SU907214A1 - Drilling bit - Google Patents

Description

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The invention relates to a rock-destroying tool, and, exactly, to drill bits for rocks composed of soft and weakly cemented rocks.

The known drill bit contains a body and a diamond-containing matrix with channels for the passage of the washing agent and partitions directing the flows of the washing agent to the side of rotation of the drill bit p.

However, when this bit is operated at a high rotational speed, the cutting elements of the die, located in front of the washing channels, are not washed enough with the washing liquid, which leads to a rapid exit of the cutting elements.

The closest in technical essence and the achieved result is a drill bit containing K (jpnyc and a working head with rock-breaking elements in the form of hollow cylinders with cutting ends, the cavities of which are communicated with the cavity of the housing 2.

The disadvantage of this bit is the low efficiency of drilling operation with direct flushing due to significant pressure losses in the flushing system.

The purpose of the invention is to increase the efficiency of the bit by improving the flushing system.

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This is achieved by the fact that the rock-breaking elements are set obliquely in the direction of rotation, while the cutting ends of the elements are not perpendicular to their longitudinal axis. At the same time, the working head is made with pressure cavities connected to the body cavity and rock-breaking elements.

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In addition, a filter is placed in the cavity of the housing and the working head.

FIG. 1 shows a chisel, general view, cut; in fig. 2 - the same.

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view from the working end; in fig. 3 - section AA on phi1. one.

The chisel contains a hollow steel body 1 and a working head 2 with blades 3, equipped with rock-breaking elements in the form of hollow thin-walled cylinders 4 with cutting ends 5.

The working head 2 in the zone of each blade 3 is made with a pressure cavity 6 connected to the cavity of the housing 1, and rock cutting elements, the cutting ends 5 of which protrude above the surface of the blades 3, are made perpendicular to the longitudinal axis of the cylinders 4 and inclined in the direction of rotation of the bit.

For removal of the spent washing liquid with sludge on the working head 2, grooves 7 are made, extending from the outlet openings of the cylinders 4 to the slots 8 on the side surfaces of the working head.

In the process of drilling, the protruding edges 5 of the cylinders 4, being introduced into the bottom rock, perform the functions of destructive elements and are continuously cleaned of the particles of broken rock formed by them with a jet of washing liquid entering under high pressure through the cylinder 4 to the bottom. The slurry is carried by the flushing fluid through the discharge channels 7 and the grooves 8 from the bottomhole zone into the annulus. To eliminate the blockage of the cavities of the cylinders 4, a filter 9 s is inserted into the central channel of the housing I and the working head 2: a plurality of small holes 10, which serve to delay inclusions larger than the cavity section of the rock-forming elements, which can fall into the washing liquid.

The use of thin-walled cylinders at the same time as rock-breaking elements and to achieve the jetting effect provides high-quality cleaning of the cuttings from the sludge and a constant high mechanical speed of drilling due to the constant contact surface of the cutting ends 5 of the bottom hole during the entire Time of work until full wear. Hollow cylinders 4 can be made of diamond cakes and lined with a metal sheath.

Claims (3)

Invention Formula one . A drill bit containing a body and a working head with rock-breaking elements in the form of hollow cylinders with cutting ends, the cavities of which communicate with the body cavity, characterized in that, in order to increase the efficiency of the bit by improving the flushing system, the rock-breaking elements are set obliquely in the direction of rotation, with In this case, the ends of the elements are perpendicular to their longitudinal axis. 2. A bit of OP. 1, differing from the fact that the working head is made with pressure head cavities connected to the cavity of the body and rock cutting elements. 3.Doloto on PP. 1 and 2, about t l and that the filter is placed in the cavity of the body in the working head. Sources of information taken into account in the examination 1. USSR author's certificate No. 237071, cl. Е 21 В 9/36, published. 1962. 2. US patent number 3280926, cl. 175-330, published. 1966 (prototype).