RU2307932C1 - Rock-cutting tool - Google Patents

Abstract

FIELD: mining, particularly rock-cutting tools for underground mineral mining and rock cutting by mining and tunneling machines, plowing apparatus and other mining and construction machines provided with cutting tools.

SUBSTANCE: rock-cutting tool comprises holder and cutting head to be connected to the holder. Holder is wedge-like in cutting head area. The wedge has cylindrical top defined by generator transversal to side faces of cutting head and rock-cutting tool axis. Cutting head is shaped as hollow trihedral prism having one ridge used as cutting edge. Orifice communicated with edge-like cavity is created between another two ribs. Remote rib of the cavity is shaped as cylindrical surface with generator transversal to side faces. Wedge-like taper is 5-10° greater that of wedge-like holder. Wedge-like resilient members are arranged between cutting head and holder.

EFFECT: improved capabilities of cutting tool.

5 dwg

Description

The invention relates to mining machines, more specifically, to a cutting tool of mining machines (hereinafter “cutting tool”), and may find application in underground mining, in mining and roadheaders, plowing machines, in other mining and construction machines equipped with a cutting tool.

Known mining tools made in the form of a holder and fixed to it a removable cutting part in the form of an insert reinforced with plates, caps or cores of hard alloy. For example, a plow cutting tool, given in / 1 /.

The insert has a tail that is rigidly fixed in the holder.

The disadvantage of this design of the cutting tool is the lack of micro-compliance when meeting with inclusions. This leads to a decrease in the impact strength of the reinforcement of the cutting tool due to the fact that the impulse of the impact load has a relatively short period of time; and in the presence of frequent inclusions in the face, to relatively frequent breakdowns of the cutting tool.

Another disadvantage of such a cutting tool is the absence of microdisplacements (micro-flexibility) of the main cutting edge in response to the direction and coordinate of the application of the vector of the resultant downhole reaction.

Another disadvantage is the constant growth of the contact area of the rear edge of the cut with the face of the face with an increase in the friction path.

An increase in the blunting pad changes the distribution of the face reaction forces along the back face, changes the coordinates of the application of the resultant force from the bottom side, but these changes are not taken into account due to the rigidity of the insert mounting in the holder. Front angle, cutting angle, rear angle - remain unchanged. This leads to an increase in the projection of the blunting area along the rear face onto the face plane, and, consequently, to an increase in the pressing forces (feed forces) and cutting forces, and as a result, to an increase in the specific energy consumption of cutting and a decrease in productivity.

Also known is a cutting tool / 2 /, consisting of a holder and a movable cutting head, which is mounted in the elastic support of the holder.

In such a cutting tool, the elastic displacement of the cutting part along the axis of the cutting tool is ensured, which at peak and impact loads increases the impact resistance of the cutting tool. This technical solution was made by us as a prototype. But the prototype solution also has several disadvantages:

a) the cutter is not compliant in the direction perpendicular to the axis of the cutter. At a cutting angle of 90 °, such a cutting tool is not compliant with the forces acting on the front face. At other cutting angles, the ductility is negligible and mainly due to the action of the feed forces, which insignificantly affect the impact strength of the cutting tool. Thus, the prototype is characterized by the intransigence of the front face (front surface) of the cutting tool under shock loads, when the cutter meets inclusions. The lack of compliance leads to relatively frequent breakdowns of the cutting tool;

b) for a cutting tool according to the prototype, the cutting angles do not change with an increase in the blunting area along the rear edge of the cutter.

With the growth of the blunt pad in this cutting tool, friction losses increase; for a free feed system (with plowing), the pressing forces increase, which leads to a decrease in the cutting depth, that is, to a decrease in productivity; to increase the cutting and feeding forces, to increase the specific energy consumption, that is, to reduce the performance of the cutting tool.

The aim of the invention is to improve the performance of the cutting tool, which consists in increasing the resistance of the front · face to shock loads, reducing the average cutting force, increasing the productivity of the mining machine, reducing the specific energy consumption of the cutting process.

The goal is achieved in that the cutting tool, including the holder and the detachable cutting head, is made so that the holder in the part of the interface with the cutting head has the form of a wedge with a vertex in the form of a cylindrical surface with a radius R, which is perpendicular to the side faces of the cutting head and the axis of the cutting tool. The cutting head is made in the form of a hollow trihedral prism, in which one of the ribs is a cutting edge, and a hole is made between the other two ribs in the wedge-shaped cavity, and the remote edge of this cavity has the shape of a cylindrical surface with a radius R, the formation of which is perpendicular to the side faces and the axis of the cutting tool. In this case, the narrowing angle of the wedge-shaped cavity of the cutting head is 5-10 ° greater than the sharpening angle of the wedge-shaped part of the holder, and the cutting head and holder are mated along cylindrical surfaces with a radius R.

The cutting head is mounted on the holder by connecting the wedge-shaped elastic elements with the surfaces of the holder and the cutting head, or it can be performed by one of the known methods, for example, by a pin pressed into the holder hole and extending into the grooves on both side edges of the cutter. The fastening of the cutting head on the holder with a pin can be combined with an integral connection of the elastic elements with the holder and the cutting head in the cavities between them.

The invention is illustrated by drawings, where

in FIG. 1 schematically depicts the inventive mining tool (side view);

in FIG. 2 is a front view of FIG. one;

in FIG. 3 - option of fixing the cutting head on the holder;

in FIG. 4 - change of angles on the cutting head.

The mining tool (see FIGS. 1, 2) contains a cutting head 1, which is fixed on the wedge-shaped section 2 of the holder 3. The top 4 of the wedge-shaped section 2 has the shape of a cylindrical surface with a radius R, which is perpendicular to the side faces 5 of the wedge-shaped section 2, which has a rectangular section. This generatrix is perpendicular to the axis of the cutting tool, it is also perpendicular to the side faces of the cutter if they do not have lateral sharpening angles, and parallel to the main cutting edge if the cutter has a rectangular hard-alloy flat reinforcement.

In the cavity between the cutting head 1 and the wedge-shaped portion 2 of the holder 3, an elastic element 6 is placed, for example, of polyurethane.

The elastic element 6 has a wedge-shaped shape and can be located either just under the front wall of the prism, that is, under the front face, or under the front and rear walls of the prism, that is, under the front and rear faces of the cutting part, or under the rear wall of the prism.

It is possible to perform the inventive cutting tool with a removable elastic element, when replacing the cutting head, the elastic element can be replaced at the same time. In this embodiment, the cutting head is fixed to the holder with a pin 7.

The cutting head 1 is fixed on the holder 2 by welding (vulcanization), or by gluing both surfaces to the elastic element 6, or by a known method: pin 7, tightened in the hole of the holder so that the pin extends into the grooves on both side faces of the cutting head.

The inventive mining tool works as follows. After installing and securing it in the fist of the executive body of the combine or in the spacer of the plow, he is ready to work.

When the executive body moves to the bottom, the vector of the resulting downhole reaction changes depending on the ratio of the components of the feed force (Y) and cutting (Z), the cutting angle of the cutting head will automatically be oriented counter to this vector, within malleability, turning it on the holder. As a result, friction costs will be minimized, cutting force will be minimized.

When meeting with hard turning on the front face, the cutting head 1 will automatically rotate along the surface with a radius R, compressing the elastic element 6, thereby increasing the duration of the force pulse and increasing the resistance of the hard alloy, generally increasing the resistance of the cutting tool to impact loads.

When the cutting tool is blunted, the face reaction vector along the back face will shift in the direction from the main cutting edge, thereby creating a moment of rotation of the cutting head. When turning it, a new rear angle is formed, already between the blunt pad and the bottom plane, thereby reducing the friction pad along the rear face. Within the limits of rotation limits, the cutting head will automatically orient itself towards the vector of the resultant downhole reaction, thereby reducing friction losses and cutting and feeding forces.

For a mining combine, the ratio of the feed rate and the speed of rotation of the executive body, as well as the coordinates of the instantaneous location of the cutter along the length of the crescent chips, determine the direction of the vector of the resultant face reaction; the cutter of the claimed design will automatically orient itself against the aforementioned vector, while friction losses and specific energy consumption of cutting will be minimized.

For a plow cutting tool, especially when planing with relatively large thicknesses of the cut, the vector of the resultant downhole reaction changes more significantly, since in some areas there are pulling forces along the front face. In this case, an increase in the blunting area of the incisors leads to a loss of productivity, which is typical for the free supply of plow installations / 3 /.

The claimed technical solution provides a relatively lower growth rate of the blunting pad with an increase in the friction path, and, therefore, blunting of the cutters will have a lesser effect on reducing productivity.

Thus, the positive qualities are proved:

a) to increase the resistance of the cutters, in particular resistance to shock loads on the front face;

b) to reduce the intensity of the drop in productivity associated with blunting of the incisors;

c) to reduce the effect of the friction component on the cutting force, feed force, traction force.

Information sources

1. Mountain tools. M.G. Krapivin, I.Ya. Rakov, N.I. Sysoev. [Text] / M.G. Krapivin and others. M .: Nedra, 1990, p. 32, Fig. 2.7., Cutter PC1.RS2.

2. The collection "Mining and oilfield engineering" [Text] / Volume 5. "Nedra", 1978, p.146.

3. Karabanov M.G., Kalmykov S.D., Kotov E.P. “On the influence of incisor designs on blunting sites” [Text] / M.G. Karabanov and others. On Sat “Technology and Technique for Anthracite Excavation”, issue 12, Shakhty, Shakht-NIUI, 1978, p. 80-93.

Claims (1)

Mining tool including a holder, a cutting head fixed to a holder, a mounting unit for a cutting head on a holder, characterized in that the holder in the mating part with the cutting head is made in the form of a wedge, so that the top of the wedge-shaped part of the holder has the shape of a cylindrical surface with a radius R, the generatrix of which is perpendicular to the side faces of the cutting head and the axis of the cutting tool, and the cutting head is made in the form of a hollow trihedral prism, in which one of the ribs is a cutting edge, and between two other ribs made a hole in the wedge-shaped cavity, and the remote edge of this cavity has the form of a cylindrical surface with a radius R, forming this surface perpendicular to the side faces, while the narrowing angle of the wedge-shaped cavity of the cutting head is 5-10 ° greater than the sharpening angle of the wedge-shaped part of the holder the cutting head and the holder are mated on cylindrical surfaces with a radius R, and the fastening of the cutting head on the holder is provided by connecting the wedge-shaped elastic elements with surfaces d Rzhavka and cutting head or a pin pressed into the bore of the holder and facing the slots on the both side faces of the cutter.

Images