JP2003011058A - Polishing device and polishing method and manufacturing method for optical part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing device, a polishing method, and a manufacturing method for an optical part capable of improving machining efficiency much more than a conventional method. SOLUTION: This polishing device has a rotary shaft for rotating a polishing tool by itself, a revolving shaft for revolving the polishing tool, and a mobile mechanism for changing a revolving radius of the polishing tool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing apparatus, a polishing method, and an optical component manufacturing method.

[0002]

2. Description of the Related Art Conventionally, in polishing processing, by controlling the residence time of the polishing tool on the processed surface according to the uneven shape of the processed surface, the shape error of the processed surface is corrected to a desired shape. Corrective polishing is being performed to converge the values. In the conventional correction polishing process, the shape component that can be corrected is determined by the size of the outer diameter of the polisher of the polishing tool used.

That is, since the polisher of the polishing tool is generally formed of an elastic body, as shown in FIG. 10A, the outer diameter D1 of the polisher 1 is a shape error component of the machined surface to be corrected. When it becomes larger than half wavelength λ / 2 of
The polisher 1 is elastically deformed following the machined surface, making it difficult to correct the shape of the protrusion 2. Therefore, in order to correct the shape of the protruding portion 2, as shown in FIG.
It is necessary to perform polishing by using a polishing tool whose outer diameter is smaller than the half wavelength λ / 2 of the shape error component of the processing surface to be corrected.

Due to such restrictions, conventionally, the modified polishing method (1) or (2) described below has been performed. (1) A method in which the polishing process is divided into several steps, and the outer diameter of the polisher used in each step is gradually reduced to sequentially correct the shape error component from the low frequency component to the high frequency component.

(2) A method of correcting the shape error components of the low frequency component and the high frequency component at the same time by using a polisher having a small outer diameter from the beginning.

[0006]

However, in the above-mentioned method (1), the waviness component which can be corrected among the shape error components is determined by the outer diameter of the polisher, so that the waviness which is not corrected in one machining is required. There has been a problem that the amount of components increases and the actual work rate decreases.

Further, in the method (1), since there is a great deal of know-how in selecting the outer diameter of the polisher which gives the best polishing efficiency with respect to the shape error, the corrected polishing time is the ability of the operator. There was a problem that the production time was not stable because of the large difference. Furthermore, in the method of (1),
There was a problem that a lot of time was required to replace the polisher.

On the other hand, in the method (2), although the work efficiency is higher than that in the method (1), the work amount becomes small, so that it is often necessary to correct the shape to an aimed value. There was a problem that time was needed. The present invention is
The present invention has been made in order to solve such a conventional problem, and an object thereof is to provide a polishing apparatus, a polishing method, and an optical component manufacturing method capable of significantly improving the processing efficiency as compared with the conventional method.

[0009]

A polishing apparatus according to claim 1,
It is characterized by having a rotation rotating shaft for rotating the polishing tool about its own axis, a revolution rotating shaft for rotating around the polishing tool about the revolution, and a moving mechanism for changing the revolution radius of the polishing tool.
A polishing apparatus according to a second aspect is the polishing apparatus according to the first aspect, wherein the revolution radius is changed corresponding to the polishing position based on the shape error data obtained from the measurement of the work piece, and the revolution radius is changed to the revolution radius. Accordingly, it has a control means for changing at least one of the feed speed of the polishing tool, the rotation speed of the polishing tool, the revolution speed of the polishing tool, and the pressing force of the polishing tool on the workpiece. And

A polishing apparatus according to a third aspect is the polishing apparatus according to the second aspect, wherein the control means determines the revolution radius on the basis of the frequency of the waviness of the workpiece obtained from the shape error data. Is characterized by. The polishing method according to claim 4 polishes a workpiece while rotating and revolving the polishing tool, and the revolution radius of the polishing tool corresponds to a polishing position based on shape error data obtained from measurement of the workpiece. And at the same time, at least one of the feed rate of the polishing tool, the rotation speed of the polishing tool, the rotation speed of the polishing tool, and the pressing force of the polishing tool on the workpiece according to the revolution radius. It is characterized in that the workpiece is polished by changing one of the two.

According to a fifth aspect of the present invention, there is provided a method for producing an optical component by polishing a workpiece by the polishing method according to the fourth aspect.

(Operation) In the polishing apparatus according to the first aspect of the present invention, the moving mechanism changes the distance between the rotation shaft for rotating the polishing tool to rotate and the rotation shaft for rotating the polishing tool to revolve. The revolution radius is changed.

In the polishing apparatus of the second aspect, the control means changes the revolution radius in correspondence with the polishing position based on the shape error data obtained from the measurement of the workpiece. And at the same time, depending on the revolution radius, the feed rate of the polishing tool,
At least one of the rotation speed of the polishing tool, the revolution speed of the polishing tool, and the pressing force of the polishing tool on the workpiece is changed.

In the polishing apparatus of the third aspect, the control means determines the revolution radius based on the frequency of the waviness of the workpiece obtained from the shape error data. In the polishing method according to the fourth aspect, the revolution radius is changed corresponding to the polishing position based on the shape error data obtained from the measurement of the workpiece. At the same time, at least one of the feed rate of the polishing tool, the rotation speed of the polishing tool, the revolution speed of the polishing tool, and the pressing force of the polishing tool on the workpiece, depending on the radius of revolution.
One is changed.

In the optical component manufacturing method of the fifth aspect, the workpiece is polished by the polishing method of the fourth aspect to manufacture an optical component such as a lens.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of a polishing apparatus of the present invention, and reference numeral 11 denotes a polishing tool made of polisher. The polishing tool 11 is rotatable about a rotation axis 13 of rotation. A revolving rotary member 15 is arranged above the polishing tool 11, and a revolving rotary shaft 17 for revolving the polishing tool 11 is arranged at one end of the revolving rotary member 15.

The revolution rotating shaft 17 is formed in parallel with the rotation rotating shaft 13. On the upper surface of the revolution member 15,
Revolution radius R of polishing tool 11, that is, rotation axis 13
A moving mechanism 19 that changes the distance between the revolving rotary shaft 17 and the orbiting rotary shaft 17 is arranged. In this embodiment, the moving mechanism 19 is
The rotation axis 13 is moved in the direction approaching the revolution axis 17 or in the opposite direction to change the revolution radius R of the polishing tool 11.

That is, an elongated hole (not shown) is formed in the revolving rotary member 15 along the moving direction of the moving mechanism 19, and the rotation shaft 13 is inserted through the elongated hole. The rotation shaft 13 is supported by the revolving rotation member 15 by a bearing (not shown) so as to be movable along the elongated hole. Then, by driving the moving mechanism 19, the rotation shaft 13 is moved along the elongated hole.

On the upper surface of the moving mechanism 19, the rotation shaft 13
A rotation motor 21 for rotating the motor is arranged.
A revolution motor 25 for rotating the revolution rotating shaft 17 is provided on the upper surface of the revolution rotating shaft 17 via an air cylinder 23.
Are arranged. In FIG. 1A, the chain double-dashed line indicates the rotation shaft 13 when the polishing tool is rotated about the revolution rotation shaft 17, and the diagonal line in FIG. 1B indicates the unit of the polishing tool. The removal shape K is shown.

In FIG. 1, reference numeral 27 indicates a controller for controlling the polishing apparatus of this embodiment. The control device 27 changes the revolution radius R corresponding to the polishing position based on the shape error data obtained from the measurement of the workpiece,
At the same time, the optimum correction polishing process is performed by changing the feed rate of the polishing tool 11 according to the revolution radius R.

That is, in the present invention, the revolution radius R, which is the distance between the rotation shaft 13 and the revolution shaft 17, and the unit removal shape K when the polishing tool 11 having the revolution radius R is used in advance.
2 is obtained, and a correlation diagram as shown in FIG. 2 is obtained. As shown in FIG. 1B, the size D of the unit removal shape K is the outer diameter of the polishing tool 11 that contacts the processing surface 29 during polishing, and the polishing load P that is the pressing force against the workpiece. Depends on the size of.

That is, as the polishing load P increases, the elastic deformation of the polishing tool 11 increases the outer diameter in contact with the machined surface. In FIG. 2, the polishing load P is P4.
<P3 <P2 <P1. Further, the relationship between the depth E of the unit removal shape K and the processing time is obtained, and the correlation diagram as shown in FIG. 3 is obtained.

The depth E of the unit removal shape K is shown in FIG.
As shown in, the depth E is removed by the polishing tool 11 during polishing, while it becomes shallower as the size D of the unit removal shape K increases, and becomes deeper as the size P of polishing increases. . Therefore, in FIG. 3, a plurality of correlation diagrams are created according to the magnitude of the polishing load P. Further, each correlation diagram shows the sizes a, b, c, of the unit removal shape K shown in FIG.
It is created corresponding to d.

In FIG. 3, the polishing loads are P1, P
Only the correlation diagram for 2 and P3 is shown. Next, on the basis of the shape error data obtained from the measurement of the workpiece, for example, the filtering process is performed for each desired undulation period band shown by in FIG. 4, and as shown in FIG. At each position of the processed surface of the work piece, a correlation diagram is obtained which corresponds to which of the periodic bands of the undulation that is most quantitatively controlled corresponds to.

Further, as shown in FIG. 5 (b), the error amount G at each position on the machined surface of the workpiece is obtained. In addition, in this embodiment, since the pre-machined surface is machined by the machining mode of the rotary motion, the correlation diagram becomes a distribution diagram in an annular band shape. In addition, at the boundary between the adjacent annular zones, as shown by the diagonal lines in FIG. 6, 1/3 to 1/5 of the width W of each annular zone is set as the boundary, and the annular zones adjacent to each other are obtained. The boundary is machined under an intermediate condition of the machining conditions.

In this way, the processing for forming a continuous shape is performed by connecting the processing conditions at the boundary. Then, in this embodiment, as shown by a thick line in FIG. 7, the polishing tool 11 is rotated without rotating the workpiece.
The polishing process is performed by moving right and left. Next, at the time of processing the work piece, the computer calculates the revolution radius R and the residence time of the polishing tool 11 at each polishing position.

That is, first, the revolution radius R at each position is determined based on FIG. 2 in accordance with the periodic band distribution information of the correlation diagram of FIG. At this time, as shown in FIG. 8, the revolution radius R is determined from FIG. 2 so that the size D of the unit removal shape K becomes the size of T / 2 of the undulation period T dominant at each position. , Which allows the most efficient removal.

Next, from the information of the error amount G at each position of the processed surface of the workpiece shown in FIG. 5B and the correlation diagram of FIG. 3, the processing time of the polishing tool 11 at each position is shown. It is calculated.

Then, based on this processing time (residence time), the polishing tool 11 at each position on the processing surface of the workpiece is processed.
Is determined, an NC program for correction polishing is created, and polishing is performed based on this NC program. In the above-mentioned polishing apparatus, by changing the revolution radius R of the polishing tool 11 by the moving mechanism 19,
It is possible to obtain substantially the same effect as changing the outer diameter of the polishing tool 11 without replacing the polishing tool 11.

Therefore, by changing the revolution radius R of the polishing tool 11 in accordance with the shape error of the workpiece, the working efficiency can be greatly improved as compared with the conventional case. In addition,
More specifically, the revolution radius R is 0 to the radius of the polishing tool 11 or less, and when the revolution radius R is 0, the same function as that of the conventional polishing tool 11 is achieved. Further, when the revolution radius R is the radius of the polishing tool 11, 2 of the conventional polishing tool 11 is used.
Works as double diameter.

In the above-described polishing apparatus and polishing method, the controller 27 changes the revolution radius R corresponding to the polishing position based on the shape error data obtained from the measurement of the workpiece, and at the same time, rotates the revolution. Since the feed rate of the polishing tool 11 is changed according to the radius R, the working efficiency can be significantly improved without largely depending on the ability of the operator.

Further, in the above-mentioned polishing apparatus, since the revolution radius R is determined based on the frequency of the undulation of the work piece obtained from the shape error data, the undulation can be removed efficiently. Further, by using the above-described polishing method to polish an optical member such as a lens, an optical component such as a lens can be efficiently manufactured with high accuracy.

In the above embodiment, the revolution radius R
According to the above, an example in which the optimum correction polishing processing is performed by changing the feed rate of the polishing tool 11 has been described, but the present invention is not limited to such an embodiment, and according to the revolution radius R, The rotation speed of the polishing tool 11,
Optimal correction polishing may be performed by changing the revolution speed of the polishing tool 11 or the pressing force of the polishing tool 11 against the workpiece.

Further, according to the revolution radius R, the polishing tool 11
Feed rate, rotation speed of polishing tool 11, polishing tool 11
The optimum correction polishing may be performed by changing at least two of the revolution speed and the pressing force of the polishing tool 11 against the workpiece.

[0036]

As described above, in the polishing apparatus according to the first aspect, the outer diameter of the polishing tool is changed without changing the polishing tool by changing the revolution radius of the polishing tool by the moving mechanism. It is possible to obtain substantially the same effect as.

Therefore, by changing the revolution radius of the polishing tool in accordance with the shape error of the workpiece, the machining efficiency can be greatly improved as compared with the conventional case. In the polishing apparatus according to claim 2, the control means changes the revolution radius corresponding to the polishing position based on the shape error data obtained from the measurement of the workpiece, and at the same time, changes the radius of revolution of the polishing tool according to the revolution radius. Since at least one of the feed rate, the rotation speed of the polishing tool, the revolution speed of the polishing tool, and the pressing force of the polishing tool on the workpiece is changed, the processing efficiency does not largely depend on the ability of the operator. Can be improved significantly.

According to the polishing apparatus of the third aspect, the revolution radius is determined based on the frequency of the undulation of the work piece obtained from the shape error data, so that the undulation can be efficiently removed. According to the polishing method of claim 4, the revolution radius is changed corresponding to the polishing position based on the shape error data obtained from the measurement of the workpiece, and at the same time, the feed rate of the polishing tool and the polishing are changed according to the revolution radius. Rotation speed of the tool,
Since at least one of the revolution speed of the polishing tool and the pressing force of the polishing tool with respect to the workpiece is changed, the processing efficiency can be significantly improved without largely depending on the ability of the operator.

In the method of manufacturing an optical component according to the fifth aspect, an optical component such as a lens can be efficiently manufactured with high accuracy.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a polishing apparatus of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a revolution radius of the polishing apparatus of FIG. 1 and a size of a unit removal shape.

FIG. 3 is an explanatory diagram showing a relationship between a depth of a unit removal shape and a processing time.

FIG. 4 is an explanatory diagram showing divisions of a periodic band on a processed surface of a workpiece.

FIG. 5 is an explanatory diagram showing a distribution of a periodic band on a processed surface of a workpiece and an error amount.

FIG. 6 is an explanatory diagram showing a boundary of an annular zone.

FIG. 7 is an explanatory diagram showing a method for polishing the processed surface of the workpiece shown in FIG.

8 is an explanatory diagram showing a method of setting a revolution radius of the polishing apparatus of FIG.

FIG. 9 is an explanatory diagram showing a method of setting a residence time of a polishing tool.

FIG. 10 is an explanatory diagram showing a relationship between a diameter of a polishing tool and a wavelength.

[Explanation of symbols]

11 Polishing tool 13 rotation axis 17 revolution axis 19 Moving mechanism 27 Control device R revolution radius

Claims (5)

[Claims] 1. A polishing apparatus comprising: a rotation shaft for rotating a polishing tool around its axis; a revolution shaft for rotating around the polishing tool about an axis; and a moving mechanism for changing a revolution radius of the polishing tool. . 2. The polishing apparatus according to claim 1, wherein the revolution radius is changed corresponding to the polishing position based on the shape error data obtained from the measurement of the workpiece, and the revolution radius is changed according to the revolution radius. The feed rate of the polishing tool,
A polishing apparatus comprising: a control unit that changes at least one of the rotation speed of the polishing tool, the revolution speed of the polishing tool, and the pressing force of the polishing tool on the workpiece. 3. The polishing apparatus according to claim 2, wherein the control means determines the revolution radius based on the frequency of the waviness of the workpiece obtained from the shape error data. . 4. The work piece is polished while rotating and revolving the polishing tool, and the revolution radius of the polishing tool is changed corresponding to the polishing position based on the shape error data obtained from the measurement of the work piece. At the same time, at least one of the feed rate of the polishing tool, the rotation speed of the polishing tool, the revolution speed of the polishing tool, and the pressing force of the polishing tool on the workpiece is changed according to the revolution radius. And a method of polishing the object to be processed. 5. A method for manufacturing an optical component, which comprises polishing an object to be processed by the polishing method according to claim 4 to manufacture an optical component.