JPH11260050A - Casing for housing magnetic disc - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to suppress the vibration by forming a hole bored at a resonance point region of the casing supporting a motor for driving a magnetic disc and a magnetic head which magnetically interacts with the magnetic disc rotating at a high speed to thereby mutually superpose vibration waves of the motor and the casing. SOLUTION: A casing body 1 is formed from a stainless steel metal layer 2 and ABS or other resin layer 3, having a hole 6 for a drive shaft 5 of a motor 4, vibration absorber 8, and a plurality of resonance-preventing holes 7 buried at center parts. The resonance-preventing holes 7 are formed to eliminate resonance position regions produced by rotating the motor 4 with the motor, magnetic disc, magnetic head, etc., assembled in the casing. As the result, the generated vibration of a sec. resonance region or internal stress based on this vibration is reduced more than that of the prim. resonance region. Thus it is possible to suppress the vibration by the reserve resonance of vibration waves of the motor and the casing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic disk housing. More specifically, the present invention relates to a magnetic disk-containing multi-layer housing for reducing the weight while securing sufficient rigidity of a magnetic disk rotating at a high speed and a housing body supporting the magnetic head, and an injection molding method thereof.

[0002]

2. Description of the Related Art A magnetic disk, a magnetic head interacting with the magnetism of the magnetic disk, a semiconductor substrate on which a semiconductor circuit is formed, and various input / output relations are provided on a housing body located at the heart of a computer. A circuit connection board or the like on which a circuit is formed to be relayed is supported. The relative positional relationship between the axis of rotation of the magnetic disk and the axis of oscillation of the magnetic head is maintained with high positional accuracy. When the housing body tilts during high-speed rotation of the magnetic disk, a strong force acts on the housing due to the gyro effect of the magnetic disk.

[0003] From the viewpoint of vibration with a small displacement width, a stress wave generated inside is also a main cause of vibration of the housing. For example, when a local area in the center of a stainless steel disc having a diameter of 1 cm and a thickness of 0.5 mm is instantaneously irradiated with a laser to supply calories that raise the temperature of the local area by several tens of degrees, the Young's modulus of the disk is increased. Although the value changes depending on the magnitude, expansion of about 1/100 micron occurs in the thickness direction for 1 microsecond. If such expansion occurs continuously in a local area, the distance between two points about 10 cm apart by the entire length of the 10 cm long casing being warped causes a relative displacement of 10 μm or more due to the warping. I will. The displacement due to the warpage exceeds the interval between adjacent information recording tracks on the magnetic disk.

Generally, such a housing to which various external forces act is used to maintain the relative positional relationship between the axis of rotation of the magnetic disk and the axis of oscillation of the magnetic head with high positional accuracy. , Given sufficient rigidity. Such a case requiring the required rigidity is manufactured by a molding method such as metal die casting so as to give a sufficient thickness. Such a manufacturing method hinders both weight reduction and cost reduction of the housing.

In order to make a computer portable, it is desired to reduce the weight of the housing. On the contrary, this weight reduction often hinders the suppression of generation of vibration. Conversely, high rigidity also often hinders suppression of vibration. It is desired to develop a housing that is reduced in cost and weight while suppressing the generation of vibration and ensuring rigidity.

[0006] As a thin-walled material that enhances vibration suppression and rigidity at the same time, a steel plate coated with a resin is known, and is widely used in the body of automobiles and the like. Such vibration-damping and rigid steel plates are designed with consideration given to suppressing vibration and securing strength with the peripheral edge as a boundary condition, but many holes are drilled and complicatedly bent to support many minute components. It was not developed to suppress minute stress deformation based on motor drive in a computer housing. On the other hand, the performance of the electromagnetic shield is also required.

[0007]

SUMMARY OF THE INVENTION The present invention has been made based on such a technical background, and achieves the following objects.

An object of the present invention is to provide a magnetic disk housing with high vibration damping.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic disk housing with high vibration damping performance and light weight.

Another object of the present invention is to provide a magnetic disk housing with high vibration damping and high rigidity.

It is still another object of the present invention to provide a lightweight magnetic disk housing with high vibration damping and high rigidity.

[0012]

According to the present invention, there is provided a housing for a built-in magnetic disk, comprising: a magnetic disk rotating at a high speed; a magnetic head magnetically interacting with the magnetic disk;
A motor for driving the magnetic disk is supported, and the housing body has one or more holes. This hole is drilled in the housing part that would otherwise form the resonance point region.

The housing body can be formed of a metal layer formed of a metal having higher rigidity and a resin layer having lower rigidity than the metal. As is well known, a two-layer structure made of different materials can increase rigidity and vibration suppression. The two-layer structure of the metal layer and the resin layer simultaneously has high electromagnetic shielding properties. The housing body may be formed of a liquid crystal polymer. In general, the liquid crystal polymer is composed of high molecular weight spindle-shaped unit particles arranged in a layered manner, and the alignment angle phase is sequentially changed from the lower layer to the upper layer to form a multilayer structure. Excellent shielding characteristics. The liquid crystal polymer selected is preferably formed thicker if it is less rigid than metal.

Preferably, a vibration absorber made of an elastic material is joined to the inner surface of the resonance preventing hole. Such a vibration absorber is less likely to generate a reflected wave by absorbing transverse stress vibration generated in the housing body, and can prevent secondary resonance. It is particularly preferable that the vibration absorber completely covers the resonance preventing hole, and it is particularly preferable that the vibration absorber be formed of an elastomer. Various types of elastomers are known and any of them can be used. Various engineering plastics can be used as a material of the resin layer forming the resin layer and the two layers. When engineering plastics is used as the material of the resin layer, it is preferable that it contains fibers. The fibers give the resin layer a Young's modulus that is significantly different from the Young's modulus of the metal body, and at the same time, can increase the rigidity of the multilayer structure and have high vibration absorption. As the fiber, a carbon fiber having a high affinity for the resin is preferable. The resin layer is used for engineering such as ABS and PC.
A mixture of plastics and about 20% by weight of carbon fibers is preferable for steel materials.

The hole for preventing resonance is formed by a single or a plurality of resonance holes generated by rotating a motor by incorporating a motor and a magnetic disk or a motor, a magnetic disk and a magnetic head into a housing. It can be formed by finding a point region and deleting that region. The deletion usually produces a new secondary resonance point region. This 2
The vibration in the secondary resonance point region or the internal stress based on the vibration is usually smaller than that in the primary resonance point region. By repeating such trial and error deletion, it is possible to substantially eliminate the occurrence of vibration of the housing body.

By forming such a hole, the housing, the motor and the like do not resonate, and no vibration occurs. In particular, the vibration absorber that fills the hole absorbs generated vibration energy and promotes reverse resonance.

[0017]

The vibration wave of the motor and the vibration wave of the housing are superimposed, that is, no vibration occurs due to reverse resonance. With the addition of the vibration damping structure and the vibration absorber, the reverse resonance can be further promoted, and the generation of micron-width vibration can be suppressed.

[0018]

Next, an embodiment of a magnetic disk housing according to the present invention will be described. FIG. 1 shows Embodiment 1 of a housing for a built-in magnetic disk according to the present invention. The housing body 1 is formed of two layers. The metal layer 2 as the first layer is formed by molding a stainless steel metal plate. The resin layer as the second layer is formed of a resin. It is preferable that the resin layer 3 is formed on the front side of the metal layer 2 in terms of appearance, touch, and the like. The resin layer 3 does not need to be formed on the front surface of the metal layer 2.

Various engineering plastics can be used for the resin layer 3. For example,
ABS, PC, etc. The metal layer 2 and the resin layer 3 can be integrated by a different material injection molding technique.

A hole 6 for inserting the drive shaft 5 of the motor 4 may be formed in the metal layer 2. This hole 5
Is not for forming a bearing. The metal layer 2 of the housing body 1 is provided with a plurality of holes at appropriate places. This hole is hereinafter referred to as a hole 7 for preventing resonance, distinguished from the hole 6 described above.
That.

A plug is preferably embedded in the resonance preventing hole 7. Such a stopper uses a vibration absorber 8. It is preferable that the vibration absorber 8 completely fills the resonance preventing hole 7 to completely block the inside and the outside of the housing body 1, but it is also possible to form a hole having a hole in the center. It is preferable that the vibration absorber 8 is tightly joined to and integrated with the hole surface of the resonance preventing hole 7. The vibration absorber 8 can be formed as an outer peripheral portion formed of an elastic material, and the central portion 9 can be embedded in the center of the outer peripheral portion.

In this case, for the central portion 9, a resin harder than the outer peripheral portion can be used. For example, the vibration absorber 8 is formed of an elastomer, and the central portion 9 is formed of engineering plastics. The elastomer can be arbitrarily selected from nylon elastomer, polyurethane-based elastomer, olefin-based elastomer, polyester-based elastomer, etc., having a JIS A hardness of 35 to 70 degrees, which is lower in hardness than engineering plastic.

The resonance preventing hole 7 is provided for two of the motor and the magnetic disk, or for the motor, the magnetic disk and the magnetic head.
It may be formed by finding a single or a plurality of resonance point regions generated by incorporating a person or the like into a housing and rotating a motor, and deleting the region. The deletion usually produces a new secondary resonance point region. This 2
The vibration in the secondary resonance point region or the internal stress based on the vibration is usually smaller than that in the primary resonance point region. By repeating such trial and error deletion, it is possible to substantially eliminate the occurrence of vibration of the housing body.

FIG. 2 shows a second embodiment of the disk-containing housing according to the present invention. The housing body 1 is a single layer. Although various engineering plastics can be used, it is preferable to use a liquid crystal polymer. As described above, the liquid crystal polymer has a vibration damping action and an electromagnetic shielding action.

The housing body 1 has a plurality of resonance preventing holes 7 formed at appropriate locations. A plug is preferably embedded in the resonance preventing hole 7. Such a stopper uses a vibration absorber 8. It is preferable that the vibration absorber 8 completely fills the resonance preventing hole 7 to completely shut off the inside and the outside of the housing body 1, but it is also possible to form a hole with a hole in the center. Is the same as in the first embodiment.

The housing body 1 is transmitted with vibrations generated by the motor 4 having a period with extremely high precision. If the resonance preventing hole 7 is not provided, a strong vibration is generated in the housing main body portion which should be located at the position of the resonance preventing hole 7, and a stress wave caused by the vibration propagates through the main body 1, and It covers the whole body.
The initial vibration reaching the resonance preventing hole 7 is reflected by the inner surface of the hole, and this reflected wave is newly added to the motor 4 (not shown in FIG. 2).
And disappears (ie, reverse resonance occurs).

When the vibration absorbing member 8 is provided in the resonance preventing hole 7, the transverse stress wave (in-plane stress) that reaches the inner peripheral surface of the resonance preventing hole 7 is absorbed by the vibration absorbing member 8. Due to the synergistic effect of the inverse resonance and the vibration damping, the stress disappears more reliably. If the housing body 1 is a liquid crystal polymer, the synergistic effect is more exhibited.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a multilayer housing for incorporating a magnetic disk according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the multilayer housing for incorporating a magnetic disk according to the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Housing main body 2 ... Metal layer 3 ... Resin layer 4 ... Motor 7 ... Resonance prevention hole 8 ... Vibration absorber

Claims (6)

[Claims] A magnetic disk rotating at a high speed; a magnetic head magnetically interacting with the magnetic disk; and a housing body for supporting a motor for driving the magnetic disk. A multi-layer housing for a built-in magnetic disk having a resonance prevention hole formed in a housing portion forming a resonance point region that would otherwise occur. 2. The housing body according to claim 1, wherein the housing main body is formed of a metal layer formed of a metal having higher rigidity, and a resin layer having lower rigidity of the metal. Magnetic disk housing. 3. The case according to claim 1, wherein the case body is formed of a liquid crystal polymer. 4. The magnetic disk housing according to claim 1, wherein a vibration absorber made of an elastic material is joined to an inner surface of the resonance preventing hole. 5. The housing for a magnetic disk according to claim 4, wherein the vibration absorber completely closes a resonance preventing hole. 6. The magnetic disk housing according to claim 4, wherein the vibration absorber is formed of an elastomer.