铝锂合金非对称截面型材四轴滚弯工艺研究

发布时间：2018-01-08 15:14

本文关键词：铝锂合金非对称截面型材四轴滚弯工艺研究　出处：《南京航空航天大学》2016年硕士论文　论文类型：学位论文

【摘要】：非对称截面新型铝锂合金型材被广泛应用于我国自主研制的大型客机C919中后机身的重要桁架零件制造,这类零件需采用四轴滚弯的成形方法。由于这类铝锂合金型材的材料比强度高、截面非对称、轮廓变曲率,采用传统滚弯方法不仅难于加工出高质量的型材,而且加工效率低、废品率高。为了满足飞机的研制,急需进行相关工艺研究。为此,本文以2099-T83铝锂合金2形及2099-T3铝锂合金L形型材的四轴滚弯成形为例,开展了相关关键工艺技术的研究。通过2099-T3及2099-T83铝锂合金材料的成形性能试验研究,得到了两种材料的主要成形性能参数及本构方程,进行了2099-T3及2099-T83铝锂合金板料的弯曲试验及模拟,分析了板料厚度、材料类型、下压量对板料回弹后弯曲角的影响,为后续的工艺模拟分析提供依据。从力学角度分析了2形及L形型材的滚弯过程,分析了滚弯成形中可能产生的工艺问题。以MC4P431IAS新型数控滚弯机为对象,进行了两种型材的等曲率滚弯模拟。首先,分析了摩擦系数对2形及L形型材滚弯回弹的影响,得到在不影响型材送料的情况下,型材与滚轮之间摩擦越小越好。然后,讨论了2形型材与滚轮之间间隙、下滚轮与2形型材下表面之间竖直方向预留间隙、左右滚轮X方向移动量对2形型材滚弯斜弯曲的影响;研究了不同上下滚轮夹紧型材量对L形型材滚弯斜弯曲的影响。由此得到了两种型材的滚弯斜弯曲控制方法,确定了两种型材的最佳滚弯工艺参数。最后,基于最佳滚弯工艺参数,完成了两种型材在不同左右滚轮抬升量下的等曲率滚弯模拟,得到了两种型材的滚弯成形规律及回弹规律。根据两种型材的最佳滚弯工艺参数及滚弯成形规律,设计并制造了2形及L形型材滚弯成形的滚轮模具,采用分段等曲率滚弯方法进行了两种型材的变曲率滚弯模拟及工艺验证试验,试验与模拟结果一致性较好。对滚弯试验后两种变曲率型材的纵向轮廓度、斜弯曲程度及截面尺寸偏差进行了分析,结果表明试验后的两种变曲率型材均满足设计要求。本文研究获得如下成果:(1)提出了2形及L形型材的滚弯斜弯曲控制方法。(2)得出了两种型材的滚弯成形规律。(3)提出了分段等曲率滚弯方法来解决变曲率型材零件的加工方案。完成了2形及L形变曲率型材的试制,攻克了C919客机型材滚弯成形工艺难题。研究取得的成果已成功应用于C919客机型材滚弯成形的生产,提升了我国型材滚弯加工水平。
[Abstract]:The important parts of non symmetrical section truss model of aluminum lithium alloy material has been widely used in China's self-developed large passenger aircraft C919 in the rear fuselage manufacturing, this kind of parts required by the four axis roll bending forming method. Because this kind of lithium aluminium alloy profiles material with high specific strength, non symmetrical section, contour curvature, the the traditional method is not only difficult to roll out processing profiles of high quality, and low processing efficiency, high rejection rate. In order to meet the urgent need for the development of aircraft, research related technology. Therefore, this paper takes 2099-T83 aluminium lithium alloy 2 and 2099-T3 aluminum lithium alloy L section four axis roll bending as an example, to carry out research the related key technology. Through the experimental investigation on formability of materials 2099-T3 and 2099-T83 aluminum lithium alloy, the main forming performance parameters of two kinds of materials and the constitutive equation of lithium aluminium alloy plate 2099-T3 and 2099-T83 materials The bending test and the simulation, the thickness of the plate material type, material analysis, under the pressure of springback of bending angle, provide the basis for the subsequent analysis of the process simulation. From the point of view of mechanics analysis of the roll bending process 2 and L profiles, analysis of the roll bending process problems that may arise in forming MC4P431IAS. With the new CNC bending machine as the object, the two section curvature bending simulation. Firstly, analyzed the influence of friction coefficient on the 2 and L section bending springback, obtained without affecting the profile feeding condition, the friction between the roller and the smaller the better profile. Then, the gap between the 2 section and the roller, the lower roller and the 2 profile under the surface between the vertical roller clearance, about X moving in 2 profile bending effect of oblique bending; Study on different roller clamping profiles amount on L profile bending oblique bending The effects are obtained. Oblique bending roll bending control method of two kinds of profiles, the optimum roll bending process parameters of two kinds of profiles are determined. Finally, the optimum roll bending process parameters based on the completion of two kinds of profiles in the different uplift under the left wheel curvature bending simulation, the roll bending two profiles of the law and law of springback. According to the two section of the optimum roll bending process parameters and roll bending rules, the design and manufacture of mold shaped and L shaped roller 2 roll bending forming, using piecewise curvature bending methods are two kinds of variable curvature roll simulation and process verification test the results of simulation and test agree well. The rolling bending test after two kinds of variable curvature profiles of the longitudinal profile deviation, oblique bending degree and section size were analyzed, the results show that two kinds of variable curvature profile after the test and meet the design requirements of this research. The results were as follows: (1) put forward the control method of 2 roll skew bending shape and L section. (2) the roll forming law of two sections. (3) proposed roll bending method for piecewise curvature to solve variable curvature profile machining scheme. Completed the trial and 2 L deformation curvature profile, to capture the C919 aircraft profile roll bending process problem. The research results have been successfully applied to the production of roll bending forming of C919 aircraft, raised China's profile bending processing level.

【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V261

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