JPH0664874B2 - Flotpie disk processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is most suitable for application to, for example, a micro-floppy disk using a magnetic sheet having a diameter of 3.5 inches, and in particular, a central circle of a metal. The present invention relates to a method for processing a floppy disc in which a sheet-shaped recording medium is fixed to the outer periphery of a plate (for magnetic chucking).

[Outline of Invention]

According to the present invention, a horizontal flange is integrally formed by press working on an upper portion of an outer periphery of a horizontal metal central disk through a vertical cylindrical portion, and a sheet-shaped recording medium is fixed to the flange. In a floppy disc such as a floppy disc, after stamping the central disk, stamping is applied to at least one surface of the flange (for example, the surface opposite to the surface on which the sheet-shaped recording medium is fixed). By additionally performing the correction, the flange can be easily corrected horizontally to eliminate surface wobbling of the sheet-shaped recording medium during rotational driving by the turntable of the floppy disc.

[Conventional technology]

Conventional micro-floppy disk example
No. 38) will be described with reference to FIGS. 4 and 5.

First, as shown in FIG. 4, this conventional micro-floppy disc 1 has a substantially square-shaped central hole in the central portion and the outer peripheral portion of a central circular plate 2 made of a circular flat plate of metal such as stainless steel. 3 and a substantially rectangular eccentric hole 4 are formed by pressing, and a horizontal flange 6 is integrally formed by pressing through a cylindrical portion 5 perpendicular to the upper part of the outer periphery of the central disk 2. A magnetic sheet 7 having a diameter of 3.5 inches, which is a sheet-shaped recording medium, is formed and fixed to the lower surface of the flange 6 by adhesion with an adhesive 8.

As shown by the chain line in FIG. 4, the micro floppy disc 1 is rotatably housed in a cartridge 12 composed of upper and lower halves 10 and 11, and a central disk 2 is placed in a lower half 11.
A circular rib 14 integrally formed on the lower surface of the upper half 10 in a state of being loosely fitted in the turntable insertion hole 13 provided in the.
It is positioned by. The micro floppy disc 1 is magnetized horizontally on the turntable 15 by the central disc 2, and the center pin 16 and the drive pin 19 of the turntable 15 are placed in the center hole 3 and the eccentric hole 4. Is inserted, and the magnetic sheet 7 is driven to rotate horizontally in the cartridge 12 by the turntable 15 via the central disk 2. A pair of upper and lower recording / reproducing heads 18 contacting the upper and lower recording surfaces of the magnetic sheet 7 are moved in the radial direction of the magnetic sheet 7 as the magnetic sheet 7 is horizontally rotated. Magnetic sheet 7
Upper and lower recording surfaces are selectively recorded and reproduced.

[Problems to be solved by the invention]

However, in this conventional example, it was difficult to obtain the levelness of the flange 6 horizontally pressed through the cylindrical portion 5 that is perpendicular to the upper portion of the outer periphery of the central disk 2.

That is, the flange 6 is pressed (folded) at a right angle to the vertical cylindrical portion 5, but the pressing is
This is performed in consideration of the spring back after the flange 6 is bent at a right angle to the cylindrical portion 5. And because of the spring back, it is difficult to obtain the accuracy of press working,
Generally, as shown by the solid line in FIG. 5, the flange 6 is often inclined downward from the horizontal reference plane. In rare cases, as shown by the chain line in FIG. Some were tilted upwards.

However, if the flange 6 is inclined downward or upward from the horizontal reference plane in this way, when the magnetic sheet 7 is driven to rotate horizontally by the turntable 13 via the central disk 2, The surface runout of the magnetic sheet 7 occurs as shown by the solid line and the chain line in the figure. As a result, problems such as tracking deviation and spacing loss occur when recording and reproducing the magnetic sheet 7 by the recording / reproducing head 18.
Compared to 1MB (for standard recording), 2MB (for high-density recording) Micro Floppy Disk 1 was more serious.

The present invention allows the flange of the central disc to be easily straightened horizontally.

[Means for solving problems]

The present invention, in the aforementioned Flotpies disk, after pressing the cylindrical portion and the flange to the central disk of the metal,
At least one surface side of the flange is stamped by a horizontal punch having a large number of small projections or small protrusions, and the flange is horizontally corrected.

[Work]

According to the present invention, permanent pressing is generated in the flange by performing stamping on at least one surface side of the flange with a punch having a large number of small protrusions or small protrusions after pressing the central disk. Thus, the flange can be easily straightened horizontally.

〔Example〕

An embodiment in which the present invention is applied to a micro floppy disc will be described below with reference to FIGS. 1A and 2B. The same structural parts as those of the conventional example shown in FIGS. 3 and 4 are designated by the same reference numerals and the description thereof is omitted.

As shown in FIGS. 1A and 1B, the present invention will be described later on the upper surface or both upper and lower surfaces of the flange 6 after pressing the vertical cylindrical portion 5 and the horizontal flange 6 on the upper part of the outer periphery of the central disk 2. The stamping process is additionally performed to correct the flange 6 into a horizontal shape parallel to the central disk 2. It should be noted that the adhesive surface portion of the magnetic sheet 7 adhered to the lower surface of the horizontally-corrected fung 6 with the adhesive 8 is naturally horizontal.

Therefore, as described above, the turntable 15 horizontally drives the magnetic sheet 7 through the center disk 2, and the upper and lower recording / reproducing heads 18 select the upper and lower recording surfaces of the magnetic sheet 7. When recording and reproducing, the surface of the magnetic sheet 7 is prevented from wobbling, and the magnetic sheet 7 can be horizontally and extremely stably rotated. As a result, problems such as tracking deviation and spacing loss do not occur during recording and playback, and the recording and playback accuracy can be significantly improved, especially for micro-floppies of 2 MB (for high-density recording). Great for discs.

Next, a stamping method of the flange 6 will be described with reference to FIGS. 2A and 2B.

FIG. 2A shows that the lower die 20 is provided with a horizontal center disk mounting surface 21, a vertical cylindrical outer peripheral receiving surface 22, a horizontal flange receiving surface 23, etc.
A taper surface 24 is formed on the inner peripheral side of the flange receiving surface 23. The upper die 25 is provided with a horizontal punch 26, a vertical cylindrical inner circumference guide 27, and the like, and the punch 26 is formed with a large number of small protrusions (or small protrusions) 28.

FIG. 2B shows a large number of small projections 29 formed on the horizontal flange receiving surface 23 of the lower mold 20, but with the exception of the small projections of the upper mold 25.
The positions of 28 and the small protrusions 29 of the lower mold 20 are horizontally different from each other, and the small protrusions 29 of the lower mold 20 are arranged between the small protrusions 28 of the upper mold 25. As the shapes of the small protrusions 28 and 29, it is possible to employ various shapes such as a square shape, a triangular shape, a circular shape in a plan view, and a trapezoidal shape or a conical shape in cross section. The small protrusions 28 and 29 have an outer diameter of 0.5 to 1 mm, for example.
The objects were arranged at intervals of 0.5 to 1 mm.

Then, as shown in FIGS. 2A and 2B, the pre-pressed central disk 2 is horizontally mounted on the central disk mounting surface 21 of the lower die 20, and the cylindrical portion 5 is attached to the outer circumference of the cylindrical portion. The upper die 25 is pressed down onto the lower die 20 (so-called stamping) with the flange 6 abutting on the flange receiving surface 23 while being fitted into the receiving surface 22.
To do. Then, the inner circumferential guide 27 of the cylindrical portion is inserted into the cylindrical portion 5, and the horizontal punch 26 is stamped on the entire upper surface of the flange 6. And in the case of FIG. 2A, the punch
A large number of small protrusions 28 of 26 are stamped on the upper surface side of the flange 6, and in the case of FIG. 2B, a large number of small protrusions 28 and 29 on the upper and lower sides of the punch 26 and the lower die 20 are stamped on both upper and lower sides of the flange 6. To be done. When stamping only on one side of the flange 6, that is, on the upper surface side as shown in FIG. 2A, the lower mold 20
By providing the taper surface 24 on the inner peripheral side of the flange receiving surface 23, the connecting end side of the flange 6 with respect to the cylindrical portion 5 is made to escape at the taper surface 23 portion, and a large number of The small protrusion 28 can be effectively stamped. Further, the driving depth of the small protrusions 28, 29 into the flange 6 is, for example, 1/3 to 1/2 of the plate thickness of the flange 6.

By the stamping process of the flange 6 as described above, a permanent strain is generated in the entire flange 6, and the flange 6 is easily straightened into a horizontal shape parallel to the central disc 2.

By the stamping process as described above, a large number of small recesses 31 and 32 are formed on the upper surface and the entire upper and lower surfaces of the flange 6 as shown in FIGS. 1A and 1B, respectively. The third A
The figure shows the recesses 31 and 32 when the small protrusions 28 and 29 are formed into a regular trapezoidal shape.
The shape (stamping shape) of
When stamping is applied to only one surface side of the flange 6 as shown in FIG. 1A, if the large number of small protrusions are formed in a mesh shape, for example, a shape in which a large number of small protrusions intersect with each other, the structure shown in FIG. A mesh-shaped concave portion (stamping shape) 33 as shown in FIG.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments and various effective modifications can be made based on the technical idea of the present invention.

Further, the present invention is not limited to the micro floppy disc, but can be applied to various floppy discs that are recorded and reproduced by various methods.

〔The invention's effect〕

According to the present invention, permanent pressing is generated in the flange by performing stamping on at least one surface side of the flange with a punch having a large number of small protrusions or small protrusions after pressing the central disk. Thus, the flange can be easily straightened horizontally. Since the flange can be corrected horizontally, when the sheet-shaped recording medium fixed to the flange is rotationally driven by the turntable through the central disk, the surface deviation of the sheet-shaped recording medium as in the conventional example is caused. The sheet-shaped recording medium can be horizontally and extremely stably rotated without causing any problems, and problems such as tracking deviation and spacing loss do not occur during recording and reproduction, and the accuracy of recording and reproduction is significantly improved. be able to.

[Brief description of drawings]

FIGS. 1A to 3B show an embodiment of the present invention, wherein FIGS. 1A and 1B are enlarged cross-sectional views of a main part, and FIGS. 2A and 2B illustrate stamping processing. Sectional views, FIGS. 3A and 3B are plan views showing stamping shapes. FIG. 4 is a sectional view of a conventional example, and FIG. 5 is a partially enlarged sectional view of FIG. In the reference numerals used in the drawings, 2 ... central disk 5 ... cylindrical portion 6 ... flange 7 ... magnetic sheet 20 ... lower mold 25 ... upper mold 26 ... punch 28 ... small protrusion 29 ... … It ’s 〃.

Claims (1)

[Claims] 1. A horizontal flange is integrally formed by pressing on the upper portion of the outer periphery of a horizontal metal central disk through a vertical cylindrical portion, and a sheet-shaped recording medium is fixed to the flange. In a floppy disc, after pressing the cylindrical portion and the flange on the central disk, stamping is applied to at least one surface side of the flange by a horizontal punch having a large number of small protrusions or small protrusions. And a flange is configured to be straightened horizontally so as to process the floppy disk.