Bolt positioning mechanism based on gear and rack transmission

The bolt positioning mechanism comprises a base and a side frame which are vertically connected with each other, a first seat body is arranged on the surface of the base, a rotating shaft is rotatably inserted into the upper portion of the first seat body, one end of the rotating shaft is outwards connected with a rotating gear, and the other end of the rotating shaft is inwards connected with a rotating arm; the upper part of the side frame is rotationally connected with the tail part of a driving cylinder; an output shaft of the driving cylinder is downwards and rotationally connected with a rotating arm; a second seat body is vertically arranged on the outer side of the surface of the base, a displacement block is arranged on the side portion of the second seat body in an up-down sliding mode, a rack is arranged on the inner side face of the displacement block, the rotating gear is in meshing transmission with the rack, and a vertically-downward positioning plug pin is arranged at the bottom of the displac