RU2682824C1 - Drill bit for percussion-rotary drilling - Google Patents

Abstract

FIELD: soil or rock drilling; mining.

SUBSTANCE: invention relates to the field of creating drilling rock cutting tools for percussion-rotary drilling wells. Drill bit for percussion-rotary drilling consists of a shank and a hemispherical head with rock-breaking elements placed on its working surface. At the end of the shank there is tore puck with an eccentric protrusion on the bottom installed with the possibility of angular rotation in a vertical plane. Movable hemispherical part of the head is equipped with a hinge element, providing the possibility of rotation of the movable part of the head relative to the shank in the plane of placement of the eccentric protrusion in the opposite direction from it. Movable hemispherical part of the head on the opposite side of the eccentric protrusion of the tore washer is equipped with an elastic element.

EFFECT: technical result consists in increasing the efficiency of rock destruction at the bottom of a well during percussion-rotary drilling when implementing an eccentric impact pulse and creating spalling forces acting in the bottom plane.

1 cl, 2 dwg

Description

The invention relates to the field of creating drilling rock cutting tools for rotational percussion drilling.

Known drill bit of the pin type, consisting of a shank and a head with a rock-cutting indenter and a purge hole located on its working surface [RU No. 169571 of 08/08/2016, publ. 03/23/2017].

The disadvantage of this crown is the low drilling efficiency when applying the central drill bit while drilling.

The closest technical solution is a cone bit for impact-rotary drilling, comprising a housing, a trunnion, on which a cone is mounted for rotation, a hammer interacting with a cone [a.s. USSR No. 829846, MKI E21B 9/08, dated 05/18/79, publ. 05/15/81].

The disadvantage of this technical solution is the low efficiency of the destruction of rocks when a central impact is applied.

The present invention is aimed at improving the efficiency of rock destruction at the bottom of the well during rotational impact drilling by transmitting eccentric shock pulses to the bottom, creating tangential rock shearing forces and acting in the face plane.

The indicated technical result is achieved by turning the hemispherical head pivotally fixed due to the implementation of eccentric shock pulses by means of a torus washer made on the lower end of the shank with the protrusion eccentrically located on its lower end. In this case, the rotation of the hemispherical head will occur in the plane of applying an eccentric impact, namely, in the plane of the protrusion on the torus washer in the opposite direction from it, for this there is an angular clearance in the direction of rotation of the hemispherical head. The torus washer with a protrusion eccentrically located on its lower end is rotatably mounted, which excludes the transmission of a bending moment to the shank of the bit caused by eccentric application of a shock pulse. To return to the initial position of the hemispherical head, it is spring loaded from the side opposite to the eccentric protrusion on the washer.

The totality of the features of the claimed invention, namely the presence of a pivotally located part of the bit head, as well as a torus washer located on the end of the shank with a protrusion eccentrically located on its lower end, at a relative position that allows rotation in the plane of applying an eccentric impact, was not found in the known technical solutions, which assumes compliance of the claimed drill bit with the novelty criterion.

Compliance with the inventive step is confirmed by the fact that with an eccentric application of impact, an increase in the volume of rock destruction at the bottom due to the concentration of high stresses under certain rock cutting inserts, as well as the implementation of tangential impact forces in the face plane, leading to additional rock cleavage and increase the size of the fracture holes, is observed. and also providing separation from the bottom of the part of the rock mass that has experienced a destructive effect, is divided by cracks, but still held in the holes of destruction by the forces of its internal connections.

As a result, the efficiency of rock destruction at the bottom increases, which consists in a higher rate of penetration of wells in medium hardness and soft brittle non-elastic rocks.

The invention is illustrated by drawings, where:

in FIG. 1 shows the inventive pin type drill bit;

in FIG. 2 shows the mechanism of rock destruction by the proposed bit, where: shank - 1; connecting slots - 2; torus washer - 3; eccentric hemispherical protrusion - 4; locking washer - 5; movable part of the bit head - 6; fixed part of the bit head - 7; hinge element - 8; elastic element - 9; rock cutting elements -10; cylindrical washer - 11; bolts - 12, drummer - 13.

The head of the bit consists of a movable 6 and a fixed 7 parts connected by a hinge element 8. Maintaining the movable part of the head of the bit in the initial position is carried out using an elastic element 9.

To destroy rocks at the bottom, the movable part of the bit head contains rock-breaking elements 10. For assembling the movable and stationary parts of the drill bit head, the design is equipped with a cylindrical washer 11 fixed to the bit head with bolts 12.

The proposed drill bit for rotary hammer drilling works as follows. The torus washer 3 receives the central impact impulse from the hammer 13 by the upper end, transmitting an eccentric shock impulse to the shank by means of the protrusion 4 on the lower end of the torus washer 3, while the possibility of turning the torus washer 3 removes the bending moment from the shank 1.

Bending moment M = ΔР⋅Е, where ΔР - impact force, N; E - the eccentricity of the protrusion 4 on the end of the torus washer 3. The use of a movable torus washer eliminates the bending moment M, which does not exclude the transfer of an eccentric shock impulse to the armament.

An eccentric shock pulse communicated to the shank 1 is transmitted to the bit head, causing the movable hemispherical part of the bit head 6 to rotate in the plane of the eccentric strike by a certain angle β (Fig. 2). The rotation of the movable hemispherical part of the head of the bit 6 provides the appearance of tangential impact forces, leading to a change in the shape of the fracture holes, an increase in their size and separation from the bottom of the rock mass, which experiences a destructive effect, is divided by cracks, but is still held in the fracture holes by the forces of its internal connections.

The value of the tangential displacement of the rock-cutting elements 10 is set by the angle β. For example, for very hard rocks, the angle β can be small or equal to zero, and as the hardness decreases and the ductility of the rock decreases, increase to the maximum possible value. The tangential displacement of the rock cutting elements will be determined by the dimensions of the moving hemispherical head 6 and the dimensions of the rock cutting elements 10.

To return the moving hemispherical part of the head 6 to its original position after the end of the fracture cycle, the bit is equipped with an elastic element 9.

The use of the proposed drill bit for rotational percussion drilling will increase the efficiency of destruction of medium and soft brittle non-ductile rocks at the bottom of the well when sinking exploration and other wells for various purposes using downhole percussion mechanisms.

Claims (1)

Drill bit for impact-rotary drilling, consisting of a shank and a hemispherical head with rock cutting elements located on its working surface, characterized in that a torus washer with an eccentric protrusion at the lower end is mounted on the end part of the shank with the possibility of angular rotation in the vertical plane, and the hemispherical part of the head is equipped with a hinge element that allows the movable part of the head to rotate relative to the shank in the plane of the eccentric ary protrusion from it in the opposite direction, the movable hemispherical head portion on the opposite side of the eccentric protrusion torus washers equipped with an elastic member.

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