General modeling and calibration method for cutting force prediction with flat-end cutter
General modeling and calibration method for cutting force prediction with flat-end cutter
复制标题
平端铣刀切削力预测的通用建模与标定方法
DOI：
10.1115/1.4038371
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Zhao Wanhua
中科院分区：
文献类型：
--
作者：
Zhang Xing;Zhang Wei;Zhang Jun;Pang Bo;Zhao Wanhua
提出了一种用于平头刀具的刀具跳动和比切削力系数的通用标定方法，建立了较高精度的周向铣削切削力预测方法。本文综合考虑了大刀轨曲率时的刀具跳动、底刃切割效应和有限制的实际进给速度。首先，基于摆线运动建立了齿面轨迹模型，提出了描述刀具/工件啮合的瞬时未切屑厚度(IUCT)解析模型。其次，提出了一种考虑偏移量和倾斜量的刀具跳动非接触识别方法，该方法利用相邻齿间的切割半径相对变化量构造目标函数，通过数值优化方法进行识别。第三，基于改进的薄板铣削实验，详细介绍了考虑底刃切割效应的超临界流体力学性能的三步标定方法。最后，进行了一系列铣削试验，验证了该方法的有效性。结果表明，该方法既适用于等螺距刀具，也适用于变螺距刀具，并证明了该方法的通用性。此外，本文还指出，刀具跳动对主轴转速具有很强的依赖性，刀具轴向的铣削力存在方向切换现象，实际进给速度将受到较大的刀具轨迹曲率的限制。为了获得准确的铣削力预测，应综合考虑所有这些因素。
A general calibration method of cutter runout and specific cutting force coefficients (SCFCs) for flat-end cutter is proposed in this paper, and a high accuracy of cutting force prediction during peripheral milling is established. In the paper, the cutter runout, the bottom-edge cutting effect, and the actual feedrate with limitation during large tool path curvature are concerned comprehensively. First, based on the trochoid motion, a tooth trajectory model is built up and an analytical instantaneous uncut chip thickness (IUCT) model is put forward for describing the cutter/workpiece engagement (CWE). Second, a noncontact identification method for cutter runout including offset and inclination is given, which constructs an objective function by using the cutting radius relative variation between adjacent teeth, and identifies through a numerical optimization method. Thirdly, with consideration of bottom-edge cutting effect, the paper details a three-step calibration procedure for SCFCs based on an enhanced thin-plate milling experiment. Finally, a series of milling tests are performed to verify the effectiveness of the proposed method. The results show that the approach is suitable for both constant and nonconstant pitch cutter, and the generalization has been proved. Moreover, the paper points out that the cutter runout has a strong spindle speed-dependent effect, the milling force in cutter axis direction exists a switch-direction phenomenon, and the actual feedrate will be limited by large tool path curvature. All of them should be considered for obtaining an accurate milling force prediction.