JP3710576B2 - Disk unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention generally relates to disk devices, and more particularly to a housing cover structure of a disk device.
[0002]
Generally, in a magnetic disk device for a computer, in order to prevent a head crash, a magnetic disk, a head, and the like are sealed in a housing (housing) composed of a base and a cover, and the housing cover is provided at a low cost. It is hoped to do.
[0003]
[Prior art]
The case of a conventional magnetic disk device is configured by fixing an aluminum cover to an aluminum base with screws. The base and cover are manufactured by aluminum die casting.
[0004]
As described above, since the conventional case cover is manufactured by die-casting aluminum and has high rigidity, the actuator and the motor assembly are screwed to the base and screwed to the cover. Fixing via a diaphragm was not necessary.
[0005]
The aluminum cover was manufactured by the following manufacturing process.
Die-cast molding-Deburring-Annealing-Cleaning-Rust-proof coating-Flange drilling-Cutting-Cleaning.
[0006]
Conductive grounding with the base was applied to the entire surface of the cover with anti-corrosion coating, and then the screw tightening flange was cut to provide a metal surface to provide a conductive ground between the cover and the base.
[0007]
[Problems to be solved by the invention]
As shown in the manufacturing process described above, an aluminum cover has many secondary processing steps, and thus has a drawback of high cost and heavy weight. In addition, the aluminum cover is likely to warp due to the change in thickness. When warping occurs, there is a problem that correction is difficult.
[0008]
The present invention has been made in view of these points, and an object of the present invention is to provide a disk device including a resin cover that can be manufactured at low cost and has an electromagnetic shielding function.
[0009]
[Means for Solving the Problems]
According to the present invention, a housing including a base and a cover fixed to the base, a disk medium rotatably accommodated in the housing, a head for recording / reproducing information on the disk medium, and the disk In a disk device comprising a motor assembly for rotating a medium and an actuator rotatable about a fixed shaft for moving the head in a substantially radial direction of the disk medium, the cover is made of a resin molded body. The at least the outer surface of the resin cover is subjected to a conductive treatment, and is screwed to the upper end of the motor assembly mounted on the base and fixed to the base and the upper end of the fixed shaft fixed to the base. while being, this having a damping plate fixed on the resin cover by engagement of the screw Disk apparatus is provided, wherein.
[0010]
In the present invention, since the conductive treatment is applied to at least the outer surface of the resin cover, the resin cover can have an electromagnetic shielding function. Furthermore, since the motor assembly and the actuator are fixed to the damping plate, stable fixation can be ensured by the rigidity of the damping plate.
[0011]
Instead of conducting the conductive treatment on at least the outer surface of the resin cover, a metal plate having substantially the same shape as the resin cover may be placed on the resin cover, and the damping plate may be fixed thereon. Similarly, a film whose surface is substantially the same shape as the resin cover may be covered with a resin cover, and the damping plate may be fixed thereon.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
First, a magnetic disk device according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the magnetic disk device of the first embodiment, and FIG. 2 is a perspective view of a cover used in the first embodiment.
[0013]
Reference numeral 2 denotes a housing (housing) composed of an aluminum base 4 and a resin cover 6. A motor assembly 10 is fixed on the base 4.
[0014]
The motor assembly 10 includes, for example, an inner hub motor. The inner hub motor rotates the spindle hub around the fixed shaft.
[0015]
Reference numeral 8 denotes a magnetic disk, which is rotated by the motor assembly 10. The magnetic disk 8 is fixed to, for example, the spindle hub described above.
Reference numeral 12 denotes a rotary actuator, which is rotatably mounted around a shaft 13 fixed to the base 4 via a pair of bearings 15. A plurality of actuator arms 14 extend in one direction from the center of rotation.
[0016]
The actuator 12 has a coil 17 attached to the opposite side of the actuator arm 14 with respect to the rotation center, and a magnetic circuit (not shown) and the coil 17 constitute a voice coil motor.
[0017]
A magnetic head 16 for recording / reproducing information with respect to the magnetic disk 8 is attached to the tip of each actuator arm 14. When a voice coil motor (not shown) is driven, the actuator 12 is swung around the fixed shaft 13 and the magnetic head 16 is moved in the substantially radial direction of the magnetic disk 8.
[0018]
The cover 6 is a synthetic resin molding, and a conductive film 7 is formed on the surface thereof as shown in FIG. The conductive film 7 is formed by alternately ion-plating copper and nickel, for example. Preferably, the conductive film 7 is formed by a multilayer ion plating process of three or more layers.
[0019]
When the multilayer conductive film 7 is formed, pinholes are reduced and the generation of gas from the resin is suppressed. Further, since the ion plating process is performed in a vacuum chamber, there is an effect that gas from the resin is released in advance during the ion plating process.
[0020]
In the present embodiment, the conductive film 7 is formed by ion plating, but the conductive film 7 may be formed by electroless plating. Moreover, although the conductive film 7 is formed on the entire outer surface of the resin cover 6, the conductive film 7 may be formed on the entire inner surface of the cover 6 instead.
[0021]
In this embodiment, since the conductive film 7 is formed on the entire outer surface or inner surface of the resin cover 6, the resin cover 6 can have an electromagnetic shielding effect.
As shown in the cover perspective view of FIG. 2, the cover 6 has six flanges 26 (only four are shown), and each flange 26 is integrally formed with a boss 28. As shown in FIG. 3, the resin cover 6 is fixed to the base 4 by inserting screws 30 into the bosses 28 and tightening the screws 30 against the base 4.
[0022]
Since the conductive film 7 is formed on the surface of the resin cover 6 by ion plating or the like, the resin cover 6 is grounded to the aluminum base 4 via the screw 30.
[0023]
Reference numeral 20 denotes a damping plate made of iron. As best shown in FIG. 1, the upper end portion of the motor assembly 10 and the upper end portion of the fixed shaft 13 of the actuator 12 are damped by screws 22 and 24, respectively. It is fixed to the plate 20. Reference numeral 18 denotes an external circuit board of the magnetic disk device.
[0024]
According to the present embodiment, since the cover 6 is made of resin, its rigidity is somewhat inferior to that of an aluminum cover, but the upper ends of the motor assembly 10 and the actuator 12 are fixed to the vibration damping plate 20. The rigidity of the damping plate 20 can ensure stable fixation of the motor assembly 10 and the actuator 12.
[0025]
Referring to FIG. 4, a housing portion of a magnetic disk device according to a second embodiment of the present invention is shown. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals.
[0026]
Reference numeral 34 denotes an internal mounting portion on which the magnetic disk 8, the motor assembly 10, and the actuator 12 similar to those in the first embodiment are mounted, but their illustration is omitted.
[0027]
The housing 2 ′ of the present embodiment has an aluminum base 4 covered with a resin cover 6, and a metal plate 32 such as an iron plate cut into approximately the same shape as the resin cover 6 is placed on the resin cover 6. The resin cover 6 and the metal plate 30 are fastened together with screws 30 and fixed to the base 4.
[0028]
Further, although not shown in the drawings, it is desirable that the same damping plate 20 as in the first embodiment is placed on the metal plate 32 and the upper ends of the motor assembly 10 and the actuator 12 are fixed to the damping plate.
[0029]
As a modification of the second embodiment, instead of the metal plate 32, a film whose surface is subjected to conductive treatment by plating or ion plating may be covered so as to cover the entire surface of the resin cover 6. In this case, the resin cover 6 and the film are fastened together with screws 30 to be fixed to the base 4.
[0030]
【The invention's effect】
According to the present invention, fitted with a damper plate to the resin cover which is conductive treatment at least the outer surface, since so as to fix the upper end portion of the motor assembly and the actuator to the damper plate, also in the case where the resin cover A sufficient electromagnetic shielding function can be exhibited, and stable fixing of the motor assembly and the actuator can be ensured by the rigidity of the damping plate.
[0031]
A similar electromagnetic shield function can be achieved by covering the surface of the resin cover with a metal plate or a conductive film instead of the conductive treatment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment of the present invention.
FIG. 2 is a perspective view of the cover according to the first embodiment.
FIG. 3 is a cross-sectional view of a fixing part to a base of a cover.
FIG. 4 is a cross-sectional view of a second embodiment of the present invention.
[Explanation of symbols]
2 Housing 4 Base 6 Resin cover 7 Conductive film 8 Magnetic disk 10 Motor assembly 12 Actuator 16 Magnetic head 20 Damping plate 32 Metal plate

Claims (3)

A housing comprising a base and a cover fixed to the base, a disk medium rotatably accommodated in the housing, a head for recording / reproducing information on the disk medium, and a motor for rotating the disk medium In a disk device comprising an assembly and an actuator rotatable about a fixed shaft for moving the head in a substantially radial direction of the disk medium,
The cover is composed of a resin molded body, and at least the outer surface of the resin cover is subjected to a conductive treatment,
The resin cover is mounted on the resin cover and fixed to the upper end of the motor assembly fixed to the base and the upper end of the fixed shaft fixed to the base. A disk device comprising a vibration damping plate fixed to the disk. Instead of conducting the conductive treatment on the resin cover, after covering the resin cover with a metal plate having substantially the same shape as the cover,
2. The disk device according to claim 1, wherein the damping plate is fixed on the metal plate. Instead of conducting the conductive treatment on the resin cover, after covering the resin cover with a film that has been subjected to a conductive treatment on the surface having the same shape as the cover,
2. The disk apparatus according to claim 1, wherein the damping plate is fixed on the film.

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