BTA钻杆—工件系统耦合涡动行为及控制方法研究

发布时间：2018-01-20 04:23

本文关键词： BTA 涡动应变传感器模糊模型 Simulink　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：生产技术发展迅速的今天,深孔加工技术更多的应用于航天、兵器、高铁等高精度要求的制造中。但是,深孔加工由于其长径比大的原因,在加工过程中,钻杆存在着主动振动和旋转的涡动,这些现象破坏被加工孔的表面质量,如:表面光洁度、几何尺寸和公差等。由此,可知深孔加工是机械制造行业中工艺最为复杂、价格最为昂贵的钻孔工艺。本文针对BTA深孔加工过程中钻杆-工件的涡动现象,进行了以下几方面的工作:基于流体动压润滑理论和梁的固有振动方程,建立了钻杆-工件系统横向振动方程,并考虑高压切削液对钻杆加工段的扰动,完善了钻杆-工件系统横向振动微分方程,最后依据振动理论的求解方法对动力学微分方程进行了求解,该微分方程中包含一对控制激励。设计了基于应变传感器的钻杆横向位移检测装置,设计了三个实验:实验一,在钻杆自由旋转的情况下对钻杆的横向位移进行测量。实验二,在钻孔的初始阶段对钻杆的横向位移进行测量,并绘制出了钻杆在不同转速下的中心轨迹图。实验三,设置不同的转速、进给量、切削液流量进行钻孔,并对被加工孔件进行直线度、表面粗糙度测量。依据实验三测得的直线度和表面粗糙度进行误差计算,提出了用模糊逻辑模型进行的离线操作模型,该模型可用来测量实验中获得的结果,且可预测所需获得表面质量的最佳切削参数组合。根据运动微分方程,运用MATLAB/Simulink软件建立仿真控制模型,给出了在不同控制位置,以及不同控制激励下钻杆的涡动特性。研究结果表明:BTA深孔加工中的钻杆受多方面影响而发生涡动、横向振动,基于应变位移传感器的横向位移测量装置可以准确的测量钻杆的横向位移,所绘制的钻杆中心轨迹图可以反映出数学模型的正确性。基于模糊逻辑的离线操作模型可以很好的预测所需获得表面质量的最佳切削参数组合。在某一转速下,外界控制激励的位置不同、激励类型不同,都会对钻杆的涡动抑制效果产生不同的影响。因此,本文较为详尽的对钻杆的涡动现象进行了阐述,并提出了相应的控制方法,具有实际意义。
[Abstract]:With the rapid development of production technology, deep hole processing technology is more used in aerospace, weapons, high-speed iron and other high-precision manufacturing. However, deep hole processing because of its large aspect ratio, in the process of processing. There are active vibration and whirling of drill pipe, which destroy the surface quality of the machined hole, such as surface finish, geometric dimension and tolerance. Deep hole machining is the most complicated and expensive drilling technology in mechanical manufacturing industry. This paper aims at the vortex phenomenon of drill pipe and workpiece in the process of BTA deep hole machining. Based on the hydrodynamic lubrication theory and the inherent vibration equation of the beam, the transverse vibration equation of the drill pipe and workpiece system is established, and the disturbance of the high pressure cutting fluid to the drill pipe machining section is considered. The differential equation of lateral vibration of drill pipe and workpiece system is improved. Finally, the dynamic differential equation is solved according to the vibration theory. The differential equation includes a pair of control excitations. A drill pipe lateral displacement detecting device based on strain sensor is designed. Three experiments are designed: experiment 1. The lateral displacement of drill pipe is measured under the condition of free rotation of drill pipe. In experiment two, the lateral displacement of drill pipe is measured in the initial stage of drilling. The center track diagram of drill pipe under different rotating speed is drawn. Experiment 3, set different rotation speed, feed rate, cutting fluid flow rate to drill hole, and carry on straightness to the processed hole parts. Surface roughness measurement. Based on the error calculation of straightness and surface roughness measured in experiment 3, an off-line operation model based on fuzzy logic model is proposed, which can be used to measure the results obtained in the experiment. According to the motion differential equation, the simulation control model is established by using MATLAB/Simulink software, and the different control positions are given. As well as the vortex characteristics of drill pipe under different control excitation. The results show that the drill pipe in the deep hole machining of BTA is affected by many aspects of vortex and lateral vibration. The lateral displacement measurement device based on strain displacement sensor can accurately measure the lateral displacement of drill pipe. The trajectory diagram of drill pipe center can reflect the correctness of mathematical model. The off-line operation model based on fuzzy logic can well predict the optimal cutting parameters combination of surface quality. Different positions of external excitation and different types of excitation will have different effects on the vortex suppression effect of drill pipe. Therefore, the vortex phenomenon of drill pipe is described in detail in this paper. The corresponding control method is put forward, which is of practical significance.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG523

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