JPH02145251A - Finishing device for rotating curved face - Google Patents

Abstract

PURPOSE:To subject a 2nd rotating curved face to polishing with hyperprecision by positioning a 1st rotating curved face formed on a tool and 2nd rotating curved face formed on the body to be worked by non-contact type radial bearing and thrust bearing and constituting so as to feed a polishing liquid to the 2nd rotating curved face from the feeding hole of the 1st rotating curved face. CONSTITUTION:A tool 9 is supported by positioning it in a non-contact state on a support block 4 by a radial air bearing 11 and thrust air bearing 12 via an axial body 7. After positioning the tool 9 thus it is rotated by actuating a motor 25, a polishing liquid L is fed to a flow-in pass 18 as well and flowed out from the feeding hole 19 opened on the 1st rotating curved face 9a of the tool 9. Accordingly, the free abrasive grain contained in the polishing liquid L is collided with the 2nd rotating curved face of the body 22 to be worked and this 2nd rotating curved face 22a is polished with hyperprecision in Angstrom order.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a processing device for finishing a rotating curved surface formed on, for example, an X-ray mirror used in an X-ray microscope.

(Prior technology) X-rays have a shorter wavelength than visible light and a greater penetrating power than electron beams, and it is also possible to identify specific elements using the element's unique absorption edge and fluorescent X-rays. , has become an important means of obtaining information about objects at the atomic level.

However, in the X-ray region, the refractive index of materials is extremely close to 1, making it difficult to manufacture refractive lenses and direct-incidence reflecting mirrors for the visible region.

Therefore, X-ray microscopes that are currently being put into practical use utilize the fact that when X-rays are incident close to a mirror surface, they are totally reflected. A Wolter type optical system as shown in FIG. 3 forms the mirror surface at this time. It consists of a hyperboloid of revolution S)l and an ellipsoid of revolution SP that share one focal point F1. The focal point F2 is taken as an object point, and the X-rays emitted from this point are reflected by the two curved surfaces and imaged at the focal point F3.

The reason why the reflective surface is used twice in this way is to reduce distortion of the image of an object point far from the optical axis. Furthermore, in such an X-ray mirror for an X-ray microscope, as shown in FIG.
In order to use imaging, light shielding plates E for shielding direct X-rays C from entering the X-ray detector B are provided before and after the mirror. The reflected XiA is made to enter and exit through a slit G between these light-shielding plates E and the cylindrical mirror. Note that this slit G is required to be coaxial with the entire mirror with an accuracy of several μm to IQum.

By the way, the resolution of an X-ray microscope is the above-mentioned hyperboloid of revolution SH
is determined by the machining accuracy of the spheroidal surface SP. In general, mirror surface accuracy can be divided into surface roughness that is close to the wavelength of X-rays and shape accuracy that has a relatively large period.

In order to realize an ideal X-ray microscope, several degrees of surface roughness and shape accuracy of sub-μm order are required.

However, the hyperboloid of revolution SH and the ellipsoid of revolution SP, S
- It is extremely difficult to process any rotating curved surface with the shape accuracy and surface roughness accuracy of the order, and conventional processing technology could not adequately handle it. .

(Problem to be solved by the invention) In this way, in the past, rotating curved surfaces such as hyperboloids and spheroidal surfaces of X-ray mirrors could be processed with shape accuracy on the sub-μm order and surface roughness accuracy on the human order. It was difficult to do so.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a finishing machine capable of processing a rotating curved surface with high precision.

[Structure of the Invention] (Means and Effects for Solving the Problems) In order to solve the above problems, the present invention provides a method in which a first rotational curved surface is formed, the first rotational curved surface is formed on a workpiece, and the first rotational curved surface is formed on a workpiece. a tool provided opposite to a second rotational curved surface onto which the first rotational curved surface is transferred in a non-contact state; a drive mechanism that rotationally drives the tool or the workpiece; and a second rotational curved surface of the workpiece. a non-contact type radial bearing for positioning the rotating curved surface and the first rotating curved surface of the tool in the radial direction; a non-contact type thrust bearing for positioning the rotating curved surface in the thrust direction; and an opening in the first rotating curved surface of the tool. and a supply hole for supplying a polishing liquid containing free abrasive grains to the second rotating curved surface of the workpiece. With this configuration, the second rotating curved surface of the workpiece can be finished with high precision using the polishing liquid.

(Example) An example of the present invention will be described below with reference to FIG. The finishing device for a rotating curved surface shown in FIG. 1 includes a box-shaped container 1 with an open top.

At the open end of the container 1, a mounting body 3 having a through hole 2 is provided with its peripheral portion fixed to the upper end of the container 1.

A cylindrical support block 4 is inserted through the through hole 2 . A flange 5 extends outward in the radial direction from the upper end of the support block 4, and the flange 5 is fixed to the mounting body 3 by screws (not shown).

An insertion hole 6 having a circular cross section is bored in the support block 4 along the axial direction. A shaft body 7 whose outer diameter is slightly smaller than that of the insertion hole 6 is rotatably inserted into the insertion hole 6 .

A disk-shaped thrust body 8 is attached to the upper end of this shaft body 7, and a tool 9 is attached to the lower end.

The shaft body 7 is supported by the support block 4 by a non-contact type radial bearing and a thrust bearing, such as a radial air bearing 11 and a thrust air bearing 12. That is, the radial air bearing 11 includes a plurality of upper radial nozzles 13 bored in the upper part of the support block 4 in the axial direction, and a plurality of lower radial nozzles 14 bored in the lower part. Each of the plurality of nozzles 13, 14 has one end opened at the inner peripheral surface of the insertion hole 6, and the other end opened at the outer peripheral surface, and are bored at regular intervals in the circumferential direction.

A plurality of upper discharge holes 15 are provided at predetermined intervals in the circumferential direction at a location between the upper radial nozzle 13 and the lower radial nozzle 14 of the support block 4, and one end thereof is opened to the inner peripheral surface of the insertion hole 6. The other end is opened to the outer peripheral surface. Furthermore, a lower discharge hole 16 is bored in the support block 4 at a location axially lower than the lower radial nozzle 14 . One end of the lower discharge hole 16 communicates with a large diameter portion 6a formed at the lower end of the insertion hole 6.

Compressed air is supplied to each of the radial nozzles 13, 14 from an air source (not shown). The compressed air supplied to each radial nozzle 13, 14 passes between the inner peripheral surface of the insertion hole 6 and the outer peripheral surface of the shaft body 7, and passes through the upper discharge hole 15.
and the lower discharge hole 16. Due to the air flow, the shaft body 7 is supported and positioned in the radial direction without contacting the support block 4.

A plurality of thrust nozzles 17 forming the thrust air bearings 12 are bored in the thickness direction at predetermined intervals in the circumferential direction around the scraper blade of the flange 5. These thrust nozzles 17 have upper ends opened on the upper surface of the flange 5 facing the lower end surface of the thrust body 8, and the lower ends are connected to an air source (not shown). Then, the compressed air jetted from the upper end of the thrust nozzle 17 flows between the upper end surface of the thrust body 8 and the upper end surface of the flange 5.
The shaft body 7 is positioned to be supported by the support block 4 in the thrust direction.

The positioning of the shaft 7 in the thrust direction can be changed by the pressure of the compressed air supplied to the thrust nozzle 17, and if the pressure is varied periodically, the shaft 7 can be vibrated in the thrust direction. be able to.

An inlet passage 18 is bored in the center of the shaft body 7 and the tool 9 so as to communicate with each other. A polishing liquid containing free abrasive grains is supplied to this inflow path 18 from a pump (not shown). The polishing liquid supplied to the inflow path 18 flows out from a plurality of supply holes 19 formed in the tool 9. One end of these supply holes 19 communicates with the inflow path 18, and the other end opens into, for example, a spiral groove 21 formed on the outer peripheral surface of the tool 9. The outer peripheral surface of this tool 9 is a second rotating curved surface 22 provided on a workpiece 22, which will be described later.
It is formed on the first rotating curved surface 9a having a shape corresponding to a.

A workpiece 22 is attached to the lower end surface of the support block 4 concentrically with the support block 4 by means such as a spigot. The workpiece 22 is formed with the above-mentioned second curved surface 22a of revolution, which is an aspherical surface, such as a paraboloid of revolution, an ellipsoid of revolution, or a combination thereof. The second rotating curved surface 22a is precision-cut in advance by diamond cutting to a shape accuracy of sub-μm1 and a surface roughness of about several nanometers. Then, this second rotational curved surface 22
The tool 9 is inserted into the hole a. As a result, the first rotating curved surface 9a of the tool 9 faces the second rotating curved surface 22a of the workpiece 22 with a small distance therebetween, and the polishing liquid flowing out from the supply hole 19 This polishes the second rotating curved surface 22a.

A first magnetic coupling 23 is provided on the outer peripheral surface of the thrust body 8, and a ring-shaped second magnetic coupling is provided on the outer peripheral surface of the first magnetic coupling 23 to be magnetically coupled thereto. 24 are provided spaced apart and facing each other. This second magnetic coupling 2
4 is rotationally driven by a motor 25. Thereby, the tool 9 is interlocked via the first magnetic coupling 23, the thrust body 8, and the shaft body 7.

A disk 26 is formed at the lower end of the tool 9 at the center of rotation with a first rotating curved surface 9a formed on the outer peripheral surface.

This disk 26 is used to check whether the first rotating curved surface 9a is concentric with the second rotating curved surface 22a of the workpiece 22 by using its outer peripheral surface. Furthermore, an outlet 27 is provided in the middle of the side wall of the container 1 in the height direction to discharge polishing liquid when the polishing liquid accumulates in the container 1 at a predetermined level or more.

Next, the operation of the finishing apparatus having the above configuration will be explained. First, after the workpiece 22 is assembled to the support block 4 so as to be precisely concentric, the support block 4 is attached to the mounting body 3 of the container 1.

Next, if the tool 9 is attached precisely and concentrically to the shaft body 7,
While blowing out compressed air from the upper and lower radial nozzles 13 and 14 and the thrust nozzle 17, the shaft body 7 and the tool 9 are
into the insertion hole 6.

The pressure of the compressed air ejected from each of the nozzles 13, 14, and 17 is initially set strong and then gradually lowered. Thereby, the second rotational curved surface 22 of the workpiece 22
The distance between a and the first rotating curved surface 9a of the tool 9 is set to a predetermined state. That is, the tool 9 is positioned and supported on the support block 4 via the shaft body 7 by the radial air bearing 11 and the thrust air bearing 12 in a non-contact state.

After positioning the tool 9 in this manner, the motor 25 is operated to rotate the tool 9, and the polishing liquid is supplied to the inlet passage 18 and flows out from the supply hole 19 of the tool 9. As a result, the abrasive grains contained in the polishing liquid collide with the second rotational surface 22a of the workpiece 22, and the i2 rotational surface 22a is ultra-precision polished on an ordered basis.

In other words, the second rotating surface 22a of the workpiece 22 has two main causes: microelastic fracture caused by the collision of abrasive grains, and interaction on the atomic order between the abrasive grains and the second rotating curved surface 22a. A machining action occurs, as a result of which the second rotating surface 12
2a will be processed to order (surface roughness can be done by 2 to 3 people), and it is possible to obtain ultra-precise surface roughness and shape accuracy, such as with an X-ray microscope, for example.

Further, the tool 9 is supported by the support block 4 in a non-contact manner in the radial direction and the thrust direction by air bearings 11 and 12, respectively. Therefore, the tool 9 is held concentrically with respect to the workpiece 22 with high precision by the radial air bearing 11, and moreover, the thrust air bearing 12 allows the tool 9 to be held concentrically with respect to the workpiece 22. The interval can also be set with high precision. Therefore, these things also make it possible to polish the second rotational curved surface 22a of the workpiece 22 with ultra-precision. Furthermore, if the pressure of the compressed air supplied to the thrust nozzle 17 of the thrust air bearing 12 is periodically varied during the polishing process described above, and the tool 9 is vibrated in the thrust direction, the second rotating curved surface 22a The abrasive action of the abrasive grains increases, and a great polishing effect can be obtained.

Further, the polishing liquid flowing out from the supply hole 19 of the tool 9 rises along the spiral groove 21, flows into between the shaft body 7 and the insertion hole 6, rises, and may flow out to the upper end surface of the support block 4. There is. However, a large diameter portion 6a is formed at the lower end of the insertion hole 6, and the lower radial nozzle 1
The polishing liquid is prevented from rising by the flow of the compressed air supplied to the polishing member 4 and the flow flowing out from the lower discharge hole 16 located below the compressed air.

Note that the present invention is not limited to the above-mentioned embodiment; for example, as shown in FIG. 2, a workpiece 31 is attached to the shaft body 7,
A tool 32 is attached to the lower end surface of the support block 4,
When polishing the second rotational curved surface 31a formed on the outer peripheral surface of the workpiece 31, a spiral groove 33 is formed on the first rotational curved surface 32a of the inner peripheral surface of the tool 32; A supply hole 34 with one end open may be provided. In other words, the rotating curved surface 31a to be polished may be not only the inner circumferential surface but also the outer circumferential surface.

Furthermore, non-contact bearings are not limited to air bearings, but may also be magnetic bearings, and furthermore, the drive means for rotationally driving tools or workpieces is limited to those using magnetic couplings. Of course, it is possible to use other means instead.

Further, the groove formed on the outer peripheral surface or the inner peripheral surface of the tool is not limited to a spiral groove, but may be an annular groove or a straight groove along the axial direction.

[Effects of the Invention] As described above, the present invention positions the first rotating curved surface formed on the tool and the second rotating curved surface formed on the workpiece using a non-contact type radial bearing and a thrust bearing. At the same time, a polishing liquid containing free abrasive grains is supplied to the second rotational curved surface of the workpiece from a supply hole provided in the first rotational curved surface of the tool. Therefore, due to the action of the free abrasive grains, the second part of the workpiece is
It is possible to polish the rotational curved surface of the machine with ultra-precision to order. Moreover, since the tool and workpiece can be positioned concentrically with high precision using non-contact type thrust bearings and radial bearings, polishing accuracy can be improved, and furthermore, the tool or workpiece can be positioned concentrically with high precision. Since the workpiece can be vibrated in the thrust direction, it has the advantage of increasing the polishing action.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the overall configuration of an apparatus showing one embodiment of the present invention, FIG. 2 is a cross-sectional view of a tool and workpiece portion showing another embodiment of the present invention, and FIG. 3 is a conventional This is an explanatory diagram of the technology. 9...Tool, 11...Radial air bearing, 12...
・Thrust air bearing, 13... Upper radial nozzle,
14... Lower radial nozzle, 17... Thrust nozzle, 19... Supply hole, 22... Workpiece, 23.
24...First and second magnetic couplings. Applicant's representative Patent attorney Takehiko Suzue Diagram U.塡゛-1

Claims (2)

[Claims] (1) A first rotational curved surface is formed, this first rotational curved surface is previously formed on the workpiece in a shape close to the first rotational curved surface, and a curved surface equivalent to the first rotational curved surface is formed by free abrasive grains. A tool provided to face a second rotating curved surface formed by machining in a non-contact state, a drive mechanism that rotationally drives the tool or the workpiece, and a second rotating curved surface of the workpiece. A non-contact type radial bearing bearing the first rotating curved surface of the tool for positioning in the radial direction and a non-contact type thrust bearing bearing the positioning bearing in the thrust direction; A finishing device for a rotating curved surface, comprising a supply hole for supplying the polishing liquid containing the free abrasive grains to the second rotating curved surface of the workpiece. (2) The finishing machine for a rotating curved surface according to claim (1), wherein the tool is vibrated in the thrust direction by a thrust bearing.