Patent ID: 9670728
Date: 2017-06-06
CPC Classifications: E21B

Claim:
1. A rotary impact drill, comprising a vibration excitation mechanism ( 1 ) consisting of a hydraulic motor, an excitation box, an eccentric shaft, a gear and an eccentric block, wherein a rotating mechanism ( 3 ) is mounted at the bottom of the vibration excitation mechanism ( 1 ) by a guide rod ( 19 ) with a spring ( 4 ); a flushing mechanism ( 10 ) is mounted at the bottom of the rotating mechanism ( 3 ); wherein the rotating mechanism ( 3 ) consists of a rotary box ( 8 ), and a driving gear ( 7 ), a rotary gear ( 6 ) and a rotary connecting sleeve ( 9 ) which are mounted in the rotary box; the rotary gear ( 6 ) is tightly cased on the rotary connecting sleeve ( 9 ) and is engaged with the driving gear ( 7 ); a connecting rod ( 2 ) connected directly to the bottom of the excitation box ( 16 ) is arranged in the rotary connecting sleeve ( 9 ), and the rotary connecting sleeve ( 9 ) is connected with a double-layer drilling rod mechanism ( 11 ) after passing through the flushing mechanism ( 10 ); the double-layer drilling rod mechanism ( 11 ) comprises an outer rotary drilling pipe ( 28 ) and an inner impact drilling string ( 25 ), wherein the inner impact drilling string ( 25 ) is located in the outer rotary drilling pipe ( 28 ) by a guide bearing bush ( 26 ); a first latch ( 24 ) for connecting the connecting rod ( 2 ) is arranged at the top of the inner impact drilling string ( 25 ); a drilling bit connecting sleeve ( 29 ) is connected with the bottom of the double-layer drilling rod mechanism ( 11 ), and an impact head ( 12 ) connected with the inner impact drilling string ( 25 ) is arranged in the drilling bit connecting sleeve ( 29 ); and a drilling bit ( 13 ) below the impact head ( 12 ) is connected with the drilling bit connecting sleeve ( 29 ) by a front connector ( 30 ); wherein the double-layer drilling rod mechanism ( 11 ) consists of the outer rotary drilling pipe ( 28 ) and the inner impact drilling string ( 25 ); the outer rotary drilling pipe ( 28 ) thereof is in threaded connection with the drilling bit connecting sleeve ( 29 ); a plurality of the double-layer drilling rod mechanisms are provided correspondingly; the outer rotary drilling pipes ( 28 ) are in threaded connection with each other, and the inner impact drilling strings ( 25 ) are connected with each other by second latches; the guide bearing bush ( 26 ), a lock bar lug ( 27 ) and a return spring ( 23 ) are arranged between the inner impact drilling string ( 25 ) and the outer rotary drilling pipe ( 28 ); the lock bar lug ( 27 ) is tightly cased on the inner impact drilling string ( 25 ), and the return spring ( 23 ) is arranged between the lock bar lug ( 27 ) and the guide bearing bush ( 26 ).