| 摘要 |
A rotationally driven machining tool, especially a drill, having a nominal drill diameter (D) and comprising at least one machining groove (1) and at least one web (2). A main cutting edge (4) and an inner cooling channel (3) are formed on each web (2). Said cooling channel has a continuously extending cross-sectional contour (30; 31; 32; 30X) enclosing an imaginary circle (K) with a center point (M). The cross-sectional contour comprises one, preferably comprises two, maximum curvature value(s) whose distance to the drill axis (A) is greater in the direction of a line between the center point (M) and the drill axis (A) or equal to the distance of the center point (M) to the drill axis (A). Minimum wall thicknesses (dAUX, dSPX, dSFX) exist between the inner cooling channel (3) and the outer periphery of the drill (7), between the inner cooling channel (3) and the machined surface (5) and between the inner cooling channel (3) and the machining surface (6), ranging from a lower threshold (Wmin,1; Wmin, 2,; Wmin,3) and to an upper threshold ( Wmax,1;. Wmax,2; Wmax,3). The lower threshold is 0.08 x D for D<=1 mm and 0.08 mm for D >1 mm (Wmin,1) and the upper threshold is 0.35 x D for D < 6mm and 0.4 x D - 0.30mm for D >6mm (Wmax,1). The radius (R1;R1';R1";R1X) at the highest amount of curvature of the cross section contour (30;31;32;30X) of the internal cooling channel (3) corresponds to 0.35 - 0.9 of the radius (R0) of the circle (K). |
