Peculiarities Regarding the Smooth Entrance of the Drill in Cutting When Processing Steel

Abstract

Metal drilling is one of the most common methods of obtaining cylindrical bores. At the same time, the drill is the cutting tool that cuts in the most difficult conditions and consequently any measure that leads to the improvement of the cutting process is useful. The smooth entrance in the cutting is a way to increase the durability of the drill and consequently specific devices have been developed. One of these devices is shown in this paper and previous research shows the effectiveness of its use in drilling. The analysis of the device shows that it is used for cutting 41MoC11 and C45 steels with high speed steel drills, which are in a small range of sizes. The active element of the device is identified, a helical spring working for compression, and by calculating the respective axial force of the torque, is determined exactly the range of diameters of the drills that can cut effectively. At the same time is analyzed the way of enlarging the range of drills used with the device for smooth entrance in cutting, by introducing a second spring, concentric with the first, and which works simultaneously with it, thus the device was reengineered.