JPH0320943Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention consists of a disk case 1 as shown in the drawing.
The disk 2 installed inside the disk case 1 consists of a disk-shaped seat 11 having a hole 9 in the center and a hub 12 that clamps the peripheral edge of the center hole 9 of the seat 11. This disk cartridge has an improved shape in the shape of the rotationally driving hole provided in the hub 12.

That is, in this type of disk cartridge, a central shaft insertion hole 22 is provided at the center of the hub 12, and a drive shaft insertion hole 24 is provided at one location on the outer circumference of the hub 12.
When loaded into the magnetic recording device, the central shaft 25 and the driving shaft 26 of the bifurcated drive shaft on the magnetic recording device side engage into the central shaft insertion hole 22 and the drive shaft insertion hole 24, respectively, to rotationally drive the magnetic disk 2. There are some that take the form of

However, the central shaft 25 and the drive shaft 26 are generally circular in cross section for the sake of processing accuracy, but conventionally, the central shaft insertion hole 22 is circular as shown in FIG.
A circular central shaft 25 is fitted into this circular insertion hole 22,
A drive shaft 26 is fitted into an oval-shaped drive shaft insertion hole 24 that is elongated in the radial direction. Therefore, there is a natural play in the engagement of the center shaft insertion hole 22 and the center shaft 25, so within the range of this play, the drive shaft insertion hole 22
When the drive shaft 26 comes into contact with the contact surface 32 with a radial misalignment, it has been found that a problem occurs in which track misalignment occurs. This is the central shaft 25 and the drive shaft 26
2 points P for the two insertion holes 22 and 24
This is due to contact at P2.

This invention focuses on the fact that the drive shaft 26 on the magnetic recording device side is inserted into the drive shaft insertion hole 24 of the hub 12.
in line contact at one point with the central axis 25 on the magnetic recording device side.
The hub 12 has a three-point contact configuration in which it makes line contact at two points with the central shaft insertion hole 22 of the hub 12, thereby ensuring that the entire hub 12, that is, the disk 2, is misaligned in the radial direction with respect to the bifurcated drive shaft on the magnetic recording device side. The purpose is to prevent

The details will be explained below based on the drawings.

In Figures 2 to 5, the disk cartridge of the present invention is made of plastic upper and lower cases 1.
A disk case 1 is a flat rectangular hard case type in which parts a and 1b are combined into a lid by ultrasonic welding at several points, and a magnetic disk 2 is rotatably housed in the disk case 1. Consisting of

The disk case 1 has a drive shaft insertion window 3 located near the center near the front, a magnetic head insertion window 4 located in front of the drive shaft insertion window 3 and long from front to back, and a magnetic head insertion window 4 located at the rear of the drive shaft insertion window 3. a small-diameter index hole 5, positioning holes 6, 6 located on the front left and right sides with different diameters on the left and right, and a write protection hole 8, located on the front left and right sides that can be opened and closed by members 7, 7 mounted inside the case. 8, and these windows and holes are provided vertically through each other.

The magnetic disk 2 includes a disk-shaped magnetic sheet 11 having a through hole 10 corresponding to the index hole 5 near a hole 9 provided in the center, and a hub 12 that sandwiches the peripheral edge of the central hole 9 of the magnetic sheet 11. Consisting of

Upper and lower cases 1a constituting the disk case 1,
On each inner surface of the magnetic disk 1b, annular walls 15, 15 concentric with the outer periphery of the drive shaft insertion window 3 are vertically spaced apart and protrude from each other, and the hub 12 of the magnetic disk 2 is The annular walls 15, 15 are located above the drive shaft insertion window 3 in the disk case 1.
Free movement in the radial direction is restricted by contact with the inner surface.

On the outer surfaces of the left and right side walls 16, 16 of the disk case 1, there are guide grooves 19 extending from the front end to the vicinity of the rear end.
19 are respectively formed in a recessed manner, and the guide grooves 19, 19 are used to insert the disc drive into a disk drive of a magnetic recording device.

It is also necessary to prevent dust from entering the inside of the disk case 1 through the index hole 5 and especially the magnetic head insertion window 4 when the disk cartridge is not in use. Therefore, a pair of upper and lower shutter members for opening and closing the magnetic head insertion window 4 and the index hole 5 are assembled inside the disk case 1, but these are omitted from the drawings.

In FIGS. 4 to 6, the magnetic disk 2
The hub 12 consists of an upper hub component 20 and a lower hub component 21 that are separately molded in plastic and are inseparably connected.
The peripheral edge of the center hole 9 of the magnetic sheet 11 is held between the opposing surfaces of the magnetic sheet 11 and the center hole 9 of the magnetic sheet 11 .

In FIGS. 6 and 7, a circular center shaft insertion hole 22 is provided in the center of the hub 12 so as to penetrate vertically, and a stepped surface 23 is provided at one location on the outer periphery of the insertion hole 22.
A drive shaft insertion hole 24 having a vertically symmetrical shape is formed partially through the drive shaft insertion hole 24 . The drive shaft insertion hole 24 is vertically symmetrical so that the disk cartridge can be used upside down.

When the disk cartridge of the present invention is loaded into a magnetic recording device, the bifurcated drive shaft on the magnetic recording device side is inserted into the central shaft insertion hole 22 and one of the upper and lower drive shaft insertion holes 24 of the hub 12, and the magnetic disk 2 is inserted. drive the rotation.

The bifurcated drive shaft on the magnetic recording device side projects a large-diameter central shaft 25 that engages into the central shaft insertion hole 22 and a small-diameter drive shaft 26 that engages into the drive shaft insertion hole 24 in the hub receiver that is rotationally driven. The drive shaft 26 is supported in a vertically movable manner and biased to protrude by a spring member, and the hub receiver receives and supports a disc-shaped reference surface 27 protruding from the upper and lower surfaces of the hub 12.
The cross-sectional shapes of the central shaft 25 and the drive shaft 26 are both circular.

In the principle diagram shown in FIG. 10, when the central axis of the central shaft 25, that is, the central axis of the hub 12 is the Z axis, and the two axes that pass through the Z axis and are orthogonal to each other are the X axis and the Y axis,
The central axis insertion hole 22 has two planes 29 and 30 that are parallel to the Z axis and are perpendicular to each other at a distance equal to the radius of the central axis 25 from the Z axis, and a plane whose radius is larger than the radius of the central axis 25 with the Z axis as the center. Large arc-shaped side 3
1, and has an axially symmetric cross-sectional shape with respect to the Y axis.

The drive shaft insertion hole 24 is located on the arc side surface 31 side, and the outer inner surface in the radial direction is a contact surface 32 parallel to the X axis and the Z axis.
It has a substantially rectangular shape that is long in the X-axis direction.

Then, at the upper side position in the hub rotation direction Q where the line L connecting the central axis 25 on the magnetic recording device side and the drive shaft 26 is inclined at a predetermined angle θ (15 degrees in the figure) with respect to the Y axis, the drive shaft 26 is circular. The outer circumferential surface is arranged so as to circumscribe the contact surface 32 of the drive shaft insertion hole 24 .

In this case, first, the central shaft 25 is fitted into the central shaft insertion hole 22 with a margin, and the drive shaft 26 is inserted into the hub 1.
2 and rotates in the Q direction, it fits into the drive shaft insertion hole 24 again with a margin. The insertion depth of the drive shaft 26 into the insertion hole 24 is such that it does not come into contact with the stepped surface 23, as shown in FIG. Drive shaft 26 fitted into drive shaft insertion hole 24
moves in the direction of arrow Q, and its circular outer peripheral surface makes line contact with the contact surface 32 at one point P1. Now drive shaft 2
6 is a rotational force F applied to the hub 12, that is, the magnetic disk 2.
Due to the Y-axis direction component FY of the rotational force F, the circular outer peripheral surface of the central shaft 25 comes into line contact with the two flat surfaces 29 and 30 of the central shaft insertion hole 22 at two points P2 and P3. Therefore, due to the contact between the three points P1, P2, and P3, the magnetic disk 2 is held without being displaced in the radial direction while the magnetic disk 2 is being rotated.

Incidentally, in FIG. 9, both hub components 20, 21
are in a relationship in which a fitting protrusion 34 provided on one side and a fitting hole 35 provided on the other side fit into each other. In the illustrated example, the insertion hole 22 is provided at the center of the lower hub structure 21, and a cylindrical fitting protrusion 34 is formed upright from the periphery of the insertion hole 22, and is formed at the center of the upper hub structure 20. A fitting hole 35 into which the fitting protrusion 34 fits is provided transparently,
Both hub components 20 and 21 are ultrasonically welded in a fitted state to be integrally coupled. Reference numeral 36 in FIG. 8 indicates the welded portion. Since the aforementioned drive shaft insertion holes 24, 24 are provided in advance in each of the hub components 20, 21, the two hub components 20, 21 are inserted into the hub so that these insertion holes 24, 24 are vertically and concentrically aligned. It is necessary to regulate the position so as not to shift in the direction of rotation. To this end, the opposing surfaces of both hub structures 20 and 21 are provided with positioning means by fitting the concave and convex portions as shown in FIGS. 6 and 9. In the illustrated example, the drive shaft insertion hole 2 is located across the central shaft insertion hole 22.
An elongated hole 37 that is long in the radial direction and short in the hub rotational direction is provided in the lower hub component 21 at a position 180 degrees opposite the upper hub component 20.
A round shaft 38 that internally fits into the opposing surface of the hub in the rotating direction.
is provided, and the uneven fitting between the elongated hole 37 and the round shaft 38 restricts the displacement of both hub components 20, 21 in the hub rotation direction.

In addition, although the illustrated example is as described above, it is not limited to this, and for example, the drive shaft insertion hole 24
may be formed to have an inner and outer penetrating shape without having a stepped surface 23, or when the disk cartridge is used inverted, the drive shaft insertion hole 24 may be formed in a bottomed shape from the upper and lower end surfaces 12a, 12a, respectively. It may also be in the form of

In addition, FIGS. 11 to 13 show different embodiments of the present invention.

In the case shown in FIG. 11, the two surfaces 29 and 30 of the central shaft insertion hole 22 sandwiching the Y axis are preferably parallel to the Z axis and are formed into convex curved surfaces. These surfaces 29 and 30 may be concave curved surfaces, and even with this, the same effect as in the above embodiment can be expected.

In the one shown in FIG. 12, one flat surface 29 is formed in the central shaft insertion hole 22, and this flat surface 29 and the arcuate side surface 31 are in line contact with the central shaft 25 at two points P2 and P3.

In the one shown in FIG. 13, the contact surface 32 of the drive shaft insertion hole 24 is formed into a plane parallel to the X and Z axes, and is an upper and lower through hole formed axially symmetrically with the Y axis.
The side surface 31 of the central shaft insertion hole 22 is formed into a polygonal shape in plan view, and the same effect as in the above embodiment can also be expected.

Furthermore, the inner peripheral surface of the central shaft insertion hole 22 may have a regular polygonal shape. In short, as mentioned above, 2
It is sufficient to install it inside the central shaft 22 at points P2 and P3.

As explained above, according to this invention, the dimensions are set so that the central shaft 25 and the drive shaft 26 on the magnetic recording device side can fit into the central shaft insertion hole 22 and the drive shaft insertion hole 24 of the hub 12, respectively, with a margin. After that, the drive shaft 26 is inserted into the contact surface 32 of the drive shaft insertion hole 24.
When a rotational force F is applied to the disk 2 by contacting it at one point P1, the Y-axis direction component FY of this rotational force F causes the inner surface of the central shaft insertion hole 22 to change the circular shape of the central shaft 25 at two points P2 and P3. It is assumed that it is inscribed in the outer peripheral surface. Therefore, the disk 2 is supported at three points, P1, P2, and P3, so that the disk 2 is supported on the drive shaft of the magnetic recording device.
Displacement movement in the radial direction, that is, track displacement, can be effectively and reliably prevented with a simple configuration. In particular, at the upper side position in the hub rotation direction Θ where the line L connecting the central shaft 25 and the drive shaft 26 is inclined at a predetermined angle θ with respect to the Y axis, the circular outer circumferential surface of the drive shaft 26 is the contact surface of the drive shaft insertion hole 24. 32 at one point P1, the drive shaft 26 can be securely inserted into the drive shaft insertion hole 24 with a margin without special consideration for the drive shaft 26. The drive shaft 26 can be reliably brought into contact with the contact surface 32 at one point even if assembling play and precision defects occur in various parts.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the principle of the shape of a conventional hub. Fig. 2 is an external perspective view showing an example of a disk cartridge to which the present invention is applied, Fig. 3 is a partially cutaway plan view, Fig. 4 is a sectional view taken along the - line in Fig. 2, and Fig. 5 is a FIG. 2 is a sectional view taken along line V-V in FIG. 2; Fig. 6 is a plan view of the hub, which is one of the constituent members of the present invention, Fig. 7 is a sectional view taken along the - line in Fig. 6, Fig. 8 is a sectional view taken along - The cross-sectional view taken along the line ``--'' and FIG. 10 are diagrams illustrating the operating principle of the hub. FIGS. 11 and 12 are plan views of hubs showing other embodiments of the present invention, respectively. FIG. 13 is a plan view showing still another embodiment of the present invention. 1... Disk case, 2... Magnetic disk,
3... Drive shaft insertion window, 4... Magnetic head insertion window,
DESCRIPTION OF SYMBOLS 11... Magnetic sheet, 9... Central hole of magnetic sheet, 12... Hub, 20, 21... Upper and lower hub components, 22... Central shaft insertion hole, 24... Drive shaft insertion hole, 25... Central shaft, 26... Drive shaft, 29,
30... Surface of the central shaft insertion hole, 32... Contact surface of the drive shaft insertion hole.

Claims (1)

[Claims for Utility Model Registration] A disk 2 is rotatably housed in a disk case 1 having a drive shaft insertion window 3 and a magnetic head insertion window 4, and the disk 2 includes a disk-shaped sheet 11 having a hole 9 in the center. It consists of a hub 12 that clamps the peripheral edge of the central hole 9 of the sheet 11, the end surface 12a of the hub 12 faces the drive shaft insertion window 3 of the disk case 1, and the hub 12 has a central shaft 25 on the magnetic recording device side. In a disk cartridge, a central shaft insertion hole 22 into which the magnetic recording device is inserted is provided at the center, and a drive shaft insertion hole 24 into which the drive shaft 26 of the magnetic recording device is inserted is provided at the outer periphery of the central shaft insertion hole 22. The central axis of the hub 12 in the shaft insertion hole 22 is the Z axis, and the two axes that pass through the Z axis and are orthogonal to each other are the X axis and the Y axis.
When used as a shaft, the central shaft insertion hole 22 has two inward contact points (P2, P3) parallel to the Z-axis and inscribed in the circular outer peripheral surface of the central shaft 25, and the drive shaft insertion hole 24 has Internal contact point (P2, P
3), has a contact surface 32 whose radially outer inner surface is parallel to the X-axis and Z-axis and circumscribed by the circular outer peripheral surface of the drive shaft 26, and connects the central shaft 25 and the drive shaft 26. At the upper side position in the hub rotation direction Q where the line L is inclined at a predetermined angle θ with respect to the Y axis, the circular outer circumferential surface of the drive shaft 26 is arranged in a circumscribed relationship with the contact surface 32 of the drive shaft insertion hole 24. , When the drive shaft 26 makes line contact with the contact surface 32 at one point P1, the central shaft insertion hole 22 is inserted into the central shaft 25.
A disk cartridge characterized in that internal contact points (P2, P3) of the disk cartridge are received and supported.