JPH06320372A - Processing method employing sucking device - Google Patents

Abstract

PURPOSE:To reduce the occurrence of deformation of the plane part of a processing member and to improve flatness by a method wherein the vicinity of the central part of the plane part of the processing member is sucked and a tool is moved toward an outer periphery from the vicinity of the central part of the plane part of the processing member. CONSTITUTION:The vicinity of the inner peripheral part of the back side of the plane part 3 of a magnetic disc 1 is brought into contact with the sucking part 5 of a vacuum chuck 2. When a vacuum pump is operated, the groove 6 of the sucking part 5 is brought into a negative pressure and the magnetic disc 1 is sucked and held at the vacuum chuck 2. Through movement of a tool 4 from the inner peripheral part of the magnetic disc 1 toward the outer periphery thereof, the plane part 3 of the magnetic disc 1 is processed. A strain generated owing to the cutting force and the cut heat of the tool 4 is prevented from being constrained but released since the outer peripheral part of the magnetic disc 1 is free and deformation is prevented from occurring to the plane part 3 of the magnetic disc 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method using an adsorption device, and more particularly to a processing method for a flat surface portion of a disk-shaped member such as a reference surface of a magnetic disk or a polygon mirror.

[0002]

2. Description of the Related Art Conventionally, as a processing method using an adsorption device, for example, the methods shown in FIGS. 5 and 6 are known.

This is because the vicinity of the outer peripheral portion on the back side of the magnetic disk 1 as a toroidal disk working member is adsorbed by a vacuum chuck 2 as an adsorbing device, and the vicinity of the outer peripheral portion is adsorbed to increase the adsorbed area, thereby increasing the magnetic field. The holding of the disk 1 is stabilized, the tool 4 is moved from the inner peripheral portion of the flat surface portion 3 of the magnetic disk 1 toward the outer peripheral portion, and the flat surface portion 3 is processed.

[0004]

In the above processing method, however, since the magnetic disk 1 is attracted and held in the vicinity of the outer circumference, the strain 3a generated by the cutting force and cutting heat of the tool 4 does not escape to the outer circumference. As shown in FIG. 6, it remains on the flat surface portion 3. Further, even when a part of the constraint is released and slippage occurs with the vacuum chuck 2, there is a problem that the strain 3a remains in the flat surface portion 3 and the flatness decreases.

In view of this, the present invention has been made for the purpose of providing a method of processing a flat surface portion which can obtain a highly accurate flatness.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention provides a method of adsorbing a processing member to an adsorption device and holding and processing the processing member, wherein A suction device that sucks the vicinity of the central portion by a suction device, moves the tool toward the outer periphery from the vicinity of the central portion of the flat surface portion of the processing member, and processes the flat surface portion of the processing member. This is the processing method used, and the vicinity of the outer peripheral portion on the back side of the processed member may be supported by the outer peripheral portion of the suction device to process the flat surface portion.

[0007]

In the above processing method, the vicinity of the central portion on the back side of the flat surface of the processed member is sucked by the suction device. And
By moving the tool toward the outer periphery from the vicinity of the central portion of the flat surface portion of the processing member, the strain generated during cutting can be released to the outside, and the flat surface portion of the processing member is not deformed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a method in which a magnetic disk 1 as a processing member is adsorbed by a vacuum chuck 2 as an adsorption device and a flat portion 3 is processed by a tool 4.

The magnetic disk 1 is a disk-shaped donut, and the vacuum chuck 2 is disk-shaped and serves to attract the magnetic disk 1 to a position corresponding to the vicinity of the inner peripheral portion of the magnetic disk 1. The adsorption part 5 is formed in a ring shape. A groove 6 is formed in an annular shape in the suction portion 5, and a suction port 7 is provided at a predetermined position of the groove 6, and the suction port 7 is connected to a vacuum pump (not shown).

Then, the vicinity of the inner peripheral portion on the back side of the flat surface portion 3 of the magnetic disk 1 is brought into contact with the suction portion 5 of the vacuum chuck 2, and when the vacuum pump is operated, the groove 6 of the suction portion 5 becomes a negative pressure and the magnetic disk 1 Are sucked and held by the vacuum chuck 2. Then, the tool 4 is moved from the inner peripheral portion to the outer peripheral portion of the magnetic disk 1 to process the flat surface portion 3 of the magnetic disk 1. Therefore, the distortion 3a due to the cutting force of the tool 4 and the cutting heat is released without being restrained because the outer peripheral portion of the magnetic disk 1 is free and the flat surface portion 3 of the magnetic disk 1 is not deformed.

FIG. 2 shows another embodiment of the present invention. In the vacuum chuck 2, an annular supporting portion 8 is formed at the same height as the adsorption portion 5 on the outer peripheral portion on the magnetic disk 1 side, and adsorption is performed. Part 5
An open portion 9 is formed between the support portion 8 and the support portion 8 to communicate with the atmosphere. Therefore, even if the cutting back force of the tool 4 causes a bend in the outer peripheral portion of the magnetic disk 1, the flatness of the magnetic disk 1 is not lowered because the magnetic disk 1 is supported by the supporting portion 8.

3 and 4 show the flatness of the magnetic disk 1 by the conventional processing method and the processing method according to the present invention. FIG. 3 shows the conventional one and FIG. 4 shows the one according to the present invention. There is. And, the conventional one shows a state in which the vicinity of the outer peripheral portion of the magnetic disk 1 is chucked, processed at a feed F50 and a cutting depth of 5 μm while being rotated at 2500 rpm, and measured by an interference fringe meter. As shown in FIG. 3, it can be seen that the interference fringes 3b are not parallel and have unevenness and thus have poor flatness. On the other hand, in the case of the processing method of the present invention performed under the same conditions, as shown in FIG. 4, the interference fringes 3b become parallel and the flatness is good.

[0013]

As described above, in the processing method according to the present invention, the vicinity of the central portion on the back side of the flat surface portion of the processed member is sucked,
Since the tool is moved toward the outer periphery from the vicinity of the central portion of the flat surface portion of the processing member, distortion due to cutting force and cutting heat is released at the outer peripheral portion of the processing member. Therefore, there is an excellent effect such that the deformation of the flat portion of the processed member is reduced and the flatness is significantly improved (the defective rate of 91% becomes 0%).

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the method of the present invention.

FIG. 2 is a schematic diagram showing another embodiment of the method of the present invention.

FIG. 3 is a state diagram showing the flatness of a magnetic disk processed by a conventional method.

FIG. 4 is a state diagram showing the flatness of a magnetic disk processed by the method of the present invention.

FIG. 5 is a schematic diagram showing a conventional method.

FIG. 6 is a plan view taken along line A of FIG.

[Explanation of symbols]

 1 magnetic disk 2 vacuum chuck 3 plane part 4 tool 5 adsorption part 8 support part

Claims (2)

[Claims] 1. A method for adsorbing a machining member to an adsorption device to hold and process the machining member, wherein the central portion of the back side of the plane portion of the machining member is adsorbed by an adsorption device, and the tool is flat on the machining member. A processing method using an adsorption device, characterized in that the flat surface portion of the processing member is processed by moving from the vicinity of the central portion of the part toward the outer periphery. 2. The processing method using the suction device according to claim 1, wherein the vicinity of the outer peripheral portion on the back side of the processing member is supported by the outer peripheral portion of the suction device, and the flat surface portion is processed.