【作者】 李庆兴；

【导师】 范顺成；

【作者基本信息】 河北工业大学 ， 机械设计及理论， 2009， 博士

【摘要】 轧辊是轧机的重要部件之一,是轧制作业的主要变形模具,其质量直接决定了轧制产品的质量。而异型轧辊属于非圆截面零件,由于其复杂的截面形状,较高的形位、尺寸精度,以及较差的加工工艺性,对加工设备的性能提出了更高的要求。如何提高复杂曲面异型轧辊的加工质量、加工效率,降低成本,已成为冶金机械领域中备受关注的难点和热点之一。本课题以异型轧辊数控专用车床设计开发中的关键技术为切入点,利用曲线拟合理论、机械运动学、动力学理论、优化方法及有限元方法等手段,较深入地研究了异型轧辊数控专用车床的进给系统的设计理论和关键技术。取得了以下主要创新性成果:1.对异型轧辊横截面外轮廓曲线进行了分析与拟合,给出了异型轧辊环状孔型曲线的解析式;依据孔型曲线的特性,提出了分段逼近的策略和逼近方法。2.提出了异型轧辊数控车床采用双径向进给系统,并对进给系统刀具的运动特性进行了分析,利用ADAMS软件对刀具的径向进给运动进行了仿真,确定了刀具径向进给参数。3.完成了进给系统与主轴系统的运动学匹配设计。并得出两点结论:一是在满足加工精度的前提下,应尽可能地降低主轴转速,使径向进给速度和加速度具有较大设计空间;二是刀具的进给速度和加速度较高时,径向进给系统必须具有较高的刚度、固有频率和合适的阻尼,且具有较小的运动惯量、时间常数和弹性变形。4.建立了进给系统的结构模型和动力学模型。进行了动态性能仿真,并具体分析了传动系统各结构参数对系统动态性能的影响,优化了相关结构参数,满足了实际生产的要求。本课题是针对异型轧辊的加工提出的,其研究成果对非圆类零件车削加工技术的研究同样具有参考价值和指导意义。更多还原

【Abstract】 The roll is the most important part of the rolling mill and the most important deforming tool for the work piece. So the shape and the dimension accuracy of the roll are the most important elements for the machining quality of the work piece and can directly affect the rationality of manufacturing technique and economics of products. Non-circular cross-section rollers belong to the non-circular cross-section parts. Owing to their unique complexity of the outer surface contours, high request for precision of size and poor mechanical processing techniques, they have putted forward the very high request towards the dynamic properties of feed system on the CNC machine tool. So how to manufacture non-circular cross-section rollers efficiently and accurately has become one of the hot and knotty issues in the research of mechanical processing about non-circular cross-section parts.Based on the reality of poor processing precision and low processing efficiency of non-circular cross-section parts with the ordinary processing methods, the main task of this paper is to improve the dynamic properties of feed system on the CNC lathe by optimizing its related structure parameters. If this goal can be met by making an in-depth study, the feed system on the CNC lathe will satisfy requirements of production on quick response, high-precision and non-circular cross-section roller varied can be manufactured efficiently and accurately by turning . The main research contents are as follows.1. The data of the outer surface contours of noncircular cross section roller is analyzed and the curve fitting of cross-sectional outlines is obtained. According to the characteristics of the outer surface contours, the method to approximate the contours curve is proposed.2. Double feed systems along the radius are proposed and the motion characteristics of the tool during manufacturing are analyzed concretely in theory at first. Then by the aid of ADAMS which is used for dynamic analysis, the values of the feed parameters of the tool in processing are solved.3. The kinematics matching design of the feed system and the principal axis system is finished and two conclusions are obtained. First, on the condition of satisfying the machining precision, the rotational velocity of the principal axis should be cut down to enlarge the design space of the feed velocity and acceleration. Secondly, when the feed velocity and acceleration get a higher level, the radial feed system should possesses higher stiffness, higher inherent frequency, appropriate damp, lower inertia, minor time constant and minor flexibility deformation.4. The structure model and the dynamics model are built. The dynamic properties of feed system are simulated and analyzed. In addition, the impact on the dynamic properties which structure parameters of the feed system bring is analyzed concretely. The optimization objective functions are carried out and the simulation in relation to the optimization result are given. Simulation results indicate that the dynamic and static performance of the optimized feed system is superior to that of the original form and can meet the demand of production.In sum, the research results of this article are not only applicable to the production of non-circular cross-section rollers, but hold true for the production of all non-circular cross-section parts. So the research results of this paper have certain reference significance and practical utility towards the production of non-circular cross-section parts.更多还原