A high-precision machining device and method for double convex cylinder

Abstract

The present invention relates to the technical field of ultra-precision processing equipment, and in particular to a high-precision processing device and method for a double convex cylinder, comprising: (1) using a plane grinder to grind the upper and lower surfaces of a blank mirror to a flatness better than 5 microns and a parallelism better than 5 microns; (2) designing a precision positioning tool according to the curvature radius of the upper surface of the cylindrical surface of the blank mirror processed in step (1); (3) using a precision engraving machine to process the upper and lower contours of the blank mirror processed in step (1) to a close fit according to the inner contour of the precision positioning tool in step (2); (4) measuring the horizontal and vertical parallelism of the generatrix of the cylindrical surface of the blank mirror processed in step (3) by a three-coordinate measuring machine. The parallelism of the generatrix of the double convex cylinder can be greatly improved, the aberration level of the cylindrical system can be improved, and thus the beam quality of the laser system can be improved. The double convex cylinder processing method is simple to operate, highly automatic, and cost-saving.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-precision processing equipment, in particular to a high-precision processing device and method for a double convex cylinder. Background Art

[0002] In recent years, cylindrical optical elements have been widely used in high-power optical systems (such as laser-induced nuclear fusion systems, laser weapon systems, high-power laser processing equipment, etc.) to achieve functions such as laser beam shaping and beam expansion. Common ones include biconvex cylinders, plano-convex cylinders, biconcave cylinders, plano-concave cylinders, etc. With the improvement of beam quality, the requirements of laser systems on cylinders are getting higher and higher. They not only require the surface shape accuracy of the cylinder, but also need to strictly control the geometric accuracy error of the cylinder, especially the parallelism error of the generatrix of the upper and lower surfaces of the biconvex cylinder.

[0003] The parallelism error of the generatrix on the upper and lower surfaces of the double convex cylinder includes transverse parallelism and longitudinal parallelism. The transverse parallelism causes the upper and lower cylinders to rotate around the optical axis, resulting in a large astigmatism error, while the longitudinal parallelism causes inconsistent thickness of the cylinder, resulting in a tilt error of the light beam. Therefore, the parallelism of the generatrix of the double convex cylinder needs to be strictly controlled during processing. Summary of the invention

[0004] In view of the above problems, the present invention provides a high-precision processing device and method for a double convex cylinder, which solves the problem of generatrix parallel error in the existing double convex cylinder processing.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a high-precision processing method for a double convex cylindrical surface, comprising the following steps:

[0006] (1) Use a surface grinder to grind the upper and lower surfaces of the blank mirror to a flatness better than 5 microns and a parallelism better than 5 microns;

[0007] (2) designing a precision positioning tool according to the curvature radius of the upper surface of the cylindrical surface of the blank mirror processed in step (1);

[0008] (3) using a precision engraving machine to process the upper and lower contours of the blank mirror processed in step (1) according to the inner contour of the precision positioning tool in step (2) until they fit closely;

[0009] (4) The parallelism of the main line of the cylindrical surface of the blank mirror processed in step (3) in the horizontal and vertical directions is measured by a three-dimensional coordinate measuring machine.

[0010] As an optimization, in step (3), a precision engraving machine is used to process the top and bottom contours of the blank mirror and the inner contour of the positioning tool to a flatness of 5 microns.

[0011] A precision positioning tool comprises a side positioning block and a bottom positioning block. The inside of the side positioning block is hollow, and the bottom positioning block is provided with a placement groove. The bottom surface of the placement groove is arc-shaped, and both side edges are smooth sections.

[0012] As an optimization, a plurality of fixing holes are provided on the edge of the side positioning block.

[0013] The beneficial effects of the present invention are as follows: the high-precision processing device and method of the double convex cylinder provided by the present invention can greatly improve the parallelism of the generatrix of the double convex cylinder, improve the aberration level of the cylindrical system, thereby improving the beam quality of the laser system. It is a double convex cylinder processing method with simple operation, high degree of automation and cost saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of busbar accuracy of the present invention;

[0015] Figure 2 The precision positioning tool of the present invention;

[0016] Figure 3 It is a cross-sectional schematic diagram of the upper surface before processing of the present invention;

[0017] Figure 4 It is a cross-sectional schematic diagram of the upper surface after processing of the present invention;

[0018] Figure 5 It is a cross-sectional schematic diagram of the lower surface before processing of the present invention;

[0019] Figure 6 It is a cross-sectional schematic diagram of the lower surface after processing of the present invention.

[0020] Among them, 1. upper surface busbar, 2. lower surface busbar, 3. side positioning block, 4. bottom positioning block. DETAILED DESCRIPTION

[0021] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] For the convenience of description, if the words "up", "down", "left" and "right" appear in the present invention, they only indicate that they are consistent with the up, down, left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0024] A high-precision processing method for a double convex cylindrical surface comprises the following steps:

[0025] (1) Use a surface grinder to grind the upper and lower surfaces of the blank mirror to a flatness better than 5 microns and a parallelism better than 5 microns;

[0026] (2) designing a precision positioning tool according to the curvature radius of the upper surface of the cylindrical surface of the blank mirror processed in step (1);

[0027] (3) using a precision engraving machine to process the upper and lower contours of the blank mirror processed in step (1) according to the inner contour of the precision positioning tool in step (2) until they fit closely;

[0028] (4) The parallelism of the main line of the cylindrical surface of the blank mirror processed in step (3) in the horizontal and vertical directions is measured by a three-dimensional coordinate measuring machine.

[0029] In step (3), a precision engraving machine is used to process the top and bottom contours of the blank mirror and the inner contour of the positioning tool to a flatness of 5 microns.

[0030] A precision positioning tool comprises a side positioning block 3 located at the top and a bottom positioning block 4 located below the side positioning block, wherein the interior of the side positioning block 3 is hollow, and the bottom positioning block 4 is provided with a placement groove, the bottom surface of the placement groove is arc-shaped, and both side edges are smooth sections; a plurality of fixing holes are provided on the edge of the side positioning block 1; and the inner wall of the side positioning block corresponds one-to-one to the inner wall of the placement groove.

[0031] like Figure 1 As shown, it is a schematic diagram of the generatrix accuracy of the double convex cylindrical mirror of the present invention, wherein the upper surface generatrix 1 and the lower surface generatrix 2 should be parallel in theory. However, due to the existence of processing errors, the upper and lower surface generatrix 1 may have errors in rotation around Z (called lateral parallelism error), causing the double convex cylinder to produce astigmatism, and there may also be errors in rotation around X (called longitudinal parallelism error), resulting in inconsistent cylinder thickness, causing a tilt error in the light beam after passing through the cylinder.

[0032] like Figure 2As shown, the precision positioning tool of the present invention is composed of a side positioning block 3 and a bottom positioning block 4, wherein the side positioning block 3 holds the double convex cylinder of the blank mirror (positioning in the X and Y directions) to control the relative rotation of the upper and lower surfaces of the cylinder around the Z axis (i.e., controlling the lateral parallelism error of the double convex cylinder); the inner edge of the side positioning block 3 is precisely processed by a precision engraving machine to closely match the size of the blank mirror; the bottom positioning block 4 is used to support the edge portion of the double convex cylinder of the blank mirror to control the rotation of the upper and lower surfaces around the X axis (i.e., controlling the longitudinal parallelism error of the double convex cylinder) to make the upper and lower surfaces of the cylinder equally thick; the bottom positioning block 4 is precisely processed by a grinder to achieve a flatness within 5 microns; the side positioning block 3 and the bottom positioning block 4 are connected by four fastening screws.

[0033] like Figure 3 As shown, it is a schematic diagram of the upper surface before processing of the present invention, wherein the rectangular cylindrical blank mirror is installed in the positioning tool, the side surface is tightly matched with the inner side surface of the precision positioning tool, the bottom surface of the cylindrical blank mirror is in contact with the bottom surface positioning block of the precision positioning tool, and then the precision positioning tool is installed on the precision engraving machine.

[0034] like Figure 4 The figure shown is a schematic diagram of the upper surface after processing of the present invention. After the precision positioning tool is installed on the engraving machine, the side edge of the cylindrical mirror is adjusted to be parallel to the linear axis of the engraving machine through the micrometer (that is, the rotation of the cylindrical mirror around the Z axis is controlled), thereby ensuring that the generatrix of the cylindrical surface of the blank mirror is parallel to the side edge of the cylindrical surface to prevent relative rotation, and then the cylindrical surface is formed according to the parameters of the upper surface of the cylindrical surface to obtain the result shown in the figure.

[0035] like Figure 5 As shown, it is a schematic diagram of the lower surface before processing of the present invention. After the upper surface processing of the cylinder is completed, it is taken out and reversed and placed in a precision positioning tool. Similar to the processing of the upper surface, the rotation of the cylinder around the Z axis is still controlled by the inner side of the precision positioning tool, and the rotation of the cylinder around the X axis is controlled by the bottom surface of the positioning tool to achieve lateral parallelism and longitudinal parallelism of the upper and lower surfaces of the cylinder.

[0036] like Figure 6 As shown, it is a schematic diagram of the lower surface after processing of the present invention. Similar to the processing of the upper surface, the parallel error of the upper and lower generatrixes is controlled by adjusting the rotation of the cylinder around the Z axis, and finally the lower surface of the cylinder is processed by a precision engraving machine.

[0037] The above-mentioned specific implementations are only specific cases of the present invention. The patent protection scope of the present invention includes but is not limited to the product form and style of the above-mentioned specific implementations. Any appropriate changes or modifications made to them by ordinary technicians in the technical field that conform to the claims of the present invention shall fall within the patent protection scope of the present invention.

Claims

1. A high-precision processing method for a double convex cylindrical surface, characterized in that: The following steps are involved: (1) Use a surface grinder to grind the upper and lower surfaces of the blank mirror to a flatness better than 5 microns and a parallelism better than 5 microns; (2) designing a precision positioning tool according to the curvature radius of the upper surface of the cylindrical surface of the blank mirror processed in step (1); (3) Using a precision engraving machine, the upper and lower contours of the blank mirror processed in step (1) are processed according to the inner contour of the precision positioning tool in step (2) until they fit closely; (4) Measuring the horizontal and vertical parallelism of the generatrix of the cylindrical surface of the blank mirror processed in step (3) by a three-dimensional coordinate measuring machine; The precision positioning tooling includes a side positioning block and a bottom positioning block. The interior of the side positioning block is hollow, and the bottom positioning block is provided with a placement groove. The bottom surface of the placement groove is arc-shaped, and both side edges are smooth sections; the edge of the side positioning block is provided with a plurality of fixing holes.

2. The high-precision processing method of a double convex cylindrical surface according to claim 1, characterized in that: In step (3), a precision engraving machine is used to process the top and bottom contours of the blank mirror and the inner contour of the positioning fixture to a flatness of 5 microns.

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