目录
前言 ........................................................................................................................... 1 1 冷挤压基础知识 ................................................................................................. 2 1.1 冷挤压的实质及方法分类 ·························································· 2 1.2 冷挤压工艺的优缺点及应用范围 ················································· 2 1.2.1 冷挤压的特点 ······································································ 2 1.2.2 冷挤压的优点 ······································································ 3 1.2.3 冷挤压的缺点 ······································································ 4 1.2.4 冷挤压工艺的应用范围 ·························································· 4 1.3 冷挤压技术现状及发展方向 ······················································· 5 1.3.1 冷挤压技术的现状 ································································ 5 1.3.2 冷挤压技术发展方向 ····························································· 6 1.4 冷挤压模具设计基础知识 ·························································· 6 1.4.1 冷挤压模具的构造及特点 ······················································· 6 1.4.2 模具设计基本要求 ································································ 7 1.4.3 模具设计的一般程序 ····························································· 7 1.5 本文研究的主要内容 ································································ 8 2 冷挤压件图的设计及毛坯准备 ....................................................................... 10 2.1 冷挤压件图的设计 ································································· 10 2.2 毛坯的制备及处理 ································································· 12 2.2.1 坯料形状和尺寸确定 ··························································· 12
2.2.2 坯料的软化处理 ································································· 12 2.2.3 坯料表面处理及润滑 ··························································· 13 2.3 冷挤压工艺方案设计 ······························································ 14 2.4 冷挤压模具材料 ···································································· 15 3 挤压力的估算及挤压设备的选择 ................................................................... 16 3.1 影响单位挤压力的主要因素 ····················································· 16 3.2 冷挤压力的估算及压力机选择 ·················································· 18 4 模具结构设计 ................................................................................................... 19 4.1 凹模设计 ············································································· 19 4.1.1 凹模的结构形状设计 ··························································· 20 4.1.2 凹模各部分尺寸的设计计算 ·················································· 20 4.2 上模部分结构设计 ································································· 23 4.3 导向装置 ············································································· 24 4.4 卸料装置 ············································································· 25 4.5 凹模压板紧固螺钉计算 ··························································· 26 4.6 模具总体结构 ······································································· 26 5 凸、凹模失效形式及分析 ............................................................................... 28 5.1 凸模失效形式及分析 ······························································ 28 5.1.1 凸模失效原因 ···································································· 28 5.1.2 凸模失效形式 ···································································· 28 5.2 凹模失效形式及分析 ······························································ 31 5.3 齿轮部分冷挤压的相关问题 ····················································· 32
6 技术经济分析 ................................................................................................... 34 7 结论 ..................................................................................................................... 36 致谢 ......................................................................................................................... 37 参考文献 ................................................................................................................. 38 附录A ..................................................................................................................... 39 附录B译文 ............................................................................................................ 40 附录C外文资料 .................................................................................................... 51
前言
随着家用电器产量的迅速猛增，对锻压行业的工艺技术水平提出了更高的要求，突出的问题就是以少无切屑毛坯为核心的合理选择变形方式，提高材料利用率和制件尺寸精度、减少机械加工工时、降低能耗、提高生产率。为此，必需逐步研制和推广应用一项先进的金属塑性成形技术——冷挤压工艺。
对于汽车齿轮轴零件，过去一直采用切削加工方法得到，其生产工艺较为复杂，成本较高，效率较低，质量也不易保证。当采用冷挤压成形工艺后，该件制造工艺简单，生产效率能提高20倍以上，并且实现了少废料加工，节约了原材料，制件质量也得到了明显改进。
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