【作者】 张金；

【导师】 华林；

【作者基本信息】 武汉理工大学 ， 材料加工工程， 2008， 硕士

【摘要】 环件冷轧是在常温下进行的连续局部塑性回转成形工艺,它具有省力、节能、节材、生产率高、生产成本低、产品质量好等显著优点,是各类小型轴承套圈、齿圈及其它精密环件制造的新工艺。环件冷轧的成形精度很高,这就要求作为其核心设备的冷轧环机具有相应的高精度,所以轧制的稳定性就是轧环机设计的核心问题之一。轧环机除了需要具有良好的运动学特性外,还要具备良好的环件加工的动力学特性。然而,目前轧环机工作参数的设计缺乏精确的理论指导,本文从冷轧环机的系统动力学角度出发,对冷轧设备进行理论及仿真分析,揭示设备动态性能的影响因素及其作用规律。在分析了冷轧环机的具体结构的基础上,按照数控机床的基本组成将冷轧环机按系统进行了分类,简述了理论建模所要考虑的主要参数,给出了相应的简化假设条件,在此基础上建立了D56G90型冷轧环机伺服进给系统的动力学模型。运用MATLAB软件建立了进给系统的仿真模型,对其动态性能进行了仿真分析,从机械动力学角度分别对进给系统的快、稳、准等性能进行了研究,分析了动态性能的影响因素,建立了环件轧制振动试验系统的架构,用以研究敏感因素的影响规律,并初步进行了不同进给速度下的振动试验,采集了时域信号,对其作用规律做了相关的分析,验证了试验架构的可行性。建立了进给系统轴向刚度及扭转刚度的力学模型,分析了压缩刚度和扭转刚度对冷轧环机进给系统进给误差的影响,导出的冷轧环机进给系统综合刚度的解析表达式,实现了进给系统刚度的定量分析,并通过ANSYS仿真分析验证了上述模型及理论推导的正确性,为进给系统的设计和改进提供了理论依据。分析了驱动辊系统的主要结构,建立了其关键部件主轴—轴承的动力学仿真模型,其中添加了轴承的弹性特征,分析得到了主轴部件的固有频率和振型,总结了轴承预紧力的变化对轴承刚度和主轴部件固有频率的影响规律,为设备的抗振性分析奠定了基础。更多还原

【Abstract】 Cold ring rolling is a high efficient rolling method for manufacturing such as seamless bearing rings, gear rings and other precise rings, which use the craft of continuous partial plastic deformation at room temperature. Cold ring rolling is of many characteristics such as energy saving and production cost, increasing utilization ratio of energy and material, rising productivity, widening processing range of ring products etc.The products of cold rolling ring have high accuracy, accordingly, the cold ring rolling mill as the core equipment should be precise. So the stability of rolling is to be one of the key problems to designing. The cold ring rolling mill should not only have satisfied kinematical performance, but also good dynamic drive and control performance. However, there is lake of accurate theoretical criterions for cold ring rolling mill design. Thus, this paper was proceeded theoretical analysis and simulation on characteristics of rolling equipment’s dynamics and obtained the typical influence parameters which act on dynamic performances of cold ring rolling and expounded the law of how they act.According to the fundamentals of NC machine, classified the different system of cold ring rolling mill after analyzing its structure. Described the key parameters of academic molding and given the simplified suppose of dynamic model. On that basis, an equivalent dynamic model of the mechanical transmission structure of D56G90 cold ring rolling mill was built.The paper used MATLAB to simulate the dynamic performance of its mechanical transmission system. Analyzed the rapidity、stability and accuracy of feed system from the angle of mechanical kinetics.Then, expounded the key influencing factors of dynamic performance. Finally, carried out a libration test with different feed speed, gathered time-domain signal and analysed its operating laws, which certificated the feasibility of the test frame.The mechanical model of axial rigidity and torsional rigidity were established. Then, the effect of compress rigidity and torsional rigidity on feed error of feed system of cold ring rolling mill was analyzed. The analytical express of composite rigidity of servo feed system could make it possible to quantificationally analyze its rigidity, and verified the correctness of model through the ANSYS simulation, which pointed out the direction of design and improvement of servo feed system.Described the main structure of driven roll system and established the simulating model of the key part of spindle which added elastic element of bearing. In the paper, obtained the low-order natural frequency and mode of spindle through simulation and generalized the influencing laws about how bearing pretightening force act on the natural frequency and mode of spindle, which laid the foundation of vibration resistance analysis.更多还原