JP2001110151A - Actuator for hard disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a structure capable of reducing air resistance during the rotation of an actuator. SOLUTION: This actuator is produced by integrally resin-molding a supporting part 2 rotatably supported by a shaft provided near a magnetic disk, a swing arm 3 extended from the supporting part 2 in one direction and having a magnetic head attached to its tip, and a coil holding part 4 for holding a driving voice coil 5. In this case, the swing arm 3 is formed in a shape to be gradually thinner from the center of a width direction to both sides, and a thickness is gradually reduced from the swing arm 3 toward the arm tip. Thus, air resistance during the rotation of the actuator is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary actuator used in a hard disk drive having a built-in magnetic disk.

[0002]

2. Description of the Related Art Hard disk drives (HDDs)
It is mainly used as an auxiliary storage device for personal computers, and recently, a product having a capacity of 20 GB class has appeared. In addition, the speed of writing / reading has also been rapidly increasing, and with this, magnetic disk rotation speeds of 3600 rpm to 7200 rpm and ultra-high speed products of 10,000 rpm have been developed. Has appeared.

As shown in FIG. 17, a hard disk drive has a magnetic disk 20 having a magnetic layer formed on its surface.
0, a magnetic head 202 for writing / reading data to / from the magnetic disk 200, and an actuator 201 for displacing the magnetic head 202. The actuator 201 is, for example, a processed aluminum product (surface electroless Ni plating), and is rotatably supported by a pivot shaft 203 provided near the magnetic disk 200.
Voice coil 2 provided on the opposite side of magnetic head 202
15 and permanent magnet 204 provided on the HDD housing side
, The swing arm 213 swings, and the magnetic head 202 at the tip moves to a predetermined track on the magnetic disk 200.

In general, one hard disk drive contains two to ten magnetic disks.

[0005]

By the way, in the conventional actuator, after extruding aluminum, for example, into the projected shape of the actuator (outer shape in the plan view of FIG. 17), the molded product is formed into a block having a predetermined thickness. After cutting, each block is processed into a shape as shown in FIG. 18 by cutting or the like, and burrs at the corners of the processed product are removed by hand finishing. Therefore, there is a problem that the number of manufacturing steps is large and the material yield is very poor.

Further, since the product is a cut product such as aluminum, the swing arm 213 and the coil holding portion 214 are formed.
In order to process the side surface into a round shape, extra man-hours and cost are required, so as described above, only finishing such as removing burrs at the corners of the processed product is performed,
At present, the side surfaces of the swing arm 213 and the coil holding portion 214 are flat end surfaces. For this reason,
In the current actuator, the air resistance generated by the side surfaces of the swing arm 213 and the coil holding portion 214 increases during use (when the actuator rotates).
Such air resistance affects the position control of the magnetic head, and the air resistance becomes more remarkable as the moving speed of the actuator becomes higher. It will be a challenge in.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inexpensive actuator for a hard disk drive having a structure in which air resistance during rotation is small.

[0008]

SUMMARY OF THE INVENTION An actuator of the present invention is a rotary actuator used for a hard disk drive having a built-in magnetic disk, and is supported rotatably on a shaft provided near the magnetic disk. Part, a swing arm extending in one direction from the support part and having a magnetic head attached to the tip thereof, and a coil holding part for holding a voice coil for driving, and the support part, the swing arm and the coil holding part are formed by resin molding. The swing arm is characterized in that it is integrally formed, and is formed in such a shape that the wall thickness is reduced toward both ends in the width direction. Note that the width direction of the swing arm refers to a direction orthogonal to the direction in which the swing arm extends from the support.

Further, the actuator of the present invention is a rotary actuator used for a hard disk drive having a built-in magnetic disk, wherein the support portion is rotatably supported by a shaft provided near the magnetic disk, A swing arm extending in one direction from the part and having a magnetic head attached to the tip, and a coil holding part for holding a voice coil for driving, the support part, the swing arm and the coil holding part are integrally formed by resin molding. In addition, the swing arm is characterized in that it is formed in a shape in which the wall thickness is reduced toward the tip of the arm.

According to the actuator of the present invention, as a product in which the supporting portion, the swing arm and the coil holding portion are integrally formed by resin molding, the shape of the swing arm is
A shape in which the wall thickness is reduced toward both ends in the width direction,
Or, because the wall thickness is reduced toward the arm tip, the flat end face can be eliminated on the side of the swing arm, or the area of the flat side end face can be reduced, and the air resistance when the actuator rotates can be reduced. can do.

It is also possible to form the side surface of the coil holding portion into a round shape by using a resin molded product for the actuator. By adopting such a configuration, the air resistance during rotation of the actuator is further reduced. Can be smaller.

Here, in the actuator of the present invention, the shape of the swing arm is such that the thickness is reduced toward both ends in the width direction, and the thickness is reduced toward the tip of the arm. Either of the two configurations may be employed, or one of the configurations may be employed.

By the way, in a hard disk drive actuator, a control element or a connection terminal is generally provided on a support portion, and the control element or the connection terminal is connected to a magnetic head via a wiring (lead wire). In order to avoid interference with the hard disk, a method of arranging the lead wire on the side of the swing arm and fixing it with an adhesive or adhesive tape has been adopted, but such wiring work is complicated, In addition, since it is performed manually, there is a problem that it takes a considerable amount of time.

In order to solve such a problem, in the actuator according to the present invention, a concave portion for accommodating and holding the wiring for connection with the magnetic head is provided along the side peripheral edge of the swing arm to perform wiring work. For simplicity.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention.
FIG. 2 is a plan view (A) and a side view (B) of the embodiment. 3 is a sectional view taken along line CC of FIG. 2, and FIGS. 4 and 5 are a sectional view taken along line DD and EE of FIG. 2, respectively.

The actuator 1 of this embodiment has a support portion 2 rotatably supported via a sleeve or the like on a pivot shaft 103 (see FIG. 17) provided in the vicinity of the magnetic disk, and one direction from the support portion 2. 3 and a coil holding portion 4 protruding from the support portion 2 on the opposite side to the swing arm 3. The support portion 2, the swing arms 3. The part 4 is integrally formed by injection molding of a resin.

At the end of each swing arm 3, a mounting hole 3a for fixing a gimbal (not shown) of the magnetic head is formed.

The coil holding section 4 is a C-shaped member having an open end, and a voice coil 5 is mounted inside thereof. As shown in FIG. 3, a concave portion 4 a extending at a constant width and depth along the inner peripheral edge of the coil holding portion 4 is formed inside the coil holding portion 4 (coil mounting surface),
Further, at the center of the concave portion 4a, a convex portion 4b extending at a constant height along the inner peripheral edge is also integrally formed. The width W (see FIG. 3) of the concave portion 4a is processed to the same size as the thickness of the voice coil 5 attached to the coil holding portion 4 or a size smaller by a predetermined amount. The coil holding unit 4
The dimensions of each part of the actuator 1 including the concave part 4a and the convex part 4b are machined based on the accuracy required in the hard disk drive.

On the other hand, on the outer peripheral surface of the voice coil 5, a fitting recess 5 having a shape and size corresponding to the projection 4b of the coil holding portion 4 is provided.
b is provided. The fitting recess 5b can be easily realized by devising a winding method of the coil.

In the actuator 1 of the present embodiment, as shown in FIGS. 4 and 5, the shape of each swing arm 3 is reduced in thickness from the center in the width direction to both ends. In addition, it is characterized in that the wall thickness is reduced from the support portion 2 toward the tip of the arm 3, and the outer peripheral surface of the coil holding portion 4 is formed in a round shape. The air resistance at the time can be reduced.

Further, by forming the swing arm 3 as described above, the formability of the swing arm 3 can be improved.

That is, when the actuator 1 including the support portion 2, the swing arm 3, and the coil holding portion 4 is integrally formed (injection-molded), the flow of the molten resin in the mold is caused by the thick support portion. In general, it is set to flow from 2 to the tip of each swing arm 3,
In molding such a resin flow, the swing arm 3
If the thickness of the shape is made smaller toward the tip from the base portion (support portion 2 side), the molding fluidity becomes better and the moldability becomes better as compared with the case where the thickness is constant. improves. As a result, the dimensional accuracy of the swing arm 3 can be improved. Furthermore, if the thickness is reduced from the center in the width direction of the swing arm 3 toward both sides, the molding fluidity in the width direction of the swing arm 3 is improved, and the dimensional accuracy is further improved.

According to the actuator 1 having the structure shown in FIGS. 1 to 3, the voice coil 5 is attached to the concave portion 4a of the coil holding portion 4, and the voice coil 5 is attached to the convex portion 4b in the concave portion 4a.
By fitting with the fitting recesses 5b of
The voice coil 5 can be accurately positioned with respect to the actuator 1. Further, the voice coil 5 is sandwiched between the concave portions 4 a of the coil holding portion 4,
Since the protruding portion 4b in FIG. 4a is fitted in the fitting concave portion 5b of the voice coil 5, the fixing force of the voice coil 5 is increased by fitting these members, and the voice coil 5 is more securely held. There is also the advantage that it can be done.

Here, the cross section of the swing arm 3 in the width direction is not only the shape (streamline) shown in FIG. 4 but also a rhombus as shown in FIG. 6 (A) or FIG. 6 (B). As described above, a shape in which both side end portions are formed in a round shape to reduce the thickness at the side end portions, and the like can be given.

FIGS. 7 and 8 are a perspective view and a plan view, respectively, of another embodiment of the actuator of the present invention. FIG.
10 and FIG. 10 are a sectional view taken along line FF and a sectional view taken along line GG of FIG. 8, respectively.

In the actuator 11 of this embodiment, the swing arms 3... 3 having the same shape as those of the previous embodiment are supported by the support 2, and the support 1, the swing arms 3. It is characterized in that the voice coil 5 is embedded in the coil holding part 14 by insert molding, while the voice coil 5 is integrally formed by resin injection molding.

As described above, by embedding the voice coil 5 in the coil holding portion 14 by insert molding, the step of attaching the voice coil 5 can be omitted. In addition, by ensuring the positioning accuracy of the voice coil 5 with respect to the insert molding die, the voice coil 5 can be accurately positioned with respect to the actuator body after molding.

In this embodiment, FIGS. 9 and 10
As shown in the figure, the shape of the coil holding portion 14 is a shape in which the wall thickness is reduced from the center in the width direction toward both ends,
In addition, since the thickness is reduced as the distance from the support portion 2 increases, the air resistance in the coil holding portion 14 can be significantly reduced as compared with the conventional product (see FIG. 18).

FIG. 11 is a plan view of another embodiment of the present invention. 12 and 13 are a sectional view taken along the line HH and a sectional view taken along the line II of FIG. 11, respectively.

The actuator 101 of this embodiment is
In the actuator 11 having the structure shown in FIGS. 7 and 8, the coil holding portion 104 in which the voice coil 5 is embedded by insert molding is formed into a shape (ring shape) corresponding to the voice coil 5, and It is characterized by its light weight.

FIG. 14 is a side view of still another embodiment of the present invention. FIG. 15 is a JJ cross-sectional view of FIG.

The actuator 111 of this embodiment is characterized in that a concave portion 13b is provided along one peripheral edge of one of both side portions of each swing arm 13. The recess 13 b can accommodate and hold a lead wire 6 that connects a magnetic head (see FIG. 17) attached to the tip of the swing arm 13 and a control element (not shown) provided on the support 2. By providing such a concave portion 13b, the lead wire 6 can be held by the swing arm 13 only by fitting the lead wire 6 into the concave portion 13b. It's easy. When the lead wire 6 is held in the recess 13b, it may be fixed with an adhesive if necessary.

The recess 13 for housing and holding the wiring as described above
b may be formed along the peripheral edges of both sides of the swing arm 13 as shown in FIG.

In the embodiment shown in FIG. 14, the swing arm 13 having a constant thickness in the longitudinal direction is provided with the concave portion 13b for accommodating and holding the wiring. However, as shown in FIG. A similar recess 13b for accommodating and holding wiring can be formed on the swing arm 3 having a shape whose thickness is reduced from the portion toward the tip.

Here, it has been confirmed at present that a product excellent in dimensional accuracy and reliability can be obtained even when the actuator is an integrally molded product of resin as in the above embodiment. By making the actuator a resin molded product, the product cost can be significantly reduced. Moreover, since the weight of the actuator can be reduced, the driving force of the linear motor can be reduced, and the controllability of the position control of the magnetic head can be further improved.

As described above, in the conventional actuator, as described above, for example, after extrusion molding of aluminum, the molded product is cut into blocks having a predetermined thickness, and then each block is subjected to cutting or the like as shown in FIG. It is manufactured in the process of processing into a shape, removing the burrs and the like at the corners of the processed product by hand finishing, and then preparing the surface of the product and performing electroless plating of Ni, so that the number of manufacturing steps is large, and However, there has been a problem that the material yield is very poor, but these problems can be solved all at once by using a resin molded product for the actuator.

[0038]

As described above, according to the actuator of the present invention, the support portion rotatably supported by the shaft provided in the vicinity of the magnetic disk, the magnetic head extending in one direction from the support portion and having the magnetic head at the tip end. As a product in which the swing arm to which is mounted and the coil holding portion for holding the driving voice coil are integrally formed of resin, the swing arm is formed into a shape in which the thickness is reduced toward both ends in the width direction, and Since the swing arm is formed in a shape in which the wall thickness decreases toward the tip of the arm, the air resistance during rotation of the actuator can be reduced. As a result, the position controllability of the magnetic head is improved, and it is easy to cope with an increase in the write / read speed. In addition, since the actuator is formed as an integrally molded product of resin, the product cost is reduced as compared with, for example, an actuator made of aluminum.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a plan view (A) and a side view (B) of the embodiment of the present invention.

FIG. 3 is a sectional view taken along line CC of FIG. 2;

FIG. 4 is a sectional view taken along line DD of FIG. 2;

FIG. 5 is a sectional view taken along line EE of FIG. 2;

FIG. 6 is a sectional view showing a modification of the swing arm.

FIG. 7 is a perspective view of another embodiment of the present invention.

FIG. 8 is a plan view of another embodiment of the present invention.

FIG. 9 is a sectional view taken along line FF of FIG. 8;

FIG. 10 is a sectional view taken along line GG of FIG. 8;

FIG. 11 is a plan view of another embodiment of the present invention.

FIG. 12 is a sectional view taken along the line HH in FIG. 11;

FIG. 13 is a sectional view taken along line II of FIG. 11;

FIG. 14 is a side view of a main part of still another embodiment of the present invention.

FIG. 15 is a sectional view taken along the line JJ of FIG. 14;

FIG. 16 is a cross-sectional view showing a modification of the embodiment shown in FIG.

FIG. 17 is a diagram schematically showing a main structure of a hard disk drive.

18 is a perspective view of an actuator (conventional product) used for the hard disk drive of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Actuator 2 Support part 3, 13 swing arm 3a Mounting hole (for magnetic head mounting) 13b Depression (for wiring accommodation / holding) 4 Coil holding part 4a Depression 4b Convex part 5 Voice coil 5b Fitting concave

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi New Year 2F, 1-7-7 Higashi Nara, Ibaraki-shi, Osaka F-term (reference) 5D068 AA01 BB02 CC12 EE18 EE19 GG03

Claims (3)

[Claims] 1. A rotary actuator used for a hard disk drive having a built-in magnetic disk, comprising: a support portion rotatably supported by a shaft provided near the magnetic disk; and a support extending in one direction from the support portion. It consists of a swing arm with a magnetic head attached to the tip and a coil holding part for holding a voice coil for driving.The supporting part, swing arm and coil holding part are integrally formed by resin molding, and the swing arm is ,
An actuator for a hard disk drive, characterized in that the actuator is formed in a shape in which the wall thickness is reduced toward both ends in the width direction. 2. A rotary actuator for use in a hard disk drive having a built-in magnetic disk, comprising: a support portion rotatably supported by a shaft provided near the magnetic disk; and a support extending in one direction from the support portion. It consists of a swing arm with a magnetic head attached to the tip and a coil holding part for holding a voice coil for driving.The supporting part, swing arm and coil holding part are integrally formed by resin molding, and the swing arm is ,
An actuator for a hard disk drive, characterized in that the actuator is formed in a shape in which the wall thickness decreases toward the end of the arm. 3. A concave portion for accommodating and holding wiring from a magnetic head attached to a tip of a swing arm to a support portion side is formed along a side peripheral edge of the swing arm. Item 3. An actuator for a hard disk drive according to item 1 or 2.