JP2000153439A - Nc triaxial centripetal grinding polishing device and grinding polishing method of glass lens using nc triaxial grinding polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cope with a lens having a different radius of curvature by arranging a control mechanism for controlling an X axis driving mechanism, a Z axis driving mechanism and a θ axis driving mechanism so that an intersection of the Y axis and the Z axis is always positioned on the same circular arc with the rotary center as the center. SOLUTION: An X axis driving mechanism 20, a Z axis driving mechanism 30 and a θ axis driving mechanism 40 are controlled by a control mechanism so that an intersection of both the rotational axis Y of a grinding polishing cutter and the rotational axis Z of a work moves on the same circular arc with the rotary center 41 as the center. Thus, when controlling positions of the work and the grinding polishing cutter, grinding polishing work of a spherical surface can be performed by the same NC triaxial grinding polishing device regardeless of a radius of curvature of the spherical surface of the work. Since abrasion cannot be avoided in the grinding polishing cutter, even if abrasion of the grinding polishing cutter makes progress, the X axis driving mechanism 20 and the Z axis driving mechanism 30 are desirably driven so that the rotary center is always positioned on the spherical surface of the work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for grinding and polishing a glass lens.
The present invention relates to a method of grinding and polishing a glass lens using a C3-axis spherical center grinding and polishing apparatus and an NC 3-axis grinding and polishing apparatus.

[0002]

2. Description of the Related Art Conventionally, in grinding and polishing a glass lens, a work spindle holding a lens to be polished is rotationally driven, while a lens to be polished is ground and polished. A grinding and polishing blade having a polished spherical surface is held on a tool spindle, and the tool spindle is oscillated about a ground and polished spherical surface on an arc corresponding to a radius of curvature of the spherical surface. Therefore, the swing radius of the tool spindle must be changed according to the radius of curvature of the spherical surface of the grinding and polishing lens. Conventionally, an arc cam has been used to change the swing radius of the tool spindle. However, preparing an arc cam for each lens having a different radius of curvature is costly, and requires a very long time to change the set, which is not suitable for various kinds of small-quantity production.

[0003]

SUMMARY OF THE INVENTION The present invention has been developed without using an arc cam.
An object of the present invention is to provide a grinding and polishing apparatus capable of coping with lenses having different radii of curvature.

[0004]

According to an aspect of the present invention, there is provided a work spindle for holding a lens to be polished and rotating the lens to be polished about a Z-axis connecting the centers of the spherical surfaces on the front and back; A Z-axis drive mechanism for driving the spindle by numerical control in the Z-axis direction; an X-axis drive mechanism for driving the work spindle by numerical control in the X-axis direction orthogonal to the Z-axis; A tool spindle for holding a grinding / polishing blade having a grinding / polishing sphere corresponding to the spherical surface of the grinding / polishing lens, and driving the grinding / polishing blade to rotate about a Y-axis passing through the center of the grinding / polishing sphere; A .theta.-axis drive mechanism for numerically controlling a swing center located on the Y-axis for reciprocating rotation; an X-axis drive mechanism, a Z-axis drive mechanism, and a .theta.-axis drive mechanism;
And a control mechanism for controlling the intersection with the axis to be always located on the same arc centered on the swing center.

The center of swing of the tool spindle is preferably located on the spherical surface of the lens to be ground and polished. Also,
It is preferable that the Z-axis drive mechanism and the X-axis drive mechanism drive the work spindle in the Z-axis direction and the X-axis direction so as to compensate for the wear as the grinding and polishing blade advances.

According to an aspect of the present invention, there is provided a work spindle for holding a lens to be polished and rotating the lens to be polished about a Z-axis connecting the centers of the spherical surfaces on the front and back; A Z-axis drive mechanism for numerically controlling and driving the Z-axis direction; an X-axis drive mechanism for numerically controlling and driving the work spindle in an X-axis direction orthogonal to the Z-axis; A tool spindle for holding a grinding / polishing blade having a grinding / polishing sphere corresponding to the spherical surface of the grinding / polishing lens, and rotating the grinding / polishing blade about a Y-axis passing through the center of the grinding / polishing sphere;
An X-axis driving mechanism using an NC three-axis grinding and polishing apparatus having a tool spindle for numerically controlling a tool spindle around a swing center located on the Y-axis and reciprocatingly rotating the tool spindle.
It is characterized in that the axis driving mechanism and the θ axis driving mechanism are controlled such that the intersection of the Y axis and the Z axis is always located on the same arc centered on the swing center.

[0007]

1 and 2 show an example of the overall configuration of an NC three-axis spherical center grinding and polishing apparatus used in the present embodiment.
The spindle 11 is mounted in the machine frame 11 in the horizontal direction (X
An X-axis drive mechanism 20 for driving in the (axial direction) is provided. The X-axis drive mechanism 20 is provided with the spindle unit 10
And an X-axis servomotor 22 that numerically controls the position of the spindle unit 10 along the guide rail 21.

[0008] The spindle unit 10 also has a work spindle 12 in a vertical direction (Z-axis direction) perpendicular to the X axis.
, A Z-axis drive mechanism 30 is provided. This Z
The shaft drive mechanism 30 includes a guide rail 31 for guiding the work spindle 12 in the Z-axis direction, and a Z-axis servomotor 32 for numerically controlling the position of the work spindle 12 along the guide rail 31. The work spindle 12 is driven to rotate about the Z axis by a rotation drive motor 13. At the lower end of the work spindle 12, a lens holder 14 for holding a work (a ground glass lens to be ground) W is integrally provided. The workpiece W is placed on the lens holder 1 such that a line connecting the centers of the front and rear spherical surfaces coincides with the Z axis.
4 is held.

The machine frame 11 also includes a spindle unit 1.
Below 0, a θ-axis drive mechanism 40 for reciprocatingly rotating the tool spindle holder 42 about the swing center 41 is provided. That is, the swing center 41 is provided on the machine casing 11.
An arc guide 43 composed of an arc centered at the center and a sector gear 44 concentric with the arc guide 43 are fixed, and the tool spindle holder 42 is movably guided along the arc guide 43. The tool spindle holder 42 has a gear mechanism that meshes with the sector gear 44, and the tool spindle holder 42 is driven via the gear mechanism and the sector gear 44 to numerically control a position on an arc centered on the swing center 41. A servo motor 45 is mounted.

A tool spindle 46 is supported by the tool spindle holder 42 so as to be rotatable about a Y axis passing through the swing center 41. The tool spindle 46 is
It is driven to rotate about the Y axis by a rotation drive motor 47. A tool holder 48 is provided integrally with the tip of the tool spindle 46.
In addition, a grinding and polishing blade C having a spherical surface corresponding to the shape of the surface to be ground and polished of the work W is supported. The grinding and polishing blade C is supported by the tool holder 48 such that the Y axis passes through the center of the spherical surface.

From the above machine configuration, the tool spindle 4
When the swing center 41 of the tool spindle 6 (tool spindle holder 42) is at a fixed position on the machine frame 11, the work spindle 12
The work W held by the lens holder 14 at the tip of
Any position can be set with respect to the grinding and polishing blade C. FIG. 2 shows the possibility of the position of the work W with respect to the grinding and polishing blade C, but does not show a relative position essential for the present embodiment. This embodiment is characterized in that the X-axis drive mechanism 20 and the Z-axis drive mechanism 3 of the three-axis numerical controller described above.
It is characterized in that a control mechanism for controlling the intersection between the Y axis and the Z axis using the 0 and θ axis driving mechanism 40 so as to always be located on the same arc centered on the swing center 41 is provided. .

FIG. 2 shows an example of the control system. A control circuit (CPU) 50 is provided with information on the work W, such as a lens radius of curvature, a lens center thickness, and a wear amount of the grinding and polishing blade C. Can be The control circuit 50 controls the X-axis drive mechanism 20 (X) so that the intersection of the Y-axis and the Z-axis is always located on the same arc centered on the swing center 41 based on these pieces of information.
The axis servomotor 22), the Z-axis drive mechanism 30 (Z-axis servomotor 32), and the θ-axis drive mechanism 40 (θ-axis servomotor 45) are controlled. The control circuit 50 also controls the rotation of the rotation drive motor 13 and the rotation drive motor 47 and the rotation speed thereof.

FIGS. 4 to 7 show a specific example in which the intersection of the Y axis and the Z axis is controlled to always be located on the same arc centered on the swing center 41. FIG. FIG. 4 and FIG.
The work W is an example of a concave lens. In each case, the intersection of the rotation center axis Y of the grinding and polishing blade C and the rotation center axis Z of the work W moves on the same arc P1 centered on the swing center 41. X-axis drive mechanism 20, Z-axis drive mechanism 30, θ
The shaft drive mechanism 40 is controlled. FIG. 4 illustrates a state in which the workpiece W and the grinding and polishing blade C are not in contact with each other, but actually, both are always in contact. As described above, when the positions of the work W and the grinding and polishing blade C are controlled, the work W
Regardless of the radius of curvature of the spherical surface, the same NC three-axis grinding and polishing apparatus can perform the grinding and polishing process on the spherical surface.

In the example of FIG. 4, the swing center 41 is
Are located on the spherical surface of. Further, since the wear on the grinding and polishing blade C is inevitable, the X-axis drive mechanism 20 and the X-axis driving mechanism 20 are so arranged that the swing center 41 is always positioned on the spherical surface of the work W even if the wear on the grinding and polishing blade C progresses. It is preferable to drive the Z-axis drive mechanism 30. For example, S1 indicates the position of the work W before wear, and S2 indicates the position of the work W after wear.

FIG. 5 shows an example in which the swing center 41 does not exist on the spherical surface of the workpiece W. In principle, the work W can be ground and polished even if the swing center 41 is not located on the spherical surface of the work W as described above. However, in order to reduce the amount of movement Xr of the grinding and polishing blade C in the X-axis direction, it is preferable that the swing center 41 be located on or near the spherical surface of the workpiece W.

FIGS. 6 and 7 show examples in which the work W is a convex lens. As in the case of the concave lens, the X-axis is set so that the intersection of the rotation center axis Y of the grinding and polishing blade C and the rotation center axis Z of the workpiece W moves on the same arc P2 centered on the swing center 41. The drive mechanism 20, the Z-axis drive mechanism 30, and the θ-axis drive mechanism 40 are controlled. FIG. 6 shows that the swing center 41 is the work W
7 shows a case where the swing center 41 is not located on the spherical surface of the workpiece W, and FIG.
This corresponds to FIG. S1 and S2 in FIG. 6 correspond to FIG.
3 shows the position of the workpiece W before and after the grinding and polishing blade C is worn.

[0017]

According to the present invention, lenses having different radii of curvature can be ground and polished by the same NC three-axis spherical center polisher.

[Brief description of the drawings]

FIG. 1 is an overall front view showing an embodiment of an NC three-axis spherical center grinding and polishing apparatus according to the present invention.

FIG. 2 is an enlarged front view of a main part of FIG.

FIG. 3 is a block diagram showing a control system of the NC three-axis ball center grinding and polishing apparatus according to the present invention.

FIG. 4 is a diagram showing a control example of the NC three-axis ball center grinding and polishing apparatus according to the present invention.

FIG. 5 is a diagram showing another control example of the NC three-axis ball center grinding and polishing apparatus according to the present invention.

FIG. 6 is a diagram showing still another control example of the NC three-axis ball center grinding and polishing apparatus according to the present invention.

FIG. 7 is a diagram showing another control example of the NC three-axis ball center grinding and polishing apparatus according to the present invention.

[Explanation of symbols]

 W Work (grinding and polishing glass lens) C Grinding and polishing blade P1 P2 Movement locus (arc) of intersection of Z axis and Y axis 10 Spindle unit 11 Machine frame 12 Work spindle 13 Rotation drive motor 14 Lens holder 20 X axis drive mechanism 21 Guide rail 22 X-axis servo motor 30 Z-axis drive mechanism 31 Guide rail 32 Z-axis servo motor 40 θ-axis drive mechanism 41 Center of swing 42 Tool spindle holder 43 Arc guide 44 Sector gear 45 θ-axis servo motor 46 Tool spindle 47 Rotary drive motor 48 Tool holder 50 Control circuit

Claims (4)

[Claims] A work spindle for holding a ground lens to be polished and rotating the ground lens to be rotated about a Z-axis connecting the centers of the front and rear surfaces of the lens; and numerically controlling the work spindle in the Z-axis direction. A Z-axis drive mechanism that drives the actuator;
An X-axis drive mechanism for numerically controlling and driving the work spindle in an X-axis direction orthogonal to the Z-axis; and a grinding / polishing sphere corresponding to a spherical surface of the grinding / polishing lens for grinding / polishing the lens to be ground / polished. A tool spindle for holding a grinding and polishing blade and rotating the grinding and polishing blade about a Y-axis passing through the center of the grinding and polishing spherical surface; and moving the tool spindle around a swing center located on the Y-axis. A θ-axis drive mechanism for numerically controlling the reciprocating rotation; and an X-axis drive mechanism, a Z-axis drive mechanism, and a θ-axis drive mechanism, wherein the intersection between the Y-axis and the Z-axis is always centered on the swing center. And a control mechanism for controlling so as to be located on the same circular arc. 2. The NC three-axis ball-grinding and polishing apparatus according to claim 1, wherein the swing center of the tool spindle is located on the spherical surface of the lens to be ground. 3. The NC three-axis ball center grinding and polishing apparatus according to claim 1, wherein the Z-axis drive mechanism and the X-axis drive mechanism are configured to compensate for the wear as the wear of the grinding and polishing blade progresses. An NC 3-axis spherical center grinding and polishing apparatus that drives a spindle in the Z-axis direction and the X-axis direction. 4. A work spindle for holding a lens to be polished and polished and rotating the lens to be polished about a Z-axis connecting the spherical centers of the front and back surfaces thereof; and numerically controlling the work spindle in the Z-axis direction. A Z-axis drive mechanism that drives the actuator;
An X-axis drive mechanism for numerically controlling and driving the work spindle in an X-axis direction orthogonal to the Z-axis; and a grinding / polishing sphere corresponding to a spherical surface of the grinding / polishing lens for grinding / polishing the lens to be ground / polished. A tool spindle for holding a grinding and polishing blade and rotating the grinding and polishing blade about a Y axis passing through the center of the grinding and polishing spherical surface; and moving the tool spindle around a swing center located on the Y axis. A θ-axis drive mechanism for numerically controlling the reciprocating rotational movement;
Using a C3-axis grinding and polishing apparatus, the X-axis drive mechanism, the Z-axis drive mechanism, and the θ-axis drive mechanism are
A method of grinding and polishing a glass lens using an NC three-axis grinding and polishing apparatus, characterized in that an intersection of the Y axis and the Z axis is controlled to always be located on the same arc centered on the swing center.