The invention discloses a down-the-hole hammer reverse circulation
pipe-following
drill bit suitable for large-
diameter drilling. The down-the-hole hammer reverse circulation
pipe-following
drill bitcomprises an upper
drill bit body and a lower
drill bit body, wherein the lower
drill bit body is hung on the lower part of the upper
drill bit body, central channels are formed in the middle part ofthe upper drill bit body and the middle part of the lower drill bit body, a groove is formed in the lower part of the upper drill bit body, a raised shaft is arranged at the top end of the lower drillbit body, the shape of the groove corresponds to the shape of the raised shaft, the raised shaft is inserted in the groove, the hole
diameter of the groove is larger than the outer
diameter of the raised shaft, the raised shaft can slide in the groove, and when the raised shaft slides and abuts against one end of the groove, the bottom of the lower drill bit body moves out of the outer edge of adrilling tool to realize reaming drilling. The down-the-hole hammer reverse circulation
pipe-following drill bit has the beneficial effects that downhole double
slag suction channels are arranged andmatched with
involute type slagging guide grooves in the bottom surface of the drill bit, the reverse circulation efficiency is high,
impact energy efficiency of a down-the-hole hammer is high, the slagging effect is good, meanwhile, ball teeth on the edge of the bottom surface of the drill bit are densely arranged, and the service life of the drill bit is effectively prolonged in combination withgood slagging conditions.