The utility model provides a self-closing locking device of a single
air door for a
coal mine, which relates to the technical field of a
coal mine ventilation
system and comprises a door plate, a mechanical locking device and a balancing weight, the door plate is arranged on roadway walls, the mechanical locking device is hung at a position between the roadway walls on two sides, a guide wheel is rotatably arranged above the front side of each roadway wall, and the balancing weight is arranged on the front side of the roadway wall. A first steel
wire rope is connected to the upper portion of the front side of the door plate, and a movable
pulley is rotationally installed at the top of the balancing weight through a support. According to the utility model, the
pulley blocks are additionally arranged at the two door plates, the first steel
wire rope is wound around the first
pulley block and is connected with the balancing weight, and the other end of the balancing weight is wound around the second pulley block through the second steel
wire rope and is connected to the mechanical locking device; therefore, the linkage locking function of the two single air
doors is achieved, and the problem that the two air
doors can be opened by 50% at the same time is solved.