前平后球状桥壳管件充液压制成形的研究

发布时间：2018-03-11 13:37

本文选题：汽车桥壳　切入点：预成形管坯　出处：《燕山大学》2016年硕士论文　论文类型：学位论文

【摘要】：胀压成形工艺是一种新的桥壳制造方法,首先将初始管坯两端缩径和中部胀形得到一定形状的预成形管坯,再经充液压制成形为带有附加前盖的桥壳管件。胀压成形桥壳具有无焊缝、质量轻、强度刚度好等优点,目前工艺中附加前盖为球冠状,材料利用率不够高,工序较多,制造成本较高,本文设计了前平后球状桥壳管件,并对充液压制成形进行了研究,以期提高材料利用率,减少工序,降低制造成本。对于前平后球状桥壳,分析了预成形管坯充液压制的典型横截面、纵截面的变形过程,揭示了金属的流动规律,指出了压制过程中可能存在前平面凹陷和后盖开裂的问题及其影响因素。针对某载重5t的胀压桥壳,设计了预成形管坯的形状,给出了桥包部分后盖半径R1与制件桥包后盖半径R0的关系,即R_1=K_1R_0,给出了前盖半径R_2与后盖半径R_1的关系,即R_2=K_2R_1,其中K_1和K_2分别定义为后盖系数和前盖系数。设计了不同K_1和K_2的预成形管坯,进行液压胀形数值模拟,基于成形时管坯是否开裂和是否褶皱,初步确定了后盖系数和前盖系数的取值范围。再对此范围内的预成形管坯进行充液压制模拟,根据成形时后盖是否开裂和前平面是否凹陷,进一步确定了后盖系数和前盖系数的合适取值范围。基于一个最优的预成形管坯形状,先制定出某载重5t前平后球状桥壳的胀压成形工艺流程,并对初始管坯进行缩径、液压胀形和充液压制的数值模拟,得出桥壳壁厚分布规律。通过建立以桥壳成形性、工序数、生产成本和性能为评价指标的评价模型,采用评分法对前后球状胀压成形桥壳和前平后球状胀压成形桥壳的两种工艺方案进行了初步评价。
[Abstract]:The bulging forming process is a new method for manufacturing the bridge shell. Firstly, the pre-formed tube billet with certain shape is obtained by reducing the diameters at both ends and forming the middle part of the initial tube billet. The bridge shell has the advantages of no weld seam, light weight, good strength and rigidity, etc. At present, the additional front cover is spherical shaped, the material utilization ratio is not high enough, and there are many working procedures. The manufacturing cost is high. In this paper, the pipe fittings of the front and back spherical bridge shell are designed, and the hydraulic shaping is studied in order to improve the material utilization ratio, reduce the working procedure and reduce the manufacturing cost. The deformation process of typical cross section and longitudinal section of pre-formed tube billet is analyzed, and the flow rule of metal is revealed. This paper points out the problems and influencing factors of front plane depression and back cover cracking in the process of pressing. The shape of preformed tube billet is designed for a 5 t bulging bridge shell with a load of 5 tons. The relation between the radius R1 of the back cover of the part of the bridge package and the radius R 0 of the back cover of the part of the bridge package is given, that is, the relation between the radius of the front cover and the radius of the back cover, R1, is given, that is, R1C / K1R0, the relation between the radius of the front cover and the radius of the rear cover, That is to say, R2K2R / S / 1, in which Kal _ 1 and K _ S _ 2 are defined as the back cover coefficient and the front cover coefficient, respectively. The pre-formed tube billets with different K _ S _ 1 and K _ 2 are designed for numerical simulation of hydraulic bulging, based on whether or not the tube billet is cracked and folded at the time of forming, The value range of the back cover coefficient and the front cover coefficient is preliminarily determined. The pre-formed tube billet in this range is then simulated by hydraulic filling, according to whether the back cover is cracked or not and whether the front plane is depressed or not. Based on an optimal shape of preformed tube billet, the expansion and compression forming process of a 5 t front and back spherical bridge shell with a load of 5 tons is first worked out, and the initial pipe blank is reduced in diameter, and the optimum value range of the back cover coefficient and the front cover coefficient is determined. Through the numerical simulation of hydraulic bulging and hydraulic filling, the distribution law of the wall thickness of the bridge shell is obtained. The evaluation model, which takes the formability of the bridge shell, the number of working procedures, the production cost and the performance of the bridge shell as the evaluation index, is established. In this paper, two kinds of technology schemes of bulbous bulge forming bridge shell and front and rear spherical expansion pressure forming bridge shell are preliminarily evaluated by using the scoring method.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U466

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