JPS606944Y2 - magnetic disk device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a magnetic disk device in which a 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 of the magnetic disk device, and FIG. 2 is a top view and a bottom view of the magnetic disk device.

In the figure, 1 shows a flexible magnetic disk that is based on a thin disc-shaped polymer film and has a magnetic layer uniformly formed on the bottom surface, and 2 shows a ring-shaped disk in the circular opening in 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.

A substantially square motor shaft insertion hole 5 is formed in the center of the center plate 2, and a rectangular position regulating pin insertion hole 6 is formed at a position offset from the insertion hole 5 by a predetermined distance.

A magnetic disk 1 having this center plate 2 integrally
is housed in a case formed by combining an upper shelf and a lower shell 8.

These shelves, 8, contain e.g.
Both are injection molded S resin and their outer peripheries 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.

IOA to IOD indicate arcuate ribs divided into four parts extending along a concentric circle with respect to the opening 9, and arcuate ribs are also provided on the inner surface of the upper shelf at positions forming a circular shape as a whole together with the ribs of the lower shell 8. is formed.

Furthermore, liners 11 and 12 made of a nonwoven fabric such as rayon are thermally or ultrasonically welded to the inner surfaces of the upper shelf and the lower shell 8, respectively.

When the magnetic disk 1 rotates, the runners 11 and 12
It is provided to automatically remove dust and prevent dropout, as well as to prevent wear of the magnetic disk 1 and generation of static electricity.

When lining the lower shell 8 with a liner 12, a tongue piece 13 made of synthetic resin is interposed to ensure that the liner 12 is pressed against the magnetic surface of the magnetic disk 1.

Above-mentioned upper shelf, lower shell 8, liner 11.1
2 is formed with long notches 14, 15, 16, 17 of the same shape extending in the radial direction of the magnetic disk 1, and in the combined state,
These lengths are superimposed.

When the magnetic disk is installed in the entire device, the magnetic head comes into contact with the magnetic disk 1 through the long hole 17 of the lower shell 8 and the long hole 16 of the liner 12, and the long hole 14 of the upper shelf and the liner The head pad is inserted through the elongated hole 15 of 11.

Further, recesses 1B and 19 are formed on the outer surfaces of the upper shelf and lower shell 8, including the portions where the elongated holes 14 and 17 are formed, and elongated holes are formed in the recesses 18 and 19 with a U-shaped cross section made of aluminum or the like. Slit 21 having the same shape as 14-17.
A shutter 20 having 22 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 protruded inwardly by pressing or the like on the shutter 20 in correspondence with the guide groove 23. Therefore, the shutter 20 is guided by the guide groove 23, and the side surface of the shutter 20 is formed into the recesses 18 and 1, as shown by the solid line in FIGS. 2A and 2B.
9 is slid to a position where it abuts one side wall of the head, and the elongated holes 16 and 17 for inserting the head and the elongated holes 14 and 15 for inserting the pad are inserted.
and the open state where the slits 21 and 22 coincide with each other and the magnetic disk 1 is exposed to the outside, and the position where the side surface of the shutter 20 abuts the other side wall of the recess 18 and 19, as shown by the imaginary line in the above figure. A closed state in which the magnetic disk 1 is covered by the shutter 20 can be selected.

The shutter 20 protects the magnetic disk 1 and prevents dust from entering.

Furthermore, notches 30 are provided at corresponding positions on the sides of the upper shelf and the lower shell 8, and the notches 30 are opened or closed by sliding of the shutter 20.

The cutout 30 is opened only when the shutter 20 is open, and is closed in other states.

This notch 30 is for detecting the shutter position so that when a magnetic disk device is installed in a disk recorder, the magnetic disk device can be installed only when the shutter 20 is in an open state.

Furthermore, a lug 25 for preventing accidental erasing is provided at a part of one corner of the lower shell 8, and if the lug 25 is broken off and removed, erasing cannot be performed.

As shown in FIG. 2B, a pair of positioning holes 26 and 27 are provided at two corners of the lower shell 8 for positioning the magnetic disk device when it is installed in the main body of the disk recorder. It is provided.

The positions 28 and 29 indicated by diagonal lines in FIG. 2B in the other two corners where the positioning holes 26 and 27 of the lower shell 8 are not provided serve as reference planes, and the positions 28 and 29 shown in the diagram in FIG. , the magnetic disk drive is supported at a reference position.

In this state, the magnetic disk 1 is rotated by the motor, and digital or analog signals are recorded or reproduced.

The above-described magnetic disk device is required to have the lower shell 8 always curved outward, as shown in FIG. 3A.

In this case, the upper shelf will warp inward, but when it is loaded into the disc recorder main body, some of the four lower corners will be bent over the pins 3 as shown by the two-dot chain line in FIG. 3B. It is supported at a standard height by the holder, and a portion of the four upper corners are pressed down by a holding pin 32 provided in the disc loading section of the main body.
Furthermore, since the tip of the drive shaft 34 that is erected from the reel stand 33 is regulated to have a predetermined height, the warpage of the upper shelf is corrected and no problem occurs.

As the warpage of the upper shelf is corrected, the warpage of the lower shell 8 is also corrected.

However, as is clear from FIG. 3C, the lower shell 8
If the disk is warped inward, the warp will not be corrected even if the magnetic disk device is mounted in the disk recorder main body, and the flange of the center plate 2 will come into contact with the periphery of the opening 9 of the lower shell 8. This results in an increase in load torque and, in extreme cases, a failure where the motor stops rotating.

In FIG. 3, for the sake of simplicity, liners and the like incorporated into the shell other than the magnetic disk 1 and center plate 2 are not shown.

Therefore, these shells are molded so that the upper shelf warps inward and the lower shell 8 warps outward, but various manufacturing steps such as welding the liner, welding the upper and lower shells, and attaching the shutter are performed. Over time, the warping condition changes, and there is a problem in that the lower shell 8 of the assembled magnetic disk device may warp inward.

As mentioned above, the object of this invention is to provide a magnetic disk device that can reliably prevent the lower shell from warping inward.

An embodiment in which this invention is applied to the magnetic disk drive shown in FIGS. 1 and 2 will be described below.

As shown in FIGS. 1 and 4, the above-described magnetic disk device has thick ring-shaped posts 35 provided at four corners of the upper shelf, and four thick ring-shaped posts 35 on the lower shell 8. A thin boss 36 is provided at a part of the corner.

Conventionally, when the upper and lower shelves 8 are combined, the thin boss 36 is fitted into the hollow part of the boss 35 with some looseness to position the shelves when the shelves are combined.

In one embodiment of this invention, as shown in FIG. 4A, the maximum dimension D□ between the hollow portions of the two bosses 35 on the upper shelf
and the maximum dimension D2 between the outer peripheries of the two bosses 36 of the lower shell 8, the relationship is selected to be (Di<D2).

This dimensional relationship is made to hold true both in the front-back direction and in the left-right direction of the upper shelf and the lower shell 8.

Therefore, when one boss 36 is fitted into the hollow part of the corresponding boss 35 in order to combine the upper shelf and the lower shell 8, the lower shell 8 is subjected to an inward force directed toward the center. acts, the lower shell 8 bulges outward, and the opposite force acts on the upper shelf, so when both shells are combined, as shown in Figure 4B, the upper shelf warps inward and the lower shell 8 bulges outward. The side shells 8 will warp outward.

FIG. 5 shows an enlarged view of only a part of the corner of the upper shelf, and the boss 36 of the lower shell 8 fits into the hollow part of the ring-shaped boss 35 formed in a part of each corner as shown by diagonal lines. I will do it.

In this case, by selecting the same dimensional difference (D2 Di) for each of the front and rear and left and right sides of the shell, the bosses 35 and 36 will abut at two diagonal locations on the shell, and will be uniform in each of the front and rear and left and right directions. A force will be exerted.

Therefore, as shown in FIG. 6, the inward curvature of the upper shelf and the outward curvature of the lower shell 8 are the same when viewed from the front, rear, left, and right directions.

The amount of warpage is selected such that, for example, the end of the shell differs from its unwarped position by about 0.3 to 0.5 degrees.

As can be understood from the description of the above-mentioned embodiment, according to this invention, the upper and lower shells are each provided with a fitting portion, and the sizes of the fitting portions are made different between the upper and lower shells, so that the lower shell Since the shell is curved outward, it is possible to prevent an increase in the load torque during rotation or a failure that would cause the magnetic disk to stop rotating.

FIG. 7 shows another embodiment of this invention, and like FIG. 5, only a part of the inner corner of the upper shelf is shown on an enlarged scale.

In this example, the two bosses 35 on the left and right sides of the upper shelf
The maximum dimension D2 between the outer circumferences of the two bosses 36A and 36B (or 36C and 36D) in the left and right direction of the lower shell 8 is slightly larger than the maximum dimension D□ between the hollow parts of A and 35B (or 35C and 35D). Therefore, in the left and right direction, the same dimensional relationship as in the above-mentioned embodiment is selected so that these bosses can be fitted in each other without bending the lower shell 8, only in the front-back direction.

Therefore, in another embodiment of this invention, as shown in FIG. 8, the shell does not warp in the left-right direction, but only in the front-back direction.

In other embodiments of this invention, the lower shell can be regulated to warp outward in the same way as the above-mentioned embodiment.
Also, the direction in which the shutter 20 slides (left and right direction)
In this case, since the shell is not warped, the shutter 20 can be slid smoothly.

[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 cross section used to explain this magnetic disk device. Figure 4 is a sectional view of a shell in an embodiment of this invention, Figure 5 is an enlarged plan view of a corner part of the upper shell of an embodiment of this invention, and Figure 6 is an embodiment of this invention. 7 is an enlarged plan view of a corner part of the upper shell of another embodiment of this invention, and FIG. 8 is another embodiment of this invention. FIG. 2 is a top view, a front view, a rear view, and a side view showing the external shape of the vehicle. DESCRIPTION OF SYMBOLS 1... Magnetic disk, 2... Center plate, 7... Upper shell, Death... Lower shell, 20... Shutter, 34・・・・・・
...Drive shaft, 35.35A-35D...Ring-shaped boss, 36.36A-36D...Boss.

Claims (1)

[Scope of utility model registration request] A case formed by combining an upper shell and a lower shell and forming a head insertion window, and a magnetic disk rotatably housed in the case and rotated by a drive shaft inserted from the side of the lower shell. A magnetic disk drive comprising: a first fitting part protruding from the inner surface of the upper shell; and a second fitting part fitted inside the first fitting part protruding from the inner surface of the lower shell. The size of the area between the parts where the first fitting part and the second fitting part come into contact during fitting is determined to be larger than that of the first fitting part. A magnetic disk device that is designed to be selected by customers.