JPS59219155A - Mirror finishing machine - Google Patents

Abstract

PURPOSE:To make a hard, fragile work grindable in highly accurate and efficient manners, by using a slide table in a ball circulating system or the like as a feed guide in time of forced feed griding but in time of constant pressure buffing, using a journal air bearing for that. CONSTITUTION:A jig 15 fitted with a work 14 is attached to a shaft 16 and performs efficient grinding with forced feed machining by a feed screw 30, a motor 33 and a slide table 25 by constant pressure buffing. Next, the motor 30 is stopped, while the shaft 16 is fed to the side of a grinding wheel 35, making a journal air bearing 22 a guide, by a linear motor 26 via thrust air bearings 23a, 23b and thrust bearing parts 24a-24c, and constant pressure buffing takes place. Then, all the machining job is completed upon checkup with a linear scale 34a and a read head 34b. Thus a hard, fragile work can be ground in highly accurate and efficient manners.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a polishing machine capable of continuously performing forced feed grinding and constant pressure polishing.

Conventional configuration and problems Conventionally, fine and flat mirror finishing of hard and brittle materials such as ferrite, glass, and crystal has been performed by first performing rough processing by grinding, and then by constant pressure polishing or lapping using free abrasive powder. It was finished with borishing, etc. Grinding using forced feed has high processing efficiency, but the surface accuracy (flatness, surface roughness) is not sufficient, so the process has to be divided into several steps. In such processes, high accuracy is required for surface flatness and surface roughness, but on the other hand, when free abrasive powder is used, it is difficult to control the thickness of the workpiece, and the product quality In addition to being a cause of lower yields, it is not safe to use dedicated processing machines for each process, and it takes time to attach and detach from each dedicated machine, which is a factor in high costs.

In addition, in order to improve the above-mentioned drawbacks, a polishing machine that continuously performs forced-feed grinding and constant-pressure polishing while measuring the feed rate has been developed. The figure shows an outline of the construction method. 1 is a workpiece, and the part 2 is rough-machined with high efficiency by forced feed grinding, the part 3 is processed continuously by constant pressure polishing, and the part 3 is finished.

As shown in FIG. 2, the configuration of this polishing machine includes a shaft 5 that rotates the workpiece supported by hydrostatic air bearings 4a, 4b, 4c, and a motor 6 that rotates the shaft. A table 7 using a static pressure slide to prevent stick-slip during pressure feeding 9, and a screw 8 for forced feeding. The nut 9 and the motor 1o, the locking cylinder 11 for integrally moving the nut 9 and the table 7 during forced feeding, the linear motor 12 for constant pressure feeding, and the measuring device for measuring the amount of movement of the slide table. Particularly in high-precision machining, the static pressure slide table 7 is required to have high rigidity, which has been an obstacle to cost reduction.

Purpose of the Invention The present invention is intended to improve the above-mentioned drawbacks, and is capable of continuously performing forced feed grinding and constant pressure polishing (
It provides lJIIFf processing machines at low cost,
The static pressure slide table of the high-precision, high-efficiency polishing machine that can perform forced-feed grinding and constant-pressure polishing in succession, as shown in the conventional example, was replaced with a relatively inexpensive straight kite that uses a hole circulation linear guide, etc. It has the unique effect of achieving the same degree of precision as the other methods.

Composition of the Invention The present invention provides a feeding device that uses a spiral groove to strongly feed the air, a bearing mounted on the feeding device, and a bearing housing that freely rotates and freely moves in the direction of the axial force. A shaft supported by a bearing, a thrust bearing section that regulates the position of the shaft in the direction of axial force, a feed device that sends the thrust bearing section at a constant pressure in the axial direction relative to the bearing housing, and a thrust bearing section that controls the amount of movement of the thrust bearing section. It consists of a measuring instrument to be measured and a motor that rotates a shaft.Either a workpiece or a grindstone for polishing the workpiece is provided at one end of the shaft, and the grindstone for polishing the workpiece is placed opposite the shaft to process the workpiece. It is configured by providing a grindstone or a workpiece so that highly accurate polishing can be performed with high efficiency, and it can be manufactured at low cost.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a cross-sectional view of one embodiment of the present invention. This I71 polishing machine can process approximately 2as of ferrite.
4 +121 ground by 50-60μm, surface roughness R
0.05, ax that achieves a flatness of 1 μm or less. The workpiece 14 is pasted 9 on a jig 15, as shown in an example in FIG. 4, and is fixed by suction on the vacuum suction surface 17 of the shaft 16. The vacuum suction surface 17 is connected to a vacuum generator (not shown) via a groove 18 and a joint 19. The shaft 16 and the housing 20 are not in contact, but the gap 21 between them is approximately 10
The amount of air flowing into the groove 18 from the gap 21 is sufficiently small, and there is almost no decrease in the degree of vacuum. The shaft 16 is rotatably and axially movably supported on the housing 2o by a journal air bearing 22, and axial positioning is performed by thrust bearings 24a, 24b, 24c via thrust air bearings 23&, 23b. Go ahead and grab it. The thrust bearings 24a, 24b, and 24c are supported by the slide table 25 and can move 1 iJ in the axial direction.
The slide table 26 has high precision.

It does not need to be highly rigid. Thrust bearing portion 24a.

24b124C is driven in the axial direction by a linear motor 2 that can move in the axial direction by controlling the thrust by voltage using the journal air bearing 22 of the spindle as a guide.
6. The motor 27 that rotates the shaft 16 is
The motor housing is supported by the thrust bearing portion 24c and moves together with the shaft 16. The base 28 on which the above-mentioned shaft, housing, thrust bearing section, etc. are mounted is guided by ball circulation type feed guides 29a, 29b, and 29c, and is connected to a nut 31 by a feed screw 30 and a nut holder 32 attached to the base 26. and is forcibly sent by the motor 33. The amount of feed by the linear motor 26 and motor 33 is determined by the linear scale 34a attached to the thrust bearing 24c and the reading 9 fixed to the base.
The distance between the grindstone 35 for processing the workpiece and the jig 16 can be accurately read by the hand 34b. The grindstone 35 and the jig 15 that are not rotating are the jig that used the sound.
Drive the feed screw 3° with the motor 33 so as to pinch the blade with the sharpening edge 35, and reset the point at which the l-swivel notch is turned on to L on the linear scale 34a. To accurately measure the summation distance of a jig 15.

Further, the grindstone 36 and the jig 16 are eccentric, and as the partners rotate, the surface of the workpiece is processed evenly.

The operation of the two-axis opposed polishing machine configured as described above will be described below.

The jig 15 that has pasted the workpiece 14 is attached to the shaft 16, and after measuring the distance of movement with the grinding wheel 35 using the center knob, the jig 15 is forcibly fed using the feed screw 30 and the motor 33. Grinding is performed most efficiently to the point where only the amount of finish removed by constant pressure polishing is left. After forced feeding processing, the motor 30 is stopped, constant pressure polishing is performed by the linear motor 26, and the linear scale 34a and the reading gutter 3 are
4b, after confirming that the polishing has been performed to the finished product size 1, the machining is immediately completed and the machine returns to the pre-machining position and stops.

According to this embodiment configured as described above, the air bearing spindle on the workpiece pickup side of a two-axis opposed rotary precision grinding machine that performs forced feed milling and constant pressure polishing in succession. By making the radial bearing part and the thrust bearing part relatively movable in the axial direction, and by using the radial bearing part as a feed guide during constant pressure polishing, the air There is no need to use a bearing slide, and it is possible to manufacture a high-precision, high-efficiency polishing machine for abrasive materials at low cost.

In addition, in this example, the linear motor 26 was used for the 1' morning movement of the feed during constant-pressure polishing, or the amount of machining removed by constant-pressure first polishing was small, and one type or several types of workpieces were used. If the pressure does not need to be changed frequently with ridges, a spring may be used to drive the feed during constant pressure polishing, and the thrust bearing portion may be locked with an air ring or the like during forced feed machining.

Further, in this embodiment, the workpiece q7/J picking spindle side of the two-axis opposing type precision polishing machine was sent for processing, but the spindle on the grindstone side may be sent. In that case, 2 l
Even if the workpiece is fixed instead of the opposite type, the same effect will not be obtained.

Effects of the Invention As described above, the present invention uses a slide table with a high rigidity ball circulation system as a feed guide for strong feed grinding, and uses a journal air bearing of the spindle as a feed guide for continuous constant pressure polishing. Therefore, it has the advantage of being able to manufacture a high-precision, high-efficiency polishing machine for hard brittle materials at low cost, and its effects are significant.

[Brief explanation of the drawing]

Figure 1 shows high precision processing of hard and brittle materials using fixed abrasive grains. A schematic diagram of a method for highly efficient machining; Figure 2 is a cross-sectional view of a conventional high-precision, high-efficiency polishing machine; Figure 3 is a cross-sectional view of a polishing machine as an example of the present invention; FIG. 4 is an explanatory diagram showing an example of how the workpiece is attached, and FIG. 6 is a sectional view of the setup. 14... Workpiece, 15... Axis, 20
- Housing, 22...Journal air bearing, 23a. 23b, 23C... Thrust bearing section, 25...
・Slide table, 26... linear motor,
27...Motor, 28...Base,
30...Feed screw, 31...Nut, 3
2...Nut holder, 33...Motor, 34a...Linear scale, 34b...
...Reading head, 36... Grinding wheel. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A feeding device forcibly feeding by a spiral groove, a bearing housing mounted on this feeding device, a shaft rotatably and freely movable in the axial direction supported by an air bearing in the bearing housing, and a shaft that is supported by an air bearing in the bearing housing, and A thrust bearing section for regulating the position of the thrust bearing section, a feeding device for sending the thrust bearing section at a constant pressure in the axial direction relative to the bearing housing, a measuring device for measuring the amount of movement of the thrust bearing section, and a measuring device for rotating the shaft. A motor, a workpiece or a grindstone for polishing the workpiece is provided at one end of the shaft, and a grindstone or a grindstone for polishing the workpiece is installed opposite the shaft. Polishing machine installed.