CN113967852B

CN113967852B - Processing method of metal multi-surface reflecting prism

Info

Publication number: CN113967852B
Application number: CN202111194632.2A
Authority: CN
Inventors: 陈宝华; 吴泉英; 唐运海; 朱孙泳; 王丞
Original assignee: Suzhou University of Science and Technology
Current assignee: Suzhou University of Science and Technology
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2024-05-07
Anticipated expiration: 2041-10-13
Also published as: CN113967852A

Abstract

The invention discloses a processing method of a metal multi-surface reflecting prism, and belongs to the field of optical ultra-precise processing. The technical scheme is as follows: the related processing method uses a precision mechanical clamp for fixing the prism and uses a single-point diamond lathe to turn the prism. The vertex angle of the prism is alpha, the number of the reflecting surfaces is n, and prism scratches 24 which are consistent with the number n of the reflecting surfaces and are uniformly distributed are engraved at the bottom. The fixture 10 comprises an inclined plane for placing a reflecting prism to be processed, ensuring that the reflecting surface 23 is parallel to the bottom surface, the sum of the inclination angle beta and the top angle a of the prism is 90 degrees, and the fixture scratch 14 is carved below the inclined plane. The turning method comprises the following steps: firstly, adjusting and overlapping the prism scratches 24 and the clamp scratches 14 under a microscope, and fixing the prism through the through hole 12 to finish the processing of the reflecting surface 23; loosening the through hole 12, rotating the prism, overlapping the second prism scratch at the bottom of the prism with the clamp scratch 14, then fixing again, finishing the second surface turning by using the consistent feed amount in the method, and the like until all surfaces are finished.

Description

Processing method of metal multi-surface reflecting prism

Technical Field

The invention belongs to the field of optical ultra-precise machining, and particularly relates to a machining method of a metal multi-surface reflecting prism.

Background

The metal multi-face reflecting prism belongs to the laser core optical elements of scanner, copying machine and code scanner, etc. and possesses several reflecting surfaces, so that the incident light beam can be reflected according to specific mode and time sequence so as to implement deflection, scanning and imaging of light beam. At present, the domestic ultra-precision machining of the multi-surface reflecting prism is mainly finished by milling a single crystal fly cutter, and the precision of the rotation angle is detected by matching an auto-collimation optical instrument, so that the whole structure is complex, and the machining efficiency is lower. For example, chinese patent No. CN1147378 discloses a "processing method of high-precision metal scanning turning mirror", which can reduce the mirror surface tower difference, but the processing efficiency is not high, and the turntable and the auto-collimation instrument are required to cooperate, involving more parts and complicated adjustment. For example, chinese patent No. CN108051880a discloses a "processing method of a metal polygon scanning prism", which is only suitable for milling a single crystal fly cutter due to the asymmetry of the whole structure, but not suitable for turning, and because a plurality of prisms are fixed together by a long rod, the deformation is difficult to control, the tower difference of each prism cannot be effectively controlled, and the precision is difficult to ensure.

Disclosure of Invention

The invention aims to provide a metal polygon mirror processing method which has small repeated positioning error and high surface size precision and is suitable for single-point diamond turning.

The technical proposal for realizing the aim of the invention is that

The processing method is realized by using a precision mechanical fixture for fixing a prism and turning by a single-point diamond lathe, wherein the fixture 10 comprises an inclined plane for placing a reflecting prism to be processed, the reflecting surface 23 is ensured to be parallel to the bottom surface, the sum of the inclined angle beta and the apex angle a of the prism is 90 degrees, the side surface is provided with an arc support 13, and the lower part of the fixture is provided with a fixture scratch 14. The circle center of the arc support bottom 13 coincides with the rotation center of the prism, and the size of the outer circle where the arc is located is equal to the diameter of the bottom 21 of the prism. The vertex angle of the prism is alpha, the number of the reflecting surfaces is n, and the bottom is carved with prism scratches 24. Wherein the prism scratches 24 are formed by scribing each 360/n angle with a single-point diamond lathe with a single-crystal knife in combination with a high-precision C-axis.

In the technical scheme, the method comprises the following steps: the position of the clamp scratch 14 on the clamp is perpendicular to the side edge of the inclined plane, the center of the scratch is coincident with the central axis of the through hole 12, and the scratch can be scored by a single crystal knife to ensure sharp edges and no burrs, so that the subsequent microscope focusing is facilitated.

The lathe may turn the bottom side of the polygon mirror before scoring the prism score 24 to improve the roundness of the prism.

The foregoing description is only a brief summary of the method of the present invention, and it is intended that the technical means of the present invention be understood more clearly by the following description, and that the preferred embodiments described below be more fully described with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic illustration of a single point diamond lathe scoring a bottom scratch of a faceted prism;

FIG. 2 is a schematic view of a processing device and a fixture according to a first embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a multi-group processing method according to a second embodiment of the present invention;

marking: 10. a clamp; 11. a threaded hole; 12. a through hole; 13. arc support bottom; 14. scratching the clamp; 20. a faceted prism; 21. a prism side; 22. a prism rotating shaft; 23. a prism reflection surface 1; 24. a prism scratch; 30. a vacuum chuck; 40. a lathe C shaft; 41. a single crystal knife.

Detailed description of the preferred embodiments

The technical scheme of the invention is further described below with reference to the accompanying drawings and examples.

Referring to fig. 1, the reflecting surface of the polygon prism is n, which is fixed on a C-axis 40 with a positioning accuracy of 0.00001 degrees, the C-axis being rotatable around a central axis by a fixed angle, and a single crystal knife 41 being fed in the Z direction. The C-axis is manually controlled to rotate to a certain angle during scribing, the plane where the single crystal knife is positioned is roughly overlapped with the central plane of a reflecting surface of the prism, then rapid scribing is performed, the width of the scribing is controlled below 2um, the follow-up focusing accuracy is ensured, and the angle of the C-axis at the moment is recorded; the C-axis is then rotated 360/n, the second score is again scored, and so on until the scoring is completed.

Referring to fig. 2, the scribed polygon prism is fixed on the inclined plane of the fixture 10, and the sum of the inclination angle β of the inclined plane and the apex angle a of the prism is 90 degrees, so that the prism can be flattened so that the reflecting surface 23 is parallel to the bottom surface of the fixture; the side of the fixture is provided with an arc support bottom 13, the center position of the arc is coincident with the rotation center of the prism, and the size of the excircle where the arc is positioned is equal to the diameter of the bottom 21 of the prism, so that the arc support bottom is tightly attached to the side of the prism. The clamp scratch 14 is carved below the clamp, is perpendicular to the side edge of the inclined plane and is flush with the through hole 12, and the scratch can be carved by a single crystal knife to ensure that the edge is sharp and free of burrs. The turning method comprises the following steps: firstly, adjusting and overlapping the scratches 24 and 14 of the prism under a microscope, keeping the bottom of the prism closely attached to the arc support 13 during adjustment, fixing the prism through the through hole 12, and fixing the prism on the vacuum chuck 30 through the threaded hole 11 to finish the processing of the reflecting surface 23; and then loosening the through hole 12, rotating the prism, overlapping the second scratch on the bottom of the prism with the scratch 14 of the clamp, fixing again, finishing the second surface turning by using the consistent feed amount in the method, and the like until all the surfaces are finished.

Detailed description of the preferred embodiments

Referring to fig. 3, if the diameter of the vacuum chuck 30 is made into the single-point diamond lathe with the model of 250UPL, the machining limit caliber is generally 300mm, a plurality of groups of clamps 10 are uniformly fixed on the upper surface of the single-point diamond lathe, and the machining is completed in the manner of the first embodiment, so that the machining efficiency can be greatly improved. In addition, the fixture not only can realize the processing of the round bottom multi-surface reflecting prism, but also can be applied to the square bottom multi-surface reflecting prism, and has high practicability.

The embodiment of the invention can show that the metal multi-surface reflecting prism processing method has compact overall structure, and the mode of combining scratches and arc supports avoids using an optical self-alignment instrument and a rotating disc, so that the processing is simplified; the method has the advantages of eliminating repeated positioning errors, improving efficiency and having great application potential in optical ultra-precise turning.

Claims

1. A processing method of a metal multi-surface reflecting prism is characterized by comprising the following steps of:

The processing method is realized by using a precision mechanical clamp for fixing a prism and turning by a single-point diamond lathe, wherein the clamp (10) comprises an inclined plane for placing a reflecting prism to be processed, the reflecting surface (23) is ensured to be parallel to the bottom surface, the sum of the inclined angle beta and the top angle a of the prism is 90 degrees, the side surface is provided with an arc support bottom (13), and a clamp scratch (14) is arranged below the inclined plane; the circle center of the arc support bottom (13) coincides with the rotation center of the prism, and the size of the outer circle where the arc is positioned is equal to the diameter of the bottom (21) of the prism; the vertex angle of the prism is alpha, the number of the reflecting surfaces is n, and prism scratches (24) are carved on the bottom; wherein the prism scratch (24) is formed by scratching every 360/n angle on a single-point diamond lathe by matching a single crystal knife with a high-precision C axis;

the turning method by using the single-point diamond lathe comprises the following steps: firstly, adjusting and overlapping a prism scratch (24) and a clamp scratch (14) under a microscope, keeping the bottom of the prism tightly attached to an arc support base (13) during adjustment, fixing the prism through a through hole (12), and fixing the prism on a vacuum chuck (30) through a threaded hole (11) to finish the processing of a reflecting surface (23); then loosening the through hole (12), rotating the prism, overlapping the second prism scratch at the bottom of the prism with the clamp scratch (14), then fixing again, finishing the second surface turning by using the consistent feed amount of the method, and the like until all surfaces are finished; the two surfaces of the vacuum sucker (30) are parallel, wherein a plurality of groups of threaded connection holes are uniformly distributed on the upper surface so as to be convenient for fixing a plurality of clamps (10), and therefore, the metal multi-surface reflection prism processing method can realize the processing of a plurality of prisms at one time.