径向跳动对球面铣刀切削力的影响研究

研究了径向跳动对刀齿的实际切削半径、切屑形状以及切屑厚度的影响机理。研究了各刀齿沿刀刃螺旋线的切削微元实际切削半径的数学表示和变化规律,实际切削半径的变化改变了刀齿的切削路径,使各刀齿上切屑形状分布不均匀。建立了三维切削下切屑厚度的数学表示,提出了递延累加切屑厚度计算算法。实验验证表明,计算的切削力与测量结果能很好地吻合,瞬时切削力、切削力峰值、平均切削力的预测精度达到85%以上。

Study on Effects of Cutter Runout on the Cutting Force in Ball-End Milling

The mechanism of impacts of cutter runout on the pratical cutting radius,chip form and chip thickness was studied and analyzed.A mathematical expression and the effective rules of practical cutting radii of the cutting elements along the helix cutting edge were studied.The variable practical cutting radius changed the cutting path of the cutter,thus caused unbalanced chip form of each cutting edge.The calculation formula of the chip thickness was established under 3D cutting process and an uncontinuable adding up calculation algorithm of the chip thickness was proposed.At last,this cutting force model was verified through several cutting tests under different cutting conditions.The test results show that predicted cutting forces fit close to the measured ones,and the predicted accuracy of the instantaneous cutting forces,peak cutting force and average cutting force are increased to 85%.