数控转台弧面凸轮传动设计与仿真分析

发布时间：2018-03-27 17:09

本文选题：弧面凸轮　切入点：数控转台　出处：《集美大学》2015年硕士论文

【摘要】：随着社会的发展和科技的进步,数控机床的应用和普及也越来越广泛,数控转台作为数控机床的核心功能部件之一,其性能的高低对数控机床的整体加工精度影响较大,改进数控转台的传动机构使其具有重载、高速、高效率、动态性能良好等特点已经成为当下研究的热点。因弧面凸轮具有承载能力强,传动精度高等特点受到广泛应用,将弧面凸轮应用于数控转台传动对改善和提高转台的传动特性具重要的理论研究意义和实际应用价值。本文以数控转台作为研究对象,针对牧野卧式加工中心的T2型数控转台,将弧面凸轮应用于该型数控转台的传动设计中。首先对弧面凸轮结构的主要尺寸进行设计,然后在UG软件中对其进行三维实体建模并导入有限元软件中进行静力分析和模态分析,最后对弧面凸轮机电耦合动力学特性进行了研究,主要研究内容和工作成果如下:(1)根据弧面凸轮传动特点,采用回转变化张量法对弧面凸轮的工作廓面矢量方程、空间啮合方程、压力角和接触应力等进行了推导,并且根据数控转台的实际工作参数选定传动方案和电机,然后以推导的压力角和接触应力为约束设计条件,确定了弧面凸轮的主要结构尺寸,同时结合推导的压力角公式,讨论分析了结构尺寸参数对压力角的影响,指出了减小压力角的方法。(2)根据推导的工作廓面矢量方程和空间啮合方程,采用UG软件对弧面凸轮进行了三维实体建模,同时为了便于比较,分别给出了圆柱滚子和圆锥滚子两种弧面凸轮的实体模型,并通过对两种类型弧面凸轮的运动仿真分析验证了模型建立和装配的正确性。(3)采用ANSYS Workbench对圆柱滚子和圆锥滚子两种类型弧面凸轮进行有限元分析,分析在施加相同载荷情况下弧面凸轮的变形、应变和应力特性,结果发现存在较大应力的位置均为凸轮与转动盘滚子接触处,该情况与弧面凸轮实际工作状况相符合,验证了弧面凸轮静力分析的装配约束和载荷加载的正确性。对比两种类型的弧面凸轮静力特性,结果表明圆锥型滚子弧面凸轮的最大应力值399.21MPa要小于圆柱型滚子弧面凸轮的最大应力值425.14MPa,其静力学特性要优于圆柱型弧面凸轮,承载能力也更强,同时为了避免共振形成的过大应力,对弧面凸轮进行了模态分析并给出了相应的固有频率和振型。(4)采用联合仿真的方法在ADAMS和Matlab/Simulink软件中对弧面凸轮的机电耦合动态特性进行研究,通过对弧面凸轮角速度,角加速度和接触应力的仿真曲线分析可以确定弧面凸轮满足数控转台连续传动的要求,并且转动盘运动规律与控制要求一致,证明所设计的弧面凸轮是可行的。对比PI控制前后的曲线,结果表明采用PI控制后的弧面凸轮受力情况和传动平稳性均得到较大改善。
[Abstract]:With the development of society and the progress of science and technology, the application and popularization of CNC machine tools are more and more extensive. As one of the core functional components of CNC machine tools, the performance of CNC turntables has a great impact on the overall machining accuracy of CNC machine tools. Improving the transmission mechanism of the CNC turntable has become a hot topic in the present research field because of its characteristics of heavy load, high speed, high efficiency, good dynamic performance, etc. The globoidal cam has been widely used because of its strong bearing capacity and high transmission precision. The application of globoidal cam to the transmission of NC turntable has important theoretical research significance and practical application value in improving and improving the transmission characteristics of the turntable. This paper takes the NC turntable as the research object, aiming at the T2 type NC turntable in the Muye horizontal machining center. The globoidal cam is applied to the drive design of the CNC turntable. Firstly, the main dimensions of the globoidal cam structure are designed. Then the 3D solid modeling is carried out in UG software, and the static analysis and modal analysis are carried out in the finite element software. Finally, the electromechanical coupling dynamic characteristics of the globoidal cam are studied. The main research contents and results are as follows: (1) according to the characteristics of globoidal cam transmission, the working profile vector equation, space meshing equation, pressure angle and contact stress of the globoidal cam are derived by using the rotating variable Zhang Liang method. According to the actual working parameters of the CNC turntable, the transmission scheme and motor are selected, and then the main structural dimensions of the globoidal cam are determined under the constraint design conditions of the derived pressure angle and contact stress, and the pressure angle formula is combined with the derived pressure angle formula. The influence of structural dimension parameters on pressure angle is discussed and analyzed. The method of reducing pressure angle is pointed out. According to the working profile vector equation and space meshing equation derived, the 3D solid modeling of globoidal cam is carried out with UG software. At the same time, for the sake of comparison, the solid models of two kinds of globoidal cam, cylindrical roller and conical roller, are given respectively. Through the simulation analysis of two types of globoidal cam, the correctness of the model establishment and assembly is verified. The finite element analysis of cylindrical roller and conical roller is carried out by using ANSYS Workbench. The deformation, strain and stress characteristics of the globoidal cam under the same load are analyzed. The results show that the position of the greater stress is the contact between the cam and the roller of the rotary disc, which is consistent with the actual working condition of the globoidal cam. The correctness of assembly constraint and load loading of globoidal cam static analysis is verified. The static characteristics of two types of globoidal cam are compared. The results show that the maximum stress value of the tapered roller globoidal cam 399.21MPa is smaller than the maximum stress value of the cylindrical roller globoidal cam 425.14 MPa, and its statics characteristic is better than that of the cylindrical globoidal cam, and its bearing capacity is also stronger. At the same time, in order to avoid the excessive stress caused by resonance, The modal analysis of globoidal cam is carried out, and the corresponding natural frequency and mode type are given. By using the method of joint simulation, the electromechanical coupling dynamic characteristics of globoidal cam are studied in ADAMS and Matlab/Simulink software, and the angular velocity of globoidal cam is studied. The simulation curve analysis of angular acceleration and contact stress can determine that the globoidal cam can meet the requirements of continuous transmission of NC turntable, and the motion law of the rotary disc is consistent with the control requirement. It is proved that the designed globoidal cam is feasible. Compared with the curve before and after Pi control, the results show that the force situation and the driving smoothness of the globoidal cam after Pi control are improved greatly.
【学位授予单位】：集美大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG659

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