JPH065033A - Hub structure of magnetic disk - Google Patents

Abstract

PURPOSE:To prevent the deviation between the main body of a magnetic disk and the center of a hub even if shock such as falling is applied on a magnetic disk having the hub structure for rotating the magnetic disk by pushing and fixing the magnetic disk with a clamping part from the upper side on the upper surface of an armature part, which is driven and rotated with a driving motor, with the magnetic disk being aligned with the center. CONSTITUTION:A protruding part 1a is coupled into a central hole 3b of a magnetic disk 3. A clamping part 1 is coupled with an armature part 2 with a screw 4. A part, which is in contact with the entire surface of a chamfered part 3a around the central hole 3b of the magnetic disk 3, is provided in a part 1b of the clamping part 1, which receives the magnetic disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hub structure of a magnetic disk used as a storage medium of a magnetic disk device.

[0002]

2. Description of the Related Art Some magnetic disk storage devices that use a magnetic disk as a storage medium include one in which the magnetic disk is removable from the device, and one in which one disk is fixedly housed in the device and is not replaced.

In any case, it is necessary for the magnetic disk to be surely rotated by the drive motor with the center of the disk as the center of rotation. As a configuration for that purpose, for example, as disclosed in Japanese Patent Laid-Open No. 58-112184, a circular central hole is formed in the central portion of the magnetic disk main body with high precision, and the circular central hole is rotated by a drive motor. The disk-shaped drive part and the part around the center hole of the magnetic disk are sandwiched between the drive member and the disk-shaped clamp member so that the center of the center hole and the center of rotation of the drive part coincide with each other. A magnetic disk device is known in which a disk is pressed against a drive section to form a hub section of the magnetic disk, and the magnetic disk rotates integrally with the drive section without shifting the center of rotation of the magnetic disk.

In a magnetic disk device in which a magnetic disk is removable, as shown in FIG. 5, a cartridge 8 for accommodating a magnetic disk having the above-mentioned hub portion is inserted into a magnetic disk device (hereinafter referred to as a drive) 7 by pushing it from a door 7a. By doing so, the drive portion of the hub of the disk in the cartridge 8 is engaged with the member rotated by the drive motor provided in the drive 7 so as to be integrally rotatable at a predetermined position. .

In the magnetic disk device disclosed in the above-mentioned Japanese Patent Laid-Open No. 58-112184, an armature is integrally fixed to the outer surface of the drive section constituting the hub section of the magnetic disk, and the cartridge is driven. , The spindle of the drive motor provided on the bottom plate of the drive is fitted into the hole formed in the center of the armature and aligned, and the armature is rotated by the rotating part of the drive motor. When the drive motor is driven by being chucked by the disk, the drive unit and the magnetic disk body rotate together.

In the case of a magnetic disk fixed type drive,
It suffices to combine the above-mentioned drive unit with the rotating unit of the constant drive motor.

FIG. 4 shows an example of a conventional hub structure for a magnetic disk. In this example, the drive part is the disc-shaped armature part itself. The hub is a disk-shaped clamp 1
And a disc-shaped armature part 2. The opposite faces of the two discs are provided with protrusions provided on the magnetic disk and having a step for fitting into a central hole having chamfered portions on both sides. The protrusion 3 is fitted into the center hole of the disc, the disc 3 is sandwiched from both sides, the screw 4 is inserted from the upper surface of the clamp portion 1, and the screw 3 is screwed into the screw hole 6 formed in the armature portion 2 to clamp the disc 3. As a result, the disk 3 can rotate integrally with both parts 1 and 2.

Although not shown in FIG. 4, when the magnetic disk cartridge is mounted at a predetermined position of the drive, the rotating portion of the drive motor and the armature portion 2 are aligned with each other by aligning the spindle of the drive motor. Is fitted into a recessed hole provided at the center of the armature portion, and the like.

FIG. 6 is an exploded perspective view showing an example of the structure of a cartridge 8 for housing the magnetic disk 3 having the hub portion having the above structure. The case of the cartridge 8 consists of an upper case 8a and a lower case 8b, and the disk 3 has a lower case 8a.
It is housed in a shallow circular recess provided on the bottom surface of b. A head access door 8c is provided on a part of the side surface of the lower case 8b, and an actuator equipped with a read head at the time of reading is inserted between the upper surface of the disk 3 and the upper case 8a, and the disk is read from above the disk 3. The information stored in is read. A circular hole 8d is provided in the center of the lower case, the lower surface of the armature part 2 forming the hub of the disk 3 projects from the lower surface of the lower case 8b, and the lower surface of the armature part 2 projects from the lower surface of the lower case 8b. The lower surface of the armature portion 2 serves as a chuck surface with the spindle motor.

In the conventional hub structure shown in FIG. 4, the disk 3 is sandwiched between the clamp portion 1 and the armature portion 2 which are connected to each other by the screw 4, so that the disk and the clamp portion are arranged in the thickness direction. Although the armature parts cannot be displaced from each other, no strong deterrent force is exerted in the radial direction parallel to the surface of the disk 3, and the disk 3
There is some play between the center hole 3a of the disk and the protruding parts of the clamp part 1 and the armature 2. Therefore, if a large shock is applied to the disk when the cartridge containing the disk is accidentally dropped, the disk body There is a problem that the mutual positions of the clamp portion 3 and the armature portion 2 forming the hub 3 are displaced from the initial mounting state, and the runout of data becomes large.

When an actuator equipped with a read head seeks inward from the outer circumference, dust adhering to the disk 3 may be blown off by the head.
The dust hits the clamp portion 1 and remains on the upper surface of the clamp portion 1 and on the disk 3 around it. There is no problem if this dust remains at the position where it was attached, but the impact when the cartridge 8 is carried may cause the dust to attach to the data section again. In that case, scratch the head or disk. It may cause a bad read and prevent good reading.

Further, as shown in FIG. 4, when the screw 4 is inserted into the hole from the upper side of the clamp portion 1 and tightened in the screw hole of the armature portion 2, the lower surface of the enlarged head of the screw 4 and the clamp The surface of the portion 1 is rubbed to generate fine powder, which becomes dust and moves in the cartridge case, and falls onto the surface of the disk 3 and adheres thereto. Therefore, conventionally, as shown in FIG. 4, a circular seal 10 having substantially the same size as that of the clamp portion 1 is attached to the upper surface of the clamp portion 1 so that even if fine powder is generated when tightening the screw, it does not wrap around the upper surface of the disk 3. However, there was a drawback that it was troublesome and costly.

[0013]

SUMMARY OF THE INVENTION In view of the above problems of the conventional hub structure for a magnetic disk, the present invention provides a magnetic disk main body and a drive unit that constitutes the hub even when a large shock is applied to the magnetic disk. It is a first object of the present invention to provide a hub structure in which the center point of the head does not shift, and in a magnetic disk device in which a magnetic disk is housed in a cartridge case, when the head seeks, it is blown by an actuator with a head and clamped. A second object is to provide a hub structure in which dust adhered to a magnetic disk in the disk portion or its periphery does not adhere to the data portion of the disk again due to a shock while being carried and the head or disk is not damaged. When the screws that connect the two disk members that form the hub of the removable magnetic disk housed in the cartridge are tightened, Providing a hub structure without flowing around the disk surface fines generated by moving the cartridge case by rubbing between the surface of the head and the disc member and the third issue.

[0014]

In order to solve the above-mentioned first problem, a magnetic disk has a center hole having a chamfered part at its center, and a disk-shaped drive part rotated by the drive source. A hub structure having a disk-shaped clamp portion for fixing the magnetic disk to a driving member by pressing the magnetic disk whose center is aligned with the driving portion and one surface of which is in contact with the driving portion to the driving portion, It is characterized in that a portion of the clamp portion that receives the magnetic disk has a portion that contacts the chamfered portion around the central hole of the magnetic disk over the entire circumference.

The invention for solving the above-mentioned second problem is characterized in that an adhesive means is provided on the outer side surface of the clamp portion of the hub structure having the above construction.

In the invention for solving the above-mentioned third problem, a magnetic disk is housed in a case, and in the housed state, the outer surface of the drive portion constituting the hub of the magnetic disk having the above construction is punched in the case. In the case of the structure exposed from the circular hole provided, the screw connecting the drive unit and the clamp member penetrates from the outer surface of the drive unit, and the non-penetrating screw hole provided on the surface of the clamp unit facing the drive unit. It is characterized by being screwed into.

[0017]

According to the means for solving the first problem described above, the magnetic disk receiving portion of the clamp portion is brought into contact with the entire circumference of the chamfered portion around the central hole provided at the center of the magnetic disk to drive the clamp portion. Since the magnetic disk is fixed to the clamp portion and the drive portion in the radial direction, the center of the magnetic disk does not deviate due to an impact such as a drop.

By providing a taper at the abutting portion of the clamp portion around the central hole of the magnetic disk with the chamfered portion around the central hole of the magnetic disk, the taper is aligned with the circumference of the central hole of the magnetic disk. The contact portion of the clamp portion is in surface contact with each other, and the position is held more reliably.

Next, according to the means for solving the above second problem, when the head seeks, the dust blown by the actuator holding the head adheres to the outer surface of the clamp portion by the adhesive means. Even when the cartridge is carried, it is not detached from the clamp portion and attached again to the data portion.

According to the means for solving the third problem, the head of the screw connecting the clamp part and the drive part comes to the outer side of the drive member exposed from the circular hole of the cartridge case. At the time of fastening, even if the head of the screw and the outer surface of the drive unit rub against each other to generate fine powder, the fine powder does not go around into the cartridge.

Incidentally, in order to hold the clamp portion so that it does not move when the above-mentioned screw is fastened, it is preferable to provide a concave portion for hanging a finger or the like on the outer surface of the clamp portion.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing a hub structure of a magnetic disk according to an embodiment of the present invention. The hub structure of the magnetic disk of the present embodiment is similar to the conventional hub structure shown in FIG. 4, in which both sides of the center hole 3b of the magnetic disk 3 are provided with an appropriate taper chamfered portion 3a. The portion 1 and the armature portion 2 sandwich the magnetic disk 3 around the central hole 3b to form a hub. The surface of the armature portion 2 facing the disc 3 is provided with a protrusion 2b which can be fitted into the center hole 3b of the disc 3. The protruding portion 2b is provided with a shallow recessed portion 2c, leaving a protruding portion having a slight width around the periphery. On the other hand, the lower surface of the clamp portion 1 is provided with a protruding portion 1a that fits into the recessed portion 2c. The protrusion 2b of the armature portion 2 is fitted into the center hole 3b of the disc 3 from below, and the projection 1a of the clamp portion 1 is fitted into the recessed portion 2c of the armature portion 2 from above the disc 3. On the lower surface of the portion of the clamp portion 1 that protrudes radially from the outer periphery of the protruding portion 1a, a taper portion 1b having a taper around the center hole 3b of the disk 3 that is equal to the taper of the chamfered portion 3a.
When the protruding portion 1a of the clamp portion 1 is fitted into the recessed portion 2c of the armature portion 2, the taper portion 1b of the clamp portion 1 is provided in the chamfered portion 3a around the center hole 3b of the disc 3. Surface contact over the entire circumference. Therefore, when the clamp portion 1 and the armature portion 2 are fastened with the screw 4, the lower surface of the outer portion of the center hole 3b of the disk 3 is pressed against the flat portion on the outer side of the protruding portion 2b of the armature portion 2 to form the center hole 3b. The chamfered portion 3a on the upper side of the rim comes into pressure contact with the tapered surface 1b of the clamp portion, the disk 3 is sandwiched between the tapered surface of the clamp portion 1 and the armature portion 2, and is reliably positioned and held in the axial and radial directions of the disk. Even when an impact is applied by dropping the cartridge or the like, the rotation center of the armature portion and the rotation center of the disk 3 are held without being displaced in the surface direction.

The centering means for engaging the rotating portion of the drive motor and the armature is the same as that described with reference to FIG.

As shown in FIG. 2, the clamp portion 1 is pressed against the chamfered portion 3a of the disc 3 such that the outer diameter of the clamp portion 1 is larger than the diameter of the central hole 3b of the disc 3.
Smaller than the outer diameter of the chamfered portion 3a, without providing a tapered portion,
It is composed of a cylindrical surface and a flat surface, and the intersecting circular ridge lines are brought into contact with the chamfered portion 3a of the disk 3 over the entire circumference so that the clamp portion 1 and the armature portion 2 are fastened to each other for positioning and holding the position. It is also possible.

Returning to FIG. 1 again, an adhesive member 5 such as a double-sided adhesive sheet is attached so as to cover the upper front surface of the clamp portion 1. Therefore, when the disk 3 is mounted in the drive and is in a recording / reproducing state, when the head floats over the disk 3 and seeks from the outer circumference to the inner circumference, dust on the disk 3 is blown toward the center of the disk. If it collides with the upper surface of the hub portion 1, the dust is adhered to the adhesive member 5 and captured, and it is prevented that the dust is separated from the upper surface of the clamp portion 1 and adheres to the data portion again due to an impact when the cartridge is carried. To be done.

Further, as shown in FIG. 1, in the hub structure of the present embodiment, the screw 4 for fastening the clamp portion 1 and the armature portion 2 by sandwiching the disc body 3 is provided with the screw 4 from the lower side of the armature portion 2. After penetrating the hole through
It is fastened by screwing it into a non-penetrating screw hole 6 drilled from the lower surface of the clamp portion 1.

Therefore, when the screw 4 is fastened, the head of the screw 4 rubs against the lower surface of the armature part 2.
Since the lower surface of the armature portion is the chuck surface with the rotating portion of the spindle motor, it is completely exposed from the circular hole formed on the side of the cartridge case that is the lower side when mounted on the drive.

Therefore, even if fine powder is generated by rubbing the head of the screw and the lower surface of the armature part 2 when the screw 4 is fastened, it does not go around into the cartridge. Further, since the screw hole 6 is a non-through hole, even if fine powder is generated due to friction between the female thread surface of the screw hole and the male thread surface of the screw 4 at the time of fastening the screw 4, it does not appear on the upper surface of the clamp part. Absent.

However, as described above, when the screw 4 is inserted from the lower surface side of the armature part 2 to fasten the clamp part and the armature part, the clamp part 1 is fixed so as not to move by screwing. It is necessary to hold it, but if the upper surface of the clamp portion 1 is a flat surface, it cannot be caught and tends to be gripped by the finger on the peripheral surface of the clamp portion 1. In that case, the tip of a finger may touch the surface of the disk body 3 and damage the disk surface.

Therefore, as shown in FIGS. 3 (a) and 3 (b), two notches 1c are provided on the upper surface of the clamp portion 1 at symmetrical positions with respect to the center point, so that when the screw 4 is fastened, The disc surface can be reliably gripped without touching the disc surface with a finger or a tool.

[0032]

As described above, according to the invention described in claim 1 or 2, even when a large impact is applied to the magnetic disk, the centers of the members constituting the magnetic disk main body and the hub are not displaced. The magnetic disk rotates accurately around the center point, and it is possible to prevent an increase in data shake.

In particular, according to the second aspect of the present invention, by engaging the chamfered portion of the disc with the tapered portion of the clamp portion, the thickness of the hub can be reduced by the thickness of the chamfered portion of the disc. .

According to the third aspect of the present invention, dust blown off when the head seeks inward from the outer circumference can be captured by adhering to the surface of the clamp portion, so that the recording surface is separated by an impact or the like and is re-recorded. There is no risk of sticking to.

According to the fourth aspect of the invention, when the hub is assembled to the disk, the screw heads of the screws for fastening the clamp part and the armature part rub against the lower surface of the armature part exposed to the outside of the cartridge case, The fine powder generated at that time is prevented from entering the cartridge case.

According to the invention described in claim 5, when the screw is inserted from the lower surface side of the armature portion and screwed into the non-penetrating screw hole provided in the clamp portion as described above, the fingertip or the like does not touch the disk surface. Since the clamp portion can be held on the disk, damage to the disk can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a hub structure of the present invention.

FIG. 2 is a sectional view showing the configuration of another embodiment of the hub structure of the present invention.

3 (a) and 3 (b) are a plan view and a sectional view showing a notch on the upper surface of the clamp portion of the embodiment shown in FIGS. 1 and 2. FIG.

FIG. 4 is a sectional view showing a hub structure of a conventional magnetic disk.

FIG. 5 is a perspective view showing a state in which a cartridge is taken out of an example of a known magnetic disk device to which a magnetic disk is detachable.

FIG. 6 is an exploded perspective view showing the configuration of a conventional magnetic disk cartridge.

[Explanation of symbols]

 1 Clamp part (clamp member) 1a Projection part 1b Tapered surface 1c Notch 2 Armature part (driving member) 3 Magnetic disk 3a Chamfer part 3b Center hole 4 Screw 5 Adhesive member 6 Screw hole 7 Disk drive 8 Cartridge

Claims (5)

[Claims] 1. A hub structure of the magnetic disk of a magnetic disk device, comprising a magnetic disk rotated by a drive source as a storage medium, wherein information stored in the magnetic disk is read by a head, The disk has a central hole provided with a chamfered portion in the center thereof, and the disc-shaped drive unit rotated by the drive source is centered with the drive unit, and one surface is brought into contact with the drive unit. In a hub structure having a disk-shaped clamp portion that presses a magnetic disk against the drive portion to fix the magnetic disk to the drive member, the portion of the clamp portion that receives the magnetic disk is a chamfered portion around the central hole of the magnetic disk. And a hub structure having a portion that abuts over the entire circumference. 2. A portion of the clamp portion that abuts the chamfered portion around the center hole of the magnetic disk over the entire circumference has a taper that matches the taper of the chamfered portion around the center hole of the disk. The hub structure according to 1. 3. The magnetic disk hub structure according to claim 1, wherein the magnetic disk is housed in a case, and the head seeks between a surface of the side on which the clamp section abuts and the case. Hub structure characterized in that an adhesive means is provided on the outer surface of the hub. 4. The magnetic recording medium according to claim 1, wherein the magnetic disk is housed in a case, and an outer surface of a drive portion forming a hub of the magnetic disk is exposed from a circular hole formed in the case in the housed state. In the hub structure of the disk, the means for connecting the drive portion and the clamp portion is a screw that penetrates the drive portion from the outer surface and is screwed into a non-through screw hole provided on the drive portion side surface of the clamp portion. Hub structure characterized by that. 5. A concave portion that is provided on the surface of the clamp portion opposite to the drive portion so as to keep the clamp portion stationary during fastening with the screw.
Hub structure described in.