The working principle of the mine pneumatic air door control device is based on the coordinated operation of pneumatic drive and automated sensing control. By detecting passage demands, transmitting control commands, and driving the door mechanism, it achieves automatic opening, holding, and closing of the air door, ensuring smooth underground passage and stable equipment operation. The specific process is as follows:

1. Sensing Trigger Phase
   The device uses sensors installed on both sides of the air door (such as infrared sensors, ultrasonic sensors, etc.) to monitor passage targets in real time. When personnel, vehicles, or equipment enter the detection range of the sensors, the sensors capture the movement signal and convert it into an electrical signal, which is transmitted to the core control unit (controller), issuing a passage demand command.

2. Command Judgment Phase
   After receiving the sensor signal, the controller performs logical judgment based on preset programs. It verifies the validity of the signal (excluding interference signals) and confirms the current status of the air door (e.g., no door on the same side is open, no equipment abnormalities, etc.) through feedback from the locking device.

3. If the conditions are met, the controller generates an open-door command; if not, it temporarily suspends action to avoid conflicts.

4. Pneumatic Drive Phase
   The controller transmits the open-door command to the pneumatic control components (such as solenoid directional valves, flow control valves, etc.). After receiving the command, the pneumatic components control the compressed air to enter the pneumatic actuator (usually a cylinder) through the air tube, pushing the piston rod inside the cylinder to extend. This, in turn, drives the air door panel to rotate around the hinge via transmission structures like linkages, smoothly opening to the preset angle. During this process, the flow control valve regulates the airflow speed to ensure the door opens slowly and steadily, avoiding impact.

5. Passage Holding Phase
   Once the door panel is fully opened, the pneumatic control components lock the cylinder position to keep the door open. At the same time, audio-visual warning devices (such as indicator lights and buzzers) activate, signaling "Door is open, safe to pass" to the passage target, allowing sufficient time for passage. If there is a continuous passage demand (e.g., a long vehicle passing through), the sensors continue to send signals to ensure the door remains open.

6. Reset and Closing Phase
   After the passage target has completely passed through the air door, the sensors detect no remaining targets within the detection range and send a "passage completed" signal to the controller. The controller initiates a preset delay program (the delay time can be adjusted as needed), and after the delay ends, it issues a close-door command. Upon receiving the command, the pneumatic control components exhaust the cylinder air, causing the piston rod to retract under the reset force (such as the cylinder return spring or gravity assistance). This drives the door panel to close slowly via the transmission structure.

7. Sealing and Reset Phase
   During the door closing process, the sealing strip on the edge of the door panel tightly fits with the door frame, achieving effective sealing. After fully closing, the locking device automatically engages to ensure the door remains stably closed. Meanwhile, the controller resets to standby mode, waiting for the next sensing trigger to complete the entire work cycle.

Through the above process, the mine pneumatic air door control device leverages the efficient drive of pneumatic power and the precise coordination of automated sensing control to achieve unmanned operation of the air door, meeting the demands of passage and equipment control in complex underground environments.