RU1793079C - Cone drill bit - Google Patents

Abstract

Usage: in the mining industry for cone drill bits intended primarily for shock cone drilling. Essence: cones 3. 4, 5 along the middle crowns 11, 12 are made with a taper angle at the apex equal to twice the difference between the right angle and the angle of the axes of the axles 2 to the axis of the bit. The carbide teeth on the crowns 11, 12 are parallel to the chisel rails. When working with the teeth of the middle crowns 11 and 12, additional exposure planes are created. This contributes to a more effective destruction of the rock. The reaction from the bottom is directed along the teeth, which reduces the bending stresses in the teeth and increases the impact efficiency. 2 ill.

Description

The present invention relates to the mining industry and can be used in cone drill bits, primarily designed for shock cone drilling.

Known drill bit. comprising paws and trunnion mounted paws with the possibility of rotation of multi-cone cones having carbide armament on the tops, main and peripheral parts of cones.

The disadvantage of this bit is the low efficiency of its operation, since the design parameters of its armament: the diameter and number of teeth on the peaks, the main and peripheral parts of the cones, as well as the orientation of the teeth relative to the axis of the cone are set without regard to the possibility of drilling with imposition of percussion pulses. Therefore, a significant part of the impact force is uselessly absorbed by the bit itself, not realized in the destruction of the rock being drilled.

If the rational value of the tooth pitch is exceeded, the boundaries of the holes of destruction and cracks in the rock from the influence of any

crowns on the rock are removed from each other and

 the deepening of the well slows down until the number of holes and their sizes reach certain values. In cases where the pitch of the tooth is less than the rational value, the impact is reduced by the component load transferred by the teeth to the rock, which also reduces the drilling speed.

A significant drawback is that the teeth are oriented perpendicular to the crown surfaces of the cones, and the taper of the latter is different in different parts of the cones. Therefore, the directions of the clove axes at the moment of interaction with the rock and the axial load do not coincide. This leads, on the one hand, to a decrease in the efficiency of transfer of impact energy through the teeth and, accordingly, to a decrease in the destructive effect of the rock. On the other hand, the mismatch of the axial load action directions with the axis of the tooth transmitting it entails the appearance of additional bending stresses on the rock-cutting surface of the tooth, which are especially dangerous when presenting shock loads, iVro reduces the resistance of the tooth and, accordingly, bit construction as a whole.

The foregoing relates primarily to crowns located on the main parts of the cones, since a significant part of the bits worked in very strong and strong rocks were replaced due to chipping of the teeth of these crowns.

The closest technical solution is a cone drill bit,

containing paws with inclined trunnions and mounted on trunnions with the possibility of rotation of the cone with inner, middle and peripheral crowns and; carbide teeth placed on

On the cones of the cones, In it, the diameter and number of teeth on the inner, middle and peripheral crowns are optimized in terms of the distance from the axis of the bit and the frequency of the shock load on the bit in order to exclude the dependence of any cone on the annular section of the slab destroyed by one of these crowns with lagging behind the destruction of the remaining area of the face. However, the above disadvantages associated with

By the mismatch of the direction of the axial load (respectively, the application of shock pulses), they are stored in this bit. : l. /. ......., -.....: ./. :. ; ..

The purpose of the invention is the increase of pr. Oise5

bit water increase due to increase

Impact efficiency and bit durability by reducing bending stresses on the teeth. .......,;. , ...

This goal is achieved by the fact that in

With a drill bit containing cones with inclined trunnions and mounted on trunnions with the possibility of rotation of the cone with internal, middle and peripheral crowns and carbide teeth 5 "and, located on the cones, the cones along the middle crowns are made with a taper angle at the top. equal to the doubled difference between the right angle and the angle of inclination of the axle axles to the axis of the bit, and

0 carbide teeth on the middle rims are parallel to the axis of the bit.

In Fig.1 shows a cone drill bit: in Fig.2 - combined projections of cones.

5 . The cone drill bit contains a paw 1 with a pin 2, cones 3, 4, 5 mounted on the pins using rolling bearings b, 7 and a sliding bearing 8. The cones have a multi-conical shape,

0 on the outer surfaces of the cones-crown surfaces, rock-cutting crowns are made in the form of pressed-in

 carbide holes

with rock-cutting parts protruding above the crown surfaces. So, at the 1st cone, the inner crowns are 9.10, the middle crowns are 11. 12 and the peripheral crowns are ..13; 14; : -;

The axis of the tilt axle with respect to the axis of the bit at an angle a,

The conical surfaces of the 1st cone designed for crowns 11 are made with the same angle ip at their apex with an offset relative to each other, the lane surfaces of the middle crowns of the cones are also made with a relative angle to each other with the same / Ch. p at their peaks.

When combining the projections of the cones along the axis of inclination of the trunnion and the center of the lock case bearing of the cones), as shown in Fig. 2, a diagram of the aligned bottom of the well is formed. As can be seen from figure 2, the onus surfaces of the middle cones of the cones form a stepped shape, and due to the equality of the angles of the cone at the apex of all these surfaces, they form parallels to each other, the rare crowns in figure 2 are indicated by the numbers .15, 16, 17, 18 , nineteen.

The angle (p. At the apex of the cone of the middle cones of the cones is set so that the axis of the tooth at the moment of interaction with the rock coincides with the direction of the axial load, i.e., on the combined bottom face, the axis of the tooth is parallel to the axis of the bit, and the generatrix coincides with the plane including the axes base and tooth, perpendicular to the axis of the long a .. -.;.,.

The angle (p / 2 between this generatrix and the axis of the bit is 90 ° - p, respectively, the angle p is 2 (90 ° -a).

The bit works as follows. During the drilling process, the axial load and torque, as well as the shock load, the latter using pneumatic or hydraulic hammers, are transmitted to the bit. Under the influence of the indicated loads, the cones of the cones rotate along the face, causing the destruction of the rock. The destroyed rock is removed from the surface of the bottom and from the well by a gaseous or liquid cleaning agent supplied through the bit.

Due to the stepped contour of the middle crowns of the bit on the face, additional exposure planes are formed in its main part, which contributes to more efficient destruction of the rock and, consequently, to an increase in the mechanical drilling speed.

The formation of cones of step-shaped form on the conical surfaces of the middle crowns when combining their projections and the interconnection of their taper angle with the angle of inclination of the axis of the pins to the axis of the bit ensures that the axial load directions of the bit coincide with the axes of the teeth of the middle crowns. This increases the transmission efficiency of the shock load (energy) to the destruction of the rock and reduces the bending stresses in the teeth themselves.

Axial loading and shock pulses are transmitted by the teeth of the proposed bit to the bottom, with little or no energy loss. Exceeding or decreasing the value of the indicated angle entails the appearance on the face, at the point of contact of the tooth with the rock, of a lateral component of the load directed at a right angle to the axis of the tooth, causing bending stresses on its rock-cutting surface, but not participating in the destruction of the rock .

Using the proposed bit will allow to increase the mechanical drilling speed and penetration to the bit when shock-cone method of drilling wells.

SUMMARY OF THE INVENTION A cone drill bit comprising lamas with inclined pins and mounted on pins with the possibility of rotation of the cone with inner, middle and peripheral crowns and carbide teeth placed on the cones of the cones; that, in order to increase the performance of the bit by increasing the efficiency of the impact and durability of the bit by reducing the bending stresses on the teeth, the cones along the middle crowns are made with a taper angle at the apex equal to twice the difference between the right angle and the angle of inclination of the axes of the axles to the axis of the bit and carbide teeth on the middle crowns are parallel to the axis of the bit.