SU1617146A1 - Bit for drilling large-diameter holes - Google Patents

Abstract

The invention relates to a drilling technique and can be used for the drilling of large diameter bore holes. The purpose of the invention is to increase the durability of the bit by increasing the reliability of fixing the paws when using elastic gaskets. The chisel includes a housing 1 with slots 2 with an inclined surface, placed in the sockets 2 paws 3 with an inclined occipital surface 6, locking bolts 11 with thread and placed on the legs of the roller cutter 4. The gaskets 9 are placed between the occipital surface 6 of the paws 3 and the inclined surface of the housing 1, and in the side surfaces of the legs are drilled with conical undercuts. The threaded holes for the fixing bolts 11 are made with conical protrusions for engagement with the surfaces of the conical undercuts of the legs. The occipital surface 6 of each paw 3 and the inclined surfaces of the nests of the housing 1 are made with projections directed toward each other. When the locking bolts 11 are screwed in, they fall into the conical undercuts of the leg 3 with their projections and move it, compressing the gasket 9, as a result of which a reliable tensioning of the leg 3 in the slot of the body 1 is ensured. f-ly, 6 ill.

Description

Fik.1

The invention relates to a drilling technology and can be used for rolling conic drilling of large diameter wells in various mining and geological

CONDITIONS :

The purpose of the invention is to increase the long eternity of the bit by increasing the reliability of fixing the paws when using elastic gaskets.

FIG. 1 shows a chisel, a general view; in fig. 2 is a section A-A in FIG. 1; in fig. 3 shows a section BB in FIG. 1, with bolts fastened; in fig. 4 the same, with loose bolts; in fig. 5 and 6 - mount paw with sawtooth protrusions,

The chisel includes body 1, on which, in the sockets 2, removable legs 3 with cones 4 are placed. The legs are mounted with projections 5 with an emphasis on body 1 and have oblique occipital surfaces 6. Each nest 2 in cross section is made in the form of a closed contour (Fig. 2) the sides are on the outside 7 and on the inside 8 parallel to the side surfaces of the legs.

Between the beveled surface of the paw 6 and the counter inclined surface of the nest is placed a gasket 9, made of rubber. In the sides of the socket in the threaded holes 10, bolts 11 with threads, having tapered peaks 12, and a cylindrical part 13 devoid of threads are fixed on the same axis. The paws are made with blind holes 14 with conical broadening 16. The occipital surface of the paw and the slope 1; and the rear side of the nest surface is provided with saw-tooth projections 16 directed towards each other.

The operation of the bit at the bottom is no different from the work of the known bits. G} gush wear cones for armament and support are replaced with paws 3. For this, bolts 11 are turned out so that they emerge from their holes 14 with their conical projections and take paws out of nests 2. When installed. New paws on the body 1 are initially inserted into each nest of the curvature 9, s then the paw is inserted so that it rests its occipital surface on the gasket. The thickness h of the gasket and its modulus of elasticity E are selected so that they satisfy the following relation d Poc-h where d is the diameter of the broadened part of the drilling

in the paw;

Grew - passport ngl ruzka on

bit;

h is the thickness of the elastic strip;

E - mo, the mass of elasticity of the gasket material;

F is the contact area of the gasket; n is the number of paws on the chisel.

At this, it is achieved that the conical undercuts 15 overlap the holes 10 only a little more than half (Fig. 4). Then the locking bolts 11 are twisted, which with their conical tops 12 0 fall into the conical broadening 15. Under the action of the screwing bolts, the paw is displaced in the slot parallel to the longitudinal axis of the bit and compresses the gasket 9. Screwing continues until the paw 5. -protrusion 5 is installed on the casing 1. At the same time, the bolts, with their cylinders 13, fall into the mating surfaces of blind holes 14 and reliably keep the paw from falling out, being at the same time in its unstable state, since the gasket due to axial elasticity stvl a pressure on the occipital part of the legs, and n, in turn - at the bolted connection. During the operation of the bit at the bottom of the axial load, the load that comes from one paw, being smaller in magnitude as a component of the elastic force of the gasket, does not unravel the lgp in hd-back 2. In the case of sawtooth protrusions, the paw is even more reliably retained 0 is given in the socket.

The advantage of the proposed bit in comparison with the known devices is that the mounting of the paw in a closed nest with a tight fit 5 ensures its secure hold. In this case, an accurate installation of the foot on the ledge is achieved, which allows the cutting cones to be brought one level. This is essential for the normal operation of the 40 cones. In addition, assembly — disassembly of the feet — is simplified and accelerated in the bit. moreover, the legs of serial case bits can be used without changing their design.

Claims (2)

Claim 1. Chisel for drilling of large-diameter wells, including a housing with slots with inclined surfaces, cones, 5 holes. Removable paws of the mounts with nakloinyi-plats with nagging surfaces and nesting i-ia side surfaces of the paws of the mowers fixed in the nests of the nest, characterized in that, in order to increase the durability of the bit 10 by increasing the reliability of fixing the paws, it CKab.x eHoynpyrMj-v i; - | lay-ups, each of which is placed between the back of the paw and the inclined surface of the body, with blind holes with conical widenings in the side surfaces of the paws, and fixing bolts with conical ends for interacting with the surfaces of the paws broadening and placing locking bolts in the blind holes. 2. Chisel according to claim 1, characterized in that the occipital surface of each paw and the inclined surfaces of the housing sockets are made with sawtooth projections directed towards each other, bs Thebes Figg (Pw. "