JPH0635101B2 - Method for simultaneously processing three surfaces and apparatus used for the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an optical element such as a lens used in an optical device such as a camera, a metal die for a lens press, and the like having two predetermined shapes. The present invention relates to a method for simultaneously processing three surfaces of an upper surface, a lower surface and a peripheral wall, which can be suitably used for manufacturing various members having a disk or a columnar portion having opposing surfaces, and an apparatus used for the method, for example, in a lens structure. The present invention relates to a method for simultaneously processing three surfaces suitable for simultaneously performing a finishing process and a centering process for a pair of opposing lens surfaces, and an apparatus used for the method.

[Conventional technology]

For example, in an optical element such as a lens used in an optical device such as a camera, a material preliminarily processed into a predetermined shape made of glass or the like is subjected to finishing processing such as polishing and grinding separately for each surface, and both surfaces facing each other are subjected to predetermined processing. After finishing as a lens surface,
It has been conventionally manufactured by a method including a step of performing centering.

However, in such a conventional method, at least two processing devices dedicated to single-sided processing and a centering processing device are required, and a large number of devices are required for large-scale processing, and moreover, they are required. Takes up a lot of space. In addition, the time required for the working process becomes very long.

On the other hand, Japanese Patent Application Laid-Open No. 57-102747 discloses a device for simultaneously processing a pair of lens surfaces, which allows the number of lens surface processing devices to be halved. After finishing the lens surface, it is still necessary to perform additional centering.

On the other hand, centering is a process in which the lens to be processed is centered by the so-called bell clamp hold through the lens surface that is usually finished by a clamp made of metal, etc. This is done by symmetrically processing the peripheral wall of the lens, but special consideration must always be taken so that the lens surface is not damaged by the clamp.

[Problems to be solved by the invention]

The present invention has been made in view of the above-described conventional techniques, and an object thereof is to provide two facing elements such as a pair of lens surfaces of an optical element such as a lens or a workpiece to be processed into a similar shape. The present invention provides a three-sided simultaneous processing method and a device used for the method, which can simultaneously perform the simultaneous processing of the surface to be processed and the processing of the peripheral wall such as the centering processing in the lens, and further solve the above-mentioned problems in the prior art. It is to solve effectively.

[Means for solving problems]

That is, according to the present invention, the two peripheral surfaces having different peripheral velocities are contacted with each other of the two surface-to-be-processed of the workpiece having a surface shape corresponding to the surface to be formed, respectively, and are pressed in the directions of pressing each other. A process of maintaining the sandwiched state of the workpiece between a pair of machining tool surfaces that press the workpiece, and simultaneously machining the two opposed workpiece surfaces; sandwiched between the tool surfaces,
A three-sided simultaneous machining method, characterized in that it includes a process of machining a peripheral wall of a workpiece in a rotating state symmetrically with respect to the rotation center axis, and a peripheral speed different from each other, each of which is formed. 2 to face the work piece with a surface shape corresponding to the surface to be processed
To form a pair of processing tool surfaces that contact each of the two processing surfaces and press the workpiece in the direction of pressing each other, so that the state of clamping the processing object between these processing tool surfaces can be maintained. A pair of surface processing tools provided; abutting against the peripheral wall of the workpiece sandwiched between the processing tool surfaces, and utilizing the rotation of the workpiece, the peripheral wall around the rotation center axis And a peripheral wall machining tool capable of symmetrically machining.

The tool for surface processing in the present invention is a tool for contacting a surface to be processed with a predetermined surface shape and sliding the surface to process the surface into a predetermined surface shape. The surface refers to the surface portion of the tool that is in contact with the surface to be processed during processing.

Examples of the surface processing tool used in the present invention include various surface processing tools such as polishing and grinding. The surface to be processed (processed surface) has a desired shape surface accuracy and surface roughness. Those having a configuration capable of forming the processing tool surface necessary for imparting the are appropriately used.

A machining method of the present invention and an apparatus used for the method maintain a sandwiching state between a pair of opposing two surfaces of a workpiece between machining tool surfaces formed by such a surface machining tool, These surfaces are simultaneously processed.

Further, the peripheral speeds of these machining tool surfaces are set to be different from each other, and as a result, the workpiece clamped between the machining tool surfaces rotates, and the peripheral wall machining tool contacts the peripheral wall of the rotating workpiece. Contacted. Therefore, the pair of surface processing tools are used in a combination having a structure in which there is a sufficient difference in the peripheral speeds of the processing tool surfaces to rotate the workpiece due to its configuration or operation. .

[Action]

On the pair of facing work surfaces of the work piece, the working tool surfaces formed by the surface working tool are simultaneously pressed,
Each of them is simultaneously processed into a desired processing state such as shape surface accuracy and surface roughness.

Further, the work piece rotates by being sandwiched between the processing tool surfaces having different peripheral speeds, the peripheral wall of the rotating work piece is brought into contact with the peripheral wall processing tool, and the peripheral wall of the work piece is
It is processed symmetrically with respect to the rotation center axis.

Further, when a member having a pair of opposed surfaces, one of which is a spherical surface, is sandwiched between two surfaces having surface shapes corresponding to these surfaces and having different peripheral speeds, a spherical core of a spherical surface that coincides with the pressing direction of the sandwiched surface is formed. By utilizing the phenomenon that a member can be rotated about an axis passing therethrough, by making at least one of the machining tool surfaces of the present invention spherical, the machining tool surface along the pressing direction against the workpiece The workpiece can be rotated around an axis passing through the spherical core.

For example, in the case of processing an optical element such as a lens, one of a pair of processing tool surfaces is a spherical surface and the other is a flat surface, and the surfaces are two opposing mechanical surfaces of a workpiece in a direction in which these processing tool surfaces are pressed against each other. If pressed against the (working surface), the work piece rotates about an axis that coincides with the pressing direction, that is, passes through the spherical core of the spherical machining tool surface and the axis perpendicular to the planar machining tool surface, Moreover, the rotation center axis automatically coincides with the common optical axis of the flat surface and the spherical surface, and if the peripheral wall of the work piece is processed symmetrically with respect to this rotation center axis, the work piece can be centered. Further, if both the pair of machining tool surfaces are spherical surfaces and these machining tool surfaces are pressed against each other in a direction of pressing each other, an axis that coincides with the pressing direction, that is, a sphere of two spherical machining tool surfaces. The work piece rotates about an axis passing through the core, and its rotation center axis automatically coincides with the common optical axis of the spherical surface, and the peripheral wall of the work piece can be machined symmetrically with respect to this rotation center axis. For example, the work can be centered.

〔Example〕

First, an embodiment of an apparatus for simultaneous processing of three surfaces of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic vertical sectional view showing the structure of a precise grinding processing device of the present invention when performing fine grinding (metal pellet) processing on a biconcave spherical lens, and FIG. 2 is a diagram showing main components of the device. It is the schematic which showed the positional relationship.

The tools for lens surface processing in this device are the plates 2a and 2b.
The concave spherical fine grinding tools (metal pellets) 3a, 3b attached in a spherical band shape with the axes 0 ₁ , 0 ₂ as the central axes at predetermined positions on the surface of the hemispherical portion of the table 2a, 2b. , Axes 0 ₁ , 0 ₂
A pair of concave spherical surfaces having predetermined radii of curvature r ₁ and r ₂ to be given to the lens surface by being rotated in the directions of arrows n ₁ and n ₂ by a rotation mechanism (not shown) about Are provided so that the machining tool surfaces 7a and 7b for the can be formed. The processing tool surfaces 7a and 7b are contact surfaces with the lens to be processed when the pedestals 2a and 2b are rotating, and the axes passing through the respective spherical cores (centers of curvature) R ₁ and R ₂ are coaxial (
0 ₅ ).

Furthermore, the Thai sala 2b provided with the tool 3b, the pressing processing mechanism (not shown) is connected at a desired pressure P with respect to the subject lens 1 a machining tool surface 7b in the axial 0 ₅ direction . In this device, the pressing force P can be adjusted in two steps.

In this example, the base 2a is fixed, and the base 2b is pressed by the pressing mechanism, and the pressing of the lenses to be processed in the mutually pressing directions by the processing tool surfaces is realized. dish
2b may be fixed and pressed by the pedestal 2a, or both of them may be connected to a pressure mechanism and pressed by both.

Furthermore, Thai sala 2a, the 2b, the tool 3a, the rotation center axis 0 ₁ of 3b,
0 ₂ the machining tool surface of 7a, the center of curvature R _1, R ₂ about the turning mechanism for turning each of 7b (not shown), the centers of curvature R _1, R ₂ around the tool 3a, 3b of the rotational center axis 0 ₁ , 0 ₂
Is connected to a swinging mechanism (not shown) that swings a small width in a direction indicated by arrows A ₁ and A ₂ .

The widths of the tools 3a, 3b provided in the shape of a spherical belt have a center of curvature R ₁ ,
R ₂ around the die plates 2a, when a 2b is swung by the arrow A _1, A ₂ direction, so as not to protrude from the lens surface, it is advisable to slightly narrower than the diameter of the lens surface.

On the other hand, the tool for processing the peripheral wall of the lens to be processed in this apparatus is composed of a cylindrical grindstone 4 having a grinding surface on its side surface.
This is a state in which a rotation mechanism (not shown) rotates the center axis 0 ₃ in the direction of arrow n _{3 with the} center axis being the rotation center axis. The peripheral wall is ground by being pressed with the pressure P ₃ .

As the grindstone for processing the peripheral wall, for example, #
An electrodeposited diamond grindstone of about 200 to # 400 can be used.

In this example, the axis 0 ₄ and is further provided a roller 5 which rotates in the n ₄ direction about the, pressurized in the arrow P ₄ direction while rotating the roller 5, against the peripheral wall of the processed lens 1 By contacting, the rotation of the lens 1 to be processed can be assisted or promoted. It should be noted that the roller 5 is not required to be provided as long as the lens 1 to be processed can be rotated about the peripheral wall with the grindstone 4.

The plate rotating mechanism, the swinging mechanism, the turning mechanism, the pressure mechanism, the grindstone and roller rotating mechanism, and the pressure mechanism in this apparatus may be appropriately selected from known configurations and used. In addition, these may be provided separately, or two or more thereof may be integrated.

Next, the precise grinding process by this device will be described.

First, the surface of the lens 1 to be preliminarily processed into a shape close to the finished shape is preliminarily processed by the tool 3a, that is, the surface to be precisely ground into a spherical surface having a radius of curvature r ₁ is used as the lower surface, and the abrasive is preliminarily used. It is placed on the tool 3b that has been attached to the upper surface of the lens 1 to be processed, that is, the radius of curvature r ₂
The tool 3b is placed on the surface to be precisely ground on the spherical surface of.

Here, the pressure P of the pressurizing mechanism that presses the tool 3b is high enough to maintain the sandwiched state of the lens 1 to be processed between these tools in a rotated state and process both lens surfaces. Then, while supplying the working fluid from the supply means 6, the respective tools are rotated in the n ₁ and n ₂ directions by the rotating mechanism. Then, by the rotation of each tool, machining tool surfaces 7a and 7b having predetermined radii of curvature r ₁ and r ₂ are formed, and these surfaces are pressed against the lens surface of the lens to be processed with a predetermined pressure, and the machining tool surface 7a , 7b causes the lens to be processed to rotate on its axis, and grinding proceeds in that state.

In order to obtain a stable rotation state of the lens 1 to be processed when rotating each tool, it is preferable that the rotation start-up from the start of rotation is performed as slowly as possible. At this time, if the rotation of the lens 1 to be processed stabilizes while gradually increasing the rotation, the predetermined number of rotations required for grinding may be taken all at once. Also, if either one of the rotation speeds is extremely high, the frictional force on that side increases, and the lens 1 to be processed jumps out between the processing tools 3a and 3b. It is good to do it.

A variable speed rotating mechanism such as an inverter can be used for controlling the rotation speed.

Simultaneous spherical processing of both lens surfaces is stable, and when each lens surface is in complete contact with the processing tool surfaces 7a, 7b,
The rotation center axes 0 ₁ and 0 ₂ of the tool are slightly swung around the centers of curvature r ₁ and r ₂ . As a result, the lens surface can be ground thoroughly.

Further, the pair of rotating grinding means is stably sandwiched and ground, and both lens surfaces and the processing tool surfaces 7a and 7b are processed.
When and are in sufficient contact with each other,
The pressing direction by 7a, 7b and the axis passing through the spherical core of the processing tool surfaces 7a, 7b coincide with each other, that is, the lens 1 to be processed is bell clamped by these tools. Moreover, as described above, the lens 1 to be processed rotates about the axis passing through the spherical core along the pressing direction, that is, the axis passing through the spherical core of the processing tool surfaces 7a and 7b (the optical axis common to both spherical surfaces). The lens 1 to be processed is centered.

In this state, when the outer wall processing grindstone 4 is brought into contact with the lens to be processed at a predetermined pressure P ₄ by the pressure P generated by the pressing mechanism,
After being raised enough to maintain the sandwiched state by 3a and 3b, the grindstone 4 is rotated at a high speed and brought into contact with the peripheral wall of the lens to be processed with a predetermined pressure. At this time, if the pressure contact force of the grindstone 4 is large, the lens 1 to be processed may not rotate smoothly. Therefore, in such a case, for example, a cylindrical roller having the rubber ring 5 may be rotated. It is sufficient to bring them into contact with each other to assist or promote the rotation of the lens 1 to be processed.

In this way, with the grindstone 4, the axis 0 ₅
The peripheral wall of the lens to be processed, which rotates around, is processed symmetrically to the axis, that is, the lens 1 to be processed is centered.

In the present invention, for example, a concave meniscus or a plano-concave lens can be processed by changing the configuration of the lens surface processing tool.

For example, a plano-concave lens can be processed by the device having the configuration shown in FIG.

In this apparatus, a disk-shaped Thai sala 2b, rotates about the axis 0 ₅ along with its rotation, and the working tool surface 3b to form a planar machining tool surface 7b at right angles to the axis is provided There is. The pressing direction by each processing tool surface is a direction that is perpendicular to the processing tool surface 7b and passes through the spherical core of the spherical processing tool surface 7a.

In the example described above, it was an embodiment of the present invention for precise grinding and centering of the lens surface, but depending on the configuration of the lens to be processed and the desired surface accuracy, It goes without saying that the shape and configuration can be variously changed.

Further, as the processing tool in the present invention, not only processing using fixed abrasives but also tools using free abrasives can be used.

On the other hand, if the tool for peripheral wall processing is a tool for forming,
The peripheral wall can be centered in any shape. Further, as the surface processing tool, if it is possible to form a processing tool surface in the present invention in a rotating state, those that do not have a continuous surface as in the above embodiment, such as a groove on the tool surface Even if it is provided and is not continuous on the entire surface, it can be used as long as it can form a machining tool surface having a desired shape in a rotating state.

Further, the present invention can be suitably applied not only to the processing of the lens as in the above-described embodiment but also to the simultaneous processing of three surfaces of various members having a disk-shaped or columnar portion having two facing surfaces.

〔The invention's effect〕

For example, in the case of processing a lens, a pair of opposing lens surfaces and centering processing can be simultaneously performed by one processing apparatus. According to the present invention, two opposing surfaces having a predetermined shape are provided. It is possible to simultaneously process the upper surface, the lower surface and the peripheral wall of various members having a disk having a surface or a cylindrical portion with one processing device, and the number of processing devices and those It is possible to significantly reduce the occupied space of.

Also, since the upper surface, the lower surface and the peripheral wall are machined simultaneously,
The processing time has also been greatly reduced.

Moreover, since the peripheral wall of the workpiece is machined while the upper and lower surfaces to be machined by the surface processing tool are held, that is, the upper and lower surfaces already finished with a metal clamp are held to secure the peripheral wall. Since the conventional processing method for processing is not used, there is no need to consider the problem of damage to the surface to be processed.

Particularly when the present invention is used for processing an optical element such as a lens,
There is no need to worry about the functional surface being damaged by the holder during centering.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view showing the configuration of a fine grinding processing device of the present invention for performing fine grinding (metal pellet) processing of a biconcave spherical lens, and FIG. 2 is a positional relationship of each main constituent element in the device. 3 is a schematic vertical sectional view of another example of the processing apparatus of the present invention. 1: Lens to be processed, 2a, 2b: Plate 3a, 3b: Tool for lens surface processing 4: Grinding stone, 5: Roller 6: Polishing liquid supply means, 7a, 7b: Processing tool surface

Claims (11)

[Claims] 1. A work piece having different peripheral velocities, each of which has a surface shape corresponding to a surface to be formed, is in contact with each of two facing work surfaces of a work piece, and is pressed against each other. A process of simultaneously holding two workpiece surfaces facing each other while maintaining a sandwiched state of the workpiece between a pair of processing tool surfaces that press an object; and sandwiching and rotating between the tool surfaces. And a process of processing the peripheral wall of the work piece in a state of being symmetrical about the rotation center axis. 2. One of the pair of machining tool surfaces has a spherical shape, the other has a plane surface, and the pair of machining tool surfaces presses a workpiece in a direction perpendicular to the plane surface. The three-sided simultaneous processing method according to claim 1, wherein the peripheral wall is processed in a state where the processing tool surface and the processing surface are sufficiently in contact with each other. 3. The pair of machining tool surfaces both have a spherical shape, and the machining tool surfaces press the workpiece in a direction along an axis passing through the spherical cores of both spherical surfaces. The three-sided simultaneous processing method according to claim 1, wherein the peripheral wall is processed in a state where the surface to be processed is in sufficient contact. 4. The spherical machining tool surface has a spherical zone shape having a width smaller than the diameter of the surface to be machined, and the spherical zone is formed by rotating about its central axis. The simultaneous three-side processing method according to claim 2 or 3. 5. A work piece having different peripheral velocities, being in contact with each of two facing work surfaces of a work piece in a surface shape corresponding to a surface to be formed, and in a direction in which they are pressed against each other. A pair of machining tools surfaces for pressing an object, and a pair of surface machining tools provided so as to maintain a sandwiched state of the workpiece between these machining tool surfaces; and between the machining tool surfaces A peripheral wall machining tool which is brought into contact with a peripheral wall of a workpiece to be sandwiched and which can symmetrically machine the peripheral wall around the rotation center axis by utilizing the rotation of the workpiece. A device for simultaneous processing of three surfaces. 6. One of the pair of machining tool surfaces has a spherical shape, the other has a plane surface, and the pair of machining tool surfaces presses a workpiece in a direction perpendicular to the plane surface. An apparatus for simultaneous processing of three surfaces according to claim 5, which is provided. 7. A patent in which the pair of machining tool surfaces both have a spherical shape, and the machining tool surfaces press the workpiece in a direction along an axis passing through a spherical core of each spherical surface. The apparatus for simultaneous processing of three surfaces according to claim 5. 8. A surface processing tool forming the spherical processing tool surface has a spherical zone shape having a width smaller than the diameter of the surface to be machined, and the spherical zone has a central axis thereof. The apparatus for simultaneous three-side machining according to claim 6 or 7, wherein the machining tool surface having a spherical shape is formed by rotating about a center. 9. An apparatus for simultaneous three-side machining according to claim 8, wherein the spherical surface machining tool can be swung around the center of curvature of the spherical machining tool surface. 10. The apparatus for simultaneous machining of three surfaces according to claim 8 or 9, wherein the rotational speed of the surface machining tool can be gradually increased. 11. A pressing method according to claim 5, wherein the pressing force of the processing tool surface against the surface to be processed can be changed as desired.
The apparatus for simultaneous processing of three surfaces according to any one of 10 items.