小型铸钢件多维振动铸造机理研究

发布时间：2019-01-16 07:09

【摘要】：随着汽车、铁道车辆制造业的进步和我国铸造行业准入条件的推行,对整车的安全、高速、低耗、低成本及良好的舒适性等性能提出了较高要求。同时铸钢件型腔的复杂程度、壁厚、工艺精度等需求在不断提高,给铸钢件铸造工艺生产带来较多的工艺和生产难题。本文以振动优化列车车钩缩松缩孔为主要研究目标,基于TRIZ和拓扑机构设计理论设计制作了一台多维振动铸造机;利用EDEM-FLUENT液固两相流耦合和基于相似准则的物理模拟实验,分别研究了多维振动物性参数对小型铸钢件车钩试样充型和缩松缩孔的影响。利用TRIZ对现有振动铸造机系统功能、物质-场及因果关系进行分析,理清其冲突、矛盾所在,根据拓扑结构理论在现有铸造机基础上提出一种振动物性参数独立可调的多维振动铸造机构。利用ADAMS分析该多维运动机构在不同工况下的运动性质,验证振动在X、Y、Z方向的运动独立性,证明此并联机构为完全解耦。借助EDEM-FLUENT固液两相流耦合模拟分析小型铸钢件列车车钩的试样合金液在不同振动维数、振幅、振频下对充型流动的影响,得出:在维数为XYZ、频率为30Hz、振幅为0.35mm的振动条件下,铸钢液在螺旋试样中的充型流动长度最佳。基于相似准则和正交设计方式对小型铸钢件车钩试样进行实验设计,通过物理模拟实验研究多维振动参数对其缩松缩孔的影响,得出最优振动参数为维数为XYZ、振频35Hz、振幅0.30mm;并通过对各振动参数对缩松缩孔影响极差大小分析得出振动频率影响最大,振动维数(自由度)次之,振动幅值影响相对较小。为进一步验证多维振动铸造技术对小型铸钢件缺陷的改善程度,以安徽鑫宏有限公司生产中某型号小型铸钢件列车车钩为研究对象。通过ProCAST分析车钩内部所存在的缩松缩孔缺陷问题,并对原浇注方案存在的补缩不足问题进行优化。并在优化工艺基础上对车钩铸件充型过程施加同EDEM-FLUENT耦合模拟得出最佳振动物性参数;并对凝固过程施加物理模拟得出的最优振动参数进行振动优化。通过理论、数值模拟和实验分析得出,小型铸钢件列车车钩在振动参数为XYZ维数、30Hz频率、0.35mm振幅下充型,在XYZ维数、35Hz频率、0.30mm振幅凝固铸件缺陷改善程度最佳。通过对试制车钩样件进行X射线无损检测,检测结果表明振动优化后的车钩铸件缩松缩孔缺陷明显减少,铸件品质得到很大提升,有效的为企业解决缩松缩孔缺陷问题。由理论、数值模拟和实验分析得出,小型铸钢件列车车钩在振动参数为XYZ维数、30Hz频率、0.35mm振幅下充型,在XYZ维数、35Hz频率、0.30mm振幅凝固铸件缺陷改善程度最佳。
[Abstract]:With the progress of automobile and railway vehicle manufacturing industry and the implementation of the entry conditions of foundry industry in China, the safety, high speed, low consumption, low cost and good comfort of the whole vehicle are required. At the same time, the complex degree of casting cavity, wall thickness, process precision and other requirements are increasing, which brings more problems to the casting process production of steel castings. In this paper, a multi-dimensional vibration casting machine is designed and manufactured based on TRIZ and topological mechanism design theory, taking the vibration optimization of train couplers as the main research goal. By using EDEM-FLUENT liquid-solid two-phase flow coupling and physical simulation experiments based on similarity criterion, the effects of multi-dimension vibration animal parameters on filling mold and shrinkage hole of coupler specimen for small steel castings were studied. This paper analyzes the function, material field and causality of the existing vibratory casting machine system by using TRIZ, and clarifies the conflict and contradiction. Based on the topological structure theory, a multi-dimensional vibrating casting mechanism with independent and adjustable vibrational animal parameters is proposed on the basis of the existing foundry machines. The kinematic properties of the multi-dimensional kinematic mechanism under different working conditions are analyzed by using ADAMS. The kinematic independence of the vibration in the direction of XFY Z is verified. It is proved that the parallel mechanism is completely decoupled. With the aid of EDEM-FLUENT solid-liquid two-phase flow coupling simulation, the effects of the sample alloy liquid on the filling flow of couplers of small steel castings under different vibration dimensions, amplitudes and frequencies are analyzed. It is concluded that the dimension is 30 Hz at XYZ, frequency. When the vibration amplitude is 0.35mm, the filling length of molten steel in helical specimen is the best. Based on the similarity criterion and orthogonal design method, the experimental design of couplers for small steel castings was carried out. The effects of multi-dimensional vibration parameters on shrinkage and shrinkage of couplers were studied by physical simulation experiments, and the optimum vibration parameters were obtained as the dimension of XYZ, vibration frequency 35 Hz. Amplitude 0.30mm; The results show that the vibration frequency is the most important, the vibration dimension (degree of freedom) is the second, and the vibration amplitude is relatively small. In order to further verify the improvement degree of multi-dimensional vibration casting technology to the defect of small steel castings, a model of small steel castings train couplers produced by Anhui Xinhong Co., Ltd was taken as the research object. The defect of shrinkage hole in coupler was analyzed by ProCAST, and the problem of feeding deficiency in the original pouring scheme was optimized. On the basis of the optimized technology, the optimal vibrational animal parameters are obtained by applying the coupling simulation with EDEM-FLUENT to the filling process of the coupler casting, and the optimum vibration parameters obtained by the physical simulation of the solidification process are optimized. Through theoretical, numerical simulation and experimental analysis, it is concluded that the parameters of small cast steel train couplers are XYZ dimension, 30Hz frequency, 0.35mm amplitude filling, and the improvement degree of defects in solidified castings with XYZ dimension, 35Hz frequency and 0.30mm amplitude is the best. By means of X-ray nondestructive testing of the coupler sample, the results show that the shrinkage hole defects of the coupler castings after vibration optimization are obviously reduced, and the casting quality is greatly improved, which effectively solves the problem of shrinkage hole defects for enterprises. By theoretical, numerical simulation and experimental analysis, it is concluded that the parameters of small steel casting train coupler are XYZ dimension, 30Hz frequency, 0.35mm amplitude filling, and the best improvement degree is in XYZ dimension, 35Hz frequency, 0.30mm amplitude solidification casting defect.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG260

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