Dewar support structure for a refrigerated infrared detector

Abstract

The present invention discloses a Dewar support structure for a refrigerated infrared detector, which includes a support ring fixedly connected between a cold finger and a housing. The support ring includes an outer ring fixedly connected to the inner wall of the housing, an inner ring fixedly connected to the outer wall of the cold finger, and an elastomer wound around multiple turns between the outer ring and the inner ring. The inner end of the elastomer is fixedly connected to the outer wall of the inner ring, and the outer end of the elastomer is fixedly connected to the inner wall of the outer ring. When the cold finger swings, the elastomer wound around multiple turns can absorb the impact energy of the cold finger swing, thereby reducing the swing amplitude of the cold finger. The present invention is a novel Dewar-spring support ring structure for resisting large-scale impact vibrations. By increasing the heat transfer path through the annular structure, the Dewar cold loss is reduced. At the same time, the energy of the impact is absorbed through elastic potential energy, increasing the mechanical reliability of the Dewar cold head cantilever beam structure during the impact vibration process.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigerated infrared detectors, and particularly to a Dewar support structure for a refrigerated infrared detector. Background Art

[0002] Infrared detectors are the core components of infrared technology and also the forerunners of the development of infrared technology. Infrared detectors have a very wide range of applications in civil and military fields such as missile guidance, space exploration, early warning satellites, and reconnaissance.

[0003] In a refrigerated infrared detector - Dewar, the cold finger cylinder is a cantilever beam structure. At the same time, since the substrate and cold shield of the infrared detector are assembled at the top of the cold finger cylinder, the cold finger cylinder becomes the weakest mechanical link in the entire infrared detector assembly.

[0004] In the prior art, a linear rigid contact support ring is used to reinforce the cantilever beam structure at the top of the cold finger. However, the heat conduction path of the linear support rod is relatively short, resulting in a large sacrifice of the cold loss of the Dewar, increasing the burden on the refrigerator. Due to the rigid characteristics of the support rod, the force on the cold shield filter at the cold head when impacted does not decrease significantly, and the risk of detachment is still very high. Summary of the Invention

[0005] To solve the problems existing in the prior art, the present invention provides a Dewar support structure for a refrigerated infrared detector, which is a novel Dewar - spring support ring structure that resists a large magnitude of impact and vibration. By increasing the heat transfer path through a ring structure, the cold loss of the Dewar is reduced. At the same time, the elastic potential energy is used to absorb the impact energy, increasing the mechanical reliability of the cold finger cantilever beam structure during the impact and vibration process.

[0006] The technical solution for the present invention to solve the problem is to provide a Dewar support structure for a refrigerated infrared detector, including a support ring fixedly connected between the cold finger and the outer shell. The support ring includes an outer ring fixedly connected to the inner wall of the outer shell, an inner ring fixedly connected to the outer wall of the cold finger, and an elastic body wound around multiple turns between the outer ring and the inner ring. The inner end of the elastic body is fixedly connected to the outer wall of the inner ring, and the outer end of the elastic body is fixedly connected to the inner wall of the outer ring. When the cold finger swings, the elastic body wound around multiple turns can absorb the impact energy of the cold finger swing, thereby reducing the swing amplitude of the cold finger.

[0007] Further, an elastic space is reserved between adjacent turns of the winding structure of the elastic body, so that the adjacent turns of the winding structure are distributed at intervals without external force.

[0008] Further, the cold finger is located inside the outer shell, the inner ring and the outer ring are on the same horizontal plane, and the elastic body is horizontally wound between the outer ring and the inner ring.

[0009] Further, a plurality of the support rings are arranged at intervals up and down between the cold finger and the outer shell.

[0010] Further, the inner ring and the outer ring are located at different horizontal planes, and the elastic body is wound between the outer ring and the inner ring in a manner of increasing height.

[0011] Further, the support rings are located at the upper part of the cold finger, and the top of the cold finger is used for installing a chip.

[0012] Further, the elastic body is a horizontally spiral structure with a central diffusion type. The inner end of the elastic body is smoothly butt - jointed and fixed with the outer wall of the inner ring, and the outer end of the elastic body is smoothly butt - jointed and fixed with the inner wall of the outer ring.

[0013] Further, the elastic body is composed of a plurality of annular elastic rings with increasing diameters and notches and a plurality of connecting parts. The plurality of elastic rings are arranged coaxially and the notch positions correspond. The plurality of connecting parts sequentially connect the diagonal ends of the inner elastic ring and the outer elastic ring, thereby connecting the plurality of elastic rings in series and fixing them to form the elastic body.

[0014] Further, the notch lengths of the plurality of elastic rings gradually increase from the inner ring to the outer ring, and the lengths of the plurality of connecting parts match the notch lengths.

[0015] Further, the free end of the innermost elastic ring of the elastic body is smoothly butt - jointed and fixed with the outer wall of the inner ring through the shortest connecting part.

[0016] Further, the free end of the outermost elastic ring of the elastic body is smoothly butt - jointed and fixed with the inner wall of the outer ring through the longest connecting part.

[0017] Preferably, the elastic body is composed of a plurality of annular elastic rings with equally increasing diameters and notches and a plurality of connecting parts with equally increasing lengths. The plurality of elastic rings are arranged coaxially and one end of the notch is aligned. The plurality of connecting parts sequentially connect the non - aligned end of the notch of the inner elastic ring and the aligned end of the notch of the outer elastic ring, thereby connecting the plurality of elastic rings in series and fixing them to form the elastic body.

[0018] The aligned end of the notch of the innermost elastic ring of the elastic body is smoothly butt - jointed and fixed with the outer wall of the inner ring through the shortest connecting part.

[0019] The non - aligned end of the notch of the outermost elastic ring of the elastic body is smoothly butt - jointed and fixed with the inner wall of the outer ring through the longest connecting part.

[0020] Further, the elastomer is made of an elastic material. The connecting portion and the elastic ring are both made of an elastic material.

[0021] Further, the length of the connecting portion is twice the distance between the elastic rings.

[0022] Further, the relative inclination angle of the connecting portion decreases as the diameter of the elastic ring increases, that is, the longer the length of the connecting portion, the smaller the relative inclination angle.

[0023] Further, first limiting members are provided on both the upper and lower sides of the horizontally arranged support ring. At least two of the first limiting members are respectively arranged on both sides of the cold finger. Both ends of the first limiting member are fixedly connected to the inner wall of the housing, and the first limiting member is arranged parallel to the support ring.

[0024] Further, the length of the first limiting member is less than the diameter of the outer ring and greater than the radius of the outer ring.

[0025] Further, second limiting members are provided on both the upper and lower sides of the horizontally arranged support ring. A plurality of the second limiting members are distributed around the cold finger as the center and fixedly connected to the inner wall of the housing. The second limiting member is arranged parallel to the support ring.

[0026] Further, the length of the second limiting member is less than the radius of the outer ring, and an arc-shaped concave surface is provided at the front end of the second limiting member facing the cold finger.

[0027] Further, a plurality of the second limiting members are provided on the lower side of the horizontally arranged support ring. A plurality of the second limiting members are distributed around the cold finger as the center and fixedly connected to the inner wall of the housing; at least two first limiting members are provided on the upper side of the horizontally arranged support ring and are respectively arranged on both sides of the cold finger.

[0028] The beneficial effects of the present invention are as follows:

[0029] The present invention is a Dewar support structure for a refrigerated infrared detector. A spring-type support ring structure is added to the head of the cold finger. At the same time, the inner ring of the support ring is bonded or welded to the cold finger. When the detector is working normally, the cold quantity will exchange heat with the outside through a longer heat transfer path. Compared with the traditional support ring structure, it will not excessively increase the cold loss of the Dewar and reduce the burden on the refrigerator.

[0030] When the detector assembly is affected by impact vibration of a relatively large magnitude, the cantilever beam structure of the cold finger will swing, and at the same time, the spring structure in the support ring will deform. The energy brought by the impact is converted into the elastic potential energy of the spring and absorbed. A spring with appropriate strength can absorb a large amount of impact energy, greatly reducing the swing of the cold head. This significantly reduces the forces on the cold shield, filter, chip, ceramic substrate, etc. on the cold head, reducing the risk of fragmentation and detachment. At the same time, the swing amplitude of the lead wire (usually made of platinum-iridium wire) between the ceramic substrate and the ceramic lead ring is reduced, the force on the lead wire is reduced, and the risk of lead wire breakage is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings incorporated herein and constituting a part of this specification illustrate embodiments of the present invention and, together with the description, are used to explain the principles of the present invention. In these drawings, like reference numerals are used to represent like elements. The drawings in the following description are some embodiments of the present invention, not all embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 Schematic installation diagram of the Dewar support structure of a refrigerated infrared detector according to an embodiment of the present invention;

[0033] Figure 2 Structural diagram of the support ring of the Dewar support structure of a refrigerated infrared detector according to an embodiment of the present invention;

[0034] Figure 3 Top view of the support structure of the Dewar support structure of a refrigerated infrared detector according to an embodiment of the present invention;

[0035] Figure 4 Distribution schematic diagram of the first limiting member of the Dewar support structure of a refrigerated infrared detector according to an embodiment of the present invention;

[0036] Figure 5 Distribution schematic diagram of the second limiting member of the Dewar support structure of a refrigerated infrared detector according to an embodiment of the present invention.

[0037] In the figures: 1, cold finger; 2, support ring; 3, outer shell; 4, substrate; 5, chip; 6, cold shield; 7, first limiting member; 8, second limiting member; 21, outer ring; 22, inner ring; 23, elastic ring; 24, connecting portion. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0039] To solve the above problems, the present invention proposes a Dewar support structure for a refrigerated infrared detector. Please refer to Figures 1 - 5 , which includes a support ring 2 fixedly connected between the cold finger 1 and the outer shell 3. The support ring 2 includes an outer ring 21 fixedly connected to the inner wall of the outer shell 3, an inner ring 22 fixedly connected to the outer wall of the cold finger 1, and an elastomer wound around multiple turns between the outer ring 21 and the inner ring 22. The inner end of the elastomer is fixedly connected to the outer wall of the inner ring 22, and the outer end of the elastomer is fixedly connected to the inner wall of the outer ring 21. When the cold finger 1 swings, the elastomer wound around multiple turns can absorb the impact energy of the swing of the cold finger 1, thereby reducing the swing amplitude of the cold finger 1.

[0040] In a specific embodiment, a horizontal circumferential support structure, i.e., the support ring 2, is added to the head of the cold finger 1. The inner ring 22 of the support ring 2 is bonded or welded to the outer wall of the cold finger 1, and the outer ring 21 is bonded or welded to the inner wall of the outer shell 3. The inner ring 22 and the outer ring 21 are in the same horizontal plane, and the elastomer is horizontally wound between the inner ring 22 and the outer ring 21. When the detector is working normally, the cold quantity will exchange heat with the outside through a longer heat transfer path. Compared with the traditional support structure, the technical solution of the present invention will not excessively increase the cold loss of the Dewar and reduces the burden on the refrigerator.

[0041] In another specific embodiment, the inner ring 22 and the outer ring 21 may also be in different horizontal planes (not shown in the drawings). Specifically, the inner ring 22 is located in the upper part and the outer ring 21 is located in the lower part. Then, the elastomer is wound between the outer ring 21 and the inner ring 22 in a manner of increasing height, and the effect of reducing the swing amplitude of the cold finger 1 and not excessively increasing the cold loss of the Dewar can also be achieved.

[0042] The embodiments of the present invention will be described by taking the case where the inner ring 22 and the outer ring 21 are in the same horizontal plane as an example.

[0043] When the detector assembly is affected by shock and vibration of a relatively large magnitude, the cantilever beam structure of the cold finger 1 will swing. At the same time, the elastomer in the support ring 2 deforms, and the energy brought by the shock is converted into the elastic potential energy of the elastomer and absorbed. An appropriate intensity of elastic deformation can absorb a large amount of shock energy, greatly reducing the swinging phenomenon of the upper part of the cold finger 1. The forces on the cold shield 6, filter, chip 5, substrate 4, etc. installed at the top of the cold finger 1 are greatly reduced, and the risks of fragmentation and detachment are reduced. At the same time, the swing amplitude of the lead (usually made of platinum-iridium wire) between the substrate 4 and the lead ring is small, the force on the lead is reduced, and the risk of lead breakage is reduced.

[0044] It should be clear that the cold finger 1 is located inside the housing 3 and can be located at the central position. The support ring 2 is horizontally placed between the cold finger 1 and the housing 3. The fixed position of the support ring 2 can be at the upper part of the cold finger 1, close to the top. Multiple support rings 2 can be provided between the cold finger 1 and the housing 3 according to the actual length of the cold finger 1 or the actual impact resistance requirements.

[0045] In order to achieve the elastic deformation of the elastomer, an elastic space should be reserved between adjacent winding structures of the elastomer wound horizontally in multiple turns for the winding structures to undergo elastic deformation. When no external force acts, the adjacent winding structures are all spaced apart and do not come into contact. The same is true for between the outer ring 21 and the inner ring 22.

[0046] In the embodiment of the present invention, the elastomer is made of an elastic material and should have a certain rigidity, such as superalloy spring steel, grade GH4169.

[0047] As an implementation manner, the winding method of the elastomer can be center diffusion type, forming a horizontal spiral structure between the outer ring 21 and the inner ring 22. The inner end of the spiral structure is smoothly butt-jointed and fixed to the outer wall of the inner ring 22, and the outer end is smoothly butt-jointed and fixed to the inner wall of the outer ring 21. The spacing between each turn of the spiral structure can be the same.

[0048] As another implementation manner, please refer to Figure 2 、 Figure 3 , the elastomer is composed of a plurality of annular elastic rings 23 with notches whose diameters increase from the inner ring 22 to the outer ring 21 and a plurality of connecting parts 24. The plurality of elastic rings 23 are arranged coaxially and the notch positions correspond. The plurality of connecting parts 24 sequentially connect the diagonal ends of the inner elastic ring 23 and the outer elastic ring 23 in sequence, thereby connecting the plurality of elastic rings 23 in series and fixing them to form the elastomer.

[0049] Preferably, the notch lengths of the plurality of elastic rings 23 gradually increase from the inner ring 22 to the outer ring 21, and the lengths of the plurality of connecting parts 24 can be correspondingly matched with the notch lengths.

[0050] The free end of the innermost elastic ring 23 of the elastomer is smoothly butt - jointed and fixed to the outer wall of the inner ring 22 through the shortest connecting part 24.

[0051] The free end of the outermost elastic ring 23 of the elastomer is smoothly butt - jointed and fixed to the inner wall of the outer ring 21 through the longest connecting part 24.

[0052] Specifically, the elastomer can be composed of a plurality of annular elastic rings 23 with notches whose diameters increase equally, and a plurality of connecting parts 24 whose lengths increase equally. It can be understood that the increment of the length of the connecting part 24 is positively correlated with the increment of the diameter of the elastic ring 23.

[0053] A plurality of elastic rings 23 can be arranged coaxially, and with one end of the notch aligned as a standard, both ends of the plurality of connecting parts 24 are sequentially connected to the non - aligned end of the notch of the inner - side elastic ring 23 and the aligned end of the notch of the outer - side elastic ring 23, so as to sequentially connect and fix a plurality of elastic rings 23 to form an elastomer.

[0054] When fixedly connecting the elastomer with the outer ring 21 and the inner ring 22, the connecting part 24 can also be used for smooth butt - joint fixation. Specifically, the aligned end (free end) of the notch of the innermost elastic ring 23 of the elastomer can be smoothly butt - jointed and fixed to the outer wall of the inner ring 22 through the shortest connecting part 24; the non - aligned end (free end) of the notch of the outermost elastic ring 23 of the elastomer can be smoothly butt - jointed and fixed to the inner wall of the outer ring 21 through the longest connecting part 24.

[0055] It can be understood that both the elastic ring 23 and the connecting part 24 are made of elastic materials.

[0056] Preferably, the length of the connecting part 24 is twice the distance between the elastic rings 23, so as to reduce the inclination angle of the connecting part 24 and make the overall elastic effect of the elastomer better. It can be understood that the relative inclination angle of the connecting part 24 decreases as the diameter of the elastic ring 23 increases, that is, the longer the length of the connecting part 24, the smaller the relative inclination angle.

[0057] In the embodiment of the present invention, please refer to Figure 4 , on both the upper and lower sides of the horizontally arranged support ring 2, first limit members 7 are provided. At least two first limit members 7 are arranged on both sides of the cold finger 1. Both ends of the first limit member 7 are fixedly connected to the inner wall of the housing 3. The first limit member 7 is arranged parallel to the support ring 2. The first limit member 7 can be made of an elastic material and is located on both the upper and lower sides of the support ring 2. When the support ring 2 undergoes a large non - horizontal deformation, it restricts the damaging deformation of the elastomer in the support ring 2 and effectively avoids structural damage.

[0058] Specifically, the length of the first limiting member 7 is less than the diameter of the outer ring 21 and greater than the radius of the outer ring 21, and it can press most of the wound ring structures.

[0059] In an embodiment of the present invention, please refer to Figure 5 , another feasible solution is also proposed for the non-horizontal deformation of the support ring 2: Second limiting members 8 can be provided on both the upper and lower sides of the horizontally arranged support ring 2. A plurality of second limiting members 8 are distributed around the cold finger 1 as the center and fixedly connected to the inner wall of the outer shell 3. The second limiting members 8 are arranged in parallel with the support ring 2.

[0060] Specifically, the length of the second limiting member 8 is less than the radius of the outer ring 21. An arc-shaped concave surface is provided at the front end of the second limiting member 8 facing the cold finger 1. A plurality of second limiting members 8 cooperate with each other to stably press the non-horizontal deformation in all directions of the wound ring structure.

[0061] Based on the above two limiting forms, a third feasible solution can be formed by mutual cooperation: A plurality of second limiting members 8 are provided on the lower side of the horizontally arranged support ring 2. A plurality of second limiting members 8 are distributed around the cold finger 1 as the center and fixedly connected to the inner wall of the outer shell 3; At least two first limiting members 7 are provided on the upper side of the horizontally arranged support ring 2 and are arranged on both sides of the cold finger 1. It is also possible to reverse the use of the first limiting member 7 and the second limiting member 8.

[0062] The content described above can be implemented alone or in various combinations, and these variant ways are all within the protection scope of the present invention.

[0063] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the element.

[0064] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific embodiments of the present invention are only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. Dewar support structure for a refrigerated infrared detector, Characterized in that, It includes a support ring (2) fixedly connected between the cold finger (1) and the outer shell (3). The support ring (2) includes an outer ring (21) fixedly connected to the inner wall of the outer shell (3), an inner ring (22) fixedly connected to the outer wall of the cold finger (1), and an elastic body wound around multiple turns between the outer ring (21) and the inner ring (22). The inner end of the elastic body is fixedly connected to the outer wall of the inner ring (22), and the outer end of the elastic body is fixedly connected to the inner wall of the outer ring (21).

2. The Dewar support structure for a refrigerated infrared detector according to claim 1, Characterized in that, An elastic space is reserved between adjacent two-turn winding structures of the elastic body, so that the adjacent two-turn winding structures are spaced apart when not under external force.

3. The Dewar support structure for a refrigerated infrared detector according to claim 1, Characterized in that, The cold finger (1) is located inside the outer shell (3). The inner ring (22) and the outer ring (21) are on the same horizontal plane, and the elastic body is horizontally wound between the outer ring (21) and the inner ring (22).

4. The Dewar support structure for a refrigerated infrared detector according to claim 3, Characterized in that, A plurality of the support rings (2) are arranged at intervals up and down between the cold finger (1) and the outer shell (3).

5. The Dewar support structure for a refrigerated infrared detector according to claim 1, Characterized in that, The inner ring (22) and the outer ring (21) are on different horizontal planes, and the elastic body is wound between the outer ring (21) and the inner ring (22) in a manner of increasing height.

6. The Dewar support structure for a refrigerated infrared detector according to claim 1, Characterized in that, The support ring (2) is located above the cold finger (1), and the top of the cold finger (1) is used to install the chip (5).

7. The Dewar support structure for a refrigerated infrared detector according to claim 1, Characterized in that, The elastic body is a horizontally spiral structure with a central diffusion type. The inner side end of the elastic body is smoothly butt-jointed and fixed to the outer wall of the inner ring (22), and the outer side end of the elastic body is smoothly butt-jointed and fixed to the inner wall of the outer ring (21).

8. The Dewar support structure for a refrigerated infrared detector according to claim 1, Characterized in that, The elastic body is composed of a plurality of elastic rings (23) in the shape of rings with increasing diameters and having notches, and a plurality of connecting parts (24). The plurality of elastic rings (23) are arranged coaxially and the notch positions correspond. The plurality of connecting parts (24) sequentially connect the diagonal ends of the inner elastic ring (23) and the outer elastic ring (23) in sequence, thereby connecting the plurality of elastic rings (23) in series and fixedly forming the elastic body.

9. The Dewar support structure for a refrigerated infrared detector according to claim 8, Characterized in that, The notch lengths of the multiple elastic rings (23) gradually increase in the direction from the inner ring (22) to the outer ring (21), and the lengths of the multiple connecting parts (24) match the notch lengths; the free end of the innermost elastic ring (23) of the elastic body is smoothly butt-jointed and fixed to the outer wall of the inner ring (22) through the shortest connecting part (24); the free end of the outermost elastic ring (23) of the elastic body is smoothly butt-jointed and fixed to the inner wall of the outer ring (21) through the longest connecting part (24).

10. The Dewar support structure of a refrigerated infrared detector according to claim 1, wherein, the elastic body is made of an elastic material.

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