SU859592A1 - Drill bit - Google Patents

Description

(54) DRILLING CROWN

The invention relates to mining, namely drilling bits for rotary drilling. A well-known drill crown, containing the body and wear-resistant inserts, the rock-breaking edges of which are placed along the curve | 1. The disadvantage of this crown is that it does not ensure the even distribution of the torque power of the drilling mechanism at the bottom hole, since in the peripheral part of the bottom the crown should destroy a larger area of the bottom than in its central part. This leads to a loss of energy and a decrease in the rate of drilling. The purpose of the invention is to increase drilling efficiency by uniformly distributing torque energy over the bottom of the well. The goal is achieved by the fact that 4to rock-cutting edges are placed along a curved line described by the following equation., / Zc3Vp е..1..ets "for Go:, 3d", where 8, g are cylindrical coordinates with the Z axis directed along crown axis; Th is the distance from the axis of the crown to the beginning of the curved section, cm; Hz is the crown radius, see. Performing the middle line of the inserts in accordance with the indicated dependence will make it possible to evenly distribute the torque energy over the bottom hole area and, on this basis, to increase the drilling rate. FIG. I shows the drill crown, axial section; in fig. 2 - the end of the drill bit with inserts having an average line of the proposed curvature; in fig. 3 - the end of the drill bit in which the individual inserts of the curvilinear form are displaced in the azimuthal direction, but are located along the lines of the proposed curvature. Burov crown consists of a body b skirt 2 and carbide inserts 3, pressed into the body I of the crown. Each insert has a constant cross section of the cutout edge 4 and a curved middle line 5, which, within Gd 0.3g, is made in accordance with the dependence

. (t)

(denoted above). In the range from O to Go, the insert can be right or. generally absent, since in this case the zeitral part of the bottom of 0.3 gk is destroyed by chipping.

In order to prove the necessity of the chosen dependence (1), we use the dependence of the shape, the midline of the insert at the crown of rotational-impact drilling, which evenly distributes the energy of the axial force and the torque of the drilling mechanism over the bottom hole area (with the above signs).

ajji, llry- 0..P1 arcjin - VlTv) 1

Vl-afel

-iarajA E VE iir

 y a-u-

(r- (g / g (about o 0.3 0.38 0.45 0.52 0.60 q ° o o1.2 162639 g / g (o o 0.4 0.5 0.6 0.7 0.8,

There are several variants of the crown: with solid (Fig. 2) and separated inserts (Fig. 3). In each version of the crown there are 6 openings for the flushing channels.

The drilling is carried out as follows.

By turning the drilling mechanism, the cutting edge 4 of the insert 3 is inserted into the rock, destroying it by cutting and chipping.

Let us estimate approximately the increase in the drilling rate of the proposed crown Vj in comparison with the speed of drilling by the well-known crownU | In the case of the known crown, the lengths of the inserts from O to 0.5 gk and from 0.5 gk to Gk are in a ratio of about 3: 5 (and, from O to about 0.2 gk, there is no insert at all). In the proposed crown, the lengths of the inserts for the same limits (ranging from 0.2 g to O. ZGK insert straight) are in the ratio 2: 6. Consequently, the ratio of energies at the bottom of the well will be (0.25 X 2 - (- 0.75 X 6): (0.25 X 3 + 0.75 X 5) -1.113. Thus, 11, the torque energy y known crown is not spent on destruction.We assume that the speed of drilling is approximately proportional

AT a4l,, ir "/

/ C-GoGl.

where

,-and.

M is the torque of the drilling mechanism;

9 - angle of rotation of the crown after each stroke;

Q - axial force of the drilling mechanism. To go from the rotational impact drilling mode to the rotational drilling mode, cp 0 should be set. In this case (2), as a result of the limiting transition at a 0, transforms into the (1) dependence.

The specific implementation of the proposed drill bit is given in the table in the form of coordinates (in units of g) of the middle line 5, made in accordance with dependence (I), with Go 0.3rf (lines 1 and 2) and with Go 0.4 g (line 2 and 3).

square root of energy, then the increase in the drilling rate of the proposed crown will be 5.6%.

To blast 1 million tonnes of ore, it is required to drill 5,000 40,000 p / m of wells at a cost of I p / m from 0.97 to 5 rubles. The economic effect will be (0.97-5.00) X 0.056Х40000 (2.18-11.2) thousand rubles / 1 mlkg.

Claims (1)

Invention Formula A drill bit containing a body and wear-resistant inserts, the rock-breaking edges of which are placed along a curved line, characterized in that, in order to increase drilling efficiency due to the even distribution of the energy of a MOMeirra taper along the bottom of a well, rock-breaking edges are placed along the curve described by the following equality e-VfeRi-9 Go 0.3r ", at 0.68 0.75 0.90 1.00 526392110 0.9 1.00 where c, d are the cylindrical coordinates with the Z axis directed along the axis of the crown; Th is the distance from the axis of the crown to the beginning of the curved section, cm; Hz - radnus crowns, see 859592 № type 6 Sources of information taken into account during the examination I. USSR author's certificate 626199, cl. E 21 C 13/02, 1976 (proto).