Method for micro-grinding tip-accurately induced brittle fracture forming of curved mirror surface

Patent metadata

Field	Value
Publication number	US-10745313-B2
Application number	US-201616340388-A
Country	US
Kind code	B2
Filing date	Dec 23, 2016
Priority date	Oct 10, 2016
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

The present invention provides a method for micro-grinding tip-accurately induced brittle fracture forming of a curved mirror surface. The method includes the steps of: grinding a surface of an optical glass material by means of a V-shaped tip of a diamond grinding wheel to form a V-shaped microgroove having a groove micro-tip; setting two supporting points with a distance of L therebetween on one side of the optical glass material where the microgroove is machined, providing a loading pressing head having a horizontal deviation distance of l between a loading point and the groove micro-tip on the other side of the optical glass material, and allowing the loading pressing head to perpendicularly apply a loading force F onto the optical glass material with a loading speed of v, and forming a penetrated smooth curved mirror surface within 0.3 millisecond via the loading point of the loading force F and under induction of the groove micro-tip.

First claim

What is claimed is:

1. A method for grinding tip-accurately induced brittle fracture forming of a curved mirror surface, comprising:
grinding a surface of a workpiece, which is a rectangle plate, by means of a V-shaped tip of a diamond grinding wheel to form a V-shaped groove having a groove tip; and
setting two supporting points with a distance of L therebetween on one side of the workpiece where the V-shaped groove is machined, providing a loading pressing head having a horizontal deviation distance of 1 between a loading point and the groove tip on the other side of the workpiece, and allowing the loading pressing head to perpendicularly apply a loading force F onto the workpiece at a loading speed of v, and forming a penetrated smooth curved surface via the loading point of the loading force F and under induction of the groove tip,
wherein the loading force F is:

F
=

22.1
⁢

⁢

B
⁡

(

W
-

h
v

)

2

⁢

(

0.3333
⁢

r
v

+
0.0104

)

0.4552

Lr
v
0.4552

⁡

(

1
+

0.54
⁢

(

1
+

0.0104

0.3333
⁢

r
v

)

-
0.8897

)

,

wherein B represents a workpiece width parallel to a longitudinal direction of the V-shaped groove, W represents a workpiece thickness parallel to a direction of the loading force, h v represents a groove depth, r v represents a groove tip radius, and L represents a supporting point distance.

2. The method for grinding tip-accurately induced brittle fracture forming of a curved mirror surface according to claim 1 , wherein the loading speed v is less than 50 mm/min.

3. The method for grinding tip-accurately induced brittle fracture forming of a curved mirror surface according to claim 2 , wherein when an included angle θ formed between a central line of the V-shaped groove and the surface of the workpiece is 90°, if the horizontal deviation distance 1 between the loading point of the loading pressing head and the groove tip is equal to the workpiece thickness W, a convex circular arc-shaped curved surface with a radius R of the workpiece thickness is formed; and if the horizontal deviation distance 1 between the loading point and the groove tip is less than the workpiece thickness W, a convex circular arc-shaped curved surface with a radius

R
=

W
2

2
⁢
l

is formed.

4. The method for grinding tip-accurately induced brittle fracture forming of a curved mirror surface according to claim 2 , wherein when an included angle θ formed between a central line of the V-shaped groove and the surface of the workpiece is less than 90° and an intersection between the central line and a plane where the loading point of the workpiece is located is at a to-be-stripped portion of the workpiece, if the horizontal deviation distance

l
=

1
+

cos
⁢

⁢
θ

sin
⁢

⁢
θ

⁢
W

,

a convex circular arc-shaped curved surface with a radius

R
=

2
⁢
W
⁢

⁢

cos
2

⁢
θ

+

W
⁢

⁢
cos
⁢

⁢
θ

sin
2

⁢
θ

is formed, and if the horizontal deviation distance

Assignees

• Univ South China Tech

Inventors

• Xie Jin
• Zhang Long

Classifications

• C03B33/04 Primary

  Cutting or splitting in curves, especially for making spectacle lenses · CPC title

• C03B33/10

  Glass-cutting tools, e.g. scoring tools · CPC title

• C03B33/033

  Apparatus for opening score lines in glass sheets · CPC title

• B24B19/028

  for microgrooves or oil spots · CPC title