SU1051208A1 - Drill bit - Google Patents

Abstract

A DRILL CROWN, containing a crown ring with sludge channels and cutting inserts, including a support with a groove and a borehole; core-forming and central incisors, characterized in that, in order to improve its operational durability by increasing the reliability of attachment of the incisors, facing one another the faces of the well- and core-forming incisors have grooves that, together with the groove, form a seat under the central incisor.

Description

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The invention relates to a rock drilling tool for drilling wells with core sampling, namely drill bits.

The well-known crown consisting of a crown ring with sludge drainage by narrow channels, supports made in the form of hollow-rejfHX triangular struts, and incisors made in the form of plates of a prismatic shape of rectangular cross section.

Also known is a drill crown, containing a crown ring with sludge-extracting channels and cutting inserts, including a support with a groove and a borehole, core-forming and central incisors 2.

The disadvantage of these crowns is the low operational STAUSTOST of the crown, since when assembling before soldering it is difficult to obtain a fixed position of the incisors relative to the body (crown ring). In the process of drilling, the displacement of the incisors from a predetermined position leads to an intensive wear of the crown along the outer and inner diameters, as a result of which the penetration of the crown is reduced.

The purpose of the invention is to increase operational durability by increasing the reliability of fastening the cutters.

The goal is achieved by the fact that in a drill bit containing a crown ring with sludge channels and cutting inserts, including a support with a groove m and borehole, core-forming and central incisors, facing one another the faces of the borehole and core-forming cutters have grooves that, together with the base of the support forms a nest under the central incisor.

FIG. 1 shows the proposed drill crown, a general view; in fig. 2 - view from the side of the working end; in fig. 3 - working sector.

The drill crown includes a corona ring 1 with shedding channels

2 and cutting inserts containing supports

3 with grooves 4 and rock-crushing elements consisting of three cutters in the form of plates, well-forming 5, central b and core-forming 7. Side grooves 8 are made on the inner faces of plates 5 and 7, which together with the groove 4 of support 3 form a slot under the central plate 6. The central plate 6 has a 5 cutting edge 9 located below the cutting edges 10 of the plates 5 and 7 to a height h, defined by the formula: h.

where a is the angle of incisor, hail; tj is the width of the peripheral plate.

mm;

li - the width of the central plate, mm.

Burov crown works as follows.

When introduced into the rock between the peripheral {well- and core-forming) cutting edges 10, the pillars of the rock are formed, destroyed by chipping and cutting by the central cutting edge 9. For softer ductile rocks, the cutting elements are made with a cutting angle of 55 65 ° and the central cutting edge 9 is located lower than during drilling, rocks of medium hardness, when the cutting angle of rock-breaking elements is a-65-80 °. The width of the peripheral plastic at this m is equal to li 9-r-ll mm, the width of the central I, 3-4 mm.

OPENING the side grooves on the inner edges of the peripheral plates ensures that the central plate is fixed

0 before assembling the soldering tool. During installation, the support of the assembled rock cutting element in front of the brazing ensures its reliable fixation with respect to the crown ring, as a result of which the quality of crown manufacturing is improved, the crowns are protected on the wellbore and core-forming surfaces, and consequently, the durability is increased. Making the rock-crushing element composite and displacing the cutting edge of the central plate relative to the cutting edges of the peripheral plates makes it possible to eliminate the crown hanging on the resulting pillar of the rock in the inter-cut space and increase the drilling rate.

Claims (1)

DRILLING CORE containing a crown ring with sludge-removing channels and cutting inserts including a support with a groove and a borehole; core-forming and central incisors, characterized in that, in order to increase its operational stability by increasing the reliability of attachment of the incisors, the faces of the borehole and core-forming incisors facing one another have grooves that, together with the support groove, form a nest for the central incisor. (L