无心车床导向机构系统的特性分析

发布时间：2018-10-14 20:08

【摘要】：无心车床是一种高效切削金属棒材的机床,主要针对于金属棒材的外圆进行切削加工,获得具有很高的表面粗糙度和较高直线度的金属棒料。近年来,无心车床作为细长金属棒材高效加工设备被广泛的应用,而无心车床导向机构是无心车床的关键部件,在棒料车削过程中对棒材起导向、支撑和夹紧的作用,它的性能直接影响到无心车床整机的加工的质量和效率。本文在ADAMS中建立无心车床导向机构三维模型并进行运动仿真,通过ADMAS后处理软件输出导轮的力学曲线和位移曲线;同时在参数化建模时考虑棒材自重,用MATLAB进行计算棒材弯矩、挠度等,通过对导向机构的优化达到减少拉杆对机体拉伤的目的;此外在ANSYS里得到导向机构的柔性体,并建立关键点后导入ADMAS中进行仿真得到棒材在切削加工时关键位置的加速度,对其工作中的振动情况进行研究,最后通过实验验证理论的正确性。本文得到的结果,为产品的实验、制造、设计、性能改善等提供依据。具体的研究工作内容如下:(1)首先介绍有关无心车床在国内外研究现状、基本结构,并对无心车床导向机构的研究内容和工作过程及其在研究中需要注意的问题做了简单的介绍;(2)利用ADMAS运动仿真软件建立导向机构的三维模型并得到其导向机构滚轮的轨迹曲线和导向机构对棒材的压紧力曲线;(3)建立设计变量,对导向机构的参数化设计和导向机构的优化,由于无心车床导向机构中,其杆件和机体之间所受的拉力可造成杆件的拉伤,通过改变参数的设计的方法来解决拉伤问题,使导向机构单元结构更加合理;(4))利用ADMAS/ANSYS对无心车床导向机构进行运动特性分析,得到在柔性体导向机构关键位置的加速度,利用MATLAB得到其振动位移;(5)搭建实验平台进行实验分析,利用加速度传感器测无心车床加工棒料过程中导向机构单元上关键点的加速度数据,测得的数据在MATLAB中进行处理,两次积分得到关键位置的位移曲线,将实验数据与第四条得出的仿真数据进行对比,由此来验证仿真的正确性。
[Abstract]:Centerless lathe is a kind of machine tool for cutting metal bar with high efficiency. The metal bar with high surface roughness and high straightness can be obtained by cutting the outer circle of metal bar. In recent years, the centerless lathe is widely used as the high efficient processing equipment of slender metal bar. The guiding mechanism of the centerless lathe is the key part of the centerless lathe, which plays a guiding, supporting and clamping role on the bar during the turning process of the bar. Its performance directly affects the machining quality and efficiency of the centerless lathe. In this paper, the three-dimensional model of guide mechanism of centerless lathe is established in ADAMS, and the motion simulation is carried out. The mechanical curve and displacement curve of guide wheel are outputted by ADMAS post-processing software, and the bending moment of bar is calculated by MATLAB when considering the weight of bar in parameterized modeling. Deflection and the like, through the optimization of the guiding mechanism to achieve the purpose of reducing the pull rod to the body, in addition, in ANSYS, the flexible body of the guiding mechanism is obtained. The key points are established and introduced into ADMAS to simulate the acceleration of the key position of the bar in the cutting process. The vibration of the bar in the cutting process is studied. Finally, the correctness of the theory is verified by experiments. The results obtained in this paper provide the basis for the experiment, manufacture, design and performance improvement of the product. The specific contents of the research work are as follows: (1) the current research situation and basic structure of the centerless lathe at home and abroad are introduced. The research content and working process of the guide mechanism of centerless lathe and the problems needing attention in the research are simply introduced. (2) the three-dimensional model of the guiding mechanism is established by using the ADMAS motion simulation software and the rolling of the guiding mechanism is obtained. The track curve of the wheel and the compaction force curve of the guide mechanism to the bar; (3) the design variable is established, For the parametric design of guide mechanism and the optimization of guide mechanism, because of the tension between the rod and the body in the guide mechanism of the centerless lathe, the tensile injury of the rod can be solved by changing the design method of the parameters. (4) using ADMAS/ANSYS to analyze the motion characteristics of the guide mechanism of the centerless lathe, and get the acceleration at the key position of the flexible body steering mechanism. The vibration displacement is obtained by using MATLAB. (5) the experimental platform is built for experimental analysis, and the acceleration data of the key points of the guide mechanism unit in the machining process of the centerless lathe are measured by the acceleration sensor, and the measured data are processed in the MATLAB. The displacement curve of the key position is obtained by two times integration, and the experimental data is compared with the simulation data obtained from the fourth section, which verifies the correctness of the simulation.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG502.3

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