RU2018659C1 - Mining machine cutter for cutting, mainly, hard rocks - Google Patents

Abstract

FIELD: mining. SUBSTANCE: cutter has holder with shank, symmetrical working head with hard-alloy insert secured in its socket. Insert-includes head with pointed apex and cylindrical body. Generating line of side surface of hard-alloy insert head has shape of arc of circle whose center is located at intersection of normal with tangent to circle arc in pointed apex of hard-alloy insert head and body base of hard-alloy insert. Beginning of circle arc forming side surface of head of hard-alloy insert is located in pointed apex of hard-alloy insert head. EFFECT: higher efficiency. 2 dwg

Description

 The invention relates to the mining industry, in particular to the design of a cutting tool for use in cutting actuators of tunneling combines and mechanized tunneling shields, mainly for the destruction of strong rocks.

 Known cutters, consisting of a holder with a shank, a conical head part and a carbide insert fixed in the socket of the working conical head [1 and 2].

Carbide insert these cutters has a cylindrical shape and a conical tip with a taper angle at the vertex ^of 70-90.

A disadvantage of cutters having carbide inserts with straight taper at the top, is the low strength of the conical head insert at relatively small angles of taper ^of up to 70-75. When such cutters work in rocks with strong rock inclusions, the top of the carbide insert is first destroyed, and then the entire cutting head of the carbide insert is intensively destroyed.

As the angle of taper at the top of a ^75-80 markedly reduced height ( "Departure") of the active part of the cutting insert, and at least its wear upon contact with the rock sharply blunting pad on the back side, which leads to a marked increase the cutting forces and heat insert, and therefore contributes to intensive wear and destruction of the cutter.

 The aim of the invention is to increase the strength and wear resistance of the cutter when working on rocks of high strength due to more advanced geometry of the cutting part.

где К=1,5-1,6 - эмпирический коэффициент;
d_в - диаметр корпуса твердосплавной вставки, м;
α_в - угол заострения головки твердосплавной вставки, град.,
при этом началo дуги окружности, образующей боковую поверхность головки твердосплавной вставки, расположено в вершине угла заострения головки твердосплавной вставки.This goal is achieved by the fact that the generatrix of the side surface of the head of the carbide insert has the shape of a circular arc, the center of which is located at the intersection of the normal to the tangent to the circular arc at the apex of the sharpening angle of the head of the carbide insert and the base of the carbide insert body, and whose radius r is determined from the expression
r =

where K = 1.5-1.6 is an empirical coefficient;
d _in - the diameter of the carbide insert body, m;
α _in - the angle of sharpening of the head of the carbide insert, deg.,
at the same time, the beginning of the arc of the circle forming the side surface of the head of the carbide insert is located at the apex of the angle of sharpening of the head of the carbide insert.

 In FIG. 1 shows a General view of the proposed cutter; figure 2 - the working head of the cutter with a carbide insert.

 The cutter consists of a holder 1 with a shank 2, a symmetrical working head 3 and a carbide insert 4 located in the socket of the working head, which has a cylindrical-shaped body 5.

In a carbide insert, the cutting part — head 6 — has a predetermined point angle at apex α _in and a height h _in from the base of the insert body to the top of the point angle. The lateral surface of the head of the carbide insert has the shape of a circular arc and is formed by rotating an arc of radius r with a center at point O, which is located at the intersection of the normal O-a to the tangent drawn to the arc of the specified circle at the apex of the angle of sharpness of the head, and the continuation of the cylindrical base of the insert.

где К=1,5-1,6 - эмпирический коэффициент, значение которого известно и определяется как соотношение K ≈

, ,
h_в - высота вставки, м;
d_в - диаметр корпуса вставки, м.The radius r of the circle is determined from the expression
r =

where K = 1.5-1.6 is an empirical coefficient, the value of which is known and is defined as the ratio K ≈

,,
h _in - insertion height, m;
d _in - the diameter of the insert, m

 The beginning of the arc of a circle forming the side surface of the head of the carbide insert is located at the apex of the angle of sharpening.

The cutting head of the carbide insert of the described form, turning into a truncated cone or cylindrical surface at the base, has a sharpening angle gradually decreasing from the top to the base, and at the apex, the angle α _in is a given rational value. Such a structural embodiment of the cutter increases the strength and wear resistance during the destruction of strong rocks.

Claims (1)

CUTTER OF THE MINING MACHINE FOR DESTRUCTION OF PREVIOUSLY STRONG BREEDS, including a holder with a shank, a symmetrical working head with a socket for accommodating a carbide insert and a carbide insert fixed in the socket of the working head, containing a head with a sharp point at the apex and a cylindrical body shape, characterized in that the head of the carbide insert has the shape of a circular arc, the center of which is located at the intersection of the normal to the tangent to the circular arc at the apex of the pointed angle the head of the carbide insert and the base of the body of the carbide insert, and the radius r of which is determined from the expression
r =

where K = 1.5 - 1.6 is an empirical coefficient;
d _in - the diameter of the carbide insert body, m;
α _in - the angle of sharpening of the head of the carbide insert, deg,
wherein the beginning of the arc of a circle forming the side surface of the head of the carbide insert is located at the apex of the angle of sharpening of the head of the carbide insert.

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