A method for machining and testing large-diameter-to-thickness optical elements and for their calibration

Abstract

This invention discloses a processing and testing fixture and calibration method for large-aspect-to-thickness optical components. The fixture includes: a first clamping member and a first washer. The first clamping member has a first clamping surface corresponding to a first end face, and the first washer is disposed on the first clamping surface; a second clamping member and a second washer. The second clamping member has a second clamping surface corresponding to a second end face, and the second washer is disposed on the second clamping surface; wherein the first clamping member and the second clamping member are detachably connected. This invention's processing and testing fixture for large-aspect-to-thickness optical components, by providing flexible first and second washers on the first clamping surface of the first clamping member and the second clamping surface of the second clamping member respectively, buffers and homogenizes the clamping force, thereby effectively solving the technical problems of localized stress concentration, subsurface damage, and even breakage of components caused by rigid clamping in the prior art.

Description

Technical Field

[0001] This invention relates to the field of optical element inspection and processing technology, and in particular to a tooling and calibration method for processing and inspecting large-diameter-to-thickness optical elements. Background Technology

[0002] In the precision machining and testing of optical components, specialized tooling fixtures are typically required to clamp and position the optical components. Existing specialized tooling fixtures usually employ two interlocking rigid clamping blocks, which are directly pressed onto the upper and lower surfaces of the optical component or specific clamping points by fasteners such as bolts. Clamping force and positioning are provided by the hard contact between the metal and the surface of the optical component.

[0003] However, for optical components with a large aspect ratio and weak rigidity, the rigid clamp is prone to local stress concentration in the contact area when force is applied, which can cause subsurface damage, microcracks or even breakage of the optical component. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a tooling and calibration method for processing and inspecting optical elements with a large diameter-to-thickness ratio. This solves the technical problem that existing tooling fixtures are prone to local stress concentration in the contact area when applying force to optical elements with a large diameter-to-thickness ratio and weak rigidity, which leads to subsurface damage, microcracks or even breakage of the optical elements.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a large-diameter-to-thickness optical element processing and inspection fixture for clamping optical elements. The optical element includes a body portion and a clamping portion. The clamping portion is connected to the outer peripheral side of the body portion. The clamping portion has a first end face and a second end face disposed opposite to each other, and a first outer peripheral side face connected between the first end face and the second end face. The large-diameter-to-thickness optical element processing and inspection fixture includes: a first clamping member and a first washer. The first clamping member is provided with a first clamping surface corresponding to the first end face, and the first washer is disposed on the first clamping surface. A second clamping member and a second washer are provided. The second clamping member is provided with a second clamping surface corresponding to the second end face, and the second washer is disposed on the second clamping surface. The first clamping member and the second clamping member are detachably connected, and a clamping space for accommodating the clamping portion is formed between the first clamping surface and the second clamping surface.

[0006] In some embodiments, the large diameter-to-thickness ratio optical element processing and inspection fixture is further provided with a third washer; the first clamping member is further provided with a first inner peripheral side corresponding to the first outer peripheral side, and the third washer is provided on the first inner peripheral side.

[0007] In some embodiments, the second clamping member is further provided with a second inner peripheral side corresponding to the first outer peripheral side, the first inner peripheral side and the second inner peripheral side are spliced ​​together, and the third washer is disposed on the first inner peripheral side and the second inner peripheral side.

[0008] In some embodiments, the first clamping surface is provided with a first mounting groove, and a portion of the first washer is embedded in the first mounting groove; And / or, the second clamping surface is provided with a second mounting groove, and a portion of the second washer is embedded in the second mounting groove.

[0009] In some embodiments, the body portion has a second outer peripheral side surface adjacent to the first end face, and an optical curved surface adjacent to the second outer peripheral side surface; The first clamping member is further provided with a third inner peripheral side corresponding to the second outer peripheral side, and a transition surface adjacent to the third inner peripheral side, the transition surface having the same curvature as the optical surface.

[0010] In some embodiments, the second clamping member is provided with a hanging hole for connecting to a hook of a testing bracket.

[0011] In some embodiments, the large diameter-to-thickness optical element processing and testing fixture further includes a first lifting ring, which is connected to the second clamping member, and the central axis of the lifting hole formed by the first lifting ring is perpendicular to the second clamping surface.

[0012] In some embodiments, the large diameter-to-thickness ratio optical element processing and testing fixture further includes a second lifting ring, which is connected to the second clamping member, and the central axis of the lifting hole formed by the second lifting ring is parallel to the second clamping surface.

[0013] Secondly, the present invention provides a method for verifying the use of the large-diameter-to-thickness ratio optical element processing and inspection fixture described in the first aspect, the method comprising a security strength verification, the security strength verification including: Finite element mechanical simulation was performed on the assembly formed by clamping the optical element with the large diameter-to-thickness ratio optical element processing and testing fixture under the hoisting condition. The hoisting condition includes at least a horizontal hoisting state and a vertical hoisting state. The maximum working stress in the optical element is determined based on the simulation results of the finite element mechanical simulation. The safety factor of the optical element is determined based on the maximum working stress and the material strength limit of the optical element. If the safety factor is greater than the first preset value, then the large diameter-to-thickness ratio optical element processing and testing fixture is determined to meet the safety and strength requirements under the corresponding hoisting conditions.

[0014] In some embodiments, the verification method further includes detection accuracy verification, which includes: Finite element mechanical simulation was performed on the assembly formed after the large diameter-to-thickness optical element was clamped by the processing and testing fixture to obtain the stress and deformation data of the optical element. The optical additional wavefront distribution generated by the tooling clamping of the optical element is determined based on the stress deformation data. If the root mean square value of the optical additional wavefront distribution is less than the second preset value, then the large diameter-to-thickness optical element processing and testing fixture is determined to meet the testing accuracy requirements.

[0015] The large diameter-to-thickness ratio optical element processing and testing fixture of the present invention, by providing flexible first and second washers on the first clamping surface of the first clamping member and the second clamping surface of the second clamping member respectively, allows the clamping force to be buffered and homogenized, thereby effectively solving the technical problems of local stress concentration, subsurface damage and even breakage of the element caused by rigid clamping in the prior art.

[0016] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are described in detail below. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of the processing and testing fixture for large diameter-to-thickness optical elements according to an embodiment of the present invention; Figure 2 This is a top view schematic diagram of the processing and testing fixture for large diameter-to-thickness optical elements according to an embodiment of the present invention; Figure 3 This is a first cross-sectional view of the large diameter-to-thickness optical element processing and inspection fixture according to an embodiment of the present invention; Figure 4 This is a second cross-sectional view of the large diameter-to-thickness ratio optical element processing and inspection fixture according to an embodiment of the present invention; Figure 5 for Figure 4 A magnified structural diagram of part A; Figure 6 This is a cross-sectional view of the first clamping component of the large diameter-to-thickness ratio optical element processing and inspection fixture according to an embodiment of the present invention; Figure 7 for Figure 6 A schematic diagram of the enlarged structure of part B; Figure 8 This is a cross-sectional view of the second clamping component of the large diameter-to-thickness ratio optical element processing and inspection fixture according to an embodiment of the present invention; Figure 9 for Figure 8 A magnified structural diagram of part C; Figure 10 This is a schematic diagram of the structure of the large diameter-to-thickness optical element processing and inspection fixture in the optical element processing scenario according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the structure of the large diameter-to-thickness optical element processing and testing fixture in the scenario of optical element testing according to an embodiment of the present invention; Figure 12 Finite element mechanical simulation of the optical element in a horizontally suspended state using a large diameter-to-thickness optical element processing and testing fixture according to an embodiment of the present invention; Figure 13 Finite element mechanical simulation of the optical element in the vertical hoisting state using the large diameter-to-thickness optical element processing and testing fixture of this invention; Figure 14 This is a diagram showing the additional optical wavefront distribution of an optical element when it is held in a large diameter-to-thickness ratio optical element processing and testing fixture according to an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. Optical element; 11. Body part; 12. Clamping part; 2. First clamping member; 21. First washer; 22. First mounting groove; 23. First clamping surface; 24. First inner peripheral side surface; 25. Third inner peripheral side surface; 26. Transition surface; 3. Second clamping member; 31. Second washer; 32. Second mounting groove; 33. Second clamping surface; 34. Second inner peripheral side surface; 35. Hanging hole; 4. First lifting ring; 5. Second lifting ring; 6. Third washer; 7. Worktable; 71. Stop; 8. Detection bracket. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] Furthermore, 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 indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0026] In the precision machining and testing of optical components, specialized tooling fixtures are typically required to clamp and position the optical components. Existing specialized tooling fixtures usually employ two interlocking rigid clamping blocks, which are directly pressed onto the upper and lower surfaces of the optical component or specific clamping points by fasteners such as bolts. Clamping force and positioning are provided by the hard contact between the metal and the surface of the optical component.

[0027] However, for optical components with a large aspect ratio and weak rigidity, the rigid clamp is prone to local stress concentration in the contact area when force is applied, which can cause subsurface damage, microcracks or even breakage of the optical component.

[0028] Please see Figures 1-9 This invention provides a large-diameter-to-thickness optical element processing and testing fixture for clamping an optical element 1. The optical element 1 includes a body portion 11 and a clamping portion 12. The clamping portion 12 is connected to the outer peripheral side of the body portion 11 and has a first end face and a second end face disposed opposite to each other, as well as a first outer peripheral side face connected between the first end face and the second end face. The large-diameter-to-thickness optical element processing and testing fixture includes: a first clamping member 2 and a first washer 21. The first clamping member 2 is provided with a first clamping surface 23 corresponding to the first end face, and the first washer 21 is disposed on the first clamping surface 23; a second clamping member 3 and a second washer 31. The second clamping member 3 is provided with a second clamping surface 33 corresponding to the second end face, and the second washer 31 is disposed on the second clamping surface 33. The first clamping member 2 and the second clamping member 3 are detachably connected, and a clamping space for accommodating the clamping portion 12 is formed between the first clamping surface 23 and the second clamping surface 33.

[0029] For example, in this embodiment, optical element 1 refers to an optical mirror or lens with a large diameter-to-thickness ratio, thus exhibiting weak structural rigidity, such as a large-aperture aspherical mirror. Its characteristic is that its thickness is much smaller than its aperture, making it highly susceptible to deformation or damage from external forces during clamping and bearing. For example, the body portion 11 is the main optical functional part of optical element 1, typically the central region containing a precision optical surface, and is the core part for light propagation, reflection, or refraction, thus realizing optical functions. For example, the clamping portion 12 is the bearing structure part of optical element 1 specifically designed for mechanical clamping, typically an annular edge or boss structure machined around the outer periphery of the body portion 11. Its first end face, second end face, and first outer peripheral side face together constitute the area where the tooling applies force, thereby isolating the clamping force from the body portion 11, which is the optical functional area, and preventing the clamping operation from directly affecting the surface accuracy of the optical surface.

[0030] For example, the first clamping surface 23 and the second clamping surface 33 are respectively formed on the first clamping member 2 and the second clamping member 3, serving as bearing surfaces for contacting the first end face and the second end face. For example, the first clamping surface 23 and the second clamping surface 33 are parallel or conformally corresponding to each other in an ideal assembly state to ensure that a uniform and vertical pressure can be applied to the two end faces of the clamping part 12 during clamping, avoiding overturning moment caused by uneven force, thereby preventing unnecessary bending deformation of the body part 11 of the optical element 1.

[0031] For example, the first washer 21 and the second washer 31 are made of rubber and are ring-shaped, used to provide an elastic and flexible contact interface between the first / second clamping surface 33 and the first / second end face of the clamping part 12. When the first clamping member 2 and the second clamping member 3 are connected and tightened by fasteners such as bolts, the rubber washer will undergo controllable elastic deformation. On the one hand, it can compensate for the small dimensional errors in the machining and assembly of the parts and ensure sufficient contact; on the other hand, it can transform the concentrated mechanical clamping force into a more uniformly distributed pressure, thereby greatly alleviating or even eliminating local stress concentration and protecting the fragile optical element 1 from subsurface damage or breakage.

[0032] It is understood that by providing flexible first washers 21 and second washers 31 on the first clamping surface 23 of the first clamping member 2 and the second clamping surface 33 of the second clamping member 3 respectively, the clamping force can be buffered and homogenized, thereby effectively solving the technical problems of local stress concentration, subsurface damage and even breakage of components caused by rigid clamping in the background art.

[0033] In some embodiments, the large diameter-to-thickness ratio optical element processing and inspection fixture is further provided with a third washer 6; the first clamping member 2 is further provided with a first inner peripheral side 24 corresponding to the first outer peripheral side, and the third washer 6 is provided on the first inner peripheral side 24.

[0034] For example, when the optical element 1 is placed horizontally and mainly supported by the first clamping member 2, the clamping part 12 can be completely embedded in the cavity formed by the first inner peripheral side 24 and the first clamping surface 23 of the first clamping member 2. At this time, the first outer peripheral side of the optical element 1 and the first inner peripheral side 24 of the first clamping member 2 are approximately overlapped in the radial direction or maintain a small, uniform gap. Furthermore, the third washer 6 is disposed between the first inner peripheral side 24 and the first outer peripheral side. When the element has a slight tendency to displace in the radial direction due to its own weight or a slight external force, the third washer 6 will undergo elastic deformation, providing cushioning and always maintaining contact with both sides, thereby eliminating possible hard collisions, friction, or scratches between the first outer peripheral side of the optical element 1 and the first inner peripheral side 24 of the first clamping member 2.

[0035] For example, the third washer 6 is made of polytetrafluoroethylene (PTFE). When the first outer peripheral side and the first inner peripheral side 24 are in relative motion or under force contact, the PTFE washer can minimize the sliding friction resistance and effectively prevent the fragile side of the optical element 1 from being scratched. At the same time, its certain flexibility can also compensate for the assembly gap and prevent the optical element 1 from shaking.

[0036] It is understood that this embodiment extends the concept of flexible contact and buffer protection from the axial end face of the optical element 1 to the radial side by adding a third washer 6 to the inner circumferential side of the first clamping member 2. The first washer 21 and the second washer 31 of the first clamping surface 23 and the second clamping surface 33 absorb and homogenize the axial clamping force to prevent crushing. The third washer 6 on the first inner circumferential side 24 is responsible for dealing with radial contact, friction and possible minor impacts, so that the entire clamping contact interface of the optical element 1 is "softly isolated" from the first clamping member 2 and the second clamping member 3. This fundamentally eliminates the risk of stress concentration, surface scratches or breakage caused by hard contact in any direction, and significantly improves the safety and reliability of use under complex working conditions.

[0037] In some embodiments, the second clamping member 3 is further provided with a second inner peripheral side 34 corresponding to the first outer peripheral side, the first inner peripheral side 24 and the second inner peripheral side 34 are spliced ​​together, and the third washer 6 is disposed on the first inner peripheral side 24 and the second inner peripheral side 34.

[0038] For example, after the first clamping member 2 and the second clamping member 3 are connected by fasteners such as bolts, the clamping part 12 of the optical element 1 is housed together in the complete cavity formed by the first clamping member 2 and the second clamping member 3. Specifically, the clamping part 12 can be partially embedded in the cavity formed by the first inner peripheral side 24 and the first clamping surface 23 of the first clamping member 2, and the other part can be embedded in the cavity formed by the second inner peripheral side 34 and the second clamping surface 33 of the second clamping member 3. At this time, the first inner peripheral side 24 of the first clamping member 2 and the second inner peripheral side 34 of the second clamping member 3 are tightly spliced ​​at the joint, together forming a continuous constraint inner wall that surrounds the entire first outer peripheral side of the optical element 1.

[0039] For example, the third washer 6 is configured as a continuous annular body, or is formed by two washer segments respectively attached to the first inner circumferential side 24 and the second inner circumferential side 34 and tightly joined together at the joint. When the first and second clamping members 3 are closed and locked, the third washer 6 is subjected to radial compression from the side of the optical element 1 and the inner wall of the clamping members, resulting in uniform elastic deformation, thereby providing flexible radial support and constraint for the optical element 1 in the entire circumferential direction.

[0040] like Figures 6-9 As shown, in some embodiments, the first clamping surface 23 is provided with a first mounting groove 22, and a portion of the first washer 21 is embedded in the first mounting groove 22; and / or, the second clamping surface 33 is provided with a second mounting groove 32, and a portion of the second washer 31 is embedded in the second mounting groove 32.

[0041] For example, the first mounting groove 22 is an annular groove with a rectangular or semi-circular cross-section machined on the first clamping surface 23, which allows a portion of the cross-section of the first washer 21 to be embedded and accommodated within the first mounting groove 22 in its free state. Similarly, the second mounting groove 32 is an annular groove machined on the second clamping surface 33 in the same or mirror-symmetrical manner, for accommodating the second washer 31 in the same manner.

[0042] It is understood that this embodiment provides a rigid and precise spatial positioning reference for the soft first washer 21 and second washer 31 by setting a first mounting groove 22 on the first clamping surface 23, setting a second mounting groove 32 on the second clamping surface 33, embedding the first washer 21 in the first mounting groove 22, and embedding the second washer 31 in the second mounting groove 32. This ensures that the first washer 21 and the second washer 31 will not slide laterally or twist due to force during assembly and clamping, thereby ensuring the accuracy and repeatability of the pressure application position.

[0043] like Figures 6-7As shown, in some embodiments, the body portion 11 has a second outer peripheral side surface adjacent to the first end face, and an optical curved surface adjacent to the second outer peripheral side surface; the first clamping member 2 is also provided with a third inner peripheral side surface 25 corresponding to the second outer peripheral side surface, and a transition surface 26 adjacent to the third inner peripheral side surface 25, the transition surface 26 having the same curvature as the optical curved surface.

[0044] For example, the second outer peripheral side surface of the body portion 11 is a cylindrical or conical transition area connecting the first end face of the clamping portion 12 and the optical surface, which is a precision surface shape on the body portion 11 that realizes its core optical function. The transition surface 26 of the first clamping member 2 is a convex curved surface formed between its third inner peripheral side surface 25 and the first clamping surface 23.

[0045] It is understandable that the transition surface 26 has the same curvature as the optical surface, meaning that under ideal assembly conditions, the geometric profile of the transition surface 26 is a natural and smooth extension of the optical surface in the clamping area. Therefore, when the optical element 1 is installed in the clamping fixture, the transition surface 26 of the first clamping member 2 and the optical surface of the optical element 1 body 11 achieve geometric conformity and seamless connection at the boundary, avoiding sharp geometric discontinuities or steps at the clamping boundary. This ensures that the clamping force and constraint transmitted from the clamping part 12 are uniformly transmitted to the optical element 1 through a smooth geometric transition, effectively preventing stress concentration or unwanted bending moments in the edge area of ​​the optical surface, thereby maximizing the protection of the surface accuracy of the body 11 from the impact of the clamping process.

[0046] In some embodiments, the second clamping member 3 is provided with a hanging hole 35, which is used to connect with the hook of the detection bracket 8.

[0047] For example, the second clamping member 3 is an octagonal frame structure, and the center of the octagonal frame is a large area of ​​hollowing out, which greatly reduces the overall weight of the tooling and avoids the optical path being blocked during optical inspection; in addition, the multiple straight sides of the octagonal frame also provide a convenient mounting surface for integrating various functional interfaces.

[0048] For example, the hanging hole 35 is a through hole machined on one or more sides of the octagonal frame. The hanging hole 35 and the cylindrical hook of the inspection bracket 8 form a precise clearance fit or transition fit. During inspection, by inserting the hook of the inspection bracket 8 into the hanging hole 35, a fast, accurate, and reliable mechanical connection and positioning between the entire clamping fixture and the inspection bracket 8 can be achieved, establishing a stable installation reference for subsequent precision optical surface inspection.

[0049] like Figure 1As shown, in some embodiments, the large diameter-to-thickness ratio optical element processing and testing fixture further includes a first lifting ring 4, which is connected to a second clamping member 3, and the central axis of the lifting hole formed by the first lifting ring 4 is perpendicular to the second clamping surface 33.

[0050] For example, the first lifting ring 4 is detachably connected to a pre-set, strength-checked mounting point on the second clamping member 3 via a threaded rod at its bottom or a bolt passing through its body. For example, the first lifting ring 4 can be indirectly connected to the second clamping member 3 via a detachable vertical lifting reinforcement block, which is bolted to the second clamping member 3, and the first lifting ring 4 is connected to this reinforcement block. For example, the central axis of the lifting hole formed by the first lifting ring 4 is designed to be perpendicular to the second clamping surface 33 of the second clamping member 3, ensuring that when the hook of the lifting equipment passes through the first lifting ring 4 and is lifted vertically, the entire fixture, along with its internal optical element 1, will be lifted and moved in a horizontal position.

[0051] Understandably, the first lifting ring 4 provides a dedicated, high-strength lifting point, directly and reliably transferring the lifting force to the second clamping member 3, which serves as the main load-bearing structure. This avoids slippage, instability, and accidental damage to tooling and components that may occur during transport due to temporary binding or the use of general-purpose lifting tools. Furthermore, the perpendicular relationship between the lifting hole axis of the first lifting ring 4 and the second clamping surface 33 defines that the optical element 1 remains horizontal during lifting. This is crucial for the large diameter-to-thickness ratio, weakly rigid optical element 1, because a horizontal posture allows its gravity to be evenly distributed across the entire clamping surface, resulting in the most ideal stress state and effectively avoiding additional bending stress caused by uneven gravity distribution under inclined or vertical postures.

[0052] In some embodiments, the large diameter-to-thickness ratio optical element processing and inspection fixture further includes a second lifting ring 5, which is connected to the second clamping member 3, and the central axis of the lifting hole formed by the second lifting ring 5 is parallel to the second clamping surface 33.

[0053] For example, the lifting hole formed by the second lifting ring 5 is designed with its central axis parallel to the second clamping surface 33 of the second clamping member 3. When the hook of the lifting equipment passes through this lifting hole and lifts vertically upward, since the tension of the sling is in the same direction as the axis of the lifting hole, the tension will drive the entire fixture together with the optical element 1 inside it to rotate around the horizontal axis until the fixture reaches a state of force balance, and finally make the second clamping surface 33 become vertical, so that the optical element 1 presents and stabilizes in a vertical position.

[0054] like Figure 10 As shown, Figure 10This is a schematic diagram of the structure of the large diameter-to-thickness optical element processing and testing fixture in the optical element processing scenario according to an embodiment of the present invention. It includes a worktable 7, a stop block 71, and the aforementioned large diameter-to-thickness optical element processing and testing fixture. Multiple stops block 71s are provided, and multiple stops block 71s form an accommodating space. The large diameter-to-thickness optical element processing and testing fixture is positioned in the accommodating space. The multiple stops block 71s are movably connected to the worktable 7, and moving the stops block 71s can change the area and shape of the accommodating space.

[0055] For example, the worktable 7 is a component of the machine tool and can be a metal platform with high rigidity and high flatness. Its surface is usually machined with standard T-slots or mesh threaded holes for mounting and fixing various fixtures, stops 71 and other process equipment, providing a stable reference for the entire machining system.

[0056] For example, multiple stops 71 are rigid positioning blocks that can be moved and locked independently. Each stop 71 has a T-bolt or slider at its bottom that matches the T-slot of the worktable 7, allowing it to slide along the direction of the slot. For example, by loosening the T-bolt, the position of each stop 71 on the worktable 7 can be adjusted individually; after adjustment, it is re-locked, and the stop 71 is firmly fixed. By coordinating the movement of multiple stops 71, the length, width, and even shape of the accommodating space they enclose can be changed, so that its inner dimensions are precisely matched with the outer contour of the large-diameter-to-thickness optical element processing and inspection fixture to be positioned, achieving rapid, adaptive, and gapless positioning and clamping of the fixture.

[0057] like Figure 11 As shown, Figure 11 This is a schematic diagram of the structure of the large diameter-to-thickness optical element processing and testing fixture in the scenario of optical element testing according to an embodiment of the present invention. It includes a testing bracket 8, a hook, and the aforementioned large diameter-to-thickness optical element processing and testing fixture. The hook is connected to the testing bracket 8, and the large diameter-to-thickness optical element processing and testing fixture is connected to the hook.

[0058] For example, the inspection bracket 8 is a multi-dimensional adjustment support device for precision optical inspection, used to accurately support and adjust the spatial orientation of the fixture on which the optical element 1 is mounted. Specifically, the inspection bracket 8 typically has at least two-dimensional (e.g., yaw and pitch) angle adjustment capabilities, with an adjustment range of ±3° and an adjustment resolution at the arcsecond level. For example, the bottom of the inspection bracket 8 is fixed to a stable foundation or vibration isolation platform, while the upper end is provided with an interface for connecting hooks. It is understood that through the inspection bracket 8, the operator can fine-tune the angle of the clamping fixture positioned on the inspection bracket 8 and the optical element 1 clamped therein, ensuring that the normal of its reflecting surface is precisely aligned with the inspection optical path, which is a prerequisite for achieving high-precision surface shape measurement.

[0059] For example, the hook is a connector that links the inspection bracket 8 to the large-diameter-to-thickness optical element processing and inspection fixture. One end of the hook is fixed to the end of the extended arm of the inspection bracket 8 by a thread or quick-release mechanism, while the other end is machined with an outer cylindrical surface. This outer cylindrical surface forms a clearance fit or transition fit with the pre-set hanging hole 35 on the second clamping member 3 of the large-diameter-to-thickness optical element processing and inspection fixture. In use, the operator or auxiliary equipment moves the clamping fixture horizontally, so that the other end of the hook is inserted into the hanging hole 35 of the fixture, thereby completing the mechanical connection.

[0060] Please see Figure 12 and Figure 13 This invention provides a method for verifying a fixture used in the processing and testing of large-diameter-to-thickness optical components. The verification method includes a safety and strength verification, which comprises steps S100-S400: S100. The assembly formed by the processing and testing fixture for large diameter-to-thickness optical elements is subjected to finite element mechanical simulation under the hoisting condition. The hoisting condition includes at least horizontal hoisting and vertical hoisting.

[0061] For example, finite element mechanical simulation first requires establishing a three-dimensional assembly model that includes the machining and testing fixture for the large-diameter-to-thickness optical element and the optical element itself. Each component needs to be assigned realistic material properties, such as elastic modulus, Poisson's ratio, density, and ultimate tensile strength. The contact relationships between the components need to be defined, such as the contact between the clamping part and the washer, and between the washer and the optical element clamping part, in order to simulate real force transmission.

[0062] For example, in the simulation of a horizontal hoisting configuration, the degrees of freedom of the tooling lifting points are constrained, and an inertial load equal to the total weight and aligned with the direction of gravity is applied to the entire assembly to simulate its static state of being horizontally hoisted and supported only by the lifting points. For example, in the simulation of a vertical hoisting configuration, the assembly is vertically hoisted with the load borne by the substructure.

[0063] S200. The maximum working stress in the optical element is determined based on the simulation results of finite element mechanical simulation.

[0064] For example, after the finite element software completes the solution, it can output the stress tensors of each node in the model. Through post-processing, a stress contour map of the entire optical element can be drawn. For example, the region with the highest stress can be visually identified from the stress contour map, and the maximum equivalent stress value of that region, i.e., the maximum working stress, can be directly read using software tools.

[0065] S300. The safety factor of the optical element is determined based on the maximum working stress and the material strength limit of the optical element.

[0066] For example, the ultimate tensile strength of an optical element is a known intrinsic property of the material, provided by the material supplier or obtained through standard testing. For example, the safety factor is the ultimate tensile strength divided by the maximum working stress. For example, if the ultimate tensile strength of a certain optical glass is 100 MPa, and simulation calculations show that its maximum working stress under a certain hoisting condition is 6.67 MPa, then the safety factor is 100 / 6.67 ≈ 15.

[0067] S400. If the safety factor is greater than the first preset value, it is determined that the large diameter-to-thickness ratio optical element processing and testing fixture meets the safety and strength requirements under the corresponding hoisting conditions.

[0068] For example, the first preset value can be set according to industry standards, engineering experience, and the value and risk level of the component. For example, the first preset value in this embodiment is 10, ensuring that even if unforeseen additional loads or minor material defects are encountered in actual use, there is still sufficient safety buffer to ensure that the optical component is not damaged.

[0069] For example, if the first preset value is 10 and the safety factor calculated by simulation is 15, then the tooling is deemed to have passed the safety verification under this lifting condition. Conversely, if the safety factor is only 8, it is deemed to have failed, and the tooling or clamping scheme needs to be redesigned until the simulation result meets the preset value.

[0070] Please see Figure 14 In some embodiments, the verification method further includes detection accuracy verification, which includes steps S500-S700: S500 performs finite element mechanical simulation on the assembly formed after the optical element is clamped by the large diameter-to-thickness optical element processing and testing fixture, and obtains the stress and deformation data of the optical element.

[0071] For example, the detection accuracy verification in this embodiment is performed under the condition that the optical element is in the posture to be detected during the detection support operation. For example, after finite element mechanical simulation, the displacement field data of each node on the optical surface of the optical element can be obtained, that is, its three-dimensional deformation, based on which the stress deformation data of the optical element can be obtained.

[0072] S600: Determine the additional optical wavefront distribution of optical elements caused by tooling clamping based on stress deformation data.

[0073] For example, the optical surface nodal displacement data output by the finite element software is imported into the optical design and analysis software through coordinate mapping and data processing. In the optical software, the deformed surface shape is defined as the optical surface. An ideal plane wave or spherical wave is set as the incident light. The wavefront phase distribution of the light after passing through the deformed optical surface is calculated by the optical design software. The phase difference between this wavefront phase distribution and the wavefront phase distribution of the light after passing through the ideal undeformed surface is the optical additional wavefront distribution, which reflects the influence of surface deformation on the optical path.

[0074] S700. If the root mean square value of the optical additional wavefront distribution is less than the second preset value, it is determined that the large diameter-to-thickness ratio optical element processing and testing fixture meets the testing accuracy requirements.

[0075] For example, in this embodiment, the second preset value is one-fifth of the required surface accuracy of the optical element.

[0076] The above examples are merely illustrative of the technical content of the present invention to facilitate easier understanding by the reader, but do not imply that the implementation of the present invention is limited to these examples. Any technical extensions or re-creations made based on the present invention are protected by the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A machining and inspection fixture for large-diameter-to-thickness optical elements, used for clamping optical elements, characterized in that, The optical element includes a body and a clamping part. The clamping part is connected to the outer peripheral side of the body. The clamping part has a first end face and a second end face disposed opposite to each other, and a first outer peripheral side face connected between the first end face and the second end face. The large-diameter-to-thickness ratio optical element processing and testing fixture includes: A first clamping member and a first washer, wherein the first clamping member is provided with a first clamping surface corresponding to the first end face, and the first washer is disposed on the first clamping surface; The second clamping member and the second washer are provided with a second clamping surface corresponding to the second end face, and the second washer is provided on the second clamping surface; The first clamping member and the second clamping member are detachably connected, and a clamping space for accommodating the clamping part is formed between the first clamping surface and the second clamping surface.

2. The large diameter-to-thickness ratio optical element processing and inspection fixture according to claim 1, characterized in that, The large diameter-to-thickness ratio optical element processing and testing fixture also includes a third washer; the first clamping member is also provided with a first inner peripheral side corresponding to the first outer peripheral side, and the third washer is provided on the first inner peripheral side.

3. The large diameter-to-thickness ratio optical element processing and inspection fixture according to claim 2, characterized in that, The second clamping member is further provided with a second inner peripheral side corresponding to the first outer peripheral side, the first inner peripheral side and the second inner peripheral side are spliced ​​together, and the third washer is provided on the first inner peripheral side and the second inner peripheral side.

4. The large diameter-to-thickness ratio optical element processing and inspection fixture according to claim 1, characterized in that, The first clamping surface is provided with a first mounting groove, and a portion of the first washer is embedded in the first mounting groove; And / or, the second clamping surface is provided with a second mounting groove, and a portion of the second washer is embedded in the second mounting groove.

5. The large diameter-to-thickness ratio optical element processing and inspection fixture according to any one of claims 1-4, characterized in that, The body portion has a second outer peripheral side surface adjacent to the first end face, and an optical curved surface adjacent to the second outer peripheral side surface; The first clamping member is further provided with a third inner peripheral side corresponding to the second outer peripheral side, and a transition surface adjacent to the third inner peripheral side, the transition surface having the same curvature as the optical surface.

6. The large diameter-to-thickness ratio optical element processing and inspection fixture according to any one of claims 1-4, characterized in that, The second clamping member is provided with a hanging hole, which is used to connect with the hook of the testing bracket.

7. The large diameter-to-thickness ratio optical element processing and inspection fixture according to any one of claims 1-4, characterized in that, The large diameter-to-thickness ratio optical element processing and testing fixture also includes a first lifting ring, which is connected to the second clamping member, and the central axis of the lifting hole formed by the first lifting ring is perpendicular to the second clamping surface.

8. The large diameter-to-thickness ratio optical element processing and inspection fixture according to any one of claims 1-4, characterized in that, The large diameter-to-thickness ratio optical element processing and testing fixture also includes a second lifting ring, which is connected to the second clamping member, and the central axis of the lifting hole formed by the second lifting ring is parallel to the second clamping surface.

9. A method for verifying the use of the large diameter-to-thickness ratio optical element processing and inspection fixture according to any one of claims 1-8, characterized in that, The verification method includes security strength verification, which includes: Finite element mechanical simulation was performed on the assembly formed by clamping the optical element with the large diameter-to-thickness ratio optical element processing and testing fixture under the hoisting condition. The hoisting condition includes at least a horizontal hoisting state and a vertical hoisting state. The maximum working stress in the optical element is determined based on the simulation results of the finite element mechanical simulation. The safety factor of the optical element is determined based on the maximum working stress and the material strength limit of the optical element. If the safety factor is greater than the first preset value, then the large diameter-to-thickness optical element processing and testing fixture is determined to meet the safety and strength requirements under the corresponding hoisting conditions.

10. The verification method according to claim 9, characterized in that, The verification method further includes detection accuracy verification, which includes: Finite element mechanical simulation was performed on the assembly formed after the large diameter-to-thickness optical element was clamped by the processing and testing fixture to obtain the stress and deformation data of the optical element. The optical additional wavefront distribution generated by the tooling clamping of the optical element is determined based on the stress deformation data. If the root mean square value of the optical additional wavefront distribution is less than the second preset value, then the large diameter-to-thickness optical element processing and testing fixture is determined to meet the testing accuracy requirements.

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