Anti-spread compound drill bit

Abstract

The invention discloses a reverse-expansion combined drill bit. The reverse-expansion combined drill bit comprises a first connecting rod, a mounting block, a mounting groove and a pressure relief hole, wherein diversion trenches are formed among guide strips, the mounting block is arranged on the vertical face, away from the first connecting rod, of a second connecting rod, the side, away from the second connecting rod, of the mounting block is provided with second drilling tools, and the sides, away from the mounting block, of the second drilling tools are fixedly provided with fourth drilling tools. The cross sections of the fourth drilling tools of the reverse-expansion combined drill bit are of isosceles trapezoid structures, the fourth drilling tools contact rock around the drill bit, so that the width of a borehole is ensured; cutting edges of the fourth drilling tools directly contact the rock, so that forward rotation and reversed rotation both can play a role in drilling; since the fourth drilling tools contact the rock, the cutting edges of the fourth drilling tools wear easily; since the number of the fourth drilling tools is larger than the original number of the bits,the wear degree of the subsequent fourth drilling tools in direct contact is reduced, so that the wear degree of the fourth drilling tools is reduced, thereby reducing the wear degree of the whole drill bit.

Description

technical field [0001] The invention relates to the technical field of raise drilling rigs, in particular to an anti-expansion compound drill bit. Background technique [0002] The technical principle of the raise drilling rig is that the motor of the drilling rig drives the hydraulic motor, the hydraulic motor drives the faucet, and uses the hydraulic power to transmit the torque to the drilling tool system, which drives the drill pipe and the drill bit to rotate, and the hob on the pilot hole drill bit or the reamer bit Under the action of drill pressure, pure rolling or micro-slip will be done along the rock working face at the bottom of the well. At the same time, the axial tension and pressure generated by the oil cylinder of the main engine will also act on the pilot hole bit or reaming bit through the power head and drill pipe, so that The hob of the pilot hole drill rolls under the action of drilling pressure, generating impact loads, which cause the hob teeth to imp...

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide a kind of anti-expansion compound drill bit, in order to solve the relatively serious problem of wearing and tearing when using in the current market that the above-mentioned background technology proposes

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