【作者】 李刚；

【导师】 王宏；

【作者基本信息】 兰州理工大学 ， 机械制造及其自动化， 2011， 硕士

【摘要】 目前,数控机床都是以直角坐标方式工作,此技术的基础是通过丝杠螺母机构把伺服电机产生的旋转运动转化成滑板机构的直线运动。当机床加工圆周表面、倾斜表面时,需要借助计算机进行不断的差补运算。通过X、Y方向的伺服电机各自在不同时间段接受指令,驱动机床的执行机构在微观上以走台阶面的形式完成对圆弧、斜线及各种曲线加工。用该方法加工的圆弧、非圆二次曲线的表面只是近似值,而非理论值。在高频率启停、移动的情况下,如果机床的体积较小,其X、Y方向执行机构的移动惯量尚且不大,若机床机床体积较大,那么其执行机构的移动惯量便成为不可忽视的问题。针对直角坐标机床加工二次曲线存在的问题,本课题研究了一种按极坐标轨迹运行的极坐标数控机床。所谓极坐标式数控机床是指在极坐标下数控机床本身具有1个能够实现极角改变的旋转轴和1个能够实现极径改变的径向移动轴,两轴在位置控制模式下可以实现角位移与径向位移的联动。我们把这种机床称为“极坐标式数控机床”。该系列机床不但具有传统数控机床的优点,而且更加适合在极坐标参数下加工大型回转类零件沿环形分布要素,以及复杂曲线、曲面。本文主要从以下几个方面研究设计了该新型极坐标数控机床:(1)按照机床的一般设计规律,设计了机床的总体方案,提出了核心部件的设计方案。同时计算了机床所需要的最大切削功率,确定了机床的主要尺寸参数、技术参数和机床的控制系统方案;(2)围绕机床的设计目标和传动要求,设计出了主箱体结构及其内部的零部件,平旋盘结构及其内部的零部件;(3)对于既作回转运动又作径向直线运动的主轴,提出了其供电、供水系统的技术措施,并设计出了其详细结构图;(4)遵循数控机床传动系统的要求,设计出了机床的回转进给和径向进给传动链,并且研究了两者之间的运动合成算法;(5)运用ANSYS有限元分析软件,分析了机床主要结构件平旋盘轴和平旋盘的静态和动态特性。更多还原

【Abstract】 At present,NC machine tool all works by the way of rectangular coordinates. The foundation of this technology is that throughing screw nut institutions turn motor rotation movement produced by servo motor into straight-line movement of Skateboarding institutions. NC machine tool needs continuously sent filling operation by using computer,When machining the surface of circle and tilt. Arcs,slash and various curve are processed in the form of platform terrace microscopically with the machine executing agencies drived alone by the servo motor in the direction of X and Y,which accept their orders at different times. Under this method,the surface processed of arc and non-circular quadratic curves are just approximate,rather than the theoretical value. In case of high frequency start-stop and mobile,if the volume of machine tool is smaller,the moving inertia of actuators in the direction of X and Y is not great. On the contrary,the mobile inertia became unavoidable issue.According to the problems existed in the processing of quadratic curves,we researched one type of polar NC machine tool,which could operate on the basis of the polar trajectory. The so-called polar NC machine tools is pointed that the NC machine tools itself has one rotating axis which can realize the change of polar angle and one radial mobile axis which can realize the change of extremely diameter under polar coordinates. Both of the axes could achieve linkage of the displacement of radial and angle in the mode of position control. This type of machine tool are called“polar NC machine tool”. This series of machine tools not only have the advantages of traditional NC machine,but also are more suitable for processing the elements distributed along the circular of large rotary parts,as well as complex curve and surface.In this article,we mainly study and design the new kinds of polar NC machine tools from the several aspects followed.(1) According to the traditional design rules,we design the overall project of the machine tool and puts forward the design scheme of core parts. Also calculated the biggest cutting power needed by the machine tools,confirmed the parameters of main size and technical of the machine tools and the scheme of control system.(2) Around the designed goal and transmitted requirements of the machine tools, we designed out the structure and internal components of main body and flat rotary dish. (3) About the spindle that could achieve rotary motion and straight-line movement along radial,we submit the technical measures of system of supplied power and water and design the detailde charts.(4) Following the requirements of driven system of NC machine,we disgn out the feeded transmission chain of rotary and radial,also studied the movement synthetic algorithm between them.(5) Using finite element analysis software of ANSYS,we analyzed the static and dynamic character of shaft and base of flat rotary dish.更多还原