Down-the-hole hammer reverse circulation pipe-following drill bit suitable for large-diameter drilling

Abstract

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.

Description

technical field [0001] The invention relates to a down-the-hole hammer reverse circulation following pipe drill bit, in particular to a down-the-hole hammer reverse circulation pipe following drill bit suitable for large-diameter drilling. Background technique [0002] At present, in geotechnical drilling and excavation engineering, complex strata such as broken, loose, leaking, and pebbles are often encountered. Under such conditions, construction of engineering pile holes, especially large-diameter pile holes, is difficult to drill and has a long construction period. , Low hole forming efficiency, frequent accidents in the hole. The down-the-hole hammer follow-up drilling technology is a drilling method that combines bottom expansion drilling with air down-the-hole hammer and synchronously follows the casing. For drilling with a slightly larger pipe diameter, the down-the-hole hammer hammers the casing shoe at the same time to make the casing follow up synchronously, so a...

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