Exhaust slots, cold shields, cold shield components, cold head parts, Dewar and infrared detectors

Abstract

The present invention relates to an exhaust groove, comprising a groove body, wherein the groove body has an exhaust channel for high-temperature gas to be discharged, and a blocking structure for blocking excess matter is provided in the exhaust channel, wherein the blocking structure comprises a plurality of protrusions provided on the groove wall, and along the direction of high-temperature gas discharge in the exhaust channel, the angle between the edge of each protrusion close to the outlet side of the exhaust channel and the groove wall is greater than 0° and less than or equal to 90°. A cold shield is also provided, comprising a body and the above-mentioned exhaust groove. A cold shield assembly is also provided. A cold head component is also provided. A dewar is also provided. An infrared detector is also provided. The present invention can block excess matter from the outside by providing protrusions in the groove body and controlling the angle between the protrusions and the groove wall to prevent the excess matter from entering the cold shield, and when excess matter accumulates in the exhaust channel to saturation, the exhaust channel will automatically close, and subsequent excess matter will be blocked outside, thereby greatly reducing the probability of excess matter appearing inside the cold shield.

Description

Technical Field

[0001] The invention relates to the technical field of detectors, in particular to an exhaust slot, a cold shield, a cold shield assembly, a cold head component, a dewar and an infrared detector. Background Art

[0002] The detector chip is packaged in a vacuum dewar, and the cold shield assembly is placed in front of the focal plane detector chip to limit stray light. To ensure the high vacuum of the dewar, exhaust holes are designed on the cold shield to facilitate exhausting the air inside the cold shield during high-temperature exhaust. However, during the actual use of the detector, excess matter outside the cold shield in the dewar will enter the cold shield through the exhaust holes and appear in the infrared imaging light path, causing abnormal images.

[0003] In addition, infrared focal plane detectors are widely used in various fields such as national defense security and environmental monitoring due to their high sensitivity, good environmental adaptability, and strong anti-interference ability. With the continuous improvement of user needs, the requirements for infrared detectors to resist overload shock are also more stringent.

[0004] At present, in order to improve the impact resistance of infrared focal plane detectors, the main approach is to increase the strength of the cold finger components of the Dewar cantilever beam structure. Specifically, the thickness of the cold finger cylinder wall is increased, a reinforcing rib structure is designed at the root of the cold finger cylinder, and a support rod is designed at the cold head end of the Dewar.

[0005] For infrared imaging equipment, during the launch process, the equipment will generate a large acceleration, causing the components in the equipment to withstand a short-term high overload of up to tens of thousands of g at the moment of launch. The existing technology for improving the impact strength of infrared detectors cannot meet the high overload requirements. At the same time, after the strength is improved according to the existing technology, the wall thickness of the Dewar cold finger is thickened, and the cold loss of the cold head increases, resulting in a longer startup time for the refrigerated infrared detector, which seriously affects the combat capability. Summary of the invention

[0006] The object of the present invention is to provide an exhaust slot, a cold shield, a cold shield assembly, a cold head component, a dewar and an infrared detector, which can at least solve some of the defects in the prior art.

[0007] To achieve the above-mentioned objectives, an embodiment of the present invention provides the following technical solutions: an exhaust groove, comprising a groove body, wherein the groove body has an exhaust channel for high-temperature gas to be discharged, and the exhaust channel is provided with a blocking structure for blocking excess materials, and the blocking structure includes a plurality of protrusions arranged on the groove wall of the groove body, and along the direction of discharge of high-temperature gas in the exhaust channel, the angle between the edge of each protrusion close to the outlet side of the exhaust channel and the groove wall is greater than 0° and less than or equal to 90°.

[0008] Furthermore, the protrusion is in a triangular structure, and one side of the triangular structure fits the groove wall.

[0009] Furthermore, the tank body has multiple sections of bent exhaust passages.

[0010] Furthermore, the tank body is U-shaped.

[0011] An embodiment of the present invention provides another technical solution: a cold shield, comprising a main body and the above-mentioned exhaust groove, wherein the exhaust groove is embedded on the end surface of the main body.

[0012] Furthermore, a middle portion of the end surface is provided with an exhaust port, and the exhaust groove is communicated with the exhaust port.

[0013] An embodiment of the present invention provides another technical solution: a cold screen assembly, including a filter, and also the above-mentioned cold screen, the filter covers the end surface, and the filter blocks most of the exhaust grooves, and the exhaust grooves not blocked by the filter are exhaust holes.

[0014] The embodiment of the present invention provides another technical solution: a cold head component, including the above-mentioned cold shield.

[0015] The embodiment of the present invention provides another technical solution: a Dewar, comprising the above-mentioned cold head component.

[0016] The embodiment of the present invention provides another technical solution: an infrared detector, comprising the above-mentioned Dewar.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. By setting a protrusion in the groove body and controlling the angle between the protrusion and the groove wall, the excess matter from the outside can be blocked to prevent it from entering the cold screen. When the excess matter accumulates too much in the exhaust channel to saturation, the exhaust channel will automatically close and the subsequent excess matter will be blocked outside, thereby greatly reducing the probability of excess matter appearing inside the cold screen.

[0019] 2. A support structure is installed on the cold finger cylinder to support and reinforce the weak neck of the cold finger, thereby improving the support strength and resisting higher impact strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a cold shield assembly provided by an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a cold shield provided by an embodiment of the present invention;

[0022] Figure 3 A vertical cross-sectional schematic diagram of an infrared detector provided by an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of a signal extraction component of an infrared detector provided by an embodiment of the present invention;

[0024] In the accompanying drawings: 1-filter; 2-Dewar; 21-main body; 22-cold head; 220-cold shield; 2200-exhaust port; 2201-exhaust groove; 2202-exhaust channel; 2203-protrusion; 2204-exhaust hole; 2205-end face; 221-ceramic strip; 222-chip; 24-cold finger; 240-cold finger cylinder; 241-cold plate; 242-support ring; 25-window component; 250-infrared window; 251-window frame; 252-pressing ring; 26-signal lead-out part; 260-metal ring; 261-connector. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0026] See also Figure 2, an embodiment of the present invention provides an exhaust slot, including a slot body, wherein the slot body has an exhaust channel 2202 for high-temperature gas to be discharged, and the exhaust channel 2202 is provided with a blocking structure for blocking excess matter, and the blocking structure includes a plurality of protrusions 2203 provided on the slot wall, and along the direction of high-temperature gas discharge in the exhaust channel 2202, the angle between the edge of each protrusion 2203 close to the outlet side of the exhaust channel 2202 and the slot wall is not greater than 90°. In this embodiment, by providing the protrusion 2203 in the slot body and controlling the angle between the protrusion 2203 and the slot wall, the excess matter from the outside can be blocked to prevent it from entering the cold shield 220, and when the excess matter accumulates too much in the exhaust channel 2202 to saturation, the exhaust channel 2202 will automatically close, and the subsequent excess matter will be blocked outside, thereby greatly reducing the probability of excess matter appearing inside the cold shield 220. Specifically, the exhaust slot 2201 can be used on the cold shield 220 to exhaust and block excess matter. After the infrared detector is assembled, the high-temperature gas needs to be discharged from the exhaust hole 2204. This process is one-time, and the high-temperature gas will not be discharged again after being discharged. At this time, the exhaust hole 2204 is useless. However, the exhaust hole 2204 is still retained, so that the external excess material will enter the cold shield 220 from the exhaust hole 2204, and then an abnormality will occur. The exhaust groove 2201 described in this embodiment is used on the cold shield 220. Initially, the exhaust groove 2201 can be used as an exhaust channel 2202 for exhaust. After the excess material enters the exhaust channel 2202, the excess material can be blocked in the exhaust channel 2202 under the action of its blocking structure. After the excess material is gradually deposited, the exhaust channel 2202 will be completely blocked, so that the excess material from the outside will no longer be able to enter the cold shield 220. Specifically, the blocking method can be a protrusion 2203, which extends toward the exhaust channel 2202. In the direction of high-temperature gas discharge along the exhaust channel 2202, the high-temperature gas inlet of the exhaust channel 2202 can be defined as the inlet side, and the high-temperature channel outlet can be defined as the outlet side, and the outlet side is the side of the exhaust hole 2204. We limit the angle between the edge of the protrusion 2203 close to the outlet side and the groove wall to no more than 90°, that is, the protrusion 2203 can be at most 90°, that is, it is set perpendicular to the groove wall, or it can be an acute angle, which can ensure that the excess is blocked by the protrusion 2203 in the exhaust channel 2202. Here, it can be simply understood that the direction in which the protrusion 2203 extends is the opposite direction to the direction in which the excess enters (when the angle is an acute angle), and the reverse direction can well complete the blocking of the excess. Preferably, the blocking structure can of course not only include the protrusion 2203 arranged on the groove wall, but also a blocking object arranged on the groove bottom.As for the protrusion 2203 and the extending length of the barrier, they can be selected according to the actual situation to ensure that the discharge of high-temperature gas will not be blocked while completely blocking excess matter. In fact, as long as there is a slight gap, it will not affect the discharge of gas, so it is easy to achieve complete blocking of excess matter.

[0027] As an optimization solution of the embodiment of the present invention, please refer to Figure 2 , the protrusion 2203 is in a triangular structure, and one side of the triangular structure is in contact with the groove wall. In this embodiment, the protrusion 2203 can be refined into a triangular structure, and the barbs formed by the triangular structure can well block excess matter. Of course, in addition to the triangular structure, structures such as rectangular and irregular shapes are also feasible. As long as the structural form can block excess matter, it is a feasible structure, and this embodiment does not limit this.

[0028] As an optimization solution of the embodiment of the present invention, please refer to Figure 2 , the trough body has a plurality of bent exhaust passages 2202. In this embodiment, the trough body may not only be a conventional shape, such as a square trough, but may also be a trough with a plurality of bent exhaust passages 2202, so that a maze-like form can be formed, which is conducive to the blocking of excess objects. Preferably, for example, it is a U-shape, and of course other irregular shapes are possible, and this embodiment does not limit this.

[0029] See also Figure 2 , an embodiment of the present invention provides a cold shield, comprising a body and the above-mentioned exhaust groove 2201, wherein the exhaust groove 2201 is embedded in the end face 2205 of the body. In this embodiment, the above-mentioned exhaust groove 2201 is embedded in the end face 2205 of the body, or the exhaust groove 2201 can be directly opened on the end face 2205. In this way, the exhaust groove 2201 can be cleverly applied to the cold shield 220 to achieve the functions of exhausting and blocking excess. Preferably, the middle part of the end face 2205 has an exhaust port 2200, and the exhaust groove 2201 is connected to the exhaust port 2200, and the high-temperature gas is discharged from here and enters the exhaust groove 2201.

[0030] As an optimization solution of the embodiment of the present invention, please refer to Figure 1 and Figure 2, an embodiment of the present invention provides a cold shield assembly, including a filter 1 and the above-mentioned cold shield 220, wherein the filter 1 covers the end face 2205, and the filter 1 blocks most of the exhaust slots 2201, and the exhaust slots 2201 not blocked by the filter 1 are exhaust holes 2204. In this embodiment, in an infrared detector in which the cold shield 220 is used in conjunction with the filter 1, the filter 1 can be covered on the end face 2205 of the cold shield 220. The cold shield 220 is preferably a split-type welding structure, and the above-mentioned exhaust slots 2201 are designed on its first step (i.e., the top layer), and then the filter 1 is covered on the first step (i.e., the end face 2205). At this time, the size of the filter 1 can be designed so that it does not completely cover and block the exhaust slots 2201, so that the exhaust holes 2204 can exist in the unblocked parts of the exhaust slots 2201, such as Figure 1 As shown, the exhaust hole 2204 is very small, so the filter 1 covers most of the exhaust slot 2201. Since the exhaust slot 2201 is embedded in the end face 2205 of the cold shield 220, or is directly made on the end face 2205, so that the upper surface of the exhaust slot 2201 is flush with the end face 2205, then after the filter 1 covers the end face 2205, it can cover the end face 2205 without a gap, and the high-temperature gas can only be discharged from the exhaust channel 2202 of the exhaust slot 2201. Preferably, a solution with multiple exhaust slots 2201 can be optimized here. When the exhaust speed needs to be accelerated, more exhaust slots 2201 can be set on the end face 2205, and then multiple exhaust holes 2204 are formed for exhaust, thereby improving the exhaust efficiency.

[0031] As an optimization solution of the embodiment of the present invention, the embodiment of the present invention provides a cold head component, which can use the above-mentioned cold shield 220. It can also be a cold head component 22 without using the filter 1 to reduce the mass of the cold head component 22, which will be described in detail in the following embodiments.

[0032] As an optimization solution of the embodiment of the present invention, the embodiment of the present invention provides a dewar, which can adopt the above-mentioned cold head component 22. Of course, the dewar 2 also includes a cold finger component 24, a window component 25, a signal lead-out part 26 and a main body component 21 and other structures.

[0033] Specifically, see Figure 2 and Figure 3 For the cold head component 22, it mainly includes a cold shield 220 and a ceramic strip 221 for exporting the signal of the chip 222. There are still two solutions, one is to use the cold shield 220 of the filter 1, and the other is to not use the cold shield 220 of the filter 1. When the filter 1 is used, as Figure 2 As shown, the cold shield 220 with the exhaust slot 2201 mentioned above can be used. When the filter 1 is not used, as shown in FIG. Figure 3As shown, the cold shield 220 adopts a lightweight material integrated molding design, and the filtering function is integrated into the window component 25, thereby eliminating the conventional filter 1 design and reducing the mass of the cold head component 22. In addition, a ceramic strip 221 is used to replace the traditional ceramic substrate structure, and then the signal is led out by wire bonding. In this way, through the strip structure, the electrical signal of the detector chip can be led out, and the mass of the cold head can be reduced. The cold head component 22.

[0034] For the cold finger component 24, see Figure 3 and Figure 4 , the cold finger component 24 is installed in the main body component 21, and the cold finger component 24 includes a cold finger cylinder 240 and a cold plate 241 welded above the cold finger cylinder 240, and a support structure is sleeved on the part of the cold finger cylinder 240 close to the cold plate 241, and the support structure is fixed on the main body component 21. In this embodiment, the support structure is sleeved on the cold finger cylinder 240, and the weak neck of the cold finger can be supported and reinforced, thereby improving the support strength, and then resisting higher impact strength. Specifically, the cold finger cylinder 240 adopts a conical structure, and the thinner part belongs to the weak neck. We design a support structure here to reinforce the support, which can improve the strength. Preferably, the support structure includes a support ring 242, the inner edge of the support ring 242 is close to the part of the cold finger cylinder 240 close to the cold plate 241, and the outer edge of the support ring 242 is fixed on the main body component 21. The support can be provided by a support ring 242. This structure is convenient for connecting the cold finger cylinder 240 and the main body 21, and the support ring 242 can be easily modified, such as providing a support rod between the inner edge and the outer edge of the support ring 242. The support rod acts as a reinforcing rib, which can not only improve the strength of the support ring 242 but also avoid the defects caused by the excessive weight of the solid support ring 242. Furthermore, there can be multiple support rods, preferably four, and the four support rods are evenly distributed in the space between the inner edge and the outer edge, and the cross-sectional area of ​​each support rod is controlled to be 0.075 to 0.115 mm. 2 This value range is the data obtained through a large number of experiments. The cross-sectional area design can improve the support strength while ensuring low heat leakage, so that the support ring 242 can effectively reduce the end shaking of the cold finger component 24 under the impact of lateral normal overload. Preferably, the cross-sectional area of ​​each support rod is 0.095mm 2 Better results can be obtained.

[0035] For further details of the above-mentioned cold finger component 24, please refer to Figure 3The cold finger cylinder 240 is a variable diameter cylinder, and the wall thickness of the variable diameter cylinder near the cold plate is between 0.7 and 0.9 mm, and the wall thickness near the root of the cold finger is between 0.4 and 0.5 mm, and the wall thickness of the variable diameter cylinder gradually decreases from the cold plate to the root of the cold finger. The cold finger cylinder 240 adopts a variable diameter design, and the wall thickness is designed under the condition of accurate calculation of the heat leakage of the cold finger. This value range is obtained through a large number of experiments, which can not only ensure the strength of the cold finger cylinder 240, but also avoid local excessive thickness and resulting in cold damage. Preferably, the wall thickness near the cold plate is 0.8 mm, and the wall thickness near the root of the cold finger is 0.45 mm to obtain better results.

[0036] As for the window component 25, it can be covered on the cold head component 22. The window component 25 includes an infrared window 250 and a window frame 251 for placing the infrared window 250. The width of the part of the window frame 251 where the infrared window 250 overlaps is controlled between 0.34 and 0.38 mm. In this embodiment, the infrared window 250 is a brittle material and is a weak point. The thickness of the infrared window 250 can be increased while ensuring the transmittance, and the overlapping area of ​​the window frame 251 and the infrared window 250 can be increased to reduce the area of ​​the middle suspended part, specifically between 0.34 and 0.38 mm. In this way, it can be ensured that there is a more stable support without blocking light. Preferably, a pressing ring 252 is provided above the infrared window 250, and the edge of the pressing ring 252 is provided on the window frame 251. A pressure ring 252 may be designed on the top of the infrared window 250 and then protected with glue. Preferably, the pressure ring 252 is a metal ring, which can play a reinforcing role and solve the stress problem here. Preferably, the width is 0.36 mm for better effect.

[0037] For the signal lead-out portion 26, please refer to Figure 3 and Figure 4 The signal lead-out part 26 includes a metal ring 260 disposed on the main body part 21, and a connector 261 for leading out the electrical signal is disposed outside the metal ring 260. In this embodiment, the connector 261 can be welded to the metal ring 260, and the connector 261 can also be made of ceramic. Compared with the ceramic lead ring in the traditional technology, the metal ring 260 can effectively improve the effect of resisting overload impact force. The traditional ceramic lead ring is easily broken and causes the detector to malfunction. The electrical signal can also be led out through the connector 261 without affecting the electrical signal lead-out.

[0038] As an optimization solution of the embodiment of the present invention, the embodiment of the present invention provides an infrared detector, which can adopt the above-mentioned Dewar 2. On the one hand, if the cold shield 220 in the above-mentioned embodiment is adopted, the problem of redundant objects can be solved. On the other hand, the strength design structure of the above-mentioned Dewar 2 can make it suitable for infrared image-guided artillery shells, and can resist the short-term high overload impact of up to tens of thousands of g that the artillery shells bear at the moment of launch. Of course, the infrared detector also includes conventional components such as a refrigerator, which will not be described in detail here.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cold screen, characterized in that: The invention comprises a main body and an exhaust groove, wherein the exhaust groove is embedded in the end surface of the main body, the exhaust groove comprises a groove body, the groove body has an exhaust channel for high-temperature gas to be discharged, the exhaust channel is provided with a blocking structure for blocking excess materials, the blocking structure comprises a plurality of protrusions arranged on the groove wall of the groove body, along the direction of high-temperature gas discharge in the exhaust channel, the angle between the edge of each protrusion close to the outlet side of the exhaust channel and the groove wall is greater than 0° and less than or equal to 90°.

2. The cold shield according to claim 1, characterized in that: The protrusion is in a triangular structure, and one side of the triangular structure is in contact with the groove wall.

3. The cold shield according to claim 1, characterized in that: The tank body has a plurality of bent exhaust passages.

4. The cold shield according to claim 1, characterized in that: The trough body is U-shaped.

5. The cold shield according to claim 1, characterized in that: An exhaust port is provided in the middle of the end surface, and the exhaust groove is communicated with the exhaust port.

6. A cold shield assembly, comprising a filter, characterized in that: It also includes the cold shield as described in any one of claims 1 to 5, wherein the filter covers the end surface, and the filter blocks most of the exhaust grooves, and the exhaust grooves not blocked by the filter are exhaust holes.

7. A cold head component, characterized in that: Comprising a cold shield as described in any one of claims 1-5.

8. A Dewar, characterized in that: Comprising the cold head component as claimed in claim 7.

9. An infrared detector, characterized in that: Comprising the Dewar of claim 8.

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