Punching device

The utility model discloses a trepanning device which comprises a base, guide rods are arranged on the outer walls of the two sides of the top of the base respectively, the tops of the guide rods are connected with guide plates in a sliding mode, a fixing plate is arranged on the tops of the guide rods, a threaded rod is rotationally connected to the inner wall of the fixing plate, the threaded rod penetrates through the guide plates, and a rotating disc is arranged on the top of the threaded rod. A rack is arranged on one side of the guide plate, a drill rod is rotationally connected into the rack, a guide shaft is arranged at the top of the drill rod, a motor is arranged on the outer wall of the back face of the guide plate, a transmission assembly is arranged between the motor and the guide shaft, and a cooling mechanism is arranged at the top of the guide plate. A rotating shaft is arranged on the outer wall of one side of the rack, and the transmission wheel is arranged at the output ends of the rotating