Railway vehicle air conditioning system integration test device and test method

Abstract

The present application relates to the field of vehicle test technology, and provides a rail vehicle air conditioning system integrated test device and test method, the device comprises: a mobile test bench, including a control system, a vacuum pump, an electronic scale and a shared pipeline network, the shared pipeline network includes a shared main pipe, the first end is connected to the external nitrogen source, the suction port of the vacuum pump, the filling bottle and the exhaust port through the control valve group respectively; a wireless acquisition box is configured as a physically separate structure independent of the mobile test bench, including a medium passage, a pressure sensor and a wireless transmission module; the second end of the shared main pipe is connected to the input end of the medium passage through a detachable pipeline, and a locking valve is arranged on the medium passage; the control system includes a controller and a wireless receiving module, and the controller performs bidirectional wireless sensing data communication with the wireless transmission module through the wireless receiving module. The present application realizes the automation, integration, precision and digitization of the rail vehicle air conditioning system test process.

Description

Technical Field

[0001] This invention relates to the field of vehicle testing technology, and in particular to an integrated testing device and method for air conditioning systems of rail vehicles. Background Technology

[0002] With the rapid development of the rail transit industry, the reliability of air conditioning systems directly affects passenger comfort and train operation stability. The piping sealing performance, vacuum level, and refrigerant charging accuracy of air conditioning systems are their core performance indicators. Currently, functional testing of air conditioning systems after maintenance often relies on decentralized equipment and step-by-step operations, such as using a vacuum pump for vacuuming, manually charging refrigerant, and using independent pressure gauges to test pressure holding performance. This results in cumbersome operations, low testing efficiency, and fragmented data that is difficult to manage uniformly.

[0003] Furthermore, existing testing equipment is mostly manually operated, which is prone to inaccurate results due to human error. It also lacks the ability to automatically extract, upload, and trace test data, hindering the standardization and information management of maintenance processes. Additionally, some testing equipment has limited functionality and cannot adapt to the testing needs of different vehicle models' air conditioning systems, resulting in poor versatility. Summary of the Invention

[0004] This invention provides an integrated testing device and method for rail vehicle air conditioning systems, which integrates pressure holding test, vacuum test, and refrigerant charging test functions, realizing the automation, integration, precision and digitalization of the rail vehicle air conditioning system testing process.

[0005] In a first aspect, the present invention provides an integrated test device for a rail vehicle air conditioning system, comprising: The mobile test bench includes a control system, a vacuum pump, an electronic scale for carrying an external refrigerant charging bottle, and a shared pipeline network. The shared pipeline network includes a shared main pipe, the first end of which is connected to an external nitrogen source, the suction port of the vacuum pump, the refrigerant charging bottle, and the exhaust port through different control valve groups. The wireless acquisition box is a physically separate structure independent of the mobile test bench, including a medium passage, a pressure sensor, and a wireless transmission module; wherein, the second end of the common main pipe is connected to the input end of the medium passage through a detachable pipe, the output end of the medium passage is provided with a docking terminal for connecting to the air conditioning system pipe interface, and the medium passage is provided with a locking valve for locking the pipe pressure. The control system includes a controller and a wireless receiving module. The controller communicates bidirectionally with the wireless transmission module via the wireless receiving module to transmit sensor data.

[0006] In some embodiments, during a pressure holding test, the locking valve is closed to lock high-pressure nitrogen gas within the air conditioning system, and the detachable pipeline is disconnected from the wireless acquisition box to allow the wireless acquisition box to move with the vehicle.

[0007] In some embodiments, the wireless acquisition box further includes a temperature sensor, and the controller is used to dynamically compensate and correct the original pressure value collected by the pressure sensor based on the real-time temperature change fed back by the temperature sensor, and obtain the air tightness of the air conditioning system based on the corrected pressure value.

[0008] In some embodiments, the temperature sensor includes a temperature probe extending outward from the housing of the wireless acquisition box.

[0009] In some embodiments, the wireless acquisition box is fixed to the outer wall of the air conditioning system's pipes via a fixing structure on its housing surface, so that the temperature probe is attached to the surface of the low-pressure pipes of the air conditioning system to obtain the real-time temperature of the fluid in the pipes being measured.

[0010] In some embodiments, the common pipeline network further includes a charging branch connected to the refrigerant charging bottle, a vacuum branch connected to the vacuum pump intake port, a nitrogen supply branch connected to an external high-pressure nitrogen source, and an exhaust branch connected to an atmospheric exhaust port. The first end of the common main pipe is connected in parallel to the charging branch, the vacuum branch, the nitrogen supply branch, and the exhaust branch.

[0011] In some embodiments, the control valve group includes a first valve connected in series with the charging branch, a second valve connected in series with the nitrogen supply branch, a third valve connected in series with the vacuum branch, and a fourth valve connected in series with the exhaust branch.

[0012] In some embodiments, the medium passage includes a high-pressure medium branch and a low-pressure medium branch that are independent of each other. The input ends of the high-pressure medium branch and the low-pressure medium branch are connected in parallel to serve as the input end of the medium passage. The output ends of the high-pressure medium branch and the low-pressure medium branch are respectively connected to a first docking terminal and a second docking terminal that serve as docking terminals. The first docking terminal and the second docking terminal are used to connect to the high-pressure port and the low-pressure port of the air conditioning system, respectively.

[0013] In some embodiments, the pressure sensor includes a first pressure sensor disposed on the high-pressure medium branch and a second pressure sensor disposed on the low-pressure medium branch; the locking valve includes a first locking valve and a second locking valve disposed on the high-pressure medium branch and the low-pressure medium branch, respectively.

[0014] In some embodiments, the wireless acquisition box also integrates a clock chip and a storage chip. The wireless acquisition box is configured to enter a local blind test buffer mode by using the clock chip and the storage chip when the wireless transmission module loses communication with the wireless receiving module.

[0015] In some embodiments, the mobile test bench includes a control compartment, a valve and pipeline compartment, and a power compartment. The control system and industrial panel device are embedded in the control compartment, the shared pipeline network and the control valve group are located in the valve and pipeline compartment, and the vacuum pump is located in the power compartment.

[0016] In some embodiments, the outer wall of the mobile test bench is also provided with a cable reel for storing external power supply cables.

[0017] In some embodiments, the mobile test bench is further provided with a storage compartment for accommodating the detachable pipeline within its frame structure.

[0018] In some embodiments, the outer shell of the wireless acquisition box is provided with a portable handle and a permanent magnet adsorption block for magnetically fixing the wireless acquisition box to the surface of the vehicle body, and the wireless acquisition box also integrates a portable rechargeable battery pack.

[0019] Secondly, the present invention also provides an integrated testing method for a rail vehicle air conditioning system, executed by the integrated testing device for a rail vehicle air conditioning system as described in the first aspect, the method comprising: The mobile test bench is controlled to fill the air conditioning system with high-pressure nitrogen through the shared pipeline network. After the set pressure is reached, the locking valve on the wireless acquisition box is closed. The wireless acquisition box is connected to the air conditioning system through a docking terminal. The second end of the shared main pipe of the mobile test bench is connected to the input end of the medium passage of the wireless acquisition box through a detachable pipeline. During the movement of the wireless acquisition box with the vehicle, the original pressure value is dynamically compensated and corrected based on the real-time temperature change sent by the wireless transmission module, and the air tightness of the air conditioning system is obtained based on the corrected pressure value; wherein, the detachable pipeline is disconnected from the wireless acquisition box, so that the wireless acquisition box is mounted on the rail vehicle and moves with the vehicle.

[0020] In some embodiments, obtaining the airtightness of the air conditioning system based on the corrected pressure value includes: The pressure decay rate and pressure decay acceleration are obtained from the corrected actual pressure holding curve. The air tightness fault diagnosis type of the air conditioning system is obtained based on the matching results of the pressure decay rate, the pressure decay acceleration, and the preset failure mode feature library.

[0021] In some embodiments, after obtaining the airtightness of the air conditioning system based on the corrected pressure value, the method further includes: The rail vehicle is moved back to the mobile test bench, the detachable pipeline is reconnected, the locking valve is opened, the shared pipeline network is switched to the vacuum branch, and the air conditioning system is vacuumed using the vacuum pump.

[0022] In some embodiments, after obtaining the air tightness of the air conditioning system based on the corrected pressure value, before performing a vacuum test on the air conditioning system using the vacuum pump, the method further includes: The valves on the common main pipe near the air conditioning system are kept closed, and the nitrogen supply branch and exhaust branch are opened. The residual pressure difference of the nitrogen source is used to directionally reverse flush the non-condensable gas or refrigerant oil adsorbed from the air conditioning system in the common main pipe to the external exhaust port.

[0023] In some embodiments, after performing a vacuum test on the air conditioning system using the vacuum pump, the method further includes: The system controls the shared pipeline network to switch to the charging branch, and uses the electronic scale to measure the external refrigerant charging bottle in real time, so as to charge the refrigerant into the air conditioning system in a quantitative manner.

[0024] In some embodiments, the process of metering refrigerant into the air conditioning system specifically includes: When the electronic scale detects that the added weight has reached the preset target total filling amount, it implements pulse width modulation duty cycle control on the first valve on the filling branch until the preset target total filling amount is reached.

[0025] This invention integrates the nitrogen source, vacuum pump, external refrigerant charging bottle, and exhaust port seamlessly into a single shared piping network by installing a control valve group at the first end of the shared main pipe of the mobile test bench. This avoids the cumbersome operations of frequently changing pipes and repeatedly disassembling and reassembling interfaces required by conventional solutions for pressure holding equipment, vacuum pumps, and charging machines, significantly reducing labor intensity and interface wear. The introduction of the shared main pipe reduces the number of bends and joints inside the equipment, lowering the potential leakage probability from a topological perspective and ensuring the overall sealing reliability of the equipment. The device is divided into a heavy-duty mobile test bench and a lightweight wireless acquisition box, with detachable piping connecting the two ends. This allows them to work collaboratively when fluidly connected and to operate independently when physically disconnected. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a three-dimensional structural schematic diagram of an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention; Figure 2 This is a front view structural diagram of the mobile test bench in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the connection of the shared pipeline network in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention; Figure 4 This is a front view structural diagram of the wireless acquisition box in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the power distribution area of ​​the mobile test bench in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention; Figure 6 This is a side view of one side of the mobile test bench in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention; Figure 7 This is a front view structural diagram of the valve pipeline compartment in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention; Figure 8 This is a side view of the other side of the mobile test bench in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention. Figure 9 This is a flowchart illustrating an integrated testing method for a rail vehicle air conditioning system provided in an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this 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 this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] Figure 1This is a three-dimensional structural schematic diagram of an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention. Figure 2 This is a front view structural diagram of the mobile test bench in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the connection of the shared pipeline network in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention. Figure 4 This is a front view structural diagram of the wireless acquisition box in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of the power distribution area of ​​the mobile test bench in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention.

[0030] Combination Figures 1 to 5 The integrated test device for the air conditioning system of rail vehicles includes a mobile test bench 1 and a wireless acquisition box 9. The mobile test bench 1 includes a control system, a vacuum pump 2, an electronic scale 4 for supporting an external refrigerant charging bottle 3, and a shared pipeline network 5. The shared pipeline network 5 includes a shared main pipe 6. The first end of the shared main pipe 6 is connected to an external nitrogen source 7, the suction port of the vacuum pump 2, the refrigerant charging bottle 3, and the exhaust port 8 through different control valve groups. The wireless acquisition box 9 is a physically separate structure independent of the mobile test bench 1, including a medium passage 60, a pressure sensor 10, and a wireless transmission module 11. The second end of the shared main pipe 6 is connected to the input end of the medium passage 60 through a detachable pipeline. The output end of the medium passage 60 is provided with a docking terminal for connecting to the pipeline interface of the air conditioning system 12. The medium passage 60 is provided with a locking valve for locking the pipeline pressure. The control system includes a controller 13 and a wireless receiving module 14. The controller 13 communicates with the wireless transmission module 11 through the wireless receiving module 14 for bidirectional wireless sensing data communication.

[0031] Specifically, the integrated testing device for rail vehicle air conditioning systems refers to a specialized testing tool for rail transit equipment that integrates multiple testing functions such as pressure holding, vacuuming, and refrigerant quantitative charging, and can achieve high-efficiency operation through a split physical structure. Mobile test bench 1, refer to... Figure 1 and Figure 2The term "control system" refers to a mobile, heavy-duty physical platform or base within an integrated testing device, responsible for centralized control, power supply, and the storage and measurement of large quantities of media. The "control system" is a core control unit composed of hardware circuits, communication modules, and a microprocessor, used to receive external sensor data, execute internal control logic, and send drive commands to various control valves and power components. The "vacuum pump 2" refers to a vacuum fluid machine used to remove gas from the air conditioning system 12 of a rail vehicle, enabling the system to reach the set vacuum level. The "electronic scale 4" is a gravity-sensing measuring instrument installed on the mobile testing platform 1, specifically used for real-time, high-precision weighing and feedback of weight changes in the external refrigerant charging bottle 3. The "external refrigerant charging bottle 3" refers to an external pressure vessel containing high-pressure liquid or gaseous refrigerant, which is placed on the electronic scale 4 as a consumable.

[0032] Shared pipeline network 5, such as Figure 3 As shown, this refers to a multi-channel fluid transport network arranged on the mobile test bench 1, which uses valve groups to switch between different main pipelines to transport different gaseous or liquid media. The shared main pipeline 6 refers to the main fluid channel in the shared pipeline network 5 that runs through multiple processes and connects key upstream and downstream control nodes. The control valve group refers to a collection of controlled valves connected in series or parallel on various fluid branches, used to cut off, connect, or regulate the direction and flow rate of the medium. The wireless acquisition box 9, as shown... Figure 4 As shown, this refers to a portable, physically separate compartment that is completely independent of the mobile test bench 1 in terms of physical structure, can be moved with a vehicle, and has a medium conduction channel, sensing and acquisition functions, and wireless communication functions. The medium passage 60 refers to an internal sealed fluid channel opened or laid inside the wireless acquisition box 9 for the passage of fluid media such as nitrogen or refrigerant. The pressure sensor 10 refers to a sensing element installed on the medium passage 60 inside the wireless acquisition box 9, used to sense and output the absolute or relative pressure electrical signal of the medium in the pipeline in real time.

[0033] The wireless transmission module 11 refers to the communication chip and antenna network integrated inside the wireless acquisition box 9, used to transmit the acquired sensor electrical signals via radio frequency waves. The detachable pipeline refers to the flexible or rigid long fluid transport pipe located between the mobile test bench 1 and the wireless acquisition box 9, which can be quickly and manually connected or disconnected as needed for the process. The docking terminal refers to the quick-connect connector terminal located on the external output end of the wireless acquisition box 9, capable of achieving a standard mechanical seal docking with the test valve port of the rail vehicle air conditioning system 12. The locking valve refers to the control valve installed on the internal medium passage 60 of the wireless acquisition box 9, specifically used to physically shut off and lock the fluid pressure inside the output pipeline. Controller 13, such as... Figure 5 As shown, this refers to the programmable logic controller (PLC) within the control system, responsible for the computing power support and signal processing of the overall machine's operating logic. Wireless receiver module 14, as shown... Figure 5As shown, it refers to a radio receiving device installed on the mobile test bench 1, hard-wired connected to the control system, specially used for receiving radio frequency signals transmitted by the wireless transmission module 11 and transmitting data to the controller 13.

[0034] When an air conditioner is installed on a vehicle for the first time or after maintenance, the following tests need to be completed in sequence after the refrigerant pipe is connected to the air conditioner: The first test is a pressure holding test. Nitrogen is charged from the high-pressure or low-pressure interface of the refrigerant pipe, and timing for pressure holding starts after the set pressure is reached. If the pressure drop value is within the set range within the specified time, the pipeline air tightness can be considered qualified, and the next step of vacuuming can be carried out. The second test is a vacuuming test. Connect the vacuum pump 2 to the high and low pressure interfaces of the refrigerant pipe, extract the air in the refrigerant pipe, and enter the refrigerant charging link when the vacuum degree meets the requirements. The third step is refrigerant charging: charge the refrigerant from the refrigerant charging cylinder into the refrigerant pipeline, monitor the charging amount in real time through the electronic scale 4, and stop charging after the set value is reached. During each test, sensors and pressure transmitters transmit real-time data to the upper computer system, realizing real-time display of parameters such as pressure holding, vacuum degree and refrigerant charging amount, ensuring that the test accuracy meets the requirements of actual vehicle use.

[0035] in combination with Figures 1 to 5 , when the integrated test device for a rail vehicle air conditioning system works, the mobile test bench 1 is connected to the wireless acquisition box 9 through detachable pipelines. The external nitrogen source 7, the suction port of the vacuum pump 2, the external refrigerant charging cylinder 3 placed on the electronic scale 4, and the atmospheric exhaust port 8 are respectively connected to the control valve group, and the control valve group is arranged at the first end of the common main pipe 6. When a specific process needs to be performed, the controller 13 controls the corresponding valve in the control valve group to open. For example, when charging nitrogen, the external nitrogen source 7 is opened, and high-pressure nitrogen flows through the first end of the common main pipe 6 into the common main pipe 6 and flows out from the second end of the common main pipe 6. Then, the high-pressure nitrogen passes through the detachable pipeline and enters the input end of the medium passage 60 of the wireless acquisition box 9, flows through the medium passage 60, and is finally injected into the pipeline interface of the rail vehicle air conditioning system 12 through the docking terminal on the output end of the medium passage 60 under the monitoring of the pressure sensor 10. In this process, the pressure sensor 10 inside the wireless acquisition box 9 collects pressure signals in real time, the wireless transmission module 11 modulates the pressure signals into high-frequency radio frequency signals and transmits them, and the wireless receiving module 14 on the mobile test bench 1 receives the radio frequency signals, demodulates them and transmits them to the controller 13, so that the controller 13 can monitor the fluid pressure state of the whole system in real time and realize two-way wireless sensor data communication.

[0036] Therefore, this embodiment of the invention, by setting a control valve group at the first end of the common main pipe 6 of the mobile test bench 1, seamlessly integrates the nitrogen source 7, vacuum pump 2, external refrigerant charging bottle 3, and exhaust port 8 onto the same common pipeline network 5. This avoids the cumbersome operations of frequently changing pipelines and repeatedly disassembling and reassembling interfaces required by conventional solutions for pressure holding equipment, vacuum pumps, and charging machines, significantly reducing labor intensity and interface wear. The introduction of the common main pipe 6 reduces the number of bends and joints inside the equipment, lowering the potential leakage probability from a topological perspective and ensuring the overall sealing reliability of the equipment. The device is divided into a heavy-duty mobile test bench 1 and a lightweight wireless acquisition box 9, with both ends connected by detachable pipelines, allowing them to work collaboratively when fluidly connected and to operate independently after physical disconnection.

[0037] In some embodiments, during a pressure holding test, the locking valve is closed to lock the high-pressure nitrogen gas within the air conditioning system 12, and the detachable piping is disconnected from the wireless acquisition box 9 so that the wireless acquisition box 9 can move with the vehicle.

[0038] Specifically, the pressure holding test refers to the process of filling the air conditioning system 12 of the rail vehicle with high-pressure nitrogen at a set pressure and monitoring its pressure change within a specified time to determine whether there are any micro-leakages in the system. The vehicle-mounted movement refers to the entire process of the wireless acquisition box 9 being directly mounted or placed on the rail vehicle body with the rail vehicle completely disconnected from the mobile test bench 1 via physical piping, and moving or being transferred with the rail vehicle within the test depot to other non-test tracks.

[0039] When the test procedure enters the pressure holding test stage, the mobile test bench 1 first injects high-pressure nitrogen gas at a preset pressure into the rail vehicle air conditioning system 12 through the shared main pipe 6, detachable pipeline, and medium passage 60. After inflation, the locking valve on the wireless acquisition box 9 is manually or automatically closed. At this time, the locking valve completely cuts off the high-pressure nitrogen gas and firmly locks it within the output end, docking terminal, and internal pipeline space of the rail vehicle air conditioning system 12 of the wireless acquisition box 9. Next, the test personnel physically disconnect the detachable pipeline from the input end of the medium passage 60 of the wireless acquisition box 9. At this time, there is no mechanical or fluid physical connection between the mobile test bench 1 and the wireless acquisition box 9. The rail vehicle can then be driven away, the wireless acquisition box 9 is mounted on the rail vehicle and moves with it, while the mobile test bench 1 remains on the original track or is pushed away to serve the next train.

[0040] Therefore, since the locking valve implements local locking pressure at the wireless acquisition box 9 and the detachable pipeline can be removed at any time, the time that the mobile test bench 1 occupies the vehicle during the pressure holding test is reduced to the inflation time. During the pressure holding period of several hours, the rail vehicle can be moved away from the core test track, and the wireless acquisition box 9 moves with the vehicle and performs wireless pressure holding monitoring at any location. At the same time, the mobile test bench 1 can be immediately put into the inflation or refueling operation of the next rail vehicle, which increases the utilization rate of the test depot track and the turnover efficiency of the mobile test bench 1 by several times.

[0041] In some embodiments, the wireless acquisition box 9 also includes, for example, Figure 3 The temperature sensor TEM1 shown is used to dynamically compensate and correct the original pressure value collected by the pressure sensor 10 based on the real-time temperature change fed back by the temperature sensor TEM1, and to obtain the air tightness of the air conditioning system 12 based on the corrected pressure value.

[0042] Specifically, the temperature sensor TEM1 refers to the sensing element integrated on the wireless acquisition box 9, used to sense the absolute temperature of the surface of the measured object and the fluid in real time and convert it into an electrical signal output. The raw pressure value refers to the current real-time surface pressure reading measured and output by the pressure sensor 10 directly based on physical deformation or piezoelectric effect without any mathematical model or environmental algorithm correction. Dynamic compensation correction refers to the process by which the controller 13 uses the real-time acquired temperature variables, substitutes them into a preset physical mathematical model of the gas state equation, calculates in real time and eliminates spurious pressure fluctuations caused by thermal expansion and contraction, restoring the true pressure value under isothermal conditions. Air tightness refers to the sealing performance level of the pipeline network of the rail vehicle air conditioning system 12 to prevent internal media from leaking to the external environment.

[0043] During the pressure holding test, the temperature sensor TEM1 and pressure sensor 10 inside the wireless acquisition box 9 continuously operate, transmitting the original pressure value and real-time temperature change through the wireless transmission module 11. The controller 13 inside the mobile test bench 1 remotely receives this data through the wireless receiving module 14 and uses an internally programmed algorithm to dynamically compensate and correct the original pressure value collected by the pressure sensor 10 based on the real-time temperature change. Finally, the airtightness of the rail vehicle's air conditioning system 12 is determined based on the corrected pressure value, i.e., the true isothermal pressure after eliminating temperature interference.

[0044] Therefore, by setting a temperature sensor TEM1 to obtain real-time temperature changes, and having the controller 13 perform reverse dynamic compensation correction, the pressure disturbance caused by the thermal expansion and contraction of the fluid is completely eliminated, ensuring that the airtightness determination result obtained by the controller 13 has extremely high certainty and authenticity no matter what temperature environment the vehicle moves to.

[0045] In some embodiments, the temperature sensor TEM1 includes a temperature probe extending outward from the housing of the wireless acquisition box 9.

[0046] Specifically, the temperature probe refers to the physical contact structure at the end of the temperature sensor TEM1 that directly exchanges heat with the surface of the object being measured and internally contains a high-sensitivity thermistor or thermocouple. The housing of the wireless acquisition box 9 refers to the rigid protective shell that surrounds the wireless acquisition box 9 to protect the internal circuit boards and battery from external dust and impacts. The temperature sensor TEM1 extends structurally, with its core temperature-sensing end protruding from the outer surface of the housing of the wireless acquisition box 9 as the temperature probe. This allows the temperature probe to overcome the spatial obstruction of the acquisition box housing and directly perform touch temperature measurement on external components.

[0047] Therefore, in this embodiment of the invention, the temperature sensor TEM1 is configured as a temperature probe extending outward from the housing of the wireless acquisition box 9, reducing the large delay and high thermal resistance in the heat transfer path. Built-in temperature sensing elements would face a longer time lag due to the outer insulation layer and the stagnant air layer inside the housing. At the same time, the outward-extending temperature probe structure allows the temperature sensing contact to face directly to the outside, which is beneficial for the controller 13 to instantly capture sudden local temperature changes.

[0048] In some embodiments, the wireless acquisition box 9 is fixed to the outer wall of the pipe of the air conditioning system 12 by a fixing structure provided on its housing surface, so that the temperature probe is attached to the surface of the low-pressure pipe of the air conditioning system 12 to obtain the real-time temperature of the fluid in the pipe being measured.

[0049] Specifically, the fixed structure refers to the physical connection component located on the outer shell of the wireless acquisition box 9, used to provide mechanical fastening or adsorption force. The outer wall of the pipeline refers to the external metal surface of the copper or steel pipes of the rail vehicle air conditioning system 12 exposed to the air. The low-pressure pipeline surface refers to the outer metal surface of the fluid pipeline of the rail vehicle air conditioning system 12 located on the evaporation pressure side.

[0050] The temperature sensor TEM1 is not simply suspended inside the sealed shell of the wireless acquisition box 9, but is specifically configured as a physical temperature probe extending outward from the shell of the wireless acquisition box 9. When the wireless acquisition box 9 is physically fixed to the outer wall of the pipeline of the rail vehicle air conditioning system 12 by a fixing structure provided on its shell surface, such as a strong magnetic adsorption block or a snap-fit ​​mechanism, the mechanical clamping force or magnetic force provided by the fixing structure forces the outwardly extending temperature probe to adhere tightly to the surface of the low-pressure pipeline of the air conditioning system 12 with extremely high surface contact stress. At this time, since the heat of the fluid inside the low-pressure pipeline is directly conducted to the temperature probe through the metal pipe wall, the temperature sensor TEM1 can directly obtain the real-time temperature of the fluid inside the measured pipeline through the temperature probe.

[0051] Therefore, if the temperature sensor TEM1 is built into the shell of the wireless acquisition box 9, it actually measures the temperature of the air inside the wireless acquisition box 9, which is insulated and stagnant by the shell. This temperature reading differs significantly from the actual fluid temperature inside the pipeline of the rail vehicle's air conditioning system 12 due to a significant phase transition hysteresis and impedance. This embodiment of the invention establishes an ultra-low thermal resistance direct conduction path from the internal fluid to the metal pipe wall and then to the temperature sensor by extending the temperature probe outwards and ensuring its tight attachment, thus guaranteeing instantaneous temperature response. The temperature probe is tightly attached to the surface of the low-pressure pipeline. Utilizing the sealing of the contact surface and the shielding provided by the shell of the wireless acquisition box 9, interference from external gusts of wind and internal convective air is eliminated, preventing cold or hot air convection interference to the sensor. This ensures that the temperature probe senses the core temperature of the pipeline fluid, guaranteeing the absolute accuracy of the data source for dynamic temperature compensation correction from a hardware structure perspective.

[0052] In some embodiments, such as Figure 3 As shown, the shared pipeline network 5 also includes a charging branch connected to the refrigerant charging bottle 3, a vacuuming branch connected to the suction port of the vacuum pump 2, a nitrogen supply branch connected to the external high-pressure nitrogen source 7, and an exhaust branch connected to the atmospheric exhaust port 8. The first end of the shared main pipe 6 is connected in parallel to the charging branch, the vacuuming branch, the nitrogen supply branch, and the exhaust branch.

[0053] Specifically, the shared pipeline network 5 refers to the integrated network located inside the mobile test bench 1, used for time-sharing and multiplexing of pipelines to achieve the transportation of multiple media. The filling branch, vacuum branch, nitrogen supply branch, and exhaust branch refer to four functional fluid pipeline branches with independent process functions connected in parallel at the first end of the shared main pipeline 6. The shared main pipeline 6 refers to the main fluid channel in the shared pipeline network 5 that runs through multiple test procedures and is directly connected to external detachable pipelines. The first end of the shared main pipeline 6 refers to the fluid inlet terminal of the shared main pipeline 6 near each control valve group, used for the parallel switching of multiple branch connections.

[0054] Inside the mobile test bench 1, the filling branch, vacuum branch, nitrogen supply branch, and exhaust branch are configured in parallel. The media pipelines of these four independent functional branches converge at the first end of the common main pipe 6 and are connected in parallel to the first end of the common main pipe 6. The common main pipe 6 extends straight forward within the valve pipeline compartment 16, and its second end extends out of the test bench to connect to detachable pipelines. When the controller 13 issues a command to drive different control valve groups to operate, different branches are activated, and the fluid medium is then transported via the common main pipe 6 in a time-division multiplexing manner.

[0055] Therefore, in this embodiment of the invention, the first end of the common main pipe 6 is connected in parallel to the charging branch, the vacuuming branch, the nitrogen supply branch, and the exhaust branch, forming a clear, unbranched, single-flow fluid topology. This parallel flow architecture allows the experimental device to process four different media processes in a time-sharing manner using a single main pipe. Since all branches are connected in parallel at the first end, the fluid flow paths do not intersect, avoiding local fluid dead zones and resistance losses at bends caused by the crisscrossing pipelines in conventional multi-path systems. This reduces the pressure drop during gas transmission and is beneficial for achieving a higher vacuum maintenance state under low-pressure vacuuming branches.

[0056] In some embodiments, the control valve group includes a first valve YV1 connected in series with the charging branch, a second valve YV2 connected in series with the nitrogen supply branch, a third valve DDF connected in series with the vacuum branch, and a fourth valve YV3 connected in series with the exhaust branch.

[0057] Specifically, the charging branch, vacuum branch, nitrogen supply branch, and exhaust branch refer to four functional fluid pipeline branches with independent process functions connected in parallel at the first end of the common main pipe 6. The first valve YV1, the second valve YV2, the third valve DDF1, and the fourth valve YV3 refer to solenoid valves or electric ball valves that are connected in series on the above four fluid branches and are driven by the electrical signal of the controller 13 to achieve full opening or full closing.

[0058] The common main pipe 6 has a clearly defined first end and second end. Its first end is physically split into four parallel branches: a charging branch, a vacuuming branch, a nitrogen supply branch, and an exhaust branch. Each branch has a corresponding control valve connected in series. The specific fluid flow control principle is as follows: When performing gas charging and pressure holding, the controller 13 outputs a drive signal to close the first valve YV1, the third valve DDF1, and the fourth valve YV3, while simultaneously fully opening the second valve YV2 connected in series on the nitrogen supply branch. Nitrogen from the high-pressure nitrogen source 7 flows into the first end of the common main pipe 6 via the nitrogen supply branch and is then transported to the second end. When performing a vacuum test, the controller 13 closes the second valve YV2, the first valve YV1, and the fourth valve YV3, and opens the third valve DDF1 connected in series on the vacuuming branch, allowing the vacuum pump 2's suction port to connect to the common main pipe 6 through the vacuuming branch. When performing quantitative charging, the controller 13 opens the first valve YV1, and the other valves close. The refrigerant in the refrigerant bottle enters the common main pipe 6 via the charging branch. When pressure relief and gas exhaust are required, the fourth valve YV3 is opened separately, and the gas is discharged to the atmosphere through the exhaust branch.

[0059] Therefore, this embodiment of the invention sets up the valve group and four functional branches in a topology of parallel connection at the first end, clearly defining the correspondence between the first valve YV1, the second valve YV2, the third valve DDF1, and the fourth valve YV3, which are connected in series at a single point on their respective branches. This avoids dead zones or gas leakage caused by complex cross-connection. Since the four branches share the first end of the main pipe 6, the controller 13 only needs to interact with simple single-open and three-closed logic electrical signals to isolate different media at the hardware fluid level, ensuring the fluid safety of the overall control network.

[0060] In some embodiments, such as Figure 3 As shown, the medium passage 60 includes a high-pressure medium branch 61 and a low-pressure medium branch 62 that are independent of each other. The input terminals of the high-pressure medium branch 61 and the low-pressure medium branch 62 are connected in parallel to serve as the input terminals of the medium passage 60. The output terminals of the high-pressure medium branch 61 and the low-pressure medium branch 62 are respectively connected to a first docking terminal and a second docking terminal, which are used as docking terminals. The first docking terminal and the second docking terminal are used to connect to the high-pressure port and the low-pressure port of the air conditioning system 12, respectively.

[0061] Specifically, medium passage 60 refers to the sealed main channel opened or laid inside the wireless acquisition box 9 for guiding the flow of test fluid. High-pressure medium branch 61 and low-pressure medium branch 62 refer to two parallel fluid channels inside the wireless acquisition box 9, each with different pressure resistance and flow characteristics. Input end and output end refer to the combined inlet end and separate outlet end of the high-pressure and low-pressure medium branches in the direction of fluid flow. First docking terminal and second docking terminal refer to the mechanical terminals located at the ends of high-pressure medium branch 61 and low-pressure medium branch 62, respectively, for physical docking with the high-pressure test valve port of the air conditioning system 12, such as the condenser side and the low-pressure test valve port, such as the evaporator side. High-pressure pipe port and low-pressure pipe port refer to the standard maintenance pipe physical interfaces of the rail vehicle air conditioning system 12, located on the high-pressure side and low-pressure side of the refrigeration cycle, respectively.

[0062] When fluid flows from the detachable conduit to the input end of the media passage 60 of the wireless acquisition box 9, it immediately splits into two parallel sub-paths at the input end: a high-pressure media branch 61 and a low-pressure media branch 62. Each of these branches has an independent mechanical interface at its output end, namely a first mating terminal and a second mating terminal. In actual testing, the first and second mating terminals are tightly connected to the high-pressure and low-pressure ports of the rail vehicle's air conditioning system 12, respectively.

[0063] Therefore, in this embodiment of the invention, the input ends of the high-pressure medium branch 61 and the low-pressure medium branch 62 are connected in parallel, and the output ends are respectively connected to the first docking terminal and the second docking terminal, forming a dual-sided symmetrical control structure. The internal structure of the rail vehicle air conditioning system 12 is divided into two sub-circuits, high pressure and low pressure, by an expansion valve. Through the dual-sided shunting design of this embodiment, test gas can be injected or extracted simultaneously from both the high-pressure port and the low-pressure port. Since the channels are symmetrical and parallel, the pressure build-up rates of the fluids on both sides are similar, thereby greatly reducing the single-sided pressure blockage and single-sided measurement blind zone caused by the throttling impedance of the expansion valve inside the air conditioner due to single-sided gas filling, and improving the overall test uniformity of the air conditioning system 12.

[0064] In some embodiments, the pressure sensor 10 includes a first pressure sensor BP1 disposed on the high-pressure medium branch 61 and a second pressure sensor BP2 disposed on the low-pressure medium branch 62; the locking valve includes a first locking valve and a second locking valve disposed on the high-pressure medium branch 61 and the low-pressure medium branch 62, respectively.

[0065] Specifically, the first pressure sensor BP1 and the second pressure sensor BP2 are respectively hard-wired and installed on the high-pressure medium branch 61 and the low-pressure medium branch 62, independently monitoring the real-time pressure on both sides. The first lock-up valve and the second lock-up valve are respectively arranged on the high-pressure medium branch 61 and the low-pressure medium branch 62, used as shut-off components for locking the pressure of the branch.

[0066] On the high-pressure medium branch 61, the first pressure sensor BP1 senses the internal pressure changes in real time, and the first locking valve is responsible for cutting off or opening the high-pressure passage. On the low-pressure medium branch 62, the second pressure sensor BP2 senses the internal pressure changes in real time, and the second locking valve is responsible for cutting off or opening the low-pressure passage. During the pressure holding test, the first and second locking valves close simultaneously, locking the nitrogen in the high-pressure and low-pressure sections into the corresponding cavities of the air conditioning system 12, respectively.

[0067] Therefore, this embodiment of the invention, by introducing a symmetrical design of a high-pressure medium branch 61 and a low-pressure medium branch 62 within the wireless acquisition box 9, enables simultaneous monitoring of the high-pressure and low-pressure sides inside the air conditioning system 12 via the first pressure sensor BP1 and the second pressure sensor BP2. This allows pressure holding and vacuum testing to be performed simultaneously on both sides, greatly improving the fluid conduction rate and eliminating measurement blind spots. Through independent control of the first and second locking valves, even if the throttle valve inside the air conditioning system 12 is completely closed or blocked, the pressure on the high-pressure and low-pressure sides can be firmly locked in their respective pipelines, ensuring that no gas overflows from either the high-pressure or low-pressure side when the detachable pipeline is removed.

[0068] Figure 6This is a side view of one side of the mobile test bench in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention. Figure 6 As shown, the exterior of the mobile test bench can also be equipped with a three-color indicator light 22, a nitrogen inlet, a high-pressure port 24, a low-pressure port 25, and an exhaust outlet. The three-color indicator light 22 is used to display different test states, the nitrogen inlet is used to connect to a nitrogen cylinder, the high-pressure port 24 is used to connect to the high-pressure port of the vehicle being measured, the low-pressure port 25 is used to connect to the low-pressure port of the vehicle being measured, and the exhaust outlet discharges the test gas.

[0069] In some embodiments, the wireless acquisition box also integrates a clock chip and a storage chip. The wireless acquisition box is configured to enter a local blind test buffering mode when the communication between the wireless transmission module and the wireless receiving module is lost, utilizing the clock chip and the storage chip. Sensing data is continuously collected by pressure and temperature sensors, and the clock chip timestamps the sensing data before continuously storing it in the storage chip. The wireless transmission module is configured to trigger a resume transmission command when the wireless acquisition box re-establishes the wireless communication connection, packaging and sending the timestamped sensing data packets buffered in the storage chip to the controller.

[0070] Specifically, a clock chip refers to an electronic timing component integrated inside the wireless acquisition box, used to provide a time reference and real-time time information. A storage chip refers to a non-volatile semiconductor storage medium integrated inside the wireless acquisition box, used to permanently store digital data without data loss after power failure. Communication disconnection refers to the state of radio signal blockage or data link interruption between the wireless transmission module and the wireless receiving module due to spatial shielding, long-distance cross-channel interference, or electromagnetic interference. Local blind test buffer mode refers to a high-reliability operating mode that the wireless acquisition box automatically switches to after a wireless communication disconnection, independently performing signal acquisition locally and temporarily storing the data in the internal storage chip. Sensor data refers to the set of current real-time pressure and temperature signals collected by the pressure and temperature sensors described in the above embodiments. A timestamp refers to a digital time stamp generated by the clock chip and attached to each set of sensor data to mark the precise time when the data was generated. A breakpoint resume transmission command refers to a control mechanism automatically triggered by the system after the wireless communication link is restored to normal operation, used to package and transmit back the historical sensor data packets accumulated in the local storage chip in chronological order. A sensor data packet refers to a fluid maintenance data set formed by framing and packaging multiple sets of time-stamped sensor data according to a specific network communication protocol.

[0071] During the long-term offline pressure monitoring process performed by the wireless acquisition box 9 along with the rail vehicle, the wireless transmission module 11 periodically performs a communication handshake with the wireless receiving module 14 on the mobile test bench 1 side. When the rail vehicle moves to the shielded blind zone of the large steel structure maintenance workshop due to scheduling needs, or when the distance exceeds the radio frequency coverage range due to cross-depot shunting, the communication between the wireless transmission module 11 and the wireless receiving module 14 will be interrupted. Once the communication link is determined to be interrupted, the wireless acquisition box 9, based on local control, automatically calls the internal clock chip and storage chip to enter the local blind test buffer mode. In this local blind test buffer mode, the pressure sensor 10 and temperature sensor TEM1 located inside the split box maintain normal working status, continuously collecting the current fluid pressure and pipe wall temperature to form sensor data. The microprocessor inside the wireless acquisition box 9 calls the clock chip in real time to configure a digital time stamp accurate to the millisecond level for each set of sensor data as a timestamp, and then continuously stores the timestamped sensor data into the internal storage chip for local latching.

[0072] When the rail vehicle returns to the wireless radio frequency coverage area of ​​the mobile test bench 1, or when the external strong interference disappears, the wireless transmission module 11 and the wireless receiving module 14 re-establish wireless communication connection. At this time, the control system automatically triggers a breakpoint resume command and remotely sends it to the wireless acquisition box 9. In response to the breakpoint resume command, the wireless transmission module 11 sequentially reads the historical sensor data with timestamps accumulated and cached during the communication disconnection period from the storage chip, packages it into standardized sensor data packets according to the timing logic, and centrally transmits it via radio waves to the wireless receiving module 14 on the mobile test bench 1 side, and finally uploads it to the controller 13, so that the controller 13 can supplement and obtain all historical test trajectories during the offline period.

[0073] Therefore, this invention overcomes the signal interruption and packet loss defects during the offline shunting and pressure holding process of rail vehicles, ensuring the continuity of the pressure holding curve. The pressure holding test process of rail vehicles usually lasts for several hours. When moving with the rail vehicle in the large rail maintenance depot area, it is difficult to avoid frequent wireless communication disconnections caused by building shielding. Once traditional wireless equipment encounters a signal interruption, the data during the disconnection period will be completely lost, causing the pressure holding test to fail due to data discontinuity, and it is necessary to repeat the inflation and pressure holding process, which takes several hours. This invention, by setting a clock chip and a storage chip and configuring a local blind test buffer mode, enables the wireless acquisition box 9 to autonomously enter the local blind test latching state during the disconnection period. When the wireless link restores the wireless communication connection, the breakpoint resume transmission command is used to centrally dump the historical sensor data packets with timestamps back to the controller 13. The controller 13 can use its internal timing differential alignment logic to accurately reassemble and seamlessly stitch this offline historical data with the current real-time online data along the time axis according to the timestamp, maintaining the integrity of the entire long-term test data chain.

[0074] Furthermore, this embodiment of the invention avoids false positive leakage alarms caused by temporary signal interruptions. In traditional wireless monitoring schemes, if data is momentarily lost, the control backend may determine the data is abnormal or directly trigger a leakage alarm due to data interruption if it does not receive the latest pressure data. This embodiment of the invention configures an on-site caching and retransmission mechanism with timestamps, enabling the controller 13 to clearly identify the true time evolution slope of pressure attenuation after receiving the retransmitted sensor data packets. This helps to effectively distinguish it from sudden network physical packet loss, preventing false alarms caused by communication link interruptions and improving the overall operational stability and environmental adaptability of the system.

[0075] Figure 7 This is a front view structural diagram of the valve pipeline compartment in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention. Combined with... Figures 1 to 7 The mobile test bench 1 includes a control compartment 15, such as... Figure 7 The valve and piping compartment 16 shown and as follows Figure 2 The power compartment 17 shown, the control system and industrial panel device 18 are embedded in the control compartment 15, the common piping network 5 and the control valve group are located in the valve piping compartment 16, and the vacuum pump 2 is located in the power compartment 17.

[0076] Specifically, the control compartment 15, valve and pipeline compartment 16, and power compartment 17 refer to three independent physical installation compartments with different functions, which are divided into three separate structures on the overall frame of the mobile test bench 1 by physical partitions or spatial layering. The industrial panel device 18 refers to a comprehensive interactive panel installed on the outside of the equipment, integrating a human-machine interface touch screen, manual operation buttons, status indicator lights, etc., for test personnel to input commands and observe data.

[0077] The control compartment 15 is located above the mobile test bench 1 or on a top layer for easy operation. The control system and industrial panel device 18 are embedded within this control compartment 15 to provide spatial isolation from the high-voltage and high-impact environment. The aforementioned shared piping network 5 and various control valve groups are all neatly and securely arranged within the valve piping compartment 16, facilitating piping routing and valve testing. Figure 2 As shown, the power chamber 17 is located at the bottom of the mobile test bench 1. Heavy power components such as the vacuum pump 2 and the base of the electronic scale 4 that carries the steel cylinder are all firmly fixed inside the power chamber 17.

[0078] Therefore, the vacuum pump 2 and the filling cylinder are the heaviest heavy components in the entire machine, while the control board and industrial panel device 18 are extremely lightweight. By placing the vacuum pump 2 and other components in the lowest power compartment 17, the physical center of gravity of the entire mobile test bench 1 is kept extremely low. When the equipment is rapidly pushed or subjected to lateral collisions on uneven train test pits or trackside roads, the extremely low center of gravity can generate anti-overturning moment, reducing the risk of accidents such as equipment tipping over and injuring test personnel or damaging train skirts. The separate compartmentalization of the control compartment 15, valve and pipeline compartment 16, and power compartment 17 completely physically isolates the high-precision, low-voltage controller 13 and industrial panel device 18 from the fluid valves that are at risk of leakage, as well as the vacuum pump 2 that experiences strong vibration and heat dissipation. This effectively prevents crosstalk between the controller 13 signal and the strong electromagnetic interference from the motor, thus extending the mean time between failures (MTBF) of the electronic components.

[0079] Figure 8 This is a side view of the other side of the mobile test bench in an integrated test device for a rail vehicle air conditioning system provided in an embodiment of the present invention. (Combined with...) Figures 1 to 8 The outer wall of the mobile test bench 1 is also equipped with a storage compartment for external power cables. Figure 8 The cable reel 19 shown, and the frame structure of the mobile test bench 1 also have a storage compartment for storing detachable pipelines.

[0080] Specifically, cable reel 19 refers to a mechanical reel mounted on the outer shell of the mobile test bench 1, equipped with a coiling spring or manual rocker arm, capable of automatically or manually rotating and winding long external power supply cables for storage. Storage compartment refers to a drawer-type or door-type storage compartment located within the frame of the mobile test bench 1, providing physical storage volume. When the mobile test bench 1 is not in operation, or when it is being moved between test tracks, long external power supply cables that were originally exposed and dragged on the ground are manually or mechanically wound onto the cable reel 19 fixed to the outer wall of the test bench, tightly winding them around the outside of the frame. Simultaneously, detachable tubing, several meters long and already removed from the wireless acquisition box 9, is manually coiled and then neatly inserted into the specially designed storage compartment within the frame structure of the mobile test bench 1 for storing detachable tubing.

[0081] Therefore, in the busy and complex environment of a rail transit track test warehouse, long cables and fluid hoses scattered and dragging on the ground are easily tripped up by walking test workers or crushed by other moving test trolleys. This invention addresses this by using a cable reel 19 and a storage compartment to neatly store power cables and detachable pipes as a whole, making the entire test device a compact unit without redundant external attachments during relocation, thus eliminating safety hazards. The storage compartment for detachable pipes prevents them from being worn down or broken due to severe friction, impact, or compression during equipment movement, ensuring the safety of fluid transmission during high-pressure filling processes.

[0082] In some embodiments, such as Figure 4 As shown, the wireless acquisition box 9 has a portable handle 20 on its outer shell and a permanent magnet adsorption block for magnetically fixing the wireless acquisition box 9 to the surface of the vehicle body. The wireless acquisition box 9 also integrates a portable rechargeable battery pack 21.

[0083] Specifically, the portable handle 20 refers to an ergonomically designed mechanical handle fixed to the top of the wireless acquisition box 9's outer shell, designed for single-handed gripping and extraction by the test personnel. The permanent magnet adsorption block refers to a block of strongly magnetic material embedded or fixed to the back or bottom of the wireless acquisition box 9's outer shell, capable of generating a persistent strong magnetic field. The vehicle body surface refers to the outer surface of the steel structure or ferromagnetic metal plate of the rail vehicle's exterior. The portable rechargeable battery pack 21 refers to a lithium battery or nickel-metal hydride battery module integrated inside the wireless acquisition box 9's shell, capable of repeated charging and discharging and independently supplying stable DC power to the sensors and wireless transmission module 11 within the box.

[0084] When the rail vehicle completes inflation and is ready to be disconnected and driven away to enter the on-board pressure monitoring process, the test personnel lift the wireless acquisition box 9 from its initial position by holding the portable handle 20 on the outer shell with one hand. Then, the test personnel directly attach the wireless acquisition box 9 to the side surface of the rail vehicle. Relying on the strong magnetic attraction generated by the permanent magnet adsorption blocks on the outer shell, the wireless acquisition box 9 is firmly magnetically fixed to the surface of the vehicle without any bolts or external supports, and moves with the vehicle. During the on-board movement and pressure maintenance period, which lasts for several hours, all the electronic components inside the wireless acquisition box 9, such as the pressure sensor 10, the temperature sensor TEM1, and the wireless transmission module 11, are powered entirely by the portable rechargeable battery pack 21 integrated inside the wireless acquisition box 9, without any external wiring.

[0085] Therefore, drilling, welding, and other destructive modifications are absolutely prohibited on the surface of the rail vehicle. This invention utilizes the strong magnetic adsorption properties of permanent magnet adsorption blocks to achieve second-level non-destructive adsorption and removal of the wireless acquisition box 9 on the vehicle surface. It is also necessary to ensure that the wireless acquisition box 9 remains stable and does not slip when the vehicle is swaying at low speeds within the depot. The built-in portable rechargeable battery pack 21 eliminates the constraints of low-voltage communication and power cables, making the wireless acquisition box 9, after being hung on the vehicle surface, an independent operating node completely decoupled from the outside world in terms of electricity, fluid dynamics, and mechanics, ensuring the smooth implementation of the on-board pressure monitoring procedure.

[0086] For example, combined Figure 1 and Figure 2 The mobile testing platform 1 also includes a keyboard 27, a mouse storage area 28, an electronic scale display 29, and buttons 30. The electronic scale display 29 shows the real-time values ​​of the scale. Buttons 30 include an emergency stop button for use in emergencies; a power switch for controlling the entire system; and a manual / automatic knob for switching between manual and automatic modes. The mobile testing platform 1 also includes a printer 31 and an industrial computer 32. The printer 31 is used for printing test reports, and the industrial computer 32 is the control system for the testing platform. Figure 4 As shown, the wireless acquisition box 9 is also equipped with a corresponding conduit interface 33. For example... Figure 5 As shown, the power distribution area of ​​the mobile test bench also includes a circuit breaker 34, a rail-mounted socket 35, an AC contactor 36, a DC24V switching power supply 37, a switch 38, an intermediate relay 3, and a terminal block 40. The circuit breaker controls the on / off state of the power circuit; the rail-mounted socket supplies power to the industrial computer, monitor, printer, etc.; the AC contactor protects the vacuum pump and control circuit; the DC24V switching power supply provides DC24V power to the control circuit; the switch is used for communication between the industrial computer and the controller; the intermediate relay drives the solenoid valve; and the terminal block is used for connecting input and output signals. Figure 7 As shown, the valve and pipeline compartment is also equipped with a filter 41, an electric ball valve 42, and a solenoid valve. The filter is used to filter impurities in the gas from the filling bottle, the electric ball valve is used to control the opening and closing of the test gas path, and the solenoid valve is used to control the opening and closing of the test gas path. Figure 8 As shown, on the other side of the mobile test bench, there are also load switches 44, power plugs 45, and non-marking rubber wheels 46. The load switch is used to control the total power supply for the test, and the power plug adopts an aviation plug for quick connection.

[0087] Figure 9 This is a schematic flowchart of an integrated testing method for a rail vehicle air conditioning system provided in an embodiment of the present invention. The integrated testing method for a rail vehicle air conditioning system can be performed by the integrated testing device for a rail vehicle air conditioning system provided in this embodiment of the invention. Figure 9 As shown, the integrated test method for the air conditioning system of rail vehicles includes the following steps: S101. Control the mobile test bench to fill the air conditioning system with high-pressure nitrogen through a shared pipeline network. After reaching the set pressure, close the locking valve on the wireless acquisition box. The wireless acquisition box is connected to the air conditioning system through a docking terminal. The second end of the shared main pipe of the mobile test bench is connected to the input end of the medium passage of the wireless acquisition box through a detachable pipeline.

[0088] S102. During the movement of the wireless acquisition box with the vehicle, the original pressure value is dynamically compensated and corrected based on the real-time temperature change sent by the wireless transmission module, and the air tightness of the air conditioning system is obtained based on the corrected pressure value; wherein, the detachable pipeline is disconnected from the wireless acquisition box, so that the wireless acquisition box is mounted on the rail vehicle and moves with the vehicle.

[0089] Specifically, the mobile test bench 1 is controlled to inject high-pressure nitrogen into the air conditioning system 12 through the shared pipeline network 5. The controller 13 issues a control command to open the corresponding valve, driving the fluid from the high-pressure nitrogen source 7 to be injected into the train's air conditioning system through the test bench pipeline network. The wireless pressure monitoring step refers to the process step in which the wireless acquisition box 9 continuously collects data and remotely monitors airtightness via wireless transmission while the detachable pipeline is disconnected and the system moves with the vehicle.

[0090] First, the wireless acquisition box 9 is connected to the pipeline interface of the rail vehicle's air conditioning system 12 via its output terminal. The second end of the common main pipe 6 of the mobile test bench 1 is connected to the input end of the medium passage 60 of the wireless acquisition box 9 via a detachable pipeline. Then, the controller 13 issues a command to switch the common pipeline network 5 of the mobile test bench 1 to nitrogen supply mode, charging high-pressure nitrogen into the air conditioning system 12. When the pressure sensor 10 detects that the internal pressure of the system reaches the preset pressure holding threshold, the locking valve on the wireless acquisition box 9 is manually or automatically closed, firmly locking the high-pressure nitrogen in the air conditioning system 12 and the output end of the wireless acquisition box 9. Subsequently, the detachable pipeline is disconnected from the input end of the wireless acquisition box 9, and the rail vehicle starts and drives away. The wireless acquisition box 9, mounted on the surface of the vehicle body, moves with the vehicle, releasing the current test track. During the vehicle's movement, the pressure sensor 10 and temperature sensor TEM1 of the wireless acquisition box 9 collect data in real time. The real-time temperature change and the original pressure value are transmitted back to the test bench through the wireless transmission module 11. The controller 13 in the test bench remotely receives these sensor data and performs dynamic compensation and correction on the original pressure value in the background based on the real-time temperature change. Based on the corrected pressure value, the air tightness of the air conditioning system 12 is directly obtained and determined.

[0091] In some embodiments, obtaining the air tightness of the air conditioning system based on the corrected pressure value includes: obtaining the pressure decay rate and pressure decay acceleration based on the corrected actual pressure holding curve; and obtaining the air tightness fault diagnosis type of the air conditioning system based on the matching results of the pressure decay rate, pressure decay acceleration, and a preset failure mode feature library.

[0092] Specifically, the true holding pressure curve refers to the pure pressure characteristic curve, after being filtered out by the controller 13 to remove temperature disturbances, reflecting the pressure change of the internal medium of the air conditioning system 12 under isothermal conditions over time. The pressure decay rate refers to the rate of change of pressure over time at the current moment, obtained by the controller 13 through first-order differential calculation of the true holding pressure curve; it corresponds to the first derivative. The pressure decay acceleration refers to the rate of change of pressure over time at the current moment, obtained by the controller 13 through second-order differential calculation of the true holding pressure curve; it corresponds to the second derivative. The preset failure mode feature library refers to the set of feature matrices pre-stored in the controller 13, representing the slope of pressure changes caused by different mechanical faults such as gasket wear or spring fatigue during leakage. The airtightness fault diagnosis type refers to the fault conclusion automatically identified and output by the system, indicating the specific mechanical damage cause leading to the air conditioning leak.

[0093] During the determination phase, controller 13 acquires the actual pressure holding curve. Controller 13 runs its internal fault diagnosis program, calling a differential algorithm to perform a first-order numerical derivative of the actual pressure holding curve along the time axis to obtain the pressure decay rate, and a second-order numerical derivative to obtain the pressure decay acceleration. Subsequently, the diagnosis program performs matching and identification between the feature vector composed of this pressure decay rate and pressure decay acceleration and the feature data stored in a preset failure mode feature library. When the calculated matching coefficient exceeds a set threshold, the system automatically identifies and outputs the airtightness fault diagnosis type of the air conditioning system 12, for example, directly displaying on the interface that the air conditioning system is not airtight due to gasket wear.

[0094] Therefore, this invention embodiment performs first- and second-order numerical differential identification based on the actual pressure holding curve, and matches it with a feature library to output the fault diagnosis type, enabling the integrated testing device to possess intelligent data analysis and reasoning capabilities. In microscopic leakage fluid mechanics, the media escape behavior caused by different failure mechanisms has its fixed functional characteristics. Leakage caused by aging and wear of the sealing gasket usually exhibits constant damping and slow decay, with the first derivative being stable and the second derivative approaching zero. In contrast, leakage caused by foreign particles stuck in gaps exhibits a high initial pressure drop followed by a rapid convergence in the middle and later stages as the pressure difference decreases, with the first derivative showing obvious nonlinear characteristics. This invention embodiment extracts these features through first- and second-order numerical differentiation, achieving insight into the causes of air conditioning faults. It can guide targeted improvements to the maintenance process within the section, avoiding the shortcomings of conventional simple pass / fail judgments that lack guidance for process optimization.

[0095] In some embodiments, after obtaining the air tightness of the air conditioning system 12 based on the corrected pressure value, the method further includes: moving the rail vehicle back to the side of the mobile test bench 1, reconnecting the detachable pipeline, opening the locking valve, controlling the common pipeline network 5 to switch to the vacuum branch, and performing a vacuum test on the air conditioning system 12 using the vacuum pump 2.

[0096] Specifically, the vacuuming step refers to the step of, after the pressure-holding monitoring is finished, re-dispatching the train back to the side of the mobile test bench 1, and reconnecting the fluid pipelines to perform the high-vacuum degree evacuation process. After the rail vehicle has completed wireless pressure-holding monitoring for several hours and its air tightness is determined as qualified by the controller 13, the shunting system re-dispatches the rail vehicle back to the side of the mobile test bench 1. The test personnel re-take the detachable pipeline, and physically reconnect its first end and second end to the mobile test bench 1 and the wireless acquisition box 9 respectively. Subsequently, the operator manually opens the shut-off valve on the wireless acquisition box 9, at this time, the controller 13 outputs an instruction to control the shared pipeline network 5 on the mobile test bench 1 to cut off the nitrogen supply circuit, switch and open the vacuuming branch, the vacuum pump 2 in the power compartment 17 is fully started, and through the vacuuming branch, the shared main pipe 6, the detachable pipeline and the medium passage 60 of the wireless acquisition box 9, the residual nitrogen and trace water molecules inside the rail vehicle air conditioning system 12 are forcibly extracted and discharged at high vacuum degree, and a vacuuming test is performed.

[0097] Thereby, by reconnecting the detachable pipeline and opening the shut-off valve, the embodiment of the present invention instantly restores the fluid communication channel between the mobile test bench 1 and the rail vehicle air conditioning system 12, enabling the equipment to seamlessly and rapidly switch from the off-line on-vehicle pressure-holding state back to the on-line vacuuming process, and maintaining the coherence of the integrated test. Through the powerful extraction by the vacuum pump 2, not only the nitrogen filled in the previous process is completely discharged, but also the trace moisture adsorbed inside the air conditioning pipeline is promoted to vaporize under low pressure and be extracted by using the high vacuum environment, which clears the barrier for the subsequent charging of high-quality refrigerant.

[0098] In some embodiments, after obtaining the air tightness of the air conditioning system 12 according to the corrected pressure value and before performing the vacuuming test on the air conditioning system 12 through the vacuum pump 2, the method further comprises: controlling the valve on the shared main pipe 6 close to the side of the air conditioning system 12 to keep closed, and controlling to open the nitrogen supply branch and the exhaust branch, and using the residual pressure difference of the nitrogen source 7 to perform directional reverse flushing of non-condensable gas adsorbed from the air conditioning system 12 or refrigeration oil inside the shared main pipe 6 to the external exhaust port 8.

[0099] Specifically, self-cleaning purging refers to a self-cleaning process that uses the pressure difference of the nitrogen source 7 to reversely blow the main pipeline inside the device to remove deposited oil and impurities. Non-condensable gas refers to gas that cannot be condensed into liquid under the working temperature and pressure of the air conditioning system 12, such as air and residual nitrogen. Refrigeration oil refers to special lubricating oil for lubricating the moving parts of the compressor of the rail vehicle air conditioning system 12, which is easy to overflow with the gas flow and deposit in the test pipeline.

[0100] After the pressure holding test is completed and during the process interval before switching the system to the reconnection vacuuming step, controller 13 initiates the self-cleaning purging control logic. First, it controls the fourth solenoid valve YV4, the second electric ball valve DDF2, and the third electric ball valve DDF3 on the common main pipe 6, which are closest to the rail vehicle air conditioning system 12, to remain closed, thereby completely cutting off the physical connection with the atmosphere inside the air conditioning system 12. Next, controller 13 controls the opening of the second solenoid valve YV2 on the nitrogen supply branch and the third solenoid valve YV3 on the exhaust branch. At this time, high-pressure nitrogen from the external high-pressure nitrogen source 7 is injected into the first end of the common main pipe 6. Since the passage to the train air conditioning is closed, the high-pressure nitrogen is forced to form a violent reverse flow in the common main pipe 6 under the pressure difference drive. It carries non-condensable gas or residual refrigerant oil that may be drawn back from the air conditioning system 12 into the common main pipe 6, rushing in the reverse direction at full speed towards the exhaust branch, and finally being discharged into the external environment through the atmospheric exhaust port 8.

[0101] Therefore, during the pre-pressurization or routine test pipe removal, trace amounts of refrigerant oil or non-condensable gases containing moisture are often drawn back into the air conditioning system 12 and adhere to the inner wall of the common main pipe 6. If not removed, these residual impurities will be directly drawn into the vacuum pump 2 or flushed back into the train's air conditioning system by the new refrigerant during subsequent vacuuming and refrigerant charging, leading to a decrease in refrigerant purity. This embodiment of the invention cleverly utilizes the residual pressure difference of high-pressure nitrogen to perform directional reverse flushing during process breaks by closing valves close to the air conditioning side and opening nitrogen supply and exhaust. This thoroughly cleans the adhered refrigerant oil and non-condensable gases before they enter the vacuum and charging processes, ensuring extreme self-cleanliness of the entire main pipe network. Reverse pulse purging avoids long-term accumulation and carbonization of refrigerant oil at the solenoid valve core and electric ball valve seals, protecting the mechanical sensitivity of the control valve assembly and reducing maintenance costs.

[0102] In some embodiments, after the air conditioning system 12 is vacuumed by the vacuum pump 2, the method further includes: controlling the common pipeline network 5 to switch to the charging branch, using the electronic scale 4 to measure the external refrigerant charging bottle 3 in real time, and quantitatively charging the refrigerant into the air conditioning system 12.

[0103] Specifically, the quantitative charging step refers to the process of precisely adding a specific mass of liquid refrigerant into the rail vehicle air conditioning system 12 after vacuuming. Weight reduction measurement refers to the weighing method where the electronic scale 4 monitors the total mass reduction of the external refrigerant charging bottle 3 in real time and calculates the actual net mass of the refrigerant that has flowed out and been injected into the train's air conditioning system. After the vacuuming test is passed, the controller 13 cuts off the vacuuming branch and controls the shared pipeline network 5 to fully switch to the charging branch, i.e., controls the opening of the first valve YV1. At this time, the liquid refrigerant inside the external refrigerant charging bottle 3, under its own saturated vapor pressure, flows from the charging branch into the shared main pipe 6, and begins quantitative charging into the rail vehicle air conditioning system 12 through the detachable pipeline and wireless acquisition box 9. During this period, the electronic scale 4 located at the bottom of the power compartment 17 of the mobile test bench 1 is in a high-frequency real-time weighing state, continuously collecting and feeding back dynamic weight reduction data of the external refrigerant charging bottle 3 to the controller 13. The controller 13 compares the current charged mass with the set target charging amount in real time through this weight reduction measurement method until the quantitative charging requirement is met.

[0104] Therefore, the entire process requires no replacement of any external physical piping. It relies solely on the internal electrical signal switching of the control valve group within the controller 13 to instantly transition from a high-vacuum state to a high-precision refrigerant charging state, significantly reducing auxiliary process time. The use of a high-precision electronic scale 4 for weight reduction measurement ensures that the external refrigerant charging bottle 3 is firmly supported on the scale 4's surface. The mass reduction during fluid outflow is a direct, linear physical variable, unaffected by changes in fluid temperature, density, or air bubbles. This provides higher anti-interference capability and true-value accuracy compared to conventional volumetric flow meters.

[0105] In some embodiments, the process of quantitatively charging refrigerant into the air conditioning system 12 specifically includes: when the electronic scale 4 detects that the amount of refrigerant added has reached the preset target total charge amount, pulse width modulation duty cycle control is implemented on the first valve on the charging branch until the set target total charge amount is reached.

[0106] Specifically, the preset proportion of the target total charge volume refers to the quality stage value corresponding to a conversion inflection point percentage, which is preset according to the standard total charge volume required by the rail vehicle air conditioning system 12. Pulse width modulation duty cycle control means that the controller 13 does not drive the valve through a continuous normally open signal, but instead outputs a high-frequency continuous pulse waveform to make the valve enter a high-frequency open-close-open-close pulse micro-creep approximation state.

[0107] At the beginning of the quantitative charging step, the first valve YV1 on the charging branch is continuously open, and the refrigerant is injected at full speed and high flow rate under a large pressure difference. When the electronic scale 4 in the power compartment 17 detects that the weight loss of the external refrigerant charging bottle 3 has reached a preset proportion, such as 90% of the set target total charge, the controller 13 immediately adjusts the output waveform and implements pulse width modulation duty cycle control on the first valve YV1 on the charging branch. At this time, the first valve YV1 is no longer normally open, but begins to switch between high-frequency intermittent pulses, for example, opening for 0.1 seconds and closing for 0.2 seconds, and the refrigerant flow rate instantly switches from a torrent state to a droplet-like approach state. The electronic scale 4 continuously monitors the weight change until the weight loss reaches the set target total charge, at which point the controller 13 issues a final value lockout signal, the first valve YV1 is completely closed, and the charging is completed.

[0108] Therefore, during the high-pressure refrigerant charging process, the fluid has extremely high flow velocity and kinetic energy within the detachable pipeline and common main pipe 6, which are several meters long. If the first valve YV1 is suddenly closed only after charging to 100% at full speed, the mechanical closing of the valve will cause a response delay, and the fluid that has already generated kinetic energy inside the pipeline will continue to flow into the air conditioning system 12 due to its huge flow inertia, directly resulting in a serious overcharge of the final actual charging amount. This embodiment of the invention introduces pulse width modulation duty cycle control at a preset ratio to instantly cut off the large flow rate and reduce it to an extremely small pulse average flow rate. In this state, the kinetic energy and flow inertia of the fluid are almost zero. When the set target total charging amount is finally reached and the valve is completely closed, the extra charging amount caused by overcharge is close to zero, avoiding the risk of low air conditioning cooling efficiency or compressor liquid slugging damage caused by overcharging or undercharging.

[0109] In summary, this invention integrates multiple functions into one unit, capable of simultaneously performing pressure holding tests, vacuum tests, refrigerant charging tests, and manual operations, thus solving the problems of limited functionality and fragmented testing processes in existing equipment. Utilizing automated control technology, it achieves automatic operation of the testing process, automatic data acquisition, automatic result uploading, and automatic generation of test reports, reducing human intervention and improving testing accuracy and efficiency. It possesses excellent versatility and adaptability, meeting the testing needs of air conditioning systems in different vehicle models, and its parameters can be flexibly set, expanding its applicability. Equipped with a comprehensive safety protection mechanism, it automatically stops operation and alarms in case of abnormalities, ensuring the safety of equipment and operators. It enables information management of test data, supporting historical data query, traceability, and report printing, contributing to the standardization of the testing process. It can address the issue of long pressure holding times by employing wireless communication between the data acquisition device and the test bench, solving the problem of the vehicle being unable to move during the pressure holding process.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated test device for a rail vehicle air conditioning system, characterized in that, include: The mobile test bench includes a control system, a vacuum pump, an electronic scale for carrying an external refrigerant charging bottle, and a shared pipeline network. The shared pipeline network includes a shared main pipe, the first end of which is connected to an external nitrogen source, the suction port of the vacuum pump, the refrigerant charging bottle, and the exhaust port through different control valve groups. The wireless acquisition box is a physically separate structure independent of the mobile test bench, including a medium passage, a pressure sensor, and a wireless transmission module; wherein, the second end of the common main pipe is connected to the input end of the medium passage through a detachable pipe, the output end of the medium passage is provided with a docking terminal for connecting to the air conditioning system pipe interface, and the medium passage is provided with a locking valve for locking the pipe pressure. The control system includes a controller and a wireless receiving module. The controller communicates bidirectionally with the wireless transmission module via the wireless receiving module to transmit sensor data.

2. The integrated test device for rail vehicle air conditioning system according to claim 1, characterized in that, During the pressure holding test, the locking valve is closed to lock the high-pressure nitrogen gas within the air conditioning system, and the detachable pipeline is disconnected from the wireless acquisition box so that the wireless acquisition box can move with the vehicle.

3. The integrated test device for rail vehicle air conditioning system according to claim 2, characterized in that, The wireless acquisition box also includes a temperature sensor. The controller is used to dynamically compensate and correct the original pressure value collected by the pressure sensor based on the real-time temperature change fed back by the temperature sensor, and obtain the air tightness of the air conditioning system based on the corrected pressure value.

4. The integrated test device for rail vehicle air conditioning system according to claim 3, characterized in that, The temperature sensor includes a temperature probe extending outward from the housing of the wireless acquisition box.

5. The integrated test device for rail vehicle air conditioning system according to claim 4, characterized in that, The wireless acquisition box is fixed to the outer wall of the air conditioning system's pipes via a fixing structure on its housing surface, so that the temperature probe is attached to the surface of the low-pressure pipes of the air conditioning system to obtain the real-time temperature of the fluid in the pipes being measured.

6. The integrated test device for rail vehicle air conditioning system according to any one of claims 1-5, characterized in that, The shared pipeline network also includes a charging branch connected to the refrigerant charging bottle, a vacuum branch connected to the vacuum pump intake port, a nitrogen supply branch connected to an external high-pressure nitrogen source, and an exhaust branch connected to the atmospheric exhaust port. The first end of the shared main pipe is connected in parallel to the charging branch, the vacuum branch, the nitrogen supply branch, and the exhaust branch.

7. The integrated test device for rail vehicle air conditioning system according to claim 6, characterized in that, The control valve group includes a first valve connected in series in the charging branch, a second valve connected in series in the nitrogen supply branch, a third valve connected in series in the vacuum branch, and a fourth valve connected in series in the exhaust branch.

8. The integrated test device for rail vehicle air conditioning system according to any one of claims 1-5, characterized in that, The medium passage includes a high-pressure medium branch and a low-pressure medium branch that are independent of each other. The input ends of the high-pressure medium branch and the low-pressure medium branch are connected in parallel to serve as the input end of the medium passage. The output ends of the high-pressure medium branch and the low-pressure medium branch are respectively connected to a first docking terminal and a second docking terminal, which are used as docking terminals. The first docking terminal and the second docking terminal are used to connect to the high-pressure port and the low-pressure port of the air conditioning system, respectively.

9. The integrated test device for rail vehicle air conditioning system according to claim 8, characterized in that, The pressure sensor includes a first pressure sensor disposed on the high-pressure medium branch and a second pressure sensor disposed on the low-pressure medium branch; the locking valve includes a first locking valve and a second locking valve disposed on the high-pressure medium branch and the low-pressure medium branch, respectively.

10. The integrated test device for rail vehicle air conditioning system according to any one of claims 1-5, characterized in that, The wireless acquisition box also integrates a clock chip and a storage chip. The wireless acquisition box is configured to enter a local blind test buffer mode when the wireless transmission module and the wireless receiving module lose communication.

11. The integrated test device for rail vehicle air conditioning system according to any one of claims 1-5, characterized in that, The mobile test bench includes a control compartment, a valve and pipeline compartment, and a power compartment. The control system and industrial panel device are embedded in the control compartment, the shared pipeline network and the control valve assembly are located in the valve and pipeline compartment, and the vacuum pump is located in the power compartment.

12. The integrated test device for rail vehicle air conditioning system according to any one of claims 1-5, characterized in that, The outer wall of the mobile test bench is also equipped with a cable reel for storing external power supply cables.

13. The integrated test device for rail vehicle air conditioning system according to any one of claims 1-5, characterized in that, The mobile test bench also has a storage compartment inside its frame structure for storing the detachable pipelines.

14. The integrated test device for rail vehicle air conditioning system according to any one of claims 1-5, characterized in that, The wireless acquisition box has a portable handle on its outer shell and a permanent magnet adsorption block for magnetically fixing the wireless acquisition box to the surface of the vehicle body. The wireless acquisition box also integrates a portable rechargeable battery pack.

15. An integrated test method for a rail vehicle air conditioning system, characterized in that, Performed by the integrated test apparatus for rail vehicle air conditioning systems as described in any one of claims 1-14, the method includes: The mobile test bench is controlled to fill the air conditioning system with high-pressure nitrogen through the shared pipeline network. After the set pressure is reached, the locking valve on the wireless acquisition box is closed. The wireless acquisition box is connected to the air conditioning system through a docking terminal. The second end of the shared main pipe of the mobile test bench is connected to the input end of the medium passage of the wireless acquisition box through a detachable pipeline. During the movement of the wireless acquisition box with the vehicle, the original pressure value is dynamically compensated and corrected based on the real-time temperature change sent by the wireless transmission module, and the air tightness of the air conditioning system is obtained based on the corrected pressure value; wherein, the detachable pipeline is disconnected from the wireless acquisition box, so that the wireless acquisition box is mounted on the rail vehicle and moves with the vehicle.

16. The integrated test method for a rail vehicle air conditioning system according to claim 15, characterized in that, The air tightness of the air conditioning system is obtained based on the corrected pressure value, including: The pressure decay rate and pressure decay acceleration are obtained from the corrected actual holding pressure curve. The air tightness fault diagnosis type of the air conditioning system is obtained based on the matching results of the pressure decay rate, the pressure decay acceleration, and the preset failure mode feature library.

17. The integrated test method for a rail vehicle air conditioning system according to claim 15, characterized in that, After obtaining the airtightness of the air conditioning system based on the corrected pressure value, the following steps are also included: The rail vehicle is moved back to the mobile test bench, the detachable pipeline is reconnected, the locking valve is opened, the shared pipeline network is switched to the vacuum branch, and the air conditioning system is vacuumed using the vacuum pump.

18. The integrated test method for a rail vehicle air conditioning system according to claim 17, characterized in that, After obtaining the air tightness of the air conditioning system based on the corrected pressure value, before performing a vacuum test on the air conditioning system using the vacuum pump, the following steps are also included: The valves on the common main pipe near the air conditioning system are kept closed, and the nitrogen supply branch and exhaust branch are opened. The residual pressure difference of the nitrogen source is used to directionally reverse flush the non-condensable gas or refrigerant oil adsorbed from the air conditioning system in the common main pipe to the external exhaust port.

19. The integrated test method for a rail vehicle air conditioning system according to claim 17 or 18, characterized in that, After performing a vacuum test on the air conditioning system using the vacuum pump, the process further includes: The system controls the shared pipeline network to switch to the charging branch, and uses the electronic scale to measure the external refrigerant charging bottle in real time, so as to charge the refrigerant into the air conditioning system in a quantitative manner.

20. The integrated test method for a rail vehicle air conditioning system according to claim 19, characterized in that, The process of metering refrigerant into the air conditioning system specifically includes: When the electronic scale detects that the added weight has reached the preset target total filling amount, it implements pulse width modulation duty cycle control on the first valve on the filling branch until the preset target total filling amount is reached.

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