High-pressure water jet drilling and reaming device for coal mine seam through drilling

The utility model discloses a high-pressure water jet drilling and reaming device for coal mine seam through drilling. The high-pressure water jet drilling and reaming device comprises a drilling rig, a high-pressure water jet system, a drill rod and a drill bit; the drill rig drives the drill rod to rotate and drill in a coal mine seam; the high-pressure water jet system comprises a water tank, a high-pressure water pump and a high-pressure rubber hose; the high-pressure rubber hose is connected and communicated with the tail of the drill rod by use of a rotating joint; a nozzle for jetting out high-pressure water is arranged on the drill bit; the drill bit is capable of rotating around the axis thereof under the driving of the rotation of the drill rod; the nozzle comprises a propelling nozzle arranged on the front end of the drill bit and a lateral nozzle arranged on the sidewall of the drill bit; the lateral nozzle comprises a cinder discharge nozzle which is arranged backwards by inclining to the axis of the drill bit; the propelling nozzle is capable of applying at least axial impact force on a coal body ahead so that the stressed coal body is gradually broken after being soaked in high-pressure water or ground by the drill bit; the backward cinder discharge nozzle is added and capable of pushing broken coal cinder to move toward one side of the inlet of a drilled hole, and therefore, the discharge of the coal cinder is accelerated, the coal cinder is prevented from accumulation to hinder cinder discharge and the depth of hole forming is increased.