Polishing method for a workpiece and polishing tool used for the polishing method

Abstract

Provided is a polishing tool capable of forming a high-quality surface of a workpiece for a short period of time. A polishing tool includes: a rotation shaft arranged parallel to a sending direction of moving the polishing tool relative to a workpiece; and at least two polishing bodies. The polishing body includes a foamed resin such as a foamed polyurethane resin, and has an outer peripheral surface having a porosity higher than that of the polishing body. The polishing body includes a non-foamed resin such as a non-foamed polyurethane resin being a material more rigid than that for the polishing body. When polishing-processing, the polishing body performs polishing removal on a surface of the workpiece, and the polishing body smoothes a waviness formed on the surface through the polishing removal.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a polishing method and a polishing tool used for polishing workpieces including an optical element such as a lens or a mirror, and a die for molding an optical element.[0003]2. Description of the Related Art[0004]Nowadays, in a case of finish-polishing a surface shape of a so-called non-axisymmetric free-form surface different in curvature at each point of a workpiece including an optical element such as a lens or a mirror, and a die for molding an optical element, the polishing-processing is performed with use of a polishing tool having a contact area smaller than an area of a surface of the workpiece. The polishing tool has a configuration having a disk-like polishing body provided onto a rotation shaft, and is mounted to a polishing apparatus. When the polishing-processing is performed by the polishing tool of this type, an outer peripheral surface of the polishing body is brought int...

AI Technical Summary

Benefits of technology

[0010]Further, according to the present invention, there is provided a workpiece processing method for polishing-processing a surface of a workpiece, including; bringing a disk-like first polishing body and a disk-like second polishing body into press-contact with the workpiece, the first polishing body and the second polishing body being adjacently provided to the same rotation shaft and each including an outer peripheral surface serving as a work surface, and moving the first polishing body and the second polishing body relative to the workpiece in a direction parallel to the rotation shaft, to thereby process the surface of the workpiece, in which; the outer peripheral surface of the first polishing body is formed into a shape having a porosity higher than a porosity of the outer peripheral surface of the second polishing body, the second polishing body includes a material more rigid than a material for the first polishing body, and the second polishing body removes a waviness formed through processing performed by the first polishing body.

[0011]According to the present invention, the outer peripheral surface of the first polishing body is formed into the shape having the high porosity, and hence a film of polishing liquid is less likely to be formed between the surface of the workpiece and the outer peripheral surface of the first polishing body. As a result, floating of the first polishing body caused by the film is suppressed, and thus it is possible to achieve high polishing removal efficiency. Further, the second polishing body different from the first polishing body includes the material more rigid than a material for the first polishing body, and hence the outer peripheral surface of the second polishing body is less likely to be held in contact with a valley portion of the waviness, but more likely to be held in contact with a peak portion of the waviness, whereby the second polishing body has a high performance in smoothing the waviness. Further, the first polishing body and the second polishing body, which have different functions from each other, are adjacently provided to the rotation shaft, and hence it is possible to perform polishing removal and smoothing of the waviness at one time. As a result, it is possible to obtain a high-quality surface of the workpiece for a short period of time.

Problems solved by technology

As a result, productivity of the workpiece such as the optical element is reduced, and manufacturing cost of the workpiece is adversely affected.

As a result, a finished surface having polishing removal depths different from point to point is formed, and thus the quality of the surface of the workpiece is sometimes degraded.

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