RU1771925C - Method of optical member alignment - Google Patents

Abstract

Usage: in the optical industry when centering the optical part in the form of a cap. Essence: in the workpiece 1, grinding, an additional flat base surface A is made. Then, part 1 with a convex surface is based on a device 2 made in the form of a hollow steel thin-walled cylinder with a conical surface for contact with the part 1. Using the second device 3 having a flat base surface B. tighten item 1 to the fixture. The device 3 is made in the form of a steel cylinder 4, the base plane of which is covered with a smooth rubber gasket 5. Parts 1 and devices 2 and 3 report synchronous rotation, as a result of which they are centered using tool 6, i.e. make the base cylindrical surface B. 3 ill.

Description

Fig.z

The invention relates to optical production technology, in particular, to methods for centering an optical part in the form of a cap, and can be used in the development of appropriate technological processes.

Known optical methods are not suitable for harvesting operations, when the roughness of the workpiece Ra 0.32-0.16 μm does not allow to obtain a self-collimating glare, and are not suitable for final operations, since the radii of the refracting surfaces of the cap differ by a small amount and auto-collimation glare practically coincide.

Known mechanical methods for the same reason do not provide high accuracy of centering of the parts in the form of a cap.

These methods do not provide high centering accuracy. There are two reasons for this: firstly, the error of the method depends on the angle between the tangents to the refracting surfaces at the point of contact with the centering cartridges, for cap-shaped lenses this angle is less than 12 °, so the centering error will exceed 0.02 mm; secondly, the thickness difference of the part leads to an additional centering error of up to 0.05 mm.

The purpose of the invention is to improve the centering accuracy of a cap-shaped optical part.

This goal is achieved by the fact that in the known method, in which the part is based on a convex surface in a thin-walled cylinder and using the second device they are pressed, and then the parts and devices communicate synchronously, the second device is taken with a flat base surface, and with the sides of the concave surface provide an additional flat base surface.

Appliances with a flat base surface are known in other sets of features of other technical solutions. However, there they are not intended to improve the alignment accuracy of the cap-shaped optical parts. The second distinctive operation of the method is not known to the authors. Therefore, taking into account the achieved positive effect, the authors conclude that the proposed technical solution meets the criterion of a significant difference.

The proposed method is illustrated by drawings, in which Fig. 1 shows a lens blank after fine grinding of a convex surface; Fig. 2 shows a lens blank after manufacturing an additional flat base surface; Fig. 3 is a diagram of the base of a lens blank in devices.

After the operation of fine grinding the convex spherical executive (refractive) surface, the blank 1 of the cap lens has the form shown in FIG. 1 (the concave surface is not processed). Here, the points Oi and Oa are the centers of curvature of the convex and concave surfaces, respectively, and R is the radius of curvature of the convex surface.

5 The essence of the centering method is as follows.

First, in the workpiece 1 grinding perform additional flat base

0 surface A.

Then, the component 1 is based on a convex surface in the device 2 and using the second device 3 having a flat base surface B,

5 tighten part 1 to the device 2 (Fig.Z).

Structurally, fixture 2 is a hollow steel thin-walled cylinder (cartridge) with a conical

0 surface for contact with the part. The tool 3 is a solid steel cylinder 4, the base plane B of which is covered with a smooth rubber gasket 5. The outer diameter d of the cartridge 2

5 are selected in the range of 0.85 R d 2R.

Under the action of the compressive forces Pi and P2, the part 1 self-centers. If in the initial position, part 1 occupied a position in which the axis of its convex surface, passing through the point Oi perpendicular to plane A, does not coincide with the axis of tool 2, then two unbalanced forces N and F. N is the resultant of forces NI and N2 directed

g normal to the convex and flat surfaces of part 1, respectively. F is the resultant friction force FI and F2 directed tangentially to the convex and flat surfaces of part 1, respectively. Big

n from forces N or F will move part t to a position in which the axis of the convex surface coincides with the axis of the tool 2,

Part 1 and fixtures 2 and 3 result in synchronous rotation, during which centering is carried out using tool b, that is, the base cylindrical surface B is made. In the course of further processing, the concave surface is made on the part

5

1, this surface B and the convex surface of part 1 are used as base.

Example. In the manufacture of the cap part with R 30 mm and a thickness of 5 mm, convex and an additional flat base surface were successively made by grinding (Rz 1.25) on it. The following were used as devices: a hollow thin-walled steel cylinder with external diameters of 30 mm and a solid steel cylinder with an external diameter of 80 mm and with a rubber gasket 3 mm thick. The fixtures and the part were installed in the spindle of the centering machine ЦС 100. The preload of the part was carried out with a force of 120 N. The speed of rotation of the part and the fixtures varied in the range of 57-200 r / s. The rotational speed of the tool (cutter) was 2800 rpm. As a result of inspection of the batch of the part, it was found that the centering error is 0.01 mm.

Thus, in comparison with the mechanical method of centering optical parts in the form of a cap, the proposed method 5 times increases the accuracy of centering. A 7% increase in centering accuracy increases yield.

Claims (1)

SUMMARY OF THE INVENTION A method for centering an optical component, in which the component is supported by a convex surface in a thin-walled cylinder and is pressed with the aid of a second device, the components and devices transmit synchronous rotation, characterized in that. in order to improve the centering accuracy of meniscus-shaped optical parts, the second device is taken with a flat base surface, and an additional flat base surface is made on the parts from the concave surface. Wg 1.25 FIG. 1 ig. & FIG. 2