JPH0548277Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a centering device for perforated disks such as magnetic disks and optical disks.

[Conventional technology and its problems]

Generally, when writing or reading information to or from a magnetic disk or an optical disk, or when performing an inspection after writing, the disk is rotated at a high speed. In this case, if there is misalignment between the disk and the spindle that supports it and rotates it at high speed, the disk will rotate eccentrically, so it is necessary to center the disk and rotate it with high precision.

As the conventional technology of the disk centering device, the fourth
There is one shown in the figure. In this centering device, a turntable 22 is provided above a spindle 21 that rotates at high speed, and a centering tool 23 is inserted into a hole a of a perforated disk D placed on the turntable 22 to center the disk D. The centering tool 23 is fixed by tightening a bolt 25 screwed into a screw hole 24 of the spindle 21, and the upper surface of the disk D is pressed by a flange 26 provided on the upper part of the centering tool 23.

By the way, in the above-mentioned centering device, since there is a margin for fitting between the hole a of the disk D and the centering tool 23, the disk D is often eccentric, resulting in poor centering accuracy. There is an inconvenience.

In addition, since the centering tool 23 is fixed by tightening the bolt 25, it takes a lot of effort to attach and remove the disk D. In some cases, the centering tool 23 becomes a nuisance and automation is difficult.

[Purpose of invention]

Therefore, the object of this invention is to provide a centering device that can eliminate the above-mentioned disadvantages, can center a disk with high precision, and can easily automate disk mounting.

[Structure of the idea]

In order to achieve the above object, this invention provides a turntable having a concave part for attracting and adsorbing a disk at the upper part of a rotationally driven spindle, and a cylindrical part at the lower part of a ball holder fixed concentrically with the turntable. at least three or more pockets are formed at equal angles in the turntable, a ball is stored in each pocket so as to be movable in the radial direction, and the upper surface of the turntable is provided with a circular ball storage recess into which the lower part of the ball fits; A taper cone that moves the ball in the outer radial direction by contact with the ball is attached to a piston that is moved up and down by the supply of fluid to the cylinder and the elasticity of a spring in a cylinder provided coaxially with the cylindrical part. The configuration includes the following.

[Effect]

With the above configuration, by moving the piston, the plurality of balls are pushed by the tapered surface of the outer diameter of the taper cone, and therefore move outward. Therefore, by placing the perforated disk on the table and moving the balls outward by the movement of the piston, each ball comes into contact with the inner diameter surface of the disk, so the disk can be held from the inner diameter surface. Can be done. In this case, the balls that hold the disk are arranged at equal angles, and since the balls are moved by being pushed by the tapered surface of the outer diameter of the taper cone, the amount of movement is equal, and for this reason, the disk can be centered very precisely. You can put it out.

〔Example〕

Embodiments of this invention will be described below with reference to FIGS. 1 to 3.

As shown in the figure, a turntable 2 is provided on the top of a spindle 1 that rotates at high speed, and a ball holder 3 provided on the turntable 2 has a rod 5 screwed into a screw hole 4 of the spindle 1. It is supported concentrically with the spindle 1 by the rod head 5' and is prevented from moving upwards by the rod head 5'.

The outer diameter of the ball holder 3 is smaller than the inner diameter of the perforated disk D placed on the top surface of the turntable 2. This ball holder 3 has a cylindrical portion 6 at the bottom, and a plurality of pockets 7 are provided at the lower end of the cylindrical portion 6 at equal angles.

The number of the pockets 7 may be at least three. In the embodiment, three pockets 7 are provided.
The pockets 7 are spaced apart at 120° intervals. A ball 8 is housed in each pocket 7, and the outer diameter of the ball 8 is greater than the thickness of the cylindrical portion 6.

A shallow ball storage recess 9 for supporting the ball 8 is provided on the upper surface of the turntable 2;
The bottom surface of the ball storage recess 9 is a tapered surface 10 that slopes downward toward the inner diameter.

A ball holder 3 is placed on the bottom of the ball storage recess 9.
A taper cone 13 is provided on the upper part of a piston 12 which is movably incorporated into a cylinder 11 coaxially with the cylindrical portion 6 of the piston. The taper cone 13 is
It becomes possible to enter the inside of the ball 8 arranged in an annular shape, and when entering, the tapered surface 14 of the outer diameter
is designed to push ball 8 outward.

The spindle 1 is provided with a passage 15 communicating with the cylinder 11, and by supplying fluid into the cylinder 11 from the passage 15, the piston 1
2 rises.

Further, the piston 12 is pushed down by the elasticity of a spring 16 built into the ball holder 3.

A recess 17 for disk suction is provided on the upper surface of the turntable 2 around the ball storage recess 9, and the recess 17 communicates with a suction passage 18 formed in the spindle 1, and the suction passage 18 is used for suction. As a result, a suction force acts on the recess 17, so that the disc D placed on the turntable 2
can be adsorbed.

The centering device shown in the embodiment has the above-mentioned structure, and this centering device connects the passage 15 to the cylinder 1.
Fluid is supplied to the inside of the turntable 1, and as the piston 12 rises, the ball 8 moves outward to center the perforated disk D placed on the turntable 2.

Now, when disk D is placed on the upper surface of turntable 2 and fluid is supplied from passage 15 into cylinder 11 to raise piston 12, tapered cone 13 enters the inside of balls 8 arranged in an annular shape, and balls 8 are pushed by tapered surface 14 of tapered cone 13. As a result, balls 8 move outward and come into contact with the inner diameter surface of disk D, clamping disk D from the inside.

Here, since the plurality of balls 8 are pushed by the tapered surface 14 of the taper cone 13 and move outward,
Since the amount of movement of each ball 8 is equal and the balls 8 are arranged at equal angles, the perforated disk D held from the inside by the balls 8 is centered and aligned with the axis of the spindle 1. is maintained.

In this state, a suction force is applied to the recess 17 by suctioning the suction passage 18, so that the disk D is suction-supported and can be rotated together with the spindle 1 by rotation of the spindle 1.

In this rotating state, information is written to, read from, or inspected on the disk D. In this embodiment, the inspection head 19 is arranged below the disk D, and the inspection head 19 is moved in the radial direction of the disk D to perform the inspection.

When removing the disk D, the suction to the suction passage 18 is released, the supply of fluid to the passage 15 is cut off, and the piston 12 is lowered by the elasticity of the spring 16. The piston 12
As the ball 8 is lowered, the ball 8 moves inward along the tapered surface 10, so that the disc D is no longer clamped, and the disc D can be removed from the turntable 2 by being pulled up.

In the embodiment shown in FIG. 1, the outer diameter of the taper cone 13 is a tapered surface with a larger diameter at the lower part, but as shown in FIG. You can also use it as In this case, the piston 12 is lowered by the elasticity of the spring 16 to center the disk D, and the piston 12 is raised by supply of fluid to the cylinder 11 to release the disk D from being clamped.

〔effect〕

As described above, this idea is such that when the piston is moved in the axial direction, a plurality of balls arranged at equal angles are pushed by the taper cone and moved outward.
It comes into contact with the inside of the perforated disk placed on the turntable and clamps the disk from the inside.
At this time, the amount of movement of the multiple balls is equal, so
In addition to being able to center the disk with extremely high precision, the piston is protected by a ball holder fixed on the turntable, so the piston is not affected by external disturbances and can be placed on the turntable. It is possible to always center the perforated disk with high precision.

Furthermore, since the perforated disc is held from the inside by a plurality of balls that move outward, the perforated disc can be attached and removed from directly above the turntable, and the automation of the disc apparatus is easy.

Furthermore, by controlling the supply of fluid to the cylinder, it is possible to automate the centering work, and by controlling the fluid, it is possible to maintain the disk on the turntable in the centered state. Because the disk can be held in an adsorbed state by the suction force acting on the recess,
Even if an external force acts on the disk during rotation of the disk, the disk is maintained in a centered state, and the disk can be rotated with extremely high precision.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing one embodiment of the centering device according to this invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 shows another embodiment of the same. FIG. 4 is a longitudinal sectional front view showing a conventional centering device. 1...Spindle, 2...Turntable, 3
... Ball holder, 6 ... Cylindrical part, 7 ... Pocket, 8 ... Ball, 9 ... Ball storage recess, 10
... Tapered surface, 11 ... Cylinder, 12 ... Piston, 13 ... Taper cone.

Claims (1)

[Claims for Utility Model Registration] (1) A turntable having a concave portion for attracting and adsorbing a disk is provided at the upper part of a rotationally driven spindle, and at least three Two or more pockets are formed at equal angles, a ball is stored in each pocket so as to be movable in the radial direction, and the upper surface of the turntable is provided with a circular ball storage recess into which the lower part of the ball fits, and the turntable is connected to the cylindrical portion. A piston that is moved up and down by the supply of fluid to the cylinder and the elasticity of a spring is installed in a coaxial cylinder, and the piston moves the ball in the outer radial direction by contact with the ball. A centering device for perforated discs with a taper cone. (2) The centering device for a perforated disk according to claim 1, wherein the bottom surface of the ball storage recess is a tapered surface that slopes downward toward the inner diameter side.