Coal discharging type coal mine excavation boring machine with drill bit convenient to replace

The invention discloses a coal discharging type coal mine excavation boring machine with a drill bit convenient to replace. The boring machine comprises a boring machine body, a connecting rod and anelectric push rod. The connecting rod is arranged on one side of the boring machine body, and the surface of the connecting rod is sleeved with a connecting plate. The connecting rod is connected intoa through hole, and the through hole is reserved in a limit plate. A connecting groove is reserved in the surface of the limit plate, and the outer edges of the limit plate are connected with connecting rails. The limit plate is arranged inside a drill bit body, and the drill bit body is arranged at one end of the connecting rod. The surface of the other side of the connecting plate is connectedwith the electric push rod, and limit rods penetrate through the interior of the connecting plate. First gears are arranged on the surfaces of the limit rods correspondingly in a sleeving mode, and the surfaces of the first gea