JPH0454597Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is suitable for application to, for example, a floppy disk cartridge, and relates to a disk cartridge in which a center core is provided in the center of the disk. .

[Summary of the idea]

In this invention, when the drive shaft is inserted into the shaft insertion hole of the center core, the drive shaft is elastically pressed against the pair of positioning parts provided in the shaft insertion hole by the elastic pressing part provided in the shaft insertion hole. In the disk cartridge configured to press against the drive shaft, the elastic pressing portion and the pair of positioning portions are each formed with an arcuate surface having a curvature approximately equal to the curvature of the outer circumferential circle of the drive shaft,
By bringing these arcuate surfaces into contact with the outer peripheral surface of the drive shaft, it is possible to position the center core with respect to the drive shaft with high precision, and even if the drive shaft is repeatedly inserted into the shaft insertion hole, the positioning accuracy will not deteriorate. I tried not to do that.

[Conventional technology]

First, a conventional example of a disk cartridge using a floppy disk will be explained with reference to FIG.

A disk-shaped center core 2 molded from synthetic resin is fixed to the center of a floppy disk (hereinafter simply referred to as disk) 1 made of a magnetic sheet. This center core 2
A substantially triangular shaft insertion hole 3 is provided in the center of the shaft. A pair of positioning portions 4 and 5 are formed around the shaft insertion hole 3 by its two sides. Further, around the shaft insertion hole 3, an elastic pressing portion 6 is formed which forms approximately the same angle with respect to the pair of positioning portions 4 and 5. Note that this elastic pressing part 6
is integrally formed with the center core 2 by forming a slit 7 along one side of the shaft insertion hole 3.

When the disk cartridge is installed in a recording/reproducing device (not shown), the shaft insertion hole 3 of the center core 2 is inserted into the drive shaft 9 of the device, and chucking is performed. At this time, the elastic pressing part 6 of the shaft insertion hole 3 bends against its elasticity, and the reaction force (elastic restoring force) of the elastic pressing part 6 causes the approximately central part 6a of the elastic pressing part 6 to position the drive shaft 9 in a pair of positions. It is pressed elastically against the parts 4 and 5. With this, the axial center of the drive shaft 9
The center core 2, that is, the rotation center _P2 of the disk ₁ is aligned with P1. The disk 1 is rotationally driven by the rotation of the drive shaft 9.

[Problem that the invention attempts to solve]

By the way, in the disk cartridge described above, since the drive shaft 9 is elastically pressed against the pair of positioning parts 4 and 5 by the elastic pressing part 6 at one location,
If the precision of the pair of positioning parts 4 and 5 is increased, the center core 2 can be accurately positioned with respect to the drive shaft 9.

However, in this structure, the elastic pressing part 6 and the pair of positioning parts 4 and 5 always come into contact with the outer peripheral surface of the drive shaft 9 at the same position. For this reason, when the drive shaft 9 is repeatedly inserted into the shaft insertion hole 3, a center core such as a metal material that does not cause wear may suffice, but the center core 2 molded from synthetic resin has elastic A considerable amount of wear occurs at the contact portion between the pressing portion 6 and the pair of positioning portions 4 and 5. As a result, when the disk cartridge is used for a long period of time, the positional deviation of the center core 2 with respect to the drive shaft 9 gradually becomes severe, and the disk 1
There was a problem in which the eccentricity error gradually increased.

Accordingly, the present invention is intended to enable highly accurate positioning of the center core with respect to the drive shaft, and to prevent the positioning accuracy from deteriorating even if the drive shaft is repeatedly inserted into the shaft insertion hole.

[Means for solving problems]

In the disk cartridge described above, the present invention provides a circular arc shape having a curvature approximately equal to the curvature of the outer circumferential circle of the drive shaft at the contact portion of the elastic pressing portion and the pair of positioning portions that contact the outer circumferential surface of the drive shaft. The center core is positioned with respect to the drive shaft by these arcuate surfaces.

[Effect]

According to the present invention, each arcuate surface of the elastic pressing part and the pair of positioning parts comes into surface contact with the outer peripheral surface of the drive shaft almost evenly, so that the center core can be positioned with high precision with respect to the drive shaft. .

Furthermore, because the surface contact is made by each arcuate surface having a curvature approximately equal to the curvature of the outer circumferential circle of the drive shaft, even if the drive shaft is repeatedly inserted into the shaft insertion hole, each arcuate surface is unlikely to wear out, and the positioning Accuracy never deteriorates.

〔Example〕

Hereinafter, an embodiment in which the present invention is applied to a floppy disk cartridge will be described with reference to FIGS. 1 to 4. Note that the same parts as those of the conventional example described in the [Prior Art] section are given the same reference numerals, and the explanation thereof will be omitted.

First, as shown in FIG. 2, a case 11 of a disk cartridge is formed of synthetic resin or the like into a substantially square shape, and the disk 1 is rotatably housed within this case 11. As shown in FIG. The center core 2 is fixed to the center of the disk 1.
are loosely fitted into a pair of circular core fitting holes 12 provided at the top and bottom of the case 11. Note that case 1
1 has a pair of head insertion holes 1 for inserting a magnetic head.
3 is provided.

Next, as shown in FIG. 1, a circular shaft insertion hole 15 is provided in the center of the center core 2. Around the shaft insertion hole 15, the central angle is approximately
Circular notches 16 are formed at positions divided into thirds by 120 degrees, and these three notches 16 allow an elastic pressing part 17 and a pair of positioning parts 18, 19 to be formed around the shaft insertion hole 15. is formed. Note that the elastic pressing portion 17 obtains its elasticity by forming the slit 20. and the drive shaft 9
Arcuate surfaces 21, 22, 23 are formed at the contact portions of the elastic pressing portion 17 and the pair of positioning portions 18, 19, which contact the outer circumferential surface of the are each configured to be approximately equal to the curvature of the outer circumferential circle of the drive shaft 9.

That is, in this embodiment, the circular shaft insertion hole 15 has a curvature approximately equal to the curvature of the outer circumferential circle of the drive shaft 9.
is provided in the center core 2, and by forming three notches 16 around the shaft insertion hole 15, an elastic pressing portion 17 and a pair of positioning portions 18,
Nineteen arcuate surfaces 21, 22, and 23 are formed. Note that the arcuate surface 21 of the elastic pressing portion 17
are both arcuate surfaces 2 of the pair of positioning parts 18 and 19.
It is formed so as to protrude slightly inward from the circular locus formed by 2 and 23.

According to the disk cartridge described above, when the shaft insertion hole 15 of the center core 2 is inserted into the drive shaft 9, the elastic pressing portion 17 of the shaft insertion hole 15 is bent against its elasticity, and the elastic pressing portion 17 is bent. Due to the reaction force (elastic restoring force), the approximately central portion 17a of the drive shaft 9
is elastically pressed against the pair of positioning parts 18 and 19. With this, the rotation center P ₂ of the center core ₂ , that is, the disk 1, with respect to the axis P 1 of the drive shaft 9.
become consistent.

By the way, at this time, each of the arcuate surfaces 21, 22, 2 of the elastic pressing part 17 and the pair of positioning parts 18, 19
3 makes surface contact with the outer circumferential surface of the drive shaft 9 almost equally from three directions, so that the center core 2
is positioned with extremely high precision. Moreover, due to the surface contact by the respective arcuate surfaces 21, 22, and 23 having a curvature approximately equal to the curvature of the outer circumferential circle of the drive shaft 9,
Even if the drive shaft 9 is repeatedly inserted into the shaft insertion hole 15, the respective arcuate surfaces 21, 22, and 23 are unlikely to wear, and the positioning accuracy will not deteriorate.

Next, FIGS. 3 and 4 show modified examples, in which the shapes of two of the three notches 16 formed around the shaft insertion hole 15 are changed. In these modified examples, a pair of positioning parts 1
8 and 19 are formed approximately 90° apart at the central angle of the shaft insertion hole 15. Further, in the modification shown in FIG. 4, two notches 16 extend around both sides of the slit 20, and the elastic pressing part 17 is formed longer than the other parts. As in these modified examples, the positions of the pair of positioning parts 18 and 19, the elastic force of the elastic pressing part 17, etc. can be changed in various ways.

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

The present invention is not limited to floppy disk cartridges, but can be applied to various disk cartridges using various disks.

[Effect of idea]

In the present invention, each arcuate surface having a curvature approximately equal to the curvature of the outer circumferential circle of the drive shaft is brought into contact with the outer circumferential surface of the drive shaft, so that each arcuate surface faces the outer circumference of the drive shaft almost equally. By making contact, the center core can be positioned with extremely high precision with respect to the drive shaft, and eccentric errors of the disk can be minimized.

Moreover, since it is a surface contact with each arcuate surface,
Positioning accuracy does not deteriorate even if the drive shaft is repeatedly inserted into the shaft insertion hole. Therefore, even if the disk cartridge is used for a long period of time, the eccentricity error of the disk will not increase, so it is possible to guarantee good initial recording and playback characteristics over a long period of time, and improve reliability. can be significantly improved.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment in which the present invention is applied to a floppy disk cartridge, in which Figure 1 is a plan view of the main parts, Figure 2 is a perspective view of the whole, and Figure 3 is a perspective view of the whole. and FIG. 4 are plan views of main parts in a modified example. FIG. 5 is a plan view of the main parts of a conventional floppy disk cartridge. In addition, in the symbols used in the drawings, 1...disk, 2...center core, 9...drive shaft, 15...
...Shaft insertion hole, 17...Elastic pressing part, 18, 19...
...Positioning portions, 21, 22, 23...are arcuate surfaces.

Claims (1)

[Scope of claim for utility model registration] A center core provided at the center of the disk, a shaft insertion hole provided in this center core,
It has an elastic pressing part and a pair of positioning parts provided around the shaft insertion hole, and when the drive shaft is inserted into the shaft insertion hole, the elastic pressing part moves the drive shaft between the pair of positioning parts. In the disk cartridge configured to elastically press against the positioning portion, the elastic pressing portion that contacts the outer circumferential surface of the drive shaft and the contact portion of the pair of positioning portions each have a curvature approximately equal to the outer circumferential circle of the drive shaft. 1. A disk cartridge characterized in that arcuate surfaces having equal curvature are formed, and the center core is positioned with respect to the drive shaft by these arcuate surfaces.