Rapid cooling lens mounting structure with optical reference and heat transmission separated and implementation method thereof

Abstract

The invention discloses an optical reference and heat transmission separated rapid cooling lens mounting structure and an implementation method, which are suitable for a rapid cooling deep hypothermia cold optical system. The device is composed of a pressing ring, a lens holder annular surface heat conduction layer, a lens annular surface heat conduction layer, a lens, a fixing support, a lens holder and a pressing ring screw. An optical reference installation and heat transmission separation structure is arranged, and a flexible structure and a specific design method are introduced, so that on the premise that the optical reference and the optical precision are ensured, the problem of low-temperature shrinkage resistance in the radial direction of lens installation is solved, and the influence of the installation structure on the optical performance of the lens is avoided; by reserving a heat transfer crimping surface and designing heat transfer, quantitative control of rapid cooling time is achieved, and low-stress installation and rapid cooling of the profound hypothermia lens are achieved. The device is simple in structure, convenient to operate, good in compatibility and high in reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of deep cryogenic lens installation, and specifically to a fast cooling lens installation structure with separated optical reference and heat transmission and an implementation method thereof, which is suitable for assembly of cold optical and low temperature optical machine structures requiring fast cooling. Background Art

[0002] In order to better meet the infrared detection needs of deep space stars and low-energy targets in space, high sensitivity and low noise are inevitable development trends. Cold optical technology is one of the effective means to achieve this target detection. Cold optical technology is to place the optical elements and detectors of the infrared optical system in the rear optical path assembly (cold box / dewar), and reduce the temperature of the optical elements and detectors to the operating temperature through a deep low-temperature cold source, thereby effectively suppressing the influence of thermal radiation and stray light of the optical elements and their supporting structures on the detection performance, and greatly reducing the background noise. At the same time, with the development of moving target and weak target detection, the demand for rapid cooling of the optical-mechanical system has gradually emerged. In the observation of certain infrared detection payloads, the system requires the low-temperature optical-mechanical system to be cooled to the required temperature in a short time, so as to reduce the instrument background in a short time and realize weak target detection at the same time.

[0003] A Chinese invention patent with announcement number CN103389554B discloses a multi-point support structure for an optical element with adjustable height. The solution is that a plurality of flexible support components are evenly distributed and fixed on the inner circumferential surface of the frame, and the optical element is arranged on the plurality of flexible support components. The flexible support components are composed of a flexible support block, a differential head and a restoring force spring. The differential head is fixed on the upper part of the flexible support block, and the restoring force spring is fixed on the upper part of the flexible support block and is located in the direction opposite to the differential head.

[0004] A Chinese invention patent with announcement number CN108227111B discloses a method for reducing the bonding stress of a large-aperture aspheric hollow reflector. During assembly, the main reflector and the main mirror frame are supported by a support platform, the main mirror pressure plate and the pressure plate rubber pad are used to assist in positioning the main mirror, and the main reflector is fixed by injecting glue through the glue injection hole.

[0005] At present, domestic patents on lens groups focus on the innovation of low-stress mounting structures of lens groups, and generally use micro-flexible structures to reduce the impact of mounting stress on the lens. At present, domestic and foreign patents and articles have not reported on the fast cooling lens group mounting structure.

[0006] The processing and adjustment of optical components and supporting structures need to be carried out at room temperature, while the actual working environment of optical components and supporting structures is in the range of 77K-200K, with a temperature change of up to 200K. Generally speaking, the performance parameters of materials such as CTE (coefficient of thermal expansion), specific heat capacity, refractive index, etc. vary from material to material, and these performance parameters change nonlinearly during the cooling process. The difference in geometric shape change is mainly attributed to the different CTE of the material. It can cause positional errors and deformation of optical components, and even damage optical components. The difference in optical change is not only affected by the difference in geometric shape change of the optical surface of the optical component and the change in the position of the optical component, but also by the change in the refractive index of the optical material. Summary of the invention

[0007] The purpose of the present invention is to provide a fast cooling lens mounting structure and an implementation method with separated optical reference and heat transfer, which solves the problem that the prior art focuses on the innovation of the low stress mounting structure of the lens group but does not explain how to achieve fast cooling, and at the same time ignores the defect that fast temperature changes, especially the influence of low temperature on the lens group structure.

[0008] To achieve the above object, the technical solution of the present invention is:

[0009] A fast cooling lens installation structure with separated optical reference and heat transmission, comprising a pressing ring, a lens and a lens seat, wherein the lens seat is provided with an installation groove, and the lens is arranged in the installation groove;

[0010] A fixed support is also provided in the mounting groove, and the lens is provided on the fixed support;

[0011] The pressing ring is cylindrical with a folded edge, the folded edge is the ring surface of the pressing ring lens seat, and the cylinder wall is the pressing ring lens ring; the pressing ring is inserted into the installation groove, the ring surface of the pressing ring lens seat is mounted on the upper surface of the side wall of the installation handle, and the pressing ring lens ring is pressed against the upper surface of the lens;

[0012] An annular lens seat annular surface heat conduction layer is arranged between the pressure ring lens seat annular surface and the upper surface of the mounting groove side wall, and an annular lens annular surface heat conduction layer is arranged between the pressure ring lens ring and the lens.

[0013] The fixed support is in a circular ring shape and comprises a flexible support and a non-flexible support, wherein the flexible support is arranged at intervals on the upper surface of the non-flexible support.

[0014] The pressure ring, fixed support and lens holder are made of high thermal conductivity material, the thermal conductivity of which is greater than 150W / (m﹒K) and the expansion coefficient is less than 8.6×10 -6 / K;

[0015] A through hole is arranged on the annular surface of the pressure ring lens seat, and a screw hole is arranged correspondingly on the lens seat wall. The pressure ring screw fixes the pressure ring on the lens seat through the through hole and the screw hole.

[0016] The lens seat annular surface heat-conducting layer and the lens annular surface heat-conducting layer are made of a material with a thermal conductivity greater than 70 W / (m﹒K).

[0017] The lens is convex, comprising a lens supporting surface and a lens heat conducting surface, the lens annular surface heat conducting layer is arranged on the lens heat conducting surface, and the lens supporting surface is arranged on the fixed support.

[0018] The method for confirming the diameter D2 of the lens thermal conductive surface is as follows:

[0019]

[0020] Wherein, Cv is the specific heat capacity of the lens, m is the mass of the lens, k is the thermal conductivity of the lens, H2 is the thickness of the lens, T is the cooling time of the lens, D1 is the inner diameter of the pressing ring, and D3 is the diameter of the lens.

[0021] The depth H5 of the mounting groove of the lens seat is equal to the sum of the depth H1 of the lens ring of the pressing ring, the edge thickness H2 of the lens and the thickness H3 of the fixed support, that is, H5=H1+H2+H3.

[0022] A method for implementing a fast cooling lens mounting structure with optical reference and heat transmission separated.

[0023] Here’s how to do it:

[0024] Step 1: glue and align the lens seat ring surface heat-conducting layer and the pressure ring lens seat ring surface, and the lens ring surface heat-conducting layer and the pressure ring lens ring respectively under the centering instrument, and set them aside after curing;

[0025] Step 2: align the fixed support and the lens holder by gluing and curing them under the centering instrument;

[0026] Step 3, using three coordinates to measure the shape and position tolerances of the fixed support and the lens seat after curing in step 2, and use a machine tool to fine-tune to the shape and position tolerances required by optics, and ensure that the depth H5 of the mounting groove of the lens seat is equal to the sum of the depth H1 of the lens ring of the pressing ring, the edge thickness H2 of the lens, and the thickness H3 of the fixed support;

[0027] Step 4: Clean the fixed support and lens holder after fine-tuning in step 3 with acetone and alcohol ultrasonically, and then put them into an oven for drying;

[0028] Step 5, put the lens into the mounting groove of the lens holder processed in step 4 under the centering instrument, and center and glue and cure;

[0029] Step six, insert the pressure ring that has been cured in step one into the installation groove and fix it on the lens seat, and the pressure ring fixes the lens on the lens seat.

[0030] A through hole is set on the annular surface of the pressure ring lens seat, and a screw hole is set correspondingly on the lens seat; step six, insert the pressure ring into the installation groove, align the through hole on the annular surface of the pressure ring lens seat with the screw hole on the lens seat, and fix it with the pressure ring screw; first fix it with 4cn torque, then loosen it, tighten it with 2cn torque, and then back off 1 / 8 turn, and fill the pressure ring screw and the pressure ring with glue and solidify it.

[0031] The present invention conducts mechanical and thermal design for a lens mounting structure with rapid cooling. On the premise of ensuring the optical reference and optical accuracy, a high thermal conductivity material is selected as the material of the lens seat and the pressure ring. A flexible structure is adopted on the mounting surface of the lens and a heat transfer pressing surface is reserved on the front surface of the lens to separate the optical reference from the heat transfer, thereby realizing a low-stress, rapid cooling lens mounting structure.

[0032] The advantages of the present invention are: 1. The present invention has a simple structure, convenient operation and low cost; 2. The diameter of the lens bonding surface in the present invention can be calculated according to the cooling time to guide the lens design; 3. The pressure ring, fixed support and lens seat in the present invention are all made of high thermal conductivity materials, and the heat transfer interface is made of high thermal conductivity materials to achieve rapid cooling of the lens installation structure; 4. Under the premise of ensuring the optical reference and ensuring the optical accuracy, the present invention sets a flexible support in the fixed support to solve the radial resistance to low temperature shrinkage of the lens installation, which can offset the deformation of the lens in the radial direction, thereby achieving low-stress installation of the lens and avoiding the influence of the installation structure on the optical performance of the lens; 5. In order to achieve rapid cooling, a heat transfer pressing surface is reserved on the front surface of the lens. The cross-sectional area of ​​the lens pressing surface is calculated according to the heat flux density, cooling time and specific heat capacity to solve the quantitative controllable rapid cooling; 6. The lens group assembled by the present invention can be applied to the 80K temperature zone, and also to the lower temperature zone below 80K. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a diagram of the lens installation structure of the present invention;

[0034] Figure 2 It is a schematic diagram of the structure of the pressing ring of the present invention;

[0035] Figure 3 This is a structural diagram of the heat-conducting layer of the annular surface of the lens holder of the present invention;

[0036] Figure 4 It is a structural diagram of the heat-conducting layer of the lens annulus of the present invention.

[0037] Figure 5 2 is a diagram showing the structure of the lens of the present invention.

[0038] Figure 6 It is a fixed support structure diagram of the present invention.

[0039] Figure 7 It is a cross-sectional view of the fixed support of the present invention.

[0040] Figure 8 It is a structural diagram of the lens holder of the present invention.

[0041] In the figure: 1-pressing ring; 101-pressing ring lens seat ring surface; 102-pressing ring lens ring; 103-through hole; 2-lens seat ring surface heat conducting layer; 3-lens seat ring surface heat conducting layer; 4-lens, 401-lens support surface; 402-lens heat conducting surface; 5-fixed support; 501-flexible support; 502-non-flexible support; 6-lens seat; 601-mounting groove; 602-screw hole; 7-pressing ring screw. DETAILED DESCRIPTION

[0042] The present invention is further described below in conjunction with the accompanying drawings, which are only used for exemplary description and cannot be understood as limiting the present invention.

[0043] In order to more concisely describe the present embodiment, some parts known to those skilled in the art but not related to the main content of the present invention are omitted in the drawings or descriptions. In addition, for the convenience of description, some parts in the drawings are omitted, enlarged or reduced, but they do not represent the size or entire structure of the actual product.

[0044] The present invention discloses a fast cooling lens installation structure with separated optical reference and heat transmission, such as Figure 1-8 As shown, it includes a pressing ring 1 , a lens 4 and a lens seat 6 . The lens seat 6 is provided with a mounting groove 601 , and the lens 4 is arranged in the mounting groove 601 .

[0045] A fixed support 5 is also disposed in the mounting groove 601 , and the lens 4 is disposed on the fixed support 5 .

[0046] like Figure 1 , Figure 2 As shown, the pressure ring 1 is cylindrical with a folded edge, the folded edge is the pressure ring lens seat ring surface 101, and the cylinder wall is the pressure ring lens ring 102; the pressure ring 1 is inserted in the installation groove 601, the pressure ring lens seat ring surface 101 is mounted on the upper surface of the side wall of the installation groove 601, and the pressure ring lens ring 102 is pressed against the upper surface of the lens 4; the pressure ring lens seat ring surface 101 is provided with a through hole 103, and the lens seat 6 is correspondingly provided with a screw hole 602, and the pressure ring screw 7 fixes the pressure ring 1 on the lens seat 6 through the through hole 103 and the screw hole 602.

[0047] Furthermore, the pressing ring 1, the fixed support 5 and the lens holder 6 are made of a high thermal conductivity material, the thermal conductivity of which is greater than 150 W / (m﹒K) and the expansion coefficient is less than 8.6×10-6 / K. SiCp / Al is preferred, with a thermal conductivity of 210 W / (m﹒K) and an expansion coefficient of 7.3×10-6 / K. Rapid cooling can be achieved.

[0048] An annular lens seat annular surface heat conducting layer 2 is arranged between the pressing ring lens seat annular surface 101 and the upper surface of the side wall of the mounting groove 601 , and an annular lens annular surface heat conducting layer 3 is arranged between the lower surface of the pressing ring lens ring 102 and the lens 4 .

[0049] The lens seat annular surface heat-conducting layer 2 and the lens annular surface heat-conducting layer 3 are made of a material with a thermal conductivity greater than 70W / (m﹒K), and the thickness of the two is equal, both of which are 0.2mm-0.4mm. In is preferably used. Rapid cooling can be achieved.

[0050] Furthermore, if Figure 3 As shown, the width W3 of the lens seat annular surface heat conducting layer 2 is 0.2mm-0.4mm smaller than the width W1 of the pressure ring lens seat annular surface 101. Optionally, the width W1 of the pressure ring lens seat annular surface 101 is 5mm, and the width W3 of the lens seat annular surface heat conducting layer 2 is 4.8mm.

[0051] like Figure 4 As shown, the width W4 of the lens ring surface heat-conducting layer 3 is 0.2mm-0.4mm smaller than the width W2 of the pressure ring lens ring 102. Optionally, the width W2 of the pressure ring lens ring 102 is 3mm, and the width W4 of the lens ring surface heat-conducting layer 3 is 2.8mm.

[0052] like Figure 5 As shown, the lens 4 is convex, made of ZnSe material, including a lens support surface 401 and a lens heat-conducting surface 402, a lens annular surface heat-conducting layer 3 is arranged between the lower surface of the pressure ring lens ring 102 and the lens heat-conducting surface 402, the lens support surface 401 is arranged on the fixed support 5, and the flexible support 501 solves the radial low-temperature shrinkage resistance of the lens 4 when it is installed, and avoids the influence of the installation structure on the optical performance of the lens 4. The arrangement of the lens heat-conducting surface 402 and the lens annular surface heat-conducting layer 3 can achieve rapid cooling.

[0053] The method for confirming the diameter D2 of the lens heat conducting surface 402 is as follows:

[0054] The cross-sectional area A of the lens heat conducting surface 402 is determined based on the specific heat capacity Cv, mass m, thermal conductivity k, thickness H2 of the lens 4, and cooling time T. A=C v ·m·H2k·T;

[0055] The diameter D2 of the lens heat conducting surface 402 is calculated according to the diameter D3 of the lens 4, the inner diameter D1 of the pressing ring 1 and the cross-sectional area A of the lens heat conducting surface 402.

[0056] like Figure 6 , Figure 7As shown, the fixed support 5 is annular, including a flexible support 501 and a non-flexible support 502, and the flexible support 501 is spaced apart on the upper surface of the non-flexible support 502. Preferably, the fixed support 5 is made of a high thermal conductivity material, whose thermal conductivity is required to be greater than 150W / (m﹒K) and whose expansion coefficient is less than 8.6×10 -6 / K, wherein the thickness of the non-flexible support 502 is 0.5 mm-1 mm less than the thickness of the flexible support 501. Optionally, the thickness of the flexible support 501 is 1 mm, the thickness of the non-flexible support 502 is 2 mm, and the total thickness of the fixed support 5 is 3 mm.

[0057] like Figure 1 , Figure 8 As shown, the depth H5 of the mounting groove 601 of the lens holder 6 is equal to the sum of the depth H1 of the pressing ring lens ring 102 of the pressing ring 1, the edge thickness H2 of the lens 4 and the thickness H3 of the fixed support 5, that is, H5=H1+H2+H3.

[0058] The above Figure 1-8 A method for implementing a fast cooling lens mounting structure with optical reference and heat transmission separated is provided, and the specific steps are as follows:

[0059] Step 1: glue and align the lens seat annular surface heat-conducting layer 2 and the pressing ring lens seat annular surface 101, the lens annular surface heat-conducting layer 3 and the pressing ring lens ring 102 respectively under the alignment instrument, and set them aside after curing;

[0060] Step 2: glue and align the fixed support 5 and the lens holder 6 under the centering instrument, and then cure them;

[0061] Step 3, using three coordinates to measure the shape and position tolerances of the fixed support 5 and the lens holder 6 after curing in step 2, and use a machine tool to fine-tune to the shape and position tolerances required by optics, and ensure that the depth H5 of the mounting groove 601 of the lens holder 6 is equal to the sum of the depth H1 of the pressing ring lens ring 102 of the pressing ring 1, the edge thickness H2 of the lens 4 and the thickness H3 of the fixed support 5;

[0062] Step 4, clean the fixed support 5 and lens holder 6 after fine-tuning in step 3 with acetone and alcohol ultrasonically, and then put them into an oven for drying;

[0063] Step 5: Put the lens 4 into the mounting groove 601 of the lens holder 6 processed in step 4 under the centering instrument, and center and glue and cure;

[0064] Step six: insert the pressing ring 1 that has been cured in step one into the mounting groove 601 and fix it on the lens holder 6 . The pressing ring 1 fixes the lens 4 on the lens holder 6 .

[0065] Furthermore, a through hole 103 is provided on the annular surface 101 of the pressure ring lens seat, and a screw hole 602 is correspondingly provided on the lens seat 6; step six, after the pressure ring 1 is inserted into the mounting groove 601, the through hole 103 of the annular surface 101 of the pressure ring lens seat and the screw hole 602 on the lens seat 6 are aligned and fixed with the pressure ring screw 7; first fix it with a 4cn torque, then loosen it, tighten it with a 2cn torque, and then retreat 1 / 8 of a turn, and fill the pressure ring screw 7 and the pressure ring 1 with glue and solidify it.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. That is, any equivalent changes and modifications made according to the content of the patent application scope of the present invention should be within the technical scope of the present invention.

Claims

1. A fast cooling lens mounting structure with separated optical reference and heat transmission, comprising a pressing ring (1), a lens (4) and a lens seat (6), wherein the lens seat (6) is provided with a mounting groove (601), and the lens (4) is arranged in the mounting groove (601); Features: A fixed support (5) is also provided in the mounting groove (601), and the lens (4) is provided on the fixed support (5); The pressing ring (1) is cylindrical with a folded edge, the folded edge is a pressing ring lens seat annular surface (101), and the cylinder wall is a pressing ring lens ring (102); the pressing ring (1) is inserted into the mounting groove (601), the pressing ring lens seat annular surface (101) is mounted on the upper surface of the side wall of the mounting groove (601), and the pressing ring lens ring (102) is pressed against the upper surface of the lens (4); An annular lens seat annular surface heat conduction layer (2) is arranged between the pressure ring lens seat annular surface (101) and the upper surface of the side wall of the mounting groove (601), and an annular lens annular surface heat conduction layer (3) is arranged between the pressure ring lens ring (102) and the lens (4).

2. The fast cooling lens mounting structure with separated optical reference and heat transmission according to claim 1, characterized in that: The fixed support (5) is in the shape of a circular ring and comprises a flexible support (501) and a non-flexible support (502). The flexible support (501) is arranged on the upper surface of the non-flexible support (502) at intervals.

3. The fast cooling lens mounting structure with separated optical reference and heat transmission according to claim 2, characterized in that: The pressing ring (1), the fixed support (5) and the lens seat (6) are made of a high thermal conductivity material, the thermal conductivity of which is greater than 150 W / (m﹒K) and the expansion coefficient is less than 8.6×10 -6 / K; The annular surface (101) of the pressure ring lens seat is provided with a through hole (103), and the lens seat (6) is correspondingly provided with a screw hole (602). The pressure ring screw (7) fixes the pressure ring (1) on the lens seat (6) through the through hole (103) and the screw hole (602).

4. The fast cooling lens mounting structure with separated optical reference and heat transmission according to claim 3 is characterized in that: The lens seat annular surface heat-conducting layer (2) and the lens annular surface heat-conducting layer (3) are made of a material with a thermal conductivity greater than 70 W / (m﹒K).

5. The fast cooling lens mounting structure with separated optical reference and heat transmission according to claim 4, characterized in that: The lens (4) is convex, comprising a lens support surface (401) and a lens heat conduction surface (402); the lens annular heat conduction layer (3) is arranged on the lens heat conduction surface (402); and the lens support surface (401) is arranged on the fixed support (5).

6. The fast cooling lens mounting structure with separated optical reference and heat transmission according to claim 5, characterized in that: The method for confirming the diameter D2 of the lens heat conducting surface (402) is as follows: In the formula, Cv is the specific heat capacity of the lens (4), m is the mass of the lens (4), k is the thermal conductivity of the lens (4), H2 is the thickness of the lens (4), T is the cooling time of the lens (4), D1 is the inner diameter of the pressing ring (1), and D3 is the diameter of the lens (4).

7. The fast cooling lens mounting structure with separated optical reference and heat transmission according to claim 5, characterized in that: The depth H5 of the mounting groove (601) of the lens seat (6) is equal to the sum of the depth H1 of the pressing ring lens ring (102) of the pressing ring (1), the edge thickness H2 of the lens (4) and the thickness H3 of the fixed support (5), that is, H5=H1+H2+H3.

8. The method for implementing the fast cooling lens mounting structure with separated optical reference and heat transmission as claimed in any one of claims 1 to 7, characterized in that: Here’s how to do it: Step 1, under the alignment instrument, respectively glue and align the lens seat annular surface heat-conducting layer (2) and the pressure ring lens seat annular surface (101), and the lens annular surface heat-conducting layer (3) and the pressure ring lens ring (102), and set them aside for use after curing; Step 2, gluing and aligning the fixed support (5) and the lens holder (6) under an alignment instrument, and curing; Step 3, using three coordinates to measure the shape and position tolerances of the fixed support (5) and the lens seat (6) after curing in step 2, and using a machine tool to fine-tune to the shape and position tolerances required by optics, and ensuring that the depth H5 of the mounting groove of the lens seat (6) is equal to the sum of the depth H1 of the pressing ring lens ring (102) of the pressing ring (1), the edge thickness H2 of the lens (4) and the thickness H3 of the fixed support (5); Step 4, clean the fixed support (5) and lens holder (6) after fine-tuning in step 3 with acetone and alcohol ultrasonically, and then put them into an oven for drying; Step 5, placing the lens (4) into the mounting groove (601) of the lens holder (6) processed in step 4 under a centering instrument, and centering and gluing and curing; Step six, insert the pressure ring (1) that has been cured in step one into the installation groove (601) and fix it on the lens seat (6), and the pressure ring (1) fixes the lens (4) on the lens seat (6).

9. The method for implementing the fast cooling lens mounting structure with separated optical reference and heat transmission according to claim 8, characterized in that: The ring surface (101) of the pressure ring lens seat is provided with a through hole (103), and the lens seat (6) is correspondingly provided with a screw hole (602); Step 6, the pressure ring (1) is inserted into the mounting groove (601), the through hole (103) of the ring surface (101) of the pressure ring lens seat is aligned with the screw hole (602) on the lens seat (6), and fixed with a pressure ring screw (7); first fix with a torque of 4cn, then loosen and tighten with a torque of 2cn, then withdraw 1 / 8 turn, and glue the pressure ring screw (7) and the pressure ring (1) for curing.

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