Magnetron dual-mode leak detection machine and leak detection method

Abstract

The invention relates to the technical field of magnetron leak detection machines, and particularly discloses a magnetron dual-mode leak detection machine which comprises a tool table, a helium release mechanism, a dual-mode control gas circuit, a vacuum pump and a helium detector. The tool table comprises a detection table, a lifting mounting plate and a positioning sealing mechanism, and a first lifting air cylinder is arranged on the detection table; the positioning and sealing mechanism comprises a pressing sleeve and an elastic sealing piece; the dual-mode control gas circuit comprises a main pipeline and a branch pipeline; the first end of the branch pipeline is communicated with the upper surface from the bottom surface of the detection table, the second end of the branch pipeline is communicated with the first end of the main pipeline, the second end of the main pipeline is connected with the gas inlet end of the helium detector, and the gas outlet end of the helium detector is connected with the vacuum pump. According to the invention, the magnetron butt joint, gas leakage rough detection, helium release and gas leakage accurate detection procedures can be automatically completed, the detection efficiency is high, the detection process does not need manual intervention, and the automation degree is high.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetron leak detectors, and in particular to a magnetron dual-mode leak detector and a leak detection method. Background Art

[0002] During the production process of a magnetron, it is necessary to detect the leak of the magnetron housing by means of vacuum pumping. The magnetron housing mainly includes a main cavity and an antenna tube communicating with the main cavity. The existing leak detection equipment mainly uses a vacuum suction pipe to connect to the antenna tube, pump out the air inside the main cavity and the antenna tube, and then maintain the pressure for a predetermined time. If the pressure maintenance is successful, it means that the magnetron has no leakage. However, in the above method, workers need to connect the antenna tube of the magnetron to the vacuum joint, and after detection, they need to pull the magnetron out of the vacuum joint forcefully, and the operation is relatively cumbersome. Moreover, only one magnetron can be detected at a time, and each detection requires a pressure maintenance time, so the efficiency is low.

[0003] In addition, the existing detectors can only achieve vacuum leak detection or helium leak detection. Using negative pressure vacuum leak detection requires a large negative pressure to be applied by a vacuum pump, the negative pressure formation time is long, the energy consumption is high, and the detection efficiency is low; using helium leak detection alone requires a large amount of helium, and the use cost is high. Summary of the Invention

[0004] In order to solve the defects of the prior art, the present invention provides a magnetron dual-mode leak detector and a leak detection method, which can automatically complete the procedures of magnetron docking, rough leak detection, helium release, and precise leak detection, with high detection efficiency, no manual intervention required during the detection process, and high automation degree.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a device including a tooling table, a helium release mechanism, a dual-mode control gas path, a vacuum pump, and a helium detector;

[0006] The tooling table includes a detection table, a lifting mounting plate, and a positioning and sealing mechanism,

[0007] A first lifting cylinder is provided on the detection table, and the lifting mounting plate is connected to the first lifting cylinder;

[0008] The positioning and sealing mechanism includes a pressing sleeve and an elastic seal, and the elastic seal is arranged below the pressing sleeve;

[0009] The helium release mechanism is used to release helium around the magnetron in the helium leak detection mode;

[0010] The dual-mode control gas path includes a main pipeline and a branch pipeline; the first end of the branch pipeline communicates from the bottom surface of the detection table to the upper surface, the second end of the branch pipeline is connected to the first end of the main pipeline, the second end of the main pipeline is connected to the air inlet end of the helium detector, and the air outlet end of the helium detector is connected to the vacuum pump;

[0011] The first end of the main pipeline is coiled to form an enclosing frame, and the branch pipeline is connected within the enclosing frame.

[0012] As an improvement to the above solution, a negative pressure detection pipe is provided on the detection table, and the negative pressure detection pipe is opposite to the pressing sleeve; the elastic seal is provided between the pressing sleeve and the negative pressure detection pipe; the first end of the branch pipeline is connected to the negative pressure detection pipe.

[0013] As an improvement to the above solution, adjacent two branch pipelines are arranged in a staggered manner within the enclosing frame. The first end of the branch pipeline is formed with a bent section, the end of the bent section is communicated with the negative pressure detection pipe, and the ends of multiple bent sections are located on the same straight line.

[0014] As an improvement to the above solution, the main pipeline includes a pressure-holding section. The first end of the pressure-holding section is connected to the vacuum pump in a switchable manner. The second end of the pressure-holding section is wound to form the enclosing frame, and a vacuum detector is arranged on the pressure-holding section.

[0015] As an improvement to the above solution, a first control valve is arranged between the pressure-holding section and the vacuum pump; the main pipeline further includes a gas detection section. The first end of the gas detection section is connected to the enclosing frame in a switchable manner, and the second end of the gas detection section is connected with the helium detector; a second control valve is arranged between each branch pipeline and the negative pressure detection pipe; a third control valve is arranged between the first end of the gas detection section and the enclosing frame.

[0016] As an improvement to the above solution, each branch pipeline is provided with an elastic shock-absorbing pipe, and the elastic shock-absorbing pipes are connected through quick connectors.

[0017] As an improvement to the above solution, the helium release mechanism includes a lifting drive mechanism, a lifting seat and a helium release cover,

[0018] The lifting drive mechanism includes a slide rail vertically arranged on the tooling table, a slider slidably arranged on the slide rail, and a second lifting cylinder for driving the lifting seat to lift. The lifting seat is arranged on the slider; the helium release cover is provided with an air inlet end.

[0019] As an improvement of the above solution, the lifting mounting plate is provided with mounting holes, and the pressing sleeve is arranged in the mounting holes and extends towards the inspection table; the negative pressure detection tube is provided with a guiding cavity, a support ring is arranged at the bottom of the guiding cavity, and the elastic seal is supported on the support ring.

[0020] As an improvement of the above solution, the elastic seal includes a first sealing ring, a metal ring and a second sealing ring which are arranged in sequence from top to bottom.

[0021] As an improvement of the above solution, the outer wall of the pressing sleeve has a pressure-bearing ring, the upper end of the pressure-bearing ring has a first installation pipe section for extending into the mounting hole; a first conical surface is arranged on the inner wall of the first installation pipe section; a guiding head is further arranged on the lifting mounting plate, and a second conical surface is arranged on the inner wall of the guiding head.

[0022] As an improvement of the above solution, a connecting rod is arranged at the top of the helium release cover, a through hole is arranged on the lifting seat, and the connecting rod passes through the through hole; a limiting block is fixedly arranged on the upper part of the connecting rod, and the distance between the limiting block and the helium release cover is greater than the length of the through hole.

[0023] As an improvement of the above solution, the air inlet end includes an upper air inlet end and a side air inlet end, the connecting rod has an air duct, one end of the air duct is communicated to the top of the inner cavity of the helium release cover, and the other end is connected to the upper air inlet end; the side air inlet end is communicated to the side part of the inner cavity of the helium release cover.

[0024] As an improvement of the above solution, the helium release cover includes an outer shell and an inner liner, the inner liner is arranged in the outer shell, and an air ventilation gap is arranged between the inner liner and the outer shell; a first air outlet hole is arranged at the top of the inner liner, and a second air outlet hole is arranged on the lower side surface; the connecting rod is directly connected to the first air outlet hole, and the side air inlet end is communicated with the air ventilation gap.

[0025] Correspondingly, the present invention further provides a method for detecting leaks in a magnetron in two modes, using the magnetron leak detector in two modes as described above, including the following steps:

[0026] S1. Connect the magnetron: Install the magnetron on the lifting mounting plate, and the antenna of the magnetron extends into the elastic seal; the first lifting cylinder drives the pressing sleeve to descend to compress the elastic seal, and the elastic seal seals and connects the antenna with the negative pressure detection tube;

[0027] S2. Rough air inspection: Open the first control valve and the second control valve, close the third control valve, and the vacuum pump evacuates all the magnetrons installed on the lifting mounting plate through the main pipeline and the branch pipeline; after a certain period of time, if the vacuum degree of the vacuum detector reaches the preset threshold, go to step S4, otherwise go to step S3;

[0028] S3. Fine air inspection: Keep the vacuum pump working and open the first control valve; close the second control valve and the third control valve, and then open the second control valve one by one. If the vacuum degree of the vacuum detector changes when a certain second control valve is opened, mark the corresponding magnetron.

[0029] S4. Helium release mechanism preparation: The lifting seat drives the helium release cover to descend, and the helium release cover covers the magnetron.

[0030] S4. Helium leak detection; The helium release cover releases helium to the periphery of the magnetron. Open the third control valve, close the first control valve, keep the second control valve corresponding to the marked magnetron closed, and open the remaining second control valves one by one. The vacuum pump evacuates the magnetrons installed on the lifting mounting plate through the main pipeline and the branch pipelines. The extracted gas passes through the helium detector. When the helium passing through the helium detector is less than the preset value, this magnetron is qualified; otherwise, it is listed as a defective product together with the magnetrons marked in other steps.

[0031] As an improvement of the above solution, the preset threshold of the vacuum detector in step S2 is 1000 pa - 100 pa; the set vacuum pressure of the vacuum pump in step S4 is 10 pa - 0.1 pa.

[0032] Implementing the embodiments of the present invention has the following beneficial effects:

[0033] This device realizes the rough inspection and fine inspection of the sealing performance of the magnetron through the cooperation of two detection modes. Among them, by opening the first control valve and closing the third control valve, the main pipeline and the branch pipelines are directly connected to the vacuum pump, and the vacuum detector set on the main pipeline can be used to conduct a rough inspection of the magnetron. This detection uses a relatively low vacuum degree, can quickly form the required negative pressure detection environment by using the vacuum pump, and does not require the use of specific gases, with high detection efficiency and low cost. It can exclude magnetrons with relatively large manufacturing defects at this stage, such as magnetrons with visible holes or cracks at the joints. Then, by closing the first control valve and opening the third control valve, the main pipeline and the branch pipelines are connected to the vacuum pump through the helium detector, and it is detected whether the helium outside the magnetron enters the dual-mode control gas path through the helium detector, so as to detect whether the magnetron has leakage. On the one hand, this mode utilizes the strong penetrability of helium, which can easily pass through tiny cracks and holes. On the other hand, by increasing the negative pressure setting value of the vacuum pump, the helium outside the magnetron is more likely to enter the magnetron and is finally detected, improving the detection accuracy. With the above structure, it can automatically complete the procedures of magnetron docking, rough air leakage measurement, helium release, and fine air leakage measurement, with high detection efficiency, no need for manual intervention during the detection process, and high automation degree. Description of the Drawings

[0034] Figure 1 is the overall structural schematic diagram of a dual-mode leak detector for magnetrons of the present invention;

[0035] Figure 2 is a schematic structural diagram of a dual-mode control gas path according to an embodiment of the present invention;

[0036] Figure 3 is a schematic structural diagram of a branch pipeline according to an embodiment of the present invention;

[0037] Figure 4 is a schematic overall structural diagram of a tooling table according to an embodiment of the present invention;

[0038] Figure 5 is a schematic structural diagram of another perspective of the tooling table according to an embodiment of the present invention;

[0039] Figure 6 is a cross-sectional view of the tooling table according to an embodiment of the present invention;

[0040] Figure 7 is a schematic overall structural diagram of a helium release mechanism according to an embodiment of the present invention;

[0041] Figure 8 is a schematic structural diagram of another perspective of the helium release mechanism according to an embodiment of the present invention;

[0042] Figure 9 is a cross-sectional view of a helium release cover according to an embodiment of the present invention;

[0043] Figure 10 is a flowchart of magnetron dual-mode leak detection according to the second embodiment of the present invention. Detailed implementation manners

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It is hereby declared that the orientation terms such as up, down, left, right, front, back, inside, and outside that appear or will appear in the text of the present invention are only based on the accompanying drawings of the present invention, and they do not specifically limit the present invention.

[0045] As Figure 1As shown in the figure, the first embodiment of the present invention provides a magnetron dual-mode leak detector, which includes a tooling table 1, a helium release mechanism 2, a dual-mode control gas path 3, a vacuum pump 4, and a helium detector 5. The tooling table 1 includes a detection table 11, a lifting mounting plate 12, and a positioning and sealing mechanism. A first lifting cylinder 13 is provided on the detection table 11, and the lifting mounting plate 12 is connected to the first lifting cylinder 13. The positioning and sealing mechanism includes a pressing sleeve 14 and an elastic seal 15; a negative pressure detection tube 16 is provided on the detection table 11, and the negative pressure detection tube 16 is opposite to the pressing sleeve 14; the elastic seal 15 is provided between the pressing sleeve 14 and the negative pressure detection tube 16. The helium release mechanism 2 includes a lifting drive mechanism, a lifting seat 21, and a helium release cover 22. The lifting drive mechanism includes a slide rail 23 vertically provided on the tooling table 1, a slider 24 slidably provided on the slide rail 23, and a second lifting cylinder 25 for driving the lifting seat 21 to lift. The lifting seat 21 is provided on the slider 24; the helium release cover 22 is provided with an air inlet end 26.

[0046] Combined with Figure 2 and Figure 3 As shown in the figure, the dual-mode control gas path 3 is used to meet the gas control requirements of two modes of air leak detection and helium leak detection, and includes a main pipeline 31 and a branch pipeline 32; the first end of each branch pipeline 32 is communicated with one of the negative pressure detection tubes 16, the second end of each branch pipeline 32 is communicated with the first end of the main pipeline 31, the second end of the main pipeline 31 is connected to the air inlet end of the helium detector 5, and the air outlet end of the helium detector 5 is connected to the vacuum pump 4;

[0047] The first end of the main pipeline 31 is coiled to form an enclosing frame 311, and multiple branch pipelines 32 are all located within the enclosing frame 311.

[0048] This leak detector is equipped with a tooling table 1, a helium release mechanism 2, and a dual-mode control gas path 3. Workers can use the tooling table 1 to fix the antennas of multiple magnetrons and connect them to the dual-mode control gas path 3. The remaining parts of the magnetrons are covered by the helium release hood 22 of the helium release mechanism 2, and helium is released. Then, the vacuum pump 4 evacuates the inside of the magnetrons through the dual-mode control gas path 3. Through the cooperation of two detection modes, rough inspection and fine inspection of the sealing performance of the magnetrons are realized. Among them, by opening the first control valve and closing the third control valve, the main pipeline 31 and the branch pipeline 32 are directly connected to the vacuum pump, and a vacuum detector provided on the main pipeline 31 can be used to conduct a rough inspection of the magnetrons. The vacuum degree used in this detection is relatively low, which can quickly form the required negative pressure detection environment by using the vacuum pump, and there is no need to use specific gases. The detection efficiency is high and the cost is low, and magnetrons with relatively large manufacturing defects can be excluded at this stage, such as magnetrons with visible holes or cracks at the joints. Then, by closing the first control valve and opening the third control valve, the main pipeline 31 and the branch pipeline 32 are connected to the vacuum pump through the helium detector 5. Whether there is helium outside the magnetrons entering the dual-mode control gas path 3 is detected through the helium detector 5, so as to detect whether the magnetrons have leaks. On the one hand, this mode utilizes the strong penetrability of helium, which can easily pass through tiny cracks and holes. On the other hand, by increasing the negative pressure setting value of the vacuum pump 4, the helium outside the magnetrons is more likely to enter the inside of the magnetrons and is finally detected, improving the detection accuracy. With the above structure, the procedures of docking, rough leak detection, helium release, and fine leak detection of the magnetrons can be automatically completed. The detection efficiency is high, the detection process does not require manual intervention, and the degree of automation is high.

[0049] The specific composition of the dual-mode control gas path 3 in this embodiment is described in detail below: Adjacent two of the branch pipelines 32 are arranged in a staggered manner within the enclosure frame 311 to avoid mutual intersection and bending entanglement between multiple branch pipelines 32, further improving the chaotic arrangement of multiple branch pipelines 32 within the enclosure frame 311 and ensuring the neat and orderly layout of the internal pipelines of the gas path system. A bent section 321 is formed at the first end of the branch pipeline 32, and the end of the bent section 321 is communicated with the negative pressure detection tube 16, and the ends of multiple bent sections 321 are located on the same straight line, so that adjacent two branch pipelines 32 can use their respective bent sections 321 to communicate with the corresponding negative pressure detection tubes.

[0050] The main pipeline 31 includes a pressure-holding section 312. The first end of the pressure-holding section 312 is connected to and disconnected from the vacuum pump 4. The second end of the pressure-holding section 312 is wound to form the enclosing frame 311. A vacuum detector 33 is arranged on the pressure-holding section 312. Further, when performing vacuum pressure-holding detection, the pressure-holding section 312 can be connected to the vacuum pump 4. The vacuum pump 4 evacuates the magnetron through the pressure-holding section 312 and the branch pipeline 32. At this time, whether there is a leak point in the magnetron can be judged according to the vacuum degree value of the vacuum detector 33. Specifically, when the vacuum degree value can reach the preset value within a certain time, it indicates that the magnetron being detected at this time has no leak point; if the vacuum degree value cannot reach the preset value within a certain time, it indicates that there is a leak point in the magnetron.

[0051] A first control valve 34 is arranged between the pressure-holding section 312 and the vacuum pump; the main pipeline 31 further includes a gas detection section 313. The first end of the gas detection section 313 is connected to and disconnected from the enclosing frame 311. The second end of the gas detection section 313 is connected with the helium detector 5; a second control valve 35 is arranged between each branch pipeline 32 and the negative pressure detection pipe; a third control valve 36 is arranged between the first end of the gas detection section 313 and the enclosing frame 311.

[0052] The first control valve 34 can be used as a rough inspection valve of the gas circuit system. The first control valve 34 is used to control the on-off between the pressure-holding section 312 and the vacuum pump 4, and correspondingly control the start and stop of the vacuum pressure-holding detection. Among them, when evacuating the magnetron by the vacuum pump, the first control valve 34 is fully opened to ensure the high pumping speed of the vacuum pump 4 for the magnetron; during the pressure-holding detection, the first control valve 34 is closed, so that the inner cavity of the magnetron, the branch pipeline 32 and the pressure-holding section 312 form a closed environment, so as to judge the leakage rate of the magnetron according to the vacuum degree value of the vacuum detector 33. The second control valve 35 can be used as a single inspection valve in the gas circuit system. When performing vacuum pressure-holding detection on multiple magnetrons at the same time, multiple second control valves 35 are opened at the same time. When performing inflation fine inspection on a single magnetron, the second control valve 35 at the corresponding position can be opened separately, and other second control valves 35 are closed at the same time, so as to judge whether there is a leak point in the magnetron at the corresponding position. The third control valve 36 can be used as a fine inspection valve of the gas circuit system. The third control valve 36 is used to control the on-off between the gas detection section 313, the enclosing frame 311 and the branch pipeline 32, and correspondingly control the switching between the vacuum pressure-holding detection and the inflation detection.

[0053] Preferably, each branch pipeline 32 is provided with an elastic damping tube 322. The elastic damping tube 322 can absorb the vibration transmission of the vacuum pump to the branch pipeline 32, thereby reducing the noise influence generated by the branch pipeline 32 during the operation of the vacuum pump. The elastic damping tubes 322 are connected by quick connectors 323 to facilitate the quick installation and disassembly of the branch pipeline 32 in the gas circuit system.

[0054] The specific composition of the tooling table 1 of this embodiment will be described in detail below: As Figures 4 - 6 shown, the elastic seal 15 has a through hole, the lifting mounting plate 12 is provided with a mounting hole 121, and the pressing sleeve 14 is arranged in the mounting hole 121 and extends towards the inspection table 11. The elastic seal 15 includes a first sealing ring 151, a metal ring 152, and a second sealing ring 153 arranged in sequence from top to bottom. The negative pressure detection tube 16 is provided with a guiding cavity 161, and a support ring 162 is arranged at the bottom of the guiding cavity 161. The elastic seal 15 is supported on the support ring 162. During detection, the antenna of the magnetron to be detected can extend into the through hole, and the pressing sleeve 14 applies pressure downward from the top of the elastic seal 15 to keep the outer wall of the antenna sealed with the support ring 162.

[0055] It should be noted that the metal ring 152 allows the antenna to pass through and positions the first sealing ring 151 above it and the second sealing ring 153 below it. When the pressing sleeve 14 is pressed down, the first sealing ring 151 and the second sealing ring 153 extend radially to fix and double-seal the outer wall of the antenna, facilitating subsequent tests such as vacuum leak detection and helium leak detection. With the above structure, workers can easily install the magnetron to be detected into the pressing sleeve 14. Then, the lifting mounting plate 12 drives the negative pressure detection tube 16 to descend. Since the negative pressure detection tube 16 is aligned with the pressing sleeve 14, the antenna of the magnetron can be docked with the negative pressure detection tube 16, and the elastic seal 15 is used to form a sealed connection between the antenna of the magnetron and the negative pressure detection tube 16, so that the negative pressure mechanism connected to the negative pressure detection tube 16 can extract the air inside the magnetron and perform pressure holding detection and other tests. After the test is completed, the lifting mounting plate 12 rises, and the elastic seal 15 uses its own elasticity to reset and automatically release the magnetron to be detected. Workers can conveniently take out the magnetron and perform the detection work on another batch of magnetrons. The working intensity of workers is low, and the detection efficiency is high.

[0056] To improve the maintenance convenience of this tooling platform, the outer wall of the pressing sleeve 14 has a pressure-bearing ring 141, and the upper end of the pressure-bearing ring 141 has a first installation pipe section 142 for extending into the installation hole 121. The pressing sleeve 14 is limited and guided by the installation hole 121 and can axially move within a certain range. When maintenance is required, only the bolt 131 connecting the telescopic rod of the first lifting cylinder 13 needs to be loosened, and the lifting mounting plate 12 can be removed. The pressing sleeve 14 is automatically separated from the lifting mounting plate 12, and the disassembly and assembly are convenient.

[0057] When the worker places the magnetron into the lifting mounting plate 12, the antenna of the magnetron first contacts the middle channel of the pressing sleeve 14, which is prone to rigid collision, causing pits at the end of the antenna of the magnetron and affecting the quality of the finished product. To solve the above problems, a first conical surface 143 is provided on the inner wall of the first mounting pipe section 142 in this embodiment. When the magnetron is inserted into the pressing sleeve 14, it first contacts the first conical surface 143, and reaches a vertical state and extends into the middle channel of the pressing sleeve 14 under the guiding action of the first conical surface 143.

[0058] Preferably, a guiding head 17 is further provided on the lifting mounting plate 12, and a second conical surface 171 is provided on the inner wall of the guiding head 17. The guiding head 17 has a second mounting pipe section 172, and the mounting hole 121 is threadedly connected to the second mounting pipe section 172; the first mounting pipe section 142 is sleeved in the second mounting pipe section 172. The guiding head 17 can be screwed into the mounting hole 121 from above the lifting mounting plate 12 through the thread on the outside of the second mounting pipe section 172, and the guiding head 17 can be disassembled and assembled by wirelessly disassembling the lifting mounting plate 12.

[0059] More preferably, the diameter of the opening at the top of the second conical surface 171 is set to be larger than the diameter of the mounting hole 121 to provide a larger tolerance space, and the worker can insert the magnetron within a larger fluctuation range. The antenna of the magnetron first moves through the first conical surface 143 to the bottom end of the guiding head 17, then contacts the second conical surface 171, enters the middle cavity of the pressing sleeve 14 with a diameter slightly larger than that of the antenna, and finally passes through the first sealing ring 151, the metal ring 152 and the second sealing ring 153. At this time, the bottom surface of the body of the magnetron contacts the first conical surface 143, and the magnetron is fixed on the first conical surface 143 for subsequent vacuum detection operations.

[0060] The following details the specific composition of the helium release mechanism 2 of this embodiment: Combine Figures 7 - 9As shown, a connecting rod 27 is provided at the top of the helium release cover 22, and a through hole 211 is provided on the lifting seat 21. The connecting rod 27 passes through the through hole 211. A limiting block 28 is fixedly provided on the upper part of the connecting rod 27, and the distance between the limiting block 28 and the helium release cover 22 is greater than the length of the through hole 211. Since the distance between the limiting block 28 and the helium release cover 22 is greater than the length of the through hole 211, a moving space of the helium release cover 22 relative to the lifting seat 21 is left. During the working process, the magnetron can be placed on the tooling table 1 directly below the helium release cover 22. The lifting seat 21 is driven by the second lifting cylinder 25 to descend, and the helium release cover 22 covers the corresponding magnetron by its own weight, so as to release helium around the magnetron, cooperate with an additional air extraction mechanism to extract the gas inside the magnetron, and use a helium detection device to detect the extracted gas. If the helium content in the gas exceeds the set value, it is considered that the magnetron has leakage.

[0061] With the above structure, when the helium release cover 22 is blocked by foreign objects during the descending process, the corresponding helium release cover 22 will immediately stop descending, and the helium release cover 22 and the lifting seat 21 will have relative displacement, avoiding accidental injury to the operator's hand by the descending helium release cover 22.

[0062] In order to improve the detection speed and reduce the helium usage, the air inlet end 26 includes an upper air inlet end 261 and a side air inlet end 262. The connecting rod 27 has an air duct 271. One end of the air duct 271 communicates with the top of the inner cavity of the helium release cover 22, and the other end is connected to the upper air inlet end 261. The side air inlet end 262 communicates with the side part of the inner cavity of the helium release cover 22. The helium release cover 22 includes an outer shell 221 and an inner liner 222. The inner liner 222 is arranged in the outer shell 221, and a ventilation gap is provided between the inner liner 222 and the outer shell 221. The top of the inner liner 222 is provided with a first air outlet hole 223, and the lower side is provided with a second air outlet hole 224. The connecting rod 27 is directly connected to the first air outlet hole 223, and the side air inlet end 262 communicates with the ventilation gap. It should be noted that during the detection process, the first air outlet hole 223 directly sprays helium from the top of the magnetron to it. At the same time, the helium introduced from the side air inlet end 262 flows into the ventilation gap and sprays from the second air outlet hole 224 located on the lower side of the inner liner 222 to the lower side of the magnetron, so that the periphery of the magnetron is quickly wrapped by helium. If the magnetron leaks, the detection device can quickly identify it, reducing the detection time and also reducing the helium usage.

[0063] Based on the above design, the helium release cover 22 of this embodiment only abuts against the surface of the tooling for placing the magnetron by its own weight. To maximize the separation of the gases outside and inside the helium release cover 22, a sealing gasket 225 is provided in the bottom area between the outer shell 221 and the inner liner 222. When the helium release cover 22 descends to the in-place position, the sealing gasket 225 contacts the working surface for placing the magnetron.

[0064] Preferably, the lifting seat 21 includes a flat plate portion 212 provided with the through hole 211, and a vertical plate portion 213 vertically extending upward from the edge of the flat plate portion 212. The vertical plate portion 213 is connected to the slider 24. A lifting drive block 214 is provided on the back surface of the vertical plate portion 213. The second lifting cylinder 25 is vertically provided on the tooling table 1, and the piston rod of the second lifting cylinder 25 is connected to the lifting drive block 214.

[0065] It should be noted that designing the lifting seat 21 as a combination of the flat plate portion 212 and the vertical plate portion 213 can install multiple helium release covers 22 on the flat plate portion 212 to drive the helium release covers 22 to lift and lower synchronously. The vertical plate portion 213 is connected to the slider 24. With its larger area, two sets of slide rails 23 with a relatively large distance can be set, and in cooperation with the sliders 24 sliding on the slide rails 23, the lifting seat 21 can lift and lower smoothly. A lifting drive block 214 is provided on the back surface of the vertical plate portion 213. The second lifting cylinder 25 is vertically provided on the tooling table 1, and the piston rod of the second lifting cylinder 25 is connected to the lifting drive block 214, which can make full use of the space between the vertical plate portion 213 and the tooling table 1, avoid interference with the lifting trajectory of the lifting seat 21, and the overall structure is more compact and the structural design is neat and reasonable.

[0066] Preferably, the limiting block 28 is disc-shaped. The disc-shaped limiting block 28 can ensure that the helium release cover 22 can be stably suspended on the flat plate portion 212 and prevent the helium release cover 22 from swinging.

[0067] To improve the detection efficiency, more than two sets of the lifting mounting plates 12 can be arranged side by side on the detection table 11. In this embodiment, five sets of the lifting mounting plates 12 are arranged side by side on the detection table 11. In cooperation with a row of five corresponding helium release covers 22, workers can load five magnetrons onto the corresponding lifting mounting plates 12 at one time and perform the leak detection operation on five magnetrons at one time.

[0068] Combined Figure 10 As shown in the figure, the second embodiment of the present invention proposes a dual-mode leak detection method for magnetrons. Using the dual-mode magnetron leak detector as described above, it includes the following steps:

[0069] S1. Connect the magnetron: Install the magnetron into the lifting mounting plate 12, and extend the antenna of the magnetron into the elastic seal 15; the first lifting cylinder 13 drives the pressing sleeve 14 to descend to compress the elastic seal 15, and the elastic seal 15 seals and connects the antenna with the negative pressure detection tube 16;

[0070] S2. Coarse air inspection: Open the first control valve 34 and the second control valve 35, close the third control valve 36, and the vacuum pump 4 evacuates all the magnetrons installed on the lifting mounting plate 12 through the main pipeline 31 and the branch pipeline 32; after a certain period of time, if the vacuum degree of the vacuum gauge 33 reaches the preset threshold, go to step S4, otherwise go to step S3;

[0071] S3. Fine air inspection: Keep the vacuum pump 4 working and the first control valve 34 open; close the second control valve 35 and the third control valve 36, and then open the second control valve 35 one by one. If the vacuum degree of the vacuum gauge 33 changes when a certain second control valve 35 is opened, mark the corresponding magnetron;

[0072] S4. Preparation of the helium release mechanism: The lifting seat 21 drives the helium release cover 22 to descend, and the helium release cover 22 covers the magnetron;

[0073] S4. Helium leak detection; The helium release cover 22 releases helium to the periphery of the magnetron. Open the third control valve 36, close the first control valve 34, keep the second control valve 35 corresponding to the marked magnetron closed, open the remaining second control valves 35 one by one, and the vacuum pump 4 evacuates the magnetrons installed on the lifting mounting plate 12 through the main pipeline 31 and the branch pipeline 32. The extracted gas passes through the helium detector 5. When the helium passing through the helium detector 5 is less than the preset value, this magnetron is qualified, otherwise it is listed as a non-conforming product together with the magnetrons marked in other steps.

[0074] Among them, the preset threshold of the vacuum gauge 33 in step S2 is 1000 pa - 100 pa; the set vacuum pressure of the vacuum pump 4 in step S4 is 10 pa - 0.1 pa.

[0075] Using the above method, workers can use the above tooling table 1 to fix the antennas of multiple magnetrons and connect them to the dual-mode control gas path 3. The remaining parts of the magnetrons are covered by the helium release hood 22 of the helium release mechanism 2, and helium is released. Then, the vacuum pump 4 evacuates the inside of the magnetrons through the dual-mode control gas path 3. Through the cooperation of two detection modes, rough inspection and fine inspection of the sealing performance of the magnetrons are realized. Among them, by opening the first control valve 34 and closing the third control valve 36, the main pipeline 31 and the branch pipeline 32 are directly connected to the vacuum pump, and the vacuum detector 33 provided on the main pipeline 31 can be used to conduct a rough inspection of the magnetrons. The vacuum degree used in this detection is relatively low, and it can quickly form the required negative pressure detection environment by using the vacuum pump. Moreover, no specific gas is required, the detection efficiency is high, and the cost is low. Magnetrons with relatively large manufacturing defects can be excluded at this stage, such as magnetrons with visible holes or cracks at the joints. Then, by closing the first control valve 34 and opening the third control valve 36, the main pipeline 31 and the branch pipeline 32 are connected to the vacuum pump through the helium detector 5. Whether there is helium outside the magnetrons entering the dual-mode control gas path 3 is detected through the helium detector 5, so as to detect whether there is leakage in the magnetrons. On the one hand, this mode utilizes the strong penetrability of helium, which can easily pass through tiny cracks and holes. On the other hand, by increasing the negative pressure setting value of the vacuum pump 4, the helium outside the magnetrons is more likely to enter the inside of the magnetrons and is finally detected, improving the detection accuracy. To sum up, using the detection equipment and detection method provided in this embodiment can automatically complete the procedures of docking, rough leakage measurement, helium release, and fine leakage measurement of the magnetrons. The detection efficiency is high, the detection process does not require manual intervention, and the degree of automation is high.

[0076] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A magnetron dual-mode leak detector, characterized in that It includes a tooling table, a helium release mechanism, a dual-mode control gas path, a vacuum pump, and a helium detector; The tooling table includes a detection table, a lifting mounting plate, and a positioning and sealing mechanism. A first lifting cylinder is provided on the detection table, and the lifting mounting plate is connected to the first lifting cylinder. The positioning and sealing mechanism includes a pressing sleeve and an elastic seal, and the elastic seal is provided below the pressing sleeve. The helium release mechanism is used to release helium around the magnetron in the helium leak detection mode. The dual-mode control gas path includes a main pipeline and a branch pipeline; the first end of the branch pipeline communicates from the bottom surface of the detection table to the upper surface, the second end of the branch pipeline is connected to the first end of the main pipeline, the second end of the main pipeline is connected to the intake end of the helium detector, and the outlet end of the helium detector is connected to the vacuum pump. The first end of the main pipeline is coiled to form an enclosing frame, and the branch pipeline is connected inside the enclosing frame.

2. The magnetron dual-mode leak detector according to claim 1, characterized in that, A negative pressure detection tube is provided on the detection table, and the negative pressure detection tube is opposite to the pressing sleeve; the elastic seal is provided between the pressing sleeve and the negative pressure detection tube; the first end of the branch pipeline is connected to the negative pressure detection tube.

3. The magnetron dual-mode leak detector according to claim 2, wherein, Adjacent two branch pipelines are arranged in a staggered manner inside the enclosing frame, the first end of the branch pipeline is formed with a bent section, the end of the bent section is communicated with the negative pressure detection tube, and the ends of multiple bent sections are located on the same straight line.

4. The magnetron dual-mode leak detector according to claim 2, wherein, The main pipeline includes a pressure maintaining section, the first end of the pressure maintaining section is connected to the vacuum pump in a switchable manner, the second end of the pressure maintaining section is wound to form the enclosing frame, and a vacuum detector is arranged on the pressure maintaining section.

5. The magnetron dual-mode leak detector according to claim 4, wherein, A first control valve is arranged between the pressure maintaining section and the vacuum pump; the main pipeline further includes a gas detection section, the first end of the gas detection section is connected to the enclosing frame in a switchable manner, the second end of the gas detection section is connected with the helium detector; a second control valve is arranged between each branch pipeline and the negative pressure detection tube; a third control valve is arranged between the first end of the gas detection section and the enclosing frame.

6. The magnetron dual-mode leak detector according to any one of claims 2-5, characterized in that, Each branch pipeline is provided with an elastic damping tube, and the elastic damping tubes are connected through quick connectors.

7. The magnetron dual-mode leak detector according to claim 1, wherein, The helium release mechanism includes a lifting driving mechanism, a lifting seat, and a helium release cover. The lifting driving mechanism includes a slide rail vertically arranged on the tooling table, a slider slidably arranged on the slide rail, and a second lifting cylinder for driving the lifting seat to lift, and the lifting seat is arranged on the slider; the helium release cover is provided with an intake end.

8. The magnetron dual-mode leak detector according to claim 7, characterized in that, An installation hole is provided on the lifting mounting plate, the pressing sleeve is arranged in the installation hole and extends towards the detection table; the negative pressure detection tube is provided with a guiding cavity, a support ring is arranged at the bottom of the guiding cavity, and the elastic seal is supported on the support ring.

9. The magnetron dual-mode leak detector according to claim 8, wherein, The elastic seal includes a first sealing ring, a metal ring, and a second sealing ring arranged in sequence from top to bottom.

10. The magnetron dual-mode leak detector according to claim 8, wherein, The outer wall of the pressing sleeve has a pressure-bearing ring, the upper end of the pressure-bearing ring has a first installation pipe section for extending into the installation hole; the inner wall of the first installation pipe section is provided with a first conical surface; a guiding head is further provided on the lifting mounting plate, and the inner wall of the guiding head is provided with a second conical surface.

11. The magnetron dual-mode leak detector according to claim 1, characterized in that, A connecting rod is provided at the top of the helium release cover, a through hole is provided on the lifting seat, and the connecting rod passes through the through hole; a limiting block is fixedly provided on the upper part of the connecting rod, and the distance between the limiting block and the helium release cover is greater than the length of the through hole.

12. The magnetron dual-mode leak detector according to claim 11, wherein The air inlet end includes an upper air inlet end and a side air inlet end. The connecting rod has an air passage, one end of the air passage communicates with the top of the inner cavity of the helium release cover, and the other end is connected to the upper air inlet end; the side air inlet end communicates with the side part of the inner cavity of the helium release cover.

13. The magnetron dual-mode leak detector according to claim 12, wherein The helium release cover includes an outer shell and an inner liner. The inner liner is arranged in the outer shell, and a ventilation gap is provided between the inner liner and the outer shell; a first air outlet hole is provided at the top of the inner liner, and a second air outlet hole is provided on the lower side surface; the connecting rod is directly connected to the first air outlet hole, and the side air inlet end communicates with the ventilation gap.

14. A method for detecting leaks in a magnetron in dual modes, characterized in that, Using the magnetron dual-mode leak detector as described in claims 1-13, includes the following steps: S1. Connect the magnetron: Install the magnetron on the lifting mounting plate, and the antenna of the magnetron extends into the elastic seal; the first lifting cylinder drives the pressing sleeve to descend to compress the elastic seal, and the elastic seal seals and connects the antenna with the negative pressure detection tube. S2. Rough air inspection: Open the first control valve and the second control valve, close the third control valve, and the vacuum pump evacuates all the magnetrons installed on the lifting mounting plate through the main pipeline and the branch pipeline; after a certain period of time, if the vacuum degree of the vacuum detector reaches the preset threshold, go to step S4, otherwise go to step S3. S3. Fine air inspection: Keep the vacuum pump working and the first control valve open; close the second control valve and the third control valve, and then open the second control valve one by one. If the vacuum degree of the vacuum detector changes when a certain second control valve is opened, mark the corresponding magnetron. S4. Preparation of the helium release mechanism: The lifting seat drives the helium release cover to descend, and the helium release cover covers the magnetron. S4. Helium leak detection; The helium release cover releases helium to the periphery of the magnetron. Open the third control valve, close the first control valve, keep the second control valve corresponding to the marked magnetron closed, open the remaining second control valves one by one, and the vacuum pump evacuates the magnetrons installed on the lifting mounting plate through the main pipeline and the branch pipeline. The extracted gas passes through the helium detector. When the helium passing through the helium detector is less than the preset value, this magnetron is qualified, otherwise it is listed as a non-conforming product together with the magnetrons marked in other steps.

15. The magnetron dual-mode leak detection method according to claim 14, wherein The preset threshold of the vacuum detector in step S2 is 1000 pa - 100 pa; the set vacuum pumping air pressure of the vacuum pump in step S4 is 10 pa - 0.1 pa.

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