JPS63232975A - Fluid polishing method - Google Patents

Abstract

PURPOSE:To suppress damage to a minimum limit on a polished surface and to enhance quality of the finish polished surface, by forming an utmost limited polishing circumferential section on the peripheral surface of a rotary unit polishing tool by a fluid pressure increase-concentrating means so that a high dynamic pressure of fluid is generated in a fine polishing point even if the tool rotates in a low speed. CONSTITUTION:A rotary unit polishing tool 15 opposes its rotary circumferential surface approaching to a workpiece surface provided being arranged and immersed in polishing fluid, and this tool 15, which rotates its rotary circumferential surface relatively with the workpiece surface generating a dynamic pressure of the polishing fluid in a fine clearance between the rotary circumferential surface and the workpiece surface, polishes a fine amount of the workpiece surface. Here the rotary unit polishing tool 15 arranges in an equal space grooves 20 or protruding walls which converge in an opposite direction to the rotation toward the central part from the sideward peripheral edge of the rotary circumferential surface of the tool 15, and the tool 15, which increases a pressure of the polishing fluid to be converged along this rotary circumferential surface by these grooves 20 or protruding walls, enables a high dynamic pressure of fluid to be generated in a fine polishing point and a finished surface of high quality to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for locally micro-machining the surface of a machined surface of a workpiece, such as grinding or polishing.

(Prior Art) A method and an apparatus are known for removing minute amounts of the surface of a workpiece while the workpiece and processing tool are immersed in a suspension of hard fine powder for polishing. M
(Elastic Emissior Machine
For example, as shown in FIG. (0.1~0.O1μ) 31 is accelerated through the gap 33 between the polyurethane ball 30 and the processing surface 34, collides with the processing surface, and a small part of the fine particles of 0.1μ or less are processed. It contacts atoms on the surface and removes a small number of atoms. As can be seen from the figure, the processing tool 30 and the surface to be processed are maintained in a non-contact state. FIG. 6 shows an example of a device implementing this technique, in which a workpiece 32 and a polyurethane ball 30 are immersed in a container 36 filled with a processing suspension 35 on a moving table 35, and the polyurethane ball 30 is rotated. to remove minute amounts of atoms from the machined surface. In the figure, a polyurethane ball 30 is rotationally driven by a motor 37, and the motor 37 and the polyurethane ball 30 are automatically controlled by an NC device 38 based on a desired processing pattern. Since this method is non-contact processing, the processing phenomenon is stable, and by repeated scanning of the polyurethane ball, a processing amount linearly proportional to the number of times of scanning can be obtained. In the figure, P is a suspension circulation pump.

[Problem that the invention seeks to solve]

However, in the above method, if the rotation of the polyurethane ball is insufficient, the dynamic pressure acting on the polishing suspension flowing between the ball and the workpiece surface is insufficient, and the desired grinding effect cannot be obtained, which is extremely problematic. In some cases, direct contact between the ball and the liquid additive may occur, resulting in jP1 scratches on the machined surface, resulting in an unstable finished polished surface as a whole.

Means for Solving Problem C] The present invention solves the above-mentioned drawbacks and is particularly aimed at polishing surfaces to be processed such as aspherical lenses or mirrors. On the surface of the workpiece immersed in the turbid liquid,
Circumferential surfaces of rotary processing tools are closely opposed to each other, and a dynamic pressure of the liquid suspension is generated within a minute gap between the rotating circumferential surface of the processing tool and the surface of the workpiece, thereby forming a fluid on the surface of the workpiece. In a liquid polishing method for polishing a minute amount, a means for convergently increasing the liquid pressure of the suspension along the circumference is formed on the surface of the rotary processing tool by relative rotation with the surface of the workpiece. This is a liquid polishing method.

By the above-mentioned method according to the present invention, it is possible to locally remove a minute amount (about 0.1μ) from a small area on the surface of the workpiece, and it is possible to remove any aspherical shape with extremely excellent surface roughness. can be created.

〔Example〕

Examples of the liquid polishing method according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a polishing apparatus used to carry out the polishing method according to the present invention.
, a Y-direction moving table 3 placed on the table and moving in the Y direction, and a liquid tank 4 fixed on the Y-direction moving table 3. The X-direction and Y-direction moving tables 2 and 3 are driven by drive motors M and M2, respectively. A workpiece holding plate 7 is oscillated via a oscillating shaft 6 to a vertical plate 5 fixed vertically to the inner bottom of the liquid JfI4.
It is held so as to be able to swing around M6. The workpiece holding plate 7 has an L-shape, and its vertical surface is in contact with the vertical plate 5, and its horizontal surface is arranged with a gap necessary for rocking from the bottom of the liquid tank 4. The workpiece 8 is placed on the horizontal surface, and the workpiece holding plate 7 is swung by a motor M3. In addition, in this polishing method, since the rotary tool is rotated at high speed in the polishing suspension, the suspension inevitably scatters around, so in order to prevent this, the Preferably, an enclosure 18, shown in phantom, is provided.

The base column 9 extends perpendicularly from the rear end of the base plate 1, and the housing 11 is attached to the vertical surface 10 thereof.
A slide rail 12 that slides along 0 is provided. An air cylinder 13 is fixed to the upper end of the vertical surface of the base support 9, and the lower end of the piston rod 14 is connected to the housing 1.
It is fixed at 1. A rotary tool 15 according to the present invention that injects a polishing fluid onto the processing surface of the workpiece 8 is supported by a holder 16 and is swingable by a motor M4 via bearing means within the holder. 17 is each motor M, , M2, M3
, M, is a control device.

Note that the liquid polishing device configured as described above is based on a system that has already been adopted in the past, so a description of its functions will be omitted.

Next, the rotating body used in the liquid polishing method according to the present invention will be described.

In FIG. 2, a rotary body machining tool 15 according to the present invention is attached to a workpiece 8, which is attached to a workpiece holding plate 7 and whose position and orientation are changed, through a rotary drive shaft 16, and is placed in an optimal non-contact state with the machining surface. It is held by a pneumatic cylinder so that it is held in place.

3 and 4 show two examples of hydraulic pressure increasing means formed on the circumferential surface of a processing tool, the former showing a groove 20 and the latter a projecting wall 21, respectively. Although these means are linear chevron shapes, they may also be arcuate grooves or protruding walls 22 as shown in FIG.

During use, these tools generally rotate at several hundred to several thousand revolutions per minute, and the hydraulic pressure applied to the workpiece surface is adjusted at a constant value using an air cylinder. If the weight of the tool is large and there is a risk of contact machining if left unattended, counter pressure is applied to the air cylinder to maintain an appropriate load (for example, several hundred grams) at all times. The workpiece is NC-controlled so that machining pressure is always applied on the workpiece holding plate in the normal direction of the machining point. Furthermore, since the amount of machining is proportional to time, time control is performed to determine accurate machining allowance.

The rotary tool used in the method of the present invention is preferably made of hard resin such as nylon, urethane, Delrin, or the like.

■The shape of the tool is not limited to a part of a sphere, and a rotating body (such as a rotating dowel or a toric surface) can be used.

〔Effect of the invention〕

As described above, in the liquid polishing method according to the present invention, the polishing circumferential area limited to the limit by the liquid pressure increase concentration means is formed on the rotating circumferential surface, so that the rotating tool rotates at a relatively low speed. However, high liquid dynamic pressure is generated at the minute machining point, ensuring contact status and minimizing damage to the machining surface.

A high quality polished surface can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a liquid polishing device used to carry out the liquid polishing method according to the present invention, and FIG. 2 is a perspective view showing the processing of a rotary polishing tool and a workpiece according to the method of the present invention. FIGS. 3 and 4 show different embodiments of the hydraulic pressure -F increasing means formed on the circumferential surface of the rotary polishing tool, and FIG. 5 shows another embodiment of the hydraulic pressure increasing means. , 6 and 7 are diagrams respectively showing the working principle of a known EEM liquid grinding method and the schematic structure of an apparatus implementing the principle. 1...Base plate, 2.3...Moving table, 4...Liquid tank, 7...
・Workpiece holding plate, 8...Workpiece, 9・
...Base strut, 12 ... Air cylinder, 15 ... Rotating tool, 17 ... Control device, 18 ... Liquid enclosure, zO・・・・・・
...Hydraulic pressure rising groove, 21...Hydraulic pressure rising protruding wall, 22-...Fluid pressure rising means.

Claims (1)

[Scope of Claims] 1. The circumferential surface of a rotating body processing tool is closely opposed to the surface of a workpiece immersed in a polishing fine powder suspension, and the rotating circumferential surface of the processing tool and the In a liquid polishing method in which a dynamic pressure of the suspension is generated in a minute gap between the surfaces of the workpiece to polish a minute amount of the workpiece surface, the rotary processing tool is rotated relative to the workpiece surface. A liquid polishing method characterized in that a means for convergently increasing the liquid pressure of the suspension along the circumference is formed on the surface. 2. The means for convergently increasing the hydraulic pressure of the rotating body processing tool is arranged at equal intervals on the circumferential surface of the rotating body, converging in the counter-rotational direction from the side periphery toward the center of the circumferential surface of the rotating body. The liquid polishing method according to claim 1, wherein the liquid polishing method is a plurality of arranged suspension orientation parts. 3. The liquid polishing method according to claim 2, wherein the suspension orienting portion is a plurality of large mountain-shaped protruding walls on a circumferential surface. 4. The liquid polishing method according to claim 2, wherein the suspension orienting portion is a plurality of large mountain-shaped grooves on a circumferential surface.