JPS63204580A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To reduce the transmissibility of vibration and to suppress the maximum value of displacement due to shock to an allowable limit or less by inserting a two-layer structure body consisting of an elastic member having a high spring constant and a high attenuation factor and an elastic material having a low spring constant and a high attenuation factor between a disk enclosure and a base. CONSTITUTION:Each two-layer structure body 10 is constituted by laminating the 1st and 2nd members 11, 12 and respective bodies 10 are distributed and inserted between the external bottom face of the disk enclosure 1 and the fitting face of the base 2. In the 1st member 11, the maximum displacement against shock is suppressed to an allowable limit or less by its high attenuation factor and the transmissivility of high frequency vibration can be reduced by its high spring constant. In the 2nd member 12, the transmissibility of especially low and medium frequency vibration is reduced by its low spring constant and high attenuation factor. Thereby, the transmissibility of low, medium and high frequency vibration can be reduced as a whole and the maximum displacement due to shock can be suppressed to the allowable limit or less.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a magnetic disk device that can reduce and alleviate the transmission of external vibrations and shocks to the main body of the device.

[Conventional technology]

Conventionally, anti-vibration rubber has been inserted between the disk enclosure of a magnetic disk device and the base to which it is attached. For example, the anti-vibration rubber has a diameter of 10 mm and a height of:
It is a cylindrical body with a diameter of about 9 mm, and a metal screw embedded in one end thereof protrudes from the end surface, and a screw hole is provided in the other end. Screw the metal screw of the anti-vibration rubber into the base side, and screw the small screw into the screw hole from the disk enclosure side to secure it.

[Problems to be solved by the invention]

The conventional technology as explained above has a simple structure,
Reduces external vibrations and shocks to some extent. There are benefits to being able to alleviate this. However, as a vibration-proof rubber, it naturally has one spring constant,
Although the spring constant, '$i damping coefficient, is selected based on theory and experience, the 0 frequency is limited to vibrations with a wide range of vibrations, and the damping coefficient is limited to one damping coefficient. It is impossible to reduce transmission; in other words, when emphasis is placed on one range of frequencies, other ranges of frequencies are somewhat neglected; ■ Emphasis on vibration isolation neglects shock mitigation. In other words, the maximum displacement due to impact exceeds the permissible limit, and there is a problem that it is extremely difficult to achieve both vibration isolation and damping. Note that the spring constant is a numerical value representing the springiness of rubber as an elastic material, and is the force required to give a unit displacement to the rubber. Intuitively, the larger the spring constant, the harder the rubber. In addition, the damping coefficient is a numerical value that represents the degree of damping force as an internal frictional force accompanying the deformation movement of rubber.In the case of rubber, the main element is viscous friction that is proportional to speed, and a constant It is a composite of elements such as friction (Coulomb friction) and an element proportional to the square of velocity. The purpose of this invention is to solve the problems of the conventional technology, to reduce the transmission rate of vibration when receiving external vibrations with a wide range of frequencies and shocks, and to reduce the displacement due to shocks. An object of the present invention is to provide a magnetic disk device that can suppress the maximum value to below an allowable limit.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a disk
A first member made of an elastic material having a high spring constant and a high damping coefficient, and a second member made of an elastic material having a low spring constant and a higher damping coefficient between the enclosure and the base to which the enclosure is attached. The structure is such that a two-layer structure made of laminated materials is inserted and attached. In one embodiment, the two-layer structure is a columnar body distributed between the outer bottom surface of the disk enclosure and the mounting surface of the base. In another embodiment, the 2N structure is
The enclosure is configured so that it can be inserted and inserted by bending the ridge line of the outer bottom surface of the enclosure as a fold line.

[For use]

Since the configuration is as explained above, the operation of the present invention is as follows. (1) Due to its high spring constant, the first member can suppress the maximum displacement due to impact to below the allowable limit, and its high damping coefficient can reduce the transmission rate of vibrations, especially at high frequencies. . (2) The second member can reduce the transmission rate of vibrations, especially at low and medium frequencies, due to its low spring constant and higher damping coefficient. (3) Therefore, as a whole, it is possible to reduce the transmission rate of low, medium, and high frequency vibrations, and at the same time, suppress the maximum displacement due to shocks to below the permissible limit. According to the embodiment, the columnar body mainly has a tensile and compressive spring constant in the axial direction, and mainly has a shearing spring constant in two directions perpendicular to each other and perpendicular to the axis. The spring constant ratio has directionality. According to another embodiment, three mutually perpendicular parts of the L-shape
Both directions are mainly tension and compression. Since it has a spring constant, there is little directionality in the ratio of tension, compression, and shear spring constants.

【Example】

An embodiment of the invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the main parts of this first embodiment, in which numeral 1 indicated by two-dot chain lines indicates a disk enclosure, and numeral 2 indicates a base to which this is attached. Reference numeral 10 denotes a two-layer structure formed in a cylindrical shape, which is inserted and adhered to the four corners between the disk enclosure l and the base 2. This 2N structure 10 is constructed by laminating a first member 11 and a second member 12. First member 11. The first member 11 is both made of rubber and has a spring action and a damping action due to internal friction. Note that this damping effect is mainly based on so-called viscous damping, which is based on a damping force proportional to the vibration speed. However, the first member 11 has a high spring constant and a high damping coefficient, and the second member 12 has a low spring constant and a higher damping coefficient than the first member 11.
It is made of materials that have different properties and functions. The first member 11 needs to have a somewhat large spring constant in order to suppress the maximum displacement of the disk enclosure 1 to below an allowable limit when subjected to an external impact. Furthermore, the transmission rate of external vibrations to the disk enclosure 1 is suppressed to 1 or less, and the effect of vibration isolation can be enhanced. This is because, according to the theory of spring vibration, on the one hand, this transmissibility increases in proportion to the spring constant, but on the other hand, it decreases in inverse proportion to the square of the frequency of the vibration. This is because vibration absorption occurs due to the high damping coefficient. Note that this vibration absorption is due to interactions between rubber molecules and between rubber molecules and fillers. Since the second member 12 has a small spring constant, the transmission rate of external vibrations to the disk enclosure 1 tends to be kept low, even at low and medium frequency vibrations, and in addition, the damping coefficient is even larger. Greater vibration absorption occurs, further supporting the trend. However, since the spring constant is small against impact, the maximum displacement of the second member 12 is large (unavoidable). When the first member 11 and the second member 12 are laminated in two layers, As a result of combining the vibration and impact characteristics of each member,
It is possible to reduce the transmissibility of vibrations over a wide range of frequencies, and at the same time to alleviate the effects of shocks, thereby suppressing the maximum displacement below the permissible limit. Looking at the above from an energy perspective, it is as follows. When vibration or shock is applied to the two-layer structure 10 from the outside,
The energy is once absorbed inside the two-layer structure 10 as it deforms. This energy is divided into elastic energy and dissipated energy. The former elastic energy is reversible; on the one hand, it is returned to the outside;
On the other hand, it is transmitted to disk enclosure 1. The latter dissipated energy is irreversible and is dissipated as heat by doing work against internal friction. The important issues for vibration isolation and buffering effects are: ■ The proportion of elastic energy that is transmitted to the disk enclosure 1 is small compared to that returned to the outside, ■ The proportion of dissipated energy to the total is large □ be. ■The ratio of 1. It is determined mainly by the spring constant of the second member 11.12, and the ratio of ■ is determined by the spring constant of the second member 11.12. Second member LL12
is determined mainly by the damping coefficient. By the way, No. 1. The diameter and thickness of the second member 11.12 are:
The spring constant and damping coefficient are appropriately designed depending on the envisaged environment. In FIG. 1, the two-layer structure 10 has all spring constants for tension, compression, and shear in the Z direction, and
Regarding direction, it mainly has a shear spring constant. Therefore, it can be said that the vibration isolation and buffering effects of this two-layer structure 10 have directionality, and the main direction thereof is the Z direction. A second embodiment will be described with reference to FIG. In this embodiment, the two-layer structure 20 is a short member with a cross-sectional shape. In FIG. 2, first member 21. The second member 22 also has an L-shaped cross section, and is made of materials similar to the first member 11 of the first embodiment. It is exactly the same as the second member 12. 23 is a mounting frame, and the two-layer structure 20 is fixed to the inside of both ends thereof. This position corresponds to both ends of two opposing sides of the disk enclosure 1. In this case, the spring constants are mainly tensile and compressive in the Z and X directions, and the spring constants are mainly shear in the Y direction. Therefore, the vibration isolation and buffering effects of this two-layer structure 20 have some directionality, and the main directions are Z,
This is the X direction. A third embodiment will be described with reference to FIG. In this embodiment, the two-layer structure 30 is a corner member having an L-shaped cross section. In FIG. 3, first member 31. The second member 32 is also a corner member with an L-shaped cross section, and is made of materials similar to the first member 11 of the first embodiment. It is exactly the same as the second member 12. Reference numeral 33 denotes a mounting frame formed by bending a plate-like member into a rectangular shape, and the two-layer structure 30 is fixed to the four corners of the mounting frame. This position corresponds to each corner of the disk enclosure 1. In this case, the spring constants are mainly tensile and compressive in the x, y, and z directions. Therefore, this two-layer structure 30
There is little directionality in the anti-vibration and buffering effects. A fourth embodiment will be described with reference to FIG. In this embodiment, the two-layer structure 40 is an elongated member with a cross-sectional shape. In FIG. 4, first member 41. The second member 42 is a rectangular closed elongated member with an L-shaped cross section, and is made of materials similar to the first member 11 of the first embodiment. It is exactly the same as the second member 12. Reference numeral 43 denotes a mounting frame formed by bending a plate-like member into a rectangular shape, and the two-layer structure 40 is fixed to the inner peripheral surface of the mounting frame. This position corresponds to the outer periphery of the bottom surface of the disk enclosure 1. In this case, the spring constants are mainly tensile and compressive in the X, Y, and Z directions. Therefore, this two-layer structure 30
The anti-vibration and buffering effects have little directionality, and at the same time, the anti-vibration and buffering functions are further improved than in the third embodiment.

【Effect of the invention】

As explained above, in the present invention, the first member has a high spring constant that can suppress the maximum displacement in response to an impact to below an allowable limit, and a high damping coefficient that allows the first member to reduce the transmission rate of vibrations, especially at high frequencies. Due to its low spring constant and even higher damping coefficient, the second member can reduce the transmission rate of vibrations, especially at low and medium frequencies;
It is possible to reduce the transmission rate of medium- and high-frequency vibrations, and at the same time to suppress the maximum displacement caused by shocks to below the permissible limit. Therefore, the present invention has the following superior effects compared to the conventional technology. (1) The transmission rate of external vibrations to the main body of the magnetic disk drive can be reduced, and the impact of impact can be reduced, that is, the maximum displacement due to impact can be suppressed to below the permissible limit. As a result, the operational reliability of the magnetic disk device is maintained,
Extend lifespan. (2) Since the means are relatively simple, the cost increase, including the work for attaching the structure, is small. (3) According to the embodiment, it is possible to give directionality to the tension, compression, and shear spring constant ratios, that is, to the vibration isolation and cushioning effects, or conversely, to reduce the directionality. Measures suitable for the environment can be taken. (4) According to another embodiment, since the elastic material used is rubber, ■ it is easy to obtain the desired spring constant and damping coefficient by adjusting the type and amount of filler, and ■ it is relatively easy to shape. The spring constant ratio in three directions can be selected appropriately, and the device can be easily and firmly bonded to metal surfaces, making the entire device simple.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts of the first embodiment of the present invention, Fig. 2 is a perspective view of the main parts of the second embodiment, and Fig. 3 is a perspective view of the main parts of the third embodiment. , FIG. 4 is a perspective view of the main parts of this fourth embodiment. Code explanation 1: Disk enclosure, 2: Base, 10.20
,30,40: Two-layer structure, 11.21,31,
41: First member, 12.22, 32, 42: Second member, 23, 33, 43: Mounting frame. -1￥12 eyes 2. %Chosho Tai Ko 3 Hi 4th Threshold

Claims (1)

[Claims] 1) A first member made of an elastic material having a high spring constant and a high damping coefficient, and a first member made of an elastic material having a low spring constant and a higher damping coefficient than the first member, between the disk enclosure and the base to which the disk enclosure is attached. A magnetic disk device characterized in that a two-layer structure formed by laminating a second material made of an elastic material having a coefficient of elasticity is inserted. 2) The device according to claim 1, characterized in that the two-layer structure is a columnar body distributed and inserted between the external bottom surface of the disk enclosure and the mounting surface of the base. magnetic disk device. 3) A magnetic disk drive according to claim 1, wherein the two-layer structure is an L-shaped structure that is inserted by being bent along the ridge line of the outer bottom surface of the disk enclosure. 4) A magnetic disk drive according to claim 3, wherein the L-shaped bodies are distributed and arranged along the ridgeline. 5) A magnetic disk drive according to claim 3, wherein the L-shaped bodies are arranged continuously along the ridgeline. 6) A magnetic disk device according to any one of claims 1 to 5, wherein the elastic material is rubber.