Track traffic passenger room air conditioner airtightness test device and method

Abstract

The invention provides a rail transit passenger room air conditioner airtightness test device and method.The rail transit passenger room air conditioner airtightness test device comprises a plugging tool, an air path assembly and a control system, the plugging tool comprises a covering part, a pressure applying part and a ventilation part, the pressure applying part is connected with the covering part, and the ventilation part is connected with the air path assembly; the driving part can drive the covering part to be in press-fit sealing with an air inlet of the passenger room air conditioner and has the covering area at least larger than the area of the air inlet of the passenger room air conditioner, a closed cavity is formed, the covering part is provided with a pressure sensor for detecting the air pressure of the closed cavity, and the ventilation part is arranged on the covering part and used for being communicated with the closed cavity and allowing air to be inflated. According to the plugging tool, plugging sealing capable of covering air inlets of different types of air conditioners is provided through the pressure applying part and the covering part of the plugging tool, operation is rapid, and through cooperation with on-off control of the control system, when the air path assembly is pressed and sealed at the covering part, rapid inflation and pressure applying are achieved, and safe pressure relief is conducted when a pressed air path is abnormal.

Description

Technical Field

[0001] The present invention relates to the technical field of airtightness testing, and in particular to an airtightness testing device and method for rail transit passenger compartment air conditioning. Background Art

[0002] Existing airtightness test benches use sealing fixtures to seal air conditioning ducts or passenger compartment doors and windows to ensure the test space is airtight. The test space is then inflated to the target pressure using a fan or air tank. Inflation is then stopped, and the pressure changes over time are monitored. The pressure decay curve is recorded, and the leakage rate is calculated based on the pressure drop rate to determine whether the target is met. For example, Chinese Patent No. 201811468306.4 discloses equipment and methods for testing airtightness in rail transit air conditioning systems. These include a pressure supply unit, a detection unit, and a control unit. The pressure supply unit includes a variable-frequency fan, a pressure supply pipe connected to the variable-frequency fan, and an airtight joint connected to the end of the pressure supply pipe.

[0003] However, the air tightness test is connected with the sealing of the air conditioning vents. Due to the different models of air conditioners in different EMUs, it is not possible to modularly adapt to multiple models for sealing during air tightness testing. The sealing speed is slow and the sealing quality is low. The sealing speed and sealing quality directly affect the efficiency and accuracy of the testing operation. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and propose a rail transit passenger compartment air conditioning air tightness test device to solve the technical problem in the existing technology that it cannot modularly adapt to multiple vehicle models for sealing during air tightness detection.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a rail transit passenger compartment air conditioning airtightness test device, comprising: The sealing tool comprises a covering portion, a pressure-applying portion, and a vent portion. The pressure-applying portion is connected to the covering portion and can drive the covering portion to press and seal with the air inlet of the passenger compartment air conditioner. The covering portion has a covering area that is at least larger than the area of ​​the air inlet of the passenger compartment air conditioner to form a closed chamber. The covering portion is provided with a pressure sensor for detecting the air pressure in the closed chamber. The vent portion is provided on the covering portion for communicating with the closed chamber and allowing gas to enter. an air passage assembly connected to the vent portion and used for filling with gas; and A control system is electrically connected to the gas circuit assembly and the pressure sensor, and is used to control the on / off and / or pressure relief of the gas circuit assembly according to the signal fed back by the pressure sensor.

[0006] In some embodiments, the covering part includes a pressure plate, and the pressure-applying part includes a gantry and a telescopic cylinder. The telescopic cylinder is fixedly mounted on the gantry and forms a detection area for the air conditioner to be inserted between the gantry and the ground. The pressure plate is mounted on the telescopic end of the telescopic cylinder, and the telescopic cylinder drives the pressure plate to rise and fall vertically in the detection area.

[0007] In some embodiments, the covering portion includes a sealing box, the top of the sealing box has an opening for covering the air inlet of the air conditioner, and the pressure-applying portion includes a telescopic cylinder and a pressure rod, one end of the telescopic cylinder is hinged to the sealing box, and the other telescopic end is hinged to the pressure rod, the pressure rod is hinged to the top edge of the sealing box through a bracket, and the telescopic cylinder drives the pressure rod to flip downward toward the opening.

[0008] In some embodiments, the air circuit assembly includes an air intake device, a filter assembly, a first air circuit and a second air circuit. The air inlet of the filter assembly is connected to the air supply port of the air intake device, and the air outlet of the filter assembly is connected in parallel with the first air circuit and the second air circuit. The first air circuit is used to connect to the ventilation part for supplying pressurized gas, and the second air circuit is used to connect to the telescopic cylinder for providing compressed gas for the extension and contraction of the cylinder.

[0009] In some embodiments, the filter assembly includes an air filter, an oil mist separator, a pressure reducing valve, and a pressure relief valve connected end to end in sequence, and a total wind pressure sensor is also provided between the pressure relief valve and the first air path and the second air path.

[0010] In some embodiments, the first air circuit includes an inflation solenoid valve, a throttle valve, a connecting pipe and an exhaust solenoid valve, the throttle valve is connected to the inflation solenoid valve, the connecting pipe and the exhaust solenoid valve are connected in parallel with the throttle valve, the inflation solenoid valve is connected to the filter assembly, and the connecting pipe is connected to the sealing tool.

[0011] In some embodiments, the second air circuit includes a one-way valve and a five-way solenoid valve. The five-way solenoid valve is connected to the one-way valve and the corresponding air circuit of the telescopic cylinder. The other end of the one-way valve is connected to the filter assembly to allow compressed gas to flow in one direction along the filter assembly to the five-way solenoid valve.

[0012] In some embodiments, the air intake device includes an air storage cylinder, which is connected to the filter assembly, and an electromagnetic drain valve is provided at the bottom of the air storage cylinder.

[0013] In some embodiments, the control system includes an industrial computer and a data acquisition module, the industrial computer is electrically connected to the data acquisition module, the data acquisition module is electrically connected to the pressure sensor, the industrial computer is electrically connected to the pressure-applying part and the air circuit assembly, controls the extension and contraction movement of the pressure-applying part, and controls the on / off and / or pressure relief of the air circuit assembly, and an experimental table is installed on the outside of the industrial computer.

[0014] In a second aspect, the present invention further provides a test method for a rail transit passenger compartment air conditioning airtightness test device as described in any one of the above, comprising the following steps: Set pressure safety thresholds and pressure drop rate abnormality thresholds in the control system; Connect the product to be tested to the air outlet of the air tightness test bench, adjust the pressure and flow, and fill the product with gas at a certain pressure; When the target pressure is reached, inflation is stopped and the monitoring system monitors the pressure changes and determines whether the leakage exceeds the standard based on the pressure drop rate; When the test pressure exceeds the set safety threshold, the emergency pressure relief valve is activated and the gas source is cut off; When the pressure drop rate is greater than the pressure drop rate abnormal threshold, the emergency pressure relief valve is activated and the gas source is cut off.

[0015] Compared with the existing technology, the rail transit passenger compartment air-conditioning air-tightness test device provided by the present invention provides a sealing seal that can be covered on the air inlets of different models of air conditioners through the pressure-applying part and the covering part of the sealing tool. It is fast to operate and cooperates with the on-off control of the control system to enable the air path component to be quickly inflated and pressurized when the covering part is pressed and sealed, and to safely relieve pressure when the pressurized air path is abnormal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 2 is a schematic structural diagram of a rail transit passenger compartment air conditioning airtightness test device provided by an embodiment of the present invention; Figure 2 This is a structural diagram of a blocking tool for a rail transit passenger compartment air-conditioning airtightness test device provided by an embodiment of the present invention; Figure 3 This is another structural diagram of a blocking tool for a rail transit passenger compartment air-conditioning airtightness test device provided by an embodiment of the present invention; Figure 4 This is a structural diagram of an air circuit component of a rail transit passenger compartment air-conditioning airtightness test device provided by an embodiment of the present invention; Figure 5 It is a control system block diagram of a rail transit passenger compartment air conditioning airtightness test device provided by an embodiment of the present invention.

[0017] Description of reference numerals: 1. Sealing tool; 11. Covering unit; 111. Pressing plate; 112. Sealing box; 12. Pressing unit; 121. Gantry; 122. Telescopic cylinder; 123. Pressing rod; 13. Ventilation unit; 101. Pressure sensor; 2. Air circuit assembly; 21. Air intake device; 22. Filter assembly; 221. Air filter; 222. Oil mist separator; 223. Pressure reducing valve; 224. Pressure relief valve; 225. Total air pressure sensor; 23. First air circuit; 231. Charging solenoid valve; 232. Throttle valve; 233. Connecting pipe; 234. Exhaust solenoid valve; 24. Second air circuit; 241. Check valve; 242. Five-way solenoid valve; 3. Control system; 31. Industrial computer; 32. Data acquisition module; 33. Experimental platform. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] In order to solve the technical problems of not being able to modularly adapt to multiple vehicle models for sealing during air-tightness testing, slow sealing speed and low sealing quality, the present invention provides a rail transit passenger compartment air-tightness test device, which can provide a sealing seal that can be covered on air inlets of different models of air conditioners through the pressure-applying part 12 and the covering part 11 of the sealing tool 1, has fast operation, and under the on-off control of the control system 3, the air path component 2 is quickly inflated and pressurized when the covering part 11 is pressed and sealed, and safely relieves pressure when the pressurized air path is abnormal.

[0020] It should be noted that the rail transit passenger compartment air-conditioning air-tightness test device described in the present invention is used for but not limited to rail transit passenger compartment air-conditioning, etc. For the convenience of explanation, in the present invention, only the rail transit passenger compartment air-conditioning air-tightness test device applied to rail transit passenger compartment air-conditioning is used as an example for explanation, and the principle of applying the rail transit passenger compartment air-conditioning air-tightness test device to other types of equipment is essentially the same as the principle applied to rail transit passenger compartment air-conditioning, and will not be described one by one here.

[0021] See also Figure 1 , Figure 1Schematic diagram of the structure of the rail transit passenger compartment air-tightness test device in one embodiment of the present invention, the rail transit passenger compartment air-tightness test device includes a sealing tool 1, an air path component 2 and a control system 3, the sealing tool 1 includes a covering part 11, a pressure-applying part 12 and a venting part 13, the pressure-applying part 12 is connected to the covering part 11, and can drive the covering part 11 to press and seal with the air inlet of the passenger compartment air conditioner, with a covering area at least larger than the area of ​​the air inlet of the passenger compartment air conditioner, forming a closed chamber, the covering part 11 is provided with a pressure sensor 101 for detecting the air pressure in the closed chamber, the venting part 13 is provided with a pressure sensor 101 for detecting the air pressure in the closed chamber, and the pressure-applying part 12 is provided with a pressure sensor 101 for detecting the air pressure in the closed chamber. The air section 13 is mounted on the cover 11 and connects the sealed chamber to the air inlet. The air inlet of the rail transit passenger compartment air conditioner is opposite the cover 11. The pressure-applying section 12 is activated to drive the cover 11 downward toward the rail transit passenger compartment air conditioner's air inlet, forming a seal. The cover can be adjusted to accommodate different air inlet sizes. The air circuit assembly 2 is connected to the air vent 13 and is used to inject air. The control system 3 is electrically connected to the air circuit assembly 2 and the pressure sensor 101 and is used to control the on / off and / or pressure relief of the air circuit assembly 2 based on the signal fed back by the pressure sensor 101. The modular sealing fixture is compatible with multiple vehicle models and can be quickly replaced to accommodate different EMU air conditioning interfaces.

[0022] In this embodiment, a modular sealing tool 1 is used to seal the air-conditioning duct to form a closed test environment. The air path component 2 fills the test space with compressed air or nitrogen to reach the target pressure. After the inflation is stopped, the pressure sensor 101 monitors the pressure changes in real time, records the pressure decay curve, and determines whether the leakage exceeds the standard based on the pressure drop rate.

[0023] In one embodiment, see Figure 1 and Figure 2 In order to achieve a press-fit seal from top to bottom, the covering portion 11 includes a pressing plate 111, and the pressure-applying portion 12 includes a gantry 121 and a telescopic cylinder 122. The telescopic cylinder 122 is fixedly mounted on the gantry 121, and a detection area for the air conditioner to be inserted is formed between the pressing plate 111 and the ground. The pressing plate 111 is mounted on the telescopic end of the telescopic cylinder 122, and the telescopic cylinder 122 drives the pressing plate 111 to rise and fall vertically in the detection area. A sealing gasket covering the entire lower surface of the pressing plate 111 is provided at the bottom of the pressing plate 111. The pressing plate 111 is pressed down to the air inlet of the air conditioner, and the sealing gasket is pressed against the air inlet to form a seal. When the size of the air inlet of the air conditioner is smaller than the size range of the pressing plate 111, press-fit sealing can be performed to achieve a high adaptability.

[0024] In one embodiment, see Figure 1 and Figure 3When the air conditioner is pressed onto the sealing box 112, and the telescopic action of the telescopic cylinder 122 and the pressure rod 123 is coordinated, the pressure rod 123 is pushed down to press the outer convex edge of the air conditioner to form a seal.

[0025] In this embodiment, the number of the sealing boxes 112 can be set according to the needs of the air conditioner to be fully enclosed and sealed in the above manner.

[0026] In one embodiment, see Figure 1 The sealing tool 1 includes a sealing box 112 mode and a gantry 121 mode, and the two sealing tools 1 are connected to the air circuit component 2 through a three-way valve. The air circuit component 2 is switched and connected to the ventilation part 13 of any one of the sealing tools 1 to form an air supply for subsequent air tightness detection.

[0027] It can be understood that there can be multiple plugging tools in the sealing box 112 mode, which can be switched at any time, and corresponding multi-way valves can be used for connection and channel switching.

[0028] In one embodiment, see Figure 1 and Figure 4 In order to provide an air source and simultaneously provide compressed gas to the cylinder, the air circuit assembly 2 includes an air intake device 21, a filter assembly 22, a first air circuit 23, and a second air circuit 24. The air inlet of the filter assembly 22 is connected to the air supply port of the air intake device 21, and the air outlet of the filter assembly 22 is connected in parallel with the first air circuit 23 and the second air circuit 24. The first air circuit 23 is used to connect to the ventilation part 13 for supplying pressurized gas, and the second air circuit 24 is used to connect to the telescopic cylinder 122 for providing compressed gas for cylinder expansion and contraction. The air circuit assembly 2 is the core air supply and control system for the airtightness test, and is composed of the air intake device 21, the filter assembly 22, the first air circuit 23, and the second air circuit 24. The structure is as follows: Figure 4 Its core functions include providing test gas to the plugging tool 1 and filling it into the air-conditioning chamber to be tested; providing a power source for the telescopic cylinder 122 of the pressure-applying part 12; and realizing automatic control of inflation, pressure stabilization, and pressure relief.

[0029] Furthermore, the filter assembly 22 includes an air filter 221, an oil mist separator 222, a pressure reducing valve 223, and a pressure relief valve 224, connected end-to-end. A total air pressure sensor 101 is also installed between the pressure relief valve 224 and the first and second air paths 23 and 24. The air intake device 21 includes an air reservoir connected to the filter assembly 22. A solenoid drain valve is installed at the bottom of the air reservoir. The air intake device 21 utilizes an air reservoir, a compressed air storage container, to provide a stable air source and buffer supply pressure fluctuations. A solenoid drain valve is installed at the bottom to periodically and automatically drain condensed water, preventing moisture from entering the air path and affecting test accuracy or damaging the equipment. The air flow path is divided between the air intake device 21 and the filter assembly 22, and then into the first and second air paths 23 and 24. The air filter 221 removes dust and particulate matter from the air. The oil mist separator 222 separates oil and liquid water from the compressed air. The pressure reducing valve 223 reduces the air pressure to the set operating pressure. Pressure relief valve 224 has a dual function: normally venting air to the downstream air path; and urgently releasing air to the atmosphere in the event of overpressure. Total air pressure sensor 225: Located at the outlet of pressure relief valve 224, it monitors the total air path pressure in real time, feeding this data back to control system 3 and triggering pressure relief in the event of overpressure.

[0030] Furthermore, in order to form a test gas charging and discharging circuit, the first gas path 23 includes an inflation solenoid valve 231, a throttle valve 232, a connecting pipe 233 and an exhaust solenoid valve 234, which supply / exhaust gas to the vent 13 of the plugging tool 1 and control the test chamber pressure. The throttle valve 232 is connected to the inflation solenoid valve 231, and the connecting pipe 233 and the exhaust solenoid valve 234 are connected in parallel with the throttle valve 232. The inflation solenoid valve 231 is connected to the filter assembly 22, and the connecting pipe 233 is connected to the plugging tool 1. The inflation solenoid valve 231 opens / closes the inflation channel under the instruction of the control system 3. The throttle valve 232 is used to adjust the inflation flow rate, avoid pressure shock, and ensure smooth pressure increase. The exhaust solenoid valve 234 discharges the test chamber gas at the end of the test; in an emergency, it is linked with the pressure relief valve 224 to quickly relieve pressure, such as overpressure or leakage rate exceeding the standard.

[0031] Furthermore, in order to form a cylinder power circuit, the second air circuit 24 includes a one-way valve 241 and a five-way solenoid valve 242, which provide compressed gas to the telescopic cylinder 122 of the pressure-applying part 12 to drive the covering part 11 to press / release. The five-way solenoid valve 242 is connected to the one-way valve 241 and the corresponding air circuit of the telescopic cylinder 122. The other end of the one-way valve 241 is connected to the filter assembly 22, so that the compressed gas can flow along the filter assembly 22 to the five-way solenoid valve 242 in one direction. The one-way valve 241 ensures that the gas only flows from the filter assembly 22 to the five-way solenoid valve 242 to prevent the cylinder air pressure from flowing back. The five-way solenoid valve 242 controls the extension and contraction direction of the cylinder, the lifting and lowering of the pressure plate 111 / the flipping of the pressure rod 123; it receives a signal from the control system 3 and switches the air circuit to realize the tightening or loosening action.

[0032] The working process of the air circuit is as follows: in the preparation stage, the air storage cylinder accumulates pressure, the gas is filtered and purified, and the pressure is monitored by the total air pressure sensor 225 to be normal; for sealing and inflation, the five-way solenoid valve 242 is actuated to control the telescopic cylinder 122 to drive the cover part 11 to be compressed and sealed, and the inflation solenoid valve 231 is opened to allow the gas to be adjusted by the throttle valve 232 and then filled into the test chamber; for test monitoring, the chamber pressure is monitored in real time by the pressure sensor 101, and the data is fed back to the control system 3. After reaching the target pressure, the inflation solenoid valve 231 is closed, and the system records the pressure decay curve; for end / emergency processing, when the pressure ends normally, the exhaust solenoid valve 234 is opened to release the pressure, and the cylinder 122 is reset. In case of abnormality, the pressure relief valve 224 and the exhaust solenoid valve 234 are started at the same time for dual-path emergency pressure relief, and the gas source is cut off, that is, the inflation solenoid valve 231 is closed.

[0033] As you can understand, the air circuit features two independent control loops. The first air circuit 23 focuses on test accuracy, with a throttle valve for steady flow and dual solenoid valves for rapid response. The second air circuit 24 is isolated by a check valve 241 to prevent cylinder movement from interfering with test pressure. Multiple safety features are also included: a total air pressure sensor 225 and a pressure relief valve 224 provide overpressure protection at the source; and an exhaust solenoid valve 234 provides rapid pressure relief at the terminal. Furthermore, the electromagnetic drain valve, combined with multi-stage filtration, ensures convenient maintenance, extending equipment life and reducing maintenance frequency.

[0034] In one embodiment, see Figure 1 and Figure 5The control system 3 includes an industrial computer 31 and a data acquisition module 32. The industrial computer 31 is electrically connected to the data acquisition module 32, which is in turn electrically connected to the pressure sensor 101. The industrial computer 31 is electrically connected to both the pressure-applying unit 12 and the gas circuit assembly 2, controlling the expansion and contraction of the pressure-applying unit 12 and the on / off switching and / or pressure relief of the gas circuit assembly 2. A test bench 33 is externally mounted on the industrial computer 31. The control system 3 utilizes a hierarchical architecture comprised of the industrial computer 31, the data acquisition module 32, and electrical control components to achieve fully automated testing, precise pressure control, and multi-level safety protection.

[0035] The industrial computer 31 runs independently developed control software to automate the test process, including inflation, pressure maintenance, pressure relief, and data logging. A display is installed on the test bench 33, displaying a real-time pressure-time curve and enabling the configuration of mechanical parameters such as vehicle type, target pressure, and test time. The test bench 33 also includes an external USB 3.0 port to support Bluetooth keyboards and mice, external printers, and data export.

[0036] Furthermore, the data acquisition module 32 primarily includes a data acquisition board that converts analog signals into digital signals for processing by an industrial computer. It also outputs analog quantities for controlling actuators such as electrical proportional valves. It also includes a pressure transmitter that collects pressure signals from the gas circuit and converts them into electrical signals for output to the data acquisition board.

[0037] The present invention further provides a test method for the rail transit passenger compartment air conditioning airtightness test device as described in any one of the above, comprising the following steps: Setting a pressure safety threshold and a pressure drop rate abnormality threshold in the control system 3; Connect the product to be tested to the air outlet of the air tightness test bench, adjust the pressure and flow, and fill the product with gas at a certain pressure; When the target pressure is reached, inflation is stopped and the monitoring system monitors the pressure changes and determines whether the leakage exceeds the standard based on the pressure drop rate; When the test pressure exceeds the set safety threshold, the emergency pressure relief valve is activated and the gas source is cut off; When the pressure drop rate is greater than the pressure drop rate abnormal threshold, the emergency pressure relief valve is activated and the gas source is cut off.

[0038] If the test pressure exceeds the set safety threshold, such as >1000Pa, it may cause damage to the equipment or the tested part; if the pressure drop rate during the pressure holding stage is abnormal, such as >10Pa / s, it indicates a serious leak or pipeline rupture; if the pressure sensor has no signal or the data is abnormal, such as continuous zero value / full scale; in such cases, the system achieves rapid response through a multi-level feedback mechanism. The pressure, temperature, and flow sensors collect data in real time and transmit it to the industrial computer. The industrial computer compares the data with the preset safety range and determines it as abnormal if it exceeds the range; the emergency pressure relief valve is activated, the gas source is cut off, and a software alarm is sent simultaneously.

[0039] The emergency pressure relief valve can automatically open when the pressure is abnormal, quickly releasing excess pressure, and the alarm system can promptly remind the operator when an abnormal situation is detected so that appropriate safety measures can be taken.

[0040] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A rail transit passenger compartment air conditioning airtightness test device, characterized in that: include: The sealing tool comprises a covering portion, a pressure-applying portion, and a vent portion. The pressure-applying portion is connected to the covering portion and can drive the covering portion to press and seal with the air inlet of the passenger compartment air conditioner. The covering portion has a covering area that is at least larger than the area of ​​the air inlet of the passenger compartment air conditioner to form a closed chamber. The covering portion is provided with a pressure sensor for detecting the air pressure in the closed chamber. The vent portion is provided on the covering portion for communicating with the closed chamber and allowing gas to enter. an air passage assembly connected to the vent portion and used for filling with gas; and A control system is electrically connected to the gas circuit assembly and the pressure sensor, and is used to control the on / off and / or pressure relief of the gas circuit assembly according to the signal fed back by the pressure sensor.

2. The rail transit passenger compartment air conditioning airtightness test device according to claim 1 is characterized in that: The covering part includes a pressure plate, and the pressure-applying part includes a gantry and a telescopic cylinder. The telescopic cylinder is fixedly mounted on the gantry and forms a detection area for the air conditioner to be inserted between the gantry and the ground. The pressure plate is mounted on the telescopic end of the telescopic cylinder, and the telescopic cylinder drives the pressure plate to rise and fall vertically in the detection area.

3. The rail transit passenger compartment air conditioning airtightness test device according to claim 1, characterized in that: The covering part includes a sealing box, the top of the sealing box has an opening for covering the air inlet of the air conditioner, and the pressure-applying part includes a telescopic cylinder and a pressure rod, one end of the telescopic cylinder is hinged to the sealing box, and the other telescopic end is hinged to the pressure rod, and the pressure rod is hinged to the top edge of the sealing box through a bracket, and the telescopic cylinder drives the pressure rod to flip downward toward the opening.

4. The rail transit passenger compartment air conditioning airtightness test device according to claim 1 or 2, characterized in that: The air path assembly includes an air intake device, a filter assembly, a first air path and a second air path. The air inlet of the filter assembly is connected to the air supply port of the air intake device, and the air outlet of the filter assembly is connected in parallel with the first air path and the second air path. The first air path is used to connect to the ventilation part for supplying pressurized gas, and the second air path is used to connect to the telescopic cylinder for providing compressed gas for the extension and contraction of the cylinder.

5. The rail transit passenger compartment air conditioning airtightness test device according to claim 4, characterized in that: The filter assembly includes an air filter, an oil mist separator, a pressure reducing valve and a pressure relief valve which are connected end to end in sequence. A total wind pressure sensor is also provided between the pressure relief valve and the first air path and the second air path.

6. The rail transit passenger compartment air conditioning airtightness test device according to claim 4, characterized in that: The first air circuit includes an inflation solenoid valve, a throttle valve, a connecting pipe and an exhaust solenoid valve. The throttle valve is connected to the inflation solenoid valve, the connecting pipe and the exhaust solenoid valve are connected in parallel with the throttle valve, the inflation solenoid valve is connected to the filter assembly, and the connecting pipe is connected to the sealing tool.

7. The rail transit passenger compartment air conditioning airtightness test device according to claim 4, characterized in that: The second air circuit includes a one-way valve and a five-way solenoid valve. The five-way solenoid valve is connected to the one-way valve and the corresponding air circuit of the telescopic cylinder. The other end of the one-way valve is connected to the filter assembly to allow compressed gas to flow in one direction along the filter assembly to the five-way solenoid valve.

8. The rail transit passenger compartment air conditioning airtightness test device according to claim 4, characterized in that: The air intake device includes an air storage cylinder, which is connected to the filter assembly. An electromagnetic drain valve is provided at the bottom of the air storage cylinder.

9. The rail transit passenger compartment air conditioning airtightness test device according to claim 1, characterized in that: The control system includes an industrial computer and a data acquisition module. The industrial computer is electrically connected to the data acquisition module, which is electrically connected to the pressure sensor. The industrial computer is electrically connected to the pressure-applying part and the gas circuit assembly to control the extension and contraction of the pressure-applying part, as well as the on / off switching and / or pressure relief of the gas circuit assembly. A laboratory bench is installed on the outside of the industrial computer.

10. A test method, characterized in that: The rail transit passenger compartment air conditioning airtightness test device according to any one of claims 1 to 9 comprises the following steps: Set pressure safety thresholds and pressure drop rate abnormality thresholds in the control system; Connect the product to be tested to the air outlet of the air tightness test bench, adjust the pressure and flow, and fill the product with gas at a certain pressure; When the target pressure is reached, inflation is stopped and the monitoring system monitors the pressure changes and determines whether the leakage exceeds the standard based on the pressure drop rate; When the test pressure exceeds the set safety threshold, the emergency pressure relief valve is activated and the gas source is cut off; When the pressure drop rate is greater than the pressure drop rate abnormal threshold, the emergency pressure relief valve is activated and the gas source is cut off.

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