JPH0120510B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a disk cartridge in which a disk is rotatably built into a disk case, and its main purpose is to achieve high accuracy in tracking and high positioning of the disk on the rotating shaft of a drive motor. shall be.

FIG. 1 shows an example of a disk cartridge to which the present invention is applied, which is a disk case 1.
and a disk 2 rotatably built into this.

The disk case 1 is a rectangular flat hard plastic case, and has a circular disk drive window 3 approximately in the center and a head insertion window 4 in the front of the window 3. It is formed in a penetrating shape. A shutter member 5 is attached to the front end of the disk case 1 so as to be slidable in the left and right directions.The shutter member 5 closes the head insertion window 4 when not in use, and automatically closes the head insertion window 4 when loaded into the disk drive. The head insertion window 4 is opened and slid open.

The disk 2 consists of a disk-shaped recording medium 7 for recording information signals, and a hub 8 fixed at the center thereof and facing the disk drive window 3. Although the recording medium 7 in the figure is a magnetic sheet, the present invention also envisages a case where the disk 2 is an optical disk.

The hub 8 has a spindle hole 9 in the center, and when the disk drive is loaded, the spindle 10 on the disk drive side fits into the spindle hole 9 through the disk drive window 3, and the hub 8 is thereby positioned. is chucked to the drive motor side, and the disk 2 rotates.

Methods for positioning and chucking the disk 2 include a method in which a metal plate on the hub 8 side is attracted by a magnet on the drive motor side, and a method in which both sides of the hub 8 are clamped between a hub holder having a spindle 10 and a collet. However, the present invention can be effectively applied to any of these typical methods and their modified forms.

The present invention provides a disk cartridge of this basic form, in which the spindle hole 9 of the disk hub 8 is
The focus was on

[Background technology]

That is, FIGS. 2 and 3 show the shape of a conventionally known disk hub 8,
The spindle hole 9 has two spindle receiving surfaces 12, 12 and a spring part 13, which are integrally molded from plastic. Each spindle receiving surface 12 is formed as a vertical surface having a certain extent, and the spring portion 13 shown in the figure is a protrusion integrally formed at the tip of an arm 14 that is cantilevered concentrically with the center of the hub, and extends in the radial direction. Elastically displaced. When the spindle 10 enters the spindle hole 9 of the disk hub 8, the spring portion 13 is elastically displaced and comes into elastic contact with a part of the outer circumference of the spindle 10.
With this, the spindle receiving surfaces 12, 12 are brought into contact with the spindle 10, and the hub 8 is positioned and held at three points: the movable contact point of the spring portion 13 and the fixed contact points on both the receiving surfaces 12, 12. .

Therefore, in order to ensure the positioning accuracy of the disk 2, it is necessary to mold the spring part 13 of the hub 8 and both spindle receiving surfaces 12, 12 with strict precision, and the receiving surfaces 12 must be made of a necessary and sufficient amount. In order to maintain strength, the wall portion constituting the receiving surface 12 must be formed to have a thickness commensurate with the thickness.

However, both spindle receiving surfaces 1 are thick.
2 and 12, conventionally, the receiving surfaces 12 would undergo heat shrinkage deformation during mold cooling, so-called sink marks, and as shown in FIG. 3, the axial direction (vertical direction) of each receiving surface 12 would The middle portion tends to be concave, and both upper and lower ends protrude toward the center of the hub.

In addition, the spindle 10 only extends into the spindle hole 9 up to an intermediate height between the upper and lower sides, and the spring portion 13 is located at the upper and lower center.

For this purpose, as shown in Figure 3, the spindle 1
This results in a situation in which the vertical outer peripheral surface of the spindle bearing surface 12 contacts only the lower end of each spindle receiving surface 12. In other words, the fixed contact point of each receiving surface 12 moves downward, and the line of action A of the spring pressure of the spring portion 13 and the line of action B of the reaction force from each receiving surface 12 are greatly separated vertically, and the hub 2 is A moment of movement in the C direction is always generated, and this causes the hub 2 to rotate when the hub 2 is driven to rotate, causing troubles such as track-off and track misalignment.

Such a problem can be solved by the fact that the spring part 13 is integrally formed of plastic into a thin plate shape through a slit, and the vertical surface of the spring part 13 facing the spindle hole 9 is brought into contact with the spindle 10 over its entire axial width. Even in the configuration in which a uniformly distributed load is applied, a moment that moves the hub 2 in the direction of arrow C is generated.

Further, even when the spindle receiving surface 12 is formed of a metal plate, it is almost impossible to finish the receiving surface 12 into a highly accurate vertical surface over the entire width in the axial direction, and the line of action of the spring pressure of the spring portion 13 A and receiving surface 12
It has been difficult to obtain a coincident state in which the line of action B of the reaction force from .

In other words, the conventional problem is that each spindle receiving surface 12
This is because it is difficult to form a vertical surface over the entire width in the axial direction, and the fixed contact points for positioning of each receiving surface 12 with respect to the spindle 10 are moved due to poor molding.

[Summary and purpose of the invention]

This invention focuses on this fact, and the disk
In order to ensure positioning accuracy of the hub 8, the spindle hole 9 basically has two spindle receiving surfaces 12, 12 and one spring portion 13, and the upper and lower portions of each receiving surface 12, 12 are Fixed contact points P ₂ and P ₃ for positioning with respect to the spindle 10 are provided at two locations, and the line of action A of the spring pressure of the spring portion 13 is the line of action B and B of the reaction force from the fixed contact points P ₂ and P ₃ . It is characterized by being located between.

That is, at least the spindle receiving surface 12,
Disc hub 2 where 12 is molded in plastic
In this case, even if the above-mentioned hollow-shaped sink mark occurs in the upper and lower intermediate portions of each receiving surface 12, it is allowed to occur.
In this case, since the upper and lower ends of each receiving surface 12 inevitably protrude, the protrusions at both ends are connected to the fixed contact point P ₂ ,
P ₃ , the length of the spindle 10 is set large so that the upper and lower ends of each receiving surface 12 contact the outer periphery of the spindle 10 at two points. Furthermore, the present invention provides spindle receiving surfaces 12, 12.
In cases where the receiving surface 12 is formed not only from plastic but also from a metal plate, etc., the upper and lower middle portions of each receiving surface 12 are positively recessed, and the upper and lower ends of each receiving surface 12 are shaped like other receiving surfaces. The present invention also includes a configuration in which the outer periphery of the spindle 10 is brought into contact with the outer periphery of the spindle 10 earlier.

It is advantageous to set the fixed contact points P ₂ and P ₃ at the upper and lower ends of each spindle receiving surface 12 in this way because it is particularly easy to ensure molding accuracy at these upper and lower ends. However, the fixed contact points P ₂ and P ₃ may be set vertically at the upper and lower intermediate portions of each spindle receiving surface 12, and in this case, there is no need to make the spindle 10 longer.

[Embodiment 1] FIGS. 4 and 5 show a first embodiment of the present invention, and the basic forms of the target disk cartridge and disk hub 8 are as described above. However, the reference numeral 17 is a metal plate that is integrally insert-molded on the lower surface side of the hub 8, and specifically, it is a magnetic stainless steel plate of SUS430 that also serves as reinforcement. The hub 8 is molded from a plastic material such as polyacetal or polyarylate which is highly moldable, and a free movement regulating rib 18 is integrally molded below the metal plate 17 at a quarter point position on an imaginary circumferential line concentric with the center of the hub. has been done. This rib 18 may be formed in an annular shape, and by loosely fitting into the disk drive window 3 and coming into contact with the opening periphery of the window 3, it prevents the disk 2, that is, the hub 8, from moving more than necessary. do. Then, when loaded into the disk drive,
The spindle 10 is inserted into the spindle hole 9 from the recording surface side (lower side) of the recording medium 7, and the hub 8 is adsorbed and coupled to the magnet on the drive motor side via the metal plate 17. There is.

The two spindle receiving surfaces 12, 12 in the figure are symmetrical with respect to an imaginary line passing through the center of the hub, and have a V-shape in plan view, and the center of the spring portion 13 is located on the imaginary line, and the spindle hole In the state in which the spindle 10 is engaged with the spring part 1
3 movable contact point P ₁ and both spindle receiving surfaces 12,
The basic configuration in which the hub 8 is positioned and set relative to the spindle 10 at three fixed contact points on the spindle 10 is followed.

Thus, in this example, as shown in FIG. 5, each spindle receiving surface 12 is formed so that its axially (vertically) intermediate portion is concave, and its upper and lower ends protrude toward the center of the hub. The cross-sectional shape of the receiving surface 12 may be obtained by molding the plastic so that it is a vertical plane and utilizing the sink marks mentioned above during molding, or by forming the cross-sectional shape of the protruding end surface of the upper and lower ends of each receiving surface 12. The dimensional tolerances may be set strictly so that the upper and lower intermediate portions have a concave shape, or the upper and lower intermediate portions of each receiving surface 12 may be molded with a mold to have a concave shape as much as possible. In any case, it is desirable that the molding be performed with strict dimensional accuracy, especially with the difference in the amount of protrusion at the upper and lower ends of each receiving surface 12 being 1/100 mm or less.

Then, insert the spindle 10 into the spindle hole 9.
When the spindle 10 is fully engaged,
At least the vertical outer circumferential surface of the upper end is in contact with the upper end of the spindle receiving surface 12. That is, the spindle 1 is placed on the upper and lower protruding ends of each spindle receiving surface 12 before the upper and lower intermediate parts.
Set fixed contact points P ₂ and P ₃ corresponding to 0. This can be achieved by making the length of the spindle 10 longer than the existing one or by reducing the vertical width of the spindle receiving surface 12.

Further, the spring portion 13, which is a projection integrally formed at the tip of the cantilever arm 14, is located between the upper and lower fixed contact points P ₂ and P ₃ of each spindle receiving surface 12. That is, the line of action A of the spring pressure of the spring portion 13 is located between the lines of action B and B of the reaction force from the fixed contact points P ₂ and P ₃ .

[Embodiment 2] FIGS. 6 and 7 show a second embodiment of the present invention, in which the spring portion 13 is connected to the slit 1.
The spring portion 1 is formed into a thin plate shape through the spring portion 5.
The disk hub 8 has a configuration in which the vertical surface 13a facing the spindle hole 9 of No. 3 contacts the spindle 10 with an evenly distributed load across the upper and lower widths, and the rest of the configuration is basically the same as that of the first embodiment. It is.

[Embodiment 3] FIG. 8 shows a third embodiment of the present invention, in which two linear protrusions 19 running in the circumferential direction are provided above and below the intermediate portion near the lower half of each spindle receiving surface 12. ，
19 are protruded in parallel, and the protruding end surfaces of each of these protrusions 19, 19 facing the center of the spindle hole 9 are fixed contact points.
They become P ₂ and P ₃ . This serves as a positioning abutment surface for the spindle 10, and the rest of the structure is the same as that of the first embodiment. Protrusion 19 in this case
may be a partially protruding protrusion instead of a linear protrusion. In this way, each spindle receiving surface 1
The upper and lower fixed contact points P ₂ and P ₃ in the receiving surface 12 may be set anywhere on the receiving surface 12 including the intermediate portion thereof. Furthermore, it is sufficient that the spindle 10 has a short engagement height similar to the conventional one.

[Other variations]

Although the illustrated examples are as described above, the present invention is not limited thereto. For example, the disk case 1 may be turned upside down and loaded into the disk drive. The hub 8 may be entirely made of metal plate, and both spindle receiving surfaces 12, 12
may be molded from plastic, and the spring portion 13 may be a leaf spring-like member formed separately and incorporated. Of course, the line of action A of the spring pressure of the spring portion 13 does not need to be exactly in the vertical center of the line of action B of the reaction force from the upper and lower fixed contact points P ₂ P ₃ of both spindle receiving surfaces 12, 12. It only needs to be located midway between the lines of action B and B. Furthermore, the contact points P ₁ , P ₂ ,
_P3 is a concept that also includes line contact and surface contact having a certain area in the circumferential direction.

〔Effect of the invention〕

As explained above, according to the present invention, the spindle 10 is placed at two locations above and below each spindle receiving surface 12.
Provide fixed contact points P ₂ and P ₃ for positioning against the
The line of action A of the spring pressure of the spring part 13 is the fixed contact point
It is assumed that it is located between the lines of action B and B of the reaction forces from P ₂ and P ₃ . Therefore, although the former line of action A and the latter line of action B are vertically shifted,
No moment is generated to tilt the disk hub 8 in one direction C, and the hub 8 relative to the spindle 10
Good positioning accuracy can be ensured. In addition, the fixed contact points P ₂ and P ₃ on each spindle receiving surface 12 are formed to protrude so as to come into contact with the spindle 10 before the other receiving surface parts, so that the fixed contact points P 2 and P 3 are
Unlike the conventional example, P ₂ and P ₃ do not move depending on the molding conditions. Moreover, the spindle receiving surface 12
It is not necessary to form this with high accuracy in a wide area across the entire top and bottom width direction, and the fixed contact point P ₂ ,
Since it is sufficient to tighten the molding accuracy only in the local portion of _P3 , the hub 8 can also be manufactured easily.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a disk cartridge to which the present invention is directed. 2 and 3 show a conventional disk hub, with FIG. 2 being a plan view and FIG. 3 being a sectional view taken along the line -- in FIG. 4 and 5 show a first embodiment of the present invention, FIG. 4 is a plan view of the disk hub, and FIG. 5 is a sectional view taken along the line -- in FIG. 4. 6 and 7 show a second embodiment of the invention, FIG. 6 is a plan view of the disk hub;
FIG. 7 is a sectional view taken along the line -- in FIG. 6.
FIG. 8 is a longitudinal sectional view corresponding to FIG. 5 of a disk hub showing a third embodiment of the present invention. 1...disk case, 2...disk, 8...
...Hub, 9... Spindle hole, 10... Spindle, 12... Spindle receiving surface, 13... Spring part, A... Line of action of spring pressure of spring part, B... Action of reaction force of spindle receiving surface Line, P ₁ ... movable contact point, P ₂ , P ₃ ... fixed contact point.

Claims (1)

[Claims] 1. The hub 8 of the disk 2 built into the disk case 1 has a spindle hole 9 into which a spindle 10 on the disk drive side can be inserted, and the spindle hole 9 has two spindle receiving surfaces 12, 12. and the spindle receiving surface 1 by pressing into contact with the spindle 10.
2 and 12 in contact with the spindle 10
3, fixed contact points P ₂ and P ₃ for positioning with respect to the spindle 10 are provided at two locations above and below each spindle receiving surface 12.
, and the line of action A of the spring pressure of the spring portion 13 is the line of action B of the reaction force from both fixed contact points P ₂ and P ₃ .
A disk cartridge characterized in that it is set to be located between B. 2. Claim 1, in which fixed contact points P ₂ and P ₃ are provided at the upper and lower ends of each spindle receiving surface 12.
Disk cartridge as described in section.