Increasing the efficiency of prefabricated drills and the strength of replaceable cutting inserts

The results of calculating the stress-strain state in replaceable cutting inserts of assembly tools are presented, using the finite element method. In the calculation, the mechanical characteristics of the tool hard alloy were specified, the conditions for the interaction of the replaceable cutting inserts with the drill body, the fastener elements, the force loading was replaced by the specification of the boundary conditions. As a result, a number of basic sizes of replaceable cutting inserts were built, with different geometric parameters. A system of equations for the calculation of cutting forces for drilling with prefabricated drills of different types has been developed. To determine the influence of the shape of the plates on the stressed state, replaceable cutting inserts of different shapes were studied: trihedral, rhombic, square. A new form of replaceable high-strength cutting inserts with an enlarged angle has been developed. To improve performance, the auxiliary cutting edge of the replaceable cutting insert is made in the form of an arc inscribed in a quarter of the length of the side of the polyhedron, while the radius of the curved cutting edge is equal to half the length of the side of the polyhedron. (paper)