JPH0480473B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording disk equipped with a recording medium used in a magnetic disk cartridge or the like.

[Conventional technology]

As shown in FIGS. 5 and 6, a conventional recording disk 1 has through holes 5a and 5b formed in a case 2 to expose a hub 3 and a recording medium 4, and a fitting hole formed in the hub 3. 6a and 6b are fitted into support means of a drive device (not shown), and a recording/reproducing head (not shown) is brought into contact with the recording medium 4 through the through hole 5b.

As an example of the structure of the hub 3, the inner circumference of an annular metal disk 7 is embedded in the outer circumference of the hub 3 made of synthetic resin. As shown in FIG. 7, a plurality of through holes 8 are formed in the circumferential direction of this metal disk 7, and a shallow connecting groove 10 is formed between each pair of adjacent through holes 8. A resin annular body 9 is provided. This annular body 9 is the through hole 5a of the case 2.
It comes into contact with a part of the circumferential side and regulates the position of the hub 3,
This restricts the movement of the recording medium 4 in the radial direction. The base end 9a of this annular body 9 is formed in the through hole 8 of the metal disk 7 as shown in FIG. The bridge portion 11 (see FIG. 8) is formed to connect a pair of adjacent proximal end portions 9a to each other. As mentioned above, forming the proximal end 9a of the annular body 9 in the through hole 8 and providing the bridge portion 11 connecting a pair of adjacent proximal ends 9a are done in accordance with the metal disc 7. Although this is intended to increase the bonding strength of the annular body 9, it is not without its drawbacks.

That is, since the connecting groove 10 of the metal disk 7 is formed by press working, the area around the connecting groove 10 is easily deformed into a undulating shape due to the aperture. Since the flexible recording medium 4 is adhesively fixed to the upper surface of the metal disk 7 as shown in FIG. 6, the metal disk 7 is deformed in the circumferential direction as described above and its flatness is reduced. If so, the influence will inevitably appear on the recording medium 4, and the recording medium 4 will also wave in response to the deformation of the metal disk 7. As a result, the contact between the recording medium 4 and the magnetic head (not shown) deteriorates.
This causes partial wear of the recording medium 4 and deterioration of magnetic properties.

Furthermore, since the cross-sectional shape of the connecting groove 10 is rectangular, if the depth of the connecting groove 10 is increased, the constricted portion 12 of the metal disk 7 may be cut due to shear stress. The depth of 10 cannot be made too deep. Therefore, when forming the bridge portion 11, the flow of the synthetic resin is poor and there is a problem in moldability, and since only a thin bridge portion 11 is formed, the bonding strength of the annular body 9 to the metal disk 7 is not sufficient.

[Problem that the invention seeks to solve]

The present invention eliminates the drawbacks of the prior art, and has a high bonding strength of the annular body to the metal disc.
To provide a recording disk with good productivity and no deformation of the recording medium.

[Means for solving problems]

In order to achieve this object, the present invention has a connecting groove located at the boundary between the metal disk and the annular body, whose cross-sectional shape is tapered, and its depth increases toward the bottom of the groove. be.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a main part of a magnetic disk cartridge according to an embodiment, FIG. 2 is an enlarged sectional view of part A in FIG. 1, and FIGS. 3 and 4 are other embodiments of the magnetic disk cartridge in FIG. 2. FIG.

In FIGS. 1 to 4, numerals 1 to 12 indicate the same parts as the conventional ones.

13 is a connecting groove according to an embodiment of the present invention, and this connecting groove 13 has a tapered cross-sectional shape and a groove bottom 14.
The depth increases as you go further.

The difference between this structure and the conventional one shown in FIG. 8 is that in the one shown in FIG.
0 has a rectangular cross-sectional shape, whereas the connecting groove 13 shown in FIG. The point is that it becomes deeper.

By tapering the connecting groove 13 in this way, a part of the connecting groove 13 can be deepened, which improves the flow of the synthetic resin into the connecting groove 13 during outsert molding, and the flow of the synthetic resin into the connecting groove 13 during outsert molding is improved. Since the thick portion of the bridge portion 11 is formed approximately at the center, the annular body 9 can be joined to the metal disk 7 reliably and firmly.

Further, by tapering the cross-sectional shape of the connecting groove 13, the length of the constricted portion 12 of the metal disk 7 becomes longer, the constricted portion 12 does not need to be cut during press working, and formability is improved.

3 and 4 show other embodiments of the connecting groove 13 shown in FIG. 2, and the difference from the connecting groove 13 in FIG. The cross-sectional shape was V-shaped and inverted triangular, but the third
In the figure, the cross-sectional shape of the connecting groove 13 is trapezoidal, and the fourth
In the figure, the groove is semicircular or U-shaped, and the depth increases toward the groove bottom 14, and the other explanations are the same as those in FIG.

〔Effect of the invention〕

As described above, since the present invention uses a metal disk having a through hole that does not require drawing, deformation of the recording medium due to deformation of the metal disk is eliminated, and the positional relationship between the recording medium and the head is corrected. Always constant and stable characteristics can be obtained.

In addition, since the cross-sectional shape of the connecting groove is tapered, a part of the connecting groove can be deepened to increase the bonding strength of the annular body to the metal disk, and the narrow part of the metal disk can be lengthened. It has various advantages over conventional products, such as better moldability and suitability for mass production.

[Brief explanation of drawings]

1 to 4 are for explaining the recording disk of the present invention. FIG. 1 is a partial sectional view of a magnetic disk cartridge using the recording disk, and FIG. 2 is a partial cross-sectional view of a magnetic disk cartridge using the recording disk. FIGS. 3 and 4 are detailed views for explaining other embodiments of FIG. 2, and FIGS. 5 to 8 are for explaining conventional recording disks. Figures 5 and 6
The figure shows a bottom view and a partially enlarged sectional view of a magnetic disk cartridge using the recording disk, and FIG. 7 is a plan view of a metal disk used in the recording disk.
FIG. 8 is a partially enlarged sectional view of the recording disk. 3... Hub, 4... Recording medium, 7... Metal disk, 8... Through hole, 9... Annular body, 11... Bridge portion, 13... Connection groove.

Claims (1)

[Claims] 1. A hub made of synthetic resin with an annular metal disc embedded in its outer periphery, a disc-shaped recording medium whose inner periphery is adhesively fixed onto the metal disc, and a hub made of synthetic resin that protrudes along the circumferential direction of the metal disc. A plurality of through holes are provided in the metal disc along the circumferential direction, and a connecting groove is provided between a pair of adjacent through holes, and the metal disc and the annular body are What is claimed is: 1. A recording disk in which a through hole and a connecting groove are joined by a bridge portion filled in the connecting groove, wherein the connecting groove has a tapered cross-sectional shape.