JP2003085938A - Magnetic disk unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic disk unit which allows the reduction of noise without causing the deterioration of productivity and reliability. SOLUTION: The upper surface opening of a case main body 10 housing magnetic disks 12a, 12b is closed by a plate like cover 15 which is screwed up to the case main body. The cover 15 is fixed on the case main body and, at the same time, is provided with plural fixing parts which are positioned around the magnetic disks, a radial beam part 44 which is radially molded toward the central corresponding part C confronted with the center of the magnetic disk from the neighborhood of at least one of fixation part and first and second circular beam parts 46, 48 which are molded coaxially with the central corresponding part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device provided with a magnetic disk that is rotationally driven in a sealed case.

[0002]

2. Description of the Related Art Generally, a magnetic disk device has a rectangular box-shaped case having an opening on the upper surface and a plate-shaped lid body screwed to the case by a plurality of screws to close the upper opening of the case. ing. And in the sealed case,
A magnetic disk as a recording medium, a spindle motor that supports and rotates the magnetic disk, a magnetic head that records and reproduces information on the magnetic disk, a head actuator that supports and drives the magnetic head, and a voice that drives the head actuator. A coil motor etc. are stored.

In such a magnetic disk device, while the magnetic disk is rotating, the head actuator moves and positions the magnetic head on an arbitrary radial position on the magnetic disk, that is, on an arbitrary track, and the magnetic head causes the magnetic field to move. Reads and writes information to the disc.

However, in the above magnetic disk device, since the magnetic disk continues to rotate during operation, noise is easily generated. In recent years, magnetic disk devices are often arranged in the vicinity of users, and in particular, when used for audio-visual applications, noise is a problem.

Therefore, conventionally, there is provided a device in which a damping plate material is attached to the lid of the case, or the entire lid is constructed as a damping steel plate so that the lid has a damping effect to reduce noise. It is provided. JP-A-11
Japanese Patent No. 53868 discloses a device in which a lid is formed of a special material having a large damping. Further, Japanese Patent Laid-Open No. 10-214480 discloses a device in which a reinforcing plate member is integrally formed on the inner surface of a lid.

[0006]

However, in the device in which the damping plate is attached to a part of the lid, the damping effect is relatively low, and the attaching work is troublesome, resulting in a high manufacturing efficiency. It leads to reduction. When a damping steel plate is used as the lid, the weight of the lid is large,
The weight of the entire device becomes excessive, which is a serious problem in a small magnetic disk device.

Further, when the lid is made of a special material, a very small amount of impurities may be separated from the material and fall on the magnetic disk, causing a magnetic head crash, which lowers the reliability of the apparatus. There is a fear.

The present invention has been made in view of the above points, and an object thereof is to provide a magnetic disk device capable of reducing noise without lowering productivity and reliability.

[0009]

To achieve the above object, a magnetic disk apparatus according to the present invention comprises a magnetic disk, a drive section for supporting and rotating the magnetic disk, and an information storage unit for the magnetic disk. A magnetic head for recording / reproducing, a magnetic disk, a drive unit, and a case accommodating the magnetic head are provided. The case has a case main body having an opening, and the case main body is fixed to the case main body to close the opening. And a plate-shaped lid body facing the magnetic disk, the lid body being fixed to the case body and being provided with a plurality of fixing portions located around the magnetic disk. Radial beam parts radially formed from the vicinity of the one fixed part toward the center corresponding part facing the center of the magnetic disk, and formed concentrically with the center corresponding part It is characterized by comprising, an arcuate beam section which.

According to the magnetic disk device configured as described above, the rigidity of the lid is improved and the rigidity of the lid is improved by forming the beam portion pattern having the radial beam portion and the arc-shaped beam portion on the lid body. The resonance frequency can be increased. Thereby,
The vibration amplitude and response speed when the lid is vibrated become smaller,
It is possible to significantly reduce the noise caused by the vibration of the lid.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a hard disk drive (hereinafter referred to as HDD) as a magnetic disk device will be described in detail below with reference to the drawings.

As shown in FIG. 1, the HDD is provided with a hermetically sealed flat rectangular case 11, which includes a case body 10 in the shape of a rectangular box with an open top and a plurality of screws 16.
And a lid 15 in the shape of a rectangular plate that is screwed to the case to close the upper end opening of the case.

In the case body 10, two magnetic disks 12a and 12b as magnetic recording media, and a spindle motor 1 for supporting and rotating these magnetic disks.
3. A plurality of magnetic heads 22 for recording / reproducing information on / from a magnetic disk, a head actuator 14 that movably supports these magnetic heads with respect to the magnetic disks 12a, 12b, and a head actuator for rotating and positioning. A voice coil motor (hereinafter referred to as VCM) 19, a ramp load mechanism 18 for holding the magnetic head at a position separated from the magnetic disk when the magnetic head moves to the outermost periphery of the magnetic disk, and an inertia for holding the head actuator at the retracted position. Flexible printed circuit board unit (hereinafter referred to as FPC unit) on which the latch mechanism 20 and circuit components such as a preamplifier are mounted.
17 are stored.

On the outer surface of the case body 10, an FPC is attached.
Spindle motor 13, VCM1 via unit 17
9 and a printed circuit board (not shown) for controlling the operation of the magnetic head are screwed and are located so as to face the bottom wall of the case.

Each of the magnetic disks 12a and 12b is formed, for example, to have a diameter of 65 mm (2.5 inches) and has magnetic recording layers on the upper and lower surfaces. The two magnetic disks 12a and 12b are coaxially fitted to a hub (not shown) of the spindle motor 13 and clamped by a clamp spring 21, and are stacked at a predetermined interval along the axial direction of the hub. ing. Then, the magnetic disks 12a, 12b are rotationally driven at a predetermined speed by a spindle motor 13 as a drive unit.

The head actuator 14 is a case 10
Of the bearing assembly 24 fixed on the bottom wall, four arms 27 attached to the bearing assembly, and four magnetic head assemblies 30 supported by each arm. Each magnetic head assembly 30 includes an elongated suspension formed of a leaf spring and a magnetic head 22 fixed to the suspension.

Each magnetic head 22 has an arm 27.
Also, the FPC unit 1 is mounted via the relay flexible printed circuit board (not shown) fixed to the surface of the suspension and the main flexible circuit board 32.
It is electrically connected to 7. During operation of the HDD, the head actuator 14 is rotated by the VCM 19, and the magnetic head 22 moves on the magnetic disks 12a and 12b substantially in the radial direction and is positioned on a desired track.

On the other hand, the rectangular plate-shaped lid 15 is formed by press-molding an aluminum plate having a plate thickness of about 0.4 mm, for example. Through holes 40 are formed in the four corner portions of the lid body 15 and substantially in the center of the side edge on the long side. Then, the lid body 15 is fixed to the case body by screwing the screw 16 inserted into each through hole 40 into the screw hole formed in the peripheral portion of the case body 10, and closes the upper end opening of the case body. At the same time, they face the magnetic disk 12a in a substantially parallel manner with a predetermined gap. Therefore, the portion of the lid body 15 including each through hole 40 constitutes a fixing portion for fixing the lid body to the case body 10.

Further, in the lid body 15, the bearing assembly 24
A through hole 42 is formed at a position opposed to. Then, the fixing screw 43 inserted through the through hole 42 is attached to the bearing assembly 2
A part of the lid body 15 and the bearing assembly are connected by screwing into the upper end portion of 4.

The lid body 15 is press-molded so as to form a convex portion that projects outward, excluding the peripheral edge portion, upward in FIG. The six through holes 40 are formed in the peripheral edge of the lid body 15, respectively.

Further, a beam pattern for increasing the rigidity of the lid is formed on the convex portion of the lid 15. That is, when the position corresponding to the center of the magnetic disk 12a is defined as the center corresponding portion C in the lid 15, the beam pattern is formed in the lid 15 from the vicinity of the four through holes 40 located around the magnetic disk. Four radial beam portions 44 each extending toward the center corresponding portion C, a first arcuate beam portion 46 formed in an arc shape concentric with the center corresponding portion C, and a circle concentric with the center corresponding portion C. The second arcuate beam portion 48 formed in an arcuate shape and located outside the first arcuate beam portion, and the through hole 40 provided in the central portion of one long side are provided in the vicinity of the central portion of the other long side. Through hole 4
And a linear beam portion 50 linearly extending toward 0 toward the center of the lid body.

The first and second arcuate beam portions 46 and 48 are
In order to prevent interference with the magnetic head 22, the magnetic head 2
The portion facing the movement path 2 is formed in an open arc shape. In addition, the first and second arcuate beam portions 46, 48
The widths of the center corresponding portions C in the radial direction are different from each other, and the width W1 of the first arcuate beam portion is formed wider than the width of the second arcuate beam portion W2.

In this embodiment, the width of the lid 15 is 70 m.
When the length is m, the outer diameter of the first arc-shaped beam portion 46 is 18.7 m.
m, width W1 is formed to 6.0 mm, and the second arcuate beam portion 4 is formed.
8 has an outer diameter of 28.5 mm (please check), width W2
Is formed to have a thickness of 3 mm. Width W of the first arc-shaped beam portion 46
1 is about 1.5 to 3.0 times as large as the second arcuate beam portion 48.

Of the four radial beam portions 44, the radial beam portion extending from the vicinity of the through hole 40 located at the corner portion of the lid 15 extends to the second arc-shaped beam portion 48. The remaining two radial beam portions 44 extend from the vicinity of the through hole 40 to the first arc-shaped beam portion 46 through the end of the second arc-shaped beam portion 48. Further, the linear beam portion 50 is formed from the vicinity of the through hole 40 to the first
It extends to the arc-shaped beam portion 46.

According to the HDD configured as described above,
By providing the above-described beam portion pattern on the lid body 15,
The rigidity of the lid can be increased to increase the resonance frequency of the lid. As a result, the vibration amplitude and the response speed when the lid is vibrated are reduced, and the noise caused by the vibration of the lid can be significantly reduced. For example, the HDD according to the present embodiment was able to reduce noise by about 8% as compared with the HDD including the lid body not provided with the beam portion pattern. The resonance frequency of the lid 15 varies depending on the diameter, depth and width of the beam. For example, as shown in FIG. 2, the resonance frequency of the lid body 15 changes according to the radius of the second arcuate beam portion 48, and in the present embodiment, the radius is about 24 to 2.
The best value is about 6.5 mm. In addition, the second arcuate beam portion 48
The resonance frequency can be made higher when the depth is 1.2 mm than when the depth is 0.8 mm. That is, the lid 1
In order to increase the resonance frequency of 5, the deeper the beam portion is, the more effective it is. However, if the beam portion is too deep, distortion occurs during molding of the lid,
Set appropriately considering both. Further, since the rigidity of the lid 15 is increased, the characteristics of the HDD are improved and the positioning accuracy of the magnetic head can be increased. Therefore, according to the present embodiment, it is possible to obtain an HDD capable of reducing noise without lowering productivity and reliability.

Next, the lid of the HDD according to the second and third embodiments of the present invention will be described. As shown in FIG. 3, according to the second embodiment, in the beam portion pattern formed on the lid body 15, the four radial beam portions 44 are
Both of them extend from the vicinity of the through hole 40 to the first arcuate beam part 46 through the second arcuate beam part 48.

As shown in FIG. 4, according to the third embodiment, in the beam portion pattern formed on the lid 15, the four radial beam portions 4 each extending from the vicinity of the through hole 40 are provided.
No. 4 ends with the second arcuate beam portion 48 and does not extend to the first arcuate beam portion 46. The other configurations of the second and third embodiments are the same as those of the above-described first embodiment, and the same parts are designated by the same reference numerals and detailed description thereof will be omitted. Then, also in the second and third embodiments, it is possible to obtain the same effects as those of the above-described first embodiment.

Next, a lid of the HDD according to the fourth embodiment of the present invention will be described. As shown in FIG. 5, according to the present embodiment, the beam portion pattern formed on the lid body 15 includes the beam pattern from the vicinity of the through hole 40 located at the center of each long side of the lid body to the center of the lid body 15. Two radial beam portions 44 each extending toward the corresponding portion C, a single arc-shaped beam portion 52 formed in an arc shape concentric with the center corresponding portion C, and provided in the central portion of one long side The linear beam portion 50 linearly extends from the vicinity of the through hole 40 to the through hole 40 provided at the center of the other long side to almost the center of the lid.

The arcuate beam portion 52 has an outer diameter of 24.
5mm, inner diameter 12.8mm, radial width W is about 1
The magnetic head 2 has a wide width of 2 mm.
In order to prevent interference with the magnetic head 22, the portion facing the movement path of the magnetic head 22 is formed in an open arc shape.

The beam portion pattern has an arcuate connecting beam portion 54 formed along the inner edge of the arcuate beam portion 52 and formed in the open portion of the arcuate beam portion 52. The radial width of the part is set to about 3.0 mm. The other configurations of the fourth embodiment are the same as those of the first embodiment described above, and the same portions are denoted by the same reference numerals and detailed description thereof will be omitted. Then, also in the fourth embodiment, it is possible to obtain the same effects as those of the above-described first embodiment.

Further, the resonance frequency of the lid 15 varies depending on the depth and width of the arcuate beam portion 52. For example, as shown in FIG. 6, the resonance frequency of the lid body 15 can be increased as the arcuate beam portion 52 is deepened. However, the arcuate beam 5
If 2 is too deep, distortion occurs when the lid 15 is molded,
Set appropriately.

As shown in FIG. 7, according to the HDD lid of the fifth embodiment of the present invention, the beam pattern is
A small-diameter circular beam portion 56 formed in a circular shape concentric with the center corresponding portion C, and four through holes 40 located around the magnetic disk.
4 radial beam portions 44 respectively extending from the vicinity of to the center beam corresponding to the center C of the lid body 15 to the circular beam portion, and three regions surrounded by the radial beam portions 44, which are formed on the side of the lid body 15 respectively. Three straight beam portions 60 extending substantially parallel to the edge,
A linear beam portion 50 linearly extending from the vicinity of the through hole 40 provided in the central portion of one long side to the vicinity of the through hole 40 provided in the central portion of the other long side, and a bearing assembly. A V-shaped beam portion 62 that extends from the vicinity of the through hole 42 for fixing the solid body to the vicinity of the through hole 40 located at the center of one long side of the lid and the corner portion, and has a V shape. ing.

The other structure of the fifth embodiment is the same as that of the above-described first embodiment, and the same parts are designated by the same reference numerals and the detailed description thereof will be omitted. In addition, also in the fifth embodiment, it is possible to obtain the same effects as those of the above-described first embodiment.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention. For example, the material and size of the lid can be variously selected as required. In addition, this invention is 2.5 inches H
The present invention can be applied to not only DD but also 3.5-inch and 1.8-inch HDDs.

[0035]

As described in detail above, according to the present invention, the beam pattern is formed on the lid, so that noise can be reduced without lowering productivity and reliability. Can be provided.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an HDD according to a first embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the resonance frequency of the lid of the HDD and the radius and depth of the beam pattern.

FIG. 3 is a perspective view showing an HDD cover body according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing an HDD cover according to a third embodiment of the present invention.

FIG. 5 is a perspective view showing an HDD cover according to a fourth embodiment of the present invention.

FIG. 6 is a graph showing the relationship between the resonance frequency of the lid of the HDD according to the fourth embodiment and the depth of the beam pattern.

FIG. 7 is a perspective view showing a lid of an HDD according to a fifth embodiment of this invention.

[Explanation of symbols]

12a, 12b ... Magnetic disk 14 ... Head actuator 15 ... Lid 16 ... Fixing screw 22 ... Magnetic head 24 ... Bearing assembly 30 ... Magnetic head assembly 40 ... through hole 44 ... Radial beam part 46 ... First arc-shaped beam portion 48 ... Second arc-shaped beam portion 50, 60 ... Straight beam part 52 ... Arc beam

Claims (9)

[Claims] 1. A magnetic disk, a drive section for supporting and rotating the magnetic disk, a magnetic head for recording and reproducing information on the magnetic disk, a magnetic disk, a drive section, and a magnetic head. The case includes a case body having an opening, and a plate-shaped lid body fixed to the case body and closing the opening and facing the magnetic disk, The lid body is fixed to the case main body, and extends from the vicinity of at least one of the plurality of fixing portions located around the magnetic disk to the center corresponding portion facing the center of the magnetic disk. A magnetic disk device, comprising: a radial beam portion radially formed by an arc and a circular arc beam portion concentric with the center corresponding portion. 2. The lid body is formed with a first arcuate beam portion formed concentrically with the center corresponding portion, and located outside the first arcuate beam portion formed concentrically with the center corresponding portion. 2. The magnetic disk device according to claim 1, further comprising a second arcuate beam portion. 3. The magnetic disk device according to claim 2, wherein the first and second arcuate beam portions have different widths in the radial direction of the center corresponding portion. 4. The width of the first arcuate beam portion along the radial direction of the center corresponding portion is formed wider than the width of the second arcuate beam portion along the radial direction of the center corresponding portion. 4. The magnetic disk device according to claim 3, wherein 5. The lid body includes a plurality of radial beam portions extending from the vicinity of the plurality of fixing portions to the second arc-shaped beam portion. 2. The magnetic disk device according to item 1. 6. The lid body includes a plurality of radial beam portions extending from the vicinity of the plurality of fixing portions to the second arc-shaped beam portion and extending to the first arc-shaped beam portion. The magnetic disk device according to claim 2, wherein the magnetic disk device is a magnetic disk device. 7. The magnetic disk drive according to claim 1, wherein the lid includes a plurality of the radial beam portions extending from the vicinity of the plurality of fixing portions to the arc-shaped beam portions. . 8. The lid body is provided with a linear beam portion linearly extending from the vicinity of one fixing portion to another fixing portion among the plurality of fixing portions. The magnetic disk device according to claim 1. 9. The arcuate beam portion is formed in an arcuate shape in which a portion facing the moving path of the magnetic head with respect to the magnetic disk is open. The magnetic disk drive according to the item.