JP5063276B2 - Clamp for disk rotation drive device and method for manufacturing clamp - Google Patents

Description

  The present invention relates to a clamp of a disk rotation drive device such as a hard disk drive (HDD “Hard Disk Drive”) used in an information processing apparatus such as a computer, and a clamp manufacturing method.

  Conventionally, there is one disclosed in Patent Document 1 as a clamp of a disk rotation driving device.

  This clamp is attached by a balance ring (wire balancer), which is attached to adjust the rotational balance, disposed in the annular groove and locked in the radial direction or the rotational direction. This balance ring can suppress rotational runout during motor rotation.

  However, since the balance ring has a structure that is locked in the radial direction or the rotation direction, the rotation in the rotation axis direction is insufficient, and the balance ring may fall out in the rotation axis direction when an impact is input.

  On the other hand, the structure of the reference example shown in FIGS. 4 is a plan view of the clamp, FIG. 5 is a plan view of the C-ring, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG.

  As shown in FIGS. 4 to 6, the clamp 101 includes a locking wall 103 on the outer peripheral portion, and the C-ring 105 that is the C-type balance ring shown in FIG. It is fitted to become. The C-ring 105 is elastically locked to the locking wall 103 with an elastic force in the opening direction, and the overhang portion 107 prevents the C-ring 105 from coming off in the rotation axis direction with respect to the clamp 101.

  However, when the overhang portion 107 is simply formed, the thickness of the overhang portion 107 increases, and there is a problem that the weight increases and the balance error of the weight tends to be caused in the circumferential direction.

  Such a problem is caused when the overhang portion 107 is formed by either press molding or cutting. In particular, in the press molding, the shape of the overhang portion (convex portion) is caused by a large bending resistance. Due to the variation, it is easy to cause a weight balance error in the circumferential direction.

WO2003 / 001522

  The problem to be solved is that when the overhang portion is simply formed, the thickness of the overhang portion increases, the weight increases accordingly, and a balance error of the weight tends to be caused in the circumferential direction.

  In press molding, the bending resistance is large, and variation in the shape of the overhang portion (convex portion) tends to cause a weight balance error in the circumferential direction.

In the present invention, when the overhang portion is formed by press working, the central portion is fixed to a rotary body that can be rotationally driven in order to reduce bending resistance in the bending process and make it difficult to cause a balance error in weight in the circumferential direction. In addition, the outer peripheral portion is provided with a contact portion in a circular shape, and the outer peripheral portion has a lock ring of a balance ring for adjusting the rotation balance on the rotating body side, and the inner peripheral side of the lock wall. Further, it has an overhang portion that protrudes radially inward to prevent the balance ring from being locked in the rotation axis direction, and abuts the contact portion on a disk that is mounted on the rotating body and capable of recording information. The disk is fixedly supported on the rotating body by applying a pressing force in the direction of the rotation axis, and the balance ring is disposed on the inner peripheral side of the locking wall, and the overhang portion causes the rotation axis direction to stop engaging escape to A clamping of the disk rotation driving apparatus, meat movement in the thickness direction by the press forming of the recess and the portion to be in the thickness direction side of the bent portion to the engagement Tomekabe prior to molding of the engaging wall The feature of the clamp of the disk rotation driving device is that the portion to be the overhang portion is formed by protruding, and then the portion to be the overhang portion is formed as the overhang portion by bending the locking wall. To do.

In addition, the central part is fixed to the rotatable rotating body and the outer peripheral part is provided with a contact part in a circular shape, and the outer peripheral part is provided with a locking wall of a balance ring for adjusting the rotational balance on the rotating body side. And has an overhang portion on the inner peripheral side of the locking wall that protrudes radially inward to prevent the balance ring from coming off and locked in the direction of the rotation axis,
The disk is fixedly supported by the rotating body by applying the pressing force in the direction of the rotation axis by bringing the abutting portion into contact with the disk mounted on the rotating body and capable of recording information. A clamp manufacturing method wherein the balance ring is disposed on the inner peripheral side of the stop wall, and the locking wall of the clamp of the disk rotation driving device that locks the locking ring in the rotational axis direction by the overhang portion is raised by bending with a press. In addition, before the locking wall is bent, the overhang portion is formed by moving the portion in the plate thickness direction by pressing the portion to be the concave portion on the side surface in the plate thickness direction of the portion to be the locking wall. A characteristic of the clamp manufacturing method is that a portion to be the overhang portion is formed as the overhang portion by projecting the portion to be projected and then bending the locking wall .

The present invention provides a locking ring for a balance ring that has a central portion fixed to a rotary body that can be driven to rotate and a circumferentially provided contact portion on the outer peripheral portion, and that adjusts the rotational balance on the rotary body side on the outer peripheral portion. And has an overhang portion on the inner peripheral side of the locking wall that protrudes radially inward to prevent the balance ring from coming off and locked in the rotation axis direction, and is attached to the rotating body. By abutting the abutting portion on a disc capable of recording information and applying a pressing force in the direction of the rotational axis, the disc is fixedly supported on the rotating body, and the inner peripheral side of the locking wall The disk is a clamp of a disk rotation drive device in which the balance ring is arranged and is prevented from coming off in the direction of the rotation axis by the overhang portion, and the plate of the portion to be the locking wall before bending the locking wall The part which should become the concave part in the thickness direction side The overhang portion and the portion to be meat movement in the thickness direction by the press forming protrudes molding, and then forming a bent portion to the said overhang portion by molding of said engaging wall as the overhang portion.

  For this reason, an increase in weight can be suppressed while having an overhang portion. Moreover, the balance error of the weight in the circumferential direction can be suppressed by suppressing the increase in weight, suppressing the bending resistance, or the like.

Further, in the clamp manufacturing method of the present invention, the protrusion of the overhang portion is caused by the movement of the clamp material due to the press molding of the portion to be the recess before the locking wall is bent .

For this reason, for example, when forming a locking wall having a height lower than the plate thickness of three times or less of the plate thickness of the clamp material by press working, the bending process is to press the portion to be the overhang portion By carrying out before, a desired shape can be obtained , variation in the shape of the overhang part (convex part) can be suppressed, and a weight balance error in the circumferential direction can hardly be caused.

  While forming the overhang part, the concave part corresponding to the overhang part is formed in a circular shape for the purpose of suppressing the weight increase due to the increase in thickness and making the balance error of the weight in the circumferential direction difficult. And realized.

  In addition, when the overhang portion is formed by press working, the protrusion of the overhang portion is formed by pressing the concave portion for the purpose of reducing bending resistance in the bending process and making it difficult to cause a weight balance error in the circumferential direction. It was realized by causing the meat movement of the clamp material.

[Clamp]
FIG. 1 is a cross-sectional view of a clamp according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged cross-sectional view of the main part.

  The clamp 1 of FIG. 1 is attached to a disk rotation drive device (not shown) such as a 2.5-inch server HDD. The disk rotation driving device rotates and drives a magnetic disk (described later) capable of recording / reproducing information.

  The disk rotation driving device fixedly supports a magnetic disk on a hub (not shown) which is a rotating body that can be rotated by a pressing force in the direction of the rotation axis by the clamp 1.

  The clamp 1 is, for example, formed of a springy stainless steel in a rotating body shape. The hub 1 is a rotating body (not shown) provided with a contact portion 5 on the outer peripheral portion 3 in a circular shape and whose central portion can be driven to rotate. ) Is fastened and fixed to a fitting shaft portion (not shown) by screws (not shown). The abutting portion 5 of the clamp 1 abuts on a magnetic disk 7, which is a disk capable of recording information, and applies a pressing force in the direction of the rotation axis to support the magnetic disk 7 fixedly on the hub. Yes.

  As shown in FIGS. 1 and 2, the clamp 1 is generally formed in a hat cross-sectional shape, and a central portion 9 is formed to be recessed with respect to the outer peripheral portion 3, and a through-hole through which a screw penetrates the central portion 9. 11 is provided.

  On the outer peripheral portion 3 of the clamp 1, the abutting portion 5 is formed in a circular shape with a curved cross section so as to be oriented in the axial direction.

  A locking wall 15 is formed on the outer peripheral portion 3 so as to circulate around the outer peripheral side of the contact portion 5. The locking wall 15 supports the C ring 17 that is a balance ring for adjusting the rotational balance by elastically contacting the C ring 17 in the radial direction. The diameter D of the C-ring 17 is φ0.7 in this embodiment, although it depends on the size of the HDD.

  The height h from the abutment portion 5 that is the rising dimension of the locking wall 15 is not more than three times the plate thickness of the clamp material (h / t ≦ 3), and the C ring 17 can be locked. More than the dimension. In this embodiment, h = 1.5 mm with respect to the plate thickness t = 0.6 mm of the clamp material. The numerical value less than 3 times the plate thickness of the clamp material is defined by the difficulty in press molding and the height (thickness) dimension constraint in 2.5 inch small HDD.

  The inner peripheral surface 19 of the locking wall 15 is a surface along the rotation axis. An overhang portion 21 is provided on the inner peripheral side of the locking wall 15 to prevent the C-ring 17 from coming off in the direction of the rotation axis. The overhang portion 21 is formed so as to protrude radially inward with respect to the inner peripheral surface 19.

  The overhang portion 21 is set so as to protrude within a range of 0.1 to 0.3 mm with respect to the inner peripheral surface 19 of the locking wall 15 with which the C-ring 17 abuts. = 0.15 mm. The overhang portion 21 has an inclined inner peripheral surface 23 that is inclined with respect to the rotation axis direction. An angle θ formed by the inclined inner peripheral surface 23 with respect to the inner peripheral surface 19 of the locking wall 15 is set in a range of 15 ° to 45 ° with respect to the rotation axis direction. In this embodiment, θ = 25 °. Is set.

  On the outer peripheral side of the locking wall 15, a concave portion 25 corresponding to the overhang portion 21 is formed in a circular shape. In this embodiment, the concave portion 25 has a cross-sectional shape having a size corresponding to the overhang portion 21. That is, the concave portion 25 is a V-shaped V-notch having an obtuse angled cross section due to the concave inclined surfaces 27 and 29, and the concave inclined surface 27 is parallel or nearly parallel to the inclined inner peripheral surface 23 of the overhang portion 21. Is formed. The deepest portion of the recess 25 corresponds to the intermediate portion of the overhang portion 21 in the radial direction of the clamp 1. The depth d of the deepest portion of the recess 25 is substantially the same as the protruding amount p of the overhang portion 21.

  In this embodiment, the protrusion of the overhang portion 21 is caused by the movement of the clamp material due to the press forming of the recess 25.

  In the clamp 1 having such a configuration, the C ring 17 can be elastically locked to the inner peripheral surface 19 of the locking wall 15. When an impact is input or the like, the overhang portion 21 can prevent the C-ring 17 from coming off from the clamp 1 in the rotation axis direction.

[Center run-out regulation during motor rotation by C-ring]
HDDs generally used as main storage devices used in computers differ in characteristics and quality required depending on the environment in which the computers are used.

  The HDD in which the clamp 1 of the embodiment of the present invention is used is mainly used as a company server, and has a higher level of access speed, reliability, etc. than those used for other uses such as personal use computers and portable devices. Required.

  In particular, the access speed largely depends on the rotational speed of a magnetic disk as a storage medium, and HDDs used for applications other than servers are overwhelmingly those with 7,200 rpm or less, but are used for server applications. The HDD to be rotated has a high rotation speed of 10,000 to 15,000 rpm, so that even when there are multiple accesses, the HDD can react at high speed.

  However, when the motor rotates at a high speed, the influence on the access accuracy due to the center shake at the time of rotation of the motor becomes large. Generally, in a server HDD, it is necessary to regulate the motor rotation shaft runout. A regulation mechanism is also provided.

  In the server HDD in which the clamp 1 of this embodiment is used, this center deflection can be restricted by the C ring 17 called a balance ring.

  That is, when assembling, first, the center runout is measured without attaching the C ring 17.

  The opening side of the C ring 17 is arranged at an appropriate position so that the center deflection is corrected, and the C ring 17 is set on the clamp 1.

  Measure the center run again to confirm that there is no problem.

[Clamp manufacturing method]
In the clamp manufacturing method of the clamp according to the embodiment of the present invention, in the first bending process, the primary bending of the portion to be the outer peripheral portion 3 of the clamp material 39 is performed.

  Next, in the second bending step, the portion to be the concave portion 25 is molded and the portion to be the overhang portion 21 is projecting. The portion to be the overhang portion 21 is formed by the movement of the clamp material by press molding of the portion to be the concave portion 25 using press molding.

  Thereafter, in the third bending step, the overhang portion 21 is formed by bending the locking wall 15.

  Conventionally, control of rotational runout by the balance ring is performed in a 3.5-inch HDD, and the clamp is formed by cutting using aluminum as a clamp material.

  By the way, until several years ago, there was no question about miniaturization of server HDDs, so most of them used 3.5-inch HDDs.

  However, in recent years, servers have been required to save space, reduce power consumption, and be quiet, and a smaller 2.5-inch HDD that is advantageous for achieving these characteristics is used for servers. Has come to be seen a lot.

  However, even with a 2.5-inch HDD, the center deflection during rotation is required, and a C-ring retaining structure is required for the clamp.

  However, a 2.5-inch HDD is only about 1/2 to 1/3 the thickness of a 3.5-inch HDD, and it is necessary to suppress the total thickness (height) of the clamp. It is necessary to make changes to the clamp used in the HDD. This change is shown below.

  Material change: Clamp material is changed from aluminum to stainless steel. This is because it is necessary to reduce the thickness of the material while maintaining the clamping force, so that the material can withstand high stress.

  Change of processing method: Cutting is changed to press processing. In general, machining increases the cost, so press processing is performed to reduce the cost or suppress the increase in cost.

  Suppression of the total height of the clamp: It is necessary to suppress the dimension h according to the thickness of the 2.5 inch HDD.

The manufacturing method of the embodiment of the present invention can produce the clamp 1 used for the 2.5-inch HDD in a form satisfying all these requirements.
[Effect of Example]
In the embodiment of the present invention, the central portion is fastened and fixed to a hub that can be driven by rotation, and the outer peripheral portion 3 is provided with a contact portion 5 in a circular shape. The magnetic disk is attached to the hub and can record information. In the clamp 1 of the disk rotation driving device that fixedly supports the magnetic disk on the hub by applying a pressing force in the direction of the rotation axis by bringing the contact part 5 into contact, the outer peripheral part 3 is balanced in rotation. A locking wall 15 of the C-ring 17 to be adjusted is provided in a circular shape, and an overhang portion 21 that can be locked to prevent the C-ring 17 from coming off in the direction of the rotation axis is provided radially inward on the inner peripheral side of the locking wall 15. A concave portion 25 corresponding to the position of the overhang portion 21 is formed in a circular shape on the outer peripheral side of the locking wall 15.

  For this reason, the overhang portion 21 and the recess 25 are formed relatively while having the overhang portion 21 to absorb the shape error, and the weight balance error in the circumferential direction can be suppressed.

  Here, the processing method of the present invention is not limited, but in particular, when the overhang portion 21 is simply formed by press molding, the bending resistance in press molding is large, and due to variations in the shape of the overhang portion (convex portion). This tends to cause a weight balance error in the circumferential direction.

  On the other hand, when the overhang portion 21 is press-molded together with the concave portion 25, the overhang portion 21 (convex portion) shape is formed while the overhang portion 21 is formed by press molding by suppressing the bending resistance of the press. Variations can be suppressed and a balance error in weight in the circumferential direction can be suppressed.

  The concave portion 25 has a cross-sectional shape having a size corresponding to the protruding amount of the overhang portion 21.

  For this reason, the shape error of the locking wall 15 can be reliably suppressed.

  The overhang portion 21 protrudes in the radial direction within a range of 0.1 to 0.3 mm, for example, p = 0.15 mm, with respect to the inner peripheral surface 19 of the locking wall 15 with which the C ring 17 abuts.

  For this reason, it is possible to reliably prevent the C-ring 17 from coming off.

  The overhang portion 21 has an inclined inner peripheral surface 23 that is set to be inclined at an angle of θ = 25 °, for example, in a range of 15 ° to 45 ° with respect to the rotation axis direction.

  For this reason, it is possible to reliably prevent the C-ring 17 from coming off.

  The height h of the locking wall 15 from the abutment portion 5 is not more than three times the plate thickness t of the clamp material and is not less than the dimension enabling the C-ring 17 to be locked.

  For this reason, it is possible to cope with a thin 2.5-inch HDD while enabling press molding, and the C-ring 17 can be reliably locked.

  The protrusion of the overhang portion 21 results from the movement of the clamp material due to the press forming of the concave portion 25.

  For this reason, when performing the molding of the portion to be the concave portion 25 and the projecting molding of the portion to be the overhang portion 21 in the second bending step, the portion to be the overhang portion 21 is the concave portion 25 using press molding. It can be formed by moving the clamp material by pressing the portion to be formed.

  After forming the portion to be the recess 25 and projecting the portion to be the overhang portion 21, the overhang portion 21 is formed by bending the locking wall 15.

  For this reason, even under conditions with considerable restrictions on the clamp height, such as 2.5-inch server HDDs, overhangs are made using stainless steel as the clamp material to reduce the material thickness and maintain the clamping force. It is possible to perform press working including the portion 21, and it is possible to easily process the overhang portion even with a stainless steel clamp material, and it is possible to reduce cost or suppress increase in cost.

[Modification]
FIG. 3 is a cross-sectional view of the main part showing the cross-sectional shape of the recess according to a modification of the embodiment of the present invention.

  In the above embodiment, the recess 25 is an obtuse V-shaped notch having a V-shaped cross section, whereas the recess 25A shown in FIG. 3B, a concave portion 25C as a right-angle V-notch in FIG. 3C, a concave portion 25D having a bottom of the right-angle V-notch in FIG. 3D as an arc, and a right-angled portion in FIG. A recess 25E having a plurality of V notches may also be used.

In the modification of FIG. 3 (d), the bottom of the V-notch having an obtuse angle and an acute angle can be a recess having an arc, and in the modification of FIG. 3 (e), a recess having a plurality of other modifications is provided. You can also
[Others]
The recesses 25 are not limited to being continuous in the circumferential direction, and may be formed at regular intervals. Moreover, if the overhang part 21 and the recessed part 25 are formed relatively while having the overhang part 21 to absorb the shape error, the recesses 25 to 25E are not necessarily cross sections corresponding to the overhang part 21. It need not be in shape.

  The overhang portion 21 can be deformed according to the deformation of the concave portion 25, or can be deformed by a variation of the deformation of the concave portion 25 regardless of the concave portion 25.

  The overhang portions 21 are not limited to those that are continuous in the circumferential direction, and may be formed at regular intervals.

The C-ring 17 can be prevented from coming off and locked to the overhang portion 21 by a structure in which the C-ring 17 is engaged in the attached state, or the inner peripheral surface 19 of the locking wall 15 due to impact of the C-ring 17 or the like. Any of the structures engaged when moved along
The overhang portion 21 and the concave portion 25 can be formed by cutting.

  The locking wall 15 is not limited to one that is continuous in the circumferential direction, but includes that in which slits are formed at regular intervals.

(Example 1) which is sectional drawing of a clamp. It is a principal part expanded sectional view of a clamp (Example 1). (A)-(e) is principal part sectional drawing which shows each modification of a recessed part (modification). It is a top view of a clamp (reference example). It is a top view of C ring (reference example). It is a principal part expanded sectional view of a clamp (reference example).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Clamp 3 Outer peripheral part 5 Contact part 7 Magnetic disk (disk)
15 Locking wall 17 C ring (balance ring)
19 Inner peripheral surface 21 Overhang portion 23 Inclined inner peripheral surface 25, 25A, 25B, 25C, 25D, 25E Concavity

Claims (7)

The central part is fixed to a rotating body that can be driven to rotate, and the outer peripheral part is provided with a contact part in a circular shape,
The outer peripheral portion has a locking wall of a balance ring that adjusts the rotation balance on the rotating body side in a circular shape,
On the inner peripheral side of the locking wall, it has an overhang portion that protrudes radially inward and can be locked to prevent the balance ring from coming off in the rotation axis direction,
The disk is fixedly supported on the rotating body by applying a pressing force in the direction of the rotation axis by bringing the abutting portion into contact with a disk mounted on the rotating body and capable of recording information .
A clamp disk rotating device for locking engagement escape the rotation axis direction by the overhang portion disposed above balance ring on the inner peripheral side of the locking wall,
Before bending the locking wall, a portion to be the overhang portion is formed by the thickness movement in the thickness direction by press molding of the portion to be the concave portion on the side in the thickness direction of the portion to be the locking wall. Extrusion molding,
Then, the portion to be the overhang portion was formed as the overhang portion by bending the locking wall,
A clamp for a disk rotation drive device. It is a clamp of the disk rotation drive device according to claim 1,
On the inner peripheral side of the locking wall, the overhang portion is provided,
On the outer peripheral side of the locking wall, there is a concave portion corresponding to the overhang portion,
A clamp for a disk rotation drive device. It is a clamp of the disk rotation drive device according to claim 1 or 2,
The concave portion has a cross-sectional shape having a size corresponding to the protruding amount of the overhang portion.
A clamp for a disk rotation drive device. A clamping of the disk rotation driving apparatus of any one of claims 1 to 3,
The overhang portion protrudes in the radial direction within a range of 0.1 to 0.3 mm with respect to the inner peripheral surface of the locking wall with which the balance ring abuts.
A clamp for a disk rotation drive device. A clamping of the disk rotation driving apparatus of any one of claims 1 to 4,
The overhang portion has an inclined inner peripheral surface set to be inclined in a range of 15 ° to 45 ° with respect to the rotation axis direction.
A clamp for a disk rotation drive device. A clamping of the disk rotation driving apparatus of any one of claims 1 to 5,
The height of the locking wall from the abutting portion is not more than three times the plate thickness of the clamp material and is not less than a dimension that allows the balance ring to be locked .
A clamp for a disk rotation drive device . The central part is fixed to a rotating body that can be driven to rotate, and the outer peripheral part is provided with a contact part in a circular shape,
The outer peripheral portion has a locking wall of a balance ring that adjusts the rotation balance on the rotating body side in a circular shape,
On the inner peripheral side of the locking wall, it has an overhang portion that protrudes radially inward and can be locked to prevent the balance ring from coming off in the rotation axis direction,
The disk is fixedly supported on the rotating body by applying a pressing force in the direction of the rotation axis by bringing the abutting portion into contact with a disk mounted on the rotating body and capable of recording information.
Manufacture of a clamp in which the balance ring is disposed on the inner peripheral side of the locking wall and the locking wall of the disk rotation driving device clamped and locked in the direction of the rotation axis by the overhang portion is raised by bending with a press. A method,
Before bending the locking wall, a portion to be the overhang portion is formed by the thickness movement in the thickness direction by press molding of the portion to be the concave portion on the side in the thickness direction of the portion to be the locking wall. Extrusion molding,
Thereafter, a portion to be the overhang portion is formed as the overhang portion by bending the locking wall,
The clamp manufacturing method characterized by the above-mentioned.

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