大型丝杠的旋风铣削加工工艺优化研究

【作者】 常学峰；

【导师】 李迎；

【作者基本信息】 南京理工大学 ， 机械制造及其自动化， 2012， 硕士

【摘要】 硬铣削加工(即旋风铣削加工)是二十世纪中后期产生的一种新型切削加工方式,因其高效、优质、低耗、清洁等优势成为切削加工的主流方式,被广泛地运用到螺纹及丝杠的切削加工中。本文以提高大型丝杠的旋风铣削加工精度为目的,通过理论建模与有限元仿真的方法研究大型丝杠的旋风铣削加工过程,并对其加工工艺进行优化。针对大型丝杠刚度低的问题,建立了多支撑下的大型丝杠的旋转动力学模型,且在建模的过程中考虑丝杠旋转速度,丝杠自重对大型丝杠旋转动力学研究的影响。运用有限元仿真技术与MATLAB中的遗传算法工具箱对支撑布局进行优化。对大型丝杠的旋风铣削加工工艺优化的方法进行了研究。由于粒子群算法收敛速度快、核心程序简单、涉及学科知识少等优点,重点研究了粒子群算法并编写了粒子群算法程序。针对粒子群算法存在的缺陷,提出了基于随机方向法的粒子群算法(RDM-PSO)来弥补该缺陷。通过测试函数分析及与其它文献对比,对基于随机方向法的粒子群算法的算法性能进行了研究,并将其运用到大型丝杠的支撑布局再优化中。建立了大型丝杠旋风铣削加工的瞬时切削厚度模型,刀-屑接触长度模型,并基于高速切削加工理论,建立了大型丝杠旋风铣削加工的切削力理论模型,同时通过有限元切削仿真,得到不同旋风铣削加工参数,不同刀具结构下的旋风铣削力、表层残余应力、切屑形态等。建立大型丝杠在沿轴向移动的断续旋风铣削力作用下的动力学模型,通过使用wilson-θ法求解此模型得到不同旋风铣削工况下的大型丝杠的动力学响应,同时在ABAQUS中,对大型丝杠旋风铣削加工模型进行模态动态分析得到大型丝杠的动力学响应,且在MATLAB数值模拟与有限元模态动态分析的过程中,考虑大型丝杠的旋转速度、自重,铣刀盘的轴向进给速率,断续旋风铣削力,夹紧力对大型丝杠动力学响应的影响。最后,将大型丝杠在沿轴向移动断续旋风铣削力作用下的动力学响应值作为目标函数,使用基于随机方向法的粒子群算法与MATLAB遗传算法工具箱对旋风铣削加工参数进行优化。更多还原

【Abstract】 Hard whirling is a new manufacturing method which is discovered by the middle of 20 century. It is famous for its high quality, high efficiency, low-consuming, clearness, and has been intensively used in screw and ball screw manufacturing. In this article, we aim at improve the machining accuracy of large ball screw. Meanwhile, we use theoretical modeling and finite element analysis to optimize the manufacturing process.Firstly, in order to increase the rigidity of large ball screw, we build the dynamic equation of large ball screw under supports, taking consider of rotating speed and gravity of large ball screw, and use Genetic Algorithm toolbox in MATLAB and Finite element analysis to optimize the layout of supports.Secondly, do research about the method to optimizing manufacturing process which is called optimization algorithm. Because Particle Swarm Optimization algorithm has fast convergence efficiency, simple procedure, little subject involved and so on, so in this article we are mainly focus on it, what’s more, we improve the performance of Particle Swarm Optimization algorithm through adding Random Direction Method into it, and we use RDM-PSO to optimize the layout of supports again.Thirdly, modeling the minimum chip thickness, the instantaneous chip thickness and tool-work contact length, and theoretically build the whirling force model according to high speed metal cutting theory, meanwhile study whirling force, surface residual force, chip shape under different whirling condition and the structure of cutter through metal cutting simulation in ABAQUS.Fourthly, build the dynamic equation of rotating large ball screw under axially moving interrupted whirling force, solving this equation and doing dynamic modal analysis of large ball screw under whirling in ABAQUS to get ball screw’s deflection, taking consider of the rotating speed and gravity of ball screw, axially moving interrupted whirling force and clamping force.Finally, we consider the deflection of ball screw under axially moving interrupted whirling force as objection function, and use RDM-PSO and GATO to optimize the whirling parameter.更多还原