JPS5990269A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To center a center hub accurately by providing a spindle plate with four arms having weight, and moving pins at the inward end by inertial force and pressing and holding the center hole of the center hub. CONSTITUTION:Four centering arms 4 are supported freely rotatably on pins 5 at the reverse side of the spindle plate 2; and pins 6 on the inward end are fitted in notch parts 3 of the tip part of a spindle and weights 7 are fixed at the outside parts. When the spindle 1 rotates, the inertial force is generated by the weights 7 to rotate the arms 4, and the pins 6 move into the notch parts 3 as shown by an arrow B in a figure to be pressed and held on the internal circumferential surface of the center hole 14a of the center hub 14. Consequently, even if there are variances in the internal diameter of the center hole 14a and the diameter of the spindle, the hub is centered accurately.

Description

TECHNICAL FIELD The present invention relates to a magnetic disk device (2), and more particularly, to a magnetic disk device in which a magnetic disk having a center hub in the center is mounted.

Prior art A conventional device of this kind (2) has a spindle that has a diameter slightly smaller than the diameter of the center hole of the center hub, and the tip of this spindle is inserted into the center hole of the center hub, and the magnetic disk is inserted into the center hole of the center hub. I was performing centering.

When such a structure is adopted, there are the following drawbacks.

(1) Since the center hub is made of synthetic resin, the inner diameter of the center hole varies widely.In an attempt to solve this problem, the center hub is made of metal (which would be extremely expensive).

(2) If the centering accuracy is to be increased, the spindle must also be highly accurate (one finish), making it expensive.

Purpose The present invention was made in order to eliminate the following drawbacks of the conventional technology. It is an object of the present invention to provide a magnetic disk device having a C2 configuration so that it can be used in a C2 manner.

EXAMPLES Hereinafter, details of the present invention will be explained based on two embodiments shown in the drawings.

Figures 1 to 4 illustrate one embodiment of the present invention.
In the figure, the reference numeral 1 indicates a spindle, and a spindle plate 2 is fixed to the upper end of the spindle, which determines the reference position for mounting the cassette.

At a position c2 where the spindle plays 1 and 2 are attached to the upper end of the spindle 1, a plurality of notches 3 are formed on the circumferential surface at equal intervals in the circumferential direction and along the axial direction of the spindle 1. has been done.

As shown in FIG. 1, the cross-sectional shape of the notch 3 is formed so that the width in the rotational direction of the spindle plate 2 (in the direction of arrow A) becomes narrower.

The diameter of the upper middle hole of the spindle plate 2 is approximately equal to that of the tip of the spindle 1, and the inner circumferential edge of this center hole defines the outer circumferential edge of the notch 3.

On the other hand, on the back side of the spindle plate 2, a plurality of centering arms 4 are attached at equal intervals along the circumferential direction, that is, the number is equal to the number of the notches 3.

The centering arm 4 is formed into an elongated plate shape,
Its center part is rotatably supported by a pin 5, and a pin 6 made of an elastic material is provided upwardly protruding from its inner end, and this pin 6 is fitted into the notch 3. are doing.

Furthermore, a weight 7 is fixed to the outer end of the centering arm 4 for obtaining a large moment of inertia outside the spindle plate 2.

Also, as is clear from FIGS. 3 and 4, the back surface of the spindle plate 2≦2 has a through hole (massage person) 8 in the same shape.
a and 8b are formed on the same circumference at a predetermined interval.

A through hole 9 is formed in the middle of the centering arm 4 at positions corresponding to these through holes 8a, 8b+2, and a steel ball 10 is rotatably fitted into this through hole 9. ing.

Further, one end of a leaf spring 11 is fixed to the lower side of the centering arm 4 with a screw 12, and the free end of the leaf spring 11 faces the lower side of the through hole 9, and the steel ball 10 is placed on the side of the spindle plate 2. It's being pushed to.

In FIG. 3, the reference numeral 13 is a magnetic disk, and a center hub 14 is fixed at the center of the magnetic disk. This center hub 14 has a center hole 14a in its center into which the upper end of the spindle 1 is fitted, and a hub presser 15 (
It is held between the spindle plate 2 and the spindle plate 2.

Further, a drive pin 16 is protruded from a part of the upper surface of the spindle plate 2 and fits into a drive hole (not shown) formed on the center hub 14 side C2.

Next, the operation of the magnetic disk device according to the present invention configured as above will be explained.

First, a magnetic disk cassette is inserted from the cassette insertion slot of a device (not shown), and when it approaches the mounting reference position (2), the hub presser 15 descends and presses the center hub 14 against the spindle 1. At the same time as this setting is completed, it is moved to the mounting reference position (2). A motor (not shown) is rotated, and the spindle 1 rotates t.
Ru.

At this time, the drive pin 16 has not yet fitted into the drive hole formed on the lower surface of the center hub 14, but during the maximum rotation of one rotation, the drive pin 16 fits into the drive hole (-) and the center hub 14. Therefore, the magnetic disk 13 starts rotating.

In this state, the stop hole 14a of the center hub 14 is fitted into the upper end of the spindle 1, and the spindle ball 10 is fitted into the through hole 8 at the initial stage of rotation (2).

Eventually, as the spindle 1 rotates, the centering arm 4
A large inertial force begins to act on the weight 7, and the centering arm 4 rotates about the pin 5 from the position shown by the solid line in FIG. 3 to the position shown by the chain line, and one of the through holes 8a
The steel ball 10 moves from to the other through hole 8b, and the steel ball 1°, which is pressed by the leaf spring 11C2, fits into the through hole 8b and stops. This state is maintained until the spindle 1 stops rotating.

As the centering arm 4 rotates, the pin 6 moves within the notch 3, and as shown in FIG. 1 (moves from the wide part of the two notches 3 to the narrow part).

This direction of movement is indicated by arrow B. Due to this movement of the pin 6, the inner peripheral surface of the center hole 14a of the center hub 14 is pressed, and the center hub 1 is pressed by the plurality of pins.
4 accurate centering is performed.

Note that the angle θ at which the centering arm 4 rotates from one through hole 8a to the other through hole 8b needs to be an angle that can cover the maximum variation in the inner diameter of the center hole 14a of the center hub 14. be.

In addition, since the pin 6 is made of an elastic material, the pin 6 makes contact with the center hole 14a in a well-fitted state, and centering by the plurality of pins becomes more reliable.

On the other hand, when the spindle 1 stops rotating, the centering arm 4 rotates in the opposite direction to that described above due to the inertial force of the weight 7, and the steel ball 10 is inserted into the through hole 8a at the initial position and initialized. Return to state.

Note that the return movement of the centering arm 4 that occurs when the spindle 1 is stopped causes the pin 6 to move from the narrow side to the wide side of the notch 3, but at this time the contact between the center hole 14a and the pin 6 is released. , the center hub 14 is in a state where it can be easily removed from the spindle 1.

In this way, by simply providing a centering arm that utilizes the inertial force generated during the initial rotation and stop of the spindle, it is possible to accurately center the center hub and therefore the magnetic disk. hub 1
The processing accuracy of the center hole 14a of the spindle 1 and the spindle 1 is not a problem, and even if there is considerable variation in the inner diameter or diameter of the two, accurate centering can be performed.

In the above-mentioned embodiment, the number of centering arms 4 is shown as four, but if they are equally divided and arranged in the circumferential direction with respect to the spindle C, any number of centering arms 4 may be greater than or equal to three. Of course it's a good thing.

As is clear from the explanation in ``Effects'', according to the present invention, a centering arm is provided on the spindle that utilizes the inertia force generated when the spindle starts and stops rotating (1), and this centering arm is installed on the spindle side. The structure uses a bent pin to hold or release the center hole of the center hub, so even if there are variations in the inner diameter of the center hole of the center hub or variations in the diameter of the spindle, these dimensions can be maintained. Correct centering can be performed without being affected by errors at all.

[Brief explanation of drawings]

The drawings are for explaining one embodiment of the present invention, in which Fig. 1 is a plan view of the spindle, Fig. 2 is a longitudinal side view of the spindle, and Fig. 3 is a partially enlarged longitudinal side view of the spindle with a magnetic disk cassette installed. FIG. 4 is a bottom view of the centering arm. 1...Spindle 2...Spindle plate 3...Notch 4...Centering arm 6...Pin 7...Weights 8a, 8b...Through hole 10...Steel ball 11.
... Leaf spring 13 ... Magnetic disk 14 ...
・Center hub 14a...Center hole 15...Hub retainer 16...Drive pin Fig. 1 7 Fig. 3 Fig. 4-f Sekko Neho Masaru -〇
"February 271" Mr. Commissioner of the Patent Office 1 Display of Matters Showa 57 Volume Patent Department No. 198890 2,
Name of the invention: Magnetic de-resistance device 3, Relationship with the amended Nagisa patent applicant Name: Kya'n'en Eniko Co., Ltd. 4, Agent: Telephone: 03 (268) 2481 (Details) Column 6 of Detailed Description of the Invention of the Book, Contents of Amendment (1) "Spindle hole" in line 6 of page 6 of the specification is corrected to "steel ball."

Claims (1)

[Claims] A magnetic disk device in which a magnetic disk having a two-center hub is mounted on a spindle (2) A circumferential portion of the spindle (1) is provided with a plurality of arms rotatably supported; A magnetic disk device characterized in that a pin is provided on the end side to suppress and hold a center hole of a center hub, and an outer end side (two weights) is provided.