覆盖件模具曲面曲率特征对球头刀铣削力的影响

发布时间：2019-03-13 11:12

【摘要】：针对自由曲面模具的铣削加工,提出一种综合考虑曲面曲率、刀具前倾角和侧偏角的瞬时铣削力预报方法。基于曲面几何特征,研究了进给方向、行距方向曲率半径对刀具切削角度的影响,以及刀具前倾角和轴向切触角对未变形切屑厚度的影响;基于微分思想,将自由曲面加工中任意刀齿切削周期内的切触区进行离散,结合三维次摆线切削轨迹建立未变形切屑模型,得到适合于自由曲面三轴球头铣削的瞬态铣削力,该模型能够综合考虑曲面曲率特征变化、刀具工件切触角度变化;基于二次曲面模具模型进行铣削加工试验,试验测试结果表明,预报的铣削力和试验测量结果在幅值上和变化趋势上具有一致性,在平稳切削时最大铣削力预测误差值在12%以内,验证了该方法能有效地预报自由曲面模具的球头铣削的瞬态铣削力。
[Abstract]:In view of the milling process of free-form surface die, a method of predicting the instantaneous milling force is presented, which takes into account the curvature of the surface, the inclination of the tool forward and the angle of the side deviation. Based on the geometric characteristics of the surface, the effects of the feed direction and the line spacing radius of curvature on the cutting angle of the tool and the influence of the forward angle and the axial contact angle of the tool on the thickness of the undeformed chip are studied. Based on the differential theory, the cutting contact region of any cutter tooth in the free-form surface machining is discretized, and the undeformed chip model is established by combining the three-dimensional subcycloidal cutting trajectory, and the transient milling force suitable for the three-axis ball head milling of the free-form surface is obtained. The model can take into account the curvature characteristics of the surface and the contact angle of the tool workpiece. The milling test based on Quadric mold model is carried out. The experimental results show that the predicted milling force is consistent with the measured results in amplitude and trend. The prediction error of maximum milling force in steady cutting is less than 12%, which proves that this method can effectively predict the transient milling force of ball-end milling of free-form surface die.
【作者单位】：哈尔滨理工大学高效切削及刀具国家地方联合工程实验室;
【基金】：国家自然科学基金重点资助项目(51235003,51675146)
【分类号】：TG54

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