Air permeability jig and air tightness detection method thereof

Abstract

The invention discloses an air permeability jig and an air tightness detection method thereof, and relates to the technical field of air permeability detection. The air permeability jig comprises a base table, a positioning assembly, a quick release structure and a sealing assembly, the positioning assembly, the quick release structure and the sealing assembly are arranged on the base table, the positioning assembly comprises a positioning seat and a first positioning block, and the first positioning block is inserted into the positioning seat; the positioning assembly further comprises a second positioning block, and the second positioning block is connected to the positioning base in an inserted mode and used for replacing the first positioning block. The positioning assembly is provided with the replaceable first positioning block and the replaceable second positioning block, different positioning grooves and pipelines are designed to adapt to workpieces of different sizes and shapes, the whole set of positioning assembly does not need to be replaced, the equipment input cost is effectively reduced, and the jig application range is expanded.

Description

Technical Field

[0001] This invention relates to the field of air permeability testing technology, specifically to an air permeability fixture and its airtightness testing method. Background Technology

[0002] In industrial production, many products require air permeability and airtightness testing to ensure that their performance meets usage requirements. As a core testing device, the air permeability fixture's positioning accuracy, assembly / disassembly efficiency, and sealing performance directly affect the accuracy of the test results and the efficiency of the testing process.

[0003] Existing air permeability fixtures have the following shortcomings: First, the positioning components have poor adaptability. Most fixtures have a fixed positioning structure, requiring the replacement of the entire positioning component for different sizes and shapes of workpieces. This not only increases equipment costs but also leads to time-consuming disassembly and assembly, reducing testing efficiency. Second, the disassembly and assembly of fixture components are cumbersome, lacking efficient quick-disassembly structures. Replacing positioning components or maintaining equipment requires the use of various tools, further extending test preparation time. Third, the sealing structure design is unreasonable, and the sealing effect is easily affected by workpiece positioning deviations. Moreover, after long-term use, the seals are prone to aging and failure, leading to gas leakage during testing and affecting the reliability of test data. Fourth, there is a lack of standardized air tightness testing methods adapted to the fixture structure, and the testing process is not standardized, easily leading to deviations in test results due to differences in operation.

[0004] Poor compatibility of positioning components leads to increased equipment costs and reduced testing efficiency; cumbersome disassembly and assembly of fixture components prolongs testing preparation time; and unreasonable sealing structure design makes the sealing effect susceptible to workpiece positioning deviations, affecting the reliability of testing data. Summary of the Invention

[0005] The purpose of this invention is to provide an air permeability fixture and its air tightness testing method to solve the problems mentioned in the background art, such as poor adaptability, low disassembly and assembly efficiency, insufficient sealing performance, and lack of standardized testing methods for existing air permeability fixtures.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an air permeability fixture and its airtightness testing method, comprising a base, a positioning component, a quick-release structure, and a sealing component, wherein the positioning component, the quick-release structure, and the sealing component are disposed on the base, the positioning component comprising a positioning seat and a first positioning block, the first positioning block being inserted into the positioning seat; the positioning component further comprising a second positioning block, the second positioning block being inserted into the positioning seat and used to replace the first positioning block.

[0007] Preferably, the base includes a platform body and a connector. The connector is inserted into the inner side of the platform body. Horizontal bars are provided on both sides of the platform body. Clamping screws are inserted into the horizontal bars. Sliding guide rods are connected to the inner sides of the horizontal bars. The sliding guide rods are located on both sides of the clamping screws. Slider blocks are sleeved on the outer sides of the clamping screws and sliding guide rods. A first air guide pipe is provided inside the platform body. The connector is inserted into the inner side of the first air guide pipe.

[0008] Preferably, the platform body has a sliding groove on its top, an adjusting screw is inserted into the inner side of the sliding groove, a limiting block is sleeved on the outer side of the adjusting screw, and the limiting block is inserted into the inner side of the sliding groove; the platform body also has a slot on its top, the slot is funnel-shaped, a first sealing ring and a second sealing ring are inserted into the inner side of the slot, and the second sealing ring is located above the first sealing ring.

[0009] Preferably, the positioning seat has slots on both sides, a positioning anchor rod is fixedly connected to one side of the positioning seat, a connecting groove is provided on the outer side of the positioning seat, the connecting groove is located in the middle of the positioning anchor rod, a sealing gasket is provided on the inner side of the connecting groove, a plug-in block is fixedly connected to the bottom of the positioning seat, a second air guide pipe is provided on the inner side of the positioning seat, the second air guide pipe passes through the plug-in block and connects to the inner side of the connecting groove, and the second air guide pipe is connected to the first air guide pipe.

[0010] Preferably, a first positioning groove is provided on one side of the first positioning block, a through hole is provided on the inner side of the first positioning groove, a boss is fixedly connected to the outer side of the first positioning groove, a first locking block is connected to the other side of the first positioning block, the first locking block is inserted into the inner side of the connecting groove, the through hole passes through the first locking block and is connected to the second air guide pipe, and an insertion hole corresponding to the positioning anchor rod is provided on the outer side of the first positioning block, the insertion hole is located on the outer side of the first locking block.

[0011] Preferably, a second positioning groove is provided on one side of the second positioning block, the second positioning groove is distributed in a rectangular array, a gas distribution pipe is provided inside the second positioning groove, a second locking block is connected to the other side of the second positioning block, a diversion pipe corresponding to the second gas guide pipe is provided inside the second locking block, and the diversion pipe is connected to the gas distribution pipe.

[0012] Preferably, the quick-release structure includes a positioning rod, a movable rod, and a pull rod. The movable rod is located inside the positioning rod, and the pull rod is located inside the movable rod. A retaining strip is connected to the inner side of one end of the positioning rod, and a first connecting shaft is inserted into the other end of the positioning rod. One end of the movable rod is sleeved on the outer side of the first connecting shaft, and a handle is connected to the inner side of the other end of the movable rod. A positioning insert is inserted into the inner side of the handle, and the positioning insert passes through the positioning rod and the movable rod. One end of the pull rod is sleeved on the outer side of the second connecting shaft, and an insert is sleeved on the other end of the pull rod. The retaining strip is used to engage the slider, and the insert is used to engage the retaining groove.

[0013] Preferably, the sealing assembly includes a hydraulic rod, a sliding member, and a slide rod. The sliding member is connected to the output end of the hydraulic rod, and the slide rod is inserted into the inner side of the sliding member. The outer side of the hydraulic rod is connected to the platform body through a fixing block. A collar is connected to the side of the sliding member near the positioning assembly. Fixed connecting rods are connected to both ends of the slide rod, and the fixed connecting rods are fixedly connected to the top of the platform body.

[0014] Preferably, the sealing assembly further includes a first sealing frame and a sealing plate. The sealing plate is inserted into the inner side of the first sealing frame, and a rod is connected to the outer side of the first sealing frame. The rod is inserted into the inner side of the collar, and a collar is connected to the inner side of the first sealing frame. A second sealing frame is connected to one side of the sealing plate. The second sealing frames are arranged in a rectangular array. A positioning ring is connected to the other side of the sealing plate. The positioning ring is inserted into the inner side of the first sealing frame. The first sealing frame is adapted to the first locking block, and the sealing plate is adapted to the second positioning block.

[0015] Preferably, a method for testing the air tightness of an air permeability fixture includes the following steps: S1: Fixture pretreatment, check the integrity of the first sealing ring, the second sealing ring and the sealing gasket inside the positioning seat on the base to ensure that there is no damage or deformation; connect the connector to the external air pressure testing equipment, calibrate the testing equipment, set the testing pressure range to 0.1-0.3MPa, and the pressure holding time to 30-60s; S2: Positioning component assembly. Based on the size and shape of the workpiece being inspected, select the first positioning block or the second positioning block, insert the first or second locking block into the connecting groove of the positioning seat, and insert the positioning anchor rod into the corresponding insertion hole to achieve pre-positioning. S3: Quick release and fixation. Push the positioning rod of the quick release structure to make the locking strip engage with the slider. Rotate the clamping screw to drive the slider to move along the sliding guide rod until the positioning rod is in contact with the side of the positioning seat. Move the movable rod to rotate around the first connecting shaft to make the pull rod drive the insert to insert into the slot. Insert the positioning insert through the positioning rod to lock the movable rod. S4: Workpiece clamping and sealing. Place the workpiece to be inspected in the first or second positioning groove. Rotate the adjusting screw to drive the limiting block to move along the slide groove until the limiting block fits against the side of the workpiece to achieve limiting. Start the hydraulic rod to push the sliding part to move along the slide rod so that the first sealing frame or sealing plate covers the workpiece inspection area. The first sealing frame fits against the boss, and the second sealing frame is embedded in the second positioning groove. S5: Air tightness test. Gas is introduced into the first air guide pipe through the connector by an external air pressure testing device. The gas enters the sealing cavity formed by the workpiece and the sealing structure through the second air guide pipe and through hole or diversion pipe. When the pressure in the sealing cavity reaches the set value, the air inlet valve is closed and the timer starts. During the pressure holding period, the pressure change is monitored in real time by the testing device. S6: Result judgment and reset. If the pressure drop during the pressure holding period is ≤0.005MPa, the workpiece is judged to be qualified for air tightness; if the pressure drop is >0.005MPa, it is judged to be unqualified. After the test is completed, first release the pressure in the sealing cavity, then reverse the operation to unlock the positioning seat of the quick-release structure, control the hydraulic rod to reset, take out the workpiece, and clean the surface of the positioning component.

[0016] The technical effects and advantages of this invention are as follows: 1. The air permeability fixture and its air tightness testing method are provided with a replaceable first positioning block and a second positioning block in the positioning component. Different positioning grooves and pipeline designs can be used to adapt to workpieces of different sizes and shapes. There is no need to replace the entire positioning component, which effectively reduces equipment investment costs and expands the applicability of the fixture. 2. The air permeability fixture and its air tightness testing method feature a quick-release structure that uses the linkage of a positioning rod, a movable rod, and a pull rod to quickly fix and unlock the positioning seat. The entire process does not require special tools, significantly improving the efficiency of test preparation and equipment maintenance. 3. The air permeability fixture and its air tightness testing method are characterized by a base with double-layer sealing rings, a sealing gasket built into the positioning seat connecting groove, and a sealing assembly equipped with a sealing frame and sealing plate adapted to different positioning blocks, forming a multi-layer sealing structure to effectively prevent gas leakage during the testing process; the funnel-shaped slot design facilitates the installation and positioning of the sealing rings, improving sealing reliability. 4. The air permeability fixture and its air tightness testing method are as follows: the base platform achieves stable movement of the slider through the cooperation of the clamping screw and the sliding guide rod, and the adjusting screw drives the limit block to accurately limit the workpiece; the sealing component adopts hydraulic drive and sliding rod guidance to ensure smooth and accurate sealing action. The overall structure design is reasonable, the operation is convenient, and the skill requirements of the operator are reduced. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the base of the present invention; Figure 3 This is a schematic cross-sectional view of the base structure of the present invention; Figure 4 This is a schematic diagram of the positioning component of the present invention; Figure 5 This is a cross-sectional structural diagram of the positioning seat of the present invention; Figure 6 This is a schematic diagram of the structure of the first positioning block of the present invention; Figure 7 This is a schematic diagram of the structure of the second positioning block of the present invention; Figure 8 This is a cross-sectional structural diagram of the second positioning block of the present invention; Figure 9 This is a schematic diagram of the quick-release component of the present invention; Figure 10 This is a schematic diagram of the sealing assembly of the present invention; Figure 11 This is a schematic diagram of the sealing plate of the present invention.

[0019] In the diagram: 1. Base; 11. Platform; 111. Horizontal bar; 112. Clamping screw; 113. Sliding guide rod; 114. Slider; 115. First air guide pipe; 12. Connector; 13. Slide groove; 131. Adjusting screw; 132. Limiting block; 14. Slot; 141. First sealing ring; 142. Second sealing ring; 2. Positioning assembly; 21. Positioning seat; 211. Slot; 212. Positioning anchor; 213. Connecting groove; 214. Sealing gasket; 215. Insertion block; 216. Second air guide pipe; 22. First positioning block; 221. First positioning groove; 222. Through hole; 223. Boss; 224. Insertion hole; 225. First locking block; 23. Second positioning block; 231. Second positioning groove; 232. Air distribution pipe; 233. Second locking block; 234. Diversion pipe; 3. Quick-release structure; 31. Positioning rod; 311. Locking strip; 312. First connecting shaft; 32. Movable rod; 321. Handle; 322. Positioning insert rod; 323. Second connecting shaft; 33. Pull rod; 331. Insert strip; 4. Sealing assembly; 41. Hydraulic rod; 42. Sliding element; 421. Collar; 43. Slide rod; 431. Fixed connecting rod; 44. First sealing frame; 441. Insert rod; 442. Insert ring; 45. Sealing plate; 451. Second sealing frame; 452. Positioning ring. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention discloses an air permeability fixture and its air tightness testing method, according to the attached... Figures 1-7As shown, it includes a base 1, a positioning component 2, a quick-release structure 3, and a sealing component 4. The positioning component 2, the quick-release structure 3, and the sealing component 4 are disposed on the base 1. The positioning component 2 includes a positioning seat 21 and a first positioning block 22, the first positioning block 22 being inserted into the positioning seat 21. The positioning component 2 also includes a second positioning block 23, the second positioning block 23 being inserted into the positioning seat 21 and used to replace the first positioning block 22.

[0022] According to the appendix Figures 1-3 As shown, the base 1 further includes a platform 11 and a connector 12. The connector 12 is inserted into the inner side of the platform 11. Horizontal bars 111 are provided on both sides of the platform 11. Clamping screws 112 are inserted into the horizontal bars 111. Sliding guide rods 113 are connected to the inner side of the horizontal bars 111. The sliding guide rods 113 are located on both sides of the clamping screws 112. Slider blocks 114 are sleeved on the outer sides of the clamping screws 112 and the sliding guide rods 113. A first air guide pipe 115 is opened on the inner side of the platform 11. The connector 12 is inserted into the inner side of the first air guide pipe 115.

[0023] According to the appendix Figure 3 As shown, further, a sliding groove 13 is provided on the top of the platform 11, an adjusting screw 131 is inserted into the inner side of the sliding groove 13, and a limiting block 132 is sleeved on the outer side of the adjusting screw 131. The limiting block 132 is inserted into the inner side of the sliding groove 13. A slot 14 is also provided on the top of the platform 11. The slot 14 is funnel-shaped, and a first sealing ring 141 and a second sealing ring 142 are inserted into the inner side of the slot 14. The second sealing ring 142 is located above the first sealing ring 141.

[0024] According to the appendix Figures 4-5 As shown, the positioning seat 21 has slots 211 on both sides, a positioning anchor rod 212 is fixedly connected to one side of the positioning seat 21, a connecting groove 213 is provided on the outer side of the positioning seat 21, the connecting groove 213 is located in the middle of the positioning anchor rod 212, a sealing gasket 214 is provided on the inner side of the connecting groove 213, a plug-in block 215 is fixedly connected to the bottom of the positioning seat 21, a second air guide pipe 216 is provided on the inner side of the positioning seat 21, the second air guide pipe 216 passes through the plug-in block 215 and connects to the inner side of the connecting groove 213, and the second air guide pipe 216 is connected to the first air guide pipe 115.

[0025] According to the appendix Figure 9As shown, the quick-release structure 3 includes a positioning rod 31, a movable rod 32, and a pull rod 33. The movable rod 32 is located inside the positioning rod 31, and the pull rod 33 is located inside the movable rod 32. A retaining strip 311 is connected to the inner side of one end of the positioning rod 31, and a first connecting shaft 312 is inserted into the other end of the positioning rod 31. One end of the movable rod 32 is sleeved on the outer side of the first connecting shaft 312, and a handle 321 is connected to the inner side of the other end of the movable rod 32. A positioning insert 322 is inserted into the inner side of the handle 321 and passes through the positioning rod 31. A second connecting shaft 323 is connected to the inner side of the movable rod 32. One end of the pull rod 33 is sleeved on the outer side of the second connecting shaft 323, and an insert 331 is sleeved on the other end of the pull rod 33. The retaining strip 311 is used to engage the slider 114, and the insert 331 is used to engage the slot 211.

[0026] According to the appendix Figure 10 As shown, the sealing assembly 4 includes a hydraulic rod 41, a sliding member 42, and a sliding rod 43. The sliding member 42 is connected to the output end of the hydraulic rod 41, and the sliding rod 43 is inserted into the inner side of the sliding member 42. The outer side of the hydraulic rod 41 is connected to the platform 11 by a fixing block. A collar 421 is connected to the side of the sliding member 42 near the positioning assembly 2. Fixed connecting rods 431 are connected to both ends of the sliding rod 43, and the fixed connecting rods 431 are fixedly connected to the top of the platform 11.

[0027] According to the appendix Figure 11 As shown, it is particularly important to emphasize that the sealing assembly 4 also includes a first sealing frame 44 and a sealing plate 45. The sealing plate 45 is inserted into the inner side of the first sealing frame 44. An insert rod 441 is connected to the outer side of the first sealing frame 44 and is inserted into the inner side of the collar 421. An insert ring 442 is connected to the inner side of the first sealing frame 44. A second sealing frame 451 is connected to one side of the sealing plate 45. The second sealing frames 451 are arranged in a rectangular array. The sealing plate 451 has a vent hole that communicates with the second sealing frame 451. A positioning ring 452 is connected to the other side of the sealing plate 45 and is inserted into the inner side of the first sealing frame 44. The first sealing frame 44 is adapted to the first locking block 225, and the sealing plate 45 is adapted to the second positioning block 23.

[0028] Example 1: According to the appendix Figures 4-6 As shown, it is particularly important to emphasize that the first positioning block 22 has a first positioning groove 221 on one side, a through hole 222 on the inner side of the first positioning groove 221, a boss 223 fixedly connected to the outer side of the first positioning groove 221, and a first locking block 225 connected to the other side of the first positioning block 22. The first locking block 225 is inserted into the inner side of the connecting groove 213, and the through hole 222 passes through the first locking block 225 and is connected to the second air guide pipe 216. The first positioning block 22 has an insertion hole 224 on the outer side corresponding to the positioning anchor rod 212, and the insertion hole 224 is located on the outer side of the first locking block 225.

[0029] Select the first positioning block 22 and insert its first locking block 225 into the connecting groove 213 of the positioning seat 21 to ensure that the positioning anchor rod 212 is inserted into the insertion hole 224; push the positioning rod 31 of the quick release structure 3 so that the locking strip 311 engages with the slider 114; rotate the clamping screw 112 to drive the slider 114 to adjust to the appropriate position; insert the insertion strip 331 into the slot 211; then move the movable rod 32 and insert the positioning insertion rod 322 to lock it.

[0030] Place the workpiece to be tested into the first positioning groove 221, and rotate the adjusting screw 131 to make the limiting block 132 fit against the positioning seat 21; start the hydraulic rod 41 to push the sliding part 42 so that the first sealing frame 44 covers the opening end of the workpiece and fits tightly against the boss 223; connect to the external air pressure testing equipment through the connector 12, introduce 0.2MPa gas, maintain the pressure for 45s, and if the pressure drops to 0.003MPa during the test, the air tightness is deemed qualified; after the test is completed, release the pressure, unlock the quick-release structure 3, and take out the workpiece.

[0031] Example 2: According to the appendix Figures 7-8 As shown, it is particularly important to emphasize that a second positioning groove 231 is provided on one side of the second positioning block 23. The second positioning groove 231 is distributed in a rectangular array. A gas distribution pipe 232 is provided inside the second positioning groove 231. A second locking block 233 is connected to the other side of the second positioning block 23. A diversion pipe 234 corresponding to the second gas guide pipe 216 is provided inside the second locking block 233. The diversion pipe 234 is connected to the gas distribution pipe 232.

[0032] For batch air permeability testing of multiple workpieces, replace with the second positioning block 23, insert the second locking block 233 into the connecting groove 213, and repeat the locking steps of the quick-release structure 3; install the sealing plate 45 so that the positioning ring 452 is inserted into the insertion ring 442 of the first sealing frame 44 to complete the assembly.

[0033] Multiple workpieces are placed into the second positioning groove 231 respectively, and the adjusting screw 131 is rotated to limit the position of the limiting block 132; the hydraulic rod 41 is activated to embed the second sealing frame 451 of the sealing plate 45 into each of the second positioning grooves 231; 0.15MPa gas is introduced and the pressure is maintained for 30s. When the detection pressure drops to 0.002MPa, the airtightness of all workpieces is determined to be qualified; the batch inspection efficiency is many times higher than that of traditional single-station fixtures.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An air permeability fixture, comprising a base (1), a positioning component (2), a quick-release structure (3), and a sealing component (4), wherein the positioning component (2), the quick-release structure (3), and the sealing component (4) are disposed on the base (1), characterized in that, The positioning component (2) includes a positioning seat (21) and a first positioning block (22), the first positioning block (22) being inserted into the positioning seat (21); the positioning component (2) also includes a second positioning block (23), the second positioning block (23) being inserted into the positioning seat (21) and used to replace the first positioning block (22).

2. The air permeability fixture according to claim 1, characterized in that, The base (1) includes a platform (11) and a connector (12). The connector (12) is inserted into the inner side of the platform (11). A horizontal bar (111) is provided on both sides of the platform (11). A clamping screw (112) is inserted into the horizontal bar (111). A sliding guide rod (113) is connected to the inner side of the horizontal bar (111). The sliding guide rod (113) is located on both sides of the clamping screw (112). A slider (114) is sleeved on the outer side of the clamping screw (112) and the sliding guide rod (113). A first air guide pipe (115) is opened on the inner side of the platform (11). The connector (12) is inserted into the inner side of the first air guide pipe (115).

3. The air permeability fixture according to claim 2, characterized in that, The top of the platform (11) is provided with a sliding groove (13), an adjusting screw (131) is inserted into the inner side of the sliding groove (13), a limiting block (132) is sleeved on the outer side of the adjusting screw (131), and the limiting block (132) is inserted into the inner side of the sliding groove (13); the top of the platform (11) is also provided with a slot (14), the slot (14) is configured as a funnel shape, a first sealing ring (141) and a second sealing ring (142) are inserted into the inner side of the slot (14), and the second sealing ring (142) is located above the first sealing ring (141).

4. The air permeability fixture according to claim 2, characterized in that, The positioning seat (21) has slots (211) on both sides. A positioning anchor rod (212) is fixedly connected to one side of the positioning seat (21). A connecting groove (213) is opened on the outer side of the positioning seat (21). The connecting groove (213) is located in the middle of the positioning anchor rod (212). A sealing gasket (214) is provided on the inner side of the connecting groove (213). A plug-in block (215) is fixedly connected to the bottom of the positioning seat (21). A second air guide pipe (216) is opened on the inner side of the positioning seat (21). The second air guide pipe (216) passes through the plug-in block (215) and connects to the inner side of the connecting groove (213). The second air guide pipe (216) is connected to the first air guide pipe (115).

5. The air permeability fixture according to claim 4, characterized in that, The first positioning block (22) has a first positioning groove (221) on one side, and a through hole (222) is provided inside the first positioning groove (221). A boss (223) is fixedly connected to the outside of the first positioning groove (221). A first locking block (225) is connected to the other side of the first positioning block (22). The first locking block (225) is inserted into the inside of the connecting groove (213). The through hole (222) passes through the first locking block (225) and is connected to the second air guide pipe (216). The first positioning block (22) has an insertion hole (224) corresponding to the positioning anchor rod (212) on the outside. The insertion hole (224) is located outside the first locking block (225).

6. The air permeability fixture according to claim 5, characterized in that, The second positioning block (23) has a second positioning groove (231) on one side. The second positioning groove (231) is arranged in a rectangular array. A gas distribution pipe (232) is provided inside the second positioning groove (231). The second positioning block (23) is connected to a second locking block (233) on the other side. A diversion pipe (234) corresponding to the second gas guide pipe (216) is provided inside the second locking block (233). The diversion pipe (234) is connected to the gas distribution pipe (232).

7. The air permeability fixture according to claim 4, characterized in that, The quick-release structure (3) includes a positioning rod (31), a movable rod (32), and a pull rod (33). The movable rod (32) is located inside the positioning rod (31), and the pull rod (33) is located inside the movable rod (32). A retaining strip (311) is connected to the inner side of one end of the positioning rod (31), and a first connecting shaft (312) is inserted into the other end of the positioning rod (31). One end of the movable rod (32) is sleeved on the outside of the first connecting shaft (312), and the other end of the movable rod (32) is connected to the inner side of the first connecting shaft (312). The device has a handle (321), a positioning rod (322) inserted into the inside of the handle (321), the positioning rod (322) passing through the positioning rod (31), and a second connecting shaft (323) connected to the inside of the movable rod (32). One end of the pull rod (33) is sleeved on the outside of the second connecting shaft (323), and the other end of the pull rod (33) is sleeved with a strip (331). The locking strip (311) is used to lock the slider (114), and the strip (331) is used to insert into the slot (211).

8. The air permeability fixture according to claim 1, characterized in that, The sealing assembly (4) includes a hydraulic rod (41), a sliding member (42), and a sliding rod (43). The sliding member (42) is connected to the output end of the hydraulic rod (41), and the sliding rod (43) is inserted into the inner side of the sliding member (42). The outer side of the hydraulic rod (41) is connected to the platform (11) by a fixing block. The sliding member (42) is connected to a collar (421) on the side near the positioning assembly (2). The two ends of the sliding rod (43) are connected to fixed connecting rods (431), and the fixed connecting rods (431) are fixedly connected to the top of the platform (11).

9. The air permeability gauge according to claim 8, characterized in that, The sealing assembly (4) further includes a first sealing frame (44) and a sealing plate (45). The sealing plate (45) is inserted into the inner side of the first sealing frame (44). A plug rod (441) is connected to the outer side of the first sealing frame (44). The plug rod (441) is inserted into the inner side of the collar (421). A plug ring (442) is connected to the inner side of the first sealing frame (44). A second sealing frame (451) is connected to one side of the sealing plate (45). The second sealing frames (451) are arranged in a rectangular array. A positioning ring (452) is connected to the other side of the sealing plate (45). The positioning ring (452) is inserted into the inner side of the first sealing frame (44). The first sealing frame (44) is adapted to the first locking block (225). The sealing plate (45) is adapted to the second positioning block (23).

10. A method for testing the air tightness of an air permeability fixture according to any one of claims 1-9, characterized in that, Includes the following steps: S1: Fixture pretreatment, check the integrity of the first sealing ring (141), the second sealing ring (142) on the base (1) and the sealing gasket (214) in the positioning seat (21) to ensure that there is no damage or deformation; connect the connector (12) to the external air pressure detection equipment, calibrate the detection equipment, set the detection pressure range to 0.1-0.3MPa, and the pressure holding time to 30-60s; S2: Positioning component assembly. According to the size and shape of the workpiece being inspected, select the first positioning block (22) or the second positioning block (23), insert the first locking block (225) or the second locking block (233) into the connecting groove (213) of the positioning seat (21), so that the positioning anchor rod (212) is inserted into the corresponding insertion hole (224) to achieve pre-positioning. S3: Quick release and fixation, push the positioning rod (31) of the quick release structure (3) so that the locking strip (311) is engaged with the slider (114), rotate the clamping screw (112) to drive the slider (114) to move along the sliding guide rod (113) until the positioning rod (31) fits against the side of the positioning seat (21); move the movable rod (32) to rotate around the first connecting shaft (312) so that the pull rod (33) drives the insert (331) to insert into the slot (211), insert the positioning insert (322) through the positioning rod (31) to lock the movable rod (32); S4: Workpiece clamping and sealing: Place the workpiece to be tested in the first positioning groove (221) or the second positioning groove (231), rotate the adjusting screw (131) to drive the limiting block (132) to move along the slide groove (13) until the limiting block (132) fits against the side of the workpiece to achieve limiting; start the hydraulic rod (41) to push the sliding part (42) to move along the slide rod (43) so that the first sealing frame (44) or sealing plate (45) covers the workpiece detection area, the first sealing frame (44) fits against the boss (223), and the second sealing frame (451) is embedded in the second positioning groove (231); S5: Air tightness test. Gas is introduced into the first air guide pipe (115) through the connector (12) by an external air pressure testing device. The gas enters the sealing cavity formed by the workpiece and the sealing structure through the second air guide pipe (216) and the through hole (222) or the diversion pipe (234) and the diversion pipe (232). When the pressure in the sealing cavity reaches the set value, the air inlet valve is closed and the timing starts. During the pressure holding period, the pressure change is monitored in real time by the testing device. S6: Result judgment and reset. If the pressure drop during the pressure holding period is ≤0.005MPa, the workpiece is judged to be qualified for air tightness. If the pressure drop is >0.005MPa, it is judged to be unqualified. After the test is completed, first release the pressure in the sealing cavity, then reverse the operation of the quick-release structure (3) to unlock the positioning seat (21), control the hydraulic rod (41) to reset, take out the workpiece, and clean the surface of the positioning component (2).

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