DRILL Russian patent published in 2013 - IPC B23B51/00 

FIELD: process engineering.

SUBSTANCE: invention relates to machine building and may be used for boring complicated parts, for example automotive engine components. Proposed drill comprises cylindrical body with chip removal flute made at body outer side to extend from body working end surface to rear end surface. Chip removal flute inner surface facing front side in direction of drill rotation is furnished with, at least, one extra flute to extend from body working end surface to rear end side. Chip removal flute inner surface facing front side in direction of drill rotation and, at least, on surface of one extra flute form front surface. Side surface of working end is formed on body working end surface. Cutting edge is formed at rib whereat working end side surface crosses front surface. Chip removal flute inner surface facing front side in direction of drill rotation features stepped shape with, at least, one steeped section nearby front surface. Extra flute rear end side has flexed section bent in other direction of flexed section at chip removal flute rear end side.

EFFECT: higher efficiency of chip removal and drill durability.

13 cl, 9 dwg