JPH0422439Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a chucking mechanism for holding a magnetic disk in a predetermined position and rotating it at high speed. More specifically, the present invention relates to a magnetic disk chucking mechanism in which a drive pin is held by two independent mechanisms, an axial movement support mechanism and a radial movement support mechanism.

[Conventional technology]

As a mechanism for chucking a magnetic disk in a magnetic disk device such as a floppy disk drive, for example, as shown in FIGS. 4 and 5, a hub stand 12 is fixed to a spindle shaft 10 at the center of rotation. A hole 14 for engaging the drive pin is formed at a position eccentric from the hole 1.
There is a device in which a drive pin 16 is supported movably in the axial direction and radial direction of the hub stand 12 within the hub stand 12. A permanent magnet plate 18 for attracting the magnetic disk 20 is attached to the upper surface of the hub stand 12.

On the other hand, the magnetic disk 20 has a structure in which the center of a sheet-like disk disk 22 is held by a core metal 24, and a spindle shaft insertion hole 26 is formed in the center.
Then, drive pin insertion hole 28 is located at an eccentric position.
(See FIG. 5) is formed.

When the magnetic disk 20 is placed on the hub stand 12, the core metal 24 is magnetically attracted by the attractive force of the permanent magnet plate 18, and the spindle shaft 10 enters the spindle shaft insertion hole 26. At this time, drive pin 1
6 and the drive pin insertion hole 28 do not necessarily match, and if they do not match,
The drive pin 16 is pushed down by the core metal 24. At the same time, the spindle shaft 10 starts to rotate, so the magnetic disk 20 and the hub base 12 rotate relative to each other, and the drive pin 16 is guided to the position of the drive pin insertion hole 28 while rubbing against the core metal 24, so that they are aligned. At this time, the drive pin 16 protrudes upward. In this way, the two become one and form the magnetic disk 2.
0 rotates together with the hub stand 12, and the magnetic disk 20
The position will be guided to the specified position and fixed.

A leaf spring 30 is generally used to movably support the drive pin 16 in both the axial and radial directions. That is, a part of the leaf spring 30 is attached to the bottom of the hub stand 12, and the drive pin 16 is supported on the top surface. The state in which the drive pin 16 is pushed down is shown by phantom lines in FIG. Note that FIG. 5 shows a state in which the drive pin 16 has entered the drive pin insertion hole 28 and fixed the magnetic disk 20. The leaf spring 30 is designed in various ways in terms of shape so that it can be easily moved in the two directions.

[Problem that the invention attempts to solve]

The performance required of the drive pin in a magnetic disk chucking mechanism is to be able to move in the axial direction with as little force as possible, and to hold the magnetic disk securely so that the holding position does not change due to load fluctuations. That is, the drive pin should not tilt.

However, in the drive pin support structure using a single leaf spring as described above, the leaf spring is required to have the above two properties, and these contradictory properties create very difficult problems such as material selection and leaf spring shape. It was hot. Furthermore, it has been even more difficult to always meet these requirements at the mass production level.

The purpose of this invention is to eliminate the above-mentioned drawbacks of the conventional technology, to enable smooth axial and radial movement of the drive pin with as little force as possible, and to prevent rotational load fluctuations of the magnetic disk. To provide an improved chucking mechanism capable of firmly holding a magnetic disk without changing the holding position of a drive pin or tilting.

[Means for solving problems]

In this invention, a spindle shaft is fixed at the center of rotation, a hub stand has a hole for engaging a drive pin at a position eccentric from the center of rotation, and the hub stand is supported movably in the axial and radial directions within the hole. This assumes a structure with a drive pin.

This invention has a major feature in that the drive pin is supported by an axial movement support mechanism and a radial movement support mechanism.

Here, the axial movement support mechanism holds the drive pin slidably in the axial direction within the holder portion, and the first
The radial movement support mechanism supports the holder part movably in the radial direction by a holder support plate, and has a structure in which a second spring urges the tip part to protrude from the surface of the hub base. The structure is such that it is biased in one direction in the radial direction. Here, the drive pin consists of a stud that slides by fitting into the center hole of the holder part, and a bearing fixed to the stud, and the holder support plate has a tip end facing the hub base on the surface facing the hub base. It has a convex portion that comes into contact with the stand.

The above-mentioned holder portion is manufactured from synthetic resin, metal, or the like. Further, it is preferable that the first spring is incorporated into the holder portion as a coil spring.

[Effect]

The axial movement (pushing down) of the drive pin when the magnetic disk is attracted is only carried out against the elastic force of the first spring, so by using a weak spring member, it can be moved smoothly with a small force. can be moved to

Support for movement in the radial direction can be achieved by supporting the holder part with a sufficiently rigid member and biasing it with a second spring with appropriate springiness. Since the contact is made only through the convex portion, there is little frictional resistance and the drive pin is smooth, and since the drive pin is guided to slide with respect to the holder portion, it does not tilt.

In this way, in this invention, a movable support mechanism is provided for each necessary operation, and the necessary operations are realized by the combination of these mechanisms, making it possible to stably supply highly accurate products.

〔Example〕

1 to 3 show an embodiment of this invention. Basically, as in the past, a hub stand 12 is fixed to a spindle shaft 10 located at the center of rotation, and a hole 14 for engaging a drive pin is provided at a position eccentric from the center of rotation. This is a structure in which the drive pin 16 is supported movably in the axial and radial directions. A C-shaped permanent magnet plate 18 for magnetic disk attraction is provided on the upper surface of the hub stand 12 so as to surround the spindle shaft 10.

Now, the point where this invention is significantly different from the prior art is the support mechanism for the drive pin 16, in which the drive pin 16 is supported by two movable support mechanisms, namely, an axial movable support mechanism and a radial movable support mechanism. The point is that

The axial movement support mechanism includes a synthetic resin holder portion 32 that holds the drive pin 16 slidably in the axial direction, and a first spring 34 built into the holder portion 32.
The drive pin has a structure in which the tip end of the drive pin is urged to protrude from the surface of the hub base. The drive pin 16 consists of a stud 36 that fits into the center hole of the holder part 32 and slides, and a bearing 39 that is fixed at the upper end of the stud 36 via a connecting ring 38.A first coil spring 34 is attached to the outer periphery of the stud 36. wrapped. The stud 36 is the holder part 3
Because it fits into the center hole of 2 and slides along it,
The drive pin 16 is kept perpendicular to the holder portion 32 with high accuracy.

The radial movement support mechanism is composed of the holder portion 32, the holder holding plate 40, the second spring 42, and the like. The holder holding plate 40 has a substantially dogleg-shaped shape, and as can be seen from FIG. A spring 42 is connected. The other end of the second spring 42 is fixed to the lower surface of the hub base, so that the holder portion 32 is biased radially outward. A convex portion 44 is formed at an appropriate position on the holder support plate 40 facing the lower surface of the hub stand to reduce the frictional load during sliding. Note that since the holder support plate 40 is not required to have spring properties, it is made of a rigid member with sufficient wall thickness.

More preferably, the holder holding plate 40, the convex portion 44, and the holder portion 32 are integrally molded from synthetic resin, which reduces the number of parts and makes assembly extremely easy.

The basic operation of such a chucking mechanism is as follows. Drive pin 16 is axially movable. If the first spring 34 is sufficiently small but has enough springiness to allow the drive pin 16 to protrude, the drive pin 16 will be smoothly pushed downward by the slight force when the magnetic disk is attracted, and the drive pin 16 will be free. It returns to its original position (ie, when the position of the drive pin 16 matches the drive pin insertion hole of the magnetic disk).
Further, the holder portion 32 is driven radially outward by the elastic force of the second spring 42 to correctly hold the magnetic disk at a predetermined position. That is, the vertical movement of the drive pin 16 is controlled by the first spring 34, and the radial movement of the drive pin 16 is controlled by the second spring 42.
Since this invention has a separate mechanism for each necessary action, there is a high degree of freedom in selecting the performance, material, shape, etc. of each spring, making design and manufacturing easier, and allowing for high-precision springs. This will enable a stable supply of.

Note that this invention is not limited to the configuration of the above embodiment. For example, the holder portion may be made of metal and fixed to the holder support plate by caulking or the like.

[Effect of idea]

As described above, this device is a magnetic disk chucking mechanism configured to support a drive pin by an axial movement support mechanism and a radial movement support mechanism, so that the axial movement and radial movement can be minimized. It can be operated smoothly by force, and there is no risk of the drive pin tilting due to changes in the magnetic disk rotation load, and the magnetic disk can be held firmly and with high precision so that the holding position does not change, making it reliable. It has advantages such as being able to perform magnetic recording with high performance, being easy to design and manufacture, and excellent in mass production.

In this invention, since a bearing is used for the drive pin, the friction when the drive pin slides on the wall of the engagement hole from the time it is inserted into the engagement hole to the determined position of the engagement hole is reduced. , it is possible to reduce fluctuations in the generation timing of index pulses, suppress variations in the writing start position on the disk, and ensure disk compatibility. Furthermore, since the holder support plate is provided with a convex portion, it makes almost point contact with the hub stand, reducing the frictional load and allowing very smooth chucking operation.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing one embodiment of the magnetic disk chucking mechanism according to this invention, Fig. 2 is a cross-sectional view of its main parts, Fig. 3 is a plan view thereof, and Figs. 4 and 5 are conventional ones. It is a sectional view showing an example of a technique. 10... Spindle shaft, 12... Hub stand, 14
... Drive pin engagement hole, 16 ... Drive pin, 20 ... Magnetic disk, 32 ... Holder part, 34 ... First spring, 40 ... Holder support plate, 42 ... Second spring, 44...Protrusion.

Claims (1)

[Claims for Utility Model Registration] 1. A hub base having a spindle shaft fixed to the center of rotation and having a hole for engaging a drive pin at a position eccentric from the center of rotation, and a hub base having a drive pin engagement hole located eccentrically from the rotation center, and a hub base having a drive pin engagement hole located at a position eccentric from the rotation center, and a hub base having a drive pin engagement hole located at a position eccentric from the rotation center; In the device, the drive pin is held slidably in the axial direction within the holder portion and is biased by a first spring so that the tip portion protrudes from the surface of the hub base. and a radial movement support mechanism that supports the holder portion movably in the radial direction by a holder support plate and biases it in one radial direction by a second spring, The drive pin consists of a stud that slides by fitting into the center hole of the holder part, and a bearing fixed to the stud, and the holder support plate has a tip on a surface facing the hub base, and the tip of the stud is in contact with the hub base. A magnetic disk chucking mechanism with convex portions that come in contact with each other. 2. The mechanism according to claim 1, wherein the first spring is a coil spring and is installed in the holder part.