SU1479603A1 - Bit for rotary-percussive drilling - Google Patents

Abstract

The invention relates to drilling. The goal is to increase drilling efficiency and bit life. The bit includes a body 1 and peripheral 2 and internal 3 hard-alloy inserts with a hemispherical rock-breaking surface placed on its working end. Peripheral 2 and inner 3 inserts are inclined towards the body end in the direction from the center of the bit outward at an angle Α = aRstG [R / (R + 1.9R)], degrees, and at the same time in the direction of rotation of the bit at an angle β = ARCTG [R / (R + 3,5R)], hail, where R is the distance from the axis of the bit to the top of the insert, mm

R-radius of the sphere of the rock-destroying surface of the insert, mm. This embodiment of the bit ensures the direction of the resultant reaction forces of the bottom, acting on each insert during the drilling process, along the axis of the latter. 3 il.

Description

one

The invention relates to the drilling of wells, namely to bits for percussion rotary drilling.

The purpose of the invention is to increase the drilling efficiency and bit life.

Fig, 1 shows the chisel from the working end, a general view; figure 2 - section aa in figure 1; on fig.Z - section bb in figure 1.

The bit includes a housing 1 and peripheral 2nd internal 3 hard-alloy inserts with a hemispherical rock-breaking surface placed on its working end.

Internal inserts tilted to the side of the case in the direction from the center

bits outward at an angle determined from the expression

oL arctg

R

hail,

r-M, 9R

and simultaneously in the direction of rotation of the bit at an angle determined from the expression

/ 5 arctg --З7Гк grad where R is the distance from the axis of the bit to

insert tops, mm; g is the radius of the sphere of the rock-destroying surface of the insert, mm. Chisel works as follows. During the drilling process, impact drums and rotation are transmitted to the bit.

4 1

CO 05

with

and with its carbide inserts, it penetrates the rock, destroying it. On the side of the well, inserts are affected by reaction forces. Due to the inclination of the inserts to the working face of the bit body at angles Ь and Ь, determined from the above expressions, the resultant bottom reaction forces for each insert coincide with its axis, with the result that it only works in compression, which increases the drilling efficiency and durability of the bit.

Claims (1)

Invention Formula A chisel for impact-rotational drilling, comprising a housing and peripheral and internal carbide inserts with a polyspherical rock-cutting surface at an angle to it, from which the peripheral inserts are inclined in the direction from the center Q j 0 bits outwards, in order to increase drilling efficiency and bit life, the inclination to the working end of the body in the direction from the center of the bit outwards has internal inserts in addition to the peripheral inserts, and the internal inserts are simultaneously inclined to the working end of the case in the direction of rotation bit, while the angle of inclination of the inserts from the center to the outside is determined from the expression  arct & yyyyy and in the direction of rotation, from the expression p- arctg 5 R where R is the distance from the axis of the bit to insert tops, mm d - radius of the sphere of the rock-breaking surface of the insert, mm. ate Phil Aa tpufft