SU1237387A1 - Method of working plain surfaces of optical parts - Google Patents

Description

The invention relates to the processing technology of optical parts made of glass, ceramics, quartz, and other non-metallic materials used in optical-mechanical, instrument-making, and other industries.

The purpose of the invention is to improve the accuracy of shaping the surfaces of optical parts by eliminating the shaping error by deforming the tool.

When implementing this method of processing the flat surfaces of optical parts, it becomes possible to change the shape of the working surface of the instrument due to the deformation of its body, caused by the pressing force P of the tool and the part to each other, directly during processing. However, by adjusting the pressing force, the tool body can be deformed only in the direction of increasing the convexity of its surface adjacent to the diamond abrasive layer. If you give the working surface of the diamond abrasive layer a tool of originals; about a concave shape, then by deforming the tool body it is possible to achieve its alignment and even bending in the direction of the convexity during processing.

Thus, the shape of the working surface of the tool must be concave, and the clamping force must be such as to ensure the bend of the tool at its edge by a magnitude equal to the arrow of the concavity of the working surface of the tool D) / 8R (D is the diameter of the tool). In addition, the radius of curvature of the working surface of the tool should be i.e. less than 0.8 () m, since at its lower values the alignment of the working surface of the tool during processing requires significant loads (4000 N), which can be achieved with the current Time in the equipment industry is impossible, which negatively affects the accuracy of shaping the flat surfaces of optical components.

Example. Ll will implement the way of using. 1c then the circle is a casing with a diameter of 400 mm, with a working surface of the diamond layer of a concave shape with an arrow of concavity Ah I) μm. The optical parts (blocks of 0350 mm) were ground on a PMM-100 machine (LOH, Germany). The rotation of the tool and the block of the machined parts was osuichest at speeds of 68 s and 67 s, respectively. Processing cycle 60 s. The shape of the working surface of the instrument and the flatness of the machined surface were determined by means of the measuring device, and the measuring bracket and the interference method, respectively.

The clamping force at which the process of fine grinding of flat surfaces of optical parts with diamond was carried out

tool 25 mm thick, the body of which is made of steel with an elastic modulus of E 20-10 N / m, was calculated as follows. The radius of curvature of the surface of the diamond plan aibs is equal to

R DV8Ah (0.4) / 8-10-10 2-10 m, and the pressing force P is

P 125:

) - 20-10

 1562 N.

2-10

The result of calculating P for different R is given in the table (clause 3-8). With these values, the pressing force was processed 20 blocks of optical parts, while the processing accuracy was N 0.25 - 1.0 µm on a diameter of 350 mm. When machining the surfaces of optical parts of a gfi pompi tool with a radius of curvature of the working surface, 8-0 (n. 1 --- 2), the clamping force P 4000 N (maximum for the PLM-400 machine) was not enough to deform the tool body that aligns its working surface, resulting in significantly reduced the accuracy of shaping optical parts.

The table shows the effect of the curvature of the working surface of the instrument on the accuracy of shaping the flat surfaces of optical components.

0.6 0.7 0.8 0.9

3900

3500

3100

2100

2.0

1500

55

1200

1237387 34

Fine grinding of flat surface-type (10 blocks). At the same time, the non-flatness of the optical parts made the so-called surface of the treated surfaces on the same

the same method adopted as the pro-diameter (350 mm) was 10–25 µm.

Claims (1)

METHOD FOR PROCESSING FLAT SURFACES OF OPTICAL DETAILS with a tool in the form of a diamond-abrasive coating fixed on the body, in which the part and the tool are pressed against each other and give them rotation and relative reciprocating movement, characterized in that, in order to improve the accuracy of surface formation, processing lead a tool with a concave-shaped working surface, the radius of curvature R of which is not less than 800 m, while the clamping force P is chosen from the condition P = - ^ - F ¹ _R E, where h is the thickness of the tool body, m; E - modulus of elasticity of the material of the tool body, N / m ² . Short circuit with QO> a tool with a thickness of 25 mm, the casing of which is made of steel with an elastic modulus E = 2O-1O ¹⁰ N / m ² , was calculated as follows. The radius of curvature of the surface of the diamond faceplate is R = D ² / 8Ah = (0,4) ² / 8-1O-1D ⁶ = 2- ^10: m, and the clamping force P is