Cold contraction supporting structure for Dewar packaging

Abstract

The invention discloses a cold shrinkage supporting structure for Dewar packaging, which comprises a supporting column and a cold shrinkage structure, and is characterized in that the cold shrinkage structure is arranged on the supporting column in a clearance manner; the cold shrinkage structure comprises a cold shrinkage frame and a cold shrinkage rod, the cold shrinkage rod is arranged in the cold shrinkage frame, and the material expansion coefficient of the cold shrinkage frame is larger than that of the cold shrinkage rod; the cold contraction structure is arranged on the installation part, and a gap is formed between the cold contraction structure and the installation part. When the thermal contraction structure is applied to an infrared detector, the rigid support of the Dewar at room temperature and the low stress and low heat leakage effects of the Dewar structure when the infrared detector works at low temperature are realized through the characteristic that the space infrared detector Dewar has no mechanical environment under the low-temperature working condition and by utilizing the thermal contraction size change of the thermal contraction structure at low temperature.

Description

Technical Field

[0001] The invention relates to the technical field of infrared detector dewar packaging, in particular to a cold shrinkage support structure for dewar packaging, which is suitable for strengthening the mechanical structure of the infrared detector dewar and suppressing the heat leakage of the dewar when working at low temperature. Background Art

[0002] High spatial resolution infrared cameras are the core components of infrared remote sensing instruments. There are generally two ways to improve spatial resolution. One is to stitch and fuse images after multiple imaging; the other is to increase the number of infrared sensitive elements, that is, for remote sensing instruments at the same height and the same swath, the more sensitive elements, the higher the spatial resolution. The expansion of detector scale and the corresponding larger infrared focal plane dewar preparation technology are of great significance in the field of aerospace and aviation infrared. With the expansion of wavelengths to long waves and the improvement of detection sensitivity, ultra-long linear array infrared focal plane detectors must work at deep low temperatures, which also means that most of their applications use dewar-packaged infrared focal plane dewar components.

[0003] Traditional dewar structures are generally mechanically strengthened by supporting structures, that is, supporting columns are installed between the infrared detector substrate and the shell structure, and the supporting columns are required to provide mechanical support for the infrared detector while having good thermal insulation performance. Since the supporting columns connect the detector substrate and the shell, when the detector works at low temperatures, the supporting columns will transfer the cold at the detector substrate to the shell, resulting in heat leakage. At the same time, when the detector works at low temperatures, the internal structure of the dewar will produce a certain degree of cold shrinkage deformation due to the temperature drop. Due to the rigid fixation of the supporting columns, the cold end structure of the detector will be additionally deformed by force, which will bring additional structural stress to the detector. Considering that the infrared detector dewar for space applications has high requirements for structural strength only in ground mechanical experiments and rocket launch stages, and the infrared detector is at room temperature under mechanical environmental conditions. The infrared detector dewar requires a supporting structure that has high structural support strength at room temperature and can be separated from the shell by supporting low-temperature cold shrinkage when the detector works at low temperatures. Summary of the invention

[0004] The purpose of the present invention is to provide a cold shrinkage support structure for Dewar packaging, which solves the problem of heat leakage of the support column at low temperature in the Dewar support structure in the prior art, and the problem that when working at low temperature, over-constraint will be generated due to the rigid fixation of the support, resulting in additional force and deformation of the cold end structure of the detector, which brings additional structural stress to the detector.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A cold shrink support structure for Dewar packaging, comprising a support column and a cold shrink structure, wherein a gap of the cold shrink structure is arranged on the support column; the support column comprises a base, a heat insulation column and a mounting portion;

[0007] The cold shrink structure includes a cold shrink frame and a cold shrink rod, the cold shrink rod is arranged in the cold shrink frame, and the material expansion coefficient of the cold shrink frame is greater than the material expansion coefficient of the cold shrink rod;

[0008] The cold shrink structure is arranged on the installation part, and there is a gap between the cold shrink structure and the installation part.

[0009] The shrink structure comprises two or more parallel connected rhombus shrink frames, each of which has a shrink rod fixedly arranged in it, and the shrink rod is arranged between two apex angles corresponding to the long diagonal line of the rhombus.

[0010] The mounting portion is provided with a mounting seat wall; the shrink frame is fixedly connected to the mounting seat wall with a gap.

[0011] The mounting part is a rectangular parallelepiped surrounded by three mounting part walls with one end open, and each mounting seat wall is provided with a screw hole; at room temperature, the screws pass through the screw holes and hit the edge of the shrink frame, so that the bottom of the shrink structure does not contact the mounting seat, and the gap of the shrink frame is fixed in the mounting part.

[0012] The gap between the mounting base wall and the shrink frame is 1mm-5mm.

[0013] The shrinkage frame of the shrinkage structure is made of aluminum or copper with a high expansion coefficient; the shrinkage rod is made of Kovar, Invar, titanium alloy or molybdenum with a low expansion coefficient.

[0014] The support column is made of titanium alloy, stainless steel or fiberglass with low thermal conductivity.

[0015] Each support column is provided with a cold shrink structure.

[0016] The beneficial effects of the present invention are:

[0017] 1. The support column ensures that the infrared detector dewar has good structural rigidity at room temperature; 2. The support structure has temperature adaptive characteristics, achieving effective rigid support at room temperature and achieving thermal insulation after low-temperature shrinkage; 3. When used in the detector dewar package, the height of the cold finger is designed to ensure that the bottom of the shrink structure has no mechanical contact with the support column. Under the low temperature state of the liquid nitrogen temperature zone (-210℃--196℃), the shrink frame is separated from the screws after shrinkage, thereby achieving the separation of the entire shrink structure from the wall of the mounting part and no mechanical contact, directly avoiding the heat leakage problem of the support column under the low-temperature working state of the detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the cold shrinkage support structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the support column structure of the present invention;

[0020] Figure 3It is a schematic diagram of the cold shrink frame structure of the present invention;

[0021] Figure 4 It is a schematic diagram of a diamond-shaped cold shrink frame unit of the present invention;

[0022] In the figure: 1-support column; 11-base; 12-insulation column; 13-mounting seat; 131-mounting seat wall; 2-shrinkage structure; 21-shrinkage frame; 22-shrinkage rod. DETAILED DESCRIPTION

[0023] 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.

[0024] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] 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.

[0026] The present invention will now be further described with reference to the embodiments and the accompanying drawings:

[0027] The present invention relates to a cold shrink support structure for Dewar packaging, such as Figure 1 As shown, it includes a support column 1 and a shrink structure 2, and the shrink structure 2 is arranged on the support column 1 with a gap.

[0028] The lower end of the support column 1 can be fixed to the Dewar shell; the upper end of the support column 1 is provided with a shrink structure 2, which can be fixedly connected to the Dewar infrared detector substrate or other components with temperature changes.

[0029] The support column 1 provides mechanical support for the infrared detector and is required to have good thermal insulation performance. The support column 1 is usually made of titanium alloy, stainless steel or fiberglass with low thermal conductivity.

[0030] like Figure 2 As shown, the support column 1 includes a base 11 , a heat-insulating column 12 and a mounting portion 13 ; the base 11 is fixedly connected to the Dewar, and the cold shrink structure 2 is arranged on the mounting portion 13 .

[0031] like Figure 3As shown, the shrink structure 2 includes a shrink frame 21 and a shrink rod 22. The shrink rod 22 is fixedly arranged in the shrink frame 21. The material expansion coefficient of the shrink frame 21 is greater than the material expansion coefficient of the shrink rod 22. Usually, the shrink frame 21 of the shrink structure 2 is made of aluminum or copper with a high expansion coefficient; the shrink rod 22 is made of Kovar, Invar, titanium alloy or molybdenum with a low expansion coefficient. In this way, under low temperature conditions, the shrink rod 22 can amplify the shrink displacement of the shrink structure 2 when it shrinks itself, so that the shrink structure 2 is disconnected from the support column 1.

[0032] like Figure 2 As shown, the mounting portion 13 has a mounting seat wall 131; preferably, the mounting portion 13 is a rectangular parallelepiped surrounded by three mounting portion walls 131 with one end open, and each mounting seat wall 131 is provided with a screw hole; at room temperature, Figure 1 As shown, Figure 3 The shrink structure 2 shown is placed in the mounting portion 13, and a tightening screw is passed through the screw hole to contact the edge of the shrink frame 21, so that the bottom of the shrink structure 2 does not contact the mounting seat 13, and the shrink frame 21 is fixed in the mounting portion 13. It is used in the detector dewar package, and cooperates with the cold finger. The height of the cold finger is designed to ensure that the bottom of the shrink structure 2 does not have mechanical contact with the bottom of the mounting portion 131. Under the low temperature state of the liquid nitrogen temperature range (-210℃--196℃), the shrink frame 21 is detached from the screw after shrinking, so that the entire shrink structure 2 is detached from the mounting portion 131 and has no mechanical contact, directly avoiding the heat leakage problem of the support column under the low temperature working state of the detector.

[0033] The shrink frame 21 is fixedly connected with the mounting seat wall 131 with a gap. The gap between the mounting seat wall 131 and the shrink frame 21 is between 1 mm and 5 mm.

[0034] The above structure enables the support column 1 to be effectively separated from the infrared detector mounting structure in the Dewar when the detector is working at low temperature, thereby effectively solving the low-temperature thermal stress problem caused by the support column 1 and the low-temperature heat leakage problem of the support column 1.

[0035] Preferably, each support column 1 is provided with a cold shrink structure 2 .

[0036] 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 cold shrink support structure for Dewar packaging, comprising a support column (1) and a cold shrink structure (2), wherein the cold shrink structure (2) is arranged on the support column (1) with a gap; characterized in that: The support column (1) comprises a base (11), a heat-insulating column (12) and a mounting portion (13); The cold shrink structure (2) comprises a cold shrink frame (21) and a cold shrink rod (22), wherein the cold shrink rod (22) is arranged in the cold shrink frame (21), and the material expansion coefficient of the cold shrink frame (21) is greater than the material expansion coefficient of the cold shrink rod (22); The cold shrink structure (2) is arranged on the mounting portion (13), and there is a gap between the cold shrink structure (2) and the mounting portion (13).

2. The cold shrink support structure for Dewar packaging according to claim 1, characterized in that: The shrink structure (2) comprises two or more parallel-connected rhombus-shaped shrink frames (21), each of which has a shrink rod (22) fixedly disposed therein, and the shrink rod (22) is disposed between two apex angles corresponding to the long diagonal line of the rhombus.

3. The cold shrink support structure for Dewar packaging according to claim 2, characterized in that: The mounting portion (13) has a mounting seat wall (131); the shrink frame (21) is fixedly connected to the mounting seat wall (131) with a gap.

4. The cold shrink support structure for Dewar packaging according to claim 3, characterized in that: The mounting portion (13) is a rectangular parallelepiped surrounded by three mounting portion walls (131) with one end open, and each mounting seat wall (131) is provided with a screw hole; at room temperature, the screws pass through the screw holes and abut against the edge of the shrink frame (21), so that the bottom of the shrink structure (2) does not contact the mounting seat (13), and the shrink frame (21) is fixed in the mounting portion (13) with a gap.

5. The cold shrink support structure for Dewar packaging according to claim 4, characterized in that: The gap between the mounting seat wall (131) and the shrink frame (21) is 1 mm to 5 mm.

6. The cold shrink support structure for Dewar packaging according to claim 1, characterized in that: The shrink frame (21) of the shrink structure (2) is made of aluminum or copper with a high expansion coefficient; the shrink rod (22) is made of Kovar, Invar, titanium alloy or molybdenum with a low expansion coefficient.

7. The cold shrink support structure for Dewar packaging according to claim 1, characterized in that: The support column (1) is made of titanium alloy, stainless steel or glass fiber reinforced plastic with low thermal conductivity.

8. The cold shrink support structure for Dewar packaging according to claim 1, characterized in that: Each support column (1) is provided with a cold shrink structure (2).

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