the first aspect, the contact avoiding portion is formed by making a peripheral edge of the accommodation opening portion a chamfered shape or a curved shape.

According to a third aspect of the present invention, in accordance with the first aspect, the contact avoiding portion is formed as a stepped portion having an inner side of the peripheral edge on the lower side in the axial direction on the peripheral edge of the accommodating opening. To do.

According to the second and third aspects of the present invention, the centering case can be easily formed by making the contact avoiding portion a chamfered portion, a curved surface shape, and a simple stepped shape.

According to claim 4 of the present invention, in the chucking device that allows the disk-shaped disk having the center opening to be detachably attached to the rotation mounting surface from one side with respect to the rotation center line, the disk is formed in the substantially cylindrical shape. A centering case through which the central opening of the disc-shaped disc is inserted, abuts on at least an inner peripheral edge of the central opening, and a radial center of the disc-shaped disc and a radial center of the centering case coincide with each other. A centering claw having a centering function that acts as described above, wherein the centering case and the centering claw are integrally formed of a resin material using a mold, and the centering case includes the centering claw. A holding opening for receiving the nail, and the periphery of the aligning nail is in contact with the burr portion generated on the one side when the mold is released and the inner peripheral surface of the disk-shaped disc; Avoid Wherein the contact avoidance portion is formed.

According to claim 4 of the present invention, the contact between the burr and the disc-shaped disk can be prevented by providing the contact avoiding portion on the periphery of the alignment claw. Therefore, the disk-shaped disc can be satisfactorily placed on the placement portion without being caught by the burr portion.

According to a fifth aspect of the present invention, according to the fourth aspect, the contact avoiding portion is formed by forming a peripheral edge of the alignment claw into a chamfered shape or a curved surface shape.

According to claim 5 of the present invention, the alignment claw can be easily formed by making the peripheral edge of the alignment claw into a simple chamfered shape or curved shape.

According to a sixth aspect of the present invention, according to any one of the first to fifth aspects, the alignment claw includes a connecting portion that connects the alignment portion and the centering case, and the contact avoidance is provided. The portion is formed as a contact avoidance portion by forming the connecting portion so as to be located radially inward and axially downward with respect to the outer surface of the centering case.

According to claim 6 of the present invention, the connecting portion is located radially inward and axially lower than the outer surface of the centering case, so that even if a burr portion is generated in the connecting portion, the connecting portion is connected to the disk-shaped disc. Therefore, the disk-shaped disc can be satisfactorily placed on the placement portion.

According to a seventh aspect of the present invention, according to any one of the first to fifth aspects, the centering case has an extending portion extending radially outwardly connected to the mounting portion, and the accommodating opening portion. Is formed up to the outer peripheral side of the extension portion, and the aligning claw extends radially inward from one surface on the outer peripheral side of the receiving opening, and is substantially the same as a position where it is connected to the extension portion of the centering case. In the position, it has the alignment part extended to an axial direction upper side, It is characterized by the above-mentioned.

According to claim 8 of the present invention, a shaft serving as a rotating shaft, a rotor magnet that rotates integrally with the shaft, an armature that faces the rotor magnet with a gap therebetween, and claims 1 to 7 A brushless motor comprising: a chucking device according to any one of
The chucking device is disposed coaxially with the shaft and is disposed on the upper side in the axial direction from the armature.

According to claim 8 of the present invention, it is possible to provide a brushless motor with good disc-shaped disk mounting properties.

According to the present invention, there is provided a chucking device that does not cause an optical disc mounting error even when a burr portion generated by wear of a mold is formed, a manufacturing method thereof, and a brushless motor equipped with the chucking device. Can do.

<Overall structure of brushless motor>
One embodiment of the brushless motor of the present invention is shown in FIG. FIG. 1 is a schematic cross-sectional view of a brushless motor cut in the axial direction.

Referring to FIG. 1, the brushless motor includes a rotating body 10 including a rotor magnet 11, and a stator 21 having a surface facing the rotor magnet 11 with a small gap in the radial direction, and supports the rotating body 10. It comprises a body 20 and a chucking device 30 that allows the disk to be freely attached and detached.

First, the rotating body 10 will be described.

The rotating body 10 includes a shaft 12 serving as a rotation axis J1, a rotor holder 13 that is fixed to the shaft 12 and formed into a substantially covered cylindrical shape by pressing a steel plate, and an inner peripheral surface of a cylindrical portion 13a of the rotor holder 13. An annular rotor magnet 11 is fixed, and an annular preload magnet 14 is fixed to the lower surface of the lid portion 13b of the rotor holder 13.

Next, the fixed body 20 will be described.

The fixed body 20 is fixed to a housing 22 formed into a substantially bottomed cylindrical shape by pressing a steel plate and an inner peripheral surface of a cylindrical portion 22a of the housing 22, and substantially supports the shaft 12 to be rotatable in the radial direction. A cylindrical sleeve 23, a stator 21 fixed to the outer peripheral surface of the cylindrical portion 22a of the housing 22, and a mounting plate fixed to the outer peripheral surface of the cylindrical portion 22a of the housing 22 and disposed on the lower side in the axial direction of the stator 21 24, a circuit board 25 fixed to the upper surface of the mounting plate 24,
A thin thrust plate 26 which is disposed on the upper surface of the bottom 22b of the housing 22 and supports the shaft 12 rotatably in the axial direction.

The sleeve 23 is formed of a sintered body containing oil. In addition, a stepped portion 22c having a reduced diameter is formed on the lower side in the axial direction of the cylindrical portion 22a of the housing 22. An annular plate 27 is disposed on the upper surface of the step portion 22c. The plate 27 is fixed by being sandwiched between the upper surface of the step portion 22 c and the lower surface of the sleeve 27. Further, a reduced diameter portion 12a is formed at a position facing the plate 27 of the shaft 12. The inner peripheral surface of the plate 27 is disposed close to the outer peripheral surface of the reduced diameter portion 12 a in the radial direction, and is disposed radially inward from the other outer peripheral surface of the shaft 12. As a result, the plate 27 serves as a retaining mechanism for the shaft 12.

At the upper end portion of the housing 22, a flange portion 22 d that extends outward in the radial direction is formed. The upper surface of the flange portion 22d and the lower surface of the preload magnet 14 face each other with a small gap. An axial magnetic attractive force acts between the flange 22d and the preload magnet 14 between them. Therefore, the rotation of the rotating body 10 is stabilized by the axial force generated by the preload magnet 14.

The shaft 12 protrudes axially above the rotor holder 13. A chucking device 30 that allows a disc-like disk (not shown in FIG. 1) to be detachable is fixed to the rotor holder 13 so as to be coaxial with the shaft 12 so as to be on the upper side of the rotor holder 13. The chucking device 30 includes a clamp magnet 34 that attracts a clamp member (not shown in FIG. 1) that presses the disk from the upper surface side.

<Structure of chucking device>
Next, the structure of the chucking device 30 of the present invention will be described with reference to FIGS. FIG. 2 is a plan view of the chucking device 30 viewed from the upper side in the axial direction, and FIG. 3 is a schematic cross-sectional view of the chucking device 30 cut in the axial direction.

Referring to FIG. 2, the chucking device 30 is formed with a centering case 31 inserted through the opening of a disk-shaped disc having an opening at the center, and a radially outer side of the centering case 31. And a placement unit 32 for performing the above. Further, the centering case portion 31 and the placement portion 32 in the chucking device 30 are integrally molded as a resin molded product with a mold. The resin material is, for example, polycarbonate (PC), poniphenylene sulfide (PPS), polyacetal (POM), or a composite material thereof. In particular, the resin material is desirably a material containing glass fibers. Thereby, the intensity | strength of the shape | molded chucking apparatus 30 can be improved.

The centering case 31 has a substantially cylindrical shape having a cylindrical portion 31a on the lower side in the axial direction and a conical portion 31b formed continuously with the cylindrical portion 31a and having a diameter reduced toward the upper side in the axial direction. Further, on the outer surface formed by the cylindrical portion 31a and the conical portion 31b of the centering case 31, there are integrally formed alignment claws 31c arranged at a predetermined interval in the circumferential direction (in this embodiment, five). ).

In the center of the centering case 31, a mounting hole 31e that is coaxial with the central axis J1 and penetrates along the axial direction is formed. And the attachment hole 31e is fixed to the outer peripheral surface of the cylindrical part fixed to the shaft 12 of the rotor holder 13. FIG. Here, the attachment hole 31e may be directly fixed to the outer peripheral surface of the shaft 12.

Referring to FIG. 3, the outer surface of conical portion 31 b serves as a guide surface that substantially matches the center of the opening of the disc with the center of centering case 31 and guides the disc to mounting portion 32. The alignment claw 31c does not protrude radially outward and axially upward from the outer surface of the conical portion 31b.

The alignment claw 31c includes a connecting portion 31c1 having an inclined surface substantially parallel to the outer surface of the conical portion 31b, and an alignment portion 31c2 that protrudes radially outward from the cylindrical portion 31a. The alignment portion 31c2 is an inclined surface that slightly extends along the radially outer side toward the lower side in the axial direction. The center of the opening of the disk and the center of the centering case 31 are adjusted to coincide with each other by contacting the outer surface of the alignment part 31c2 with the inner peripheral surface of the opening of the disk.

An accommodation opening 31d, which is an opening hole for accommodating the alignment claw 31c, is formed from the cylindrical portion 31a to the conical portion 31b of the centering case 31. Here, the alignment claw 31c is connected to only one side of the upper portion of the accommodation opening 31d.

Between the centering case 31 and the mounting portion 32, an annular radial extension portion 33 that connects them is formed. The accommodation opening 31 d is formed so as to cut out a part of the radially extending portion 33 on the inner peripheral side.

The mounting portion 32 has an annular shape and is integrally formed so as to be on the upper side in the axial direction from the radially extending portion 33. On the upper surface thereof, there is an annular rubber 32a formed of a member having high frictional resistance (in this embodiment, rubber) that prevents the disc from slipping in the circumferential direction.

An annular clamp magnet 34 that exerts a magnetic attractive force on a clamp member (not shown) for holding the disk from the upper side in the axial direction is disposed on the inner peripheral side of the conical portion 31b.

<Carrying part housing structure>
In the chucking device 30 of the present invention, particularly the periphery of the alignment claw 31c will be described with reference to FIGS. FIG. 4 is a perspective view showing the periphery of the alignment claw 31c. FIG. 5 shows the relationship between the chamfered portion 31 a 1 and the curved surface portion 31 c 11 and the burr portions 35 and 36. 5A is an enlarged view of a schematic cross section obtained by cutting the curved surface portion 31c11 in the circumferential direction, showing the relationship between the curved surface portion 31c11 and the burr portion 35, and b) is a chamfered portion 31a1 and a burr portion 36. It is the enlarged view of the schematic cross section which cut the chamfer 31a1 in the circumferential direction which showed this relationship.

  Referring to FIG. 4, chamfered portions 31 a 1 and 31 b 1 are formed at the edges of the cylindrical portion 31 a and the conical portion 31 b forming the accommodation opening 31 d, respectively. Further, curved surface portions 31c11 and 31c21 are formed on the periphery of the connecting portion 31c1 and the alignment portion 31c2 of the alignment claw 31c, respectively. 5A and 5B, the chamfered portions 31a1 and 31b1 and the curved surface portions 31c11 and 31c21 are burr portions that may occur when the mold 40 (see FIG. 6) is released. The upper end surfaces of 35 and 36 are set so as not to protrude from the disk contact surfaces DC1 and DC2 of the cylindrical portion 31a, the conical portion 31b, the connecting portion 31c1, and the alignment portion 31c2. That is, the chamfered portions 31a1 and 31b1 and the curved surface portions 31c11 and 31c21 serve as contact avoiding portions that avoid contact between the disk and the burr portions 35 and 36. Thereby, even if the burr portions 35 and 36 are generated in the mold 40, it is possible to prevent the upper end surfaces of the burr portions 35 and 36 and the disc from coming into contact with each other. Therefore, it is possible to provide a chucking device with good disk mounting properties. In addition, even if the mold 40 is worn and the burr portions 35 and 36 are generated, it is not a fatal problem as a product of the chucking device, so that the mold life can be extended. In particular, when the chucking device 30 is molded from a resin material containing glass fibers, the mold 40 is worn significantly. Therefore, the present invention is useful because the mold 40 can be used even when the wear of the mold 40 is increased when molding with a resin material containing glass fibers.

<Relationship between chucking device and mold>
Next, a process of forming the chucking device 30 with the mold 40 will be described with reference to FIGS. FIG. 6 is a schematic cross-sectional view showing almost the entire mold 40. FIG. 7 is an enlarged view in which a part of the second mold 43 is enlarged. FIG. 8 is an enlarged view of a schematic cross section in which the accommodation opening 31d in the mold 40 is cut in the radial direction.

  Referring to FIG. 6, a mold 40 is opposed to a movable first upper mold 41 that moves in the vertical direction in the drawing, and the first upper mold 41 in a movable direction (hereinafter referred to as an axial direction). A movable-side second upper die 43 (five in the embodiment) is inserted into the fixed-side lower die 42 and the first upper die 41, and is moved in the vertical direction to the upper surface side of each alignment claw 31c. ) And.

  The first upper mold 41 mainly forms the outer surface and the surface of the centering case 31. The lower mold 42 mainly forms the lower surface and the back surface of the centering case 31. The first upper mold 41 is formed with a gate portion 41 a that fills the space surrounded by the first upper mold 41, the second upper mold 43, and the lower mold 42 with the resin material.

  The lower mold 42 is provided with a coaxial pin 42a that is coaxial with the center of the centering case 31 and extends along the axial direction. The coaxial pin 42 a is inserted through the inner peripheral surface of the mounting hole 31 e in the centering case 31.

  The first upper mold 41 forms the upper surface of the peripheral edge of the accommodation opening 31d. And the chamfering inclined surface (not shown) is formed in the 1st metal mold | die 41 so that chamfering part 31a1 and 31b1 can be formed in the upper surface.

  Referring to FIG. 7, the second upper mold 43 is formed in the circumferential direction of the centering case 31 and the alignment claw 31 c in the housing opening 31 d and the upper surface formation portion 43 a that forms the upper surface shape of the alignment claw 31 c. Two gap insertion portions 43b that are inserted into the gap to be formed, and two side surface forming portions 43c that are formed on the inner surface of the gap insertion portion 43b and form the side shape of the alignment claw 31c.

  The upper surface forming portion 43a is provided so as to have a shape along the upper surfaces of the connecting portion 31c1 and the alignment portion 31c2 of the alignment claw 31c. In addition, a curved surface is formed at a position continuous from the upper surface forming portion 43a to the side surface forming portion 43c. Thereby, the periphery of the alignment nail | claw 31c can be made into a curved surface shape (R shape).

  Referring to FIG. 8, the gap insertion part 43b is inserted through the accommodation opening 31d. The gap insertion portion 43b is in contact with the inner peripheral surface of the peripheral edge of the accommodation opening 31d and the side surface of the centering claw 31c facing the inner peripheral surface in the circumferential direction. Therefore, when the centering case 31 is produced in large quantities, the gap insertion portions 43b are in contact with the side surfaces of the alignment claws 31c and the inner peripheral surface of the peripheral edge of the housing opening 31d by the number of production of the centering cases 31. As a result, there is a possibility that a part of each part that the gap insertion part 43b contacts is worn. The gap insertion portion 43b, which is partially worn, separates the second upper die 43 from the lower die 42 in the axial direction, so that the upper end of the side surface of the alignment claw 31c and the periphery of the accommodation opening 31d There is a possibility that burr portions 35 and 36 may be generated on the circumferential surface.

  However, a curved surface shape can be formed on the periphery of the alignment claw 31c by forming a curved surface shape between the upper surface forming portion 43a and the side surface forming portion 43b of the second upper mold 43. Therefore, the burr 35 generated by the worn second upper mold 43 can be prevented from protruding outward from the outer surface of the alignment claw 31c. Further, the chamfered inclined surface 41b is formed in the first upper mold 41 so that the upper end position of the burr portion 36 generated when the second mold 43 is released upward in the axial direction is coupled to the upper surface of the coupling portion 31c1. It can be prevented from being axially above the upper surface of the portion 31c1. As a result, the worn second upper mold 43 can be used continuously, so that the mold life can be extended.

<Other chucking devices>
Next, the structure of a chucking device 50 according to another embodiment of the present invention will be described with reference to FIGS.

  Referring to FIG. 9, a chucking device 50 is formed on a disk-shaped disc having an opening at the center, a centering case 51 inserted through the opening, and on a radially outer side of the centering case 51. And a placement unit 52 for the purpose. Further, the centering case 51 and the mounting portion 52 in the chucking device 50 are integrally molded by a mold as a resin molded product. A connecting portion 53 is formed between the centering case 51 and the placing portion 52 so as to extend radially outward from the lower side of the centering case 51 so as to connect them. This resin material is the same as the resin material of the chucking device 30.

  A mounting hole 51e that is coaxial with the central axis J1 and penetrates along the axial direction is formed at the center of the centering case 51. The mounting hole 51 e is fixed to the outer peripheral surface of the cylindrical portion that is fixed to the shaft 12 of the rotor holder 13. Here, the attachment hole 51 e may be directly fixed to the outer peripheral surface of the shaft 12.

The centering case 51 has a substantially cylindrical shape having a cylindrical portion 51a on the lower side in the axial direction and a conical portion 51b formed continuously with the cylindrical portion 51a and having a diameter reduced toward the upper side in the axial direction. An opening hole 51c is provided from a part of the upper portion of the conical portion 51b to the cylindrical portion 51a. The opening hole 51c is formed continuously outward in the radial direction up to the connecting portion 53. In the opening hole 51c, a centering claw 53a that extends integrally with the connecting portion 53 from the outer peripheral side of the connecting portion 53 is formed.

The alignment pawl 53a is formed at a first inclined surface 53a1 having an inclined surface with substantially the same angle as the conical portion 51b, and substantially in the radial direction with the cylindrical portion 51a, and radially outward toward the lower side in the axial direction. A second inclined surface 53a2 that abuts the disk by tilting and aligns the disk and the rotation shaft, and a radial extension 53a3 that is formed in the connecting portion 53 and continues to the connecting portion 53 are provided. When the disc is placed on the placement portion 52, the alignment claw 53a first guides the disc to the second inclined surface 53a2 by contacting the first inclined surface 53a1 and the disc. When the second inclined surface 53a2 and the disk come into contact with each other, the alignment claw 53a moves axially downward and radially inward to align the disk and place it on the mounting portion 52. Achieve.

<Carrying part housing structure>
In the chucking device 50 of the present invention, particularly the periphery of the alignment claw 53a will be described with reference to FIGS. FIG. 11 is a perspective view showing the periphery of the alignment claw 53a. FIG. 12 is a schematic diagram showing the relationship between the stepped portion, the curved surface portion, and the burr portion, and the peripheral edges of the alignment claw 53a and the opening hole 51c are cut in the circumferential direction. 12A is an enlarged view of a schematic cross section obtained by cutting the curved surface portion 53a11 in the circumferential direction, showing the relationship between the curved surface portion 53a11 and the burr portion 55, and b) is a stepped portion 51a1 and a burr portion 56. It is the enlarged view of the schematic cross section which cut | disconnected the level | step-difference part 51a1 in the circumferential direction which showed this relationship.

Referring to FIG. 11, at the edges of the cylindrical portion 51a and the conical portion 51b that form the opening hole 51c,
Step portions 51a1 and 51b1 are formed, respectively. Further, curved surface portions 53a11 and 53a21 are formed on the peripheral edges of the first inclined surface 53a1 and the second inclined surface 53a2 of the alignment claw 53a, respectively. Referring to a) and b) of FIG. 12, the stepped portions 51a1 and 51b1 and the curved surface portions 53a11 and 53a21 have a burr that may occur when the mold 60 (see FIG. 13) is released. The upper end surfaces of the protrusions of the portions 55 and 56 are set so as not to protrude from the disk contact surfaces DC3 and DC4 of the conical portion 51b and the alignment claw 53a. That is, the step portions 51a1 and 51b1 and the curved surface portions 53a11 and 53a21 serve as contact avoidance portions that avoid contact between the disk and the burr portions 55 and 56. Thereby, even if the burr parts 55 and 56 generate | occur | produce in the metal mold | die 60, it can prevent that the upper end surface of the burr parts 55 and 56 and a disk contact. Therefore, it is possible to provide a chucking device with good disk mounting properties. In addition, even if the mold 60 is worn and the burr portions 55 and 56 are generated, it is not a fatal problem as a product of the chucking device, so that the mold life can be extended.

<Relationship between chucking device and mold>
Next, a process of forming the chucking device 50 with the mold 60 will be described with reference to FIGS. FIG. 13 is a schematic cross-sectional view showing almost the entire mold 60. FIG. 14 is a schematic cross-sectional view in which the periphery of the alignment claw 53a in the mold 60 is enlarged.

  Referring to FIG. 13, a mold 60 is opposed to a first upper mold 61 on the movable side that moves in the vertical direction in the drawing, and a first upper mold 61 and a movable direction (hereinafter referred to as an axial direction). A fixed lower mold 62 and a second upper mold 63 inserted into the first upper mold 61 and forming the upper surface and side surfaces of the alignment claw 53a are provided.

The first upper mold 61 mainly forms the outer surface and the surface of the centering case 51. The lower mold 62 mainly forms the lower surface and the back surface of the centering case 51. The first upper mold 61 is formed with a gate portion 61 a that fills the space surrounded by the first upper mold 61, the second upper mold 63, and the lower mold 62 with the resin material.

  The lower mold 62 is provided with a coaxial pin 62a that is coaxial with the center of the centering case 51 and extends in the axial direction. The coaxial pin 62 a is inserted through the mounting hole 51 e in the centering case 51.

  Referring to FIG. 14, the second upper mold 63 is formed in the circumferential direction of the upper surface forming part 63a that forms the upper surface shape of the alignment claw 53a and the centering case 51 and the alignment claw 53a in the opening hole 51c. Two gap insertion portions 63b that are inserted into the gap, three side surface forming portions (not shown) that are formed on the inner surface of the gap insertion portion 63b and that respectively form the three side shapes of the alignment claws 53a, and the opening holes 51c. A stepped portion 63c that provides a step on the periphery thereof.

  The upper surface forming portion 63 a is provided so as to have a shape along the first inclined surface 53 a 1, the second inclined surface 53 a 2, and the upper surface of the connecting portion 53 of the alignment claw 53 a. In addition, a curved surface is formed at a position continuous from the upper surface forming portion 53a to the side surface forming portion. Thereby, the periphery of the alignment nail | claw 53a can be made into a curved surface shape (R shape).

  Further, the stepped portion 63c is formed in the second upper mold 63, whereby stepped portions 51a1 and 51b1 in which the peripheral edge of the opening hole 51c is lowered are formed.

  Further, the gap insertion portion 63b contacts the inner peripheral surface of the peripheral edge of the opening hole 51c and the side surface of the alignment claw 53 that opposes the inner peripheral surface in the circumferential direction. Therefore, when the centering case 51 is produced in large quantities, the gap insertion part 63b contacts the side surface of the alignment claw 53a and the inner peripheral surface of the peripheral edge of the opening hole 51c by the number of production of the centering case 51. As a result, there is a possibility that a part of the contact portion of the gap insertion portion 63b is worn. The gap insertion portion 63b, which is partially worn, separates the second upper mold 63 from the lower mold 62 in the axial direction, so that the inner peripheral surface of the peripheral edge of the opening hole 51c and the side surface of the alignment claw 53a are released. There is a possibility that burr portions 55 and 56 occur at the upper end.

  However, a curved surface shape is formed between the upper surface forming portion 63 a and the side surface forming portion 63 c of the second upper mold 63, so that a curved surface shape can be formed on the periphery of the alignment claw 53. Therefore, the burr 55 generated by the worn second upper mold 63 can be prevented from projecting outward from the outer surface of the alignment claw 53. The second upper mold 63 is formed with a stepped portion 63c so that the second mold 63 is released on the upper side in the axial direction on the upper surface of the peripheral edge of the opening hole 51c (that is, the upper surface of the stepped portions 51a1 and 51b1). It is possible to prevent the upper end position of the burr portion 56 that is sometimes generated from being outside the outer surfaces of the cylindrical portion 51a and the conical portion 51b.

  As mentioned above, although one form of the Example of the chucking apparatus of this invention and the brushless motor carrying this chucking apparatus was demonstrated, this invention is not limited to this, In a claim, various deformation | transformation are carried out. Is possible.

  In the contact avoidance portion of the present invention, a chamfered portion is provided in the accommodation opening portion 31d, a curved shape (R shape) is provided in the alignment claws 31c and 53, and a step portion is provided in the opening hole 51c, but the present invention is not limited thereto. The contact avoiding portion may have a structure in which the upper end surface of the burr portion generated at each portion does not contact the disk. Further, the chamfered portion, the curved surface shape, and the stepped portion may be applied to each of the accommodation opening 31d, the alignment claws 31c and 53, and the opening hole 51c.

  In the embodiment of the present invention, the centering cases 31 and 51 are the chucking devices 30 and 50 in which only the alignment claws 31c and 53 are formed. However, the present invention is not limited to this. For example, in a so-called ball chuck type chucking device in which a claw member that presses the disk from the upper side and urges it radially outward is movable in the radial direction by an elastic member, the alignment claw as in the present invention is provided. Even if formed, the same effect is obtained.

  Further, as shown in FIG. 15, the alignment pawl 70 itself may be formed below the conical portion 71a of the centering case 71 in the axial direction to form a contact avoiding portion that avoids contact with the disk. With this structure, even if a burr portion is generated on the axially upper side in the connecting portion 70a and the aligning portion 70b of the alignment claw 70, the conical portion 71a is provided on the axially upper side with respect to the alignment claw 70. Since the disc contacts only the conical portion 71a, contact between the burr portion and the disc can be prevented.

It is the schematic cross section cut in the axial direction which shows one form of the Example of the brushless motor of this invention. It is the top view seen from the upper side which shows one form of the Example of the chucking apparatus of this invention. FIG. 3 is a schematic cross-sectional view of FIG. 2 cut in the axial direction, showing the chucking device of the present invention. It is the perspective view which expanded the alignment nail | claw of the chucking apparatus of this invention. It is an expanded sectional view which shows the relationship between the burr | flash which generate | occur | produces in the metal mold | die in the chucking apparatus of this invention, and a curved surface part and a chamfering part. It is a schematic cross section which shows the metal mold | die which shape | molds the chucking apparatus of this invention. It is the perspective view which expanded the part which showed the 2nd metal mold | die in the metal mold | die which shape | molds the chucking apparatus of this invention. It is the schematic cross section which cut the accommodation opening part in the metal mold | die which shape | molds the chucking apparatus of this invention in the radial direction. It is the top view seen from the upper mold | type which shows the other Example of the chucking apparatus of this invention. FIG. 10 is a schematic cross-sectional view of FIG. 9 taken in the axial direction showing the chucking device of the present invention. It is the perspective view which expanded the alignment nail | claw of the chucking apparatus of FIG. FIG. 10 is an enlarged cross-sectional view showing a relationship between a burr generated in a mold in the chucking device of FIG. 9 and a step portion and a curved surface portion. It is a schematic cross section which shows the metal mold | die which shape | molds the chucking apparatus of FIG. FIG. 10 is a schematic cross-sectional view in which a centering claw in a mold for molding the chucking device of FIG. 9 is cut in a radial direction. It is a perspective view which shows the other Example of the alignment nail | claw periphery of the chucking apparatus of this invention. It is the top view seen from the upper side which shows the conventional chucking apparatus. It is the expanded schematic cross section which cut the alignment nail | claw in the radial direction which shows the conventional chucking apparatus. It is the enlarged view which showed a part of metal mold | die which shape | molds the conventional chucking apparatus. It is an enlarged view which shows the state which extracted the metal mold | die of FIG.

Explanation of symbols

11 Rotor magnet 12 Shaft 21 Armature 23 Sleeve (bearing part)
30, 50 Chucking device 31 Centering case 31a1, 31b1 Chamfer 31c Alignment claw 31c11, 31c21 Curved surface 31d Storage opening 32 Mounting part 33 Radial extension part (extension part)
35, 36 Burr 40, 60 Die 51 Centering cases 51a1, 51b1 Step 51c Opening hole (accommodating opening)
52 Placement part 53 Radial extension part 53a Alignment claw 53a11, 53a21 Curved surface part 55, 56 Return part J1 Rotating shaft (central axis)

Claims (8)

In a chucking device that makes a disk-shaped disc having a central opening detachable from one side with respect to the central axis of the rotating mounting portion,
A substantially cylindrical centering case through which the central opening of the disk-shaped disc is inserted;
An alignment claw having an alignment function that abuts at least the inner peripheral edge of the center opening and acts to match the radial center of the disc-shaped disc and the radial center of the centering case;
With
The centering case and the aligning claw are integrally molded with a resin material using a mold,
The centering case has an accommodating opening for accommodating the alignment claw,
A contact avoidance portion that avoids contact between the burr portion generated on the one side when the mold is released and the inner peripheral surface of the disk-shaped disc is formed on the periphery of the housing opening. A featured chucking device. The chucking device according to claim 1, wherein the contact avoiding portion is formed by forming a peripheral edge of the accommodation opening portion into a chamfered shape or a curved shape. The chucking device according to claim 1, wherein the contact avoiding portion is formed as a stepped portion having an inner side of the periphery on the lower side in the axial direction at a periphery of the accommodation opening. In a chucking device that makes a disk-shaped disc having a central opening detachable from one side with respect to the central axis on a rotating mounting surface,
A centering case formed in the substantially cylindrical shape and through which the central opening of the disk-shaped disc is inserted;
An alignment claw having an alignment function that abuts at least the inner peripheral edge of the center opening and acts to match the radial center of the disc-shaped disc and the radial center of the centering case;
With
The centering case and the aligning claw are integrally molded with a resin material using a mold,
The centering case has an accommodating opening for accommodating the alignment claw,
A contact avoidance portion that avoids contact between the burr portion generated on the one side when releasing the mold and the inner peripheral surface of the disk-shaped disc is formed on the periphery of the alignment claw. A featured chucking device. The chucking device according to claim 4, wherein the contact avoiding portion is formed by forming a peripheral edge of the alignment nail into a chamfered shape or a curved shape. The alignment nail is
A connecting portion for connecting the alignment portion and the centering case;
The contact avoiding portion is formed as a contact avoiding portion by being formed so that the connecting portion is positioned radially inward and axially downward with respect to an outer surface of the centering case. The chucking device according to claim 5. The centering case has an extending portion that extends radially outward to connect to the mounting portion,
The accommodation opening is formed to the outer peripheral side of the extension part,
The centering claw has a centering portion that extends radially inward from one surface on the outer peripheral side of the housing opening, and extends upward in the axial direction at substantially the same position as the centering case connected to the extension. The chucking device according to claim 1, wherein the chucking device is provided. A shaft serving as a rotation axis;
A rotor magnet that rotates integrally with the shaft;
An armature facing the rotor magnet via a gap;
A chucking device according to any one of claims 1 to 7,
A brushless motor with
The brushing motor is characterized in that the chucking device is arranged coaxially with the shaft and is arranged axially above the armature.

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