摘 要

在新世纪以来，汽车行业逐渐成为了各个工业发达的国家的支柱性产业，汽车性能的安全、节能和环保是汽车工业的发展方向；铝、镁等有色金属具有重量轻，又方便与其它材料一起制成强度很高的复合材料，对于减轻汽车的自重、提高安全性、节能降耗等具有显著效果。所以近年来，铝等轻质的金属在汽车上的应用比重越来越重要，各个国家都在就铝镁材料代替钢制零件进行大量研究。连杆作为发动机的重要部件，主要负责发动机的传动由于运动惯性力的存在，发动机的上述各项性能指标均受到连杆品质的严重影响。随着连杆质量增加，运动惯性力增加，导致发动机的摩擦损失功率增加，零部件的机械负荷增大，磨损加快，平衡和振动问题加剧。因此，连杆轻量化对发动机具有十分重大的意义。

本文主要研究2A14铝合金连杆的锻造工艺，设计了锻件图，计算了坯料体积，在UG NX10.0中对连杆零件和上下模进行了建模。然后利用有限元模拟软件deform对连杆锻造成形过程进行数值分析，通过金属流动规律分析、锻件应力分析、应变分析、锻件温度场分析和成形过程力能曲线分析，揭示了连杆成形过程中存在的问题和缺陷，针对缺陷对模具进行了优化和改进，最终确定了合理的模具形状和尺寸，得到的锻件也符合要求。

关键词：铝合金连杆；锻造工艺；开式模锻；数值模拟

Abstract

Since the new century, the automotive industry has gradually become the pillar industry in developed countries. Safety, energy saving and environmental protection of automotive performance are the development direction of automotive industry. Non-ferrous metals such as aluminium and magnesium have light weight and are convenient to make composite materials with high strength together with other materials, which have obvious effects on reducing the weight of automobiles, improving safety, saving energy and reducing consumption. Therefore, in recent years, the application of light metals such as aluminium in automobiles has become more and more important. Various countries are doing a lot of research on replacing steel parts with aluminium-magnesium materials. As an important part of the engine, connecting rod is mainly responsible for the transmission of the engine. Because of the existence of inertia force, the performance indicators of the engine are seriously affected by the quality of connecting rod.With the increase of connecting rod mass and motion inertia force, the friction loss power of engine increases, the mechanical load of parts increases, wear accelerates, and the problems of balance and vibration aggravate. Therefore, lightweight connecting rod is of great significance to the engine.

This paper mainly studies the forging process of 2A14 aluminum alloy connecting rod, designs the forging drawing, calculates the blank volume, and models the connecting rod parts and upper and lower dies in UG NX10.0. Then the numerical analysis of the forging process of connecting rod is carried out by using the finite element simulation software deform. Through the analysis of metal flow law, stress analysis, strain analysis, forging temperature field analysis and force-energy curve analysis of the forming process, the problems and defects in the forming process of connecting rod are revealed. The die is optimized and improved according to the defects, and the reasonable die is finally determined. The shape and size of the forgings also meet the requirements.

Key Words：Aluminum alloy connecting rod; Forging process; Open die forging; Numerical simulation

目 录

第1章 绪论 1

1.1研究背景 1

1.2国内外研究现状 2

1.3研究目的及意义 4

1.4研究内容与方法 4

第2章2A14铝合金连杆锻造工艺设计 5

2.1 2A14铝合金连杆零件图 5

2.2 锻件图设计 6

2.2.1 确定锻件公差和机械加工余量 6

2.2.2 分模面确定 7

2.2.3 飞边槽设计 7

2.2.4 设备吨位的确定 8

2.3 计算毛坯图 9

2.4 连杆锻造工艺方案 12

2.4.2 下料 12

2.4.3 辊锻制坯 13

2.4.4 模锻 13

2.4.5 切边 14

第3章 锻造过程建模与分析 14

3.1 锻造过程模拟与分析 14

3.1.1 模拟初始条件 15

3.1.2 金属成形规律及填充情况分析 15

3.1.3锻件温度场分析 17

3.1.4 力能曲线分析 18

3.1.5 应力应变分析 19

3.2 本章小结 21

第4章 锻造过程与模具改进 22

4.1 型腔填充效果的改进 22

4.1.1 飞边槽的重新设计 22

4.1.2填充效果截面图 23

4.1.3 填充效果比较总结 24

4.2 模具磨损改善 25

4.2.1模具改进方案 25

4.2.2 改进后锻件应力分析 25

4.3 本章总结 27

第5章 结论 28

参考文献 29

致谢 31