Mining combined expanding bit

Abstract

The invention belongs to the technical field of drill bit and particularly relates to a mining combined expanding bit. The mining combined expanding bit structurally comprises a spindle, a primary drill bit, a secondary drill bit and a tertiary drill bit. The spindle comprises a front spindle and a back spindle, wherein the front spindle and the back spindle are coaxially arranged and are in threaded connection. The conical portion of the primary drill bit is in threaded connection with the left end of the front spindle. The secondary drill bit is in threaded connection with the side, close tothe right end of the front spindle. The tertiary drill bit is in threaded connection with the left end of the back spindle. The spindle is internally provided with water through holes, the water through holes penetrate through the whole spindle and the primary drill bit. The water through holes include a primary water through hole, a secondary water through hole a tertiary water through hole gradually increased in diameter from left to right, and circulation of waterflow in the water through holes is facilitated. The water through holes are provided with plugging-prevention plugs for wiping inner walls of the water through holes. The mining combined expanding bit can be quickly changed, the high temperature caused by friction force in the drilling process is effectively reduced, the service life of the drill bit is prolonged, and the drilling efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of drill bits, in particular to a mine-used combined reaming drill bit. Background technique [0002] The reaming drill bit is a drilling tool for reaming the processing hole during machining. During construction, it is usually necessary to drill processing holes of different diameters, and at the same time supply dust removal water during the drilling process to reduce the high temperature of the drill bit due to friction. phenomenon of damage. For the convenience of carrying out graded reaming construction and changing drill bits, various reaming drill bits have appeared on the market. Chinese patent CN201610263121.4 discloses a reaming drill bit, including a first cutting edge, a second cutting edge, a third cutting edge, a fourth cutting edge, a Morse taper shank, cooling holes on the outer surface, and cutting grooves , Central cooling hole; the central cooling hole and the outer side cooling hole of ...

AI Technical Summary

Problems solved by technology

Chinese patent CN201620676240.8 discloses a replaceable combination drill bit for coal mines, including a guide level, a first-level reaming bit, a second-level reaming bit and a drill handle, a detachable set of a first-level reaming bit, and a second-level reaming bit On the drill shank and rotate with the drill shank, the guide stage is connected to the drill shank by threads and is used to fix the secondary reaming drill and the primary reaming drill at the same time, which solves the problem that the traditional drill cannot be replaced and the drilling efficiency Low, slow slag discharge, low strength, low utilization rate, etc.

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