JPS61136772A - Accurate processing device - Google Patents

Abstract

PURPOSE:To enable the surface of a work to be high efficiently and high accurately processed, by providing a means, which gives a self-induced vibration to pressure air containing an abrasive grain jetted to an air pocket in a movable body, and hitting the abrasive grain to the work by the synergism of injection impact and the self-induced vibration. CONSTITUTION:After a work 9 is mounted onto a table 2, a device, operating a pressure air source 6 and injecting pressure air, attracting an abrasive grain in a tank 4, into an air pocket 31 of a movable body 3 from a jet port 33 at a fixed pressure, floats the movable body by static pressure from a surface of the table 2. Here the device, supplying pressure air to a cylinder chamber 12 and applying a change part of the air as a load to an upper part of the movable body 3 so as to induce a pressure change in the air pocket 31 by this change part of the load, causes compressed air in the air pocket to generate a self-induced vibration. The synergism of this self-induced vibration and injection impact causes a fine abrasive grain in the air pocket 31 to collide against the work 9 on the table 2, processing a surface of the work 9 at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a precision processing device applied to, for example, a polishing device for optical parts, conductor wafers, magnetic heads, photosensitive drums for copying machines, and the like.

<Summary of the Invention> This invention involves mounting a workpiece on a table, and statically levitating a movable body having an air pocket on the lower surface corresponding to the workpiece by jetting pressurized air containing abrasive grains into the air pocket. In this method, self-excited vibration is generated in the compressed air in the pocket, and the surface of the workpiece is processed under the self-excited vibration.

<Conventional technology> Conventionally, micro processing using abrasive grains and clear can processing include:
This includes grooving, cutting, drilling, etc., which are performed by spraying fine abrasive grains onto the workpiece from a minute nozzle. In this method, jet abrasive grains are directly impinged on the workpiece, and the impact force is used to crush the surface of the workpiece. In addition, in lapping processing using abrasive grains, the rolling and scratching of the abrasive grains are applied to the workpiece, and the processing speed is extremely slow.
Since the load applied to the abrasive grains needs to be uniform throughout, it is difficult to mechanize it.

<Purpose of the Invention> The present invention generates self-excited vibration in compressed air, places a workpiece under self-excited vibration, and injects abrasive grains, thereby reducing the self-excited vibration of the gas, the collision force of the abrasive grains, and the crushing force. The purpose of the present invention is to provide a new precision machining device in which rolling and scratching forces effectively act on a workpiece, realizing highly efficient and highly accurate machining.

<Structure and Effects of the Invention> In order to achieve the above object, the present invention makes it possible to move a movable body having an air pocket on the lower surface communicating with a pressure air source up and down onto a table equipped with a chuck for fixing a workpiece. established,
An abrasive tank is connected to the air outlet of the large air pocket, and a control means for generating self-excited vibration in the compressed air in the pocket is provided.

According to the above configuration, the workpiece on the table receives jetted abrasive grains under self-excited vibration of compressed air in the air pocket,
The synergistic effect of jetting and self-excited vibration improves the collision and crushability of abrasive grains, achieving the effect of achieving the initial objective.

<Description of Embodiment> FIG. 1 shows an embodiment of a precision processing apparatus according to the present invention.
The processing apparatus of the present invention includes a table 2 for fixing a workpiece disposed in a main body 1, and an air pocket 31 provided on the lower surface of the table 2 and communicating with a pressure air source 6, so that the air pocket 31 is provided on the lower surface of the table 2 for fixing the workpiece. A movable body 3 floating under static pressure, an abrasive grain tank 4 disposed in communication with an air outlet 33 of an air pocket 31, and a control that applies a load to the movable body 3 to generate self-excited vibrations in the compressed air in the pocket 31. means 5.

The table 2 is a disk-shaped table, and the center of the disk is fixed to the upper end of a motor shaft 21, and the lower surface and outer circumference are supported by air bearings 22 connected to a pressure air source 6, making it rotatable. A suction type chuck 23 is provided at the center, and the chuck 23 is connected to an air intake source 25 via a solenoid valve 24 to suction and fix the workpiece 9 onto the table 2.

The movable body 3 has a cylindrical shape formed in the main body 1.
An air guide hole 32 is provided at the center of the shaft, one end of which is opened in the center of the air pocket 31 to serve as a blowout port 33, and the other end is connected through an air pipe 34. The table is connected to a pressure air source 6, and by injecting pressurized air into the air pocket 31, it levitates statically against the table 2 surface.

In addition, the movable body 3 is provided with a lower tank 4 on one side of the air guide hole 32, and the bottom of the tank is connected to the air guide hole 32 via a small hole passage 41. When passing through, the abrasive grains in the tank 4 are attracted.

The control means 5 includes a cylinder chamber 1 formed in the upper part of the movable body 3.
2 is connected to a pressure air source 6 via an air supply pipe 51 having a solenoid valve 52 on the pipe, and the solenoid valve 52 is opened and closed by an operating mechanism 7.

A filter 8 that surrounds the table 2 and goes around it once.
The outside of the filter 8 is opened to the outside of the main body to form an exhaust port 81, and the inside of the filter 8 has an abrasive grain reservoir 82.
is provided to take into consideration the exhaust of low-particle mixed air that is ejected from the floating gap between the table 2 and the movable body 3. Incidentally, the abrasive grains in the abrasive grain reservoir are recovered to the abrasive grain tank 4 after being regenerated as necessary or via a circulation path (not shown). 61 in the drawing.
62 and 63 are regulators disposed on the air pipes, each of which is set to an appropriate air pressure.

When the workpiece 9 is mounted on the table 2 and a constant pressure of air is supplied to the air pipe 34, the movable body 3 floats statically against the table 2 due to the balance between its own weight and the compressed air. Now, when pressurized air is supplied to the cylinder chamber 12, the variation in atmospheric pressure is applied as a load to the upper part of the movable body 3, and this variation in load causes pressure variation in the pocket 31, resulting in a variation in the floating clearance. At this time, when the pressure of the compressed air injected into the pocket is constant, the load fluctuation is input and the clearance fluctuation is the output, and the stability condition between input and output is not satisfied, and the air pocket 31. The compressed air inside and the movable body 3 generate self-excited vibrations.

Under the a-excitation cutting, abrasive grains are attracted and mixed in the pressurized air from the jet nozzle 33, and the abrasive grains are jetted against the corresponding workpiece 9 on the table 2.

The inside of the pocket is filled with an atmosphere of fine abrasive grains, and the surface of the workpiece 9 is processed by jetting collision, rolling, and scratching action.

FIG. 2 shows the crushing action of the abrasive grains 42 on the workpiece 9 when the abrasive grains 42 are injected by compressed air.
is being fired toward the workpiece, and the arrow P represents self-excited vibration inside the pocket, and the abrasive grains 42 have two effects on the surface of the workpiece 9: the action due to the firing and the action due to the self-excited vibration. The synergistic effect of colliding with the workpiece 9 crushes the surface with high efficiency, and the peening effect of the abrasive grains improves the wear resistance and fatigue strength of the finished surface. The surface can be processed uniformly.

FIG. 3 shows a processing situation corresponding to lapping, in which the workpiece 9 is assumed to be moving in the horizontal direction due to the rotation of the table 2. The pressure of the air pocket 31 applies uniform pressure to the abrasive grains 42 on the workpiece 9 as shown by arrow P, and
On the other hand, since the compressed air inside the pocket 31 flows out of the pocket 31, the abrasive grains 42 are rolled as shown by the arrow Pl.
It has a scratching effect. These abrasive grains simultaneously act on the surface of the workpiece 9 in the X and Y directions due to the movement caused by air flow and pressure and the rotational movement of the table.Moreover, the abrasive grains with small particle diameters create pressure between the large abrasive grains. In response to this, the hesitating motion is repeated to perform microscopic surface processing.

As described above, the present invention mounts a workpiece onto the table 2,
A movable body 3 having an air pocket 31 on the lower surface is arranged so as to be movable up and down in correspondence with the workpiece.

Pressurized air containing abrasive grains is ejected into the air pocket of the movable body 3 to cause it to float under static pressure, and the compressed air in the pocket generates self-excited vibration, thereby processing the surface of the workpiece under self-excited vibration. Therefore, the abrasive grains 42 collide with the workpiece 9 due to the synergistic effect of the jet impact force and self-excited vibration, realizing high-speed machining. Moreover, by controlling the gas temperature, a processing temperature suitable for the material of the workpiece 9 and surface processing can be set.

Further, the present invention achieves uniform jetting by providing a large number of jetting ports for abrasive mixed air, and is effective in J-tight machining.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of a precision processing apparatus according to the present invention, and FIGS. 2 and 3 are explanatory diagrams showing processing conditions. 2...Table 23...Chuck 3...
・Movable body 31...Air pocket 32...
・Air guide hole 33... Jet nozzle 4... Abrasive grain tank 5... Control means 6... Pressure air source agent Patent attorney Yu Mitsuru Suzuki "---,:
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Claims (4)

[Claims] (1) A table equipped with a chuck for fixing a workpiece on the upper surface, a movable body provided on the table with an air pot on the lower surface communicating with a pressurized air source and levitated against the table surface under static pressure, and an air pot of the air pot. A precision machining device comprising: an abrasive grain tank arranged in communication with a spout; and a control means for generating self-excited vibrations in the compressed air in the pocket. (2) The precision processing apparatus according to claim 1, wherein the table is supported by an air bearing and is connected to a rotational drive device. (3) The precision processing apparatus according to claim 1, wherein the workpiece fixing chuck is a suction type chuck that uses vacuum. (4) The precision machining apparatus according to claim 1, wherein the control means engages the upper part of the movable body with a cylinder chamber, and connects the cylinder chamber to a pressurized air source via a regulating valve.