Thermal fatigue testing device for airbags in positive pressure oxygen respirators

Abstract

This invention relates to the field of respiratory protection safety technology in coal mines, and discloses a thermal fatigue testing device for airbags in positive pressure oxygen respirators. The device includes a controller, an electrically heated water tank, a first temperature sensor, an inflation pump, a deflation pump, an electric valve, a second temperature sensor, a differential pressure sensor, a pressure relief valve, a detection air path, an airbag, and an alarm. The controller controls the inflation pump to inflate, the heated water tank to heat, and the deflation pump to evacuate, providing a stable and controllable heat source for the test platform. Simultaneously, it collects real-time data such as air pressure and temperature inside the airbag from the sensors, and maintains the set test pressure of the airbag by controlling the opening of the electric valve in conjunction with the deflation valve. It also provides real-time data for human-machine interaction and receives control and operation commands. This solution can simulate the real working environment of the airbag, realize automatic data acquisition, and thus achieve effective and rapid judgment of the airbag heat sealing process quality, improving testing efficiency and reducing testing costs.

Description

Technical Field

[0001] This invention relates to the field of respiratory protection safety technology in coal mines, specifically to a thermal fatigue detection device for airbags in positive pressure oxygen respirators. Background Technology

[0002] Positive pressure oxygen respirators are essential personal respiratory protective equipment for coal mine rescue workers operating in harsh environments with toxic or harmful gases or oxygen deficiency. The air bladder of a positive pressure oxygen respirator utilizes the flexibility of TPU material, allowing its volume to change according to the breathing gas pressure, thus achieving the gas storage function in the breathing cycle of the positive pressure oxygen respirator. The finished air bladder is manufactured using a high-frequency heat-sealing process, consisting of a TPU panel and TPU injection-molded connectors connecting the cleanroom canister, cooling box, self-closing valve, drain valve, and positive pressure plate. Because the air bladder of a positive pressure oxygen respirator operates under prolonged high-temperature gas and certain gas pressure conditions, the finished air bladder may have quality defects such as openings in the heat-sealed areas and cracks in the connectors, which will seriously affect the breathing safety of the user.

[0003] Currently, manufacturers of positive pressure oxygen respirators assemble pre-made airbags into the complete respirator unit for overall performance testing. This method is costly and inefficient. Furthermore, quality control departments lack specialized equipment for testing the thermal fatigue of airbags, making it impossible to effectively assess the quality of the airbag heat-sealing process and thus ensure the safety and reliability of the airbags when used with the positive pressure oxygen respirator. Summary of the Invention

[0004] The purpose of this invention is to provide a thermal fatigue testing device for airbags in positive pressure oxygen respirators. This device can simulate the real working environment of the airbags and automatically collect test data, thereby enabling effective and rapid judgment of the quality of the airbag heat sealing process. This ensures the safety and reliability of the airbags when used with positive pressure oxygen respirators, while also improving testing efficiency and reducing testing costs.

[0005] To achieve the above objectives, the present invention provides a thermal fatigue testing device for the airbag of a positive pressure oxygen respirator, comprising a controller, a hot gas supply device, and a thermal fatigue testing bench.

[0006] The hot air source supply device includes an electric heating water tank, a first temperature sensor, an air pump, a vacuum pump, and an electric valve; the electric heating water tank is equipped with a heating module; the temperature sensor is located inside the electric heating water tank.

[0007] The air inlet of the air pump is connected to the indoor air, the air outlet of the air pump is connected to the air inlet pipe of the electric heating water tank, the air outlet pipe of the electric heating water tank is connected to the air inlet of the vacuum pump, and the air outlet of the vacuum pump is connected to the air inlet of the electric valve.

[0008] The thermal fatigue testing bench includes a second temperature sensor, a differential pressure sensor, a pressure relief valve, a detection air path, an airbag, and an alarm. The air inlet of the detection air path is connected to the air outlet of the electric valve. The detection connection port of the detection air path is threadedly connected to the airbag sleeve nut fixedly connected to the airbag. The detection end of the second temperature sensor is threadedly connected to the upper part of the detection air path, and the detection port of the differential pressure sensor is connected to the airbag pressure sampling port. The air outlet of the detection air path is connected to the pressure relief valve.

[0009] The controller is electrically connected to the heating module, the first temperature sensor, the air pump, the vacuum pump, the electric valve, the second temperature sensor, the differential pressure sensor, and the alarm.

[0010] The principle and effect of this solution are as follows: In this solution, the controller is used to control the heating module to heat the water in the electric heating water tank, and the controller is used to detect the temperature of the water in the electric heating water tank through the first temperature sensor. The controller is used to control the air pump to inflate the electric heating water tank. When the first temperature sensor detects that the water in the electric heating water tank has reached the preset value, the controller controls the air pump to start, thereby extracting the hot air in the electric heating water tank. The corresponding hot air passes through the air pump, the detection air path, and the air bag in sequence, thereby inflating the air bag with hot air. In this way, a stable source of hot air can be provided for the air bag.

[0011] As the airbag inflates, the pressure inside increases. The controller uses a second temperature sensor and a differential pressure sensor to detect the temperature and pressure inside the airbag. When the preset test pressure is reached, the controller maintains this pressure by controlling the opening of the electric valve, while the pressure relief valve releases air at the set pressure. This ensures that the airbag maintains this pressure range for a certain period of time. The controller records the opening of the electric valve and the pressure range at this time. Subsequently, the controller continuously monitors the air pressure within the set detection time to see if it exceeds the recorded pressure range. If the air pressure drops and exceeds the preset detection pressure range, it is determined that there is a local rupture or opening in the heat-sealed part of the airbag, indicating a quality defect. The detection process is terminated early, the electric heating water tank, the inflation pump, and the deflation pump are turned off, and inflation into the airbag is stopped. When the controller determines that there is a local rupture or opening in the heat-sealed part of the airbag, it activates an alarm to alert quality inspectors to check for defective airbags.

[0012] Current technology for testing airbags typically involves assembling the finished airbag into the entire respirator for overall performance testing. This process is time-consuming, costly, and inefficient.

[0013] In this solution, a thermal fatigue testing device is used to simulate the actual working environment of the airbag. The controller sets and adjusts the pressure and temperature parameters to provide a stable and controllable heat source for airbag testing. This enables rapid and effective inspection of the airbag's process quality, reduces the scrap rate of the airbag, and improves the safety and reliability of the airbag when used with a positive pressure oxygen respirator. Ultimately, this ensures the breathing safety of respirator users and achieves the goals of improving testing efficiency and reducing testing costs.

[0014] The alarm system automatically notifies quality control personnel immediately when a defective airbag is detected. The defective airbag is then inspected, and the heat-sealing process parameters can be adjusted promptly based on the test results, thus preventing a large number of defective airbags from being produced.

[0015] Furthermore, the heating module includes multiple heating tubes, each of which is controlled by a controller.

[0016] Beneficial effects: The output of the heating element is controlled by a controller, which ensures that the heating element can be used for a long time and greatly improves the service life of the heating element.

[0017] Furthermore, the electric heating water tank is also equipped with an inlet valve and a water level sensor that are electrically connected to the controller; the inlet valve is located at the water inlet end of the outer wall of the electric heating water tank; and the water level sensor is located on the inner wall of the electric heating water tank.

[0018] Beneficial effects: The controller is used to detect the water level in the electric heating water tank through a water level sensor. The system is set with high water level thresholds and low water level thresholds. When the water level sensor detects that the electric heating water tank is at a low water level, the controller will activate the alarm and simultaneously control the inlet valve to open, thereby realizing automatic water replenishment in the electric heating water tank. When the water level sensor detects that the water in the electric heating water tank is at a high water level, it will control the inlet valve to close and stop water replenishment.

[0019] The water level in the electric heating water tank is automatically adjusted through the cooperation of a water level sensor and an inlet valve. This high degree of automation effectively saves manpower.

[0020] Furthermore, the alarm includes a buzzer and a warning light.

[0021] Beneficial effect: By providing dual alerts through sound and light, quality inspectors can be informed of alarm notifications.

[0022] Furthermore, an air-water separation device is installed between the air inlet of the air pump and the air outlet of the electric heating water tank.

[0023] Beneficial effects: The air-water separation device can separate water vapor from the hot air source, avoiding water accumulation in the airbag during the detection process, which would otherwise lead to inaccurate detection results.

[0024] Furthermore, the electric heating water tank includes a tank shell and a tank liner; the bottom of the tank liner is provided with a mounting slot for placing the heating tube, and a partition is also provided on the mounting slot; universal casters are provided at the four corners of the bottom of the tank shell.

[0025] Beneficial effects: In this solution, the electric heating water tank includes a tank shell and a tank liner. This double-layer design improves the heat preservation and insulation of the water tank. By setting an installation groove for the heating pipe at the bottom of the tank liner and isolating multiple heating pipes with a partition, a more stable and safe working environment is provided for the heating pipes.

[0026] Furthermore, the thermal fatigue testing bench also includes a testing platform, and the testing air path is installed on the testing platform through a fixed support base. The testing air path is provided with multiple testing connection ports for installing and connecting airbags, and the testing air path is wrapped with thermal insulation cotton.

[0027] Beneficial effects: In this design, the detection gas path has multiple detection connection ports, allowing for the simultaneous installation of multiple airbags to form an airbag group, greatly improving the efficiency of airbag detection. Furthermore, the detection gas path is wrapped with insulation cotton, ensuring the insulation effect of the delivered gas. Attached Figure Description

[0028] Figure 1 This is a logic block diagram of the thermal fatigue detection device for the airbag of a positive pressure oxygen respirator in Embodiment 1 of the present invention.

[0029] Figure 2 This is a schematic diagram of the thermal fatigue detection device for the airbag of a positive pressure oxygen respirator in Embodiment 1 of the present invention. Detailed Implementation

[0030] The following detailed description illustrates the specific implementation methods:

[0031] The markings in the accompanying drawings include: 1. Industrial control computer and human-machine interaction system; 2. Hot air source supply device; 3. Thermal fatigue testing bench; 11. Human-machine interaction device; 12. Industrial control computer; 13. Controller; 14. AC contactor; 15. Surge suppressor; 16. Relay; 17. Alarm; 18. Multi-channel data logger; 19. Operating console; 21. Electric heating water tank; 22. Circulating water pump; 23. First temperature sensor; 24. Water level sensor; 25. Heating tube; 26. Partition plate; 27. Universal casters; 28. Drain valve; 29. ​​Air inlet pipe; 210. Air inlet; 211. Air outlet pipe; 212. Gas-water separator; 213. Air pump; 214. Electric valve; 215. Water inlet valve; 216. Detection air path; 31. Testing platform; 32. Pressure relief valve; 33. Fixed support base; 34. Airbag; 35. Detection connection port; 36. Second temperature sensor; 37. Differential pressure sensor; 38.

[0032] Example 1:

[0033] Example 1 is basically as shown in the attached document. Figure 1 and Figure 2 As shown: A thermal fatigue testing device for the airbag of a positive pressure oxygen respirator includes a controller 13, a hot air source supply device 2, and a thermal fatigue testing test bench 3;

[0034] The hot air supply device 2 includes an electric heating water tank 21, a circulating water pump 22, a first temperature sensor 23, an air filling pump 210, an air extraction pump 214, and an electric valve 215. A heating module is installed inside the electric heating water tank 21. The first temperature sensor 23 is located inside the electric heating water tank 21. In this embodiment, the heating module includes multiple heating tubes 25, wherein the heating tubes 25 are made of 304 seamless stainless steel, and the heating tubes are controlled by a controller. In another embodiment, the heating module includes multiple heating tubes 25 and a relay 16, through which the heating tubes are controlled.

[0035] The air inlet 211 of the air pump 210 is connected to the indoor air, and the air outlet of the air pump 210 is connected to the air inlet pipe 29 of the electric heating water tank 21 to realize the inflation function; the air outlet pipe 212 of the electric heating water tank 21 is connected to the air inlet of the air-water separator 213, the air outlet of the air-water separator 213 is connected to the air inlet of the vacuum pump 214, and the air outlet of the vacuum pump 214 is connected to the air inlet of the electric valve 215.

[0036] The thermal fatigue testing bench 3 includes a fixed support 34, a testing platform 32, a second temperature sensor 37, a differential pressure sensor 38, a pressure relief valve 33, a testing gas path 31, an airbag 35, and an alarm 17. The testing gas path 31 is mounted on the testing platform 32 via the fixed support 34. The testing gas path 31 has multiple testing connection ports 36 for mounting and connecting the airbag 35. The testing gas path 31 is wrapped with insulation cotton to ensure the temperature of the injected gas. In this embodiment, the testing gas path 31 has three testing connection ports 36, dividing it into three branches: a first testing branch, a second testing branch, and a third testing branch. The testing connection port 36 on each branch is threadedly connected to the airbag sleeve nut fixed to the airbag. The second temperature sensor 37 is threadedly fastened to the upper part of the testing gas path 31, and the differential pressure sensor 38 is bolted to the side of the testing platform 32. The detection port of the differential pressure sensor 38 is connected to the pressure sampling port of the airbag 35. Each branch is equipped with a corresponding pressure relief valve 33. In this embodiment, the air path flows sequentially through the inflation pump 210, the electric heating water tank 21, the suction pump 214, the detection air path 31, the airbag 35, and the pressure relief valve 33. In this embodiment, each branch is equipped with a corresponding differential pressure sensor 38, airbag 35, and pressure relief valve 33, while the second temperature sensor 37 is located on the detection air path 31. Furthermore, in this embodiment, multiple airbags 35 are provided on each branch; specifically, in this embodiment, there are four airbags 35 on each branch, connected in series, with the last airbag 35 connected to the corresponding pressure relief valve 33 on that branch. This allows for simultaneous thermal fatigue testing of twelve airbags 35, significantly improving testing efficiency.

[0037] To monitor the water level in the electric heating water tank 21 and prevent it from gradually decreasing as heating progresses, thus preventing the tank and partition 26 from drying out, the electric heating water tank is equipped with an inlet valve 216, a water level sensor 24, and an alarm 17, all electrically connected to the controller 13. The inlet valve 216 is located on the water inlet end of the outer wall of the electric heating water tank 21 and is connected to an external water supply pipeline; the water level sensor 24 is located on the inner wall of the electric heating water tank 21. In this embodiment, the alarm 17 includes a buzzer and a warning light. To facilitate maintenance of the electric heating water tank 21, a drain valve 28 is also provided on the side wall of the electric heating water tank 21.

[0038] The controller 13 is electrically connected to the heating module, the first temperature sensor 23, the water inlet valve 216, the air pump 210, the air pump 214, the electric valve 215, the second temperature sensor 37, the differential pressure sensor 38, and the alarm 17.

[0039] The controller 13 is used to heat the water in the electric heating water tank 21 through the heating module and detect the temperature of the water in the electric heating water tank 21 through the first temperature sensor 23, thereby controlling the air pump 210 to inflate the electric heating water tank 21. When the first temperature sensor 23 detects that the water temperature in the electric heating water tank 21 reaches the preset water temperature value, it controls the air pump 214 to start, thereby extracting the hot air in the electric heating water tank 21. The extracted hot air passes through the electric valve 215, the detection air path 31 and the air bag 35 in sequence. The heating module of the electric heating water tank 21 is intermittently started and stopped to achieve the heating gas temperature, thereby realizing the hot air filling of the air bag 35 and providing a stable hot air source for the air bag 35.

[0040] As hot air is continuously injected, the pressure inside the airbag 35 increases. The controller 13 is used to detect the temperature and pressure inside the airbag 35 through the second temperature sensor 37 and the differential pressure sensor 38. When the air pump 214 continuously draws gas into the airbag 35, when the corresponding pressure reaches the preset pressure value, the controller 13 controls the opening of the electric valve 215 and the pressure relief valve 33 opens according to the set pressure, so that the pressure fluctuation inside the airbag 35 is maintained within the preset pressure value range for a period of time. At this time, the controller 13 will record the opening of the electric valve 215 and the pressure value range. Subsequently, the air pressure is continuously monitored within the set detection time to ensure it does not exceed the preset pressure range. If the air pressure drops and exceeds the preset detection pressure range, it is determined that the heat-sealed part of the airbag 35 has a local rupture, opening, or other quality defects, and the detection process is terminated early. The electric heating water tank 21, the inflation pump 210, and the deflator 214 are shut off to stop inflating the airbag 35. An alarm is triggered by the alarm device 17 to prompt quality inspectors to check the defective airbag 35. In this embodiment, the alarm device 17 includes a buzzer and a warning light, with the warning light being a red LED. The dual alert of sound and light ensures that quality inspectors receive the alarm reminder, promptly assess the situation, and address the defective airbag 35.

[0041] To monitor the water level in the electric heating water tank 21 and prevent the water level from gradually decreasing as heating continues (which would cause the heating element 25 to overheat the partition 26 and also be detrimental to the use of the electric heating water tank 21), the controller 13 uses a water level sensor 24 to detect the water level in the electric heating water tank 21. The system is set with high and low water level thresholds. When the water level sensor 24 detects that the electric heating water tank 21 is at a low water level, it controls the inlet valve 216 to open. In this embodiment, when the electric heating water tank 21 is detected to be at a low water level, the controller 13 will simultaneously activate the alarm 17. That is, in this embodiment, the corresponding alarm 17 can realize multiple alarms: first, the airbag 35 is not qualified; second, the electric heating water tank 21 is at a low water level. This enables automatic water replenishment in the electric heating water tank 21. When the water level sensor 24 detects that the water level in the electric heating water tank 21 is at a high water level, it controls the inlet valve 216 to close, stopping water replenishment. In this embodiment, a circulating water pump 22 is also provided in the electric heating water tank 21. By controlling the start and stop of the circulating water pump 22, the circulation in the electric heating water tank 21 is realized, so that the heating temperature of water and gas is more uniform.

[0042] This embodiment also includes a communication module electrically connected to the controller 13. Specifically, the communication module includes a wired communication module and a wireless communication module. The controller 13 is connected to a host computer via the communication module. The host computer includes an industrial control computer and a human-machine interface system 1, specifically an industrial control computer 12 and a human-machine interface device 11. To facilitate better operation of the host computer, it is fixed on the operating table 19. A multi-channel data logger 18 is also provided, which is connected to the second temperature sensor 37 and the differential pressure sensor 38 via a 20mA signal to monitor sensor data in real time. In this embodiment, the wired communication module mainly uses RS485 communication and transmits data using the Modbus protocol.

[0043] The controller 13 can be a microcontroller or a PLC. In this embodiment, a Siemens PLC module is used, specifically a Siemens 6ES7 288-1ST20-0AA1 PLC. The host computer, developed based on Siemens WINCC 7.4 configuration software, is installed on the industrial computer 12. The first temperature sensor 23, the second temperature sensor 37, and the pressure sensor are all three-wire types, with the pressure sensor having a range of 2 kPa and the temperature sensor having a range of 100°C.

[0044] In this embodiment, since the extracted gas is water vapor, in order to avoid water accumulation in the airbag 35 during the detection process, a gas-water separation device 213 is designed at the air inlet 211 of the air pump 214 to separate the water vapor in the hot gas. In this embodiment, the water separated by the gas-water separation device 213 can also be returned to the electric heating water tank 21 for recycling.

[0045] In this embodiment, the electric heating water tank 21 includes a tank shell and a tank liner. The bottom of the tank liner has an installation groove for placing the heating element 25, and a partition 26 is installed in the installation groove to provide a more stable and safe working environment for the heating element. Meanwhile, universal casters 27 are installed at the four corners of the bottom of the tank shell, enabling the water tank to be moved. These universal casters 27 also have a braking function, ensuring the stability of the electric heating water tank 21 after movement. In this embodiment, the dimensions of the tank liner are 1 x 0.5 x 0.5 m; effective volume: 0.25 m³. 3 It is made of double-layer 304 stainless steel. In this embodiment, insulation cotton is also sandwiched between the outer shell and the inner tank of the water tank, which makes the heat preservation effect of the electric heating water tank better.

[0046] Example 2

[0047] Compared with Embodiment 1, the difference in this embodiment is that: a solenoid valve is provided between the detection connection port 36 of the detection gas path 31 and the air bag 35, and a gas detection mechanism electrically connected to the controller 13 is provided on the side of the solenoid valve near the air bag 35.

[0048] In this scheme, the operator installs the corresponding airbag 35 onto the corresponding solenoid valve. Since there are multiple detection connection ports 36 on the detection air circuit 31, when the operator installs the airbag 35 onto the solenoid valve corresponding to the detection connection port 36, the corresponding solenoid valve will open. Thus, the solenoid valve corresponding to the air inlet end where the airbag 35 is installed is in the open state. Then, the controller 13 will control the vacuum pump 214 and the inflation pump 210 to start, filling the corresponding gas into the airbag 35. In this way, the solenoid valve corresponding to the air inlet end where the airbag 35 is installed can be vented. If the solenoid valve is not open, no gas flows through. The controller 13 is used to detect whether the solenoid valve is open through the gas detection mechanism, thereby detecting the number of airbags 35 installed on the detection bracket. The controller 13 is used to control the operating power of the vacuum pump 214 and the inflation pump 210 according to the detected number of airbags 35 installed.

[0049] Example 3

[0050] Compared to Embodiments 1 and 2, the difference in this embodiment is that when the controller 13 is electrically connected to the vacuum pump 214, the inflation pump 210, and the heating element 25, an AC contactor 14 is connected between them, and a surge suppressor 15 is also configured. Specifically, an AC contactor 14 and a corresponding surge suppressor 15 are connected between the controller 13 and the vacuum pump 214, between the controller 13 and the inflation pump 210, and between the controller 13 and the heating element 25. In this embodiment, both the AC contactor 14 and the surge suppressor 15 are mounted on the control panel 19.

[0051] The AC contactor 14 provides overcurrent fuse protection for the corresponding circuit, while the surge suppressor 15 protects the controller 13 from the impact of the air pump 210, air pump 214, and heater startup, thus better protecting the controller 13. In this embodiment, the AC contactor 14 in the circuit containing the air pump 214 and air pump 210 is a CJX6511 M5, and the AC contactor 14 in the circuit containing the heating element 25 is a CJX2510 M5. The corresponding surge suppressor 15 is SRC / 220V AC.

[0052] The above are merely embodiments of the present invention. The invention is not limited to the fields covered by these embodiments. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are able to access all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A thermal fatigue testing device for the airbag of a positive pressure oxygen respirator, characterized in that: Includes a controller, a hot air supply device, and a thermal fatigue testing bench; The hot air source supply device includes an electric heating water tank, a first temperature sensor, an air pump, a vacuum pump, and an electric valve; the electric heating water tank is equipped with a heating module; the first temperature sensor is located inside the electric heating water tank. The air inlet of the air pump is connected to the indoor air, the air outlet of the air pump is connected to the air inlet pipe of the electric heating water tank, the air outlet pipe of the electric heating water tank is connected to the air inlet of the vacuum pump, and the air outlet of the vacuum pump is connected to the air inlet of the electric valve. The thermal fatigue testing bench includes a second temperature sensor, a differential pressure sensor, a pressure relief valve, a detection air path, an airbag, and an alarm. The air inlet of the detection air path is connected to the air outlet of the electric valve. The detection connection port of the detection air path is threadedly connected to the airbag sleeve nut fixedly connected to the airbag. The detection end of the second temperature sensor is threadedly connected to the upper part of the detection air path, and the detection port of the differential pressure sensor is connected to the airbag pressure sampling port. The air outlet of the detection air path is connected to the pressure relief valve. The controller is electrically connected to the heating module, the first temperature sensor, the air pump, the vacuum pump, the electric valve, the second temperature sensor, the differential pressure sensor, and the alarm.

2. The thermal fatigue testing device for the airbag of a positive pressure oxygen respirator according to claim 1, characterized in that: The heating module includes multiple heating tubes, each of which is controlled by a controller.

3. The thermal fatigue testing device for the airbag of a positive pressure oxygen respirator according to claim 1, characterized in that: The electric heating water tank is also equipped with an inlet valve and a water level sensor that are electrically connected to the controller; the inlet valve is located at the water inlet end of the outer wall of the electric heating water tank; and the water level sensor is located on the inner wall of the electric heating water tank.

4. The thermal fatigue testing device for the airbag of a positive pressure oxygen respirator according to claim 3, characterized in that: The alarm includes a buzzer and a warning light.

5. The thermal fatigue testing device for the airbag of a positive pressure oxygen respirator according to claim 1, characterized in that: An air-water separator is installed between the air inlet of the air pump and the air outlet of the electric heating water tank.

6. The thermal fatigue testing device for the airbag of a positive pressure oxygen respirator according to claim 2, characterized in that: The electric heating water tank includes a tank shell and a tank liner; the bottom of the tank liner is provided with a mounting slot for placing the heating tube, and a partition is also provided on the mounting slot; omnidirectional casters are provided at the four corners of the bottom of the tank shell.

7. The thermal fatigue testing device for the airbag of a positive pressure oxygen respirator according to claim 1, characterized in that: The thermal fatigue testing bench also includes a testing platform. The testing gas path is installed on the testing platform via a fixed support base. The testing gas path is provided with multiple testing connection ports for installing and connecting airbags. The testing gas path is wrapped with thermal insulation cotton.

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