三辊Y型轧机关键技术研究

发布时间：2018-10-09 09:18

【摘要】：当前最具发展潜力的工程材料是镁合金,而镁合金材料的塑性加工技术中综合性能较好的为轧制工艺,但是镁合金棒材轧机优化设计还需要进一步的研究。实际轧制过程中,三辊Y型轧机存在异常振动、冷却效果低下、润滑油中渗水问题,将文章的重点放在轧机主传动系统扭振分析、冷却液与轧辊表面对流热换特性解析、轧机油水分离系统改进。主要研究工作为:1.根据机械动力学中相关扭振动力学基础理论,创建三辊Y型轧机主传动系统扭转振动的动力学模型;推导出扭振动力学方程,并计算出系统中每个组件等效惯量和等效刚度;在MATLAB中求解三辊Y型轧机主传动系统的固有频率以及每一阶固有频率所对应主振型,分析数据能够供设计人员进行结构设计以及扭振抑制;最后,分别从固有频率提高、振源削弱两方面进行轧机扭振抑制的分析。2.利用FLOTRANCFD软件进行冷却液与轧辊表面的流热耦合分析,对流热耦合分析中所涉及有限元理论、喷嘴射流特性、边界条件设置进行说明;通过设定不同的冷却液初始温度、喷嘴与轧辊表面的间距、冷却液的初始喷射速度、喷射角度以及自身粘度等参数对冷却液与轧辊表面进行有限元仿真分析,得到不同因素对于冷却液与轧辊表面对流热换系数的影响;通过正交试验对所有影响因素进行排序,根据所得结果提高轧辊表面的冷却效率。3.分别从轧机牌坊分布结构、轧机密封结构以及润滑油含水率监测三个方面进行轧机油水分离系统的改进。保证将冷却液与润滑油有效分离开来,并且冷却液和润滑油能够通过各自的循环系统重复使用,不仅改善了生产环境,还延长了轴承使用寿命,提高了轧制质量。将研究结果应用于镁合金棒材连轧工艺中,能够有效地避免实际轧制过程中的异常振动、冷却效率低下、润滑油与冷却液混合等问题,具有较高的工程指导意义。
[Abstract]:At present, magnesium alloy is the most promising engineering material, and the best comprehensive properties of magnesium alloy is rolling process. However, the optimization design of magnesium alloy bar mill needs further research. In the actual rolling process, there are abnormal vibration, low cooling effect and water seepage in lubricating oil in three-high Y type mill. The paper focuses on the torsional vibration analysis of the main transmission system of the mill and the analysis of convection heat transfer characteristics between the coolant and the surface of the roll. Improvement of oil and water separation system for rolling mill. The main research work is: 1. Based on the basic theory of torsional vibration dynamics in mechanical dynamics, the dynamic model of torsional vibration of main drive system of three-high Y mill is established, the dynamic equation of torsional vibration is derived, and the equivalent inertia and stiffness of each component in the system are calculated. In MATLAB, the natural frequency of the main drive system of the three-high Y type mill and the main mode corresponding to the natural frequency of each order are solved. The analysis data can be used for the structural design and torsional vibration suppression of the designer. Finally, the natural frequency is increased respectively. Analysis of torsional vibration suppression of rolling mill from two aspects of weakening vibration source. The fluid-heat coupling analysis between coolant and roll surface is carried out by using FLOTRANCFD software. The finite element theory, nozzle jet characteristics and boundary condition setting are described in the convection-heat coupling analysis, and the initial temperature of the coolant is set. The distance between the nozzle and the surface of the roll, the initial injection velocity of the coolant, the injection angle and the viscosity of the coolant were simulated by finite element method. The influence of different factors on the convection heat transfer coefficient between the coolant and the roll surface was obtained, and the cooling efficiency of the roll surface was improved by orthogonal test. The oil and water separation system of rolling mill was improved from three aspects: distribution structure of mill arch, seal structure of rolling mill and monitoring of water content of lubricating oil. It is ensured that the coolant and lubricating oil can be separated effectively, and that the coolant and lubricating oil can be reused through their respective circulation system, which not only improves the production environment, but also prolongs the bearing service life and improves the rolling quality. The application of the research results to the continuous rolling process of magnesium alloy bars can effectively avoid the abnormal vibration in the actual rolling process, the cooling efficiency is low, the lubricating oil and the coolant are mixed, and so on, which has higher engineering guiding significance.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG333

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