The design of chip breaking grooves for spade drill inserts

A chip breaking groove was designed on a spade drill insert to break chips. The effects of the anti -chip angle, width and height of chip breaking groove on the chip curl radius were investigated with simulations and drilling experiments. The forces acting on the chip were analyzed to clarify the chip breaking processes. The chip breaking process of a spade drill insert with chip breaking groove was simulated with the finite element technique to study the chip breaking mechanism. The calculation formulas for calculating the width, height and radius of the chip breaking groove were established. The research results show that the chip curl radius is affected by the chip breaking groove parameters. The chip curl radius increases with the anti -chip angle but decreases as width decreases or height increases. When the values of anti -chip angle, width and height of chip breaking groove reach thresholds, the chip wind or piling phenomenon will occur during the drilling experiments. The formulas for calculating chip breaking grooves are feasible. A design method of chip breaking grooves for spade drill inserts is proposed. Spade drill inserts whose chip breaking groove parameters are calculated according to formulas of the width, height and radius can effectively break chips at different drilling parameters.