拖拉机用垫片的成型工艺与模具设计.doc

课程设计说明书
题目: 拖拉机用垫片的成型工艺与
模具设计
课程: 冲压工艺及模具设计
院(部): 机电工程学院
专业: 机械工程及自动化
班级:
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指导教师:
完成日期:
目录
摘要···································································3
1 零件的工艺性分析·····················································3
2 确定工艺方案·························································3
3 工艺计算
计算工艺力···························································· 4
·····················································5
材料利用率···························································· 6
4 压力中心确定,压力机选择
压力中心确定························································· 6
压力机选择···························································
7
5模具设计
确定模具结构························································· 6
模具零件尺寸计算与确定················································ 6
6 模具其他零件的选用
······················································· 6
选择上下模板及模柄···················································· 6
垫板凸模固定板························································ 6
闭合高度····························································· 6
导柱、导套····························································· 6
卸料螺钉····························································· 6
7 参考资料·····························································
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摘要
冲压是在室温下,利用安装在压力机上的模具对材料施加压力,使其产生分离或塑性变形,从而获得所需零件的一种压力加工方法。冲压模具在冷冲压加工中,将材料(金属或非金属)加工成零件(或半成品)的一种特殊工艺装备,称为冷冲压模具(俗称冷冲模)。冲压模具是冲压生产必不可少的工艺装备,是技术密集型产品。冲压件的质量、生产效率以及生产成本等,与模具设计和制造有直接关系。模具设计与制造技术水平的高低,是衡量一个国家产品制造水平高低的重要标志之一,在很大程度上决定着产品的质量、效益和新产品的开发能力。
1 零件的工艺性分析
该零件是拖拉机用的垫片,要对零件进行大批量的生产。该件属于隐蔽件,被完全遮蔽,外观上要求不高,只需平整,中心圆孔是该零件需要保证的重点。
2 确定工艺方案
首先根据零件的形状确定冲压工序类型和选择工序顺序。冲压该零件需要的基本工序有落料、冲孔。
方案一:先落料,再冲孔,采用单工序模生产。
方案二:落料和冲孔复合冲压,采用复合模生产。
方案三:冲孔落料连续冲压,采用级进模生产。
方案一模具结构简单,但需要两道工序、两套模具才能完成零件的加工,生产效率较低,难以满足零件大批量生产的需求。由于零件结构简单,为提高生产效率,主要应采用复合冲裁或級进冲裁方式。
复合模能在压力机一次行程内,完成落料、冲孔等多道工序,所冲压的工件精度较高,不受送料误差影响,内外形相对位置重复性好,表面较为平直。为了便于操作,所以复合模结构采用倒装复