RU2670306C1 - Asymmetric cutter for a drilling tool - Google Patents

Abstract

FIELD: mining.SUBSTANCE: invention relates to the mining industry, in particular to a tool for a drilling tool. Cutter for the drilling tool comprises a tail portion, a working portion rotated at an angle to a longitudinal vertical plane of symmetry of the tail portion including the main, rear, side surfaces and the cutting portion. Working part is turned at an angle of 16÷28˚ around the longitudinal axis of symmetry of the tail section and is inclined to the left at an angle of 18÷31˚ with respect to the vertical symmetry plane of the tail part towards the center of the rotation circle. Radial notch is made at the junction of the working and tail parts on the inner side of the tool. On the outside of the working part, an additional face is made, and the cutting part is formed by the main and rear surfaces.EFFECT: technical result consists in reducing the cutting forces of the ground, reactive torque, material consumption, energy consumption and prolongation of service life.7 cl, 9 dwg

Description

The present invention relates to the field of the mining industry, in particular to the structures of removable cutting elements of drilling equipment and for rotary drilling of wells for various purposes in non-rocky soils and can be used in industrial and civil construction.

From the prior art known cutter screw augers, in particular RBM-35 (http://sdm-zavod.ru/products/tools/rezh-instrument/rbm-35). The device is characterized by the implementation of the body, containing an elongated tail part of the wedge-shaped form and the working part, whose planes of symmetry are in the same plane. The working part contains the main cutting edge, oriented at an angle to the horizontal plane with a cutting plate mounted on it. The cutter is used for drilling non-rocky soils for engineering wells. The disadvantage of this device is that when installing the extreme (forming the diameter of the hole) cutters in a position in which their cutting parts stand with optimal angles for cutting the soil. The tool holders and (or) the tail parts of the body of these cutters protrude beyond the nominal diameter of the well and rub against the wall of the well, changing its diameter in a large direction, creating additional resistance during drilling, both rotation and translational movement of the tool, as a result, they wear out prematurely.

If the extreme cutter is placed on the drill head so that its tool holder or body does not protrude beyond the nominal diameter of the well, then the cutting part of this cutter does not take a position close to optimal for effective cutting of the soil. In this case, the cutter is inclined by 19 degrees to the axis of rotation of the bur-head, which does not create optimal conditions for cutting. In addition to this, the side surfaces of the incisors, in the absence of 100% overlap, will abut the bottom of the well, creating excessive resistance to axial force when drilling.

To reduce the cutting forces of the soil during drilling, it is advisable to use a cutter, the design of which allows cutting of the soil in a position

close to optimal. One way to achieve this result is to use a cutter, the vertical planes of symmetry of the working and tail parts of which are at some angle to each other, and also rotated relative to each other.

In connection with the above, another analogue of the technical solution is the device according to US patent No. 5,143,163 “Digging tooth (drill bit)” (applicants Reedrill Inc., Kennametal Inc. [US], j. No. US 07751914 from 1991-08-29 , published 1992-09-01, IPC E21B 10/44; E21B 10/56). According to the description, the technical solution is a replaceable drill bit (cutter) for auger boring tool and includes an elongated working part and a shank, depending on the specified working part, with the possibility of connection with the auger support unit. The working part includes elongated main and rear surfaces and the first and second side surfaces. These surfaces are completed with a front surface containing cylindrical inserts. The working part is oriented at a certain angle to the longitudinal axis of the shank. The specified technical solution does not provide: optimal conditions for cutting the soil for the following reasons. The working part is not rotated around the axis of symmetry of the tail section, therefore, the cutter cannot be installed on the tool body so that the cutting edge of the tool (meaning the line through the tops of hard-alloyed, soldered cones) is on a straight line running from the axis of rotation of the drilling tool in the normal plane (perpendicular) to the axis of rotation of the drilling tool, or was in a position close to this, so that the side surface of the extreme tool (forming the diameter of the hole) does not crash into the side borehole wall, except in a situation where the drill axis of rotation will lie in the symmetry plane of the cutter. But such a situation cannot be considered close enough to the optimum. This cutter on the outside of the working part has no additional face, made at an angle of less than 90 ° to the front surface, and instead of the specified face there is a convex radius surface. In addition, the cutter on the specified patent does not provide a high strength of the device, when exposed to it. the process of cutting the soil bending loads, since the tail section with a cross section in the form of a rhombus, ceteris paribus (cross-sectional area, the magnitude of the acting forces)

resists bending better than a shank with a rectangular cross section with an aspect ratio of about 1 to 2 when it is bent on the long side.

The technical problem to be solved by the proposed group of inventions is to reduce the cutting forces of the soil during drilling, to reduce the reactive torque on the drilling tool, to reduce the material consumption of the product, to reduce, as a result, the energy expended on drilling, and to extend the service life of the drilling machine, which technical solution is used.

The technical problem is solved as follows. Cutter for drilling tools, contains the tail part, with the possibility of installation in the tool holder, the working part, rotated at an angle to the longitudinal vertical plane of symmetry of the tail part, including the main, rear, side surfaces and the cutting part. The working part of the tool is turned at an angle, degrees: 16 ÷ 28 around the longitudinal axis of symmetry of the tail and tilted to the left at an angle, degrees: 18 ÷ 31 relative to the vertical plane of symmetry of the tail towards the center of the circle of rotation. In the place of pairing of the working and tail parts, on the inside of the cutter, a radius cutout is made, on the outside of the working part, an additional face is made, which is 65 углом80 ° at an angle to the main surface, and the main cutting edge is formed by the main and rear surfaces.

Common with analogue signs are the presence of the tail and working parts, the inclination of the working part relative to the longitudinal vertical plane of symmetry of the tail part and the presence of the main, rear and side surfaces.

In general, the technical solution differs from the analogue in that the working part of the cutter ,. oriented at an angle to the longitudinal vertical plane of symmetry of the tail section, rotated around the axis of symmetry of the tail section, counterclockwise, arrows to the left towards the center of the circle of rotation, at an angle of 16 ÷ 28 °, including the main, rear, side surfaces and the cutting part, characterized by that the working part is oriented at an angle of 18 ÷ 31 ° to the longitudinal vertical plane of symmetry of the tail part, in the place of conjugation of the working and tail parts on the inner side of the cutter, a radius groove is made; eyes part is formed further face, at an angle to the principal surface 65 ÷ 80 °, the intersection of the major surface faces and further to the outer sides form minor cutting

the edge, and the main cutting edge is formed by the intersection (at the intersection of the main and rear surfaces) of the main and rear surfaces. In the particular case of execution, the cutting part is provided with at least one carbide cutting element.

In another particular case of execution, an asymmetrical cutter for a drilling tool differs from its implementation in general in that the tail section is made in the form of a tetrahedral truncated pyramid with an angle between two opposite faces, deg .: 3 ÷ 12 and angles between adjacent faces, deg. : 75 ÷ 105.

Preferably, the cutter in another particular case of execution differs from its implementation in the general case in that at least one blind groove is made in the tail section.

In the particular case of execution, the angle of tapering is, degrees: 30 ÷ 75.

In the particular case of execution, the additional face is located at an angle equal to the angle of rotation of the working part relative to the longitudinal vertical plane of symmetry of the tail part.

The cutter for the drilling tool consists of two main parts: tail and working. The tail part is designed for mounting in the receiving hole (pocket) of the tool holder and provides a stable position of the tool in the production of drilling operations. The working part is directly involved in the drilling of the soil. The optimal position of the working part is such a position in which the resulting vector of cutting forces will be minimal and the cutter's resource maximum, ceteris paribus. Turning the working part of the cutter relative to the tail part allows you to place the tail part of the outermost, forming the diameter of the well, the cutter with the pocket inside an imaginary cylinder of the well, so that they do not rub against the borehole wall, creating additional resistance to rotation and spoiling the borehole wall. At the same time, the execution of an additional face on the outer side surface of the working part of the cutter reduces the resistance during cutting due to the fact that the working part does not protrude beyond the boundary of the drilled well, and only the auxiliary cutting edge rotates along the boundary of the drilled well. From the inside of the cutter, i.e. with the one that is located closer to the center axis of the well when installing the tool into the tool holder, a radius cut is made in place

the transition from the tail of the cutter to working. The shape of the excavation depends on the technology of its implementation. It is advisable to perform a notch, in the form of a surface area formed by a surface of the second order, having at least a pair of centers of circles. Radius notch serves both to reduce the resistance when drilling, and to relieve stress concentration at the interface of the tail and working parts of the tool. The inclination angle of the working part is from 18 to 31 degrees, provides the optimal location of the tail section at the optimum position of the working part for cutting the soil, as the angle of 18 ° is minimal for not outputting the tail part beyond the boundary of the imaginary cylinder of the well, and at an angle of more than 31 ° a pairing will occur cases of tool holders of two adjacent incisors.

The main surface of the working part of the cutter is the one on which the drilled soil comes off while drilling. The back surface of the working part is the face facing the cutting surface (the bottom of the well). The side surfaces contain a radius notch and an additional face, respectively. The main and rear surfaces form the cutting part, mainly in two ways: by intersection and transition, i.e. in the first case, the cutting part is the cutting edge, in the second - the front surface, in which, as described in the particular case and examples of execution, carbide teeth or other cutting elements can be installed. Auxiliary cutting edges are formed by the intersection of the main surface with the side surfaces.

In the framework of the present invention, the cutter can be used without an additional carbide element, provided that the material from which it is made conforms to the requirements for hardness for drilling operations on the relevant soil. However, in the particular case, the cutting part of the cutter is provided with carbide elements to improve its performance. In this case, the requirements for the material from which the cutter is to be made can be reduced. The carbide element can be made in the form of a plate, and in the form of several spike-shaped teeth, as described in more detail in the embodiments of the invention. The carbide element can be positioned directly on. cutting part, and partially, on the main surface. The requirements for the hardness of the specified element are based on the hardness

drilled soil. The carbide element can be soldered to the working part of the cutter, obtained by applying a carbide layer by flame spraying, or by pressing into pre-drilled holes on the cutting part of carbide teeth.

Another particular case of execution involves the execution of the tail part of the cutter in the form of a truncated four-sided pyramid. This form of execution of the tail part allows the tool to be fixed in the receiving hole of the tool holder, creating a support for the tool when drilling and preventing the tool from turning around the axis of symmetry of the shank. The limiting values of the angles are chosen in order to ensure reliable and convenient installation of the cutter in the receiving hole of the tool holder, as well as its removal from the receiving hole of the tool holder.

The taper angle, i.e. the angle between the main and rear surfaces, (or the continuations of these surfaces, when the surfaces go into the cutting part), together with the front angle (the angle between the front surface and the main plane, in which the axis of rotation of the drill head and the cutting edge of the tool lie ), the back angle (the angle between the back surface and the back plane which is perpendicular to the axis of rotation of the drill head and passes through the cutting edge of the tool) is selected so that they provide the optimum ratio of cutting forces to strength and res Su cutter during drilling of frozen clay, loam, sand, sandy loam. When the taper angle changes to the lower side, the front and rear corners change accordingly, which reduces the cutting forces (reactive torque and axial force on the face), but leads to a decrease in the strength and life of the tool. By increasing the taper angle, the opposite result is obtained.

In the particular case of execution, the additional face is at an angle from 10 to 25 degrees to the plane perpendicular to the main plane of the working part of the tool. That is. the arrangement makes it possible to eliminate unnecessary contact of the outer side surface of the working part with the ground during rotary drilling, especially if the cutter is installed in close proximity to the peripheral (cylindrical) surface of the well.

The tool bit (the breeding part) for rotary drilling has several tool holders distributed throughout the base, each of which contains an open mounting hole

for receiving the tail of the cutter. During the operation of a drilling tool, all the cutters are subject to high loads, and the cutters located closer to the periphery of the drilled well, especially high loads, do more work than all the others, since the trajectory of their movement is greater, which leads to their strongest wear. Due to these increased loads, the receiving shank of the outer, outer cutter and the tool holder are also subject to relatively high loads.

As a result, in the course of drilling operations, it is necessary to regularly replace the wear tools of drilling equipment.

The invention is illustrated by the following schematic drawings:

FIG. 1 - asymmetric cutter for a boring tool with a dihedral cutting plate, main view;

FIG. 2 is an asymmetric cutter for a drilling tool with a dihedral cutting plate, top view;

FIG. 3 is an asymmetric cutter for a boring tool with a dihedral cutting plate, front view;

FIG. 4 is an asymmetric cutter for a drilling tool with a flat cutting plate, top view;

FIG. 5 is an asymmetric cutter for a drilling tool with a flat cutting plate, front view;

FIG. 6 - asymmetric cutter for drilling tools with carbide studs, top view;

FIG. 7 - asymmetric cutter for boring tools with carbide studs, front view;

FIG. 8 is an asymmetrical cutter for a drilling tool with a cylindrical tail;

FIG. 9 is an asymmetric cutter for a boring tool with a tool holder mounted on a drill head, general view;

The figures indicate the following positions:

1 - cutter for drilling tools;

2 - tail section;

3 - working part;

4 - the main surface;

5 - back surface;

6 - radius notch;

7 - additional side;

8 - cutting element;

9 - tail groove;

Below are examples of specific embodiments of the invention.

Asymmetric cutter 1 for a boring tool (Fig. 1-3) includes a housing consisting of a tail 2 and working 3 parts. The working part contains the main 4 and rear 5 surfaces, as well as two side surfaces. On the inner side surface is made of a radius notch 6 to reduce the resistance during drilling of the soil. An additional edge 7 is made on the outer side surface. Intersecting, the main and rear surfaces form the cutting part. A rock-cutting cutting element 8 is placed on the main surface and the cutting part. It may have a flat upper surface bounded by the front and side cutting edges (FIGS. 4, 5), and may contain two intersecting edges forming the upper surface (FIGS. 1-3) . Thus, depending on the mechanical properties of the soil for which the cutter is intended, its cutting elements 8 may have a different shape, to a greater or lesser extent, increasing the efficiency of the destruction of the soil in the face. So, unlike the ones described above, the cutting elements can have the form of spikes (Fig. 6, 7), facilitating the destruction of thawed soils with a small content (up to 30% by volume) of small boulders. On the tail part of the cutter, a groove 9 is made for fixing the locking element of the tool holder lobe.

To increase the impact strength of the cutter, the straight edges can be rounded with a radius.

The tail part of the cutter is made in the form of a tetrahedral truncated pyramid with an angle between the opposite faces of 3 °. The tail part of the cutter in cross section has the shape of a rhombus, with angles of 90 °. Angles can be 75 and 105 ° respectively. The turn of the working part of the cutter around the longitudinal axis of symmetry of the tail part is made at an angle of 21 °, and the inclination of the working part relative to the vertical plane of symmetry of the tail part towards the center of the circle of rotation at an angle of 24 ° (Fig. 1). Presented in FIG. 8 the performance of the cutter is characterized by the execution of the tail,

mostly cylindrical. This form of execution, respectively, requires a similar shape of the receiving opening of the tool holder to install the cutter. Fixing the cutter in the receiving hole is done with a pin.

An example of placement of the incisors installed in the tool holders on the drill head is shown in FIG. 9.

The proposed device can be manufactured using known technologies for processing materials and engineering used in the manufacture of drilling equipment. The proposed device can be used mainly in the drilling of engineering wells in non-rocky soils, including for drilling frozen soils.

Proposed. Embodiments of the invention illustrate preferred embodiments of the technical solution. The scope of legal protection cannot be limited to specific examples of execution, but is determined by the claims.

Claims (7)

1. A cutter for a drilling tool containing a tail part, with the possibility of installation in a tool holder, a working part rotated at an angle to the longitudinal vertical plane of symmetry of the tail part, including the main, rear, side surfaces and the cutting part, characterized in that the working part is rotated angle 16 ÷ 28 ˚ around the longitudinal axis of symmetry of the tail and tilted to the left at an angle of 18 ÷ 31 ˚ relative to the vertical plane of symmetry of the tail in the direction of the center of the circle of rotation, at the junction point eyes, and the tail portions with the inner side of the cutter is formed radiusnaja recess on the outer side of the working part is formed further face, and the cutting portion is formed by the main and back surfaces. 2. A cutter for a drilling tool under item 1, characterized in that the additional face is angled to the main surface 65 ÷ 80. 3. A cutter for a drilling tool under item 1, characterized in that the cutting part is additionally provided with at least one carbide cutting element. 4. A cutter for a drilling tool under item 1, characterized in that the tail section is made in the form of a tetrahedral truncated pyramid with an angle between two opposite faces of 3 ÷ 12˚ and angles between adjacent edges of 70 ÷ 110˚. 5. A cutter for a drilling tool according to Claim. 1, characterized in that at least one blind groove is made in the tail section. 6. A cutter for a drilling tool according to claim 4, characterized in that the taper angle is 30 ÷ 75. 7. Cutter for a drilling tool under item 1, characterized in that the additional face is located at an angle equal to the angle of rotation of the working part relative to the longitudinal vertical plane of symmetry of the tail part.

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