JP2000339804A - Disk centering holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage to the inner peripheral surface of a perforated disk. SOLUTION: By pressing the inner peripheral surface of a perforated disk 8, abutted on a tapered cone 7 formed in the upper part of a vertically moved piston body 6 and mounted on a turntable 2, a tip member 17 made of polyacetal is pressed into the tip of a clamping pin 11 for centering and holding the disk 8. Thus, the damaging of the inner peripheral surface of the disk 8, the tip of the clamping pin 11 being strongly pressed thereto, is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for mounting an information recording medium such as an optical disk or other perforated disk such as a disk-shaped work requiring high-precision processing on a disk receiver provided at the upper end of a spindle. The present invention relates to a device for placing and centering.

[0002]

2. Description of the Related Art An information recording medium such as an optical disk or a magnetic disk is dried in a manufacturing process, or when information is recorded on the manufactured recording medium, or formed into a disk-like work requiring high precision processing. For example, when processing graduations on a graduation disk of an encoder, a disk centering and holding device for mounting these perforated disks on a disk receiver provided at the upper end of the spindle and centering and holding the disk is provided. Used. Examples of this type of centering holding device include those disclosed in Japanese Utility Model Laid-Open Publication No. Sho 60-106214 and Japanese Utility Model Laid-Open Publication No. Hei 6-43849.

In each of these centering and holding devices, at least three clamp pins radially arranged are pressed radially outward against the inner periphery of a center hole of a disk placed in a disk receiver, and Is held in a centered state. As a means for pressing the clamp pin against the inner periphery of the center hole of the disc, a method is adopted in which a taper cone that is raised and lowered coaxially with the spindle axis is brought into contact with the base end side of the clamp pin, and as a means for releasing the clamp pin, A method is employed in which the clamp pin is biased toward the center by a spring.

[0004]

The clamp pin of the above-mentioned centering holding device is pressed very firmly against the inner peripheral surface of the disk so as to reliably hold the perforated disk even when the spindle is accelerated or decelerated. For this reason, the conventional clamp pin is formed of a highly rigid metal.

On the other hand, for a disk-shaped work such as a disk substrate such as an optical disk or a scale disk of an encoder, resins such as polycarbonate, polymethyl methacrylate, and epoxy resin are often used. Although these resins are relatively hard, they are much softer than metal clamp pins, so that there is a problem that the inner peripheral surface of the disc pressed by the tip of the clamp pins is easily damaged.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a disk centering and holding device which does not damage the inner peripheral surface of a perforated disk.

[0007]

In order to solve the above-mentioned problems, the present invention provides a disk receiver for mounting a perforated disk on the upper end of a spindle, and a center hole of the disk mounted on the disk receiver. Means for arranging at least three clamp pins abutting on the inner periphery with their tips directed radially outward of the spindle, and pressing each of these clamp pins radially outward of the spindle; And a means for urging the clamp pin back to the center of the disk. This configuration employs a softer configuration.

That is, by forming the tip portion of the clamp pin, which is in contact with the center hole of the disk, with the same hardness as the material of the disk or softer than the material of the disk, the inside of the disk with the hole when the clamp pin is pressed is formed. The peripheral surface was prevented from being scratched.

As means for pressing the clamp pin radially outward, a taper cone which is raised and lowered coaxially with a spindle shaft by a cylinder is projected onto the upper surface of the disk receiver, and this taper cone is brought into contact with the base end of the clamp pin. A contact method can be adopted.

[0010] The same hardness as the material of the disc,
Alternatively, by fixing a separate resin softer than that, or by coating the same resin, the rigidity of the clamp pin can be secured and the inner peripheral surface of the disc can be prevented from being damaged.

[0011] As the resin, polyacetal can be employed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 (a) and 1 (b), the disk centering and holding device includes a turntable 2 serving as a disk receiver on an upper end of a spindle 1.
However, the center axis of the bolt 3
The cylinder chamber 4 and an air passage 5 communicating with a lower part of the cylinder chamber 4 and supplied with compressed air from below are provided on the central axis of the turntable 2. A piston body 6 is slidably inserted into the cylinder chamber 4, and a tapered cone 7 projecting from the upper surface of the turntable 2 and having a diameter reduced downward is integrally formed at an upper portion of the piston body 6.

At the center of the upper surface of the turntable 2, a boss member 9 into which a perforated disk 8 is fitted is provided with a bolt 10
It is fixed at. The boss member 9 is formed in a shape in which a cylindrical cup is turned down, and three pin holes 12 into which a clamp pin 11 is fitted are provided radially at a center angle of 120 ° on a peripheral wall thereof. Further, an elastic body 13 for urging the piston body 6 having the tapered cone 7 downward is attached to the upper bottom surface.

As shown in FIG. 2, the clamp pin 11 includes a steel pin body 16 provided with a flange 15 near a base end 14 formed in a spherical shape, and a hemispherical tip member 17 made of polyacetal. The projection 18 provided on the tip member 17 is press-fitted into a hole 19 provided on the tip surface of the pin body 16, and the tip member 17 is fixed to the pin body 16. As shown in FIG. 1, each clamp pin 12 is urged toward the center of the turntable 2 by a coil spring 20 mounted between the flange 15 and the edge of the pin hole 12 of the boss member 9. The base end 14 is in contact with the tapered cone 7.

The taper cone 7 is urged downward by an elastic body 13 and lowered, whereby the diameter of the conical surface contacting the base end 14 of each clamp pin 11 increases, so that each clamp pin 11 To the outside of the turntable 2 in the radial direction. Therefore, by this pressing force, the polyacetal tip member 17 of each clamp pin 11 is pressed against the inner peripheral surface of the disk 8 on the turntable 2.

When the disk 8 is mounted or removed, compressed air is supplied from the air passage 5 to push the piston body 6 upward. Due to this pushing up, the diameter of the conical surface of the tapered cone 7 that abuts on the clamp pin 11 decreases, and each clamp pin 11 urged by the coil spring 20 retreats to the center side, and the disk 8 placed on the turntable 2 Is released from the inner peripheral surface.

FIG. 3 shows a modification of the clamp pin 11. FIG. 3A is a diagram in which a resin tip member 17a is bonded to the tip surface of a steel pin main body 16a, FIG.
(C) is obtained by screwing resin tip members 17b and 17c to steel pin bodies 16b and 16c, respectively.
In (b) and (c), the screw shaft and the screw hole are formed on the opposite member. FIG. 3D shows a steel pin body 16d.
Is formed with a resin coating film 17d at the tip end. The resin forming the tip members 17a, 17b, 17c and the coating film 17d may have a hardness equal to or less than that of the substrate of the disk 8, and a resin other than polyacetal may be employed.

In the above embodiment, the diameter of the tapered cone pressing the clamp pin is reduced downward.
JP-A-60-106214 and JP-A-6-4384.
It is also possible to reduce the diameter upward, as disclosed in Japanese Patent Application Publication No. 9-99. Also, four or more clamp pins may be radially arranged.

[0019]

As described above, according to the disk centering and holding apparatus of the present invention, the tip of the clamp pin which is in contact with the inner peripheral surface of the disk is made to have the same hardness as the material of the disk, or to the lower part. Since the clamp pin is formed soft, the rigidity of the clamp pin can be ensured, and the inner peripheral surface of the perforated disc can be prevented from being damaged when the clamp pin is pressed.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional front view showing an embodiment of a centering holding device, and FIG. 1B is a sectional view taken along line BB of a.

FIG. 2 is a partially cutaway front view showing the clamp pin of FIG. 1;

FIGS. 3A, 3B, 3C, and 3D are front views each showing a modified example of a clamp pin; FIGS.

[Explanation of symbols]

 Reference Signs List 1 spindle 2 turntable 3 bolt 4 cylinder chamber 5 air passage 6 piston body 7 taper cone 8 disk 9 boss member 10 bolt 11 clamp pin 12 pin hole 13 elastic body 14 base end 15 flange 16, 16a, 16b, 16c, 16d pin body 17, 17a, 17b, 17c Tip member 17d Film 18 Projection 19 Hole 20 Coil spring

Claims (5)

[Claims] 1. A disk receiver for mounting a perforated disk is provided at an upper end of a spindle, and at least three clamp pins abutting on an inner periphery of a center hole of the disk mounted on the disk receiver are provided at the tip thereof. Are arranged radially outward of the spindle, and means for pressing each of these clamp pins radially outward of the spindle, and means for biasing each of the clamp pins in the direction of returning to the center of the spindle are provided. In the centering holding device, a portion of the clamp pin which abuts on the inner periphery of the center hole of the disk is formed to have the same hardness as the material of the disk or to be softer than the material of the disk. . 2. A means for pressing the clamp pin radially outward causes a tapered cone, which is raised and lowered coaxially with a spindle shaft by a cylinder, to project onto an upper surface of the disk receiver, and the tapered cone is provided at a base end of the clamp pin. 2. The disk centering and holding device according to claim 1, wherein the disk centering and holding device is abutted. 3. The disk according to claim 1, wherein a resin of the same hardness as the material of the disc or a softer resin than the material of the disc is fixed to a portion of the clamp pin in contact with the inner periphery of the center hole of the disc. A centering holding device for a disk as described in the above. 4. The disk according to claim 1, wherein a portion of the clamp pin which is in contact with the inner periphery of the center hole of the disk is coated with a resin having the same hardness as the material of the disk or a softer resin. Centering and holding device. 5. The disk centering and holding device according to claim 3, wherein the resin is polyacetal.