JPH0241819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flexible magnetic disk device, and more particularly to a flexible magnetic disk device having a rack portion on which a magnetic head is placed and fixed, and a magnetic head moving platform having a coefficient of linear expansion substantially the same as that of the flexible magnetic disk. The object of the present invention is to provide a flexible magnetic disk device that is integrally molded using a resin having the following properties.

In a conventional flexible magnetic disk device, a drive motor winds up a steel belt that is fixed to a part of a magnetic head moving table to move the magnetic head toward a desired recording track on a flexible magnetic disk. There was one that was configured to be moved to a different position. However, with this device, the deflection of the steel belt that occurs when the motor winds and unwinds the belt causes errors in the feeding of the magnetic head.Furthermore, during assembly, the flat steel belt must be wrapped around the motor shaft and pulled onto the magnetic head moving table. The disadvantage is that it is difficult to position the movable table because the movable table is locked in place.

Another conventional example is a device in which a feed screw made of stainless steel, for example, which is screwed into a half nut provided on the magnetic head moving table is rotated by a motor to move the magnetic head moving table.
In this device, since the mass of the feed screw is large, there are disadvantages such as a delay in stopping the moving table due to the effect of inertia due to rotation, and stopping at a position deviated from the specified stopping position, resulting in inaccurate and unstable stopping position. Ta.

Another conventional device has a structure in which a machined rack part is attached to a magnetic head moving table, and a pinion attached to a drive motor meshes with the rack to drive it and move the magnetic head. However, since the rack part is a separate part from the movable table, there are disadvantages in that processing costs are high and assembly is time-consuming.

Furthermore, in any of the conventional devices, the linear expansion coefficient of the magnetic head moving table is not equal to that of the magnetic disk, so if the magnetic disk and the magnetic head moving table expand or contract due to temperature changes, the magnetic head and There was a drawback that positional deviation occurred between tracks.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings.

1 and 2 are a plan view and a side view of a flexible magnetic disk device according to the present invention. In both figures,
The magnetic head moving table 1 has a rack part 1a on the side and is made of polyphenylene sulfide resin (hereinafter referred to as PPS).
It is integrally molded with resin), and the arm part 1
A magnetic head 2 is placed and fixed at the tip of b. Since this PPS resin has excellent affinity, the linear expansion coefficient can be changed by adjusting the blending ratio of carbon fiber, glass fiber, etc., and the linear expansion coefficient of flexible magnetic disks such as those made of polyester can be changed. It is made to be almost the same as. In addition, PPS resin has high hardness and excellent wear resistance, so it can be used for gears, and its low coefficient of friction reduces frictional resistance, and it has excellent sliding properties, so it can be used for bearings. It has excellent moldability and can mass-produce high-precision parts by injection molding, making it particularly suitable for use in precision equipment such as magnetic disk drives.

A pinion 3 meshes with the rack portion 1a and is mounted on the rotating shaft 4a of the stepping motor 4. Reference numeral 5 denotes a guide rail, and its both ends are pressed and fixed in the recesses of a support stand 7 on the chassis 6 by the elastic force of a plate spring 8 fixed on the support stand 7, and the sliding movement of the movable stand 1 is prevented. This is inserted into the portion 1c so that it can slide. Reference numeral 9 denotes a presser pad, which is fixed to the tip of the arm 10 facing the magnetic head 2. The arm 10 is mounted on a rotating shaft 11 on the moving table 1.
It is rotatably supported by the torsion spring 1.
It is energized in the direction of arrow A by the repulsive force of 2.
Therefore, the presser pad 9 brings the flexible magnetic disk 13 into contact with the magnetic head 2 by the elastic force of the torsion spring 12. 14 is a turntable on which the disc 13 is placed. Reference numeral 15 denotes a tartable drive motor, which is fixed to the lower side of the chassis 6.

As shown in FIG. 3, the moving platform 1 has a rack portion 1a.
A through hole 1d is bored on the opposite side. A stainless steel ball 16 and a ball 16 are provided in the through hole 1d.
A ball holder 17 that presses down the ball 16 and a coil spring 18 that presses the ball holder 17 downward are housed. Further, a spring stopper plate 19 is screwed above the through hole 1d, and the spring 18
This prevents the material from slipping out.

Disc 1 placed on turntable 14
When recording or reproducing 3, the rotation of the motor 4 causes the pinion 3 to drive the movable table 1 in the direction of arrow X, and the magnetic head 2 moves to a position facing a desired recording track. In addition, when moving the magnetic head 2, a moving base 1 made of PPS resin with a small coefficient of friction is used.
Since the sliding portion 1c slides on the guide rail 5 with low friction and the ball 16 rolls on the chassis 6, it moves smoothly in a horizontal state. Moreover, since the moving table 1 is small and lightweight, the load on the motor 4 is reduced and the moving table 1 can be moved quickly and stably. In addition, since the spring 18 that presses the ball 16 against the chassis 6 presses the spring stopper plate 19 upward, the movable table 1 is urged to rotate in the direction of arrow B with the guide rail 5 as the rotation center axis. The portion 1a is pressed against the pinion 3 to stabilize the meshing state between the rack portion 1a and the pinion 3.

When the magnetic head 2 reaches a position facing a desired recording track by moving the movable base 1, the rotation of the motor 4 and pinion 3 is stopped, and the movable base 1 is stopped by the meshing relationship between the rack portion 1a and the pinion 3. .
When stopped, the movable table 1 has reduced inertia due to its reduced weight, and accurately stops at a predetermined stop position. still,
Since PPS resin has high hardness and excellent wear resistance, the rack portion 1a has sufficient strength and will not be damaged by impact when stopped. Presser pad 9 is spring 12
When the disk 13 is brought into contact with the magnetic head 2 by the repulsive force, the magnetic head 2 slides onto the track on the disk 13 rotated by the turntable drive motor 15 to perform recording or reproduction. Furthermore, since the linear expansion coefficients of the moving platform and the magnetic disk are approximately the same, even if the disk expands due to a rise in temperature or contracts due to a drop in temperature, the magnetic disk remains fixed on the track on the disk and on the moving platform. No deviation occurs in the facing positional relationship with the magnetic head. In other words, the magnetic head accurately contacts the desired track regardless of temperature changes, resulting in stable recording/recording.
It is also possible to correspond to a high-density track disk in which playback is performed and the track spacing is narrow.

As described above, the flexible magnetic disk device according to the present invention includes a magnetic head moving platform to which a magnetic head for recording/reproducing data on/from a flexible magnetic disk is fixed and moves back and forth along the radial direction of the flexible magnetic disk. A rack part that meshes with the gears of the drive motor is provided, and these parts are integrally molded from polyphenylene sulfide resin blended to have approximately the same coefficient of linear expansion as the flexible magnetic disk, so they do not expand or contract due to temperature changes. This prevents misalignment of the opposing arrangement between the magnetic head and the track, and can also accommodate disks with high-density tracks.In addition, the number of parts is reduced by integrally molding the rack part, which was previously a separate part from the moving table. By streamlining the assembly process, it can be manufactured at low cost. Furthermore, parts can be mass-produced with high precision. Particularly, by integral molding, it can be made smaller and lighter. As a result, the magnetic head feed operation is quick and easy. It is more accurate and requires less driving torque, allowing the motor to be made smaller. Furthermore, it has high hardness and wear resistance, and the rack part has sufficient strength, reducing frictional resistance and making the movement of the magnetic head smoother. It has the following features.

[Brief explanation of the drawing]

1 and 2 are a plan view and a side view of an embodiment of a flexible magnetic disk device according to the present invention, and FIG.
The figure is a sectional view showing the main parts of the moving table. 1...Magnetic head moving table, 1a...Rack part,
1b...Arm part, 1c...Sliding part, 2...Magnetic head, 3...Pinion, 4...Stepping motor, 5...Guide rail, 9...Press pad, 1
0... Arm, 13... Flexible magnetic disk, 1
4... Turntable, 15... Turntable drive motor, 16... Ball, 17... Ball holder, 18... Coil spring.

Claims (1)

[Claims] 1. A magnetic head moving platform to which a magnetic head for recording/reproducing a flexible magnetic disk is fixed and moves back and forth along the radial direction of the flexible magnetic disk is provided with a rack portion that meshes with a gear of a drive motor, and these A flexible magnetic disk device, characterized in that it is integrally molded from a polyphenylene sulfide resin blended to have substantially the same coefficient of linear expansion as the flexible magnetic disk.