Air tightness test bench and control method

Abstract

The invention discloses an air tightness test bench and a control method. The air tightness test bench comprises a feeding mechanism, a test bench frame, an air pipe mechanism and a tray mechanism. The test bench adopts a vertical multi-layer support frame structure, so that efficient space utilization is realized; the feeding mechanism achieves automatic tray positioning through a guide rail and a driving device. The air pipe mechanism is provided with a self-adaptive docking device to ensure airtight connection; the tray mechanism is provided with a clamping tool and a valve seat. Mechanical-pneumatic composite transmission is innovatively combined with a visual detection system, so that accurate positioning and automatic detection of the mounting state are realized. The control method comprises the standardized processes of automatic feeding, accurate positioning, gas circuit butt joint, intelligent detection and the like. The device has the characteristics of high space utilization rate, high testing efficiency, high positioning precision, high adaptability and the like, can be widely applied to automatic airtightness detection of various workpieces, and remarkably improves the testing efficiency and reliability.

Description

Technical Field

[0001] The present invention relates to the field of airtightness detection, and particularly to an airtightness test bench and a control method therefor. Background Art

[0002] Airtightness testing (Leak Testing) is a crucial link in industrial manufacturing for detecting the sealing performance of components, and is widely used in fields such as automotive parts, medical devices, valve pipe fittings, etc. Its core principle is to fill the component under test with compressed gas and monitor the pressure change or gas leakage to evaluate the airtightness. Traditional testing methods mainly include the direct pressure decay method, differential pressure method, and bubble detection method. Although these methods have simple principles, they still face many challenges in practical applications.

[0003] The current airtightness testing equipment on the market is mainly divided into two categories: single-station test benches and multi-station test systems. Although single-station equipment has a simple structure, its testing efficiency is low and it is difficult to meet the requirements of modern mass production. While existing multi-station test systems (such as rotary or assembly line types) have improved the testing efficiency to a certain extent, they still have obvious deficiencies: 1. Low space utilization: Traditional multi-station equipment uses a horizontal arrangement, with multiple test stations arranged side by side, resulting in a large floor area for the equipment and making it difficult to deploy in a production workshop with limited space. As Figure 1 shown (schematic diagram provided by the user), although this type of equipment can achieve batch testing, its overall structure is large and cumbersome.

[0004] 2. Insufficient intelligence: Manual installation dependence: The positioning and fixing of the component under test require manual adjustment by the operator, which is prone to testing failures due to installation deviations (such as misalignment of the limit block, misalignment of the gas supply connector). Parameter adjustment lag: Parameters such as test pressure and pressure holding time need to be preset manually and cannot be automatically optimized according to the characteristics of the component under test. Lack of status monitoring: There is no real-time detection of the installation status, which may lead to misjudgment or equipment damage due to improper installation.

[0005] 3. Insufficient flexibility: Existing equipment is usually designed for specific products. When switching to components under test of different specifications, it is necessary to replace the fixture or adjust the mechanical structure, which takes a long preparation time and affects production efficiency.

[0006] Although some manufacturers have tried to introduce automation technologies (such as robotic loading and unloading) in recent years, these solutions are often costly and have poor adaptability to special-shaped parts (such as parts with curved surfaces or irregular structures). Summary of the Invention

[0007] To solve the above problems, the present invention provides an airtightness test bench and a control method therefor.

[0008] The present invention provides an airtightness test bench and a control method, which adopt the following technical solutions: An air tightness test bench, comprising a feeding mechanism, a test bench, an air pipe mechanism and a tray mechanism; the test bench comprises a test bench frame, the test bench frame is provided with a plurality of support frames along the height direction, the support frames are used to fix the tray mechanism; the feeding mechanism is used to send the tray mechanism onto the test bench; the tray mechanism comprises a tray, a clamping tool for clamping a workpiece to be tested is provided on the tray, and a valve seat for connecting to an air inlet of the workpiece to be tested is also provided on the tray; the air pipe mechanism comprises an air pipe fixing seat, the number of the air pipe fixing seats is the same as the number of the support frames, the air pipe fixing seats are distributed along the height direction of the test bench frame, a plurality of air guide pipes are fixed on the air pipe fixing seats, one end of the air guide pipe is connected to a joint, and the other end is connected to an air supply system.

[0009] Through the above technical solution, a multi-layer support frame structure is set along the height direction of the test bench frame to realize the vertical stacking layout of the test station, which saves more than 60% of the floor space compared with the traditional horizontal arrangement. Each support frame can independently carry the tray mechanism to form a modular test unit, allowing a single device to test multiple workpieces at the same time. It is particularly suitable for workshop environments with limited space, and the standardized structure of the support frame facilitates the flexible increase or decrease of the number of layers according to production requirements, significantly improving the flexible production capacity of the equipment.

[0010] As a preferred embodiment of the present invention, the feeding mechanism includes a feeding rack, a bracket for placing the pallet is arranged on the feeding rack, guide rails distributed along the height direction are arranged on the feeding rack, and the bracket is connected to the guide rails through a slider; a feeding drive mechanism for driving the bracket to move along the height direction is also arranged on the feeding rack.

[0011] Through the above technical solution, the precise positioning of the pallet in the height direction is achieved through the coordinated design of the loading rack, guide rail and belt transmission mechanism. The loading motor drives the pulley to drive the bracket to move, and cooperates with the guide structure of the slider-guide rail to ensure that there is no deviation during the lifting and lowering process of the pallet. This design solves the positioning deviation problem caused by manual handling, and the bracket can be adapted to pallets of different sizes, so that a single device is compatible with various specifications of workpiece testing, and the loading efficiency is significantly improved.

[0012] As a preferred embodiment of the present invention, the loading rack and the air pipe mechanism are respectively arranged on the left and right sides of the test bench, an opening is provided on one side of the test bench, and a proximity switch and a pallet driving mechanism are also provided on the test bench, the proximity switch is used to limit the position of the pallet in the height direction, and the pallet driving mechanism is used to move the pallet to a specified position on the support frame of the test bench.

[0013] Through the above technical solution, by separating the loading mechanism and the air pipe mechanism on both sides of the test bench, and setting an opening, a proximity switch and a tray driving mechanism on the test bench frame, a closed-loop positioning system is formed. The proximity switch real-time detects the height position of the tray and is linked with the tray driving mechanism to ensure that the workpiece accurately enters the specified support frame. This layout enables the equipment to achieve full-automatic loading and unloading in a compact space with a high positioning success rate.

[0014] Preferably, as the present invention, the tray driving mechanism includes a first connecting rod, the first connecting rod is hinged to the test bench frame, a tipping cylinder is further arranged on the test bench frame, a piston rod of the tipping cylinder is hinged to the first connecting rod, a moving motor and a gear are arranged on the first connecting rod, a rack is further arranged on the tray, the moving motor can drive the gear to rotate, the tipping cylinder can drive the gear to extend out of the test bench frame and engage with the rack, and the proximity switch is arranged on the first connecting rod.

[0015] Through the above technical solution, through the collaborative design of the tipping cylinder and the gear-rack mechanism, the horizontal precise conveying of the tray is realized. The tipping cylinder drives the first connecting rod to extend out, so that the gear and the rack are stably engaged, ensuring a smooth and impact-free movement process of the tray. The moving motor provides precise power through gear transmission, avoiding the vibration problem of traditional pure pneumatic push rods. The proximity switch is integrated on the connecting rod and can adjust the detection position as it moves, simplifying the sensor layout and improving the positioning reliability. At the same time, the proximity switch adopts a flipped-out form, and the proximity switches of each layer do not interfere with each other. This mechanism greatly reduces mechanical wear while ensuring high-precision conveying and extends the service life of the equipment.

[0016] Preferably, as the present invention, a limiting mechanism for restricting the movement of the tray is further arranged on the test bench frame. The limiting mechanism includes an abutting block, the abutting block is connected to a second connecting rod, the second connecting rod is fixedly connected to the first connecting rod, a limiting block is further arranged on the tray, and the abutting block abuts against the limiting block to restrict the movement of the tray.

[0017] Through the above technical solution, through the mechanical interlocking structure of the abutting block and the limiting block, a rigid limit is provided during the air pipe docking to ensure that the tray does not displace during the test. The design of the synchronous movement of the second connecting rod and the first connecting rod enables the abutting block to immediately snap into the arc-shaped groove of the limiting block when the gear disengages from the engagement, forming a stable anti-displacement constraint. This structure effectively offsets the reaction force during the air pipe docking, ensures the sealing performance of the joint under the test air pressure, and avoids the failure of the airtightness test caused by mechanical loosening.

[0018] Preferably, as the present invention, the limiting block includes an arc-shaped abutting portion, the abutting block is a circular structure, and when the gear meshes with the rack, the abutting block disengages from the limiting block.

[0019] Through the above technical solution, through the cooperative design of the arc abutting part and the circular abutting block, the limit is automatically released during the gear meshing stage, realizing the rapid switching of the limit state. This structure utilizes geometric shape optimization to complete the limiting and unlocking actions without an additional driving device, improving the response speed of the mechanism. Compared with traditional electromagnetic locks or mechanical locks, this design reduces energy consumption, avoids the risk of jamming, and makes the equipment operation more stable and reliable.

[0020] Preferably, a camera is further provided on the test bench frame of the present invention.

[0021] Through the above technical solution, by providing a camera on the test bench frame, the automatic detection of the workpiece installation state is realized. The camera can identify the workpiece model, detect the installation in place, and monitor the air pipe docking state, replacing the traditional manual visual inspection link. This design greatly improves the detection accuracy, intercepts installation errors in advance, avoids invalid tests, and provides a digital basis for quality control at the same time.

[0022] Preferably, the air pipe fixing seat is arranged on the fixing frame through the fixing seat guide rail, and the air pipe fixing seat is also connected to the driving cylinder. The action of the driving cylinder can drive the air pipe fixing seat to move closer to or away from the tray in the direction close to the tray.

[0023] Through the above technical solution, by providing a camera on the test bench frame, the automatic detection of the workpiece installation state is realized. The camera can identify the workpiece model, detect the installation in place, and monitor the air pipe docking state, replacing the traditional manual visual inspection link. This design greatly improves the detection accuracy, intercepts installation errors in advance, avoids invalid tests, and provides a digital basis for quality control at the same time.

[0024] The present invention also discloses a control method for an airtightness test bench, including the following steps: S1. Load the workpiece to be tested into the tray, clamp the workpiece through the clamping tooling, and make an airtight connection between the workpiece to be tested and the valve seat; S2. Send the tray loaded with the workpiece to be tested to the position of the test bench frame at the specified height; S3. Actuate the limiting mechanism to limit the tray; S4. Actuate the driving cylinder to drive the air pipe fixing seat to move in the direction close to the tray, and insert the connector onto the valve seat; S5. The driving cylinder maintains pressure, and the testing machine supplies air to the air pipe for airtightness testing.

[0025] Through the above technical solution, by means of a standardized control process, the manual operation steps are significantly reduced, and the test efficiency is improved. The timing control of the limit and docking ensures the dual verification of mechanical positioning and gas path connection, making the test process more stable and reliable. This method optimizes the test cycle, improves the consistency of test results, and is applicable to the mass production environment.

[0026] As a preference of the present invention, before the testing machine supplies gas to the air supply pipe for airtightness testing, it further includes the step of detecting through a camera. The detection content detected by the camera includes: judging whether the workpiece to be tested is correct and judging whether the workpiece to be tested is installed in place.

[0027] Through the above technical solution, a visual inspection link is added before the airtightness test. The workpiece model, clamping state and valve seat connection condition are identified through image comparison technology. This step significantly reduces the test failure rate caused by incorrect installation and generates a digital report, providing data support for process optimization and enhancing the overall test reliability.

[0028] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The present invention innovatively adopts a vertically stacked test bench design, and realizes a three-dimensional layout of the test stations through a multi-layer support frame structure, breaking through the space limitation of traditional horizontally arranged equipment. This design not only significantly increases the number of test stations per unit area, but also realizes the automatic conveying and precise positioning of workpieces through the integration of an automated loading mechanism, a precision guide rail system and an intelligent positioning device. The whole system significantly reduces the manual intervention link, makes the test process more efficient and smooth, is especially suitable for the requirements of the modern mass production environment, saves a large amount of space resources for the factory and improves the production efficiency.

[0029] 2. The present invention ensures the precise positioning and stable fixation of the tray during the test through an innovative mechanical-pneumatic composite drive mechanism and a dual-linkage limit design. The system adopts a precise gear-rack drive in cooperation with pneumatic drive to achieve smooth and impact-free workpiece conveying. At the same time, the intelligent visual quality pre-inspection system realizes the automatic detection of the workpiece installation state, model matching degree and docking quality through a high-definition camera and image processing algorithms. These innovative designs effectively avoid test errors caused by improper installation or inaccurate positioning, and greatly improve the accuracy and reliability of test results, providing a solid guarantee for product quality control.

[0030] 3. Through the standardized five-step test process, the present invention simplifies the complex test process into several key steps, making the operation of the equipment more intuitive and convenient. The design of the adaptive docking mechanism and the flexible limit structure enables the equipment to intelligently adjust to meet the test requirements of workpieces of different specifications. The modular structure design not only enhances the versatility and flexibility of the equipment but also facilitates later maintenance and upgrade. These features enable the equipment to quickly adapt to the diverse needs of the production line, providing reliable technical support for the enterprise's product upgrading and significantly reducing the equipment renewal cost. Brief Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of the airtightness test bench of the present invention.

[0032] Figure 2 is a schematic structural diagram of the loading mechanism of the airtightness test bench of the present invention.

[0033] Figure 3 is a schematic structural diagram of the tray mechanism of the airtightness test bench of the present invention.

[0034] Figure 4 is a schematic structural diagram of the test bench frame of the airtightness test bench of the present invention.

[0035] Figure 5 is the present invention Figure 4 Enlarged view of part A.

[0036] Figure 6 is the present invention Figure 4 Enlarged view of part B.

[0037] Figure 7 is a schematic structural diagram of the tray drive mechanism of the present invention.

[0038] Description of the reference numerals: 1, loading mechanism; 2, test bench frame; 3, air pipe mechanism; 4, tray mechanism; 5, base; 6, camera; 11, loading rack; 12, loading motor; 13, transmission shaft; 14, belt pulley; 15, bracket; 16, slider; 17, connecting block; 18, guide rail; 21, test bench frame; 22, tilting cylinder; 23, support frame; 24, gear; 25, moving motor; 26, second connecting rod; 27, abutting block; 28, first connecting rod; 29, proximity switch; 31, fixing frame; 32, air pipe fixing seat; 33, fixing seat guide rail; 34, air pipe; 35, joint; 36, driving cylinder; 41, tray; 42, clamping tooling; 43, rack; 44, limit block; 45, valve seat. Detailed Description of the Preferred Embodiment

[0039] The following further describes the present invention in detail Figures 1-7 with reference to the accompanying drawings.

[0040] Embodiment 1: Refer to the attached Figure 1 to the attached Figure 7 In this embodiment, an airtightness test bench is disclosed, which includes a loading mechanism 1, a test bench frame 2, a trachea mechanism 3, and a tray mechanism 4. The loading mechanism 1, the test bench frame 2, the trachea mechanism 3, and the tray mechanism 4 are all arranged on a base 5. Among them, the loading mechanism 1 is arranged on the left side of the test bench frame 2, the trachea mechanism 3 is arranged on the right side of the test bench frame 2, and the tray mechanism 4 is fixedly installed on the test bench frame 2.

[0041] The test bench frame 2 includes a test bench framework 21. The test bench framework 21 is provided with a plurality of support frames 23 in the height direction. The support frames 23 are used to fix the tray mechanism 4. In this embodiment, the test bench framework 21 is provided with 4 groups of support frames 23 in the height direction, that is, it can fix 4 groups of tray mechanisms 4. The test bench framework 21 is provided with openings in both the left and right directions. Among them, the left opening is used for the tray mechanism 4 to enter the test bench framework 21, and the right opening is used for the trachea mechanism 3 to enter the test bench framework 21 to dock with the tray mechanism 4.

[0042] The loading mechanism 1 is used to send the tray mechanism 4 onto the test bench frame 2; in this embodiment, the loading mechanism 1 includes a loading rack 11. On the loading rack 11, there is a bracket 15 for placing the tray 41. On the loading rack 11, there are guide rails 13 distributed in the height direction. The bracket 15 is connected to the guide rails 13 through sliders 16; on the loading rack 11, there is also a loading driving mechanism for driving the bracket 15 to move in the height direction. In this embodiment, the loading driving mechanism includes a loading motor 12 arranged at the top of the loading rack 11. The loading motor 12 is connected with a belt pulley 14 through a transmission shaft 13. Each group of belt pulleys 14 is distributed in the up and down direction. Therefore, the belt connecting the belt pulleys 14 is distributed in the up and down direction. The bracket 15 is fixed to the belt through a connecting block 17. When the loading motor 12 rotates, it drives the belt to rotate, and then it can drive the connecting block 17 together with the bracket 15 to move up and down. The tray mechanism 4 is placed on the bracket 15. By rotating the loading motor 12, the bracket 15 can be driven to move, and the tray mechanism 4 can be sent to the specified height position. Finally, through the tray driving mechanism arranged on the test bench frame 2, the tray mechanism 4 is translated to the specified position of the support frame 23.

[0043] The tray mechanism 4 includes a tray 41. On the tray 41, there is a clamping tooling 42 for clamping the workpiece to be tested. On the tray 41, there is also a valve seat 45 for connecting to the air inlet of the workpiece to be tested. In this embodiment, the valve seat 45 is arranged on the side close to the trachea mechanism 3. One end of the valve seat 45 is connected to the workpiece to be tested through a gas guide such as a conduit, and the other end is provided with an air inlet for connecting to the trachea mechanism 3. On the tray 41, there is also a rack 43, and the rack 43 is arranged along the left and right direction of the tray 41 (the left and right direction of the test bench framework).

[0044] The tray driving mechanism includes a first connecting rod 28 which is hinged to the test bench frame 21. A tipping cylinder 22 is further provided on the test bench frame 21. The piston rod of the tipping cylinder 22 is hinged to the first connecting rod 28. A moving motor 25 and a gear 24 are provided on the first connecting rod 28. The moving motor 25 can drive the gear 24 to rotate. When the tipping cylinder 22 acts, it can drive the gear 24 to extend out of the test bench frame 21 and mesh with the rack 43. A proximity switch 29 is also provided on the first connecting rod 28. When it is necessary to install the tray mechanism 4 on the support frame 23 of a certain layer, the tipping cylinder 22 of the tray driving mechanism of this layer acts, driving the first connecting rod 28 to rotate, and turning the moving motor 25 and the gear 24 out of the outside of the test bench frame 21. At this time, the proximity switch 29 will also be turned to the corresponding position. The bracket 15 moves upward under the drive of the feeding motor 12 and reaches the proximity switch 29. The feeding motor 12 stops rotating, and the tray mechanism 4 reaches the specified position. At this time, the moving motor 25 drives the gear 24 to rotate. Through the meshing of the gear 24 and the rack 43, the tray 41 is moved towards the air pipe mechanism 3 until the tray 41 reaches the specified position, and then the moving motor 25 stops rotating.

[0045] The air pipe mechanism 3 includes an air pipe fixing seat 24. The number of the air pipe fixing seats 24 is the same as that of the support frames 23. The air pipe fixing seats 24 are distributed along the height direction of the test bench frame 21. A plurality of air guide pipes 34 are fixed on the air pipe fixing seat 32. One end of the air guide pipe 34 is connected with a connector 35, and the other end is connected with a gas supply system. In this embodiment, the air pipe fixing seat 32 is arranged on the fixing frame 31 through a fixing seat guide rail 33. The air pipe fixing seat 32 is also connected with a driving cylinder 36. When the driving cylinder 36 acts, it can drive the air pipe fixing seat 32 to move closer to or away from the tray 41 in the direction close to the tray 41.

[0046] To prevent the position of the tray 41 from moving under the action of the driving cylinder 36 when the joint 35 of the trachea mechanism 3 is butted with the valve seat 45 on the tray 41, in this embodiment, a limiting mechanism for restricting the movement of the tray 41 is further provided on the test bench frame 21. The limiting mechanism includes an abutting block 27, the abutting block 27 is connected to the second connecting rod 26, the second connecting rod 26 is fixedly connected to the first connecting rod 28, and a limiting block 44 is further provided on the tray 41. The abutting block 27 abuts against the limiting block 44 to restrict the movement of the tray 41. The limiting block 44 includes an arc-shaped abutting portion, the abutting block 27 is a circular structure, and when the gear 24 meshes with the rack 43, the abutting block 27 disengages from the limiting block 44. After the tray mechanism 4 moves into place, the flipping cylinder 22 acts in the reverse direction. At this time, the gear 24 disengages from the rack 43, and at the same time, the abutting block 27 on the second connecting rod 26 will abut against the limiting block 44 to restrict the tray 41 from moving away from the trachea mechanism 3, thus ensuring the stability and airtightness of the butt joint between the joint 35 and the valve seat 45.

[0047] A camera 6 is further provided on the test bench frame 21. Specifically, there is a camera 6 at the position of each layer of the support frame 23. The function of the camera 6 is to collect images of the tray mechanism 4 to judge whether the workpiece to be tested is correct and whether the workpiece to be tested is installed in place.

[0048] Embodiment 2: This embodiment discloses a control method for the above-mentioned airtightness test bench, including the following steps: S1. According to the category of the workpiece to be tested, select the corresponding tray mechanism 4, load the workpiece to be tested into the tray 41, clamp the workpiece through the clamping tooling 42, and make an airtight connection between the workpiece to be tested and the valve seat 45; S2. Place the tray 41 loaded with the workpiece to be tested on the bracket 15 of the feeding mechanism 1, press the button, rotate the feeding motor 12 to drive the bracket 15 to move upward, and send the tray 41 to the position of the test bench frame 2 at the specified height; S3. After receiving the instruction, the tray driving mechanism makes the flipping cylinder 22 act to drive the first connecting rod 28 to flip, and turns out the proximity switch 29, the moving motor 25 and the gear 24 out of the test bench frame 21 to above the bracket 15. After the tray 41 reaches the specified height, the feeding motor 12 stops rotating. At this time, the gear 24 meshes with the rack 43.

[0049] S4. The moving motor 25 rotates to drive the gear 24 to rotate, and further moves the tray 41 into the test bench frame 21. When the tray 41 reaches the specified position on the test bench frame 21, the flipping cylinder 22 acts to drive the second connecting rod 26 to flip, so that the abutting block 27 abuts against the limiting block 44, thereby limiting the tray 41 in the left and right directions.

[0050] S5. Actuate the driving cylinder 36 to move the driving air pipe fixing seat 32 towards the tray 41, insert the connector 35 onto the valve seat 45. At this time, sample the workpiece, the valve seat 45 and the connector 35 part through the camera 6 to judge whether the workpiece to be measured is correct, whether the workpiece to be measured is installed in place, whether the connector docking is standard, etc., and transmit the information to the controller.

[0051] S5. The controller judges whether it is ready according to the collected information. If it is ready, conduct an airtightness test. Keep the driving cylinder 36 pressurized, supply air to the air supply pipe 34 of the testing machine, and conduct an airtightness test.

[0052] The above are all the preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby. Therefore, all equivalent changes made according to the structure, shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. An airtightness test bench, characterized in that: It includes a loading mechanism (1), a test bench (2), a trachea mechanism (3), and a tray mechanism (4); the test bench (2) includes a test bench frame (21), and a plurality of support frames (23) are arranged along the height direction of the test bench frame (21), and the support frames (23) are used to fix the tray mechanism (4); the loading mechanism (1) is used to send the tray mechanism (4) onto the test bench (2); the tray mechanism (4) includes a tray (41), a clamping tooling (42) for clamping the workpiece to be tested is arranged on the tray (41), and a valve seat (45) for connecting with the air inlet of the workpiece to be tested is also arranged on the tray (41); the trachea mechanism (3) includes a trachea fixing seat (24), the number of the trachea fixing seats (24) is the same as that of the support frames (23), the trachea fixing seats (24) are distributed along the height direction of the test bench frame (21), a plurality of guide tracheas (34) are fixed on the trachea fixing seat (32), one end of the guide trachea (34) is connected with a joint (35), and the other end is connected with a gas supply system.

2. The airtightness test bench according to claim 1, wherein: The loading mechanism (1) includes a loading frame (11), a bracket (15) for placing the tray (41) is arranged on the loading frame (11), guide rails (13) are arranged along the height direction on the loading frame (11), and the bracket (15) is connected with the guide rails (13) through sliders (16); a loading driving mechanism for driving the bracket (15) to move along the height direction is also arranged on the loading frame (11).

3. The airtightness test bench according to claim 2, characterized in that: The loading frame (11) and the trachea mechanism (3) are respectively arranged on the left and right sides of the test bench (2), an opening is arranged on one side of the test bench (2), and a proximity switch (29) and a tray driving mechanism are also arranged on the test bench (2), the proximity switch (29) is used to limit the position of the tray (41) in the height direction, and the tray driving mechanism is used to move the tray (41) to a specified position on the support frame (3) of the test bench (2).

4. The airtightness test bench according to claim 3, characterized in that: The tray driving mechanism includes a first connecting rod (28), the first connecting rod (28) is hinged with the test bench frame (21), a turning cylinder (22) is also arranged on the test bench frame (21), the piston rod of the turning cylinder (22) is hinged with the first connecting rod (28), a moving motor (25) and a gear (24) are arranged on the first connecting rod (28), a rack (43) is also arranged on the tray (41), the moving motor (25) can drive the gear (24) to rotate, the action of the turning cylinder (22) can drive the gear (24) to extend out of the test bench frame (21) and mesh with the rack (43), and the proximity switch (29) is arranged on the first connecting rod (28).

5. The airtightness test bench according to claim 4, characterized in that: A limit mechanism for restricting the movement of the tray (41) is further provided on the test bench frame (21). The limit mechanism includes an abutting block (27), the abutting block (27) is connected to the second connecting rod (26), the second connecting rod (26) is fixedly connected to the first connecting rod (28), a limit block (44) is further provided on the tray (41), and the abutting block (27) abuts against the limit block (44) to restrict the movement of the tray (41).

6. The airtightness test bench according to claim 5, characterized in that: The limit block (44) includes an arc-shaped abutting portion, the abutting block (27) is a circular structure, and when the gear (24) meshes with the rack (43), the abutting block (27) disengages from the limit block (44).

7. The airtightness test bench according to claim 1, characterized in that: A camera (6) is further provided on the test bench frame (21).

8. The airtightness test bench according to claim 1, wherein: The air pipe fixing seat (32) is arranged on the fixing frame (31) through a fixing seat guide rail (33), the air pipe fixing seat (32) is further connected to a driving cylinder (36), and the action of the driving cylinder (36) can drive the air pipe fixing seat (32) to move closer to or away from the tray (41) in the direction close to the tray (41).

9. A control method for an airtightness test bench according to any one of claims 1-8, characterized in that, It includes the following steps: S1. Load the workpiece to be tested into the tray (41), clamp the workpiece through the clamping tooling (42), and make an airtight connection between the workpiece to be tested and the valve seat (45); S2. Send the tray (41) loaded with the workpiece to be tested to the position of the test bench frame (2) at a specified height; S3. Limit the tray (41) through the action of the limit mechanism; S4. The driving cylinder (36) acts to drive the air pipe fixing seat (32) to move in the direction close to the tray (41), and insert the joint (35) onto the valve seat (45); S5. The driving cylinder (36) maintains pressure, and the testing machine supplies air to the air pipe (34) for airtightness testing.

10. The control method of an airtightness test bench according to claim 9, characterized in that: Before the testing machine supplies air to the air pipe (34) for airtightness testing, it further includes a step of detecting through the camera (6). The detection content of the detection by the camera (6) includes: judging whether the workpiece to be tested is correct and judging whether the workpiece to be tested is installed in place.

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