闭式楔横轧成形轴端关键技术研究

发布时间：2018-06-11 09:51

本文选题：闭式楔横轧 + 滚子挡板　；参考：《宁波大学》2017年硕士论文

【摘要】：随着铁路和汽车行业对轴类件的需求日渐增大,对轴件材料利用率、产品质量与性能要求也愈来愈高。目前,楔横轧因具有高效节能节材优点而广泛应用于轴类件的成形,然而在楔横轧过程中出现端部凹心而需置料头,导致材料利用率最高达到85%而难以再提高,成为其工艺发展的瓶颈。由此,本文提出了闭式楔横轧成形轴端新工艺,用于解决端部凹心问题。本文采用了从后往前的研究顺序,先对具有轴端的轴件进行开式轧制,通过Deform-3D有限元软件分析轧制轴端成形过程中应力场、应变场、及轧制力、轧制力矩的变化,阐明轴端成形过程金属流动规律及工艺参数对力能参数的影响规律,同时对轴端长度、台阶长度、台阶倾角、断面收缩率等主要影响因素进行了交互试验,得到了各工艺参数对轴件端部质量的影响主次,通过回归得到了轴端长度和工艺参数的理论关系,最后进行了相应轧制实验验证,实验结果与模拟结果基本一致。在此基础上进行了闭式成形具有轴端的轴件研究,根据闭式楔横轧成形轴件机理,设计了变挡楔角挡楔作用轴端端部,避免了端部金属被挤进心部造成疏松,并对整个闭式轧制过程进行了应力场、应变场的分析,阐明了闭式轧制成形轴端的金属流动规律。针对闭式轧制时存在的轴向凸起问题,本文在挡板设计上进行了创新,把矩形挡板改成了为了更加准确成形轴件外圆面的滚子挡板,有效地解决了轧件轴向凸起。最后在提高轴件轴端质量问题上提出了“平端-闭开联合轧制”与“异形端-闭开联合轧制”两种新方法,对“异形端-闭开联合轧制”成形机理进行了研究,并进行了相应的轧制实验,进一步验证了该方法的可行性。本文的研究成果为解决轴件端部凹心提供了可靠的理论依据,丰富了可轧轴件的多样性,提高了轧件的材料利用率,为实际生产提供了理论指导。
[Abstract]:With the increasing demand for axle parts in railway and automobile industries, the requirements for material utilization, product quality and performance of axle parts are becoming higher and higher. At present, cross wedge rolling is widely used in the forming of shaft parts because of its advantages of high efficiency, energy saving and saving material. However, in the process of cross wedge rolling, because of the concave end part, the material utilization ratio is up to 85% and it is difficult to improve further. It becomes the bottleneck of technological development. Therefore, a new process of closed cross wedge rolling is proposed to solve the problem of end concave. In this paper, the research sequence from backward to forward is used to carry out open rolling of shaft parts with axial end. The stress field, strain field, rolling force and rolling moment are analyzed by Deform-3D finite element software. The law of metal flow and the influence of process parameters on the force and energy parameters are expounded. At the same time, the main influencing factors, such as axial end length, step inclination, section shrinkage and so on, are tested. The influence of the process parameters on the quality of the shaft end is obtained. The theoretical relationship between the length of the shaft and the process parameters is obtained by regression. Finally, the corresponding rolling experiments are carried out, and the experimental results are in good agreement with the simulation results. On the basis of this, the research of closed forming shaft with axial end is carried out. According to the mechanism of closed wedge cross rolling, the end part of shaft with variable wedge angle is designed to avoid the looseness caused by the end metal being squeezed into the center. The stress field and strain field of the whole closed rolling process are analyzed, and the metal flow law at the axial end of the closed rolling forming is explained. Aiming at the problem of axial bulge in closed rolling, the design of baffle is innovated in this paper. The rectangular baffle is changed into roller baffle for forming the outer circle surface of shaft more accurately, which effectively solves the axial protruding of rolling piece. Finally, two new methods of "flat end-close joint rolling" and "special end-close joint rolling" are put forward to improve the quality of shaft end, and the forming mechanism of "special end-close joint rolling" is studied. The feasibility of the method is further verified by corresponding rolling experiments. The research results in this paper provide a reliable theoretical basis for solving the end concave of shaft parts, enrich the diversity of rolling shaft parts, improve the material utilization ratio of rolled pieces, and provide theoretical guidance for practical production.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG335.19

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