JPH04193469A - Method and device for polishing - Google Patents

Abstract

PURPOSE:To execute polishing in an atomic order, by feeding a work liquid continuously from the liquid hole of a polishing tool. CONSTITUTION:A work 1 is polished by flowing a work liquid A mixed with fine polishing particles between the work 1 and a polishing tool 3. In this case, the liquid layer of the work liquid A is formed between the work 1 and polishing tool 3, by continuously feeding the work liquid A from the liquid hole 9 of the polishing tool 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and an apparatus for polishing a workpiece such as an optical element by flowing a working fluid therethrough.

[Conventional technology]

As a means of polishing optical elements such as glass lenses, a submerged polishing method is known in which a workpiece is polished in a polishing solution (see Utility Model Application Publication No. 55-41295 and "Crystal Processing and Surface J (1970) (Published by the Physical Society of Japan on November 30th, pp. 154-156). Figure 7 shows the device used for this submerged polishing. A plate 72 is attached to a knife 74 connected to a swinging mechanism 73. A polishing tool 75 for polishing is supported by a rotating shaft 76, and its polishing surface 75a is in contact with the lower surface of the workpiece 71.

Further, the rotating shaft 76 is provided with a liquid tank 78 filled with polishing liquid 77.
A workpiece 71 and a polishing tool 75 are immersed in this polishing liquid 77.

In such a configuration, the polishing tool 7 is rotated by the rotating shaft 76.
At the same time, the swing mechanism 73 rotates the kanzashi 7.
When the workpiece 71 is rotated by swinging the workpiece 71, the workpiece 7I is polished by the polishing liquid 77, so that it is possible to process a smooth surface with a surface roughness equivalent to that of several dozen workers.

Such submerged polishing requires only a few dozen people to process the surface roughness, and it is only possible to process the surface roughness of 10 Å or less. For this reason, EEM (
Elastic Emission Machine
ing) method has been developed. Figure 8 shows the literature “Ultimate machining of atomic order without altered layer J (NIKKEI M
This section describes the principles of the EEM method introduced in ECHANTCAL, published January 4, 1982). A machining liquid 82 in which fine abrasive particles 81 are suspended in pure water is brought into contact with the surface to be ground of a workpiece 83, and a rotating ball 84 made of polyurethane is immersed in the machining liquid 82. Then, by rotating the rotating ball 84 in the machining fluid 82 to generate a flow in the machining fluid 82, the abrasive particles 81 collide with the surface to be ground of the workpiece 83, thereby breaking atomic bonds by elastic shearing and polishing. This polishing makes it possible for several people to perform processing on the order of atoms.

FIG. 9 shows a conventional polishing apparatus which applies the principle of the 20EE-1 method and is described in the above-mentioned document. This polishing device processes a workpiece 83 while floating it above a ramp surface 85 of an opposing polishing tool.
A workpiece 83 is held on the lower surface of a holding member 86 that rotates, and a wrap surface 85 facing the workpiece 83 is connected to a rotating shaft 87.

Then, these works 83 and the lap surface 85 or the liquid tank 8
8 is immersed in machining liquid 82. A machining fluid 82 is always present between the workpiece 83 and the lapped surface 85 due to a fluid bearing action, and when the holding member 86 and the rotating shaft 87 are rotated to relatively rotate the workpiece 83 and the lapped surface, the machining fluid 82 or these fluids are interposed between the workpiece 83 and the lapped surface 85. It flows between. This flow causes the fine abrasive particles 81 in the machining liquid 82 to collide with the workpiece 83, so that machining on the atomic order is performed, making it possible to machine a flat surface with high precision and quality.

[Invention or problem to be solved]

However, in the conventional polishing apparatus, polishing is performed by forcibly flowing the machining liquid 82 filled in the liquid tank 88 between the workpiece 83 and the rack surface 85. Work 8 against lap surface 85
It was necessary to accurately control the parallelism of the surface to be ground No. 3 and the gap between the lap surface 85 and the workpiece 83 to ensure good flow of the machining fluid. In particular, when machining a workpiece into a spherical surface, it is necessary to further improve the accuracy described above, resulting in a complicated structure and difficult control.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a polishing method that enables EP polishing with simple control and structure, and a polishing method that can be applied to the method.

[Means to solve the problem]

In order to achieve the above object, in the polishing method of the present invention (a method of polishing a workpiece by flowing a machining liquid mixed with fine abrasive particles between the workpiece and a polishing tool, The machining fluid was continuously supplied through the hole to form a liquid layer between the workpiece and the polishing tool.

In addition, the polishing apparatus of the present invention for carrying out this polishing method includes a polishing tool that has a hole for the machining fluid to flow out on the machining surface facing the workpiece, and a polishing tool that uses the machining fluid mixed with fine abrasive particles. a workpiece holding member having a force for holding the workpiece and covering the machining surface to form a liquid layer of machining liquid between the workpiece and the machining surface; A means for relatively rotating the polishing tool and the workpiece holding member to cause the machining fluid to flow is provided.

FIG. 1 shows the basic configuration of the polishing apparatus of the present invention, in which a workpiece 1
The polishing tool 3 has a workpiece holding member 2 that holds the workpiece 1, and a polishing tool 3 that faces the workpiece 1 with a gap l of a predetermined size. The work holding member 2 includes a holder 4 into which the work 1 is fitted and pasted, and a handle 5 to which the holder 4 is attached.The handle 5 is connected to a swinging mechanism (not shown), and the holder 4 holds the work 1. It swings while being held. This holder 4 has a cover part 6 that extends outward from the part holding the work l. The cover portion 6 is formed so that its lower surface is flush with the lower surface of the workpiece 1.

The polishing tool 3 is attached to the rotating shaft 7 and rotates integrally with the rotating shaft 7. This polishing tool 3 has a processing surface 8 that faces the workpiece 1, and a plurality of liquid holes 9 are formed in this processing surface 8.
or is formed through. Further, a liquid chamber 10 communicating with the liquid hole 9 is formed inside the polishing tool 3, and a flow path 11 communicating with the liquid chamber 1O is formed inside the rotary shaft 7. The flow path 11 of the rotating shaft 7 is connected to a pump (not shown) via a rotary joint (not shown), and the flow path 11 is connected to a pump (not shown) by driving the pump.
The machining fluid A is supplied into the fluid chamber 10 from the fluid hole 9, and the machining fluid A continuously flows out from the fluid hole 9. Therefore, the pump, rotating shaft 7
The flow path 11 and the liquid chamber 10 of the polishing tool 3 constitute means for continuously supplying the machining liquid.

On the other hand, the rotating shaft 7 is connected to the polishing tool 3 relative to the workpiece holding member 2.
This is a means for applying fluidity to the machining fluid flowing out from the fluid hole 9 by rotating the fluid holes 9 relative to each other.

In this case, the cover portion 6 of the workpiece holding member 2 is attached to the polishing tool 3.
is provided so as to cover the liquid hole formation site, thereby holding the person between the work l and the machining surface 8 of the polishing tool 3 after machining. Further, the processing liquid A is supplied with fine abrasive particles suspended therein.

[Function] - When the machining fluid A is continuously supplied from the rotary shaft 7, the machining fluid either flows out from the fluid hole 9 on the machining surface 8 or is covered by the cover part 9, so there is no pressure loss or a liquid layer. In this state, the gap between the polishing tool 3 and the workpiece holding member 2 is filled. As a result, the workpiece 1 and the workpiece holding member 2 are placed in a floating state due to the hydraulic pressure of the machining fluid A. In this state, when the rotary shaft 7 is rotated and the cover 4 is swung, the polishing tool 3 and the workpiece holding member 2 rotate relative to each other, and this relative rotation accelerates the flow of the machining fluid, causing abrasive particles in the machining fluid. or collides with the surface of the workpiece l. Therefore, it is possible to perform a polishing process on the atomic order on the workpiece 1 using the EEM method. During this machining, the machining fluid is continuously supplied from the liquid hole 9 of the polishing tool 3, and fluidity is imparted by the relative rotation between the workpiece holding member 2 and the polishing tool 3, so that reliable polishing is possible. , control becomes easier.

〔Example〕

Hereinafter, the present invention will be specifically explained based on Examples. In each embodiment, the same elements as in FIG. 1 are denoted by the same reference numerals and correspond to each other.

(First Embodiment) FIG. 2 shows a first embodiment of the present invention, in which liquid holes 9 are formed on the machined surface 8.
The polishing tool 3, which has been formed with a polishing tool 3, is rotatably inserted into the processing tank 21. The rotating shaft 7 for rotating the polishing tool 3 supports a machining tank 21, or a gasket 22 is provided between it and the machining tank 21 to maintain watertightness. The flow path 11 of the rotary shaft 7 communicates with the liquid chamber lO of the polishing tool 3, and after the machining liquid A supplied to the rotary shaft 7 fills the liquid chamber lO, it passes through the liquid hole 9 to the polishing tool 3 and the workpiece. It flows out between the holding member 2 and the holding member 2. In addition, as the processed material, for example, fine powder particles such as Noriyoku suspended in pure water can be used.

The upper surface of the processing tank 21 is open, and the processing tank 21
It is housed in a receiving tank 22 that has a larger diameter and is nobler than the original one. The receiving tank 22 receives and collects the machining fluid A overflowing due to the centrifugal force caused by the rotation of the machining tank 21, and has a discharge port 23 formed at the bottom for collection. The rotating shaft 7 passes through this receiving tank 22, or a bearing portion 24 of the rotating shaft 7 is formed in a cylindrical shape at the penetrating portion. And this bearing part 24
A watertight hood 25 covering the rotary shaft 7 is attached to the rotary shaft 7.

The workpiece holding member 2 is provided so that a cover portion 6 having a diameter that covers the machining surface 8 of the polishing tool 3 is flush with the workpiece l, and this cover portion 6 provides a space between the workpiece holding member 2 and the polishing tool 3. Processing fluid A is held in a liquid layer state. The holder 4 in this work holding member 2 is swung by a cover 5.

In this embodiment having such a configuration, when machining liquid is continuously supplied from the rotary shaft 7 to the liquid chamber lO of the polishing tool 3 by driving a pump (not shown), the machining liquid A flows into the liquid hole of the polishing tool 3. 9
flows out from The cover portion 6 of the workpiece holding member 2 fills the space between the workpiece holding member 2 and the polishing tool 3 in a liquid layer state with little pressure loss, so that the workpiece l and the workpiece holding member 2 are placed in a floating state. At this time, when the rotary shaft 7 is rotated and the cover 5 is swung, the polishing tool 3 and the workpiece holding member 2 rotate relative to each other, and fluidity is imparted to the machining fluid.
Collision with the atomic order polishing process is performed, resulting in high precision,
Able to perform high quality polishing. On the other hand, the machining fluid A that has flowed out between the work l and the polishing tool 3 overflows into the receiving tank 22 from the upper opening of the processing tank 21 and is recovered from the discharge port 23 of the receiving tank 22 . Therefore, the collected machining fluid can be reused.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention. In this second embodiment, a work l is processed into a spherical surface, and the processing surface 8 of the polishing tool 3 is formed into a predetermined spherical shape. Further, the rotating shaft 7 for rotating the polishing tool 3 has a spherical center θ of the polishing tool 3,
It is capable of swinging around the center of rotation, and swings within an angular range preset by a swing transmission mechanism (not shown).

On the other hand, the cover portion 6 of the workpiece holding member 2 facing the machining surface 8 is formed into a spherical surface with a curvature between the lower surface and the grinding surface of the workpiece 1, and has a swinging range due to the swinging of the rotating shaft 7. It has a diameter that covers the

In this embodiment, by continuously supplying machining liquid and relative rotation of the polishing tool 3 and the workpiece holding member 2, it is possible to perform polishing on the atomic order on the workpiece l, or to polish the workpiece to a spherical surface. It has the advantage of being easily processed. Therefore, it is possible to perform spherical processing with a simple configuration and easy control.

(Third Embodiment) FIGS. 4 and 5 show a third embodiment of the present invention. In this third embodiment, similarly to the second embodiment, the workpiece I is machined into a spherical surface, and the cover portion 6 of the workpiece holding member 2 is formed into a spherical surface with a curvature between the ground surface of the workpiece I and the groove. At the same time, the processing surface 8 of the polishing tool 3 is formed into a spherical shape. In this embodiment, the cover part 6 is formed to have a small diameter, and an auxiliary cover 31 to compensate for the insufficient size of the cover part 6 is attached to the workpiece holding member 2.

The lower surface of the auxiliary cover 31 is a spherical surface with a curvature similar to that of the cover part 6, and the entire auxiliary cover 31 has an arcuate shape along the outer peripheral surface of the cover part 6, as shown in FIG. Further, this auxiliary cover 31 is attached to an arm 32 that is rotatably connected to the cover 5, and as the arm 32 rotates, it moves to any position on the outer circumferential surface of the cover part 6 and becomes integral with the cover part 6. This acts to hold the machining fluid A between the workpiece holding member 2 and the polishing tool 3. As a result, atomic-order spherical surface machining can be performed using the machining fluid. In particular, in this embodiment, the cover portion 2 of the workpiece holding member 2
Since the liquid hole 9 of the polishing tool 3 removed from the polishing tool 3 can be covered with the auxiliary cover 31, the cover portion 6 of the workpiece holding member 2 can be made small enough to cover the vicinity of the outer periphery of the workpiece 1. Therefore, the work holding member 2 can be made small Y.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention. In this fourth embodiment, the cover 5 is connected to a motor (not shown) and is driven to rotate, and as the cover 5 rotates, the work holding member 2 also rotates in accordance with the rotation of the cover 5. That is,
A driven pin 41 is provided upright on the holder 4 of the work holding member 2, and an operating pin 42 that is orthogonal to the driven pin 41 is provided on the cover 5. In this configuration, when the motor 5 rotates, the operating bin 42 comes into contact with the follower 41, so the holder 4 follows and rotates, and the workpiece 1 held by the holder 4 also rotates.

This rotation of the workpiece 1 is performed during machining with the machining fluid, and as the workpiece 1 rotates, the collision between the abrasive particles in the machining fluid and the surface of the workpiece 1 is further promoted and becomes active. , machining time can be shortened.

In addition, since the workpiece 1 rotates around the 0° spherical center of the holder 4, even if the curvature of the cover part 6 is different by dP from the curvature R of the workpiece 1, these spherical centers coincide with the spherical center 02. By doing so, spherical surface machining can be reliably performed. Therefore, the material of the holder 4 can be molded from metal, ceramics, plastic, etc., and the degree of freedom in material selection is increased.

〔Effect of the invention〕

As explained above, according to the present invention, since the machining fluid is continuously supplied from the fluid hole of the polishing tool, polishing on the atomic order can be performed with a simple configuration and control.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic configuration of the polishing apparatus of the present invention, FIG. 2 is a sectional view showing the first embodiment of the present invention, and FIG.
4 and 5 are sectional views showing the third embodiment, FIG. 6 is a sectional view showing the fourth embodiment, and FIG. 7 is a submerged polishing apparatus. 8 is a side view illustrating the principle of the EEM method, and FIG. 9 is a sectional view showing a conventional polishing apparatus using the EEM method. ■ Work 2 Work holding member 3 Polishing tool 6 Cover part 7 Rotating shaft 8 Machining surface 9 Liquid hole 31 Auxiliary cover Patent applicant Olympus Optical Industry Co., Ltd. Fig. 1 1 Work 2 Work holding member 3 Polishing tool 6 Cover part 7 Rotating shaft 8 Processing surface 9 Liquid hole 31 ...Auxiliary capacitor - Figure 4, Figure 5, Figure 7, Figure 8

Claims (2)

[Claims] (1) In a method of polishing a workpiece by flowing a machining fluid mixed with fine abrasive particles between the workpiece and a polishing tool, the machining fluid is continuously supplied from the fluid hole of the polishing tool, and the workpiece is A polishing method characterized by forming a liquid layer of machining fluid between a polishing tool and a polishing tool. (2) A polishing tool having a liquid hole through which the machining fluid flows out on the machining surface facing the workpiece, a means for continuously supplying the machining fluid mixed with fine abrasive particles to the polishing tool, and a workpiece held. At the same time, a workpiece holding member having a cover portion that covers the processing surface to form a liquid layer of processing liquid between the workpiece and the processing surface, and the polishing tool and the workpiece holding member are relatively rotated to form a liquid layer of processing liquid. A polishing device characterized by comprising: means for generating a flow in the polishing device.