Abstract: The chip evacuation performance of the drill directly affects the cutting performance.In order to address the issues of chip entanglement and vibrations encountered during the cutting process of indexable insert drills,and to prevent resulting processing abnormalities and poor hole wall quality,a combination of theoretical analysis and simulation was utilized to conduct an in-depth study on the impact of the cross-sectional shape and helix angle structure of the chips flute on the drill body rigidity.Experimental validation was conducted to demonstrate the excellent rigidity and chip evacuation performance of the designed drill.Simulation experimental results analysis showed that when the core diameter is consistent,the maximum stress on the drill body is 761 MPa,the strain is 0.003 367,the drill body head lateral displacement is 0.397 1 mm,and the rotation change is 0.006 500 rad;when the variable helix angle is between 20°-16°,the maximum stress on the drill body is 695 MPa,the strain is 0.002 688,the drill body head lateral displacement is 0.364 1 mm,and the rotation change is 0.006 140 rad,achieving a good balance between drill body rigidity and chip evacuation performance.The analysis indicates that as the helix angle increases,the difference in leaf width increases,and the core diameter decreases,the drill body rigidity becomes poorer. The designed drill demonstrated better chip evacuation performance without chip entanglement under experimental conditions,and exhibited high hole diameter consistency and good hole wall quality.

Key words: indexable insert drill, chip flute, rigidity, cross-sectional shape, helix angle