SU1652503A1 - Percussive drill bit - Google Patents

Abstract

The invention relates to the mining industry and makes it possible to increase the efficiency and reliability of the operation of the bit for percussion rotary drilling. The bit includes a housing 1 with a working end (PT) 3, made as part of a sphere and equipped with carbide inserts (TV) 4. The latter have a flight over PT 3, increasing from the periphery to the center, and their tops lie on a spherical surface. the radius of which is less than the radius of the sphere () RTZ, which in turn is 0.8-1.2 diameters (Au) of the bit. During the drilling process, due to the increase in the outflow of TB4 over PT 3 from the periphery to the center of the bit and the optimal ratio between R Cf and Od, equal strength and improved loading conditions for TB 4 and simultaneously create additional free space above the bottom hole. This leads to the destruction of the rock by a larger cleavage and more efficient removal of the products of destruction from the bottom. 2 Il. S S C S C K SL O CO

Description

The invention relates to the mining industry and can be used in bit structures for percussion rotary drilling.

The purpose of the invention is to increase the efficiency and reliability of the bit.

Figure 1 shows the chisel, a general view; figure 2 is the same, the view from the working end.

The chisel contains a copra 1 with a shank 2 and a working end 3 as part of a sphere with a radius. Carbide inserts 4 are placed on the working end, whose outreach increases from the periphery to the center of the bit, and the tops lie on a spherical surface 5 having a radius Hop smaller than the radius of the sphere of the working end r0p Rf. At the same time, the radius of the sphere of the working end 3 of the housing 1 is 0.8-1.2 bit diameter / Od /. Purge channels 6 are made in the bit body.

Chisel works as follows.

Before the start of drilling, the chisel is connected to an air hammer that has an increased impact energy, any of the known fasteners that are most mobile in the loaded state: spline, bayonet, ball, etc. During the drilling process, the torque and shock loads from the hammer are transmitted to the chisel. Under the action of shock and rotation, carbide inserts 4 destroy the rock. Cleaning the well from the products of destruction

is carried out by the spent energy carrier (compressed air) supplied to the slaughter through the channels 6 of the bit body 1. A smooth increase in the departure of inserts 4 above the worker

the end 3 of the housing 1 in the direction from the periphery to the center of the bit ensures equal strength of the inserts 4, creates additional free space above the bottom surface, which improves

rock cleavage conditions, cleaning of the bottom, and reducing the percentage of secondary crushing degradation products. The proposed relationship between the radius of the sphere of the working end 3 of the housing 1 and the diameter of the bit

provides the most favorable conditions for loading carbide inserts 4, especially at the periphery of the bit, in the drilling process.

All this increases the efficiency and reliability of the bit.

Claims (1)

Invention Chisel for percussion rotary drilling, comprising a housing with a working end as part of a sphere and placed on The body butt end carbide inserts, characterized in that, in order to increase the efficiency and reliability of the bit, the carbide inserts overhang the working face of the body increases from the periphery to the center of the bit, and their tops lie on a spherical surface whose radius is smaller than the radius of the sphere of the working end of the body, while the radius of the sphere of the working end of the body is 0.8-1.2 of the bit diameter.