Optical cold working method for an elongated columnar lens

Abstract

This application provides an optical cold processing method for slender cylindrical lenses, comprising the steps of: providing an optical blank with a predetermined outer circular standard size; machining the first end of the optical blank into a first reference surface to obtain a first part; providing a first centering clamping fixture, using the first reference surface as a positioning reference, to clamp the outer circle of the first part, wherein the first part is automatically centered during clamping; machining the second end of the first part into a spherical surface to obtain a second part; detecting that the center height of the second part reaches the predetermined center height standard; providing a second centering clamping fixture, clamping the outer circle of the second part; machining the first end of the second part into a conical surface to obtain a finished part; and detecting that the center height of the finished part reaches the predetermined center height standard. This method solves the problem in the prior art of large center deviations during the processing of slender cylindrical optical components, making it impossible to accurately control various optical parameters.

Description

Technical Field

[0001] This application relates to the field of optical component processing technology, and more specifically, to an optical cold processing method for slender cylindrical lenses. Background Technology

[0002] Existing slender cylindrical optical components require high dimensional accuracy. For example, pencil lenses have a slender rod with a spherical and a conical surface at each end. The center height and surface quality of the spherical and conical surfaces have high requirements.

[0003] In existing processing methods, the polishing of such slender cylindrical optical components usually involves bonding a mold and then adding adhesive dots to the plate. This processing method can only ensure that the center deviation is within a relatively large range, which makes it difficult to effectively limit the center deviation during the processing. In addition, it is time-consuming and cannot accurately control various optical indicators.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] The purpose of this application is to provide an optical cold processing method for slender cylindrical lenses, which solves the problem that the center deviation of slender cylindrical optical components is large during the processing of existing technologies, and that it is impossible to accurately control various optical indicators.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] This application provides an optical cold processing method for slender cylindrical lenses, including the following steps:

[0008] An optical blank with a predetermined outer diameter is provided, and the first end of the optical blank is machined into a first reference surface to obtain a first part;

[0009] A first centering clamping fixture is provided, which uses a first reference plane as a positioning reference to clamp the outer circle of a first part, wherein the first part is automatically centered during the clamping process;

[0010] The second end of the first part is machined into a spherical surface to obtain the second part. The center height of the second part is then checked to ensure it meets the predetermined center height standard.

[0011] A second centering clamping fixture is provided to clamp the outer circle of the second part and to machine the first end of the second part into a tapered surface to obtain the finished part;

[0012] The center height of the finished part is checked to ensure it meets the predetermined center height standard.

[0013] In an optional embodiment, the step of providing an optical blank with a predetermined outer diameter standard size and machining a first end of the optical blank into a first reference surface to obtain a first part includes:

[0014] The optical blank is fixed on the optical adhesive plate, and the end face of the first end of the optical blank is ground to the predetermined size.

[0015] The end face after grinding is polished to form the first reference surface.

[0016] In an optional embodiment, after the step of polishing the ground end face to form the first reference surface, the method further includes:

[0017] Using the first reference plane as the positioning reference, the outer circle of the second end of the first part is polished to achieve the predetermined polishing quality.

[0018] In an optional embodiment, a first centering clamping fixture is provided, using a first reference plane as a positioning reference, to clamp the outer circle of a first part, wherein the step of automatically centering the first part during clamping includes:

[0019] The first centering clamping fixture includes a column and a bearing cylinder. The column is provided with a receiving hole, and the bearing cylinder is sleeved on the column. The end of the column facing the opening of the receiving hole is provided with an expansion part, which includes a plurality of clamping blocks arranged at intervals around the central axis of the receiving hole.

[0020] By twisting the bearing cylinder to move it along the axial direction of the column, the expanded part is squeezed and multiple clamping blocks are synchronously brought closer to the center of the receiving hole, so as to automatically center and clamp the first part.

[0021] In an optional embodiment, a first centering clamping fixture is provided, using a first reference plane as a positioning reference, to clamp the outer circle of a first part, wherein the step of automatically centering the first part during clamping includes:

[0022] Fix the first centering clamping fixture to the first processing equipment;

[0023] The first part is inserted into the receiving hole of the first centering clamping fixture and positioned by the bottom surface of the receiving hole abutting against the first reference surface, so that the second end of the first part is exposed.

[0024] By twisting the bearing cylinder fitted on the column, the bearing cylinder moves along the axial direction of the column. The inner wall of the bearing cylinder is squeezed and expanded, and the squeezed and expanded part causes multiple clamping blocks to move synchronously toward the center of the receiving hole.

[0025] In an optional embodiment, in the step of machining the second end of the first part into a spherical surface to obtain the second part, and detecting that the center height of the second part reaches a predetermined center height standard:

[0026] The second end face of the first part is processed by the first processing equipment to obtain a frosted spherical surface;

[0027] Polish the frosted spherical surface to obtain the finished spherical surface.

[0028] In an optional embodiment, the step of machining the second end of the first part into a spherical surface to obtain the second part, and detecting that the center height of the second part reaches a predetermined center height standard, further includes:

[0029] After the second part is placed on the inspection and positioning fixture, the center height of the second part is checked to ensure that it reaches the predetermined center height standard.

[0030] The detection and positioning fixture includes: a bottom parallel window piece, a first side square piece, and a second side square piece. The first side square piece and the second side square piece are both perpendicular to the bottom parallel window piece, and the first side square piece and the second side square piece are perpendicular to each other. The bottom parallel window piece, the first side square piece, and the second side square piece form a positioning space.

[0031] The second part is placed vertically against the inner wall of the positioning space, and the center height of the second part is determined by detecting the height of the second part.

[0032] In an optional embodiment, in the step of providing a second centering clamping fixture to clamp the outer circle of the second part and machining the first end of the second part into a tapered surface to obtain the finished part:

[0033] The second centering clamping fixture includes: a fixture base, an elastic sleeve, and a sleeve nut. The fixture base has a tapered positioning hole, the elastic sleeve is used to be installed in the tapered positioning hole, the elastic sleeve has a central shaft hole, and the sleeve nut is sleeved on the elastic sleeve and screwed onto the fixture base.

[0034] The central hole of the elastic sleeve is used to insert the second part. By tightening the sleeve nut, the elastic sleeve is compressed and deformed to clamp the second part.

[0035] In an optional embodiment, the step of providing a second centering clamping fixture to hold the outer circle of the second part and machining the first end of the second part into a tapered surface to obtain the finished part includes:

[0036] Fix the tooling base to the second processing equipment, and use a dial indicator to adjust the eccentricity between the second centering clamping tool and the spindle of the second processing equipment to achieve the predetermined coaxiality requirement;

[0037] Insert the second part into the central hole of the elastic sleeve, so that the first end of the second part is exposed;

[0038] By tightening the nut on the tooling base, the elastic sleeve clamps the outer circle of the second part.

[0039] The first end of the second part is milled into a conical surface using a second processing device.

[0040] In an optional embodiment, in the step of detecting that the center height of the finished part reaches a predetermined center height standard:

[0041] The outer diameter of the finished part is pressed against the inner wall of the inspection and positioning fixture;

[0042] The center height of the finished part is measured using a test table after calibration with a standard block.

[0043] The beneficial effects of the optical cold processing method for slender cylindrical lenses provided in this application are at least as follows: First, a first part with a first reference surface is machined from the first end of the blank. Then, the first part is clamped by a first centering fixture. During the clamping process, the first reference surface is used for positioning to ensure the height dimension of the processed part. Furthermore, the first centering fixture automatically centers the first part during clamping, thereby ensuring that the center deviation of the first part during processing is controlled, resulting in a second part that meets the center deviation requirements and has a spherical surface. After detecting that the center height of the second part reaches the predetermined center height standard, the outer circle of the second part is clamped by a second centering fixture. During the clamping process, the second centering fixture automatically centers the second part, and the first end of the second part is machined into a conical surface to obtain the finished part. After detecting that the center height of the finished part reaches the predetermined center height standard, the processing of the entire optical component is completed. This optical cold processing method, through the automatic centering and clamping of the first and second centering fixtures, efficiently processes the spherical end face and conical surface of slender parts and ensures stable control of optical indicators. The invention employs a specially designed flexible tooling method that offers better stability, enables higher precision control over the product's center deviation, and provides more accurate positioning of the product. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the structure of the finished part according to an embodiment of this application;

[0046] Figure 2A flowchart illustrating the main steps of an optical cold processing method for a slender cylindrical lens provided in this application embodiment;

[0047] Figure 3 A flowchart illustrating the detailed steps of an optical cold processing method for a slender cylindrical lens provided in this application embodiment;

[0048] Figure 4 This is a schematic diagram of the structure of the first part during processing in an optical cold processing method for a slender cylindrical lens provided in an embodiment of this application;

[0049] Figure 5 An exploded view of the first part connected to the first centering clamping fixture, provided in an embodiment of this application;

[0050] Figure 6 A cross-sectional view of the first centering clamping fixture provided in the embodiments of this application when the first part is extracted;

[0051] Figure 7 A cross-sectional view from another perspective of the first centering clamping fixture provided in the embodiments of this application when clamping and fixing the first part;

[0052] Figure 8 Exploded view of the first centering clamping fixture provided in the embodiments of this application after cross-section;

[0053] Figure 9 A schematic diagram of the structure of the detection and positioning fixture provided in this application embodiment when detecting a second part;

[0054] Figure 10 A cross-sectional view of the second centering clamping fixture provided in the embodiments of this application when it is not assembled;

[0055] Figure 11 This is a schematic diagram of the detection and positioning fixture provided in the embodiments of this application when detecting finished parts.

[0056] The following are the labeling elements in the figure:

[0057] 1. Finished part; 10. First part; 100. Base; 110. Locking platform; 200. Column; 210. Receiving hole; 211. Fixed section; 212. Intermediate section; 213. Fastening section; 220. Expanded part; 221. Clamping block; 222. Relief groove; 223. Frustum-shaped; 230. Column; 300. Bearing cylinder; 310. Pressing platform; 311. Conical inner wall; 320. Stop flange; 321. Mounting groove; 400. Matching plate; 410. Through hole; 20. Second part; 30. Inspection and positioning fixture; 31. Bottom parallel window piece; 32. First side square piece; 33. Second side square piece; 40. Second centering clamping fixture; 41. Fixture base; 42. Conical positioning hole; 43. Elastic sleeve; 44. Central shaft hole; 45. Sleeve nut. Detailed Implementation

[0058] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0059] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it may be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it may be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positions based on the accompanying drawings, and are for ease of description only, and should not be construed as limiting the technical solution. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0060] The specific definitions of the terms used in this application are as follows:

[0061] Lens: A lens is an optical element made of transparent material (such as glass, crystal, etc.).

[0062] Standard blocks: Standard blocks are high-precision measuring tools, typically defined by the distance between two parallel measuring surfaces to determine their working length. They are used to ensure that the dimensions of various finished products in machining are traceable to a length reference. The tolerance grade of standard blocks conforms to the international standard ISO 3650 and is suitable for high-precision measurement and calibration instruments.

[0063] Center deviation: Center deviation refers to the difference in distance between the actual optical axis and the theoretical optical axis of an optical lens, which is usually caused by errors in the manufacturing and assembly process of the lens.

[0064] Slender parts: Parts whose length to thickness or diameter to thickness ratio is greater than 8:1.

[0065] Edge thickness difference Δt: The difference in thickness at the edge of the lens is called the edge thickness difference.

[0066] Glossiness B: Glossiness refers to the smoothness and brightness of an object's surface. It mainly describes the smoothness of the surface and its ability to reflect light.

[0067] Coaxiality: Coaxiality is a positioning tolerance; the theoretically correct position is the datum axis. Since differences between the measured axis and the datum axis may occur in various directions in space, its tolerance zone is a cylinder with the datum axis as its axis. The tolerance value is the diameter of this cylinder, always preceded by the symbol "Φ".

[0068] Surface shape: PV (Peak to Valley), also known as peak-to-valley value, is a common indicator of the surface shape quality of optical surfaces. It refers to the height difference between the highest and lowest points within a sampling range (based on 2D contour lines or 3D data maps), after removing the reference surface. PV values ​​are expressed in units of physical length, and their meaning is easy to understand. Based on the required reference surface, the maximum deviation range of all pixels directly reflects the current processing quality of the optical surface. Based on long-term experience in optical testing, PV values ​​and another important surface shape indicator, RMS, often maintain a certain proportional relationship, generally around 2:1.

[0069] like Figure 1 As shown, the existing quality requirements for slender cylindrical optical components, such as a pencil-shaped lens (finished part 1), include: a lens size of Φ8mm×72mm; a polished spherical end face shape requirement of ΔN≤0.4fr and a radius of curvature SR25; a conical end face shape requirement of PV<lambda / 8@633nm; a conical end face diameter of Φ1±0.5mm; a conical end face coaxiality <0.02mm relative to the optical axis; a center deviation Creflection (center deviation measured by reflection) <20′; and a surface finish B=Ⅰ. For the processing of the above parts, the traditional method of using a bonding mold and then applying adhesive dots to the mounting plate often results in the product tilting during bonding, leading to insufficient center deviation. This uncontrollable center deviation results in a coaxiality greater than 0.02mm and a center deviation Creflection (center deviation measured by reflection) greater than 20′. This fails to meet the processing requirements of the part and also affects other optical indicators, resulting in substandard product quality.

[0070] Therefore, to solve or improve the above problems, experiments were conducted on three influencing factors: polishing method, special shape, and model design. The experiments analyzed and compared different polishing methods for rapidly processing spherical surfaces of elongated lens products, processing specific cone angles of elongated lens products, and setting up inspection fixtures. Through analysis and comparison, the polishing method and processing conditions that can meet the requirements of efficient processing were determined, thus forming the embodiments of this application, solving the optical processing problems of elongated lenses. The following embodiments are proposed in this application:

[0071] For ease of description, the end with the conical surface is designated as the first end, and the end with the spherical surface as the second end. The structural description of semi-finished parts at different stages obtained after each step in the finished part forming process is based on this standard.

[0072] Please see Figure 2 This embodiment proposes an optical cold processing method for slender cylindrical lenses, which mainly includes the following steps:

[0073] Step S100: Provide an optical blank with a predetermined outer diameter standard size, and process the first end of the optical blank into a first reference surface to obtain the first part.

[0074] In the specific process, the optical blank is cylindrical, and the outer diameter of the cylinder is pre-machined to match the overall outer diameter of the product, meeting the predetermined standard outer diameter requirements of the finished product. Therefore, the outer diameter of the optical blank does not need to be further processed. The outer diameter of the provided optical blank is first inspected using an image analyzer or micrometer to ensure that the dimensions of the optical blank meet the standard requirements before subsequent processing is carried out to create the first reference surface.

[0075] Please see Figure 2 , Figure 3 Step S100 specifically includes steps S110-S130, as follows:

[0076] Step S110: Fix the optical blank onto the optical adhesive plate and grind the end face of the first end of the optical blank to the predetermined size.

[0077] Step S120: Polish the ground end face to form the first reference surface.

[0078] In the above steps, multiple cylindrical optical blanks are coated with adhesive and then fixed with wax. The first end is ground using a single-axis grinding machine, controlling the height dimension to a positive tolerance, which is 0.1mm larger than the standard dimension. A polishing machine then polishes the ground end face to form a first reference surface. During polishing, the surface shape of the first reference surface needs to be inspected to ensure the optical parameters meet the surface shape standard requirements. After the first reference surface is processed, it needs to be removed from the plate, cleaned, and its surface finish inspected. Once the surface finish meets the standard requirements, the next step is performed.

[0079] For some optical components, where the surface shape parameters on the outer circumference are more critical, an additional outer circumference polishing process can be added. This process may also include:

[0080] Step S130: Using the first reference plane as the positioning reference, polish the outer circle of the second end of the first part to achieve the predetermined polishing quality.

[0081] During this process, since the optical component has higher requirements for the surface parameters of the outer circle around the sphere, the first part is clamped on a 4-axis polishing machine, and the outer diameter of the second end of the first part is polished with the first reference surface as the positioning reference to meet the product quality requirements.

[0082] Please see Figure 2 Step S200: Provide a first centering clamping fixture, using the first reference surface as the positioning reference, to clamp the outer circle of the first part, wherein the first part is automatically centered during the clamping process.

[0083] During the end face processing of this slender first part, the first part needs to be vertically positioned and then polished continuously using a polishing mold. If it is not firmly fixed, the first part will shake back and forth under the action of the polishing mold, which makes it difficult to control the center deviation Canti of the spherical end face to be less than 20′. Therefore, this first centering clamping fixture is used to ensure the center deviation Canti of the slender lens part, and a polishing device with a uniform upper swing is used to improve the spherical processing efficiency.

[0084] Please see Figure 4 , Figure 5The first centering clamping fixture in this embodiment includes a column 200 and a support cylinder 300. The column 200 is provided with a receiving hole 210, and the support cylinder 300 is sleeved on the column 200. One end of the column 200 facing the opening of the receiving hole 210 is provided with an expansion portion 220. The expansion portion 220 includes a plurality of clamping blocks 221 arranged at intervals around the central axis of the receiving hole 210. By twisting the support cylinder 300 to move it axially along the column 200, the expansion portion 220 is compressed, causing the plurality of clamping blocks 221 to move synchronously toward the center of the receiving hole 210, thereby automatically centering and clamping the first part 10.

[0085] In use, the first centering clamping fixture extends vertically from the column 200. Therefore, the end of the column 200 pointing upwards along its axial direction is considered the top end, and the end pointing downwards is considered the bottom end. The top end of the column 200 has a receiving hole 210, the opening of which faces upwards. The receiving hole 210 is a central hole used for inserting the first part 10. (See also...) Figure 4 The extension length of the column 200 matches the length of the first part 10 to be processed. When the first part 10 is inserted into the receiving hole 210, a portion of the first part 10 protrudes from the opening of the receiving hole 210. For example, the length protruding from the receiving hole 210 can be one-twentieth to one-quarter of the total length of the first part 10. Therefore, the protruding part accounts for a small portion of the total length of the first part 10, so that after fixing, the portion of the first part 10 exposed above the column 200 is relatively small, making the fixing more stable. The bearing cylinder 300 is sleeved on the column 200, and the bearing cylinder 300 extends axially, so that the column 200 is surrounded within the bearing cylinder 300, and the first part 10 protruding from the column 200 also protrudes from the top of the bearing cylinder 300, which facilitates the processing of the end face of the protruding first part 10. Please refer to [link to relevant documentation]. Figure 2 , Figure 3An expansion portion 220 is provided at one end of the column 200 facing the opening of the receiving hole 210. The expansion portion 220 includes a plurality of clamping blocks 221 arranged at intervals around the central axis of the receiving hole 210. The clamping blocks 221 can be evenly arranged around the central axis and are surrounded inside the support cylinder 300. By moving the support cylinder 300 along the axial direction of the column 200, the inner wall of the support cylinder 300 can squeeze or loosen the expansion portion 220. When the expansion portion 220 is squeezed by the support cylinder 300, the expansion portion 220 causes the plurality of clamping blocks 221 to move synchronously toward the center of the receiving hole 210 through the squeezing of the support cylinder 300, thereby making the opening formed by the plurality of clamping blocks 221 smaller to clamp the first part 10 located therein. When the expanding portion 220 is released by the bearing cylinder 300, the expanding portion 220 returns to its original position under its own elasticity, causing the multiple clamping blocks 221 to move away from the center of the receiving hole 210 synchronously. This enlarges the opening formed by the multiple clamping blocks 221, allowing the first part 10 located within it to be released. The synchronous convergence of the multiple clamping blocks 221 enables automatic centering of the clamped first part 10.

[0086] In this embodiment, by setting the column 200 vertically, the first part 10 can be inserted into the receiving hole 210. Then, the bearing cylinder 300 is sleeved on the column 200. As the bearing cylinder 300 moves downward, it squeezes the expanding part 220, so that multiple clamping blocks 221 can move towards the center of the receiving hole 210 simultaneously. In this way, the opening of the receiving hole 210 is narrowed by the synchronous inward movement of multiple clamping blocks 221, thereby clamping the first part 10. The vertically extending receiving hole 210 can stably surround the inserted first part 10 to be processed. By synchronously moving multiple clamping blocks 221 inward, the opening is narrowed, clamping the upper part of the first part 10. This not only makes the first part 10 more stable and prevents it from swaying back and forth under the influence of the polishing mold, but also achieves automatic centering during the clamping process, keeping the central axis of the first part 10 consistent with the central axis of the column 200. This improves the positioning accuracy of the first part 10. Especially after vertical positioning, during the continuous processing of the end face of the first part 10 by the polishing mold, it is less likely to produce center deviation, resulting in higher positioning accuracy. The center deviation of the optical first part 10 end face after polishing can be within 8 points.

[0087] Please see Figure 4 , Figure 5Furthermore, the column 200 in this embodiment also includes a column body 230, which extends vertically for a predetermined length. An expansion portion 220 is disposed at the top of the column body 230, and the outer diameter of the expansion portion 220 can be larger than the outer diameter of the column body 230. A pressing platform 310 is provided at the top of the bearing cylinder 300, and the inner wall of the pressing platform 310 abuts against the outer wall of the expansion portion 220. Setting the outer diameter of the expansion portion 220 to be relatively larger than that of the column body 230 facilitates the pressing platform 310 abutting against the outer wall of the expansion portion 220 after the bearing cylinder 300 is fitted over the column 200, thereby achieving the functions of pressing and releasing while facilitating disassembly. It should be noted that by cooperating with the abutment 310 on the bearing cylinder 300 and the expansion portion 220 of the column 200, the abutment 310 only needs to be moved up slightly to loosen the first part 10 inside the expansion portion 220, thereby enabling the quick loading and unloading of the first part 10.

[0088] Please see Figure 5 , Figure 6 Furthermore, in this embodiment, the outer wall of the expanding portion 220 is frustoconical 223, or / and the inner wall of the clamping platform 310 is conical, which cooperates with the outer wall of the expanding portion 220. The specific structure of the expanding portion 220 and the clamping platform 310 can take many forms. For example, in the first form, the outer wall of the expanding portion 220 is frustoconical, and the inner wall of the clamping platform 310 can be arc-shaped or L-shaped, etc. During the downward movement of the bearing cylinder 300, the outer wall of the expanding portion 220 can be gradually squeezed by the downward movement of the clamping platform 310, thereby causing the multiple clamping blocks 221 to move inward and close synchronously. In the second configuration, the inner wall of the clamping platform 310 is conical, and the outer wall of the expanding portion 220 can be arc-shaped or L-shaped, etc. During the downward movement of the bearing cylinder 300, the outer wall of the expanding portion 220 can also be gradually squeezed by the downward movement of the clamping platform 310, thereby causing the multiple clamping blocks 221 to move inward and converge synchronously. Please refer to [link / reference]. Figure 2 , Figure 3 , Figure 5 In this embodiment, a third form is adopted. The outer wall of the expanded portion 220 is frustoconical 223 (trumpet-shaped), and the inner wall of the clamping platform 310 is a conical inner wall 311. The conical inner wall 311 cooperates with the outer wall of the frustoconical 223 of the expanded portion 220. When the clamping platform 310 moves downward along with the bearing cylinder 300, the conical inner wall of the clamping platform 310 moves downward and compresses the outer wall of the expanded portion 220 toward the central axis, thereby causing multiple clamping blocks 221 to move toward the central axis simultaneously. Through the relative movement of the conical surfaces of the two, the radial component force (compression force) is increased, thus clamping the first part 10 in the hole more tightly and fixing it more stably.

[0089] Please see Figure 5 , Figure 6Furthermore, in this embodiment, a clearance groove 222 is formed between adjacent clamping blocks 221, extending from the expansion portion 220 to the column 230. That is, multiple clearance grooves 222 are formed on the side wall of the column 230, with one end extending to the top of the column 200. The multiple clearance grooves 222 facilitate the placement and removal of the first part 10. The presence of the clearance grooves 222 also allows the clamping blocks 221 to be elastic, enabling them to move closer or further apart. By placing the clearance grooves 222 on the column 230, a longer cantilever is created in the portion connecting the clamping blocks 221, resulting in better elasticity. When compressed by the bearing cylinder 300, the clamping block 10 responds more quickly and deforms more sensitively, thus providing a more stable clamping effect.

[0090] Please see Figure 6 , Figure 7 Furthermore, the receiving hole 210 in this embodiment specifically includes: a fixed section 211 located at the bottom, a fastening section 213 enclosed by the expanding portion 220, and an intermediate section 212 located between the fixed section 211 and the fastening section 213; the fixed section 211 is used to position the first part 10, the diameter of the intermediate section 212 is larger than the outer diameter of the first part 10, and the diameter of the fastening section 213 is smaller than the diameter of the intermediate section 212 but larger than the diameter of the fixed section 211. In the specific structure, a section of the fixed section 211 with a diameter equal to the outer diameter of the first part 10 is provided at the bottom of the receiving hole 210, making the gap between them extremely small or almost non-existent, thereby positioning the first part 10 inserted to the bottom. This facilitates the fixation of the first part 10 and prevents the first part 10 from wobbling during the processing of the end face. The fastening section 213 at the top of the receiving hole 210 can retract and quickly clamp the top of the first part 10 when multiple clamping blocks 221 are clamped. During the polishing process, the clamping section 213 and the fixing section 211 can make the clamping of the first part 10 more stable. After the first part 10 is vertically positioned, the end face of the first part 10 is continuously polished by the polishing mold, and the first part 10 will not shake back and forth under the drive of the polishing mold.

[0091] Please see Figure 5 , Figure 8 Furthermore, in this embodiment, the bottom of the column 200 is provided with a locking platform 110. The outer diameter of the locking platform 110 is larger than the outer diameter of the column 230, and the outer wall of the locking platform 110 is provided with an external thread. The lower end of the bearing cylinder 300 is provided with an internal thread, which is connected to the external thread of the locking platform 110. After the internal thread at the bottom of the bearing cylinder 300 is connected to the external thread of the locking platform 110, the bearing cylinder 300 can be moved up and down by turning it. This allows the top of the bearing cylinder 300 to stably squeeze or loosen the flared head.

[0092] Please see Figure 5 , Figure 6 Furthermore, in this embodiment, a base 100 is provided at the end of the locking platform 110 opposite to the column 200. The base 100 is used to connect to the polishing machine. The base 100 has a relatively large diameter, which can stably support and fix the locking platform 110 and the column 200. The bottom of the base 100 can be provided with a threaded hole for mounting on the spindle of the polishing machine. The base 100, the locking platform 110 and the column 200 are concentrically arranged. In this way, when the base 100 is installed on the spindle, it can remain coaxial with the spindle, and the column 200 can also remain coaxial with the spindle, improving the coaxiality during the clamping and fixing process. The base 100 and the column 200 are machined as a single piece. The base 100, the locking table 110 and the column 200 are cut out on the same mounting axis of the machine tool to ensure the coaxiality of the three. Furthermore, the bearing cylinder 300 is cut out on the same mounting axis of the machine tool, which also ensures the coaxiality of the central axis of the bearing cylinder 300 and the central axis of the column 200.

[0093] Please see Figure 4 , Figure 5 , Figure 6 Furthermore, in this embodiment, the top of the support cylinder 300 is provided with a mounting plate 400, and the mounting plate 400 has a through hole 410 connected to the receiving hole 210, so that the first part 10 can be inserted into the receiving hole 210. By providing the mounting plate 400 on the top of the support cylinder 300, and polishing it together with the first part 10 by the polishing mold, the surface of the first part 10 can be guaranteed to be polished on the whole surface during processing, and the surface quality of the end face of the first part 10 is higher.

[0094] Please see Figure 5 , Figure 8 Furthermore, in this embodiment, a stop flange 320 is provided at the top of the support cylinder 300, which forms a mounting groove 321, and a mounting plate 400 is disposed within the mounting groove 321. In a specific structure, the stop flange 320 is positioned above the abutment platform 310, and the mounting groove 321 formed therein is used to arrange the mounting plate 400 around the optical first component 10. The through hole at the center of the mounting plate 400 allows the first component 10 to pass through the through hole.

[0095] Please see Figure 1 , Figure 2 Based on the above-mentioned machining using the first centering clamping fixture, step S200 specifically includes steps S210-S230, as follows:

[0096] Step S210: Fix the first centering clamping fixture to the first processing equipment.

[0097] In the specific structure, the base of the first centering clamping fixture is mounted on the first processing equipment (milling machine).

[0098] Step S220: Insert the first part into the receiving hole of the first centering clamping fixture, and position it by having the bottom surface of the receiving hole abut against the first reference surface, so that the second end of the first part is exposed.

[0099] The fixing section at the bottom of the receiving hole positions the first part inserted into the bottom, which facilitates the fixing of the first part and prevents the first part from swinging when the end face is machined. The bottom surface of the receiving hole abuts against the first reference surface of the first part for limitation, so that the length of the first part extending into the receiving hole is constant, thus improving dimensional accuracy.

[0100] Step S230: By twisting the bearing cylinder sleeved on the column, the bearing cylinder moves along the axial direction of the column. The inner wall of the bearing cylinder is squeezed and expanded. The squeezed and expanded part causes multiple clamping blocks to move synchronously toward the center of the receiving hole.

[0101] Multiple clamping blocks are squeezed by the bearing cylinder and move towards the center of the receiving hole synchronously. This reduces the size of the opening formed by the multiple clamping blocks to clamp the first part located within it. The synchronous movement of the multiple clamping blocks can automatically center the clamped first part, thereby greatly improving the machining accuracy and effectively controlling the center deviation.

[0102] Step S300: The second end of the first part is machined into a spherical surface to obtain the second part, and the center height of the second part is checked to ensure that it meets the predetermined center height standard.

[0103] In the specific process, the second end face of the first part is machined using the first processing equipment (spherical milling machine) to obtain a frosted spherical surface. During the processing stage, the product is positioned using the first centering clamping fixture, and the center deviation can be determined by measuring the edge thickness difference of the spherical end face using a dial indicator, thus controlling the center deviation to meet the predetermined requirements. During the processing, the height dimension is controlled to be within 0.05mm of the finished product dimension, and the center deviation C is controlled to be within 8′.

[0104] The frosted spherical surface is then polished to obtain the finished spherical surface. During the polishing process of the spherical milling machine, the polishing method was optimized and improved by using a circular annular mounting plate, and then using a first centering clamping fixture and 417 glue to polish the end face of the product and the mounting plate as a whole, which increased the polishing area and greatly reduced the difficulty of polishing.

[0105] Therefore, during the machining of the spherical surface at the first end, the first part is installed into the aluminum petal-shaped expansion section, and then a copper support cylinder is used to fix the first part in the column. By improving the accuracy of the automatic centering of the elastic column, the edge thickness difference Δt of the spherical surface of the product is improved by dial indicator measurement. Based on the fact that the center deviation C can be controlled within 8′, the center deviation index of the product is quantitatively calculated and controlled in this way. The possibility of controlling the center deviation during the polishing process is theoretically analyzed, and the theoretical results are verified by direct experiments on the accuracy of the elastic tooling: the edge thickness difference of the product is guaranteed by the accuracy of the first centering clamping tooling, thereby ensuring the key index center deviation.

[0106] Please see Figure 9 After the second part 20 is unloaded, it is placed on the detection and positioning fixture 30, and the center height of the second part 20 is checked to ensure it reaches the predetermined center height standard. The processed second part 20 is then removed from the first centering clamping fixture. To address the problem of inaccurate and unstable inspection indicators in the detection of the center thickness of slender parts, this embodiment designs a detection and positioning fixture 30, which specifically includes: a bottom parallel window 31, a first side square 32, and a second side square 33. The first and second side squares 32 and 33 are both perpendicular to the bottom parallel window 31 and mutually perpendicular. The bottom parallel window 31, the first side square 32, and the second side square 33 form a positioning space. The second part 20 is vertically abutted against the inner wall of the positioning space, and the center height of the second part 20 is determined by detecting its height. The perpendicularity of the inner wall of the positioning space formed by the bottom parallel window piece 31, the first side square piece 32, and the second side square piece 33 is <10″. The inspection positioning fixture 30 is placed on a marble platform, with the outer diameter of the second part 20 abutting against the inner wall of the positioning space. After calibration using a dial indicator based on a standard block to eliminate systematic errors, the center thickness of the product is measured using a dial indicator based on this calibration result, improving inspection accuracy and reliability. In addition to measuring the center thickness with a dial indicator (micrometer), a full-Euro centering instrument is used to check the center deviation to be within 20′; a ZYGO interferometer is used to check the surface shape to be within 0.15λ; and a laser differential confocal measuring instrument is used to check the radius of curvature to be within 0.5fr. Once the center thickness of the second part is qualified, the next step is performed.

[0107] Step S400: Provide a second centering clamping fixture to clamp the outer circle of the second part and machine the first end of the second part into a tapered surface to obtain the finished part.

[0108] Please see Figure 10During the machining of the slender second part 20, to ensure that the center deviation of the conical surface is controllable, based on the theoretical analysis and experimental research on the coaxiality of the plane based on the outer diameter during the machining of the conical angle, a special second centering clamping fixture 40 is designed to quickly clamp the second part 20. The second centering clamping fixture 40 is connected to the milling machine, and the second centering clamping fixture 40 is adjusted by dial indicator to ensure that the outer diameter runout of the second centering clamping fixture 40 is <0.002mm and the coaxiality of the mechanical structure of the second centering clamping fixture 40 is <0.005mm. Based on this method, the error of the milling machine is compensated, thereby improving the accuracy of the coaxiality of the conical angle plane.

[0109] Please see Figure 10 The second centering clamping fixture 40 in this embodiment specifically includes: a fixture base 41, an elastic sleeve 43, and a sleeve nut 45. The fixture base 41 has a tapered positioning hole 42. The tapered positioning hole 42 has high dimensional requirements. The elastic sleeve 43 is installed in the tapered positioning hole 42. The elastic sleeve 43 can be an ER sleeve. By embedding the ER sleeve into the high-precision tapered positioning hole 42, when clamping the second part 20, the outer diameter runout of the processed product can be guaranteed to be <0.01. From the perspective of optical processing, this ensures the coaxiality optical index of the cone angle based on the optical axis. The elastic sleeve 43 has a central shaft hole 44. The sleeve nut 45 is sleeved on the elastic sleeve 43 and screwed onto the fixture base 41. The central shaft hole 44 of the elastic sleeve 43 is used to insert the second part 20. By tightening the sleeve nut 45, the elastic sleeve 43 is compressed and deformed to clamp the second part 20. The second part 20 is fixed by the second centering clamping fixture 40. The spindle is moved on the milling machine, which drives the cone angle processing mold to move, thereby milling the cone angle on the side of the first end of the second part 20, thus processing a cone surface at the first end. The diameter of the cone surface is Φ1±0.5mm (top); the angle of the cone angle is 20°±30′; and the coaxiality of the cone angle surface with respect to the optical axis is <0.02mm.

[0110] Please see Figure 2 , Figure 3 Step S400 specifically includes steps S410-S440, as follows:

[0111] Step S410: Fix the tooling base to the second processing equipment, and use a dial indicator to adjust the eccentricity between the second centering clamping tool and the spindle of the second processing equipment to achieve the predetermined coaxiality requirement.

[0112] This ensures that the rotation center of the milling machine's spindle is coaxial with the central axis of the tooling base of the second centering clamping fixture. This guarantees that the center deviation is controllable during machining, meeting the accuracy requirements for center deviation.

[0113] Step S420: Insert the second part into the central hole of the elastic sleeve, and make the spherical surface of the second part abut against the limiting hole for limiting, so that the first end of the second part is exposed.

[0114] Step S430: By tightening the nut on the tooling base, the elastic sleeve clamps the outer circle of the second part.

[0115] First, install the collet nut and the elastic collet, ensuring the side groove of the elastic collet is positioned at the eccentric circle of the collet nut. Connect the collet nut to the fixture base. Following the arrow direction, push the elastic collet into the tapered positioning hole of the fixture base until a click is heard, indicating the collet is properly installed. Next, insert the second part into the center hole of the spring collet. Once fully inserted, tighten the collet nut. The collet nut's compression of the spring collet (ER collet) causes it to center and contract, simultaneously clamping and centering the second part within the central shaft hole. By embedding the ER collet into the high-precision tapered positioning hole, the outer diameter runout of the machined product can be guaranteed to be <0.01 mm when clamping the second part.

[0116] Step S440: The first end of the second part is milled into a conical surface using the second processing equipment.

[0117] The second part is fixed by a second centering clamping fixture. The conical machining mold is moved by moving the spindle on the milling machine. The machining surface of the conical machining mold is offset from the central axis of the second centering clamping fixture by a certain angle. When the spindle rotates, it drives the conical machining mold to rotate, so that the first end of the second part can be machined into a conical surface. During the machining process, the top diameter of the conical surface needs to be detected and controlled to meet the dimensional requirements. This ensures the dimensional requirements of the conical surface and obtains the finished part.

[0118] After machining is complete, unscrew the collet nut from the second machined part and pull out the finished part. If necessary, remove the spring collet from the collet nut by pushing it inward from the front of the spring collet while pressing down on the bottom of the eccentric circle. Push the spring collet at an angle until the spring collet and collet nut separate.

[0119] Steps S410-S440 above are based on theoretical analysis and experimental research on the coaxiality of the plane based on the outer diameter during the cone angle machining process. By designing a special ER sleeve, the product can be quickly clamped. The elastic sleeve is used to compensate for the error of the machining equipment, thereby improving the accuracy of the coaxiality of the cone angle plane.

[0120] Step S500: Check that the center height of the finished part meets the predetermined center height standard.

[0121] Please see Figure 11In the specific process, the detection and positioning fixture 30 designed in the above steps can still be used for dimensional detection. The outer diameter of the finished part 1 is placed against the inner wall of the detection and positioning fixture 30, and the center height of the finished part 1 is measured using a calibration table after alignment with a standard block. The center thickness of the product is measured using a dial indicator. This improves the detection accuracy and reliability. During the detection process, the following parameters also need to be measured: the diameter of the detection plane end (top surface of the cone), the cone angle, and the coaxiality of the finished part 1. Through the above processing method, the center deviation Cop of the spherical end face relative to the outer diameter can be <8′. The coaxiality of the cone surface relative to the optical axis is <0.02mm. The diameter of the top surface of the cone is Φ1±0.5mm. All surface shape detection mentioned in this embodiment is performed using a 633nm laser.

[0122] In summary, this application provides an optical cold processing method for slender cylindrical lenses. Through the cooperation of a first centering clamping fixture and a Maijun polishing machine, the spherical surface processing quality is ensured and the processing efficiency is improved. A second centering clamping fixture is designed to achieve high-precision processing of the cone angle. Furthermore, a high-precision detection and positioning fixture is built during the processing to detect key indicators. The first centering clamping fixture effectively controls the center deviation Creverse to meet quality requirements by controlling the edge thickness difference. During the processing stage, the product is positioned using the first centering clamping fixture, and the center deviation can be determined by measuring the edge thickness difference of the spherical end face using a dial indicator, thus controlling the center deviation to meet predetermined requirements. The use of the first centering clamping fixture ensures that the center deviation Creverse of the slender lens product is within 8′. Furthermore, by ensuring the processing of optical indicators based on the first centering clamping fixture and employing the Maijun high-efficiency polishing machine, the processing difficulty is greatly reduced and the processing efficiency is improved. When implementing this solution, the operator's fine operational restrictions are not as high as those of manual or mechanical tooling control. The operability is greatly improved by using the first centering clamping tool and compensation method.

[0123] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for optical cold processing of a slender cylindrical lens, characterized in that, Including the following steps: An optical blank with a predetermined outer diameter is provided, and the first end of the optical blank is machined into a first reference surface to obtain a first part; A first centering clamping fixture is provided, which clamps the outer circle of the first part using the first reference surface as the positioning reference. The first centering clamping fixture includes a column and a bearing cylinder. The column is provided with a receiving hole, and the bearing cylinder is sleeved on the column. The end of the column facing the opening of the receiving hole is provided with an expansion portion. The expansion portion includes a plurality of clamping blocks arranged at intervals around the central axis of the receiving hole. The first centering clamping fixture is fixed on a first processing equipment. The first part is inserted into the receiving hole of the first centering clamping fixture and positioned by the bottom surface of the receiving hole against the first reference surface, so that the second end of the first part is exposed. By twisting the bearing cylinder sleeved on the column, the bearing cylinder moves along the axial direction of the column. The inner wall of the bearing cylinder squeezes the expansion portion. The squeezed expansion portion causes the plurality of clamping blocks to move synchronously toward the center of the receiving hole, so as to automatically center the first part during the clamping process. The second end of the first part is machined into a spherical surface to obtain the second part, and the center height of the second part is checked to ensure that it meets the predetermined center height standard; A second centering clamping fixture is provided to clamp the outer circle of the second part. The fixture base of the second centering clamping fixture is fixed on the second processing equipment. The eccentricity between the second centering clamping fixture and the spindle of the second processing equipment is adjusted by dialing to achieve the predetermined coaxiality requirement. The first end of the second part is processed into a tapered surface to obtain the finished part. The center height of the finished part is checked to ensure it meets the predetermined center height standard.

2. The optical cold processing method for slender cylindrical lenses as described in claim 1, characterized in that, The steps of providing an optical blank with a predetermined outer diameter and machining the first end of the optical blank into a first reference surface to obtain a first part include: The optical blank is fixed on the optical adhesive plate, and the end face of the first end of the optical blank is ground to the predetermined size. The end face after grinding is polished to form the first reference surface.

3. The optical cold processing method for slender cylindrical lenses as described in claim 2, characterized in that, After the step of polishing the ground end face to form the first reference surface, the following steps are also included: Using the first reference surface as the positioning reference, the outer circle of the second end of the first part is polished to achieve the predetermined polishing quality.

4. The optical cold processing method for slender cylindrical lenses as described in claim 1, characterized in that, In the step of machining the second end of the first part into a spherical surface to obtain the second part, and detecting that the center height of the second part reaches the predetermined center height standard: The second end face of the first part is processed by the first processing equipment to obtain a frosted spherical surface; The frosted spherical surface is polished to obtain the finished spherical surface.

5. The optical cold processing method for slender cylindrical lenses as described in claim 1, characterized in that, The step of machining the second end of the first part into a spherical surface to obtain the second part, and detecting that the center height of the second part reaches the predetermined center height standard, further includes: After the second part is placed on the inspection and positioning fixture, the center height of the second part is checked to ensure that it reaches the predetermined center height standard. The detection and positioning fixture includes: a bottom parallel window, a first side square piece, and a second side square piece. The first side square piece and the second side square piece are both perpendicular to the bottom parallel window and are perpendicular to each other. The bottom parallel window, the first side square piece, and the second side square piece form a positioning space. The second part is vertically abutted against the inner wall of the positioning space, and the center height of the second part is determined by detecting the height of the second part.

6. The optical cold processing method for a slender cylindrical lens as described in claim 1, characterized in that... , The second centering clamping fixture includes: a fixture base, an elastic sleeve, and a sleeve nut. The fixture base has a tapered positioning hole. The elastic sleeve is used to be installed in the tapered positioning hole. The elastic sleeve has a central shaft hole. The sleeve nut is sleeved on the elastic sleeve and screwed onto the fixture base. The central hole of the elastic sleeve is used to insert the second part. By tightening the sleeve nut, the elastic sleeve is compressed and deformed to clamp the second part. The steps include: providing a second centering clamping fixture to hold the outer circle of the second part; fixing the fixture base of the second centering clamping fixture to a second machining equipment; adjusting the eccentricity between the second centering clamping fixture and the spindle of the second machining equipment using a dial indicator to achieve a predetermined coaxiality requirement; and machining the first end of the second part into a tapered surface to obtain the finished part. Fix the tooling base to the second processing equipment, and use a dial indicator to adjust the eccentricity between the second centering clamping tool and the spindle of the second processing equipment to achieve the predetermined coaxiality requirement; Insert the second part into the central shaft hole of the elastic sleeve, so that the first end of the second part is exposed; By tightening the nut on the tooling base, the elastic sleeve clamps the outer circle of the second part. The second processing equipment is used to mill and grind the first end of the second part into a tapered surface.

7. The optical cold processing method for slender cylindrical lenses as described in claim 1, characterized in that, In the step of detecting whether the center height of the finished part reaches the predetermined center height standard: The outer diameter of the finished part is pressed against the inner wall of the detection and positioning fixture; The center height of the finished part is measured using a test table after calibration with a standard block.

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