JP3295766B2 - Rotary cylinder of spindle mechanism and inspection method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating cylinder of a spindle mechanism in a magnetic disk inspection apparatus and a method for inspecting a disk mounting surface thereof.

[0002]

2. Description of the Related Art A magnetic disk (hereinafter, simply referred to as a disk) used as a storage medium of an information processing apparatus is mounted on a spindle mechanism of an inspection apparatus and rotated at each stage of a manufacturing process, and its defects and storage performance are reduced. Will be inspected. Although various types of spindle mechanisms have been devised, each of the spindle mechanisms includes a rotary cylinder that rotates by mounting a disk, and a central shaft that penetrates the center of the cylinder and clamps the mounted disk.

FIG. 3 shows an example of a spindle mechanism.
Is a vertical sectional view, and (b) is a partially enlarged view thereof. Fig. 3 (a),
In (b), the spindle mechanism is urged inward by a rotating cylinder 2 for the disk 1, a center shaft 3 penetrating the center thereof, having a pressing head 3a at the top, a ring wedge 4a, and a spring (not shown). Clamp 4 composed of a clamp 4b, a rotary cylinder 2 and a central shaft 3
And a spring 5 inserted between them. When the disc 1 is mounted, the center shaft 3 is first raised as shown on the right side of (a), and the bottom surface 1c around the center circle of the disc 1 is mounted on the mounting surface 2a at the upper end of the rotary cylinder 2. Then, when the center shaft 3 is lowered as shown on the left side, the clamp 4b is pushed outward by the ring wedge 4a, and the lower inclined surface 4c is formed at the edge of the center circle. The inclination angle θ is 25 °. Alternatively, the disc 1 is clamped by pressing the 45 ° chamfer 1a.

[0004]

In the spindle mechanism described above, the mounting surface 2a of the rotary cylinder 2 is finished in a plane as smooth as possible so as not to damage the disk 1 mounted and clamped thereon. ing. However, foreign matter may adhere to the mounting surface 2a, and the attached foreign matter damages the bottom surface 1c. In response to the recent increase in density, stricter defect inspection standards have been adopted for disks, and the damage on the bottom surface 1c is regarded as a defect and the quality rank of the disk deteriorates. Therefore, it is necessary to eliminate the damage by any method. Is needed. The present invention has been made in view of the above, and an object of the present invention is to provide a rotary cylinder having a mounting surface capable of eliminating damage to a bottom surface of a disk.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a rotary cylinder of a spindle mechanism and an inspection method thereof. The rotating cylinder has an inner diameter slightly larger than the diameter of the center hole of the disk, a thickness of about 1 mm, and is formed on the circumferential surface at the upper end, and corresponds to about 1 ° to 3 ° corresponding to the inch size of the disk.
And a ring mounting surface having a predetermined inclination angle in the range of The disk is placed with the ring-shaped intersection line where the bottom surface of the disk and the chamfer formed at the edge of the center hole intersect with the ring mounting surface, and the disk is clamped by the clamp. The above rotating cylinder is SUS440
The ring mounting surface is formed with high precision by using a stainless steel material as a raw material and polishing the upper end surface with diamond. Next, a method of inspecting the rotary cylinder is to apply an appropriate parallel light to the ring mounting surface formed on the circumferential surface at the upper end of the rotary cylinder and having an inclination angle in a range of about 1 ° to 3 °. The reflected light is projected on a screen provided at an appropriate distance, the diameter of the projected donut-shaped image is measured, and the quality of the inclination angle of the ring mounting surface is inspected.

[0006]

The stainless steel of SUS440 series, which is the material of the above-mentioned rotary cylinder, is the hardest of stainless steels and has good machinability, and is suitable for the ring mounting surface.
The rotating cylinder thus formed has an inner diameter slightly larger than the diameter of the center hole of the disk and a thickness of about 1 mm, and a circumferential surface at the upper end thereof has a diameter of about 1 mm corresponding to the inch size of the disk. The ring mounting surface having a predetermined inclination angle in the range of 3 ° to 3 ° is lapped and polished with diamond to be formed with high precision. The disk to be mounted is placed with a ring-shaped intersection line where the bottom surface and the chamfer at the edge of the center hole intersect with the ring mounting surface,
It is clamped by the clamp tool. Since the contact between the bottom surface of the disk and the ring mounting surface is a line contact with a very small contact area, there is very little risk of damage to the bottom surface of the disk due to attached foreign matter. In addition, since the inclination angle of the ring mounting surface is high within the range of about 1 ° to 3 °, even if the disk is eccentric and the contact position of the ring-shaped intersection changes, the inclination of the disk is extremely small. It does not interfere with the inspection. Next, in the inspection method, appropriate parallel light is applied to the ring mounting surface, and the reflected light is projected onto a screen provided at an appropriate distance, the diameter of the donut-shaped image is measured, and the ring mounting surface is measured. It is easily and accurately inspected whether or not the inclination angle of the surface is a predetermined value in the range of about 1 ° to 3 ° on the circumference and is uniform.

[0007]

1 shows an embodiment of a rotary cylinder 6 according to the present invention. FIG. 1 (a) is an external view and a sectional view of the upper part of the rotary cylinder 6, and FIG. It is the elements on larger scale of the ring mounting surface 6b. In FIG. 1 (a), the rotary cylinder 6 is made of a stainless steel metal cylinder of SUS440 series, and its outer diameter φ _d is slightly larger than the diameter of the center hole of the disk 1 and has a thickness t of about 1 mm. The cylinder 6a is formed. However, the lower portion is narrowed down to have the same diameter as the conventional rotary cylinder 2 shown in FIG. 3 (a), and a center shaft 3, a clamp portion 4 and the like are provided. The circumferential surface at the upper end of the upper cylinder 6a is lapped and polished with diamond to form a ring mounting surface 6b having an inclination angle δθ of about 1 ° to 3 ° with high precision. The inclination angle δθ differs depending on the inch size of the disk 1. For example, in the case of 2.5 inches, δθ = 2 ° is appropriate, and the allowable deviation is ± 1 ′. The reason for setting the tolerance to a small ± 1 '
If δθ differs depending on the position on the circumference, the disk 1 is inclined, so that this is prevented. As described above, since the inclination angle δθ requires high accuracy, the ring mounting surface 6b is inspected by the inspection method of the present invention when the ring mounting surface 6b is polished.
In FIG. 1 (b), the chamfers 1a and 1b which are inclined at an angle θ of 25 ° or 45 ° are provided at the edge of the center circle of the disk 1 as described above. Assuming that the intersection line between the lower chamfer 1b and the bottom surface 1c is 1d, the intersection line 1
d has a ring shape, which comes into contact with the ring mounting surface 6b, and the disk 1 is mounted on the rotary cylinder 6. In this case, when the disk 1 is eccentric, the contact position of the intersection line 1d moves, for example, by a distance R, and the height decreases on the left side of the disk 1 and increases on the right side, and the disk 1 tilts to the left. However, since the inclination angle δθ is as small as about 1 ° to 3 °, the height change is small even if the contact position moves, so that the inclination of the disk can be ignored.

FIG. 2 shows an embodiment of the method for inspecting the rotary cylinder 6 of the present invention. In FIG. 2 (a), the ring mounting surface 6b of the rotary cylinder 6 irradiates a suitable collimated light L _T. The reflected light has a donut shape and projects the image Q on a screen S provided at an appropriate distance D. By measuring the inside diameter phi ₁ and the outer diameter phi ₂ of the plurality of directions of the image Q, the inclination angle δθ is the entire area of the circumference, whether it is a predetermined angle and the deviation is close inspection. FIG. 2 (b) shows a simple inspection method, in which sunlight is applied to the ring mounting surface 6b through a window, and reflected light is projected on a wall. In this case, assuming that δθ = 2 ° and the distance D 太 陽光 1 m, since there is a non-parallel component in sunlight, the inner diameter φ _{1 of the} image Q = 155 mm and the outer diameter φ ₂ = 175
mm is a correct value.

[0009]

As described above, in the rotary cylinder according to the present invention, the ring mounting surface formed on the upper end surface of the rotary cylinder is made of SUS440 stainless steel, which is very hard, so that it has very little wear. . Also, since the ring-shaped intersection line of the chamfer and the bottom surface of the disk makes line contact with the ring mounting surface, the contact area is very small, and there is no danger that the bottom surface of the disk may be damaged by foreign matter adhering. Since the inclination angle is extremely small, and the inclination angle is a predetermined value within a range of about 1 ° to 3 ° and has high accuracy, even if the disk is eccentric, the inclination is extremely small and does not hinder the inspection. This greatly contributes to the disk inspection device. In the inspection method, appropriate parallel light is applied to the ring mounting surface, the reflected light is projected on a screen, the diameter of the donut-shaped image is measured, and the inclination angle of the ring mounting surface is about 1 °. It is checked whether the value is a predetermined value in the range of ° to 3 °, and is effective as a simple and accurate inspection method of the ring mounting surface.

[Brief description of the drawings]

1A and 1B show an embodiment of a rotary cylinder 6 according to the present invention, wherein FIG. 1A is an external view and a sectional view of an upper portion of the rotary cylinder 6, and FIG. It is the elements on larger scale of the ring mounting surface 6b which was done.

FIGS. 2A and 2B show an embodiment of a method for inspecting a rotary cylinder 6 according to the present invention, wherein FIG. 2A is a diagram illustrating the principle of the inspection method, and FIG.

3A and 3B show an example of a spindle mechanism for a magnetic disk, wherein FIG. 3A is a vertical sectional view, and FIG. 3B is a partially enlarged view thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic disk, simply disk, 1a, 1b ... Chamfer, 1c ... Bottom surface, 2 ... Conventional rotary cylinder, 3 ... Center axis, 3a ... Pressing head, 4 ... Clamp part, 4a ... Ring wedge, 4b ... Clamping tool .., 4c: inclined surface, 5: spring, 6: rotating cylinder of the present invention, 6a: upper cylinder, 6b: ring mounting surface, φ _d : outer diameter of rotating cylinder 6, t: thickness of upper cylinder, θ: inclination angle of the chamfer, the inclination angle of the .delta..theta ... ring mounting surface, R ... eccentricity of the disk 1, L _T ... parallel light, D ... distance, S ... screen,
Q: image, φ ₁ : inner diameter of image, φ ₂ : outer diameter of image.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shuji Banno 2-6-2 Otemachi, Chiyoda-ku, Tokyo Inside Hitachi Electronics Engineering Co., Ltd. (56) References JP-A-4-38752 (JP, A) JP-A-4-38753 (JP, A) JP-A-1-134773 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/84 G11B 23/00 G11B 23/04 B23Q 3/12 B23B 31/02

Claims (3)

(57) [Claims] 1. A spindle mechanism comprising: a rotary cylinder having a mounting surface for a magnetic disk to be inspected; and a central shaft penetrating through the rotary cylinder and having a clamp for the magnetic disk, wherein the rotary cylinder comprises: An inner diameter slightly larger than the diameter of the center hole of the magnetic disk;
A thickness of about 1 mm, formed on the circumferential surface at the upper end, and about 1 ° to 3 ° corresponding to the inch size of the magnetic disk.
A ring mounting surface having a predetermined inclination angle within the range of °, a bottom surface of the magnetic disk and a ring-shaped intersection line where a chamfer formed at an edge of the center hole intersects,
The rotating cylinder of a spindle mechanism, wherein the magnetic disk is mounted in line contact with the ring mounting surface and clamped by the clamp. 2. The ring mounting surface according to claim 1, wherein the rotating cylinder is made of stainless steel of SUS440 series, and an upper end surface thereof is polished with diamond to form the ring mounting surface with high precision. Rotary cylinder of spindle mechanism. 3. A ring mounting surface formed on a circumferential surface at an upper end of a rotary cylinder of a spindle mechanism and having an inclination angle in a range of about 1 ° to 3 °, and applies an appropriate parallel light to the ring mounting surface. And projecting the reflected light on a screen provided at an appropriate distance, measuring the diameter of the projected donut-shaped image, and inspecting the inclination angle of the ring mounting surface. Inspection method for rotating cylinder of spindle mechanism.