JPH05151764A - Chassis structure in disk drive device - Google Patents

Abstract

PURPOSE:To improve the rigidity of a chassis and to reduce mechanical resonance due to the deficiency of the rigidity by disposing a beam member on a face not covered with the wall part of the chassis. CONSTITUTION:The beam member 10 is disposed on the opening face of the chassis 2 along the longitudinal direction of the chassis 2 and whose end parts are also fixed to side wall parts 2b and 2c. The end part of the beam member 10 in the state of being abutted on the inside surface side of the chassis 2 is fixed by a screw from the outside surface of the chassis 2 as a fixing means. In other manner, the end part of the beam member 10 inserted into a fixed recessed part formed on the chassis 2 is fixed by the screw. Thus, the influence of the mechanical resonance in a disk drive device is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a chassis for supporting its mechanical parts in a disk drive device.

[0002]

2. Description of the Related Art First, the structure of a disk drive device will be briefly described with reference to FIG. In the figure, 1 is a whole disk drive device, 2 is a chassis on which the mechanical parts are supported, and this chassis 2 is made of light metal such as aluminum, and its shape has five walls as shown in FIG. 6A. The upper wall 2a and the side walls 2b to 2e) are closed so that one surface (the lower surface) is opened, or four surfaces are wall (the upper wall 2a and the side wall 2b to
It is closed by 2d) and has a box shape with two surfaces (the lower surface and one side surface) open.

A spindle motor 3 is fixed in the box-shaped chassis 2, and a spindle shaft 3a of the spindle motor 3 projects through the hole in the upper wall portion 2a toward the upper surface of the chassis 2 and its tip end portion. A turntable 4 is attached to the turntable 4, and a disc D is placed on the turntable 4 and is rotationally driven. An optical head 5 for reading a signal recorded on the disk D or recording a signal on the disk D is arranged in the chassis 2. The optical head 5 is a window hole of the upper wall portion 2a of the chassis 2. It is adapted to be opposed to the recording surface of the disk D via the and to be moved in the radial direction of the disk D by a feed mechanism configured inside the chassis 2.

[0004]

In recent years, in such a disk drive device, the thickness of the chassis has been made thinner in accordance with the trend toward smaller size and lighter weight, but on the contrary, the rigidity of the chassis is largely sacrificed. It is the current situation. The influence of mechanical resonance due to insufficient rigidity of the chassis cannot be ignored as the performance of the device becomes higher. That is, when the rigidity of the chassis is low, resonance occurs due to the vibration accompanying the high-speed rotation of the spindle motor, and thus stable recording or reproduction of signals cannot be performed. Figure 7A
F are various vibration modes found as a result of the vibration analysis of this chassis.

As a countermeasure against this, at present, a slit is formed in the chassis around the spindle motor, which is a vibration source in the disk drive device, and the transmission of the vibration is cut off to suppress the resonance. In addition to reducing the strength, it does not fundamentally block the vibration transmission path, so it may not be applicable depending on the conditions.

The present invention has been made in view of the above points,
An object of the present invention is to provide a chassis structure that can surely suppress resonance with a simple structure.

[0007]

In order to achieve the above object, the present invention is directed to a chassis for supporting the components of a disk drive mechanism made of metal such as aluminum, the chassis having five or four walls. In a disk drive device formed in a box shape closed by a portion, a required number of beam members are bridged over a surface not covered by the wall of the chassis.

[0008]

As described above, the rigidity of the chassis is improved by bridging the beam members on the box-shaped chassis in this manner, so that the amplitude of resonance can be reduced, and the resonance frequency may be slightly shifted. Therefore, the influence of resonance can be suppressed to a small level.

[0009]

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

1 and 2 show a first embodiment of the present invention. At present, the most problematic mechanical resonance is bending vibration in the longitudinal direction of the chassis 2. Therefore, in this example, as shown in FIG. 1, the beam member 10 is bridged over the open surface of the chassis 2 along the longitudinal direction of the chassis 2, and both end portions thereof are fixed to the side wall portions 2b and 2d, respectively. As a fixing means of the beam member 10 to the chassis 2, as shown in FIG. 2A, the beam member 10 is fixed from the outer surface side of the chassis 2 with a screw 11 while the end surface of the beam member 10 is in contact with the inner surface side of the chassis 2. A method or a method of fixing the beam member 10 to the chassis 2 with the screw 11 in a state where the end of the beam member 10 is fitted in the fixing recess 12 formed in the chassis 2 as shown in FIG. Further, the fixing method is not limited to the screw, and welding or adhesion may be used.

By thus extending and fixing the beam member 10 in the longitudinal direction of the chassis 2, the rigidity of the chassis 2, particularly the bending rigidity in the longitudinal direction thereof is improved, and thereby the amplitude of resonance can be reduced. it can. It is also possible that the resonance frequency of the chassis 2 moves, although it is slight. Therefore, the influence of resonance on the spindle motor and the optical head supported by the chassis 2 is reduced, and as a result, stable recording or reproducing operation is performed.

Incidentally, in the drawings of this example, an example in which the present invention is applied to a box-shaped chassis whose five faces are closed by walls is shown in FIG.
It is needless to say that the present invention can be applied to a box-shaped chassis whose four surfaces are closed by wall portions as shown in B.

3 and 4 show a second embodiment. In this example, in the box-shaped chassis 2 whose five faces are closed by the wall portions, the beam members 10 are fixed by bridging the beam members 10 in the longitudinal direction as in the above-described first embodiment, and in the direction orthogonal to this. That is, the two beam members 10 are laid across and fixed in the lateral direction as well. In this case, in the intersecting portion of the beam member 10, as shown in FIG.
3 may be provided.

Since the beam member 10 is laid across and fixed also in the lateral direction of the chassis 2 as described above, the rigidity of the chassis 2 is further improved, and the effect of reducing resonance in the torsional direction can be obtained.

[0015]

As described above, according to the present invention, the chassis for supporting the components of the disk drive mechanism is made of metal, and the chassis is formed in a box shape having five or four surfaces closed by the wall portions. In the disk drive device, the beams are erected on the surface not covered by the wall of the chassis, so that the rigidity of the chassis is improved and therefore the amplitude of resonance can be reduced and the resonance frequency can be changed. Since it is also possible to do so, the influence of mechanical resonance in the disk drive device can be suppressed to a small level.

[Brief description of drawings]

FIG. 1 is a perspective view of a chassis according to a first embodiment in an upside-down state.

FIG. 2 is an explanatory view of fixing a beam member to a chassis.

FIG. 3 is a perspective view of the chassis of the second embodiment in an upside-down state.

FIG. 4 is an explanatory diagram of an intersection of beam members.

FIG. 5 is a perspective view of a disk drive device.

FIG. 6 is a perspective view showing a conventional example of a chassis in an upside-down state.

FIG. 7 is an explanatory diagram of vibration of the chassis.

[Explanation of symbols]

 1 disk drive device 2 chassis 3 spindle motor 10 beam member

Claims (1)

[Claims] 1. A disk drive device in which a chassis for supporting the components of the disk drive mechanism is formed of metal such as aluminum, and the chassis is formed in a box shape having five or four surfaces closed by walls. In the disk drive device, the chassis structure is characterized in that a required number of beams are erected on a surface not covered by the wall portion of the chassis to improve rigidity.