JPS606945Y2 - 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.

In addition, 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 located at a position offset from the insertion hole 5 by a predetermined distance.
is formed.

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 from 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.

The liners 11 and 12 are provided to automatically remove dust and prevent dropouts 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 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
Elongated holes 14, 15, 16, 17 of the same shape extending in the radial direction of the magnetic disk 1 are formed in the magnetic disk 2, and in the combined state,
These slots are superimposed.

When mounted on the magnetic disk drive main body, the magnetic head comes into contact with the magnetic disk 1 through the elongated hole 17 of the lower shell 8 and the elongated hole 16 of the liner 12, and the elongated hole 14 of the upper shelf and the elongated hole 11 of the liner 11. The head pad is inserted through the elongated hole 15.

In addition, recesses 18 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, and the long holes 16, 17 for head insertion and the long holes 14, 15 for pad insertion.
The open state in which the slits 21 and 22 coincide with each other and the magnetic disk 1 is exposed to the outside, and 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. It is possible to select a closed state in which the magnetic disk 1 is slid to a position, the long diameters 14 to 17 are closed, and the magnetic disk 1 is covered by the shutter 20.

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 installing it in the disk recorder body. It is being

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 row of lower shells 8 is also corrected.

However, as is clear from FIG. 3C, if the lower shell 8 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 center plate 2 will be bent. The flange portion and the peripheral portion of the opening 9 of the lower shell 8 come into contact, resulting in an increase in load torque, and in extreme cases, a failure in which rotation stops occurs.

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, the bottom of each shell is molded so that the upper shelf is warped inward and the lower shell 8 is warped outward, but various manufacturing steps such as welding the liner, welding the upper and lower shells, and installing the shutter are performed. As a result, the warping condition changes, and there is a problem in that the lower shell 8 of the assembled magnetic disk device may warp inward.

Arc-shaped rib I of the lower shell 8 of the above-mentioned magnetic disk device
As shown in FIG. 4A, OA to IOD have a slight gap between their tips and the inner surface of the upper shelf.

Although not shown, the tips of the arcuate ribs provided on the upper shelf do not come into contact with the inner surface of the lower shell 8, leaving a slight gap.

Therefore, by making each of these arcuate ribs slightly higher than the distance between the peripheral parts of the upper and lower shells, the lower shell 8
It is conceivable to curve it outward.

However, in this case, the upper shelf also warps outward, and as shown in FIG. 4B, the center plate 2 is disengaged from the boss provided at the center of the upper shelf, and the center plate moves back and forth and left and right inside the shell.

This idea uses protrusions such as ribs formed on the inside of one shell to push the other shell open, and only the lower shell warps outward.

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. 5A and 5B, the ribs IOA to 10D of the lower shell 8 and the ribs 35A to 35D of the upper shelf are circularly located so as to surround the outer periphery of the magnetic disk 1.
The height of each of the ribs IOA to IOD and 35A to 3 is made larger than the opposing interval between the upper and lower shells at the peripheral edge.
Reinforcing ribs 36A to 36D are integrally formed on the inner surface of the upper shelf at a position outside 5D.

Each of the reinforcing ribs 36A to 36D has a shape extending in a diagonal direction of the shell.

The upper shelf and the lower shell 8 are welded together at four corners of the peripheral ribs, as shown by diagonal lines in FIG. 5B.

In this way, the reinforcing ribs 36A to 36D are attached to the upper shelf.
As shown in FIG. 5A, only the lower shell 8 is pushed apart by the ribs IOA to IOD, 35A to 35D, and the upper shelf is not deformed.

The amount of warpage is such that, for example, the end portion of the lower shell 8 differs by about 0.3 to 0.5 (mm) from a position where there is no warpage.

According to this invention, since the lower shell 8 is warped outward, load torque does not increase and failures such as failure to rotate do not occur.

Further, since only the lower shell 8 is deformed, there is no problem of the center plate 2 moving within the shell.

Furthermore, in order to reinforce the upper shelf, if the substantially cross-shaped reinforcing ribs 36A to 36D are used as in the above-mentioned embodiment, unlike simply increasing the thickness of the peripheral edge of the upper shelf, it is possible to increase the thickness during molding. It has the advantage of not causing sink marks.

Furthermore, as the lower shell 8 warps outward, a gap 37 is created between the shelf and the shell 8, as shown in FIG. 6, when viewed from the outside.

Therefore, as shown in FIG. 7, the ends of the bosses 38 and 39 formed on the shelf and the shells 8 may be abutted against each other and welded together, and the peripheral edges may be structured so that they overlap by forming a step on the upper and lower shells. .

Moreover, FIG. 8 shows another embodiment of this invention.

In this example, the upper and lower shells are combined by welding the ends of the bosses 38 and 39, and ribs 35A to 35C for pushing open only the upper shelf are provided, and further,
Ribs on the peripheral edge of the lower shell 8 and arcuate ribs IOA~
In addition to removing the IOD, the portion of the peripheral edge where the rib used to be is shortened to a position inside the side surface of the shell.

If the ribs are removed from the lower shell 8 in this way, it becomes easier to deform, and the reinforcement parts 36A to 3 of the upper shelf
There is no need to make 6D so thick.

Further, by adopting a bottom plate structure in which the lower shell 8 is located at a stepped portion of the peripheral edge of the upper shelf, there is an advantage that the dimensional accuracy of each of the shelf and 8 can be increased.

[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 FIGS. 3 and 4 are views of this magnetic disk device. 5 and 6 are cross-sectional views of the shell of one embodiment of this invention, a plan view of the inner surface of the upper shelf thereof, and a side view thereof, and FIG. 7 is a sectional view of another embodiment of this invention. FIG. 8 is a sectional view of a shell of still another embodiment of this invention. 1... Magnetic disk, 2... Center plate, 7... Upper shell, Death... Lower shell, 10A to IOD, 35A to 35D...・・・
・Rib, 34... Drive shaft, 36A to 36D...
...Reinforcement rib.

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 protrusion having a height that pushes open the other shell on one or both of the upper shell and the lower shell; and a reinforcing portion that mainly deforms the lower shell; A magnetic disk device installed in the upper shell.