JPS6232388Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a magnetic disk device that is capable of recording and reproducing analog signals such as digital signals or audio signals even when the magnetic disk is housed in a case.

First, the magnetic disk device proposed by the present applicant will be described. FIG. 1 is an exploded perspective view thereof, and FIG. 2 is a top view and a bottom view thereof. In the figure, reference numeral 1 indicates a flexible magnetic disk that is based on a thin disc-shaped polymer film and has a magnetic layer uniformly formed on the lower surface, and reference numeral 2 indicates a ring-shaped magnetic disk in the circular opening at the center of the magnetic disk 1. A center plate is shown that is fixed via double-sided adhesive tape 3. The center plate 2 is formed by pressing a thin metal plate and has a flange 4, to which the magnetic disk 1 is adhered. In addition, a motor shaft insertion hole 5 having a substantially square shape is formed in the center of the center plate 2, and a position regulating pin insertion hole 6 is located at a position offset from this insertion hole 5 by a predetermined distance.
is formed.

A magnetic disk 1 integrally having the center plate 2 is housed in a case formed by combining an upper shell 7 and a lower shell 8. These shells 7 and 8 are, for example, injection molded products made of ABS resin containing an antistatic agent, and their outer peripheral portions are joined together by ultrasonic welding. A circular opening 9 is formed in the center of the lower shell 8, and the center plate 2 is placed in this opening 9 with some play. Reference numeral 10 indicates a circular arc-shaped rib divided into four parts extending along a concentric circle with respect to the opening 9, and a corresponding circular circular rib is also formed on the inner surface of the upper shell 7.

Further, a liner 1 made of a nonwoven fabric such as rayon is provided on the inner surface of each of the upper shell 7 and the lower shell 8.
1 and 12 are heat welded or ultrasonic welded.
The liners 11 and 12 are provided to automatically remove dust and prevent dropout when the magnetic disk 1 rotates, as well as to prevent abrasion of the magnetic disk 1 and generation of static electricity. When lining the lower shell 8 with the liner 12, a tongue piece 13 made of synthetic resin is interposed, and the liner 12
is ensured to be pressed against the magnetic surface of the magnetic disk 11.

Elongated holes 14, 15, 16, 17 of the same shape extending in the radial direction of the magnetic disk 1 are formed in the upper shell 7, lower shell 8, and liners 11, 12, and in the combined state, these elongated holes are superimposed. When the magnetic disk is attached to the main body of the device, the elongated hole 17 of the lower shell 8 and the liner 12
The magnetic head is connected to the magnetic disk 1 through the elongated hole 16 of the magnetic disk 1.
The head pad is inserted through the elongated hole 14 of the upper shell 7 and the elongated hole 15 of the liner 11.

Further, recesses 18 and 19 are formed on the outer surfaces of the upper shell 7 and the lower shell 8, including the portions where the elongated holes 14 and 17 are formed, and in these recesses 18 and 19, a long U-shaped cross section of aluminum or the like is formed. Holes 14-17
A shutter 20 having slits 21 and 22 having the same shape as the shutter 20 is slidably mounted. As shown in FIG. 2B, a guide groove 23 is provided along the side edge of the outer surface of the lower shell 8, and three protrusions 24 are formed on the shutter 20 to correspond to the guide groove 23 and protrude inwardly by pressing or the like. is provided, so that the shutter 20 is guided by the guide groove 23 and the second
As shown by solid lines in Figures A and B, the holes 16 and 17 for inserting the head and the elongated holes 14 and 15 for inserting the pad coincide with the slits 21 and 22, respectively.
As shown in the usage state in which the magnetic disk 1 is exposed to the outside, and as shown by the imaginary lines in the above figure, the elongated holes 14 to 17 are
A state in which the magnetic disk 1 is not in use, in which the magnetic disk 1 is covered by a shutter 20, can be selected. This shutter 20 protects the magnetic disk 1 and prevents dust from entering.

Furthermore, a lug 25 is provided at one corner of the lower shell 8 to prevent accidental erasing.
If 5 is broken off and removed, it cannot be erased. As shown in FIG. 2B, a pair of positioning holes 26 and 27 are provided at the two corners of the lower shell 8 for positioning the magnetic disk device when it is attached to the disk recorder body. ing. Positioning hole 2 of this lower shell 8
6 and 27 are not provided, and the other two corners are shown in the diagonally shaded position 2 in FIG. 2B.
8 and 29 serve as reference surfaces, and the magnetic disk device is supported at the reference position at the four corners. In this state, the magnetic disk 1 is rotated by the motor, and digital or analog signals are recorded or reproduced.

FIG. 3 shows the liner 12 against the lower shell 8.
As shown by diagonal lines in the same figure, the area along the peripheral edge of the liner 12 is welded, and the area corresponding to the tongue piece 13 indicated by 30 is not welded, and the magnetic disk 1 It is lifted up so that it is pressed against it. And long hole 1
6 and 17 are as shown in FIG. 4A, and as is clear from the figure, the long hole 1 of the liner 12 is
The opening width Ta of No. 6 is the same or slightly larger. If the positioning of the liner 12 with respect to the lower shell 8 is correct, there will be no problem.
As shown in FIG. 4B, if the positional relationship between the two deviates from the correct state, one peripheral edge of the elongated hole 17 indicated by 31 in the same figure will not be covered by the liner 12, and the other peripheral edge will not be covered. A portion of the liner 12 will protrude as shown at 32. This peripheral edge portion 31 comes into contact with the magnetic disk 1 when ultrasonic vibration is applied during the welding process of the upper and lower shells, damaging the magnetic disk 1 and causing dropout. Furthermore, the fact that part 32 of the liner 12 is visible from the outside poses a problem in terms of commercial value.

This invention solves the above-mentioned problems.

An embodiment in which this invention is applied to the above-mentioned magnetic disk device will be described with reference to FIG. In this example, a chamfer as shown at 33 is provided on the edge portion of the inner surface along the elongated hole 17 of the lower shell 8. In this case, the opening width Ta of the long hole 16 of the liner 12 is made larger than the opening width Tb of the long hole 17 of the lower shell 8, and at least the dimensional difference (Ta
-Tb) width chamfer 33 is provided. That is, if the width of the chamfer 33 is Tc, the relationship is selected as (Tc>Ta-Tb).

Moreover, FIG. 6 shows another embodiment of this invention.
In this example, a counterbore 34 is provided on the inner surface of the shell 8 along the long hole 17.
As in the previous embodiment, the elongated hole 16 of the liner 12
The opening width Ta of the elongated hole 17 of the lower shell 8 is
The width Tc of the counterbore 34 is set to be larger than Tb, and the width Tc of the counterbore 34 is selected to satisfy the relationship (Tc>Ta-Tb).

Although the above description refers to the relationship between the lower shell 8 and the liner 12, the inner surface of the upper shell 7 is chamfered or counterbored along the elongated hole 14, and the elongated hole 14 is provided with a chamfer or counterbore. opening width
Regarding Tb', the opening width Ta' of the elongated hole 15 of the liner 11, and the opening width Tc' of the chamfer or counterbore, (Tc'>
Ta′−Tb′).

As can be understood from the description of the above embodiments, according to this invention, when a liner is attached to a shell, even if the attachment position deviates from the normal position, if vibration is applied from the outside such as during welding, Furthermore, the edge of the head insertion window (elongated hole 17) does not come into contact with the magnetic disk 1, thereby preventing the magnetic disk 1 from being damaged. This window also prevents the white liner from being seen from the outside.
This has the advantage of not causing any problems regarding commercial value.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of an example of a magnetic disk device to which this invention can be applied, FIG. 2 is a top view and bottom view of an example of this magnetic disk device, and FIG. 3 is a partial plan view of this magnetic disk device. , FIG. 4 is a partial sectional view used to explain this magnetic disk device, and FIG.
The figure is a partial sectional view of one embodiment of this invention, and FIG. 6 is a partial sectional view of another embodiment of this invention. 1...Magnetic disk, 7...Upper shell, 8...
...Lower shell, 11, 12...Liner, 16,
17...Elongated hole for head insertion, 33...Chamfer,
34...Sat Guri.

Claims (1)

[Scope of utility model registration request] The upper shell and lower shell are combined,
A case in which a head insertion window and a drive shaft insertion window are formed, a magnetic disk housed in the case and rotationally driven by the drive shaft, and an upper shell in which the magnetic disk and the head insertion window are formed. or a liner made of nonwoven fabric or the like, which is interposed between the inner surface of at least one of the lower shells and has a window similar to the head insertion window formed thereon, and the inner surface of the edge of the head insertion window of the case. The opening width of the head insertion window of the liner is larger than the opening width of the head insertion window of the case, and the difference between the two opening widths is formed by the chamfer or counterbore. A magnetic disk device characterized by being formed to be smaller than the width of a counterbore.