Drilling tool for drilling holes in solid metal material, in particular for drilling holes in plate stacks

摘要

In the case of a drilling tool for drilling holes in solid metal material, in particular for drilling holes in plate stacks, two geometrically similar indexable inserts (2, 3) are arranged at different radial spacing and offset by 180@ relative to one another in the circumferential direction on the end face of the shank (1), the working regions of which inserts overlap and each of which has a plurality of equal-length cutting edges (2a, 2b, 3a, 3b). Of the cutting edges (2a, 2b, 3a, 3b), in each case two adjacent cutting edges, inclined at an obtuse angle ( alpha ) to one another, are simultaneously in engagement, in which case the radially inner, first indexable insert (2) passes slightly beyond the drill axis (A) by way of its cutting edge (2b) which is in engagement, and the radially outer, second indexable insert (3) is axially set back with respect to the first indexable insert (1), and its two effective cutting edges (3a, 3b) enclose different-size, acute angles ( beta 1, beta 2) with the drill axis (A). The first indexable insert (2) is made smaller than the second indexable insert (3). A third indexable insert (4), which is also smaller than the second indexable insert (3), is arranged on the same radius as the first indexable insert (2) in such a way that its effective cutting edge (4a) works approximately in the same working cone and on the same maximum radius (R) as the radially outer cutting edge (3a) of the second indexable insert (3). IMAGE