【作者】 张红杏；

【导师】 曹利新；

【作者基本信息】 大连理工大学 ， 精密仪器与机械， 2008， 硕士

【摘要】 空间分度凸轮机构具有结构紧凑、刚性好、传动精度高、可实现各种运动规律等优点，被广泛应用于各种自动机械和自动生产线上。本文针对弧面分度凸轮机构工作廓面是不可展面的特点和传统空间凸轮廓面等价加工方法存在的不足，着重研究了弧面分度凸轮机构的五坐标加工刀位规划方法。首先用共轭曲面理论和微分几何的包络理论，结合矩阵变换知识，推导出弧面分度凸轮的廓面方程。用MATLAB的绘图功能，得到了凸轮工作廓面的形状，在此基础上，分析了凸轮廓面的曲率，为刀位规划时选择刀具提供依据。在粗加工刀位规划阶段，利用三点偏置法求得刀具轴迹面上的点，并用准线为B样条曲线的直纹面来拟合刀具的轴迹面。然后建立拟合曲面和设计曲面等距面间的误差平方和最小为目标的最小二乘法模型，优化B样条的控制点以得到质量更好的刀具轴迹面。在精加工刀位规划阶段，采用两重包络法对凸轮廓面进行无理论几何误差刀位规划，并对刀具轨迹进行处理以避免空刀现象，从而防止加工过程中振动的出现。最后，用具体算例验证了所选方法的合理性和所得刀位的正确性。更多还原

【Abstract】 Because of the advantages such as compact configuration, high rigidity, high precision and no restriction on follower motion laws, globoid cam mechanisms are widely used in automatic machinery and automatic production lines.Aiming at the character of globoid indexing cam’s skew surface and the inefficiency of traditional manufacture method, this dissertation is focused on solving complex 5-axis NC machining process by taking the example of globoid indexing cam.Based on the theory of conjugating surfaces, the surface envelope theory of differential geometry and transformation matrix operator methods, the profile equation of the globoid indexing cam and the curvature of the globoid indexing cam have been derived. The figures of the globoid indexing cam’s skew surface are generated by utilizing the MATLAB software.Consequently, For the cam’s rough machining, the position and the orientation of the cutter’s axis are obtained by using the TPO (three points offset). A new NC tool-path planning method has been given based on the least square optimization method and B-spline curve theory, which plays an important role in improving the precision of the cam’s NC machining. For the finishing machining of globoid indexing cam, double envelope method without error in theory is used and special measures are taken to avoid undercutting and vibrating of the machining process.In the last, the process of NC machining is simulated by using the UG software and theCLData (cutter location data) are verified.更多还原