JP2538036B2 - Magnetic disk device housing and vibration damping method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a housing of a large-capacity magnetic disk device which is an external storage device such as a large computer, and in particular, the device is vibrated by an earthquake or other disturbance. In some cases, it relates to a means for reducing vibration applied to the housing and the head disk assembly.

[Conventional technology]

Prior art of a large capacity magnetic disk device is shown in FIGS.
This will be described with reference to FIGS. The large-capacity magnetic disk device is designed to increase the storage capacity by combining several head disk assemblies 5 as shown in FIG. In this case, some head disk assemblies 5 and the power supply unit 2 that supplies current to the head disk assemblies 5 are housed in a casing which is a frame structure of the iron frame 4.

When the housing receives vibration or disturbance, the head disk assembly 5 causes relative displacement between the magnetic head and the magnetic disk to cause a read / write error, or in the worst case, , There is even a risk that the magnetic head and magnetic disk will crash. Therefore, in order to reduce the impact transmitted to the head disk assembly 5, the head disk assembly 5 is coupled to the housing via the vibration isolating rubber 8 as shown in FIGS. 4 and 5. On the other hand, the power supply unit 2 is directly connected to the housing as shown in FIG. 11 because some vibrations and shocks do not pose a problem.

That is, in the related art, as a vibration-proof measure for the head disk assembly, a vibration-proof rubber is provided on the head disk assembly as a shock absorber, but the vibration-proof of the housing itself has not been sufficiently taken into consideration.

Note that, as a conventional technique related to the present invention, for example,
There is one described in JP-A-62-239391.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technique is not always sufficient as a vibration-proof measure for the head disk assembly, and particularly when the housing resonates, Even so, a big vibration was transmitted. In addition, since the anti-vibration measures for the housing itself are not sufficient, there is a risk that the housing itself may be pressed or damaged.

Particularly, the head disk assembly housed in the upper stage was greatly affected.

In order to effectively utilize the space, it is effective to mount the head disk assembly in multiple stages in the vertical direction in order to increase the storage capacity with a small installation floor area, but guarantee the reliability of reading and writing information. In order to achieve this, a highly effective head disk assembly and vibration damping means for the housing are required. In particular, since the head disk assembly and power supply unit housed in the housing have a fairly large mass, the natural frequency of the housing in which they are mounted is approximately several Hz.
And low. For this reason, vibrations such as seismic waves that include spectra of various components are likely to resonate when input to the housing for a relatively long time. For this reason, it is necessary to provide more effective vibration damping means for the head disk assembly and the case than the prior art.

An object of the present invention is to suppress vibration (especially resonance) of a large-capacity magnetic disk device installed in a computer room or the like when the housing vibrates due to an external force such as an earthquake. To provide a means for reducing the vibrations transmitted to the mounted head disk assembly.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a housing of a magnetic disk device housing a head disk assembly and a power supply unit, an elastic member elastically acting in the direction of the natural vibration mode of the housing, and the elastic member. A mass supported by a member is provided, and the natural frequency of a vibration system including the mass and the elastic member is the same as the natural frequency of the housing.

That is, a mass equivalent to that of a power supply unit, a head disk assembly, or another specific weight is used, and the spring constant of the elastic member is determined so as to match the natural frequency of the housing in which these are mounted. It is a thing.

Further, in a vibration isolation method for a housing of a magnetic disk device that houses a head disk assembly and a power supply unit,
Using the head disk assembly or the power supply unit as a mass, an elastic member is interposed between the mass and the housing, and the spring constant of the elastic member is set to a natural vibration of a vibration system including the elastic member and the mass. This is an anti-vibration method in which the number is a spring constant having a value corresponding to the natural frequency of the housing in which the head disk assembly or the power supply unit is mounted.

[Action]

According to the above configuration, even if the housing of the magnetic disk device vibrates due to an external force such as an earthquake, the vibration system including the mass of the power supply unit, the head disk assembly, or the weight and the elastic member causes the vibration system due to the external force. Since the vibration of the housing is absorbed and the vibration of the housing is not transmitted to the head disk assembly, the magnetic head and the magnetic disk are displaced relative to each other to cause an information read / write error, or The magnetic disk never crashes. It is also possible to prevent the housing itself from being damaged by vibration.

〔Example〕

The first embodiment of the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 is a front view of a housing in which a power supply unit and a head disk assembly are mounted (a view from the magnet side of the head disk assembly), FIG. 2 is a side view thereof, and FIG. 3 is a perspective view of only the housing. It is a figure. 4 and 5 are views showing a head disk assembly.

The housing of the magnetic disk device is a frame structure having a rectangular parallelepiped shape in which an iron frame 4 as shown in FIG. 3 is assembled in the horizontal direction, the depth direction, and the vertical direction. The frame 4 is also incorporated in the side surface of the housing in order to increase the rigidity of the housing and for partitioning.

In the depth direction when viewed from the front of the housing (viewed from the direction A in FIG. 3), two pairs of power supply units are respectively moved and guided to the left and right two rows on the uppermost stage of the housing, and are supported later. And the rail 3a for fixing is running.

Below the uppermost stage for accommodating the power supply unit 2, similarly, a pair of rails 3b for supporting and fixing the eight head disk assemblies 5 in two rows in the left-right direction and four steps in the upper-lower direction in the case of being equipped. Is provided. As shown in FIGS. 1 and 2, two power supply units 2 and eight head disk assemblies 5 are mounted in this housing.
The mounted housing is fixed to the floor or the like of the computer room with bolts or the like. The housing has a natural frequency f that is determined from the boundary conditions of its mass and stiffness and grounding.

The mounting method of the power supply 2 and the head disk assembly 5 will be described in more detail below.

As shown in FIGS. 4 and 5, the head disk assembly 5 includes a spindle base 6 which covers a spindle portion (not shown) including a plurality of magnetic disks and a motor for driving the magnetic disks, a magnetic head, and A magnet base 7 that covers a carriage that supports and moves the rail, a rail that supports and guides the carriage, a rail housing that supports the carriage, a voice coil connected to the carriage, and a magnet (not shown above) that forms a voice coil and a magnetic circuit.
Etc.

As shown in FIGS. 4 and 5, the head disk assembly 5 has two portions of the spindle portion and two portions of the magnet portion supported and fixed to the case 9 via the vibration-proof rubber 8. The anti-vibration rubber 8 serves as a shock absorber that damps vibrations and impacts from the housing.
The case 9 for fixing the head disk assembly 5 is moved and guided along the rail 3b of the housing and then fixed at a predetermined position with a bolt or the like.

On the other hand, as shown in FIGS. 1 and 2, the power supply unit 2, which is the key to this embodiment, has an appropriate jig (not shown) for fixing the coil spring 1az at the n position on the bottom of the power supply unit.
Is attached, and the coil spring 1az is connected to this jig, and the other end of the coil spring 1az is fixed to a predetermined position where the power supply unit 2 of the housing should be housed, also via an appropriate jig. The coil spring 1az may be provided on the bottom of the power supply unit at at least four locations as long as the power supply unit 2 is stably supported and fixed.
Since each pair is supported by a pair of rails 3a, it is desirable to support and fix it symmetrically at even positions. Further, in order to save the trouble of mounting and assembling, it is preferable to provide the power supply unit 2 at the minimum necessary position for stably supporting and fixing the power supply unit 2.

Here, the principle of the dynamic damper is shown in FIGS.
This will be described with reference to the drawings. Consider an oscillating system including a spring having a mass m ₁ and a spring constant k ₁ as shown in FIG. This vibration system Has a natural frequency of. Similarly, the mass shown in Fig. 9
The vibration system consisting of a spring with m ₂ and spring constant k ₂ is Has a natural frequency of.

Next, consider a model as shown in FIG. 10 which is a combination of FIG. 8 and FIG. In Fig. 10, the vibration system consisting of the lower mass and the spring is the basic system, and the upper part is the auxiliary system. In FIG. 10, if an external force of frequency f acts on the mass m ₁ of the basic system, the masses m ₁ and m ₂ will vibrate in combination.

Here, when the external force frequency f is close to the natural frequency f ₁ of the basic system, resonance occurs. However, in FIG. 10, if the values of the mass m ₂ of the auxiliary system and the spring constant k ₂ are determined so that the natural frequency f ₂ of the auxiliary system matches the external force frequency f, the mass is calculated when there is no damping. Although only m ₂ vibrates and the external force acts, the amplitude of the mass m ₁ becomes 0, and no vibration occurs at all. This phenomenon is called reverse resonance.

That is, when the mass m ₁ and the spring k ₁ are vibrating by receiving an external force of the frequency f, a vibration system is newly formed in which the external force frequency f and its natural frequency are equal. If the mass m ₂ and the spring k ₂ are provided, the vibration of the original mass m ₁ can be completely suppressed. This newly added mass
A vibration system consisting of m ₂ and a spring constant k ₂ , that is, a vibration system of the auxiliary system in FIG. 10 is called a dynamic damper.

The first embodiment is a case of a magnetic disk device housing.
In order to configure the dynamic damper, an elastic member is inserted between at least one power supply unit included in the housing and a rail that supports and fixes the power supply unit. The value of this spring constant is such that the natural frequency of the vibration system when the power supply unit is considered to be the mass and the elastic member is considered to be the spring matches the natural frequency of the housing.

As another method for forming the dynamic damper in the housing of the magnetic disk device, as described later, a new weight and an elastic member are provided in the housing. The mass of this weight and the value of the spring constant of the elastic member are
The natural frequency of the vibration system including the weight and the elastic member is determined so as to match the natural frequency of the housing.

Further, the elastic member is provided in a plurality of directions in the housing of the magnetic disk device so as to act as a spring in the direction of the natural vibration mode of the housing mounted in the power supply unit, the head disk assembly or the like.

In the first embodiment, the power supply unit 2 and the rail 3a
The value of the spring constant of the coil spring 1az to be provided between is determined as follows. If the natural frequency of the housing in which the power supply unit 2 and the head disk assembly 5 are mounted is f (Hz) and the mass of the power supply unit is m, in order to configure the dynamic damper, the power supply unit 2 is That is, since it suffices to be supported by a spring having a spring constant of k = 4π ² f ² m (π is a circular constant), when the power supply unit 2 is supported by n coil springs, one coil spring Spring constant A coil spring having a value may be used.

The power supply unit 2 has wiring (not shown) connected to an electric circuit necessary for operating the magnetic disk device, but the wiring is not broken even if the power supply unit 2 vibrates. .

Next, the spring provided between the power supply unit 2 and the rail 3a may be not a coil spring but a leaf spring having a value similar to the above spring constant. This is the second embodiment.

Further, as shown in FIG. 6, a rubber 11 which can similarly be expected to have a spring effect may be provided between the power supply unit 2 and the rail 3a. For example, a rubber having a cross-sectional area A, a length l and a Young's modulus E is
It acts as a spring, and the spring constant in the lengthwise direction is EA
Evaluated with / l. Therefore, as described above, when the mass of the power supply unit 2 is m and the natural frequency of the mounted housing is f, when the power supply unit 2 is supported and fixed by n rubbers 11, the spring action is The length l, the cross-sectional area A, and the Young's modulus E in the direction of It suffices to use rubber that satisfies the relationship. This is the third embodiment.

Next, a fourth embodiment of the present invention will be shown with reference to FIG.
In this embodiment, a weight 10 having a certain mass and a coil spring 1b having a certain spring constant, which newly form a dynamic damper, are provided at the top of the housing. Between the mass M of the weight 10 provided and the spring constant K of the coil spring 1b, the natural frequency of the housing is f, That is, It will be good if there is a relationship. However, the weight 10 has n springs 1b
If you want to support It is necessary to satisfy the relationship of. There are four or more places to support the weight 10, and it is good to set the minimum number of places so that the weight 10 can be stably supported and the assembling work does not take time.

As a fifth embodiment, a leaf spring having the same spring constant may be used instead of the coil spring 1b.

Further, rubber may be used as the sixth embodiment. In this case, the length l in the direction in which the spring action is expected, the cross-sectional area A,
Between the Young's modulus E and the mass M of the weight, if the natural frequency of the housing is f and n pieces of rubber are used for supporting. It would be good if there was a relationship

Since it is more effective for the dynamic damper that the damping of the spring portion is smaller, it is preferable that the coil spring used in the first to sixth embodiments be a leaf spring and rubber having a minimum damping.

In the above description of the six embodiments, for easy understanding, the vertical (Z direction) vibration is taken as an example, but an elastic member such as a spring or rubber is used in the natural vibration mode with respect to the natural frequency of the mounted housing. May be provided in a plurality of directions so as to act as a spring. That is, for example,
In the first and second embodiments, in FIG. 1, assuming that the natural vibration mode for a certain natural frequency of the housing is bending vibration in the x direction, the spring 1ax is designed to act as a dynamic damper against this vibration. Is provided.

The value of the spring constant of this spring 1ax and the number of springs to be provided n
May be determined so that the relationship between these and the natural frequency f of the housing is as shown in the first embodiment of the present invention.
In addition, the natural vibration mode for another natural frequency is
If it is bending vibration in the y-direction in the figure, the spring 1ay is operated so as to act as a dynamic damper for this vibration mode.
Is provided. The excited natural vibration modes differ depending on how the housing is installed on the floor and how the earthquake shakes.In any case, the lower natural vibration modes of the housing are Because it is vibration, springs horizontally
If 1ax and 1ay are provided, they form a dynamic damper. For vertical vibration, spring 1a
z works.

Also in the third embodiment, a rubber having a cross-sectional area, a length and a Young's modulus which is a spring of a dynamic damper in the horizontal direction (x and y directions) with respect to the natural vibration mode in that direction may be used. . In addition, a rectangular parallelepiped rubber having a cross-sectional area and a length and a Young's modulus which are dynamic dampers for the natural frequency may be used in the direction of the natural vibration mode.

In the fourth to sixth embodiments as well, the vertical vibration has been described as an example, but elastic members such as springs and rubber may be provided in the horizontal direction (x and y directions).

Also in the first to third embodiments, the power supply unit may be housed in another stage instead of the uppermost stage of the housing,
If there is a head disk assembly that is not used for reading and writing information instead of the power supply unit, this may be used as a dummy for the mass.

According to these embodiments, since the housing is provided with the dynamic damper, even if the housing vibrates due to an earthquake or the like, the vibration of the housing is suppressed and the vibration transmitted to the head disk assembly is greatly reduced (the damping is extremely small). If a small elastic member is used, it can be suppressed to almost 0).

Therefore, even if a sudden earthquake occurs during operation of the magnetic disk device, it is possible to prevent information read / write errors, magnetic head and magnetic disk crashes, and pressure and damage to the housing. It is effective in improving sex.

In addition, since it is possible to reduce the vibration of the housing and head disk assembly, it is possible to further increase the height of the housing and equip a large number of head disk assemblies, thus reducing the floor area for installing the device. On the other hand, it is possible to increase the storage capacity.

The method of constructing the dynamic damper according to these embodiments is simple and inexpensive. In particular, according to the method of using the power supply unit as the dynamic damper, since it is only necessary to provide the elastic member at the supporting position of the power supply unit, it is not necessary to make a large design change from the conventional device, which is extremely economical.

Further, the method of constructing the dynamic damper by newly providing the weight and the elastic member without using the power supply unit requires some design changes, but it is also possible to suppress the vibration of the power supply unit.

〔The invention's effect〕

According to the present invention, when the housing of the magnetic disk device installed in a computer room or the like vibrates due to an earthquake or other external force, the vibration of the housing is suppressed and the head mounted in the housing is suppressed. Vibrations transmitted to the disc assembly can be reduced.

Therefore, the read / write error of the magnetic disk device due to the vibration can be prevented and the device can be prevented from being destroyed.

[Brief description of drawings]

1 and 2 are a front view and a side view of a first embodiment of the present invention, FIG. 3 is a perspective view of a housing, and FIGS. 4 and 5 are a perspective view and a side view of a head disk assembly. 6 and 7 are front views of the third and fourth embodiments of the present invention, respectively, and FIGS. 8 and 9 are explanatory views showing a vibration model of a one-degree-of-freedom system including a spring and a mass, and FIG. FIG. 11 is an explanatory view showing a vibration model of a two-degree-of-freedom system, and FIG. 11 is a front view showing a conventional housing in a mounted state. 1ax, 1ay, 1az, 1b …… Coil spring, 2 …… Power supply unit,
3a, 3b ... Rails, 4 ... Frame, 5 ... Head disk assembly, 6 ... Spindle base, 7 ... Magnet base, 8 ... Anti-vibration rubber, 9 ... Case, 10 ...
Weight, 11 ... rubber.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Takahashi 2880 Kozu, Odawara City, Kanagawa Prefecture Odawara Factory, Hitachi, Ltd. (56) References: 57-87301

Claims (9)

(57) [Claims] 1. A housing of a magnetic disk device housing a head disk assembly and a power supply unit, an elastic member elastically acting in a direction of a natural vibration mode of the housing, and a mass supported by the elastic member. And a natural frequency of a vibration system including the mass and the elastic member is the same as the natural frequency of the housing. 2. A housing of a magnetic disk device for accommodating a head disk assembly and a power supply unit, wherein at least one of the power supply units is supported by the housing by an elastic member, and the power supply unit and the elastic member are provided. 2. The case of a magnetic disk device, wherein the natural frequency of the vibration system consisting of is the same as the natural frequency of the case in which the head disk assembly and the power supply unit are mounted. 3. A housing of a magnetic disk device for accommodating a head disk assembly and a power supply unit, wherein at least one of the head disk assemblies is supported by the housing by an elastic member. A housing of a magnetic disk device, wherein a natural frequency of a vibration system including an elastic member matches a natural frequency of a housing in which a head disk assembly and a power supply unit are mounted. 4. The housing according to claim 2, wherein, in the elastic member, a natural frequency of a vibration system including the elastic member and the head disk assembly or a power supply unit is a natural frequency of the housing. A housing of a magnetic disk device, having a spring constant of a matching value. 5. The housing according to claim 2, 3 or 4,
A case of a magnetic disk device, wherein the elastic member elastically acts in a direction of a natural vibration mode of the case. 6. The housing according to claim 1, wherein the elastic member is a coil spring. 7. The housing according to claim 1, wherein the elastic member is a leaf spring. 8. The elastic member is elastic rubber.
The housing according to any one of 1 to 5. 9. A vibration isolating method for a housing of a magnetic disk device containing a head disk assembly and a power supply unit, wherein the head disk assembly or the power supply unit is used as a mass, and an elasticity is provided between the mass and the housing. With a member interposed, the spring constant of the elastic member is such that the natural frequency of the vibration system consisting of the elastic member and the mass matches the natural frequency of the housing in which the head disk assembly and the power supply unit are mounted. A method for isolating the enclosure of a magnetic disk device as a constant.