JP2010231877A - Chucking apparatus, motor unit and disk driving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize chucking performance of a chucking apparatus. <P>SOLUTION: The chucking apparatus 40 includes a mounting section 44 arranged around a center axis J1 and mounted with a disk having a center hole; a plurality of claw members 42, formed by a resin injection molding and radially disposed around the center axis outward in the radial direction at the inside of the mounting section; an energizing section 43 for energizing the plurality of claw members radially outward; and a center case 41 for housing the plurality of claw members, while their distal ends are projected, wherein the plurality of claw members turns so that their tips move vertically, when the disk is mounted and also moves in a radial direction. The chucking apparatus further includes a slide contact surface, where each of the plurality of claw members comes in slide contact with a guiding section of the center case when the disk is mounted; and a clearance section 7, of which at least a part is a hole section or notched section positioned within a range in the radial direction where the slide contact surface exists. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a chucking device for fixing a disk having a central hole.

  Conventionally, a chucking device that detachably holds a disc such as a DVD (digital versatile disc) or a CD (compact disc) has been used in a disc drive. The chucking device is attached to the rotor portion of the motor, and the disk rotates together with the rotor portion.

  A general chucking device has a plurality of pawl members that are arranged radially about the central axis of the motor and are biased outward by a spring. The disk is fixed on the mounting surface by the claw member coming into contact with the edge of the center hole of the disk and pressing the edge outward and downward. When the disc is mounted on the chucking device, the disc is pressed against the mounting surface, so that the plurality of claw members are pushed by the lower surface of the disc and the inner surface of the center hole to temporarily move inside the center hole of the disc. To do. When the disc passes through the tip of the claw member and is placed on the placement surface, the tip of the claw member protrudes from the top surface of the disc.

Japanese Patent Application Laid-Open No. 2003-59144 discloses a motor having a disk clamp mechanism. In the paragraph 0036, “the disk holding ring assembly 10 is composed of three components: a disk holding ring 7, disk clamp claws 8 a, 8 b, 8 c and springs 9 a, 9 b, 9 c. It performs the function of positioning in the direction. "
JP 2003-59144 A

  By the way, the claw member of the chucking device may be formed into a three-dimensionally complicated shape with resin. A difference in the thickness of the resin may cause a difference in the cooling rate, which may cause shrinkage or dents during injection molding. If sinking occurs on the part of the claw member that contacts the disk or the part that slides for chucking, the chucking performance may be reduced by affecting the disk attachment / detachment operation or the disk holding force. . In particular, when a plurality of claw members are manufactured at one time using a set of molds, there are cases where the degree of sinking becomes noticeable due to resin flow in the mold and non-uniformity in the mold temperature distribution.

  The main object of the present invention is to stabilize the chucking performance of the chucking device.

  An exemplary chucking device according to the present invention is arranged around a central axis, and is formed by a placement portion on which a disc having a central hole is placed, and is formed by injection molding of resin, and is placed inside the placement portion. A plurality of claw members arranged radially about the central axis toward the radially outward direction, a biasing portion that urges the plurality of claw members outward in the radial direction, and the plurality of claws A center case that houses the member with its tip protruding, and each of the plurality of claw members rotates so that the tip moves up and down and moves in the radial direction when the disk is placed. Each of the plurality of claw members is at least partially located in a radial range in which the sliding contact surface exists, and at least a part of the sliding contact surface that is in sliding contact with the guide portion of the center case when the disk is placed. And a Nusumi part that is a hole or notch .

  In the present invention, the chucking performance can be stabilized by preventing the claw member from sinking.

FIG. 1 is a longitudinal sectional view of a disk drive device. FIG. 2 is a longitudinal sectional view of the motor unit. FIG. 3 is an enlarged view of the chucking device. FIG. 4 is a plan view of the chucking device. FIG. 5 is a plan view of the claw member. FIG. 6 is a longitudinal sectional view of the claw member. FIG. 7 is a rear view of the claw member. FIG. 8 is an enlarged view of the tip of the claw member. FIG. 9 is a longitudinal sectional view of the chucking device. FIG. 10 is a diagram illustrating the operation of the claw member. FIG. 11 is a diagram illustrating the operation of the claw member. FIG. 12 is a diagram illustrating the operation of the claw member. FIG. 13 is a longitudinal sectional view of the claw member. FIG. 14 is a diagram illustrating a state of manufacturing the claw member. FIG. 15 is a plan view of a claw member according to another example. FIG. 16 is a longitudinal sectional view of the claw member. FIG. 17 is a longitudinal sectional view of a claw member according to still another example. FIG. 18 is a plan view of a claw member according to still another example. FIG. 19 is a front view of the claw member. FIG. 20 is a side view of the claw member. FIG. 21 is a longitudinal sectional view of the claw member. FIG. 22 is a diagram illustrating the operation of the claw member. FIG. 23 is a diagram illustrating the operation of the claw member according to still another example. FIG. 24 is a diagram illustrating the operation of the claw member according to still another example. FIG. 25 is a diagram illustrating the operation of the claw member.

  In the present specification, in the direction of the central axis J1, the upper side in the figure is simply called “upper side”, and the lower side in the figure is simply called “lower side”. The expressions “upper” and “lower” do not necessarily coincide with the direction of gravity.

  FIG. 1 is a longitudinal sectional view of a disk drive device 50 according to an embodiment of the present invention. The disk drive device 50 includes a motor unit 1, an access unit 51, and a box-shaped housing 52 that holds these configurations inside. The motor unit 1 rotates a disk 9 for recording information. The access unit 51 includes a head 511 and a head moving mechanism 512. The head 511 is an optical pickup mechanism that reads and / or writes information on the disk 9. The head moving mechanism 512 moves the head 511 with respect to the motor unit 1 and the disk 9. The head 511 includes a light emitting unit that emits laser light toward the lower surface of the disk 9 and a light receiving unit that receives reflected light from the disk 9. The housing 52 has a lid 521 at the top that opens and closes when the disk 9 is attached to and removed from the disk drive device 50.

  In the disk drive device 50, the disk 9 is fixed by fitting the center hole 91 of the disk 9 into the chucking device 40 attached to the upper side of the motor unit 1. With the drive of the motor unit 1, the head 9 moves to the required position in the radial direction while the head 9 moves while the disk 9 rotates, so that information is read from and / or written to the head 511. Done.

  FIG. 2 is a longitudinal sectional view of the motor unit 1. The disk rotating motor unit 1 includes an electric motor 10 and a chucking device 40 that detachably fixes the disk 9. The motor 10 has a rotor part 20 and a stator part 30. The rotor unit 20 is a rotating unit that rotates about the central axis J1. The stator part 30 supports the rotor part 20 rotatably. The chucking device 40 is attached to the upper end of the rotor unit 20, that is, the side opposite to the stator unit 30. In the following description, the radial direction centered on the central axis J1 is simply referred to as “radial direction”, the circumferential direction centered on the central axis J1 is simply referred to as “circumferential direction”, and the direction parallel to the central axis J1 is simply referred to as “circumferential direction”. Called the “axial direction”.

  The rotor unit 20 includes a shaft 21 and a rotor holder 22. The shaft 21 has a substantially cylindrical shape centered on the central axis J1. The rotor holder 22 is fixed to the upper part of the shaft 21. The rotor holder 22 has a shaft fixing portion 221, an annular portion 222, and a cylindrical portion 223. The shaft fixing part 221 has a cylindrical shape, and the shaft 21 is fitted therein. The annular portion 222 extends radially outward from the lower portion of the shaft fixing portion 221. The cylindrical portion 223 has a cylindrical shape and extends downward from the outer peripheral edge of the annular portion 222. The annular field magnet 23 is fixed to the inner peripheral surface of the cylindrical portion 223 by adhesion.

  The annular portion 222 includes an outer annular portion 2222 to which the cylindrical portion 223 is connected, and an inner annular portion 2221 positioned above the outer annular portion 2222. A retaining member 24 is fixed to the lower surface of the outer annular portion 2222. The retaining member 24 has a plurality of protrusions 241 extending inward in the radial direction. The number of protrusions 241 is, for example, three. The rotor holder 22 is formed, for example, by pressing a thin plate made of a magnetic material.

  The stator unit 30 includes a substantially cylindrical sleeve 31, a bearing bush 32, a plate 33, and a thrust plate 34. The sleeve 31 supports the shaft 21 rotatably. The bearing bush 32 has a hollow hole into which the sleeve 31 is inserted. The plate 33 closes the lower side of the hollow hole of the bearing bush 32. The thrust plate 34 is disposed on the inner bottom surface of the plate 33 and supports the shaft 21 in the axial direction by contacting the lower end of the shaft 21. The stator unit 30 further includes a stator 35, a circuit board 36, and a mounting plate 37. The stator 35 is disposed around the bearing bush 32. The circuit board 36 is disposed below the stator 35. The mounting plate 37 is fixed to the bearing bush 32.

  The sleeve 31 is made of an oil-containing sintered metal. The inner peripheral surface of the sleeve 31 serves as a bearing surface that supports the outer peripheral surface of the shaft 21 via lubricating oil. The bearing bush 32 has a cylindrical portion 321 and a stator fixing portion 322. The cylindrical portion 321 fixes the sleeve 31. The stator fixing portion 322 extends radially outward from the lower portion of the cylindrical portion 321. The stator 35 is fixed to the stator fixing portion 322 by adhesion. An inner protrusion 323 and an outer protrusion 324 are formed on the lower surface of the bearing bush 32. The inner protrusion 323 fixes the plate 33. The outer protrusion 324 is disposed radially outside the inner protrusion 323 and fixes the mounting plate 37.

  A flange portion 3211 protruding outward in the radial direction is formed at the upper end portion of the cylindrical portion 321. The protruding portion 241 of the retaining member 24 is located below the flange portion 3211. The edge on the central axis J1 side of the protruding portion 241 is located on the radially inner side with respect to the outer peripheral edge of the flange portion 3211. Thereby, even if the rotor part 20 moves upward, the upper surface of the projection part 241 comes into contact with the lower surface of the flange part 3211 so that the movement is restricted. An annular preload magnet 25 is provided on the upper surface of the bearing bush 32. The preload magnet 25 is opposed to the retaining member 24 in the axial direction and generates a magnetic attractive force between the retaining member 24.

  The stator 35 includes a core 351. The core 351 is formed by stacking a plurality of thin magnetic steel plates in the vertical direction. The core 351 includes an annular core back portion 3511 and a plurality of teeth portions 3512. The teeth part 3512 extends radially outward from the core back part 3511 in the radial direction. The coil 352 is formed by winding a conductive wire around each tooth portion 3512 in multiple layers. In the motor 10, a current is passed through the coil 352 from an external power supply (not shown) to generate torque between the coil 352 and the field magnet 23, and the rotor unit 20 rotates about the central axis J1. Of course, the motor 10 may be an inner rotor type in which field magnets are arranged inside the stator.

  FIG. 3 is an enlarged view of the chucking device 40 attached to the motor unit 1, and shows only the right side from the central axis J1. FIG. 4 is a plan view of the chucking device 40.

  The thin chucking device 40 includes a center case 41, a plurality of claw members 42, an elastic member 43, and an annular placement portion 44. The center case 41 has a hollow and thick disc shape centered on the central axis J1. The plurality of claw members 42 protrude outward from the center case 41. The elastic member 43 is a biasing portion that is housed in the center case 41 and biases each claw member 42 radially outward. The mounting portion 44 is positioned around the center case 41 around the central axis J1, and the disk 9 (see FIG. 1) is mounted on the mounting portion 44. The number of claw members 42 is three in the present embodiment. As will be described later, when the disk 9 is mounted, the lower surface of the disk 9 abuts on an annular mounting surface 441 that is the upper surface of the mounting portion 44 and that is centered on the central axis J1. In this embodiment, a coil spring is used as the elastic member 43, but other members may be used as long as they have elasticity and can urge the claw member 42.

  As shown in FIG. 3, the center case 41 includes a thick, substantially cylindrical base portion 411 and an annular lid portion 412. A shaft fixing portion 221 is inserted into the base portion 411. The lid portion 412 extends radially outward from the base portion 411. As shown in FIG. 4, the center case 41 further includes a peripheral wall portion 414. The peripheral wall portion 414 has a wall shape that extends downward from the outer peripheral edge of the lid portion 412 and surrounds the central axis J1 inside the placement surface 441.

  In the peripheral wall portion 414, a plurality of openings 413 are formed at equal angular intervals in the circumferential direction around the central axis J1. In the present embodiment, three openings 413 are provided at intervals of 120 degrees. A claw member 42 is disposed in each opening 413 with the tip directed radially outward. Thereby, the front-end | tip of the some nail | claw member 42 arrange | positioned radially centering on the central axis J1 inside the mounting surface 441 protrudes from the some opening part 413 of the surrounding wall part 414, respectively.

  A centering claw 415 is provided between the two adjacent openings 413 in the peripheral wall 414. When the disk 9 is fixed by the chucking device 40, the center axis J1 of the chucking device 40 and the center axis of the disk 9 are brought into contact with the center hole 91 of the disk by the tip of the alignment claw 415 coming into contact with the center hole 91 of the disk. Match and align.

  As shown in FIG. 3, a substantially cylindrical protrusion 4111 that protrudes radially outward is formed at the lower portion of the base 411. One end of the elastic member 43 is fitted into the protrusion 4111. A substantially cylindrical nail-side protrusion 424 that protrudes radially inward is formed at the lower portion of the claw member 42. The other end of the elastic member 43 is fitted into the claw-side protrusion 424. A support portion 416 is provided below the claw member 42 of the opening 413. The support portion 416 supports the claw member 42 from below.

  FIG. 5 is a plan view of the claw member 42. The right side of the claw member 42 in FIG. FIG. 6 is a longitudinal sectional view of the claw member 42 at the position indicated by the arrow A in FIG. FIG. 6 shows a cross section of the surface including the center axis J1 and the contact position between the center hole 91 and the tip of the claw member 42 when the disk 9 is placed. As shown in FIGS. 5 and 6, the claw member 42 includes a claw body 421 and two blade parts 422. The claw body 421 contacts the disk 9 when the disk 9 is fixed to the chucking device 40. The two blade portions 422 extend from the circumferential ends of the claw portion main body 421 toward the radially inward direction, respectively. 5 and 6, the claw member 42 is rotatable around an end 4214 that is radially inward of the upper surface of the claw body 421. For how the claw member 42 rotates, see FIGS. 9 to 12 to be described later.

  The distal end portion 423 is a portion farthest from the central axis J1 of the claw portion main body 421. The front end portion 423 has a curved shape that protrudes toward the center hole 91 of the disk 9 when viewed in plan. The radius of curvature of the tip 423 in plan view is smaller than that of the center hole 91. The tip 423 contacts the edge or inner surface of the center hole 91 of the disk 9 at the center. An upper surface 4234 of the claw body 421 is substantially perpendicular to the central axis J1. Surfaces 4234a, which are portions on both sides in the circumferential direction of the upper surface 4234, are located slightly below the central portion. In other words, the central portion of the upper surface 4234 is slightly convex upward.

  The claw member 42 has a symmetrical shape with the cross section at the position indicated by the arrow A in FIG. As shown in FIG. 6, a groove 4211 extending along the radial direction is formed on the lower side of the claw body 421. The bottom surface 4212 of the groove 4211 is an inclined surface whose normal is inclined with respect to the central axis J1. The bottom surface 4212 is separated from the central axis J1 as it goes upward.

  As shown in FIGS. 5 and 6, the radially inner side surface 426 of the claw body 421 functions as a contact portion with which the elastic member 43 of FIG. 3 contacts. Hereinafter, the side surface 426 is referred to as a “contact portion 426”. Normally, a part of the outer peripheral surface 4241 of the claw-side protrusion 424 also contacts the elastic member 43. The claw part main body 421 further includes a scum part 7 located above the claw side protrusion 424. The Nusumi part 7 is a hole that is recessed radially outward from the contact part 426 of the claw part body 421, and the inner surface 71 of the Nusumi part 7 is continuous from the contact part 426. Further, as shown in FIG. 3, the Nusumi part 7 extends outward in the radial direction from the elastic member 43 and the support part 416.

  As shown in FIG. 6, the lower portion of the inner surface 71 of the ridge portion 7 is directed upward as it is away from the central axis J <b> 1, and the ridge portion 7 has a tapered shape in which the axial width gradually decreases outward in the radial direction. It has become. The bottom surface 4212 of the groove part 4211 is also directed upward as it is away from the central axis J1.

  FIG. 7 is a rear view of the claw member 42. The width | variety of the Nusumi part 7 in the circumferential direction is smaller than the width | variety of the contact part 426, and the Nusumi part 7 is located inside the contact part 426 in the circumferential direction. Furthermore, in the contact part 426, as shown by a two-dot chain line, a region 81 corresponding to the outer diameter of the elastic member 43, that is, a region surrounded by the outer diameter of the elastic member 43 when viewed from the inside in the radial direction. The lower part of the inner surface 71 of the Nusumi part 7 is located inside. Thereby, the area | region on the nail | claw member 42 can be used effectively compared with the case where the Nusumi part 7 is provided away from the nail | claw side protrusion part 424, and the height of the nail | claw member 42 can be made low. As shown in FIG. 6, in the claw member 42, the thickness portion 7 is provided, so that the portion near the top surface 4234, the tip portion 423, and the portion near the bottom surface 4212 are thinned.

  FIG. 8 is an enlarged view showing a cross section in the vicinity of the tip 423 of the claw member 42. The distal end portion 423 has a distal end surface 4231 facing the right side in FIG. 8 that is radially outward. The front end surface 4231 is located above the bottom surface 4212 of the groove 4211 shown in FIG. As shown in FIG. 8, the cross section of the front end surface 4231 is linear. An inclined lower surface 4232 is located below the distal end surface 4231. The inclined lower surface 4232 approaches the central axis J1 as it goes downward, in other words, moves away from the placement surface 441 shown in FIG. 3 as it moves away from the central axis J1. Between the front end surface 4231 and the inclined lower surface 4232, a lower side chamfered shape surface 4233 having a curved shape that is convex outward in the radial direction in the cross section is located. The curvature radius of the lower side chamfered shape surface 4233 indicated by the symbol R1 is not less than 0.1 mm and not more than 0.2 mm. On the upper side of the front end surface 4231, a linear upper surface 4234 whose cross section is perpendicular to the central axis J1 extends inward in the radial direction. Between the upper surface 4234 and the front end surface 4231, an upper side chamfered shape surface 4235 that protrudes substantially upward in the cross section is located. The curvature radius of the upper side chamfered shape surface 4235 indicated by the reference symbol R2 is 0.1 mm or more and 0.3 mm or less.

  The front end surface 4231, the lower side chamfered shape surface 4233, and the inclined lower surface 4232 are smoothly connected. The point where the normal line of the lower side chamfered shape surface 4233 is parallel to the normal line of the front end surface 4231 in the cross section is regarded as the boundary between the front end surface 4231 and the lower side chamfered shape surface 4233, and this boundary is hereinafter referred to as the front end surface. This is called the “lower end 4231a” of 4231. Similarly, the point at which the normal line of the lower side chamfered shape surface 4233 and the normal line of the inclined lower surface 4232 are parallel is defined as the boundary between the lower side chamfered shape surface 4233 and the inclined lower surface 4232. The distal end surface 4231, the upper side chamfered shape surface 4235, and the upper surface 4234 are also smoothly connected. A point at which the normal line of the tip surface 4231 and the normal line of the upper side chamfered shape surface 4235 are parallel to each other in the cross section is regarded as the boundary between the front end surface 4231 and the upper side chamfered shape surface 4235. This is referred to as “the upper end 4231b”. The point at which the normal line of the upper side chamfered shape surface 4235 and the normal line of the upper surface 4234 are parallel is also defined as the boundary between the upper side chamfered shape surface 4235 and the upper surface 4234.

  In the distal end portion 423, the distal end surface 4231 is inclined so as to approach the central axis J1 as it goes upward along the central axis J1. The lower end 4231a of the distal end surface 4231 is farther from the central axis J1 than the upper end 4231b of the distal end surface 4231.

  FIG. 9 is a longitudinal sectional view of the chucking device 40 in a state where the disk 9 is not mounted. In FIG. 9, illustration of the elastic member 43 is omitted. The same applies to the following similar drawings. The lower surface of each blade portion 422 of the claw member 42 has a substantially spherical shape or a cylindrical surface whose central axis is perpendicular to the radial direction and horizontal. Each claw member 42 in the chucking device 40 contacts the upper surface of the annular portion 222 of the rotor holder 22 at the lower surface of the two blade portions 422. The claw member 42 is urged outward in the radial direction by the elastic member 43. In a state where the disk 9 is not placed on the placement surface 441, the abutment surface 4161 of the support portion 416 abuts on the locking surface 4213 of the lower portion in the radial direction of the claw member 42, thereby The radially outward movement is locked.

  Next, the operation of the chucking device 40 will be described. 10 to 12 are views for explaining the operation of the claw member 42 when the disk 9 is mounted on the chucking device 40. FIG. When the disk 9 is placed on the placement surface 441, first, the lower edge of the center hole 91 of the disk 9 comes into contact with the upper surface 4234 of the claw member 42 as shown in FIG. The contact position of the disk 9 on the claw member 42 is not constant. In FIG. 10, the position of the disk 9 when the inner surface of the center hole 91 is in light contact with the tips of the other two claw members is indicated by a two-dot chain line. It shows. That is, the contact position between the disk 9 and the upper surface 4234 indicated by a two-dot chain line is the position on the innermost side in the radial direction of the region where the upper surface 4234 and the disk 9 may contact each other.

  When the disk 9 comes into contact with the upper surface 4234, a downward force is applied to the claw body 421, and the inner edge portion in the radial direction of the surface 4234a shown in FIG. While the lower surface of the blade portion 422 is in sliding contact with the annular portion 222 around the contact point, the tip end portion 423 rotates slightly clockwise in FIG. 10 and approaches the placement surface 441. The support portion 416 is a protruding portion that protrudes upward. The claw member 42 moves inward in the radial direction while the bottom surface 4212 of the groove portion 4211 is in sliding contact with the upper end of the support portion 416 that is the guide portion. Hereinafter, the bottom surface 4212 is referred to as a “sliding contact surface 4212”. That is, in the chucking device 40, when the disk 9 is placed on the placement surface 441, the protruding portion that is the support portion 416 functions as a guide portion that guides the movement of the claw member 42 inward in the radial direction. To do.

  As described above, since the lower surface of the blade portion 422 is substantially spherical or cylindrical, the contact area between the blade portion 422 and the annular portion 222 is small, and the claw member 42 when the disk 9 is placed The frictional force between the annular portion 222 is reduced. Moreover, the frictional force between the groove part 4211 and the support part 416 is also reduced. Accordingly, the claw member 42 can be smoothly moved inward in the radial direction, and the force for pushing the disk 9 downward in the axial direction can be reduced.

  As shown in FIG. 11, when the tip end portion 423 of the claw member 42 moves to the inside of the center hole 91 of the disc 9, the disc 9 is placed on the placement portion 44 while the tip end portion 423 contacts the inner peripheral surface of the center hole 91. To the vicinity of the mounting surface 441. Thereafter, when the disc 9 is placed on the placement surface 441 while the center is aligned with the center axis J1 by the alignment claw 415 shown in FIG. 4, the leading end 423 is positioned on the upper side of the disc 9 as shown in FIG. Escape to. The claw member 42 is pushed by the elastic member 43 and returned radially outward, and the inclined lower surface 4232 of the claw member 42 contacts the upper edge 911 of the center hole 91 of the disk 9. As a result, the edge 911 is pressed outward by the claw member 42, and a force toward the mounting surface 441 is also applied to the disk 9 by the inclined lower surface 4232, so that the disk 9 is fixed on the mounting surface 441. As shown in FIG. 8, the lower side chamfered shape surface 4233 and the upper side chamfered shape surface 4235 are formed at the front end portion 423, so that the mounting surface 441 is temporarily approached from FIG. 10 to FIG. 12. The tip 423 of the claw member 42 can pass through the center hole 91 of the disk 9 smoothly.

  As described above, in the chucking device 40, when the disc 9 is placed on the placement surface 441, the tip portion 423 of the claw member 42 is rotated so as to move up and down and moves in the radial direction. Thus, the disk 9 is fixed to the chucking device 40 with high accuracy.

  Next, the size of the Nusumi part 7 will be described. The shape of the claw member 42 is complicated, and when the nuisance part 7 is not provided, the thickness of the claw member 42 varies depending on the part. Although it is difficult to define the thickness of the claw member 42 strictly, for example, the thickness of a certain part can be defined as the diameter of the largest sphere included in the part.

  When there are various thicknesses in the claw member 42, uniform cooling does not occur when the claw member is formed by resin injection molding, and sink marks in which the thickness decreases at the thick portion occur. On the other hand, in the claw member 42 shown in FIG. 5 and FIG. 6, since a deep recess is formed so as to go inside the claw body 421, the upper part near the upper surface 4234, the lower part near the tip part 423 and the groove part 4211. And the difference in thickness is also reduced. As a result, the thickness is made uniform, and sink marks at the time of injection molding are prevented in the entire nail portion main body 421. The effect of “sink prevention” includes suppression of sink marks.

  Here, in order to stabilize the chucking performance of the chucking device 40, in the operation described with reference to FIGS. 10 to 12, the sink at the position where the claw member 42 is in sliding contact with another member is reduced or prevented. Is important. 10 and 11, the upper surface 4234 and the front end portion 423 are in contact with the disk 9, and the sliding contact surface 4212 of the groove portion 4211 is in contact with the support portion 416. In FIG. 12, the inclined lower surfaces 4232 on both sides of the groove 4211 abut against the disk 9. From the above, it is preferable that the Nusumi portion 7 is formed deeper outside in the radial direction than these contact positions.

  Specifically, the position on the upper surface 4234 is the innermost position in the radial direction of the region that may be in contact with the disk 9, that is, the diameter is larger than the contact position between the disk 9 and the upper surface 4234 indicated by a two-dot chain line in FIG. It is preferable that the Nusumi part 7 is formed to the outside in the direction. Further, when attention is paid to the sliding contact surface 4212 of the groove portion 4211, the radial direction of the sliding contact surface 4212 with the central axis J1 as the center, as indicated by a two-dot chain line in FIG. Part of the Nusumi part 7 overlaps in a plan view in a range between two virtual cylindrical surfaces 991 and 992 passing through the inner end and the radially outer end. That is, a part of the Nusumi portion 7 overlaps the range H1 in the radial direction where the sliding contact surface 4212 exists in a plan view. Accordingly, the occurrence of a depression due to resin sink marks on the sliding contact surface 4212 is prevented, and the support portion 416 of FIG. 10 is prevented from fitting into the depression. As a result, a reduction in chucking performance is prevented.

  More preferably, the Nusumi portion 7 is formed to the radially outer side from the most radially inner position of the region that may come into contact with the support portion 416 on the sliding contact surface 4212. That is, as shown in FIG. 9, in the state before the disk 9 is placed, the end portion on the radially outer side of the Nusumi portion 7 is a plan view than the contact position 89 between the sliding contact surface 4212 and the support portion 416. In the radial direction. Thereby, the fall of a chucking performance is prevented more reliably.

  Thus, it is preferable that the Nusumi part 7 is formed deeply, and it is preferable to have at least half the length of the claw part main body 421 in the radial direction. Moreover, it is preferable to provide so that the thickness of the thick part in case the Nusumi part 7 is not formed may be halved. In the claw member 42, as described above, the sliding contact surface 4212 shown in FIG. 6 and the lower portion of the inner surface 71 of the Nusumi portion 7 are directed upward as they move away from the central axis J1, so the sliding contact surface 4212 and the The thickness of the part between the part 7 becomes substantially equal. As a result, the occurrence of sink marks on the sliding contact surface 4212 can be further reduced.

  Further, as shown in FIG. 13, a part of the inclined lower surface 4232 is located in the radial range H1 where the sliding contact surface 4212 exists on both sides of the sliding contact surface 4212 in the circumferential direction. The entire inclined lower surface 4232 may be located within the range H1. In the claw member in which the inclined lower surface and the sliding contact surface are provided close to each other, the thickness is increased. However, in the claw member 42, the thickness 7 can be reduced due to the provision of the Nusumi portion 7. Generation can be reduced.

  FIG. 14 is a diagram showing a state of manufacturing the claw member 42, and shows a longitudinal section at the same position as in FIG. The claw member 42 is formed as one member by injection molding of a resin material such as polyacetal. When the claw member 42 is manufactured, the first mold 61 and the second mold 62 are used. Although only one claw member 42 is shown in FIG. 14, the spaces of the plurality of claw members 42 are actually formed by the first mold 61 and the second mold 62, and the plurality of claw members 42 are formed by one injection molding. Manufactured. The first mold 61 has a surface corresponding to most of the upper surface 4234 of the claw member 42 and a radially outer surface. The second mold 62 has a surface corresponding to a part of the upper surface 4234 of the claw member 42 and a radially inner surface. The mold matching surface which is the parting line 63 is located in the vicinity of the connection portion between the claw portion main body 421 and the blade portion 422.

  When the claw member 42 is manufactured, as shown in FIG. 14, in a state where the first mold 61 and the second mold 62 are combined, resin is injected from a gate (not shown) into the mold. Filled. When the filled resin is solidified, the first mold 61 and the second mold 62 move relatively in the radial direction and away from each other, and the claw member 42 is taken out. Thus, since the nail | claw member 42 is a shape which can isolate | separate the 1st and 2nd metal mold | dies 61 and 62 in the direction substantially corresponding to radial direction, manufacture of the nail | claw member 42 is performed easily. Moreover, the structure of the 1st metal mold | die 61 and the 2nd metal mold | die 62 is also simplified.

  Since the Nusumi portion 7 has a tapered shape, it is easier to take out the claw member 42 from the first mold 61. Due to the stabilization of the shape by the Nusumi portion 7, it is easy to perform manufacturing by multi-cavity forming a plurality of claw members 42 at a time, and the manufacturing cost can be reduced. The same applies to the following claw members to be described later. Further, since the parting line 63 is formed so as to avoid the radially inner portion of the upper surface 4234, the inclined lower surface 4232, and the sliding contact surface 4212 of the groove 4211, the upper surface 4234, the inclined lower surface 4232, and the sliding contact surface 4212 are highly accurate. To be molded. Since the Nusumi part 7 is a hole that opens radially inward, it prevents the tip part 423 from having an influence on the molding accuracy compared to the case where the Nusumi part is provided at the tip part 423 of the claw member 42. Is done.

  In addition, since the parting line 63 is located in the vicinity of the connection part between the claw part main body 421 and the blade part 422, even if a burr occurs in the parting line 63, the burr affects the chucking performance. Giving is avoided.

  FIG. 15 is a plan view showing another example of the claw member. 16 is a longitudinal sectional view of the claw member 42a at the position indicated by the arrow B in FIG. The claw member 42a is different from the claw member 42 shown in FIGS. The nail | claw part 7a of the nail | claw member 42a is located above the nail | claw side protrusion part 424, and is a notch part extended in radial direction outward from the edge part inside radial direction in the upper part of the nail | claw part main body 421. As in the case of FIGS. 5 and 6, the width of the Nusumi part 7 a in the circumferential direction is smaller than the width of the contact part 426.

  5 and 6, the rugged portion 7 a is also formed on the upper surface 4234 to the radially outer side of the most radially inner position of the region that may come into contact with the disk 9. Is preferred. Further, in the claw member 42a, similarly to FIG. 13, in the state before the disc 9 is placed, the Nusumi portion 7a shown in FIG. 16 is surrounded by two cylindrical surfaces 991 and 992 having the central axis J1 as the center. It overlaps with the range H1 in the radial direction of the sliding contact surface 4212 in a plan view. More preferably, on the slidable contact surface 4212, the urine portion 7a is formed to the radially outer side from the most radially inner position of the region that may come into contact with the support portion 416 of FIG.

  The Nusumi part 7a preferably has a length that is at least half the length of the claw part body 421 in at least the radial direction. Compared to the case where the nosumi part 7 is not formed, the nosumi part 7a is preferably provided so that the thickness of the thick part is halved.

  By satisfying any of these conditions, thinning of the periphery of the smudge portion 7a is realized, and sink marks on the upper surface 4234, the tip portion 423, the sliding contact surface 4212, and the inclined lower surface 4232 can be prevented. Thereby, the chucking performance can be stabilized. In particular, the Nusumi portion 7a overlaps the range H1 in the radial direction of the slidable contact surface 4212 in a plan view, so that a depression due to sink marks is prevented from occurring on the slidable contact surface 4212, and the support portion 416 fits into the dent. Is prevented.

  FIG. 17 is a diagram illustrating still another example of the claw member. The claw member 42b is provided with a crushed portion 7b, which is a groove-shaped cutout that vertically cuts the upper portion of the claw body 421 in the radial direction. As in FIG. 13, the Nusumi portion 7 b overlaps the range in the radial direction of the sliding contact surface 4212 of the groove portion 4211 in a plan view. Thereby, the thickness of the site | part between the Nusumi part 7b and the sliding contact surface 4212 becomes thin, and the sink mark of the resin in the sliding contact surface 4212 is prevented.

  FIG. 18 is a plan view showing still another example of the claw member. 19 is a front view of the claw member 42c, and FIG. 20 is a side view of the claw member 42c. As shown in FIGS. 18 to 20, the claw member 42 c includes a claw part main body 421 and a blade part 422 having shapes different from those of the claw member 42 of FIGS. 5 and 6. The claw body 421 includes a central part 427 and two side parts 428 located on both sides of the central part 427.

  FIG. 21 is a cross-sectional view of the claw body 421 of FIG. The central part 427 includes an inclined lower surface 4232, a pussies 7c, and a substantially cylindrical nail-side protrusion 424. The inclined lower surface 4232 is inclined upward as the distance from the central axis J1 increases. An end portion on the radially outer side of the elastic member 43 shown in FIG. The Nusumi portion 7 c is a cutout portion extending radially outward from the radially inner end at the upper portion of the central portion 427.

  As shown in FIGS. 19 and 20, the two side portions 428 are provided with two slidable contact surfaces 428a that are directed upward as they are separated from the central axis J1. As will be described later, when the disk 9 is fixed, the movement of the claw member 42c is guided by the sliding contact surface 428a coming into contact with the support portion corresponding to the support portion 416 in FIG. Thus, the claw member 42c is a so-called side sliding type claw member. As indicated by a two-dot chain line in FIG. 18, the Nusumi portion 7 c overlaps the radial range H <b> 1 of the sliding contact surface 428 a which is a range surrounded by the two cylindrical surfaces 991 and 992. Here, “overlapping” includes the case where a part of the portion 7c overlaps the range H1.

  As shown in FIG. 21, in the central portion 427, the portion between the humming portion 7 c and the inclined lower surface 4232 becomes thin by providing the murmur portion 7 c. In the claw member not provided with the Nusumi portion, if the resin sink occurs on the inclined lower surface, the resin is biased from the side portion to the central portion, and as a result, the sliding contact surface of the side portion is not accurately formed. In the claw member 42c, the slidable contact surface 428a shown in FIGS. 19 and 20 is accurately formed by providing the scum portion 7c to prevent the occurrence of resin sink on the inclined lower surface 4232.

  FIG. 22 is a cross-sectional view showing the vicinity of the claw member 42 c of the chucking device 40. 22 shows a cross section of the claw member 42c at the position of the arrow D in FIG. 18, and the cross section of the other part of the chucking device 40 is a cross section at a position corresponding to the cross section of the claw member 42c. The blade portion 422 of the claw member 42c includes a protrusion 429 that protrudes downward at the radially inner end. The protruding portion 429 is opposed to the annular portion 222 with a minute gap in a state where the disk 9 is not attached. The center case 41 is provided with two support portions 416 facing the two side portions 428 in the vertical direction.

  When the disc 9 is fixed to the chucking device 40, the disc 9 abuts against the tip of the central portion 427, so that the sliding contact surface 428 a of the side portion 428 comes into sliding contact with the upper end of the support portion 416, and the claw member 42 c. Rotates clockwise in FIG. When the disk 9 is placed on the placement surface 441, the claw member 42 c is pushed outward by the elastic member (not shown), and the inclined lower surface 4232 of the center portion 427 is It contacts the upper edge 911 of the center hole 91. In the blade portion 422, the protrusion portion 429 contacts the annular portion 222, thereby preventing the claw member 42 c from being pushed by the disk 9 and rotating counterclockwise.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

  For example, as shown in FIG. 23, in the claw member 42, the Nusumi part 7 may be formed to the outside in the radial direction from the contact position between the inclined lower surface 4232 on both sides of the groove part 4211 and the loaded disk 9. preferable. Note that the expression “outside in the radial direction” may be taken as a direction toward the tip of the claw member 42. Also in the claw member 42a shown in FIG. 16, as in FIG. 23, the urine portion 7a is formed to the outside in the radial direction from the contact position between the inclined lower surface 4232 on both sides of the groove portion 4211 and the loaded disc 9. Good.

  The shape of the Nusumi portion may be a shape other than that shown in the above embodiment, and the portion near the upper surface 4234, the tip portion 423, the inclined lower surface 4232 and / or the sliding contact surface 4212 is substantially thin. Anything can be used. Accordingly, sink marks on the upper surface 4234, the tip portion 423, the inclined lower surface 4232, and / or the sliding contact surface 4212 can be prevented.

  For example, a groove that vertically cuts the distal end portion 423, or a hole or groove that is recessed radially inward from the distal end portion 423 may be provided. Moreover, the Nusumi part may extend in a direction perpendicular to the radial direction. In any case, the occurrence of resin sink on the slidable contact surface 4212 is suppressed by at least a part of the Nusumi portion being located within the radial range where the slidable contact surface exists, and the chucking performance. Is stabilized.

  In the above embodiment, when the claw member 42 is injection molded, the parting line 63 may be provided at a position other than the position shown in FIG. For example, the upper part of the parting line 63 may be provided on the tip part 423 side of the claw part main body 421. The lower part of the parting line 63 may be positioned between the contact part 426 and the locking surface 4213.

  In the above embodiment, the crushed portion 7 of the claw member 42 shown in FIG. 7 may be provided inside the region 81 corresponding to the outer diameter of the elastic member 43 of the contact portion 426. In the claw member 42, the region on the claw member 42 can be effectively utilized when at least a part of the urine portion 7 is located in the region 81. The same applies to the claw members 42a to 42c shown in FIGS.

  Instead of the claw-side protrusion 424 that holds the elastic member 43, a recess into which the end of the elastic member 43 is inserted may be provided. In this case, the Nusumi part is preferably provided in the recess. Moreover, the contact part 426 and the Nusumi part do not need to overlap.

  In the claw member 42 of the above embodiment, the upper end 4231b and the upper surface 4234 of the front end surface 4231 are smoothly connected via the upper side chamfered shape surface 4235, but the upper side chamfered shape surface 4235 is omitted and the front end surface 4231 and The upper surface 4234 may be directly connected. Similarly, the lower side chamfered shape surface 4233 may be omitted, and the distal end surface 4231 and the inclined lower surface 4232 may be directly connected. The same applies to the claw members 42a to 42c shown in FIGS.

  In the claw member 42 shown in FIG. 6, an inclined lower surface from which the groove 4211 is omitted may be used as a sliding contact surface when the claw member 42 swings up and down. When the disc 9 is fixed to the chucking device 40, as shown in FIG. 24, the disc 9 comes into contact with the upper surface 4234 of the claw member 42, and the tip end portion 423 is slightly rotated clockwise. The claw member 42 moves radially inward while the inclined lower surface 4232 is in sliding contact with the upper end of the support portion 416. As shown in FIG. 25, when the disk 9 is placed on the placement surface 441, the inclined lower surface 4232 of the claw member 42 contacts the upper edge 911 of the center hole 91 of the disk 9.

  In the chucking device 40 of FIG. 3, the number of the claw members 42 may be more than three. Further, the annular mounting surface 441 does not have to be completely annular, and may be a surface that is discontinuous as long as it is approximately annular around the central axis J1.

  The chucking device 40 in the above embodiment may be employed in a device that drives various types of disks other than optical disks. Further, the disk drive device 50 only needs to read or write information to or from the disk 9, that is, read and / or write. The disk drive device 50 may be of a type other than the type in which the lid opens and closes. For example, the disk drive device 50 may be a so-called tray type in which the tray on which the disk is placed can be taken in and out of the housing.

  The chucking device according to the present invention can be used in various recording disk drive devices that read and / or write information on a disk.

DESCRIPTION OF SYMBOLS 1 Motor unit 7, 7a-7c Nusumi part 9 Disc 20 Rotor part 30 Stator part 40 Chucking device 41 Center case 42, 42a-42c Claw member 43 Elastic member 44 Mounting part 50 Disk drive device 51 Access part 52 Case 61 First mold 62 Second mold 63 Parting line 71 Inner surface 81 (of the Nussie part) 81 (Abutting part) region 89 Abutting position 91 Center hole 416 Support part 423 Tip part 426 Abutting part 4212, 428a Sliding contact Surface 4231 Front end surface 4231a Lower end (front end surface) 4231b Upper end (front end surface) 4232 Inclined lower surface 4234 Upper surface J1 Central axis

Claims (13)

A placement portion on which a disc having a center hole is placed, the center portion being placed around the center axis;
A plurality of claw members formed by resin injection molding and radially arranged around the central axis toward the radially outer side inside the placement portion;
A biasing portion that biases the plurality of claw members outward in the radial direction;
A center case that houses the plurality of claw members in a state in which the tip protrudes;
With
Each of the plurality of claw members rotates so that the tip moves up and down and moves in the radial direction when the disk is placed,
Each of the plurality of claw members is
A sliding contact surface that is in sliding contact with the guide portion of the center case when the disk is placed;
At least a part of the urine which is a hole or a notch located in a radial range where the sliding contact surface exists,
Chucking device having Each of the plurality of claw members is
A tip surface that is located above the sliding surface and approaches the central axis as it goes upward;
An upper surface located above the upper end of the tip surface and extending radially inward;
An inclined lower surface that is located on the lower side of the lower end of the distal end surface, approaches the central axis as it goes downward, and comes into contact with the disk placed on the mounting portion,
The chucking device according to claim 1, further comprising:   The chucking device according to claim 2, wherein at least a part of the inclined lower surface is located within a radial range in which the sliding contact surface exists.   The chucking device according to any one of claims 1 to 3, wherein the Nusumi portion is a cutout portion extending radially outward from an end portion on the radially inner side at an upper portion of each of the plurality of claw members.   The chucking device according to any one of claims 1 to 3, wherein the Nusumi part is a hole that opens radially inward.   The chucking device according to claim 4 or 5, wherein in each of the plurality of claw members, an abutting portion that abuts on the urging portion and the Nusumi portion are continuous. The urging portion is a coil spring;
The chucking device according to claim 6, wherein at least a part of the Nusumi part is located in a region corresponding to the outer diameter of the coil spring of the contact part.   The chucking device according to any one of claims 1 to 7, wherein the Nusumi portion and the sliding contact surface overlap each other in a plan view before the disc is placed.   An end portion on the radially outer side of the Nusumi portion is located radially outward in a plan view from a contact position between the sliding contact surface and the guide portion before the disc is placed. Item 8. A chucking device according to any one of Items 1 to 7.   The chucking device according to claim 8 or 9, wherein the sliding contact surface is directed upward as it is away from the central axis, and a lower portion of the inner surface of the Nusumi part is also directed upward as it is separated from the central axis.   Each of the plurality of claw members has a shape capable of separating two molds in a direction approximately corresponding to the radial direction at the time of injection molding, and the parting line is formed avoiding the sliding contact surface, The chucking device according to any one of claims 1 to 10. A rotor section;
A stator portion that rotatably supports the rotor portion;
The chucking device according to any one of claims 1 to 11, provided at an upper end of the rotor portion,
A motor unit comprising: The motor unit according to claim 12, wherein the disk is rotated,
An access unit for reading and / or writing information to and from the disk;
A housing for holding the motor unit and the access unit;
A disk drive device comprising:

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