Sealing device for air tightness detection of automobile parts

Abstract

The application provides a sealing device for air tightness detection of automobile accessories, and relates to the technical field of air tightness detection of automobile accessories.The sealing device comprises a base assembly, which serves as a bearing base of the device and comprises a base and an electric control system.T-shaped sliding rails are formed in the base, each group of the sliding rails is provided with 2-4 slidable connecting sliding blocks, and the top of each connecting sliding block is provided with a quick locking mechanism.The combination of the detachable sealing unit, the displacement adjusting mechanism and the replaceable positioning pin enables a set of device to be suitable for sealing openings of automobile accessories with different diameters and shapes, the mold replacement time is shorter, the mold cost is reduced, the servo motor and the ball screw of the displacement adjusting mechanism are combined to realize the positioning accuracy of the sealing head, which is much higher than the positioning accuracy of the traditional manual adjustment, the accuracy of the sealing position is ensured, the sealing failure caused by the positioning deviation is reduced, and the problems of poor adaptability and low sealing pressure control accuracy are solved.

Description

Technical Field

[0001] This invention belongs to the field of automotive parts airtightness testing technology, specifically relating to a sealing device for airtightness testing of automotive parts. Background Technology

[0002] In the automotive manufacturing industry, air tightness is one of the key indicators for measuring the quality of automotive parts. Failure to meet air tightness standards can lead to serious malfunctions such as engine oil leaks, water ingress into the transmission, and brake failure. Therefore, strict air tightness testing must be conducted before the parts leave the factory. Existing sealing devices for airtightness testing suffer from the following technical bottlenecks: First, poor adaptability. Traditional sealing devices are mostly fixed molds designed for specific parts. When testing parts of different models or specifications, such as engine blocks of different displacements or gearbox housings of different sizes, the entire sealing mold needs to be replaced. This results in high mold manufacturing costs and long replacement times, making it unsuitable for flexible production needs involving multiple varieties and small batches. Second, low precision in sealing pressure control. Existing devices mostly use manual adjustment of pressure reducing valves to control sealing pressure, leading to large pressure fluctuations. Furthermore, they cannot adaptively adjust the pressure according to the surface morphology of the parts, causing some areas to be too tight, resulting in part deformation, while other areas are too loose, leading to leakage. This results in a certain rate of false detection. Third, low automation. The positioning, pressure adjustment, and judgment of test results of the sealing device largely rely on manual operation. This involves high labor intensity, and human factors can easily lead to unstable test results and poor consistency during batch testing. Fourth, insufficient multi-channel synchronous testing capability. Most devices can only test 1-2 parts at a time. When facing the batch testing needs of the production line, the testing efficiency is low and cannot match the production line cycle, resulting in production bottlenecks. Summary of the Invention

[0003] The purpose of this invention is to overcome the defects of existing sealing devices for airtightness testing of automotive parts, and to provide a sealing device for airtightness testing of automotive parts.

[0004] The first aspect of this disclosure provides a sealing device for airtightness testing of automotive parts, specifically including: a base assembly, a sealing unit, a fixing ring, a pressure regulating clamp, a connecting slider, a displacement adjusting mechanism, and a vacuum and air pressure supply system; the base assembly, serving as the supporting foundation of the device, is formed by welding steel plates. The base assembly includes a base platform and an electrical control system. T-shaped slide rails are provided on the base platform, with 3-6 sets of slide rails evenly distributed along the length of the base platform. Each set of slide rails has 2-4 slidable connecting sliders. The top of the connecting sliders is provided with a quick-locking mechanism, which uses pneumatic locking. After locking, the positioning accuracy is ±0.1mm, used to fix the sealing unit. A part positioning platform is provided in the middle of the top surface of the base platform. A detachable positioning pin is installed on the positioning platform. The positioning pin of the corresponding size can be replaced according to the positioning hole specifications of different parts to ensure accurate positioning of the parts. The interior of the base platform has reserved pipeline channels and cable trays for arranging pipelines and electrical control circuits of the vacuum and air pressure system, avoiding pipeline wear or circuit aging caused by external interference.

[0005] More preferably, the bottom of the sealing unit is snapped onto the guide rail, and the outer bottom plate of the guide rail is fastened to the connecting slider by bolts. The bottom of the guide rail is provided with a positioning hole, which cooperates with the positioning pin on the top of the connecting slider to achieve initial positioning, and then is locked by a quick locking mechanism. The sealing unit is equipped with a fixing ring, a pressure regulating clamp, a proportional valve and a fixing frame. The bottom of the sealing unit is provided with a support frame, and a motor is installed inside the support frame. The inner end face of the sealing unit is provided with an air inlet. The top of the sealing unit is connected to the electrical control system through a pipeline. The inner end face of the sealing unit has three layers of sealing ports. The corresponding sealing head contour is designed according to the shape of the sealing port of the accessory. An elastic sealing ring is embedded in the outer ring of the sealing port. The material is fluororubber, which is temperature resistant from -20℃ to 200℃ to meet the compatibility requirements of the detection medium. The compression of the sealing ring can be controlled at 10%-20% by subsequent pressure adjustment to ensure the sealing effect while avoiding accelerated aging caused by excessive compression.

[0006] More preferably, the fixing ring is an annular component, with an annular groove on the outer circumference of the fixing ring. Coaxial annular bars are respectively provided on both sides of the inner wall of the groove. A rotating ring is engaged in the groove. A fixing frame is fixedly connected to the inner end face of the fixing ring. A sleeve with threads on the inner wall is rotatably installed at the end of the fixing frame. A helical gear is fixedly provided on the outside of the sleeve. When the helical gear is rotated, it drives the sleeve to rotate synchronously, realizing synchronous transmission. The annular bars are used to form a radial limit for the rotating ring embedded in the groove, without affecting the rotation of the rotating ring.

[0007] More preferably, the pressure regulating clamp includes a motor, a rotating ring, and a moving rod. The motor is installed inside the support frame, and a spur gear is coaxially connected to the motor's drive shaft. The outer edge of the rotating ring has teeth that mesh with the spur gear. A helical gear ring is provided on the outer side of the inner end face of the rotating ring, and the helical gear ring meshes with a helical gear on the outside of the sleeve. The outer wall of the moving rod has threads that mesh with the sleeve. A clamping plate is fixedly connected to the inner end of the moving rod, and the clamping plate is engaged in a groove inside the sealing unit. The motor is electrically connected to the electrical control system. After the motor is started by the controlled end, it drives the spur gear to rotate through the drive shaft. The rotating ring rotates through the meshing with the helical gear ring. The rotating ring rotates the sleeve through the meshing with the helical gear. The threads on the inner wall of the sleeve drive the moving rod to move, thereby moving the clamping plate to achieve clamping and fixing of the accessories.

[0008] More preferably, a quick-locking mechanism is provided on the top of the connecting slider, and a locking block is provided on the top of the quick-locking mechanism. The quick-locking mechanism is electrically connected to the control terminal inside the electronic control system. The locking block is pneumatically locked to the guide rail. A T-shaped groove is opened at the bottom of the connecting slider, and a T-shaped slide rail is engaged inside the T-shaped groove. Distance sensors are installed on the opposite faces of two corresponding connecting sliders. The distance sensors are electrically connected to the electronic control system. When the electric drive moving module inside the connecting slider is activated by the control terminal and moves on the T-shaped slide rail, the position of the connecting slider is adjusted, and the left and right positions are fixed after positioning.

[0009] More preferably, the displacement adjustment mechanism consists of a servo motor, a ball screw, and a guide rail mounted on the top of the rear support frame. The servo motor is connected to the ball screw via a coupling. The bottom of the nut of the ball screw is fixedly connected to the top surface of the rear sealing unit. One end of the ball screw is connected to the drive shaft of the servo motor, and the other end is rotatably connected to a right-angle plate connected to the top surface of the front support frame. A probe is provided on the outer end face of the support frame. The probe and the rangefinders on the front and rear sides of the top of the base are on the same horizontal line. After the support frame moves back and forth, the distance can be accurately measured by the rangefinder, so that the front and rear directions can be accurately positioned. The servo motor drives the screw to rotate, and the nut drives the rear sealing unit to move along the guide rail, so as to realize the axial positioning of the sealing unit and the sealing port of the accessory. The displacement signal is fed back to the electronic control system in real time through the encoder built into the motor. The proportional valve is electrically connected to the electronic control system, and the sealing pressure is controlled by adjusting the air pressure.

[0010] More preferably, the sealing unit is internally equipped with a proportional valve, a pressure relief valve, a pressure sensor, a pneumatically controlled check valve, and connecting pipelines. The inlet of the proportional valve is connected to the vacuum and pneumatic supply system inside the electronic control system, and the outlet is connected to the inlet of each sealing unit through branch pipelines. Each branch pipeline is equipped with a pneumatically controlled check valve to maintain stable sealing pressure. The signal output of the pressure sensor is connected to the electronic control system through a shielded cable to transmit the detected sealing pressure signal to the electronic control system in real time. When the electronic control system detects that the sealing pressure is lower than the set value, it outputs a signal to control the proportional valve to increase the opening to supplement the air pressure. When the pressure is higher than the set value, it controls the pressure relief valve to open and release pressure, forming a pressure closed-loop control to ensure that the sealing pressure fluctuation range is controllable and stable. In addition, the pressure regulation system is also equipped with a pressure alarm threshold. When the pressure exceeds the threshold, the electronic control system issues an alarm signal and stops the detection process.

[0011] More preferably, the vacuum and air pressure supply system provides the sealing unit with the compressed air or vacuum required for testing, including an air compressor, a vacuum generator, an air tank, a dryer filter, a shut-off valve, and pipelines. The air compressor's outlet is sequentially connected to the dryer filter and the air tank to remove moisture and impurities from the compressed air, preventing any impact on the sealing effect or damage to the valves. The air tank's outlet is divided into two paths: one path connects to the proportional valve inlet of the pressure regulating system via a shut-off valve to provide sealing pressure to the sealing unit; the other path connects to the vacuum generator's inlet via a shut-off valve. The vacuum generator's vacuum end is connected to the testing unit via pipelines. The vacuum interface of the testing unit provides a vacuum environment for components requiring negative pressure testing. The testing unit is used to perform airtightness testing and includes a pressure transmitter, a flow sensor, and connecting pipelines. A sealing unit seals all openings of the components to form a closed space. The pressure transmitter and flow sensor are connected in parallel in the pipeline of the testing chamber. The pressure transmitter is used to detect pressure changes in the chamber, and the flow sensor is used to detect leakage flow. The signal output terminal of the testing unit is connected to the electrical control system via the RS485 communication protocol. The electrical control system determines whether the airtightness of the components is qualified based on the pressure change or leakage flow within the set testing time.

[0012] More preferably, the electrical control system is equipped with a touch screen and a PLC controller. The digital input ports of the PLC controller are connected to various sensing elements, such as displacement encoders and pressure sensors, via cables to receive detection signals. The digital output ports are connected to various actuators, such as servo motor drivers, proportional valves, pressure relief valves, and pneumatic check valves, to output control signals. The analog input ports receive signals from the pressure sensors, and the analog output ports output signals to control the opening degree of the proportional valves. The touch screen and the PLC can communicate to display the sealing pressure, displacement position, and detection status of each channel in real time, and support parameter setting, historical data query, and fault diagnosis. In addition, the electrical control system can also be connected to the factory's MES system via Ethernet to realize the uploading of detection data and remote monitoring, meeting the needs of intelligent production.

[0013] More preferably, the T-shaped slide rail on the top surface of the base assembly is slidably connected to the connecting slider at the bottom of the sealing unit. The connecting slider is fixed to the guide rail by a quick locking mechanism, realizing the detachable installation of the sealing unit. In the displacement adjustment mechanism, the servo motor driver is connected to the PLC digital output port of the electronic control system through a cable, and the motor encoder is connected to the PLC digital input port through a cable. The PLC outputs a pulse signal to control the rotation of the servo motor, and the encoder feeds back the displacement signal to the PLC, forming a displacement closed-loop control. The pressure sensor is connected to the PLC analog input port through a cable. The PLC receives the pressure signal and outputs an analog signal to control the proportional valve, realizing pressure closed-loop control.

[0014] This invention provides a sealing device for airtightness testing of automotive parts, which has the following advantages:

[0015] This invention, through the combined design of a detachable sealing unit, a displacement adjustment mechanism, and a replaceable positioning pin, enables a single device to adapt to sealing openings of automotive parts with varying diameters and shapes. This reduces mold changeover time and mold costs. Simultaneously, the servo motor and ball screw combination of the displacement adjustment mechanism achieves sealing head positioning accuracy far exceeding that of traditional manual adjustment, ensuring the precision of the sealing position and reducing sealing failures caused by positioning deviations.

[0016] In addition, existing technologies are mostly single-channel or serial multi-channel detection. This invention designs multiple independent detection channels, each channel is equipped with an independent sealing unit and pressure regulation system, and the positioning, sealing and detection process of each channel is synchronously controlled by PLC. The detection time is the same as that of a single channel, but the number of detections is increased several times, which also improves the detection efficiency and can match the cycle time requirements of automobile production lines.

[0017] In addition, the entire process from component positioning, sealing, testing to result feedback is fully automated, reducing manual intervention and labor intensity, while also ensuring testing consistency and meeting the quality control needs of large-scale production. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0019] The accompanying drawings described below are only related to some embodiments of the invention and are not intended to limit the invention.

[0020] In the attached diagram:

[0021] Figure 1 A schematic diagram of the base assembly of the present invention is shown;

[0022] Figure 2 A schematic diagram of the ball screw of the present invention is shown;

[0023] Figure 3 A schematic diagram of the unfolded structure between the guide rail and the connecting slider of the present invention is shown;

[0024] Figure 4 A schematic diagram of the sealing unit of the present invention is shown;

[0025] Figure 5 A cross-sectional structural schematic diagram of the sealing unit of the present invention is shown;

[0026] Figure 6 The present invention is shown. Figure 5 Enlarged structural diagram at point A in the middle;

[0027] Figure 7 The present invention is shown. Figure 5 Enlarged structural diagram at point B;

[0028] Figure 8 A partial cross-sectional structural diagram of the nut of the present invention is shown.

[0029] List of reference numerals

[0030] 1. Base assembly; 11. Base plate; 12. Electrical control system; 2. Sealing unit; 201. Support frame; 202. Proportional valve; 203. Fixing frame; 3. Fixing ring; 4. Pressure regulating clamp; 41. Motor; 42. Rotary ring; 43. Moving rod; 4301. Clamping plate; 5. Connecting slider; 501. Locking block; 6. Guide rail; 7. Ball screw; 71. Screw; 72. Nut; 8. Support frame; 801. Servo motor. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. Based on the described 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.

[0032] Example: Please refer to the appendix. Figure 1 To be continued Figure 8 :

[0033] This invention proposes a sealing device for airtightness testing of automotive parts, comprising: a base assembly 1, a sealing unit 2, a fixing ring 3, a pressure regulating clamp 4, a connecting slider 5, a displacement adjusting mechanism, and a vacuum and air pressure supply system; the base assembly 1, serving as the load-bearing foundation of the device, is formed by welding steel plates. The base assembly 1 includes a base platform 11 and an electrical control system 12. T-shaped slide rails are provided on the base platform 11, with 3-6 sets of slide rails evenly distributed along the length of the base platform 11. Each set of slide rails has 2-4 slidable connecting sliders 5. The top of the slider 5 is equipped with a quick-locking mechanism, which is pneumatically locked. After locking, the positioning accuracy is ±0.1mm. It is used to fix the sealing unit 2. The top surface of the base 11 is equipped with an accessory positioning platform. The positioning platform is equipped with a detachable positioning pin. The positioning pin of the corresponding size can be replaced according to the positioning hole specifications of different accessories to ensure accurate positioning of accessories. The base 11 has reserved pipeline channels and cable trays inside for arranging pipelines and electrical control lines of vacuum and pneumatic systems to avoid pipeline wear or line aging caused by external interference.

[0034] In the embodiments disclosed herein, as shown in the appendix Figure 1 As shown, the pressure regulating clamp 4 includes a motor 41, a rotating ring 42, and a moving rod 43. The motor 41 is installed inside the support frame 201. A spur gear 4101 is coaxially connected to the drive shaft of the motor 41. The outer edge of the rotating ring 42 has teeth that mesh with the spur gear 4101. A helical gear ring is provided on the outer side of the inner end face of the rotating ring 42 and meshes with a helical gear outside the sleeve. The outer wall of the moving rod 43 has threads that mesh with the sleeve. The inner end is fixedly connected to a clamping plate 4301, which is snapped into a sliding groove inside the sealing unit 2. The motor 41 is electrically connected to the electrical control system 12. After the motor 41 is started by the control end, it drives the spur gear 4101 to rotate through the drive shaft. Through meshing, it drives the rotating ring 42 to rotate. The rotating ring 42 meshes with the helical gear ring and the helical gear to drive the sleeve to rotate. The thread on the inner wall of the sleeve drives the moving rod 43 to move, thereby driving the clamping plate 4301 to move, so as to achieve clamping and fixing of the parts.

[0035] In the embodiments disclosed herein, as shown in the appendix Figure 2 ,3 As shown in Figure 8, the displacement adjustment mechanism consists of a servo motor 801, a ball screw 7, and a guide rail 6 mounted on the top of the rear support frame 8. The servo motor is connected to the ball screw 7 via a coupling. The bottom of the nut 72 of the ball screw 7 is fixedly connected to the top surface of the rear sealing unit 2. One end of the screw 71 of the ball screw 7 is connected to the drive shaft of the servo motor 801, and the other end is rotatably connected to the right-angle plate connected to the top surface of the front support frame 8. A probe is provided on the outer end face of the support frame 8. The probe and the rangefinders on the front and rear sides of the top of the base 11 are on the same horizontal line. After the support frame 8 moves back and forth, the rangefinder can accurately measure the moving distance, so that the front and rear directions can be accurately positioned. The servo motor 801 drives the screw 71 to rotate, and through the nut 72, it drives the rear sealing unit 2 to move along the guide rail 6, so as to realize the axial positioning of the sealing unit 2 and the sealing port of the accessory. The displacement signal is fed back to the electronic control system 12 in real time through the encoder of the motor. The proportional valve 202 is electrically connected to the electronic control system 12, and the sealing pressure is controlled by adjusting the air pressure.

[0036] In the embodiments disclosed herein, as shown in the appendix Figure 6 As shown, the fixing ring 3 is an annular component. An annular groove is formed on the outer circumference of the fixing ring 3. Coaxial annular bars are respectively provided on both sides of the inner wall of the groove. The rotating ring 42 is engaged in the groove. The inner end face of the fixing ring 3 is fixedly connected to the fixing bracket 203. The end of the fixing bracket 203 is rotatably mounted with a sleeve with threads on the inner wall. A helical gear is fixedly provided on the outside of the sleeve. When the helical gear is rotated, it drives the sleeve to rotate synchronously, realizing synchronous transmission. The annular bars are used to form a radial limit for the rotating ring 42 embedded in the groove, without affecting the rotation of the rotating ring 42.

[0037] In this embodiment, the sealing unit 2 is internally equipped with a proportional valve 202, a pressure relief valve, a pressure sensor, a pneumatic check valve, and connecting pipes. The inlet of the proportional valve 202 is connected to the vacuum and air pressure supply system inside the electronic control system 12, and the outlet is connected to the inlet of each sealing unit 2 through branch pipes. Each branch pipe is equipped with a pneumatic check valve to maintain stable sealing pressure. The signal output of the pressure sensor is connected to the electronic control system 12 through a shielded cable to transmit the detected sealing pressure signal to the electronic control system 12 in real time. When the electronic control system 12 detects that the sealing pressure is lower than the set value, it outputs a signal to control the proportional valve 202 to increase the opening and supplement the air pressure. When the pressure is higher than the set value, it controls the pressure relief valve to open and relieve pressure, forming a pressure closed-loop control to ensure that the sealing pressure fluctuation range is controllable and stable. In addition, the pressure regulation system is also equipped with a pressure alarm threshold. When the pressure exceeds the threshold, the electronic control system 12 issues an alarm signal and stops the detection process.

[0038] In the embodiments disclosed herein, as shown in the appendix Figure 8As shown, a quick-locking mechanism is provided on the top of the connecting slider 5, and a locking block 501 is provided on the top of the quick-locking mechanism. The quick-locking mechanism is electrically connected to the control terminal inside the electronic control system 12. The locking block 501 is pneumatically locked to the guide rail 6. A T-shaped groove is provided on the bottom of the connecting slider 5, and a T-shaped slide rail is engaged inside the T-shaped groove. Distance sensors are installed on the opposite faces of the two connecting sliders 5 with corresponding positions. The distance sensors are electrically connected to the electronic control system 12. When the electric drive moving module inside the connecting slider 5 is started by the control terminal and moves on the T-shaped slide rail, the position of the connecting slider 5 is adjusted, and the left and right positions are fixed after positioning.

[0039] In the embodiments disclosed herein, as shown in the appendix Figure 3 As shown, the bottom of the sealing unit 2 is snapped onto the guide rail 6. The outer bottom plate of the guide rail 6 is fastened to the connecting slider 5 by bolts. The bottom of the guide rail 6 is provided with a positioning hole. The positioning hole cooperates with the positioning pin on the top of the connecting slider 5 to achieve initial positioning, and then is locked by a quick locking mechanism. The sealing unit 2 is equipped with a fixing ring 3, a pressure regulating clamp 4, a proportional valve 202 and a fixing frame 203. The bottom of the sealing unit 2 is provided with a support frame 201. The motor 41 is installed inside the support frame 201. The inner end face of the sealing unit 2 is provided with an air inlet. The top of the sealing unit 2 is connected to the electrical control system 12 through a pipeline. The inner end face of the sealing unit 2 has three layers of sealing ports. The sealing head contour is designed according to the shape of the sealing port of the accessory. An elastic sealing ring is embedded in the outer ring of the sealing port. The material is fluororubber, which is resistant to temperature from -20℃ to 200℃, and meets the compatibility requirements of the test medium. The compression of the sealing ring can be controlled at 10%-20% by subsequent pressure adjustment to ensure the sealing effect while avoiding excessive compression that leads to accelerated aging.

[0040] In this embodiment, the vacuum and air pressure supply system provides the sealing unit 2 with the compressed air or vacuum required for testing. It includes an air compressor, a vacuum generator, an air tank, a dryer filter, a shut-off valve, and piping. The air compressor's outlet is sequentially connected to the dryer filter and the air tank to remove moisture and impurities from the compressed air, preventing any impact on the sealing effect or damage to the valve. The air tank's outlet is divided into two paths: one path connects to the inlet of the proportional valve 202 of the pressure regulating system via a shut-off valve to provide sealing pressure to the sealing unit 2; the other path connects to the inlet of the vacuum generator via a shut-off valve. The vacuum end of the vacuum generator is connected via piping... The vacuum interface connected to the detection unit provides a vacuum environment for accessories requiring negative pressure testing. The detection unit is used to perform airtightness testing and includes a pressure transmitter, a flow sensor, and connecting pipelines. All openings of the accessories are sealed by the sealing unit 2 to form a closed space. The pressure transmitter and flow sensor are connected in parallel in the pipeline. The pressure transmitter is used to detect pressure changes inside the accessories, and the flow sensor is used to detect leakage flow. The signal output terminal of the detection unit is connected to the electrical control system 12 via the RS485 communication protocol. The electrical control system 12 determines whether the airtightness of the accessories is qualified based on the pressure change or leakage flow within the set detection time.

[0041] In this embodiment, the branch pipes, pressure relief valves, pressure sensors, and other components inside the sealing unit are not shown. All models used are existing products. The vacuum and air pressure supply system is an externally connected component that provides compressed air or vacuum to the sealing unit. All product models used are existing technologies. The exhaust pressure of the air compressor is 0.8 MPa, and the exhaust volume is 0.3 m³ / min. The vacuum generator is model ZH07BS with a vacuum degree of -90 kPa. The air tank has a volume of 50 L and a pressure of 0.8 MPa. The dryer filter has an accuracy of 0.01 μm. The PLC controller is a Siemens S7-1200 PLC, equipped with a 10.1-inch touch screen model KTP1000 as the human-machine interface. However, it is not limited to the above models and is only for illustration. Any alternative models that can be easily conceived should be included within the protection scope of this disclosure.

[0042] The working principle of this embodiment is as follows: The sealing device operates automatically throughout the entire process, and the specific steps are as follows:

[0043] 1) Parts matching preparation: Select the corresponding sealing unit 2 according to the specifications of the automotive parts to be tested, snap the sealing unit 2 onto the guide rail 6, fix the guide rail 6 to the connecting slider 5 with bolts, lock the quick locking mechanism, replace the positioning pin on the base 11 to match the positioning hole of the part, and set parameters such as sealing pressure and testing time through the touch screen.

[0044] 2) Part positioning: Place the part to be tested on the base 11. The positioning hole of the part cooperates with the positioning pin, triggering the electric drive moving module inside the connecting slider 5 to position it in the front-back direction. The PLC outputs a pulse signal to the servo motor 801 driver, which drives the servo motor 801 to rotate. Through the ball screw 7, the sealing unit 2 moves along the guide rail 6 until the sealing unit 2 is close to the sealing port of the part. The displacement encoder feeds back the displacement signal to the PLC in real time. When the sealing unit 2 reaches the preset position, the PLC controls the servo motor 801 to stop, positioning it in the left-right direction.

[0045] 3) Sealing Positioning and Pressure Regulation: After the motor 41 is started by the control end, it drives the spur gear 4101 to rotate through the drive shaft. The spur gear 4101 rotates through meshing. The spur gear 42 rotates through meshing with the helical gear ring and the helical gear. The helical gear ring rotates the sleeve. The thread on the inner wall of the sleeve drives the moving rod 43 to move, thereby moving the clamping plate 4301 to achieve clamping and fixing of the parts. Then, the PLC outputs an analog signal to the proportional valve 202 of the pressure regulation system. The proportional valve 202 opens to supply air to the inside of the sealing unit 2. The pressure sensor between the sealing unit 2 and the parts detects the sealing pressure in real time and transmits the signal to the PLC. When the pressure reaches the set value, the PLC controls the proportional valve 202 to maintain the opening, and at the same time the pneumatic check valve closes to lock the sealing pressure and complete the sealing.

[0046] 4) Air tightness test: If it is a positive pressure test, the PLC controls the vacuum and air pressure supply system to open the shut-off valve. Compressed air enters the inside of the component after being dried and filtered. When the pressure reaches the set test pressure, the PLC controls the shut-off valve to close and starts timing. The pressure transmitter of the detection unit monitors the pressure change inside the component in real time, and the flow sensor monitors the leakage flow. The data is transmitted to the PLC synchronously. If it is a negative pressure test, the PLC controls the vacuum generator to start, evacuates the inside of the component to the set vacuum level, closes the vacuum valve and starts timing. The pressure transmitter monitors the vacuum level change.

[0047] 5) Result Judgment and Feedback: After the detection time is reached, the PLC compares whether the pressure change and leakage flow are within the set thresholds. If both meet the thresholds, it is judged as qualified. The PLC controls the alarm light to light up green, and the touch screen displays "qualified" for the corresponding channel. At the same time, the detection data is stored and uploaded to the MES system. If any parameter exceeds the threshold, it is judged as unqualified. The PLC controls the alarm light to light up red, the buzzer sounds an alarm, and the touch screen displays the faulty channel and the specific parameters that exceed the standard, prompting the operator to troubleshoot.

[0048] 6) Inspection Completion and Reset: Regardless of whether the inspection is qualified or not, the PLC controls the pressure relief valve of the pressure regulation system to open, releasing the cylinder pressure of the sealing unit; controls the servo motor 801 to reverse, driving the sealing unit 2 away from the parts, the operator removes the parts that have been inspected, the device returns to the state of waiting to be inspected, and the next batch of parts can be inspected.

[0049] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A sealing device for airtightness testing of automotive parts, including: The base assembly (1), sealing unit (2), fixing ring (3), pressure regulating clamp (4), connecting slider (5), displacement adjusting mechanism and vacuum and air pressure supply system are characterized in that the base assembly (1) includes a base (11) and an electrical control system (12). The base (11) is provided with a T-shaped slide rail. The slide rail is evenly distributed in 3-6 groups along the length of the base (11). Each group of slide rails is provided with 2-4 connecting sliders (5). The top of the connecting slider (5) is provided with a quick locking mechanism. The top surface of the base (11) is provided with an accessory positioning platform. The positioning platform is equipped with a detachable positioning pin. The base (11) has reserved pipeline channels and cable grooves inside. The bottom of the sealing unit (2) is snapped onto the guide rail (6). The outer bottom plate of the guide rail (6) is fastened to the connecting slider (5) by bolts. The sealing unit (2) is equipped with a fixing ring (3), pressure regulating clamp (4), and a vacuum and air pressure supply system inside. Example valve (202) and fixing frame (203), the bottom of the sealing unit (2) is provided with a support frame (201), and the motor (41) is installed inside the support frame (201); an annular groove is opened on the outer circumferential surface of the fixing ring (3), the rotating ring (42) is snapped in the groove, and the fixing frame (203) is fixedly connected to the inner end face of the fixing ring (3); the pressure regulating clamp (4) includes a motor (41), a rotating ring (42) and a moving rod (43), the motor (41) is installed inside the support frame (201), the outer edge of the rotating ring (42) is provided with teeth, the teeth are meshed with the spur gear (4101), the outer side of the inner end face of the rotating ring (42) is provided with a helical gear ring, and the helical gear ring is meshed with the helical gear outside the sleeve; the top of the connecting slider (5) is provided with a quick locking mechanism, the top of the quick locking mechanism is provided with a locking block (501), and the locking block (501) is connected by a pneumatic locking guide rail (6). The displacement adjustment mechanism consists of a servo motor (801), a ball screw (7) and a guide rail (6) mounted on the top of the rear support frame (8). The servo motor is connected to the ball screw (7) via a coupling. One end of the screw (71) of the ball screw (7) is connected to the drive shaft of the servo motor (801), and the other end is rotatably connected to the right angle plate connected to the top surface of the front support frame (8).

2. The sealing device for airtightness testing of automotive parts according to claim 1, characterized in that, The inner end face of the sealing unit (2) is provided with an air inlet. The top of the sealing unit (2) is connected to the electrical control system (12) through a pipeline. The inner end face of the sealing unit (2) is provided with three layers of sealing ports. An elastic sealing ring is embedded in the outer ring of the sealing port. The material is fluororubber and the temperature resistance is -20℃ to 200℃.

3. The sealing device for airtightness testing of automotive parts according to claim 2, characterized in that, The fixing ring (3) is an annular component. The inner walls of the annular groove are respectively provided with coaxial annular bars. The end of the fixing frame (203) is rotatably installed with a sleeve with threads on the inner wall. A helical gear is fixedly provided on the outside of the sleeve.

4. The sealing device for airtightness testing of automotive parts according to claim 2, characterized in that, The drive shaft of the motor (41) is coaxially connected to a spur gear (4101). The outer wall of the moving rod (43) is threaded and meshes with the sleeve. The inner end of the moving rod (43) is fixedly connected to a clamping plate (4301). The clamping plate (4301) is engaged in the sliding groove inside the sealing unit (2). The motor (41) is electrically connected to the electrical control system (12).

5. The sealing device for airtightness testing of automotive parts according to claim 2, characterized in that, The quick locking mechanism is electrically connected to the control terminal inside the electronic control system (12). A T-shaped groove is provided at the bottom of the connecting slider (5), and a T-shaped slide rail is engaged inside the T-shaped groove. A distance sensor is installed on the opposite surface of the two connecting sliders (5) with corresponding positions. The distance sensor is electrically connected to the electronic control system (12).

6. The sealing device for airtightness testing of automotive parts according to claim 5, characterized in that, The bottom of the guide rail (6) is provided with a positioning hole, which cooperates with the positioning pin on the top of the connecting slider (5).

7. The sealing device for airtightness testing of automotive parts according to claim 1, characterized in that, The bottom of the nut (72) of the ball screw (7) is fixedly connected to the top surface of the rear sealing unit (2). The outer end face of the support frame (8) is provided with a probe, and the probe and the rangefinders on the front and rear sides of the top of the base (11) are on the same horizontal line.

8. The sealing device for airtightness testing of automotive parts according to claim 2, characterized in that, The sealing unit (2) is equipped with a proportional valve (202), a pressure relief valve, a pressure sensor, a pneumatic check valve and connecting pipes. The inlet of the proportional valve (202) is connected to the vacuum and air pressure supply system inside the electronic control system (12), and the outlet is connected to the inlet of each sealing unit (2) through branch pipes. Each branch pipe is equipped with a pneumatic check valve, and the signal output of the pressure sensor is connected to the electronic control system (12) through a shielded cable.

9. The sealing device for airtightness testing of automotive parts according to claim 7, characterized in that, The vacuum and air pressure supply system provides the compressed air or vacuum required for the sealing unit (2) for testing. It includes an air compressor, a vacuum generator, an air tank, a dryer filter, a shut-off valve, and pipelines. The outlet of the air compressor is connected to the dryer filter and the air tank in sequence. The outlet of the air tank is divided into two paths. One path is connected to the inlet of the proportional valve (202) of the pressure regulating system through a shut-off valve. The other path is connected to the inlet of the vacuum generator through a shut-off valve. The vacuum end of the vacuum generator is connected to the vacuum interface of the detection unit through a pipeline. The detection unit is used for air tightness testing and includes a pressure transmitter, a flow sensor, and connecting pipelines.

10. The sealing device for airtightness testing of automotive parts according to claim 8, characterized in that, The T-shaped slide rail on the top surface of the base assembly (1) is slidably connected to the connecting slider (5) at the bottom of the sealing unit (2). In the displacement adjustment mechanism, the servo motor (801) driver is connected to the PLC digital output port of the electronic control system (12) through a cable, and the motor encoder is connected to the digital input port of the PLC through a cable. The PLC outputs a pulse signal to control the rotation of the servo motor (801), and the encoder feeds back the displacement signal to the PLC to form a displacement closed-loop control. The pressure sensor is connected to the analog input port of the PLC through a cable. The PLC receives the pressure signal and outputs an analog signal to control the proportional valve (202).

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