Energy consumption in high-speed hole drilling

The high-speed steel tool life strongly depends on the cutting speed. The development of cutting operations implies solving multiple-criteria optimization problems. In this context, the dependence of energy consumption on the tool life is of particular scientific and practical interest. This paper deals with hole drilling operations. It has been found that the functional failure of drills manifests itself in the form of tooth or tool damage and is preceded by changing the nature of dynamic drilling parameters. A relatively smooth increase of the cutting torque with operation time is interrupted by abrupt busts of the drilling torque comparable with the ultimate strength of the tool. The values of the drilling torque at which the process character changes depend on cutting parameters, diameters of drills and work material properties. They are determined by the experimental coefficient K setting up a correspondence between the tool failure torque and the drilling torque preceding abrupt busts. The dependence of the coefficient K on the main parameters and drilling conditions is established. The relationship between the drilling torque and the tool operation time before failure at different cutting speeds is formulated. This allows determining the drilling power and, consequently, energy consumption. It has been found that the dependence of the energy consumption on the drilling speed is extreme in nature, with the energy consumption and operation time being maximum at the same cutting speed.

References

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