RU1778265C - Carbide tip for drilling crown bits - Google Patents

Abstract

Usage: production of rock about the destructive tool for rotary hammer drilling. SUMMARY OF THE INVENTION: the insert is made in the form of a cylinder with an axial channel. The working surface of the insert is made in the form of one and a half mating with the cylindrical lateral and internal surfaces of the insert.

Description

The invention relates to equipment for drilling holes in rocks by the rotational impact method, in particular to crowns.

An insert for rotary drills and rotary stabilizers is known, having a conical groove acting as an indicator of wear of the insert, however, this design does not have any positive effects during hammer drilling.

Closest to the proposed technical essence is the design of a carbide insert made with a channel. Such a design makes it possible to significantly save hard alloy due to the tubular shape and to improve the removal of drill fines from holes.

A disadvantage of the known construction is the presence of stress concentrators (acute angles) on the impact surface having a triangular shape.

Contact with the rock of such an insert will be made in a straight line,

which, with the current tendency to increase the power of perforators, will lead to high specific stresses and rapid destruction of the insert.

Another significant drawback of the known crown is the insufficiently effective use of the joint action of the inserts on the affected surface, i.e. shock waves from two existing inserts, emanating from their surface, will be scattered without interacting with each other.

The aim of the invention is to increase the service life of carbide inserts and increase the productivity of the drilling process.

This is achieved in that in a carbide insert having a cylindrical side surface, an axial channel and a working surface according to the invention, the working surface has the shape of one and a half mating with the cylindrical side and inner surface of the insert.

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The strength of the inserts is ensured by the fact that the impact working surface is toroidal. The absence of sharp angles ensures the absence of stress concentrators and, at the same time, increases the reliability of the insert. In addition, the same factor. (Toroidal range) makes it possible to create the effect of the addition of shock waves along the interposed axis and between them. As a result, the use of impact energy is improved.

Figure 1 shows the insert (frontal section and top view); in FIG. 2 - effect of the impact of the knock on the rock. (Dotted line indicates the spread of the impact); Fig. 3 shows the effect of the joint action of the inserts (the impact surface of the crown is shown, shock waves are indicated by dashed lines).

The insert contains a cylindrical body 1, an impact working surface 2, made in the form of one and a half mating with the cylindrical side and inner surface of the insert and an axial channel 3. The inserts of the proposed design are sealed or pressed into a crown, type KTS (GOST 17196-77).

During drilling of the holes, the insert with its working surface 2 interacts with the rock. The contact line of each insert will be a circle (i.e., 3.1 times the contact line of a known insert, respectively, the specific stress of the limit

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the desired insertion will be as many times smaller). Shock waves begin to emanate from the surface of the insert, which, when added to the waves from the other inserts, produce rock destruction. Thus, the effect of the insert extends not only to the contact zone, but also outside it (Figs. 2 and 3 are the points of intersection of the dashed lines). At the same time, flushing fluid is supplied through channel 3, which at the moment of separation of the insert from the rock cleans the contact area for the next shock.

When using the proposed insert due to the absence of stress concentrators, increasing the line of contact between the insert and the rock, the operational stability of the inserts is increased and additional (cumulative) fracture effects are created, allowing to increase the speed and reduce the energy consumption of drilling.

Claims (1)

The claims A carbide insert for drill bits containing a cylindrical side surface, an axial channel and a working surface, characterized in that, in order to increase the operational stability and / productivity of the drilling process, the working surface is made in the form of one and a half mating with the cylindrical side and inner surfaces insertion. "City / V / /   /// h / /  1 s h 9 i. / c. 3