RU1789645C - Drill bit - Google Patents

Abstract

Usage: drilling wells shock-rotational method. SUMMARY OF THE INVENTION: The crown comprises a housing with a working head. The working head is reinforced with cylindrical rock-cutting inserts. The inserts are installed in groups of three inserts. In the group, the inserts are equally oriented along the axes: the centers of the inserts in the plan are located from each other at a distance C selected in accordance with expression 1, where d is the diameter of the insert. 3 ill.

Description

The present invention relates to mining, namely to a pneumatic percussion drilling tool, and may find application in the mining industry and geological exploration equipment,

A drill bit is known, in which the end part is reinforced with carbide inserts located at the vertices of the parallelogram, the center of symmetry of which coincides with the axis of the crown. The disadvantage of this design of the crown is the limited scope, since it is used only in punch drilling.

As a prototype, a drill bit was selected, in which the pin inserts are located on the end surface of the head in circular rows, the centers of which coincide with the axis of the crown.

The disadvantage of this design is the low drilling efficiency due to the increased energy consumption of rock destruction with this arrangement of inserts on the bottom of the crown. This is explained by the fact that each individual pin insert, acting on the rock, forms a limited area around itself

destruction, which does not interact with the destruction zones of adjacent pins located at a considerable distance from each other. Therefore, for effective drilling with such a crown, it is necessary to load it with high impact energy, which leads to breakage of the inserts. An object of the invention is to increase drilling efficiency.

This goal is achieved by the fact that in the design of the drill bit containing the housing with a working head reinforced in the end part by cylindrical rock-cutting inserts, the inserts are installed in groups of three inserts, and the inserts in the group are equally oriented along the axes, and in plan the centers of the inserts are located from each other at a distance C selected in accordance with the expression

1,,

where d is the diameter of the insert.

The distance C is selected for a certain d, proceeding from the following. The lower limit () of inequality is determined by the structural-technological gap between adjacent inserts, allowing their sharpening. The upper limit (1,) neraCO

WITH

Xi

from Yu

ABOUT

 ate

- based on the guaranteed overlap of the zones of rock destruction that occurs with the simultaneous introduction of each individual insert.

Figure 1 shows a general view of the crown, the end part of which is equipped with grouped inserts; figure 2 - group placement of inserts on the peripheral. part of the head; in Fig.3 is a plan view of the end part of the working head.

The drill bit consists of a housing 1, a working head 2, the end part 3 of which is reinforced with rock-cutting cylindrical inserts 4 of diameter d placed by separate groups 5, 6 and 7. Group 5 consists of four inserts, three of which are installed at the vertices of an equilateral triangle with a side equal to the distance C, and the fourth insert is spaced from the top of the triangle also at the distance C and serves to destroy the core in the central part of the face, Group 6 consists of three inserts located on the end part of the crown and mouth copulating at the vertices of an equilateral triangle at a distance S. Group 7 consists also of three inserts, but placed on the peripheral portion of the head 2. Moreover, two inserts

0

5

0

5

this group are installed in one circular peripheral row and together with other peripheral inserts of the remaining groups of type 7 provide the required borehole diameter. The inserts forming one or another group are equally oriented along the axis, i.e. parallel to each other and equally spaced from each other by a distance C, which is determined from the ratio:

1,.

In addition, purge channels 8 and slurry slots 9 are made on the crown head.

During operation, when the crown is loaded with shock pulses, all groups and inserts in the groups are simultaneously introduced into the rock. At the same time, each of the inserts in the group creates a fracture zone around itself, which interacts with the fracture zones of neighboring inserts, as a result of which the stresses in the rock are added, which leads to efficient drilling by reducing the energy consumption of rock fracture. Essentially, each individual insert in the group facilitates the incorporation of an adjacent one due to the mutual influence of the stress fields in the destructible zone.

Claims (1)

SUMMARY OF THE INVENTION A drill bit comprising a housing with a working head reinforced in the end portion by cylindrical rock cutting inserts, characterized in that, in order to increase drilling efficiency, the inserts are installed in groups FIG. / three inserts, and the inserts in the group of the same are oriented along the axes, and in plan the centers of the inserts are located from each other at a distance C, chosen in accordance with the expression 1 ,, where d is the diameter of the insert.