JPS63312058A - Polishing machine - Google Patents

Abstract

PURPOSE:To carry out polishing with high accuracy by moving a workpiece with respect to a polishing plate while slightly floating it up from a polishing- plate surface by means of a fluid discharged out of small holes on the polishing- plate surface and making an abrasive liquid pass through between the workpiece and the polishing plate. CONSTITUTION:A workpiece 14 is very slightly floated up from a polishing-plate surface 17 by means of compressed air which is sent through a pipe 20 and discharged out of small holes 18, and moved along the polishing-plate surface 17 due to the rotation of a polishing plate 11 and the reciprocation of a holder 13. And, an abrasive liquid 22 which is discharged out of a polishing liquid nozzle 21 passes through between the workpiece 14 and the polishing plate surface 17. Hence, the surface of the workpiece 14 is ground by abrasive grains in the abrasive liquid 22 polishing the workpiece 14 to ultra-high accuracy. The accuracy and surface roughness at this time are better, the higher the accuracy of the polishing-plate surface 17 is and the smaller are the diameters of the polishing grains.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a polishing machine C for ultra-precision machining that mainly finishes optical parts and the like into flat surfaces.

Conventional techniques and problems A conventional polishing machine presses a workpiece held in holder C2 against a polishing plate, and polishes it by applying rotation, reciprocating motion, etc. between the two while adding a polishing agent liquid. . In this polishing, the abrasive particles in the abrasive liquid fit into relatively soft materials such as polyurethane sheets, pitch, and tin provided on the surface of the polishing plate, and these particles are rubbed against the workpiece. Therefore, this research is done! ! The machine has the characteristic that increasing the pressure to press the workpiece against the polishing plate increases the polishing speed, and conversely, decreasing this pressure improves the polishing accuracy (1 surface roughness).

The highest precision that can be obtained with this polishing machine is about 50 nm, and the surface roughness is about 5 nm, and higher precision cannot be achieved. This means that there is a lower limit to the pressing pressure mentioned above due to the weight of the workpiece, etc., and there is also a grinding plate table for abrasive particles. [(This is due to the polishing mechanism of double-insertion and rubbing, which has limitations on the surface precision of the polishing plate, the particle size of the abrasive particles, etc.)

Therefore, an object of the present invention is to obtain a polishing machine that realizes polishing with higher precision than was previously possible using a new polishing mechanism C2.

Means for Solving the Problems The present invention includes a polishing plate, a holder that holds a workpiece, and a holder that moves relative to the polishing plate while pressing the workpiece against the surface of the polishing plate. A large number of small holes are formed between the surface of the polishing plate and the workpiece (2) to allow polishing to occur while allowing the abrasive solution to pass through. This is a polishing machine characterized by having:

Function: Therefore, in the polishing machine of the present invention, the workpiece is floated from the fluid C2, so that the workpiece can be stably pressed against the polishing plate with ultra-light pressure.

Furthermore, this floating allows the abrasive liquid to pass between the polishing plate surface and the workpiece, and the abrasive particles do not fit into the polishing plate, but flow through the liquid and touch the workpiece, scraping the surface. Since polishing is performed, the processing accuracy depends on the surface accuracy of the polishing plate,
It is less affected by the particle size of the abrasive particles, and ultra-high precision polishing in molecular layer units becomes possible.

EXAMPLES Below, examples illustrating the present invention will be specifically described.

In this polishing filO, 11 is a polishing plate.

It rotates about a vertical axis 12. Reference numeral 13 denotes a holder, which holds the workpiece 14 by adhesively bonding it, is connected to the drive section tip 16 via a ball joint 15, and presses the workpiece 14 against the surface 17 of the polishing plate 11 by the drive section (not shown). It makes two reciprocating movements in the left and right directions C in the figure. 18 is a small hole, and the polishing plate 11
It opens in the surface 17 of the polishing plate 11, communicates with the space 19 formed in the polishing plate 11, and is further connected to a compression 81 (not shown) through a pipe 20 formed in the vertical shaft 12, for discharging compressed air. 21 is an abrasive liquid nozzle, from which an abrasive liquid 22 made of a lubricating liquid containing abrasive particles is discharged onto the surface 17 of the polishing plate 11. Since this polishing machine 10 has the above-mentioned configuration, processing is possible. The object 14 is polished by the compressed air released from the small hole 18.
The polishing plate 11 floats up a very small amount and moves along the polishing plate surface 17 due to the rotation of the polishing plate 11 and the reciprocating movement of the holder 13. Therefore, the abrasive liquid 22 passes between the polishing plate surface 17, and the abrasive particles in the abrasive liquid 22 scrape the surface and polish it with ultra-high precision. Note that the accuracy and surface roughness at this time do not depend greatly on the polishing plate and the particle size C2 of the abrasive particles as in conventional polishing machines, but the higher the surface precision of the polishing plate, the more the abrasive particles It goes without saying that the smaller the diameter, the better.

In the above example, the polishing plate rotates and the workpiece makes reciprocating motion, but it goes without saying that any movement can be used as long as the polishing plate and workpiece move relative to each other.

In addition to compressed air, the fluid may also be a gas such as nitrogen or a liquid such as a lubricating liquid.

Further, in the above example, processing is carried out while flowing an abrasive liquid onto the surface of the Tochi polishing plate, but it is also possible to perform processing by immersing the entire surface portion of the polishing plate in the abrasive liquid.

Effects of the Invention As described above, the polishing machine of the present invention moves the workpiece through the polishing plate 11 while floating the workpiece very slightly above the polishing plate surface using the fluid released from the small holes, and drains the polishing agent liquid. Since the abrasive particles are passed between the workpiece and the polishing plate so as to scrape off the workpiece, polishing with extremely high precision is achieved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of an embodiment of the present invention. 10.--polishing machine, 11---polishing plate, 12.-
...Vertical axis, 13-----Holder, 14--
-Workpiece, 15...Ball joint, 16-...Drive part tip, 17-...Surface, 18...Small hole, 19--Space, 20--Pipe , 21...
...Nozzle, 22---abrasive liquid.

Claims (1)

[Claims] 1. A polishing plate, a holder that holds the workpiece and moves relative to the polishing plate while pressing the workpiece against the polishing plate surface, and a holder that has an opening on the polishing plate surface and releases fluid to remove the workpiece. 1. A polishing machine characterized by having a large number of small holes that allow the surface of the polishing plate to levitate only slightly and perform polishing while passing an abrasive liquid between the surface of the polishing plate and the workpiece.