JPH0589629A - Structure for fixing discold recording medium - Google Patents

Abstract

PURPOSE:To provide a medium clamping structure in which media are clamped without deformation and smooth undeformed media are piled up. CONSTITUTION:Discoid recording media having central holes are alternately piled up with spacers 4 in between and the recording media are pressed and fixed in their thickness direction by using a clamping plate 5. A thin wall section is provided in the claw section 5' of the clamping plate 5 so that only the axial tension component of the pressing force generated by the clamping plate 5 can be uniformly applied to the circumferences of the recording media and the angle of the claw section 5' is constituted on the negative side (inside). In addition, the position of the contact point of the claw section 5' is deviated to the axial center side from the thickness center of the click section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc-shaped recording medium fixing structure such as a magnetic disk, and more particularly to an optimal clamp plate structure for clamping a medium without deforming it.

[0002]

2. Description of the Related Art A conventional disk-shaped recording medium, for example, a laminated structure of a magnetic disk is shown in FIGS. A conventional structure as shown in FIG. 7 is found in Japanese Patent Laid-Open No. 61-241525, and an example of the structure shown in FIG. 8 is found in Japanese Utility Model Laid-Open No. 62-3679.

In the prior art shown in FIG. 7, a buff 2 is fitted on a rotary shaft 1, and a plurality of magnetic disks 3 and a plurality of spacers 4 are alternately laminated on the outer periphery of the hub 2.

At the uppermost stage of the laminated body of the magnetic disk 3 and the spacer 4, the outer edge portion is axially bulged to form a claw portion,
A clamp plate 5 having a thin shell structure with elasticity is fixed to the hub 2 by a plurality of bolts 6 provided at equal intervals in the circumferential direction. FIG. 8 is an example of a vertical cross-sectional view of a conventional laminated structure using a flat clamp plate 5 having a claw portion that belongs to the axial direction as a clamper.

When the bolts 6 are fastened in the laminated structure shown in FIGS. 7 and 8, the clamp plate 5 and the claw portions 5'clamp the disk laminated bodies, respectively.

[0006]

Since a disk-shaped recording medium, for example, a magnetic disk has a thin plate structure, it has an initial deformation due to latent factors such as assembly accuracy and part accuracy when it is stacked and assembled on the stacking hub. .. Further, when the magnetic disk rotates, it is vibrated by the fluid force generated by the flow of fluid around the magnetic disk, causing flutter on the magnetic disk. There is a proposition between the magnetic disk and the recording / reading head to prevent a head crash during actual operation, and it is necessary to minimize the vibration force applied to the recording / reading head of the magnetic disk. For that purpose, as a basic technique, it is necessary to reduce the amount of initial deformation that occurs when the magnetic disks are stacked and fixed.

As a prior art, as a means for fixing a laminated body composed of a magnetic disk and a spacer to a laminating hub, FIG.
The method of tightening the clamp plate of the thin plate shell structure that has been deep-drawn by using the elastic deformation, and
A clamping method utilizing the spring characteristic of the flat plate shown in FIG. 8 has been widely used. The important point of the clamp is to fix the recording medium securely, evenly and evenly on the laminating hub.

However, both of the conventional clamping methods have a drawback that the disk warps even if the load is equalized. The reason is that when the clamp plate is tightened with the bolt 6, an axial force is generated by the claw portion 5'provided on the outer edge of the clamp plate, and at the same time, the claw portion 5'deforms outward in the radial direction.
This is due to the generation of a bending moment in the radial direction that tends to bend the disk.

FIG. 9 shows a modified state. Clamp plate 5
Is clamped with a bolt 6 to generate an axial force F _Z at the claw portion 5 ′ while flexing in the axial direction. At this time, at the same time, the claw portions 5'expand outward in the radial direction and generate a bending moment M in the radial direction on the disk 3, which causes the disk 3 to deform. In particular, the warpage is larger when the flat clamp plate is used as compared with the shell structure. Due to this warp, the vertical acceleration at the time of rotation of the medium is increased, which gives a disturbance to the head, resulting in a decrease in reliability.

An object of the present invention is to fix a disk-shaped recording medium including a magnetic disk mainly by a uniform axial force component,
It is to provide a high-precision structure of a disc-shaped recording medium.

[0011]

The above object can be achieved by forming a cylindrical claw portion for directly pressing a disk or a spacer on a clamp plate as follows.

That is, as described in claim 1, (1)
A thin portion is provided on the plate thickness of the claw portion. As shown in claim 2,
(2) The angle of the pressing portion is made negative. As described in claim 3, (3) the contact portion position of the claw portion is decentered from the center of the plate thickness of the claw portion and is configured on the negative side.

[0013]

According to the present invention, in the conventional thin shell structure clamp plate, it is an object to reduce the bending moment in the radial direction generated in the claw portion by the bolt fastening. As shown in the figure, the thin portion is provided on the claw portion.

Since the clamp plate has an open cross-section structure as shown in FIGS. 7 and 8, bending moments are generated at the claw portions 5'in the direction of warping the discs together with the load, so that the discs are not bent. It occurs subtly. Therefore, in order to prevent bending due to a load, a thin portion is provided on the claw portion 5'of the clamp plate to eliminate the outward bending moment and to provide a clamp structure that generates only a uniform axial force on the circumference. It is possible.

Next, the means of claim 2 will be described.

As a method of producing the same effect as the thin means, there is a method of slightly bending the pressing angle of the claw portion 5'from the pressing axis direction to the negative side (direction toward the inner diameter side). That is,
By bending to the inner diameter side, in addition to the axial force, a moment toward the inner diameter side is generated, which cancels out the outward moment generated when bolts are tightened, and it is possible to press with only the axial force component and prevent disk deformation. Is possible.

Next, the means of claim 3 will be described.

It is also effective to make the contact position of the pressing portion of the claw portion eccentric to the inner diameter side of the plate thickness without making it coincide with the center of the plate thickness of the claw portion. This is to make it possible to reduce the bending moment generated in the direction of the outer diameter side by shifting the contact point inward.

As described above, according to the present invention, a structure in which the clamp plate claw portion is provided with a thin portion, the claw portion is bent inward, and the contact portion of the claw portion is eccentric to the inner diameter side is used independently or in combination. The clamp plate mainly has a structure that presses the disk in the axial direction, reduces the disk bending, and effectively generates only the axial direction. Therefore, the disk laminated structure can clamp the disk medium more smoothly. be able to.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in FIGS.

In the embodiment shown in FIG. 1, the hub 2 on the outer periphery of the rotary shaft 1 is fitted. On the outer circumference of the hub 2, center holes of a magnetic disk 3 which is a disk-shaped recording medium and a spacer 4 are fitted, and a plurality of these are sequentially stacked to form a laminated body.

A flat clamp plate 5 is arranged at the uppermost stage of the laminated body of the magnetic disk 3 and the spacer 4. The clamp plate 5 is formed with a cylindrical claw portion 5'which is bent in the axial direction, and the edge of the claw portion 5'presses and fixes the laminated body in the axial direction to form a laminated structure. I am configuring.

FIG. 1 is a sectional view of a clamp body having a substantially flat plate 5, and FIG. 2 is a sectional view of a laminated body having the clamp plate 5 having a shell structure. With this structure, in the present invention, the bending corner portion (A portion) of the claw portion 5'is grooved to form a thin plate. FIG. 3 shows an enlarged portion of the portion A (corner portion) shown in FIGS. 1 and 2. In FIGS. 1, 2 and 3, the clamp plate 5 is fastened with a tightening bolt 6 for fastening the clamp plate 5 to the hub 2.
Is bent in the axial direction to generate a force in the axial direction to press the laminated body of the spacer 4 and the disk 3. The corner portion of the clamp plate 5 is provided with a cutout having a radius r and an eccentricity δ _r . Therefore, the thickness of the clamp plate 5 is reduced at the corners, and when a load is applied by the bolt 6, the claw portions 5'of the clamp plate generate a bending moment component directed inward in the radial direction. It is possible to cancel out the conventional moment component generated outward and to transmit only the axial force component necessary for stacking to the disc side.

In FIG. 4, the claw portion 5'is bent inward in the radial direction (negative side) by an angle θ so that a bending moment is similarly generated inward in the radial direction. This also makes it possible to cancel the bending moment on the outer side ((+) bending moment) in the radial direction by the clamping force and the (-) bending moment generated by bending to generate only the axial force.

In the embodiment shown in FIG. 6, the contact end of the claw portion 5'is machined with a radius R of the chamfering center position deviated from the conventional plate thickness center by δ to contact the disk. Is a structure in which is moved inward in the radial direction. As a result, the (+) bending moment component M can be reduced more than in the conventional case, and only the axial force component F _Z can be effectively acted to clamp the disc.

As described above, according to the present invention, it is possible to stack and fix the disks extremely smoothly without causing deformation of the magnetic disks, and it is possible to provide a highly reliable magnetic disk device.

[0027]

According to the present invention, a thin portion is formed in the shape of the claw plate claw portion, it is bent radially inward by an angle θ, and the contact point position is radially inward from the claw portion plate thickness center. By eccentricity, the bending moment generated from the claw portion of the clamp plate (which causes the warp of the disk) can be reduced, and the axial force can be generated on the disk circumference under uniform conditions. Therefore, it is possible to eliminate the deformation of the recording medium and provide a highly reliable laminated structure of the disc-shaped recording medium.

[Brief description of drawings]

FIG. 1 is a sectional view of a shaft system showing an embodiment of the present invention.

FIG. 2 is a sectional view of a shaft system showing an embodiment of the present invention.

FIG. 3 is a partial cross-sectional view showing an embodiment of the present invention.

FIG. 4 is a partial cross-sectional view showing an embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing an embodiment of the present invention.

FIG. 6 is an explanatory diagram of an effect of the present invention.

FIG. 7 is a vertical cross-sectional view showing another conventional technique.

FIG. 8 is a vertical cross-sectional view showing another conventional technique.

FIG. 9 is an explanatory view of problems in the conventional art.

[Explanation of symbols]

1 ... rotating shaft, 2 ... hub, 3 ... disk, 4 ... spacer,
5 ... Clamp plate, 5 '... Claw portion, 6 ... Tightening bolt.

Claims (1)

[Claims] 1. A disc-shaped recording medium having an inner diameter substantially the same as that of the outer periphery of a hub tightly attached to a rotating shaft and spacers are alternately laminated and screwed to an end surface of the hub. In the disc-shaped recording medium in which the disc-shaped recording medium and the spacer are fixed to the hub by the claw portions of the clamp plate, a thin-walled portion is formed on the entire circumference of the cylindrical claw portion extending in the axial direction of the clamp plate. A fixed structure for a disk-shaped recording medium, which is provided.