Leakage detection system and leakage detection method of infrared detector Dewar assembly

Abstract

The invention relates to the technical field of infrared detectors, and particularly provides a leak detection system and a leak detection method of an infrared detector Dewar assembly. The leak detection system comprises a leak detection tool, a leak detector and an air source. The leak detection tool is arranged to be a detachable closed box body, a plurality of leak detection stations are arranged in the leak detection tool, a to-be-detected Dewar assembly is fixed to each leak detection station in a sealed mode, and the to-be-detected Dewar assemblies are communicated with an air exhaust cavity in the leak detection tool when fixed to the leak detection stations. The leak detector is in sealing connection with the leak detection tool and is communicated with the interior of the air exhaust cavity. The gas source is connected with the leak detection tool in a sealing manner, is communicated with the area outside the air exhaust cavity in the leak detection tool, and is used for releasing the tracer gas. According to the leak detection system and the leak detection method provided by the invention, batch leak detection can be carried out on the Dewar assemblies, and batch production of the Dewar assemblies is adapted. The accuracy is higher, and the influence of tracer gas in an open leak detection environment is avoided. The automation degree is higher, and misjudgment of manual operation is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of infrared detectors, and in particular to a leak detection system and a leak detection method for a dewar assembly of an infrared detector. Background Art

[0002] The Dewar assembly is a key component of the refrigerated infrared detector, providing a vacuum insulation environment for the infrared detector. Encapsulating the infrared detector chip in a high vacuum Dewar flask can prevent external heat from affecting the low-temperature working environment of the infrared detector, thereby enabling the detector to work stably and accurately. Therefore, the Dewar flask needs to meet higher leakage rate grade requirements.

[0003] Dewar flasks are mostly made by welding, bonding and other methods, and the integrated Dewar components also need to meet the leakage rate level requirements. At present, helium mass spectrometers are used to detect leaks in Dewar components, but only small batches of Dewar components can be tested one by one, which is inefficient. At the same time, when leak detection is currently carried out in an open environment, helium residue can easily lead to misjudgment of the operation, affecting the accuracy of the leak detection results. Summary of the invention

[0004] The embodiments of the present invention provide a leak detection system and a leak detection method for a dewar assembly of an infrared detector, which at least solve the problems of low detection efficiency of the dewar assembly and easy misjudgment in an open environment.

[0005] In a first aspect, the present invention provides a leak detection system for an infrared detector dewar assembly, which includes: a leak detection tool, a leak detector, and a gas source; The leak detection tool is configured as a detachable closed box, and the leak detection tool comprises a plurality of leak detection stations, each of which is sealed and fixed with a dewar assembly to be tested, and the dewar assembly to be tested is connected to the air extraction chamber in the leak detection tool when fixed to the leak detection station; The leak detector is sealed and connected to the leak detection tooling, and is communicated with the interior of the air extraction cavity; The gas source is sealed and connected to the leak detection tool, and is communicated with the area outside the air extraction cavity in the leak detection tool, and the gas source is used to release the tracer gas.

[0006] The invention provides a leak detection system for an infrared detector dewar assembly, wherein the leak detection tool further comprises a base and a sealing cover, and the leak detection system further comprises a lifting module; The execution end of the lifting module is connected to the sealing cover, and the lifting module is used to control the sealing cover to rise or fall; when the sealing cover falls, it abuts against the base to make the closed box airtight.

[0007] The leak detection system of the infrared detector Dewar assembly provided by the embodiment of the invention also includes a control module; The control module is connected to the leak detector, and the control module controls the leak detector to evacuate air and reads the leak detection data of the leak detector; The control module is connected to the gas source, and the control module controls the gas source to release the tracer gas; The control module is connected to the lifting control module, and controls the lifting of the sealing cover through the lifting control module.

[0008] In the leak detection system of the infrared detector dewar assembly provided by the embodiment of the invention, each leak detection station is provided with a switch valve, and the switch valve is used to independently control the on-off between the dewar assembly to be tested and the air pumping chamber; The switch valve is configured to be manually controlled, or the switch valve is configured to be controlled by the control module.

[0009] The leak detection system of the infrared detector dewar assembly provided by the embodiment of the invention also includes an exhaust module; The exhaust module includes a fan, an exhaust duct and an exhaust control valve arranged on the exhaust duct; one end of the exhaust duct is connected to the area outside the vacuum chamber in the leak detection tooling, and the other end of the exhaust duct is connected to the fan; the exhaust control valve is used to control the on and off of the exhaust duct.

[0010] The invention provides a leak detection system for an infrared detector Dewar assembly, wherein the gas source comprises an airflow pipeline and a gas control valve arranged on the airflow pipeline; the airflow pipeline is connected to the area outside the vacuum cavity in the leak detection tooling.

[0011] In the leak detection system of the infrared detector Dewar assembly provided by the embodiment of the present invention, the gas control valve is configured as a gas flow control valve, or the gas control valve is configured as a gas pressure control valve.

[0012] In a second aspect, the invention also provides a leak detection method for an infrared detector dewar assembly, the leak detection method being implemented by the leak detection system described in any of the above embodiments, the leak detection method comprising the following steps: The control module controls the leak detector to evacuate air until the vacuum degree of detection is reached in the vacuum chamber; wherein the vacuum degree of detection is determined according to the leakage rate requirement of the Dewar assembly to be tested; The control module controls the gas source to release the tracer gas to the area outside the air extraction cavity in the leak detection tool; The leak detector detects the change in the content of the tracer gas in the vacuum chamber and outputs leak detection data; wherein the leak detection data includes a detection leak rate; The control module outputs a leak detection result according to the leak detection data.

[0013] The invention provides a method for leak detection of an infrared detector dewar assembly in an embodiment of the invention, wherein the control module outputs a leak detection result according to the leak detection data, and the method comprises: When the detected leakage rate is greater than the leakage rate threshold, the leakage detection result output by the control module is unqualified; When the detected leakage rate is less than or equal to the leakage rate threshold, the leakage detection result output by the control module is qualified; wherein the leakage rate threshold is set according to the leakage rate requirement of the Dewar assembly to be tested.

[0014] The leak detection method of the infrared detector dewar assembly provided by the embodiment of the present invention, after the control module reads the leak detection data and outputs the leak detection result, the leak detection method further includes: Open the exhaust control valve, start the fan, and extract the tracer gas in the leak detection tooling through exhaust.

[0015] The leak detection system and leak detection method of the infrared detector dewar assembly provided by the invention embodiment can perform leak detection on the dewar assemblies in batches to obtain the leak rate level, adapt to the batch production of the dewar assemblies, and improve the leak detection efficiency.

[0016] The leak detection system and leak detection method of the infrared detector Dewar assembly provided by the embodiments of the present invention are more accurate than the existing leak detection systems and avoid the influence of tracer gas on the leak detection results in an open leak detection environment.

[0017] The leak detection system and leak detection method for the infrared detector dewar assembly provided by the embodiments of the present invention have a higher degree of automation, which can improve the leak detection efficiency while avoiding misjudgment caused by manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0019] Figure 1 It is a structural schematic diagram of a leak detection system of an infrared detector Dewar assembly according to an embodiment of the present invention.

[0020] Figure 2 It is a control schematic diagram of a leak detection system of an infrared detector Dewar assembly according to an embodiment of the present invention.

[0021] Figure 3 The present invention is a flowchart of a method for leak detection of an infrared detector dewar assembly according to an embodiment of the present invention.

[0022] The above drawings include the following reference numerals:

[0023] 1—leak detection tool; 11—base; 12—sealing cover; 13—leak detection station; 14—air extraction chamber; 15—on-off valve; 2—leak detector; 21—bellows; 3—gas source; 31—air flow duct; 32—gas control valve; 33—gas supply device; 4—lifting module; 41—support rod; 5—control module; 6—exhaust module; 61—exhaust control valve; 62—exhaust duct; 63—fan. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0027] Infrared detectors are devices that convert incident infrared radiation signals into electrical signal outputs, capture infrared spectra that are invisible to the human eye, and convert them into visible light or electrical signals for analysis and application. According to different working principles, infrared detectors can be divided into two types: refrigerated and non-refrigerated. The main difference between the two is the different refrigeration temperatures of the detection elements.

[0028] Refrigerated infrared detectors are widely used in long-distance monitoring, target tracking, aerospace, and security monitoring. In order to ensure sensitivity and response speed, the detection element needs to be cooled to a low temperature environment. The detector consists of two parts: a dewar assembly and a refrigerator. The dewar assembly includes a chip and a dewar flask. The chip is encapsulated in the dewar flask, which provides a vacuum working environment for it to prevent external heat changes from affecting the operation of the infrared detector chip.

[0029] With the development of the third generation of infrared detectors, integration and miniaturization have become the mainstream update options. Therefore, the existing Dewar flasks are mostly integrated by welding or bonding, which requires the Dewar assembly to meet higher vacuum requirements as a whole. Vacuum is an important reliability indicator of the Dewar assembly and will directly affect the service life of the Dewar assembly. Leak detection of the Dewar assembly is a key process in detector manufacturing.

[0030] In the prior art, the dewar assembly is evacuated by a helium mass spectrometer molecular pump, and leak detection is performed by spraying helium. The inventor of this case has found that such a leak detection method is mostly used to detect leaks of dewar assemblies one by one or in small batches, and is only applicable to small batch production. When the number of dewar assemblies to be detected is too large, the efficiency of the existing leak detection method is too low.

[0031] In addition, the existing leak detection is carried out in an open environment, and the staff makes leak detection judgments based on the data of the helium mass spectrometer; the gas in the open environment can easily affect the subjective judgment results of the staff, causing misjudgment and affecting the accuracy of leak detection. In addition, manually operating the leak detector and reading the results will also affect the overall leak detection efficiency.

[0032] Accordingly, an embodiment of the present invention provides a leak detection system for a dewar assembly of an infrared detector. The leak detection system provided by this embodiment can automatically perform leak detection, reducing manual operations; at the same time, it can realize leak detection of batch dewar assemblies, meet the needs of mass production, and greatly improve the leak detection efficiency. The dewar assembly to be tested is placed in a closed environment for testing, which is less affected by the gas content in the environment, and the leak detection results are more stable and more accurate, which reduces the influence of the subjective judgment of the staff on the leak detection results, avoids misjudgment, and has higher reliability.

[0033] Reference Figure 1 As shown, in the embodiment of the present invention, the leak detection system includes a leak detection tool 1, a leak detector 2, a gas source 3, a lifting module 4, and a control module 5. The lifting module 4 controls the leak detection tool 1 to provide a closed environment for the Dewar component to be tested, and the leak detector 2 and the gas source 3 extract gas from and pass gas into the leak detection tool 1 to change the internal vacuum degree and gas content. The control module 5 connects and controls the gas source 3, the lifting module 4 and the leak detector 2 to realize automatic leak detection.

[0034] Specifically, refer to Figure 1 As shown, the leak detection tool 1 is configured as a detachable closed box. In this embodiment, preferably, the leak detection tool 1 includes a base 11 and a sealing cover 12; the base 11 and the sealing cover 12 can be spliced ​​to form a closed box, and when the base 11 is fixed, the sealing cover 12 is controlled to rise and fall by the lifting module 4. The interface of the sealing cover 12 is consistent with the interface of the base 11, and the box is sealed when abutting, which can reduce the suction pressure of the molecular pump when the leak detector 2 is evacuated, and isolate the excess tracer gas in the air.

[0035] When the sealing cover 12 is raised, the leak detection tool 1 is opened to facilitate the placement of the internal dewar assembly to be tested. When the sealing cover 12 is lowered, the edge of the sealing cover 12 abuts against the base 11, providing a closed leak detection environment outside the dewar assembly.

[0036] Furthermore, the base 11 is made of stainless steel. Stainless steel has good high and low temperature resistance and good stability. It has good sealing performance when providing a closed environment. Even if the internal vacuum degree changes, the stainless steel material has good anti-deformation ability due to the alloy composition and manufacturing process.

[0037] Furthermore, the sealing cover 12 is connected to the execution end of the lifting module 4, and the lifting or lowering of the sealing cover 12 is controlled by the lifting module 4. The lifting module 4 is provided with a bent support rod 41 and a control end, and the control end is connected to the control module 5. One end of the support rod 41 is fixed to the base 11, and the other end of the support rod 41 is provided as the execution end of the lifting module 4 and connected to the top of the sealing cover 12. Preferably, the support rod 41 can be retracted in the vertical direction, and the support rod 41 can be a sliding rod, a screw rod, an electric lifting rod or other settings that meet the lifting and adjustment requirements.

[0038] In other embodiments of the present invention, the leak detection tool can also be set as other detachable structures that meet the sealing requirements, but is not limited thereto. Regarding the setting of the base 11 and the sealing cover 12 in the present application, the materials of the two can also be set to other materials according to the actual leak detection requirements.

[0039] Further, refer to Figure 1 As shown, the leak detection tool 1 also includes a plurality of leak detection stations 13. The plurality of leak detection stations 13 are simultaneously arranged in a closed leak detection environment, and leak detection can be performed simultaneously, meeting the needs of batch leak detection and adapting to the mass production of Dewar components.

[0040] Next, each leak detection station 13 corresponds to a fixed dewar assembly to be tested. When the dewar assembly to be tested is fixed to the leak detection station 13, the dewar assembly is connected to the air extraction chamber 14 in the leak detection tool 1. It should be noted that the leak detection station 13 is sealed and connected to the corresponding dewar assembly to be tested. In some embodiments, a sealing ring is provided at the position of the leak detection station 13 connected to the air extraction chamber 14, and the interior of the dewar assembly is connected to the air extraction chamber 14 through the contact between the sealing ring and the dewar assembly.

[0041] Specifically, the leak detector 2 is sealed and connected to the leak detection tool 1. The interface of the leak detector 2 leads to a bellows 21, and the other end of the bellows 21 is connected to the leak detection tool 1, specifically connected to the air extraction chamber 14 inside the leak detection tool 1.

[0042] The leak detector 2 is used to control the vacuum degree in the vacuum chamber 14 and detect the gas leakage rate in the vacuum chamber 14. In the embodiment of the present invention, the leak detector 2 is configured as a helium mass spectrometer. The helium mass spectrometer can detect extremely small gas leaks, has high sensitivity, and can meet the leak detection requirements of the Dewar assembly. At the same time, the helium mass spectrometer has a fast response speed, strong data reliability, and is easy to maintain.

[0043] Furthermore, in an embodiment of the present invention, each leak detection station 13 is connected to the same vacuum chamber 14, and the Dewar components are preliminarily screened in batches through the leak detection results in the vacuum chamber 14. An independently controlled switch valve 15 is also provided on the leak detection station 13, and each leak detection station 13 is provided with a switch valve 15; the switch valve 15 is used to control the on-off between the Dewar assembly and the vacuum chamber 14 on the leak detection station 13. In some embodiments, the switch valve 15 can be manually controlled to open and close. In other embodiments, the switch valve 15 can also be electrically opened and closed by the control module 5. The electric control method has a higher degree of automation than manual control, and the control operation can be achieved without opening the sealing cover 12.

[0044] Specifically, the gas source 3 used in the leak detection system corresponds to a helium mass spectrometer set as a helium gas source. Helium, as an inert gas, is not easy to react with the object to be detected and is an ideal tracer gas in the leak detection process. The gas source 3 is sealed and connected to the leak detection tool 1. The gas source 3 is used to release the tracer gas into the leak detection tool 1. In this embodiment, the tracer gas is set to helium.

[0045] The gas source 3 includes a gas supply device 33, a gas flow pipeline 31 and a gas control valve 32. One end of the gas flow pipeline 31 is connected to the gas supply device 33, and the other end of the gas flow pipeline 31 is connected to the area outside the vacuum chamber 14 inside the leak detection tool 1, and sprays the tracer gas thereto. The gas control valve 32 is arranged on the gas flow pipeline 31, and is used to control the gas flow in the gas flow pipeline 31.

[0046] Further, the gas control valve 32 is configured as a gas flow control valve, or the gas control valve 32 is configured as a gas pressure control valve.

[0047] When the gas control valve 32 is configured as a gas flow control valve, it is used to maintain the flow rate of the tracer gas in the gas flow pipeline 31, and to adjust the gas flow rate through the gas control valve 32 by changing the size of the valve port ventilation area. When the gas control valve 32 is configured as a gas pressure control valve, it is used to maintain or adjust the pressure of the tracer gas pumped out at the valve port.

[0048] Specifically, refer to Figure 2 As shown, the control module 5 is used to realize the automation of the leak detection process, specifically for connecting and controlling the leak detector 2, the gas source 3 and the lifting module 4. The control module 5 includes a display screen, an air jet control button, a leak detection control button and a lifting control button; wherein the display screen is used to display the leak detection result. The spray control button is used to control the gas source 3, the leak detection control button is used to control the leak detector 2, and the lifting control button is used to control the lifting module 4.

[0049] Furthermore, the control module 5 controls the leak detector 2 to evacuate the inside of the leak detection tool 1 to create a low-helium environment. At the same time, the leak detection data is read when the leak detector 2 detects the leakage rate in the exhaust chamber 14. The control module 5 is connected to the gas control valve 32, which controls whether the tracer gas is released on the one hand, and controls the flow rate or pump pressure when the tracer gas is released on the other hand. The control module 5 is connected to the lifting module 4, and controls the lifting and lowering of the sealing cover 12 through the execution end of the lifting module 4, thereby controlling the opening or closing of the box of the leak detection tool 1.

[0050] Specifically, refer to Figure 1 As shown, the leak detection system of the infrared detector Dewar assembly provided in the embodiment of the present invention also includes an exhaust module 6. The exhaust module 6 is arranged on the top of the sealing cover 12. The exhaust module 6 includes a fan 63, an exhaust duct 62 and an exhaust control valve 61 arranged on the exhaust duct 62. One end of the exhaust duct 62 is connected to the area outside the vacuum chamber 14 in the leak detection tool 1, and the other end of the exhaust duct 62 is connected to the fan 63. The exhaust duct 62 is set as a polyvinyl chloride pipe, and the exhaust control valve 61 is used to control the on and off of the exhaust duct 62.

[0051] By setting the exhaust component, the gas inside the leak detection tool 1 can be discharged after the leak detection is completed, especially the residual helium inside can be discharged, so as to keep the detection environment of the entire leak detection system clean. It is prevented that the residual helium will pollute the leak detector 2 or cause a heavy burden on the leak detector 2, affecting the service life and leak detection accuracy of the leak detector 2, and constructing the initial detection environment for the subsequent batches of Dewar component leak detection.

[0052] Reference Figure 3As shown, an embodiment of the present invention also provides a leak detection method for an infrared detector dewar assembly, and the leak detection method is implemented by the leak detection system of the infrared detector dewar assembly. Therefore, the leak detection method includes all the technical effects of the leak detection system of the infrared detector dewar assembly. Since the technical effects of the leak detection system have been described in detail above, they will not be repeated here.

[0053] Specifically, the leak detection method of the infrared detector Dewar assembly includes the following steps:

[0054] The sealing cover 12 is lowered by the lifting control button of the control module 5 to abut against the base 11 to form a sealed environment.

[0055] The leak detector 2 is controlled to evacuate gas through the leak detection control button of the control module 5, and the gas in the closed environment is extracted through the bellows 21, so as to provide a low-helium environment for the leak detection station 13 and the Dewar assembly to be tested.

[0056] The sealing cover 12 is raised by the lifting control button of the control module 5, and the Dewar components to be tested are fixed one by one to the leak detection station 13, and the switch valve 15 is kept open. After the fixing is completed, the sealing cover 12 is dropped to abut against the base 11 and sealed.

[0057] The leak detector 2 is controlled to evacuate air through the leak detection control button of the control module 5 until the inside of the evacuation chamber 14 in the leak detection tool 1 reaches the detection vacuum degree. The detection vacuum degree is determined according to the leakage rate requirement of the Dewar assembly to be tested.

[0058] It should be noted that the leakage rate requirement is set to one of the first-level leakage rate, second-level leakage rate, third-level leakage rate, fourth-level leakage rate and fifth-level leakage rate. When the leakage rate level is different, the corresponding leakage volume is different compared to the volume of the workpiece to be measured. Therefore, the requirement for the leakage rate is determined based on the leakage volume and the volume of the workpiece to be measured.

[0059] In this embodiment, if the leakage rate requirement is to detect whether the Dewar assembly meets the third-level leakage rate, then according to the requirement that the leakage amount of the third-level leakage rate does not exceed one ten-thousandth, the total amount of gas in the exhaust chamber 14 is controlled to be about one ten-thousandth of the volume of the Dewar assembly to be tested, and when the tracer gas content therein is controlled to be below one ten-thousandth, the vacuum degree in the exhaust chamber 14 is reached.

[0060] The gas control valve 32 of the gas source 3 is opened by controlling the jet control button of the control module 5 , and the tracer gas is released to the area outside the vacuum chamber 14 in the leak detection tool 1 through the air flow pipeline 31 , specifically, helium is sprayed into the area.

[0061] After the tracer gas is injected, part of the tracer gas enters the pumping chamber 14 through the leak of the Dewar assembly, causing the content of the tracer gas in the pumping chamber 14 to change. The leak detector 2 captures and detects the change in the gas content in the pumping chamber 14 and outputs leak detection data according to the content change. The leak detection data includes the detection leak rate required to determine the leak rate level, and the detection leak rate is used to provide a basis for the judgment output of the detection module.

[0062] The control module 5 outputs the leak detection result according to the leak detection data:

[0063] When the detected leakage rate is greater than the leakage rate threshold, the control module 5 outputs a leakage detection result as unqualified, and displays an "NG" mark on the display screen.

[0064] When the detected leakage rate is less than or equal to the leakage rate threshold, the control module 5 outputs a qualified leakage detection result and displays an "OK" mark on the display screen. The leakage rate threshold is preset according to the leakage rate requirement of the Dewar assembly to be tested, and different leakage rate thresholds are required for different leakage rate levels.

[0065] After the leak detection result is output, the exhaust control valve 61 is opened, and the fan 63 is started to extract the tracer gas in the leak detection tool 1 through exhaust to complete the leak detection of this batch of Dewar components.

[0066] The infrared detector dewar assembly leak detection method provided by the embodiment of the present invention only requires manual fixing of the dewar assembly to be tested at the leak detection station. After startup, the system will automatically lock, evacuate and spray helium, and judge whether the leak rate level is qualified. The high degree of automation greatly improves the leak detection efficiency. At the same time, compared with manual judgment, automated leak detection can also reduce misjudgment and improve the accuracy of leak detection.

[0067] It should be noted that, since the exhaust cavities 14 of the multiple leak detection stations 13 are interconnected, when the display screen displays the "OK" mark, it means that the multiple Dewar assemblies at the multiple stations all meet the leak rate level requirements, and the Dewar assemblies can be subjected to batch initial screening and initial inspection. When the display screen displays the "NG" mark, it means that there are Dewar assemblies in the multiple stations whose leak rate levels do not meet the requirements.

[0068] If it is necessary to detect one or several Dewar components that do not meet the leak rate level in multiple stations, re-inspection can be performed after the leak detection results are output.

[0069] When the switch valve 15 is manually controlled, the re-inspection process includes: after the exhaust module 6 completes the exhaust, the sealing cover 12 is raised through the control module 5, and the switch valve 15 is manually operated, and the switch valve 15 corresponding to the Dewar component that needs to be re-inspected is kept open, and the switch valve 15 corresponding to the Dewar component that does not need to participate in the re-inspection is closed. Thereafter, all steps of the above-mentioned leak detection method are repeated, and the leak detection results output by the re-inspection are used to determine whether the leakage rate of one or several Dewar components in the initial inspection meets the requirements.

[0070] Alternatively, the re-inspection process includes: after the exhaust module 6 completes exhaust, the sealing cover 12 is raised by the control module 5, the dewar components that are no longer involved in the re-inspection are taken out, and the dewar components that need to be involved in the re-inspection are retained. Thereafter, all steps of the above-mentioned leak detection method are repeated, and the leak detection results output by the re-inspection are used to determine whether the leakage rate of one or several dewar components in the initial inspection meets the requirements.

[0071] When the switch valve 15 is controlled by the control module 5, the re-inspection process includes: after the exhaust module 6 completes the exhaust, the abutment relationship between the sealing cover 12 and the base 11 is kept unchanged. The switch valves 15 of each leak detection station 13 are controlled by the control module 5 to control the on-off of the Dewar assembly and the air extraction chamber 14. The switch valve 15 corresponding to the Dewar assembly that needs to be re-inspected is kept open, and the switch valve 15 corresponding to the Dewar assembly that does not need to participate in the re-inspection is closed. Repeat the process of exhausting the air extraction chamber 14 and spraying the tracer gas in the air flow pipeline 31, and then judge whether the leakage rate level of the Dewar assembly connected to the air extraction chamber 14 meets the requirements through the mark on the display screen.

[0072] Manual control of the on-off valve requires opening the sealing cover to operate, which can prevent residual gas from affecting the results of re-inspection during batch testing. The control module controls the on-off valve without raising the sealing cover, which makes leak detection more efficient.

[0073] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0074] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0075] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A leak detection system for an infrared detector dewar assembly, characterized in that: include: Leak detection tooling, leak detector and gas source; The leak detection tool is configured as a detachable closed box, and the leak detection tool comprises a plurality of leak detection stations, each of which is sealed and fixed with a dewar assembly to be tested, and the dewar assembly to be tested is connected to the air extraction chamber in the leak detection tool when fixed to the leak detection station; The leak detector is sealed and connected to the leak detection tooling, and is communicated with the interior of the air extraction cavity; The gas source is sealed and connected to the leak detection tool, and is communicated with the area outside the air extraction cavity in the leak detection tool, and the gas source is used to release the tracer gas.

2. The leak detection system of the infrared detector dewar assembly according to claim 1, characterized in that: The leak detection tool also includes a base and a sealing cover, and the leak detection system also includes a lifting module; The execution end of the lifting module is connected to the sealing cover, and the lifting module is used to control the sealing cover to rise or fall; when the sealing cover falls, it abuts against the base to make the closed box airtight.

3. The leak detection system of the infrared detector dewar assembly according to claim 2, characterized in that: Also includes a control module; The control module is connected to the leak detector, and the control module controls the leak detector to evacuate air and reads the leak detection data of the leak detector; The control module is connected to the gas source, and the control module controls the gas source to release the tracer gas; The control module is connected to the lifting control module, and controls the lifting of the sealing cover through the lifting control module.

4. The leak detection system of the infrared detector dewar assembly according to claim 3, characterized in that: Each of the leak detection stations is provided with a switch valve, and the switch valve is used to independently control the on-off between the Dewar assembly to be tested and the air pumping chamber; The switch valve is configured to be manually controlled, or the switch valve is configured to be controlled by the control module.

5. The leak detection system of the infrared detector dewar assembly according to claim 1, characterized in that: Also includes an exhaust module; The exhaust module includes a fan, an exhaust duct and an exhaust control valve arranged on the exhaust duct; one end of the exhaust duct is connected to the area outside the vacuum chamber in the leak detection tooling, and the other end of the exhaust duct is connected to the fan; the exhaust control valve is used to control the on and off of the exhaust duct.

6. The leak detection system of the infrared detector dewar assembly according to claim 1, characterized in that: The gas source includes an air flow pipeline and a gas control valve arranged on the air flow pipeline; the air flow pipeline is connected to the area outside the air extraction cavity in the leak detection tool.

7. The leak detection system of the infrared detector dewar assembly according to claim 6, characterized in that: The gas control valve is configured as a gas flow control valve, or the gas control valve is configured as a gas pressure control valve.

8. A method for leak detection of an infrared detector dewar assembly, characterized in that: The leak detection method is implemented by the leak detection system according to any one of claims 1 to 7, and the leak detection method comprises the following steps: The control module controls the leak detector to evacuate air until the vacuum degree of detection is reached in the vacuum chamber; wherein the vacuum degree of detection is determined according to the leakage rate requirement of the Dewar assembly to be tested; The control module controls the gas source to release the tracer gas to the area outside the air extraction cavity in the leak detection tool; The leak detector detects the change in the content of the tracer gas in the vacuum chamber and outputs leak detection data; wherein the leak detection data includes a leak rate; The control module outputs a leak detection result according to the leak detection data.

9. The method for leak detection of infrared detector dewar assembly according to claim 8, characterized in that: The control module outputs the leak detection result according to the leak detection data, including: When the detected leakage rate is greater than the leakage rate threshold, the leakage detection result output by the control module is unqualified; When the detected leakage rate is less than or equal to the leakage rate threshold, the leakage detection result output by the control module is qualified; wherein the leakage rate threshold is set according to the leakage rate requirement of the Dewar assembly to be tested.

10. The method for leak detection of infrared detector dewar assembly according to claim 8, characterized in that: After the control module reads the leak detection data and outputs the leak detection result, the leak detection method further includes: Open the exhaust control valve, start the fan, and extract the tracer gas in the leak detection tooling through exhaust.

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