IMPROVING THE EFFICIENCY OF MILLING HOLES WITH A SMALL-SIZED TOOL IN THE CONDITIONS OF AUTOMATED PRODUCTION

Abstract

The purpose of the paper. In order to solve the problems of increasing the efficiency of machining operations of small diameter holes by milling, the optimal range of cutting modes and helix pitch for the machining strategy with helical interpolation is established. The reduction of labor intensity and costs of hole machining when treating holes in alloyed corrosion-resistant steels is experimentally confirmed. Research methods. In this paper, the issues of machining blind holes by helical interpolation milling with end cylindrical carbide cutters of relatively small dimensions in parts made of 12X18N10T alloy are considered. The features of this machining are availability of significant axial and radial components of the cutting forces with relatively low tool strength. This leads to the fact that a key factor of the tool failure is its mechanical failure, the cause of which is an increase in cutting forces due to the edge of the cutter being chipped. Research results and novelty. It has been experimentally proved that the most rational machining parameters to ensure the specified accuracy and surface quality of the machined holes when using a strategy of helical interpolation milling will be the choice of the helix pitch p = 0.2 mm, the feed range F = 0.075-0.11 mm /tooth, which corresponds to the minute feeds of the milling center 450-675 mm/min. Conclusions. The optimal range of cutting modes is found in the feed range from 450 to 675 mm/min, with a helical interpolation pitch of 0.2 mm. The accuracy and roughness of the holes obtained by milling with end mills with a diameter of 3 mm for steel 12X18N10T is evaluated.