Central Punching Process for Infrared Aspherical Lenses

Abstract

A central hole drilling process for an infrared aspherical lens includes the following steps: Step 1, install a diamond tool on a tool holder; Step 2, fix the infrared aspherical lens on a lens fixing seat, and the lens fixing seat is fixed on an air spindle by vacuum adsorption, with a rotational speed around the axial direction of the air spindle being 2000 - 5000 RPM and a translational speed along the radial direction being 5 mm - 10 mm / min; Step 3, set a chamfer; Step 4, set turning parameters, with the feed per cut of the diamond tool being 0.01 mm - 0.2 mm; Step 5, drill the first hole according to the turning parameters in Step 2 to Step 4, and the depth of the first hole is 30 - 40% of the hole depth; Step 6, after the first hole drilling is completed, the infrared aspherical lens is reversed by 180 degrees; Step 7, drill the second hole according to the turning parameters in Step 2 to Step 4 to drill through the hole; Step 8, finish machining the chamfered part on one side of the drilled-through hole, then reverse the infrared aspherical lens by 180 degrees, and then finish machining the chamfered part on one side again to repair the cylindricity of the hole.

Description

Technical Field

[0001] The present disclosure relates to the field of infrared aspherical lenses, and more particularly to a central punching process for infrared aspherical lenses. Background Art

[0002] Due to special requirements in the optical path, some infrared lenses such as germanium and silicon need to have a through hole in the center of the lens to meet the optical design requirements, which requires punching a hole in the center of the infrared lens during processing.

[0003] In the past traditional processing technology, after the infrared lens surface profile was processed, a perforating machine was used for perforation; the biggest problem with this method is that it cannot guarantee concentricity while increasing the internal stress of the aspherical lens, resulting in edge cracking and affecting the imaging effect of the lens; it has always been a difficult problem to solve. Summary of the Invention

[0004] In view of the problems existing in the background art, one object of the present disclosure is to provide a central punching process for infrared aspherical lenses, which can avoid the risk of edge cracking of the hole during punching.

[0005] In view of the problems existing in the background art, another object of the present disclosure is to provide a central punching process for infrared aspherical lenses, which can guarantee the accuracy of the aperture diameter.

[0006] In view of the problems existing in the background art, another object of the present disclosure is to provide a central punching process for infrared aspherical lenses, which can guarantee the concentricity of the aperture diameter.

[0007] Accordingly, a center drilling process for an infrared aspherical lens includes the following steps: Step 1, install a diamond tool on the tool holder of a single-point diamond precision turning machine; Step 2, fix the infrared aspherical lens with the surface machining completed on a lens fixing seat, and the lens fixing seat is fixed to the air spindle of the single-point diamond precision turning machine by vacuum adsorption. The axis of the air spindle passes through the center of the infrared aspherical lens. The air spindle is installed on the motor of the single-point diamond precision turning machine. The motor can drive the air spindle together with the lens fixing seat and the infrared aspherical lens to rotate around the axis of the air spindle, and the motor, the air spindle together with the lens fixing seat and the infrared aspherical lens can translate radially. The rotation speed around the axis of the air spindle is 2000 - 5000 RPM, and the translation speed in the radial direction is 5 mm - 10 mm / min; Step 3, set the chamfers at the convex and concave surfaces of the infrared aspherical lens according to the aperture of the hole drilled in the center of the infrared aspherical lens; Step 4, set the turning parameters of the diamond tool of the single-point diamond precision turning machine. The diamond tool advances relative to the infrared aspherical lens along the axis of the air spindle by 0.01 mm - 0.2 mm each time under the drive of the tool holder, and determine the number of feedings according to the hole depth; Step 5, drill the center of the infrared aspherical lens for the first time according to the turning parameters in Step 2 to Step 4. The depth of the first drilling is 30 - 40% of the hole depth; Step 6, after the first drilling is completed, adjust the lens fixing seat to reverse the infrared aspherical lens by 180 degrees, and then fix the lens fixing seat to the air spindle of the single-point diamond precision turning machine by vacuum adsorption again, so that the diamond tool drills from the other surface of the infrared aspherical lens opposite to the surface after the first drilling; Step 7, perform the second drilling according to the turning parameters in Step 2 to Step 4 to drill through the hole; Step 8, perform fine machining on the chamfered part of the drilled hole on the other surface. After the fine machining of the chamfered part on the other surface is completed, adjust the lens fixing seat to reverse the infrared aspherical lens by 180 degrees, and then fix the lens fixing seat to the air spindle of the single-point diamond precision turning machine by vacuum adsorption again, and then perform fine machining on the chamfered part on one surface. After the fine machining of the chamfered part on one surface is completed, repair the cylindricity of the hole.

[0008] The beneficial effects of the present disclosure are as follows: In the central hole drilling process of the infrared aspherical lens of the present disclosure, a single-point diamond precision turning machine tool and a matching diamond tool are used to turn a hole at the center of the infrared aspherical lens. The contact between the diamond tool and the infrared aspherical lens is single-point or near single-point. Then, with a feed rate of 0.01 mm - 0.2 mm each time, a translation speed along the radial direction X of 5 mm - 10 mm / min, and a rotation speed around the air spindle along the axial direction Z of 2000 - 5000 RPM, the formation of the hole reaches high precision. By using a feed rate of 0.01 mm - 0.2 mm each time and a translation speed along the radial direction X of 5 mm - 10 mm / min, while ensuring the precision, it can reduce the damage to the infrared aspherical lens (especially in the case where the infrared aspherical lens is an infrared crystal aspherical lens. The infrared crystal aspherical lens has characteristics such as softness, high brittleness, sensitivity to temperature changes, and easy cracking, which are not easy to process). By repairing the cylindricity of the hole in step eight, the concentricity of the hole diameter is ensured. By drilling from the opposite two sides of the infrared aspherical lens in steps five to seven and the depth of the first drilling is 30 - 40% of the hole depth, on the one hand, it can simplify the design of the diamond tool (because the drilling is not completed at one time), and on the other hand, the part where the hole penetrates is inside the center of the infrared aspherical lens rather than at one of the outer surfaces (convex surface or concave surface) of the center of the infrared aspherical lens. This is very beneficial in the case where the infrared aspherical lens is an infrared crystal aspherical lens because the infrared crystal aspherical lens has characteristics such as softness, high brittleness, sensitivity to temperature changes, and easy cracking. If a one-time drilling is used, the part where the hole penetrates will be on one of the outer surfaces (convex surface or concave surface) of the center of the infrared aspherical lens, which is likely to cause a risk of cracking at the circumference of the part where the hole penetrates, thus not only affecting the yield rate but also greatly increasing the repair difficulty. In addition, since the chamfer is in the form of a slope, it will be formed by forming holes with different diameters in the previous several feedings. Due to the single-point or near single-point contact between the diamond tool and the infrared aspherical lens, the chamfer formed after the first drilling and the second drilling can be closer to the slope surface of the final chamfer, which is beneficial to reducing the workload of the finish machining in step eight. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a three-dimensional view of the diamond tool used in the central hole drilling process of the infrared aspherical lens according to the present disclosure.

[0010] Figure 2 is Figure 1 a three-dimensional view from another angle of

[0011] Figure 3 is Figure 1 a three-dimensional view from yet another angle of

[0012] Figure 4 is Figure 1 the front view of.

[0013] Figure 5 is a schematic diagram of a lens fixing base and an air spindle.

[0014] Figure 6 is an exploded view of the lens fixing base, in which the infrared aspherical lens is schematically shown.

[0015] Figure 7 is an exploded view of the lens fixing base from another angle, in which the infrared aspherical lens is schematically shown.

[0016] Figure 8 is a perspective view observed from the concave side of the infrared aspherical lens after the center punching process of the infrared aspherical lens according to the present disclosure.

[0017] Figure 9 is from Figure 8 the opposite convex surface of, where the top surface of the infrared aspherical lens is marked on the convex surface to correspond to Figure 6 and Figure 7 correspondingly.

[0018] Wherein, the reference numerals are explained as follows:

[0019] 1000 diamond cutting tool 31 finger part

[0020] 1000a main cutting edge 311 step part

[0021] 2000 infrared aspherical lens 311a lying surface

[0022] 2000a bottom surface 311b vertical surface

[0023] 2000b side surface 312 outer wall surface

[0024] 2000c top surface 200 cap body

[0025] 3000 lens fixing base 200a first inner circumferential surface

[0026] 100 seat body 200b second inner conical circumferential surface

[0027] 1 air spindle connection part 200c opening

[0028] 2 cap body connection part 200d internal thread

[0029] 21 external thread 4000 air spindle

[0030] 3 lens support part Z axial direction

[0031] X radial direction Detailed implementation manners

[0032] The accompanying drawings illustrate embodiments of the present disclosure, and it will be understood that the disclosed embodiments are merely examples of the present disclosure, and the present disclosure can be implemented in various forms. Therefore, the specific details disclosed herein should not be construed as limiting, but only as a basis for the claims and as a representative basis for teaching those of ordinary skill in the art to implement the present disclosure in various ways.

[0033] Referring to Figures 1 to 9 , the central hole punching process of the infrared aspherical lens according to the present disclosure includes the steps of:

[0034] Step 1, install the diamond tool 1000 on the tool holder (not shown) of the single-point diamond precision turning machine.

[0035] Step 2, fix the infrared aspherical lens 2000 with the completed surface machining on the lens fixing seat 3000. The lens fixing seat 3000 is fixed on the air spindle 4000 of the single-point diamond precision turning machine by vacuum adsorption. The axis Z of the air spindle 4000 passes through the center of the infrared aspherical lens. The air spindle 4000 is installed on the motor (not shown) of the single-point diamond precision turning machine. The motor can drive the air spindle together with the lens fixing seat 3000 and the infrared aspherical lens 2000 to rotate around the axis Z of the air spindle 4000, and the motor, the air spindle 4000 together with the lens fixing seat 3000 and the infrared aspherical lens 2000 can translate along the radial direction X. The rotation speed around the axis Z of the air spindle 4000 is 2000 - 5000 RPM, and the translation speed along the radial direction X is 5 mm - 10 mm / min.

[0036] Step 3, set the chamfers at both the convex and concave surfaces of the infrared aspherical lens 2000 according to the aperture of the hole punched in the center of the infrared aspherical lens 2000.

[0037] Step 4, set the turning parameters of the diamond tool 1000 of the single-point diamond precision turning machine. The diamond tool 1000 advances relative to the infrared aspherical lens 2000 along the axis Z of the air spindle 4000 by 0.01 mm - 0.2 mm each time under the drive of the tool holder, and determine the number of feedings according to the hole depth.

[0038] Step 5, punch the center of the infrared aspherical lens 2000 for the first time according to the turning parameters of Step 2 to Step 4. The depth of the first punching is 30 - 40% of the hole depth.

[0039] Step 6, after the first drilling is completed, adjust the lens holder 3000 to reverse the infrared aspherical lens by 180 degrees, and then vacuum-adsorb and fix the lens holder 3000 on the air spindle 4000 of the single-point diamond precision turning machine, so that the diamond tool 1000 drills a hole from the other surface of the infrared aspherical lens 2000, which is opposite to the surface after the first drilling;

[0040] Step 7, perform the second drilling according to the turning parameters in Steps 2 to 4 to drill through the hole;

[0041] Step 8, perform finish machining on the chamfered part of the drilled hole on the other surface. After the finish machining of the chamfered part on the other surface is completed, adjust the lens holder 3000 to reverse the infrared aspherical lens 2000 by 180 degrees, and then vacuum-adsorb and fix the lens holder 3000 on the air spindle 4000 of the single-point diamond precision turning machine, and then perform finish machining on the chamfered part on the one surface. After the finish machining of the chamfered part on the one surface is completed, repair the cylindricity of the hole.

[0042] In the central hole drilling process of the infrared aspherical lens of the present disclosure, a single-point diamond precision turning machine tool and a matching diamond tool 1000 are used to turn a hole at the center of the infrared aspherical lens 2000. The contact between the diamond tool 1000 and the infrared aspherical lens 2000 is single-point or near single-point. Then, with a feed rate of 0.01 mm - 0.2 mm each time, a translation speed along the radial direction X of 5 mm - 10 mm / min, and an axial Z rotation speed around the air spindle 4000 of 2000 - 5000 RPM, the formation of the hole reaches high precision. By using a feed rate of 0.01 mm - 0.2 mm each time and a translation speed along the radial direction X of 5 mm - 10 mm / min, while ensuring the precision, the damage to the infrared aspherical lens 2000 can be reduced (especially in the case where the infrared aspherical lens 2000 is an infrared crystal aspherical lens. The infrared crystal aspherical lens has characteristics such as softness, high brittleness, sensitivity to temperature changes, and easy cracking, which are not easy to process). By repairing the cylindricity of the hole in step eight, the concentricity of the hole diameter is ensured. By drilling holes from the opposite two sides of the infrared aspherical lens 2000 in steps five to seven and the depth of the first drilling is 30 - 40% of the hole depth, on the one hand, it can simplify the design of the diamond tool 1000 (because the drilling is not completed at one time), and on the other hand, the part where the hole penetrates is inside the center of the infrared aspherical lens 2000 rather than at one of the outer surfaces (convex surface or concave surface) of the center of the infrared aspherical lens 2000. This is very beneficial in the case where the infrared aspherical lens 2000 is an infrared crystal aspherical lens. Because the infrared crystal aspherical lens has characteristics such as softness, high brittleness, sensitivity to temperature changes, and easy cracking, which are not easy to process. If one-time drilling is used, the part where the hole penetrates will be on one of the outer surfaces (convex surface or concave surface) of the center of the infrared aspherical lens 2000, which is likely to cause a risk of cracking at the circumferential part where the hole penetrates, thus not only affecting the yield rate but also greatly increasing the repair difficulty. In addition, since the chamfer is in the form of a slope, it is formed by forming holes with different diameters in the previous several feedings during multiple feedings. Since the contact between the diamond tool 1000 and the infrared aspherical lens 2000 is single-point or near single-point, the chamfer formed after the first drilling and the second drilling can be closer to the slope surface of the final chamfer, which is beneficial to reducing the workload of the finish machining in step eight.

[0043] In step two, the infrared aspherical lens 2000 can be an infrared crystal aspherical lens. Further, the infrared crystal aspherical lens is a germanium, silicon, zinc sulfide, zinc selenide, gallium arsenide aspherical lens.

[0044] In step two, during the hole drilling of the diamond tool 1000, the main cutting edge 1000a (refer to Figure 1) has a tool offset angle of 25 - 45°. In this angle range, it is easy to break the chips formed by turning the infrared aspherical lens 2000 and facilitate chip evacuation, avoiding the risk of chip scratching the infrared aspherical lens 2000 caused by too large or too small tool offset angles. Preferably, in step two, the tool offset angle of the main cutting edge 1000a of the diamond tool 1000 during drilling is 45°. In step two, the diamond tool 1000 can be a commercially available diamond tool, such as the diamond tool manufactured and sold by Shenzhen Yuhe Optical Precision Tool Co., Ltd.

[0045] In addition, since the contact between the main cutting edge 1000a of the diamond tool 1000 and the infrared aspherical lens 2000 is single-point or near single-point, the edge radius of the main cutting edge 1000a is 0.2 μm - 0.7 μm.

[0046] In one embodiment, in step two, referring to Figure 6 and Figure 7 , the lens fixing base 3000 includes a base body 100 and a cap body 200. The base body 100 includes an air spindle connection portion 1, a cap body connection portion 2, and a lens support portion 3. The air spindle connection portion 1 is used to be fixedly adsorbed by vacuum on the air spindle 4000; the cap body connection portion 2 is located above the air spindle connection portion 1 (in the Figure 6 and Figure 7 posture) and is provided with an external thread 21; the lens support portion 3 is located above the cap body connection portion 2 (in the Figure 6 and Figure 7In the posture of (), the lens support portion 3 includes a plurality of finger portions 31. The plurality of finger portions 31 are circumferentially spaced apart from each other, capable of being radially forced to converge and radially expand after the release of force. A step portion 311 is provided on the inner side of the top of each finger portion 31. The step portion 311 has a flat lying surface 311a and a vertical surface 311b. The flat lying surface 311a is used to support a part of the bottom surface 2000a of the infrared aspherical lens 2000 to be drilled, and the vertical surface 311b is used to clamp a part of the side surface 2000b of the infrared aspherical lens 2000 to be drilled when the plurality of finger portions 31 are forced to converge; the cap body 200 has a first inner circumferential surface 200a, a second inner conical circumferential surface 200b, and an opening 200c; the first inner circumferential surface 200a is provided with an internal thread 200d, and the internal thread 200d is used for threaded cooperation with the external thread 21 of the cap body connecting portion 2 to fix the cap body 200 to the seat body 100; the second inner conical circumferential surface 200b protrudes radially inward from the first inner circumferential surface 200a and tapers from bottom to top. The second inner conical circumferential surface 200b is used to contact the outer wall surfaces 312 of the plurality of finger portions 31 of the lens support portion 3 of the seat body 100 so that when the internal thread 200d of the first inner circumferential surface 200a and the external thread 21 of the cap body connecting portion 2 are tightened from top to bottom for threaded cooperation, the plurality of finger portions 31 are radially forced to converge, and further the vertical surfaces 311b of the step portions 311 of the plurality of finger portions 31 clamp a part of the side surface 2000b of the infrared aspherical lens 2000 to be drilled; the opening 200c is used to expose a part of the top surface 2000c of the infrared aspherical lens 2000 for drilling with the diamond tool 1000. It should be noted here that the top surface 2000c is the convex surface or the concave surface of the infrared aspherical lens 2000. By clamping the side surface 2000b of the infrared aspherical lens 2000 to be drilled with the vertical surfaces 311b of the step portions 311 of the plurality of finger portions 31, the position of the infrared aspherical lens 2000 can be guaranteed, whether the top surface 2000c is the convex surface or the concave surface of the infrared aspherical lens 2000.

[0047] In step two, any suitable means can be adopted to enable the motor, the air spindle 4000, together with the lens fixing seat 3000 and the infrared aspherical lens 2000 to translate radially along the X direction, such as well-known forms such as cylinders, hydraulic cylinders, linear motors, etc.

[0048] In step four, the single-point diamond precision turning machine is selected as the DJC-100A ultra-precision single-point diamond lathe of Beijing Hepurishen Ultra-Precision Technology Co., Ltd. Specifically, except for the lens fixing seat 3000 and the diamond tool 1000, the tool holder, the air spindle 4000, the motor, and any suitable means that can enable the motor, the air spindle 4000, together with the lens fixing seat 3000 and the infrared aspherical lens 2000 to translate radially along the X direction, etc. are all components of the DJC-100A ultra-precision single-point diamond lathe itself.

[0049] In step four, when the thickness at the center of the punching position of the infrared aspherical lens 2000 is 8.5 mm - 10 mm, the feed per tooth of the diamond tool 1000 is 0.15 mm - 0.2 mm; when the thickness at the center of the punching position of the infrared aspherical lens 2000 is 1.2 mm - 2.0 mm, the feed per tooth of the diamond tool 1000 is 0.01 mm - 0.05 mm. Further, in step four, when the thickness at the center of the punching position of the infrared aspherical lens 2000 is 8.5 mm - 10 mm, the feed per tooth of the diamond tool 1000 is 0.15 mm; when the thickness at the center of the punching position of the infrared aspherical lens 2000 is 1.2 mm - 2.0 mm, the feed per tooth of the diamond tool 1000 is 0.01 mm.

[0050] In step five, the infrared aspherical lens 2000 is punched for the first time, and the depth of the first punching is two-fifths of the hole depth. This makes the first punching closer to the middle of the thickness at the center of the infrared aspherical lens 2000 but with a certain margin left.

[0051] Multiple exemplary embodiments are described with the above detailed description, but the present disclosure is not intended to be limited to the explicitly disclosed combinations. Thus, unless otherwise stated, the various features disclosed herein may be combined together to form multiple additional combinations not shown for the sake of brevity.

Claims

1. A central hole drilling process for an infrared aspherical lens, characterized in that, it includes the steps: Step 1, install the diamond tool (1000) on the tool holder of a single-point diamond precision turning machine; Step 2, fix the infrared aspherical lens (2000) with the surface machining completed on the lens fixing seat (3000). The lens fixing seat (3000) is fixed on the air spindle (4000) of the single-point diamond precision turning machine by vacuum adsorption. The axis (Z) of the air spindle (4000) passes through the center of the infrared aspherical lens. The air spindle (4000) is installed on the motor of the single-point diamond precision turning machine. The motor can drive the air spindle together with the lens fixing seat (3000) and the infrared aspherical lens (2000) to rotate around the axis (Z) of the air spindle (4000), and the motor, the air spindle (4000) together with the lens fixing seat (3000) and the infrared aspherical lens (2000) can translate along the radial direction (X). The rotation speed around the axis (Z) of the air spindle (4000) is 2000 - 5000 RPM, and the translation speed along the radial direction (X) is 5 mm - 10 mm / min; Step 3, set the chamfers at the convex and concave surfaces of the infrared aspherical lens (2000) according to the aperture of the hole drilled in the center of the infrared aspherical lens (2000); Step 4, set the turning parameters of the diamond tool (1000) of the single-point diamond precision turning machine. The diamond tool (1000) advances relative to the infrared aspherical lens (2000) along the axis (Z) of the air spindle (4000) by 0.01 mm - 0.2 mm each time under the drive of the tool holder, and determine the number of feedings according to the hole depth; Step 5, perform the first drilling on the center of the infrared aspherical lens (2000) according to the turning parameters of Step 2 to Step 4. The depth of the first drilling is 30 - 40% of the hole depth; Step 6, after the first drilling is completed, adjust the lens fixing seat (3000) to reverse the infrared aspherical lens by 180 degrees, and then fix the lens fixing seat (3000) on the air spindle (4000) of the single-point diamond precision turning machine by vacuum adsorption, so that the diamond tool (1000) drills from the other surface of the infrared aspherical lens (2000) opposite to the surface after the first drilling; Step 7, perform the second drilling according to the turning parameters of Step 2 to Step 4 to drill through the hole; Step 8, perform finish machining on the chamfered part of the hole on the other surface. After the finish machining of the chamfered part on the other surface is completed, adjust the lens fixing seat (3000) to reverse the infrared aspherical lens (2000) by 180 degrees, and then fix the lens fixing seat (3000) on the air spindle (4000) of the single-point diamond precision turning machine by vacuum adsorption, and then perform finish machining on the chamfered part on one surface. After the finish machining of the chamfered part on one surface is completed, repair the cylindricity of the hole.

2. The central hole drilling process for an infrared aspherical lens according to claim 1, characterized in that, In step two, the infrared aspherical lens (2000) is an infrared crystal aspherical lens.

3. The central punching process of the infrared aspherical lens according to claim 2, characterized in that the infrared crystal aspherical lens is a germanium, silicon, zinc sulfide, zinc selenide, gallium arsenide aspherical lens.

4. The central punching process of the infrared aspherical lens according to claim 1, characterized in that in step two, the tool offset of the main cutting edge (1000a) of the diamond tool (1000) during punching is 25 - 45° angle.

5. The central punching process of the infrared aspherical lens according to claim 4, characterized in that in step two, the tool offset of the main cutting edge 1000a) of the diamond tool (1000) during punching is 45° angle.

6. The central punching process of the infrared aspherical lens according to claim 4, characterized in that in step two, the edge radius of the main cutting edge (1000a) of the diamond tool (1000) is 0.2μm - 0.7μm.

7. The central punching process of the infrared aspherical lens according to claim 1, characterized in that in step two, the lens fixing base (3000) includes a base body (100) and a cap body (200), the base body (100) includes an air spindle connection part (1), a cap body connection part (2) and a lens support part (3); the air spindle connection part (1) is used to be vacuum - adsorbed and fixed on the air spindle (4000); the cap body connection part (2) is located above the air spindle connection part (1) and is provided with an external thread (21); the lens support part (3) is located above the cap body connection part (2). The lens support part (3) includes a plurality of finger parts (31). The plurality of finger parts (31) are circumferentially spaced apart from each other, can be radially forced to close and radially expand after releasing the force. The inner side of the top of each finger part (31) is provided with a step part (311). The step part (311) has a flat surface (311a) and a vertical surface (311b). The flat surface (311a) is used to support a part of the bottom surface (2000a) of the infrared aspherical lens (2000) to be punched, and the vertical surface (311b) is used to clamp a part of the side surface (2000b) of the infrared aspherical lens (2000) to be punched when the plurality of finger parts (31) are forced to close; the cap body (200) has a first inner circumferential surface (200a), a second inner conical circumferential surface (200b) and an opening (200c); the first inner circumferential surface (200a) is provided with an internal thread (200d). The internal thread (200d) is used for thread - matching with the external thread (21) of the cap body connection part (2) to fix the cap body (200) on the base body (100); The second inner conical peripheral surface (200b) projects radially inwards from the first inner circumferential surface (200a) and tapers from bottom to top. The second inner conical peripheral surface (200b) is used to contact the outer wall surfaces (312) of the plurality of fingers (31) of the lens support portion (3) of the seat body (100) so that when the internal thread (200d) of the first inner circumferential surface (200a) and the external thread (21) of the cap body connecting portion (2) are screwed together from top to bottom, the plurality of fingers (31) are radially forced to contract, and further, the vertical surfaces (311b) of the stepped portions (311) of the plurality of fingers (31) clamp the side surface (2000b) of the infrared aspherical lens (2000) to be drilled; The opening (200c) is used to expose a part of the top surface (2000c) of the infrared aspherical lens (2000) for drilling by the diamond cutter (1000).

8. The central drilling process of the infrared aspherical lens according to claim 1, characterized in that, in step four, when the thickness at the center of the drilling position of the infrared aspherical lens (2000) is 8.5 mm - 10 mm, the feed per tooth of the diamond cutter (1000) is 0.15 mm - 0.2 mm; when the thickness at the center of the drilling position of the infrared aspherical lens (2000) is 1.2 mm - 2.0 mm, the feed per tooth of the diamond cutter (1000) is 0.01 mm - 0.05 mm.

9. The central drilling process of the infrared aspherical lens according to claim 8, characterized in that, in step four, when the thickness at the center of the drilling position of the infrared aspherical lens (2000) is 8.5 mm - 10 mm, the feed per tooth of the diamond cutter (1000) is 0.15 mm; when the thickness at the center of the drilling position of the infrared aspherical lens (2000) is 1.2 mm - 2.0 mm, the feed per tooth of the diamond cutter (1000) is 0.01 mm.

10. The central drilling process of the infrared aspherical lens according to claim 1, characterized in that, in step five, the infrared aspherical lens (2000) is drilled for the first time, and the depth of the first drilling is two-fifths of the hole depth.

Images