JP2008077807A - Clamp mechanism and disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clamp mechanism accurately positioning a clamp for fixing a disk. <P>SOLUTION: A clamp mechanism 140, which fixes a disk 120 to a hub 115 of a spindle motor 110, is provided with a clamp 150 having an outer peripheral part 151 for pressing the disk 120 to the hub 115 side and a clamp through-hole 153 penetrating through the center, and a clamp screw 160 for fixing the clamp 150 by pressing the outer peripheral part 151 of the clamp 150 to the disk 120. The clamp screw 160 has a head part 161 for fastening an inner peripheral part of the clamp 150, a screw part 163 being screwed into the hub 115, and a column shape positioning part 162 which is smoothly formed between the head part 161 and the screw part 163 and has an outer diameter size slightly smaller than the inner diameter size of the clamp through-hole 153. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a clamp mechanism, and more particularly to a clamp mechanism for fixing a disk to a spindle motor and a disk apparatus using the same.

  In the automatic assembly process of hard disk drives, it is important to simplify the assembly work of the hard disk drives as much as possible. A conventional hard disk drive includes a spindle motor that rotates a disk that is an information recording medium, an actuator that rotates a head that records and / or reproduces data on the disk, and a clamp mechanism that fixes the disk to the hub of the spindle motor. Composed. The clamp mechanism includes a clamp that presses the inner peripheral surface of the disk from the upper side of the disk, and a clamp screw that fixes the clamp.

  In such a hard disk drive, first, the disk is placed on the hub of the spindle motor. Next, a clamp is arranged from above the disk, a clamp screw is inserted through a through hole formed at the center of the clamp, and is screwed into the central axis portion of the spindle motor, and the inner periphery of the disk is clamped by the outer periphery of the clamp. Press. In this way, the disk is fixed by fixing the clamp and the spindle motor.

  In assembling such a hard disk drive, positioning of the clamp is extremely important. If the disc fixing position of the clamp is deviated, the disc fixed by the clamp is tilted, causing a problem in reading and writing of the disc. Therefore, in a conventional hard disk drive, as shown in FIG. 5, for example, a protrusion 21 is provided on the upper surface of the hub 20 of the spindle motor, and the inner peripheral surface 31a of the clamp 30 is brought into contact with the outer peripheral surface 21a of the protrusion 21. In this state, a clamp mechanism configured by fixing the clamp 30 with the clamp screw 40 is provided (for example, Patent Document 1). By providing the protrusion 21 on the hub 20 of the spindle motor, even if the clamp 30 moves in the radial direction of the disk 10, the inner peripheral surface 31 a of the hub 20 contacts the outer peripheral surface 21 a of the protrusion 21. Therefore, the clamp 30 can be easily positioned.

JP 2004-234793 A

  However, the above configuration is not problematic when the disk size is large, but for example, a small hard disk drive of 2.5 inches or less cannot secure a sufficient height. For this reason, a protrusion cannot be provided on the upper surface of the hub, and positioning of the clamp is difficult. On the other hand, when the protrusion is provided, the area for installing the motor bearing is narrowed in order to secure the area for providing the protrusion. For this reason, in a hard disk drive having a small disk size, the length of the motor bearing necessary for maintaining the rigidity of the motor cannot be ensured.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved clamping mechanism capable of accurately positioning a clamp for fixing a disk, and It is to provide a disk device.

  In order to solve the above problems, according to one aspect of the present invention, a clamp mechanism for fixing a disk to a hub of a spindle motor is provided. The clamp mechanism according to the present invention includes a clamp having an outer peripheral portion that presses the disc on the hub side, and a clamp through hole that penetrates the center, a clamp screw that presses the outer peripheral portion of the clamp against the disc and fixes the clamp, Is provided. Here, the clamp screw is formed smoothly between the head that locks the inner periphery of the clamp, the screw that is screwed into the hub, and the head and the screw. And a cylindrical positioning portion having a slightly smaller outer diameter.

  According to the present invention, the substantially cylindrical positioning portion formed smoothly on the clamp screw is formed. The positioning part of the clamp screw is formed at a position facing the inner peripheral surface of the clamp through hole when the clamp screw is screwed into the hub. With such a configuration, even if the clamp moves in the radial direction of the disk, the inner peripheral surface of the clamp through hole comes into contact with the positioning portion, and the movement of the clamp can be restricted. This makes it possible to accurately position the clamp without providing a protrusion on the hub as in the prior art, and eliminate the space required to provide the protrusion, thus reducing the overall height of the device. can do.

  Here, the edge of the clamp through hole on the head side of the clamp screw may be removed. The connection portion between the head of the clamp screw and the positioning portion has, for example, an inverted R shape. By removing the edge of the clamp through-hole, the reverse R shape of the clamp screw connecting portion can be released, so that the overall height of the apparatus including such a clamp mechanism can be reduced.

  Furthermore, the engaging part which engages with the to-be-engaged part formed in the surface facing the clamp of a hub can also be formed in the surface facing a hub of a clamp. When the engaging part of the clamp and the engaged part of the hub are engaged, the fixing position of the clamp can be easily determined at the time of assembly. Even if the clamp receives an impact that moves in the radial direction of the disk, the clamp engaging portion and the engaged portion of the hub come into contact with each other, so that the movement of the clamp can be restricted. Here, the engaging part of a clamp can be formed in the shape which protruded in the hub side at the edge of the hub side of a clamp through-hole, for example.

  Here, the inner diameter of the clamp through hole is formed slightly larger than the outer diameter of the positioning portion of the clamp screw. The gap formed between the outer peripheral surface of the positioning portion of the clamp screw and the inner peripheral surface of the clamp through hole is set to a size that does not affect the positioning of the clamp even if the clamp moves. For example, the inner diameter of the clamp through hole can be determined so that a gap of about 10 to 20 μm is formed between the outer peripheral surface of the positioning portion of the clamp screw and the inner peripheral surface of the clamp through hole.

  Such a clamping mechanism can be used in a disk device including a disk, a spindle motor that rotates the disk, and an actuator that rotates and moves a head that records and / or reproduces data on the disk. In particular, the disk device of the present invention is suitable for use in a small disk device because the overall height of the disk device can be lowered by using the clamp mechanism having the above-described configuration.

  As described above, according to the present invention, it is possible to provide a clamp mechanism and a disk device capable of accurately positioning a clamp for fixing a disk.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  First, a schematic configuration of a hard disk drive 100 according to an embodiment of the present invention will be described based on FIG. 1 and FIG. FIG. 1 is a plan view showing a schematic configuration of the hard disk drive 100 according to the present embodiment. FIG. 2 is a partial cross-sectional view taken along the line AA in FIG. 1 and shows a state before the clamp 150 is fixed by the clamp screw 160.

  As shown in FIG. 1, the hard disk drive 100 according to the present embodiment records and / or records data on a disk 120 and a spindle motor 110 that rotates a disk 120 that is a data storage medium in a substantially rectangular housing 105. The actuator 130 includes a reproducing head 135 and a clamp mechanism 140 for fixing the disk.

  The spindle motor 110 is a motor that rotates the disk 120, and the spindle shaft is rotated by the action of a magnetic circuit and a magnet. As shown in FIG. 2, the spindle motor 110 is provided with a hub 115 so as to cover the upper side of the spindle motor 110. The hub 115 is formed in a substantially disk shape when viewed from the z direction, and the height (z direction) of the outer peripheral portion 115d is formed lower than the inner peripheral side. Further, a screw hole 115g into which a clamp screw 160 described later is screwed is formed at the center of the spindle motor 110.

  The hub 115 supports the inner peripheral portion of the disk 120 on the upper surface 115e of the outer peripheral portion 115d. At this time, the disk 120 is provided such that the inner peripheral surface of the disk 120 contacts the outer peripheral surface 115 f of the hub 115. Further, an engaged portion 115a that engages with an engaging portion 153c of a clamp 150, which will be described later, is formed on the upper surface (the surface on the z positive direction side) of the hub 115. In the present embodiment, the engaged portion 115 a of the hub 115 is formed as a step formed by removing the edge on the inner peripheral side of the hub 115.

  As shown in FIG. 1, the actuator 130 includes a head 135 for recording and / or reproducing data on the disk 120, a head suspension assembly 137 having one end attached to a rotating shaft 133 and the other end having a head 135. It is comprised. By rotating the head suspension assembly 137 and moving the head 135 to a predetermined position on the disk 120, data can be recorded and / or reproduced on the disk 120. The actuator 130 can be driven by, for example, a voice coil motor (VCM; Voice Coil Motor, not shown).

  As shown in FIG. 2, the clamp mechanism 140 includes a clamp 150 for fixing the disk 120 and a clamp screw 160 for fixing the clamp 150 to the hub 115. The clamp 150 is made of a spring member formed in a substantially disc shape, and is formed with an outer peripheral portion 151 that presses the disk 120 toward the hub 115 (the negative z direction side), and a clamp through hole 153 that passes through the center of the clamp 150. ing.

  A part of the outer peripheral portion 151 of the clamp 150 is formed in a shape protruding to the hub 115 side (z negative direction side). On the other hand, a step is formed on the inner peripheral side of the clamp 150 according to the present embodiment so that the height decreases toward the center. A lower surface of a head 161 of a clamp screw 160, which will be described later, comes into contact with the upper surface 152 that is lowered by one step.

  The clamp through hole 153 is formed to be concentric with the rotation shaft of the spindle motor 110 when the clamp 150 is placed on the hub 115. The diameter of the clamp through hole 153 is slightly larger than the diameter of the positioning portion 162 of the clamp screw 160. The gap formed between the smooth surface 162b (see FIG. 4) of the positioning portion 162 of the clamp screw 160 and the inner peripheral surface 153b (see FIG. 4) of the clamp through hole 153 is caused by the clamp 150 being moved by an impact, for example. Is set to a size that does not affect the positioning of the clamp 150. For example, the clamp through hole 153 is formed so that a slight gap of about 10 to 20 μm is formed between the inner periphery of the clamp through hole 153 and the outer periphery of the positioning portion 162 of the clamp screw 160.

  Further, the edge of the clamp through-hole 153 on the head 161 side (z positive direction side) of the clamp screw 160 is removed, and a concave portion 153a that is recessed in the z negative direction side is formed. The concave portion 153a is formed in a size that allows the connection portion 162a of the clamp screw 160 to enter and allow the inverted R shape of the connection portion 162a to escape. Furthermore, an engaging portion 153 c that engages with an engaged portion 115 a formed on the hub 115 is formed on the surface of the clamp 150 on the hub 115 side. In the present embodiment, the engaging portion 153c of the clamp 150 is formed by protruding the lower surface side (z negative direction side) edge of the clamp through hole 153 in the z negative direction.

  The clamp screw 160 is a fixing member for fixing the clamp 150 to the hub 115. The clamp screw 160 includes a head portion 161 that locks the upper surface of the clamp 150, a screw portion 163 that is screwed into the rotation center portion of the hub 115, and a positioning portion 162 that is provided between the head portion 161 and the screw portion 163. Consists of.

  The head 161 of the clamp screw 160 is formed in a substantially disc shape, for example, and the diameter of the head 161 is larger than the diameter of the clamp through hole 153. For this reason, the lower surface 161a of the head 161 is in contact with the upper surface 152 of the clamp 150 and presses the inner periphery of the clamp 150 toward the hub 115 in the assembled state of the hard disk drive 100. The movement in the (z direction) can be restricted.

  The threaded portion 163 of the clamp screw 160 is formed with a thread so as to correspond to the threaded groove formed in the threaded hole 115g at the center of rotation of the hub 115. By screwing the screw part 163 into the screw hole 115 g of the hub 115, the clamp 150 can be pressed and fixed by the head part 161.

  The clamp screw 160 according to the present embodiment is characterized in that a positioning portion 162 is formed between a head portion 161 and a screw portion 163. The positioning portion 162 is provided for positioning the clamp 150 and is formed in a substantially cylindrical shape with a smooth surface. For this reason, the positioning part 162 is formed at a position facing the inner peripheral surface 153b of the clamp through hole 153 in a state where the hard disk drive 100 is assembled.

  In such a hard disk drive 100, the disk 120 fixed by the clamp mechanism 140 is rotated by, for example, the arrow D direction in FIG. Then, in order to record and / or reproduce data, the actuator 130 is driven to move the head 135 to a predetermined position on the disk 120.

  The schematic configuration of the hard disk drive 100 according to the present embodiment has been described above. The hard disk drive 100 according to the present embodiment is a clamp mechanism that can position the clamp without providing a protrusion for positioning the clamp on the upper surface of the spindle motor hub as in the conventional hard disk drive shown in FIG. It is characterized by providing.

  Then, based on FIGS. 2-4, the structure of the clamp mechanism 140 is demonstrated in detail along the flow of the assembly process of the clamp mechanism 140 concerning this embodiment. 3 is a partial cross-sectional view taken along the line AA of FIG. 1 and shows a state in which the clamp 150 is fixed by the clamp screw 160. FIG. FIG. 4 is a partially enlarged view of FIG. 3 showing the clamp mechanism 140 according to the present embodiment.

  In the process of fixing the disk 120 by the clamp mechanism 140 in the hard disk drive 100 according to the present embodiment, first, the disk 120 is placed on the outer peripheral portion 115d of the hub 115 of the spindle motor 110 as shown in FIG. The disc 120 is supported on the inner peripheral side by the upper surface 115e of the outer peripheral portion 115d of the hub 115.

  Next, the clamp 150 is placed from above the disk 120 placed on the hub 115. At this time, the outer peripheral portion 151 protruding to the hub 115 side of the clamp 150 is in contact with the upper surface on the inner peripheral side of the disk 120. At this time, the outer peripheral portion 151 of the clamp 150 is positioned so as to face the upper surface 115 d of the hub 115. Further, the engaging portion 153 c formed on the surface of the clamp 150 on the hub 115 side engages with the engaged portion 115 a formed on the upper surface of the hub 115. In this way, when the clamp 150 is placed on the hub 115, the clamp 150 engages with the hub 115, so that the movement of the clamp 150 in the radial direction (x direction in FIG. 2) is restricted. The fixing position of the clamp 150 can be easily determined.

  After the clamp 150 is placed on the hub 115, the clamp screw 160 is screwed into the hub 115 to fix the clamp 150. The clamp screw 160 is inserted into the screw hole 115 g of the hub 115 through the clamp through hole 153 of the clamp 150. Here, the connecting portion 162a between the head 161 of the clamp screw 160 and the positioning portion 162 has an inverted R shape, and is formed by removing the edge of the clamp through hole 153 on the head 161 side of the clamp screw 160. The recessed portion 153a is fitted. With this configuration, the clamp screw 160 is inserted so as to be introduced into the screw hole 115g of the hub 115, so that the clamp screw 160 can be easily attached.

  When the clamp screw 160 is screwed into the screw hole 115g of the hub 115 and fixed, the lower surface of the head 161 of the clamp screw 160 engages the upper surface 152 on the inner peripheral side of the clamp 150, as shown in FIG. . Thereby, the movement of the clamp 150 in the vertical direction (z direction) can be restricted, and the tilt of the disk 120 can be prevented.

  At this time, the inner peripheral surface 153 b of the clamp through-hole 153 faces the smooth surface 162 b of the positioning portion 162 of the clamp screw 160. Therefore, for example, in FIG. 4, even if the clamp 150 moves to the center side (x negative direction side), the inner peripheral surface 153b of the clamp through-hole 153 and the smooth surface 162b of the positioning portion 162 of the clamp screw 160 come into contact. As a result, the movement of the clamp 150 is restricted. At this time, since the movement of the clamp 150 is a slight distance of about 10 to 20 μm, it does not have a great influence as the disk 120 tilts.

  On the other hand, in FIG. 4, when the clamp 150 moves to the outer peripheral side (x positive direction side), the engaging portion of the clamp 150 and the engaged portion of the hub 115 are engaged. can do. In this embodiment, when the engaging portion 153c of the clamp 150 contacts the stepped portion of the engaged portion 115a of the hub 115, the movement of the clamp 150 is restricted. Thus, by restricting the movement of the clamp 150, the tilt of the disk 120 can be prevented.

  Further, the connecting portion 162 a having an inverted R shape between the head 161 of the clamp screw 160 and the positioning portion 162 enters the recess 153 a formed by removing the edge of the clamp through hole 153 on the clamp screw 160 side. As a result, the height of the hard disk drive 100 as a whole can be lowered by the height of the connecting portion 162a.

  As described above, the clamp mechanism 140 according to the present embodiment is provided with the positioning portion 162 for positioning the clamp 150 on the clamp screw 160, so that it is possible to obtain accuracy without forming a protrusion on the hub 115 as in the conventional case. The clamp 150 can be well positioned. Furthermore, since the space required to form the protrusions can be omitted, the overall height of the device can be reduced, and the length of the motor bearing required to maintain the rigidity of the motor can be secured. It is. Further, by providing the engaging portion 153c on the clamp 150 and the engaged portion 115a on the hub 115, the fixing position of the clamp 150 can be easily determined, and the displacement of the clamp 150 can be prevented.

  Furthermore, by providing the concave portion 153a at the edge on the upper surface side of the clamp through hole 153, the reverse R shape of the connection portion 162a of the clamp screw 160 can be released, and the height of the entire apparatus can be reduced. Further, since the concave portion 153a is formed, the clamp screw 160 is inserted into the clamp through hole 153 so as to be introduced, so that the assembly process of the hard disk drive 100 can be easily performed.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above embodiment, the engaged portion 115a of the hub 115 is recessed and the engaging portion 153c of the clamp 150 is formed to protrude, but the present invention is not limited to such an example. For example, the engaged portion 115a of the hub 115 may protrude toward the clamp 150, and the engaging portion 153c of the clamp 150 may be recessed. Moreover, in the said embodiment, although the to-be-engaged part 115a of the hub 115 and the engaging part 153c of the clamp 150 were formed in the edge of an inner peripheral side, this invention is not limited to this example, and an outer peripheral side rather than an edge You may form in.

1 is a plan view showing a schematic configuration of a hard disk drive according to an embodiment of the present invention. It is a fragmentary sectional view in the AA cutting line of FIG. 1, and shows the state before a clamp is fixed with a clamp screw. It is a fragmentary sectional view in the AA cutting line of FIG. 1, and shows the state by which the clamp was fixed by the clamp screw. It is the elements on larger scale of FIG. 3 which shows the clamp mechanism concerning this embodiment. It is a fragmentary sectional view showing the conventional clamp mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Hard disk drive 110 Spindle motor 115 Hub 115a Engagement part 120 Disk 130 Actuator 140 Clamp mechanism 150 Clamp 153a Recess 153c Engagement part 160 Clamp screw 161 Head 162 Positioning part 162a Connection part 162b Smooth surface 163 Screw part

Claims (6)

A clamp mechanism for fixing a disk to a hub of a spindle motor,
A clamp including an outer peripheral portion that presses the disk on the hub side, and a clamp through-hole penetrating the center;
A clamp screw for fixing the clamp by pressing the outer periphery of the clamp against the disc;
With
The clamp screw is
A head for locking the inner periphery of the clamp;
A screw portion screwed into the hub;
A cylindrical positioning portion that is formed smoothly between the head portion and the screw portion and has an outer diameter slightly smaller than the inner diameter of the clamp through-hole,
A clamping mechanism characterized by comprising:   The clamp mechanism according to claim 1, wherein an edge of the clamp through hole on a head side of the clamp screw is removed.   The engagement portion that engages with the engaged portion formed on the surface of the hub that faces the clamp is formed on the surface of the clamp that faces the hub. 2. The clamping mechanism according to 2.   The clamp mechanism according to claim 3, wherein the engaging portion of the clamp is formed at an edge of the clamp through hole on the hub side.   The gap of 10-20 micrometers is formed between the outer peripheral surface of the positioning part of the said clamp screw, and the inner peripheral surface of the said clamp through-hole, The Claim 1 characterized by the above-mentioned. Clamp mechanism. A disc,
A spindle motor for rotating the disk;
An actuator for rotating and moving a head for recording and / or reproducing data on the disk;
The clamp mechanism according to any one of claims 1 to 5, wherein the disk is fixed to a hub of the spindle motor.
A disk device comprising:

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