冲压零件常见缺陷

1、李志辉1Stamping parts Common defects anaylse李志辉2模具开发基本流程 Dies project flow 产品设计Body design冲压工艺设计Stamping Process 模具结构设计Die design铸造FMC&Casting加工/装配Machining/AssemblingCAE同步分析SE work调试TryoutCAE同步分析SE workDL图设计Die layout design量产quantity production李志辉产品数模生产纲领参考工艺技术标准设备参数零件工艺性分析CAE拉延修冲CAM.翻边工艺制订CAE冲压方

2、向内容分配模具结构分模线.冲压工艺基本流程 Die Process flow3李志辉4零件常见问题 Common defects零件成形时常见问题：零件成形时常见问题：Common defects of stamping parts 起皱 Wrinkle 开裂 Crack 回弹 Springback 表面质量（塌陷、滑移线、冲击线） Surface quality( dent, slip line, skid line)李志辉5起皱 Wrinkle李志辉6主要原因：由于板料受到挤压，当平面方向的主、次应力达到一定程度时，厚度方向失稳，从而产生起皱现象。Main reason: The blan

3、k have been extrusion, the Major strain ,minor strain go to worst, Thickness direction of instability, bring wrinkle.材料堆集起皱。进入凹模腔内材料过多变成的皱纹。 Material gathered. The material enter dies too more caused the wrinkle失稳起皱 Instability A.板料厚度方向增厚失稳。 Thickness direction less sanction force, increasation. B.拉

4、伸应力不均匀而产生的皱纹。（例如：门把手区域） Strain asymmetrical (For example: Door handle area)起皱原因 Reason of wrinkle李志辉7 产品设计 Product design： A、降低翻边高度或整形深度；Decrease the depth of flange or restrike, B、将造型剧变区域接顺；Smooth the upheaval area, C、产品起皱部位增加吸料造型。Add shape of the suction. 冲压工艺 Process： A、提高压料力，调整拉延筋； Add the press

5、ure of binder, adjust the draw bead, B、工艺补充增加吸皱造型； Add shape of the suction in addendum C、检查拉延毛坯、局部材料流动情况的合理性，调整压料面 Check material enter speed, adjust the binder. D、增加成形工序 Add restrike operation 材料 Material： 在满足产品性能的情况下，选用成形性较好的材料 Choose best material if can meet the requirment 起皱解决办法 Solution of wr

6、inkle李志辉8零件开裂问题 Crack李志辉9开裂原因 Reason of crack主要原因：由于材料在拉伸过程中，应变超过其极限，而形成失稳。Main reason: Material extend over the limit strain 材料抗拉强度不足而产生的破裂，如靠凸、凹模R角处，局部受力过大而破裂。 Over the limit strain, for example: crack near edge R of punch and dies.材料变形量不足而破裂，尖点部位的开裂。 Lack of strain, for example: crack at tine条纹状裂

7、纹，由于材料内有杂质引起的裂纹，一般平行于板料扎制方向。 Striation crack, bad material which have impurity, usually parallel the coil direction. 李志辉10 材料方面：采用拉延性能较好的材料 Material: use better ductility material. 减少应变方面：Decrease the strain.A、选择合理的坯料尺寸和形状 Choose the best size & shape of blankB、调整拉延筋大小 Change the size of draw be

8、ad C、增加辅助工艺（切口等） Add arts and crafts (cut in draw, etc.)D、改善润滑条件 ( improve smoothly )E、修改工艺补充面( modify the die face )F、调整压料力( change the force of binder)G、.开裂解决办法 Solution of crack李志辉11回弹问题 Spring back回弹 Spring back：零件在冲压成形后，材料由于弹性卸载，导致局部或整体发生变形。 After form, uninstall the stress, parts deformed应力李志辉

9、12影响回弹的因素很多，实际生产中很难解决。The causation of spring back is too more, solve it difficult.目前，解决回弹常用下面几种方法：Solution of spring back: 补偿法 Compensation。其原理是根据弯曲成形后板料的回弹量的大小预先在模具上作出等于工件回弹量的斜度，来补偿工件成形后的回弹（经验和CAE模拟）；The principle is to make the slope is equal to the workpiece springback on the mold in advance dep

10、ending on the size of the sheet after springback in bending and forming, to compensate for springback in the workpiece after forming (experience and CAE simulation);2、拉弯法 Tension 。是在板料弯曲的同时施加拉力来改变板料内部的应力状态和分布情况，使应力分布较为均匀，减少回弹量；Change the stress within the distribution, so that the stress more evenly

11、 distributed, reducing the amount of spring back;3、采用成形性较好的材料。Use better material.回弹解决办法 Solution of spring back李志辉13表面质量问题 Surface quality defects 李志辉14表面质量问题产生原因 Reason of surface quality defects主要类型：Sort: 冲击线、滑移线、塌陷、暗坑、表面扭曲等Skid line, slip line, dent, twist, etc.对于外板零件来说，外表面产生的缺陷是不接受的。Surface qua

12、lity is not acceptant to outer partss class A surface冲击线、滑移线主要是由于在冲压过程中，板料和模具接触后，在应力集中处摩擦造成的表面划痕。 Skid line, slip line is the blank touch the die R, nicked by stress concentration塌陷、暗坑、表面扭曲主要是由于零件变形不充分，局部材料应变较小，外力释放后出现的缺陷。 dent, twist caused by strain not enough, some area strain is less, defects ap

13、peared when the tension release李志辉15 消除滑移线，可以通过改变产品形状（左右对称，增大圆角R值）、增大阻力减少滑动量等方式。 Avoid slip line , can modify the shape of product( symmetry, increase R), increase force to decrease the slide, etc. 消除冲击线，可以通过改变冲压圆角、凹模圆角，增加拉延深度，更改压料面等方法。 Avoid skid line, can modify the R, increase the depth of draw,

14、modify the die face. 消除塌陷、表面扭曲，应了解零件在变形区所产生应力梯度的等级，尽量保证产品塑性变形的均匀性。同时通过增大阻力，提高局部形状应变等手段。 Avoid dent, twist, need analyze the strain in this area, ensure it is equality. Increase the force, increase strain, etc. 表面质量问题解决办法Solution of surface quality defects李志辉16Cases anaylse李志辉一、冲压负角（1）Undercut(1)AA缺陷

15、：缺陷：在冲压方向有负角，如采用侧整形工艺，增加大量模具成本。Risk: Undercut in press direction, Use CAM-Rst will increase the cost of Die措施：措施：保证拔模角度3以上。optimization: Ensure the draft angle above 3.SECTION A-Amin3Press direction冲压方向Press direction冲压方向李志辉一、冲压负角（2）Undercut(2)缺陷：缺陷：在冲压方向有负角，无法拉延成形。Risk: Undercut in press direction.

16、措施：措施：加大拔模角度，保证无负角。Optimization: Increase the draft angle, ensure none undercut李志辉一、冲压负角（3）Undercut(3)缺陷：缺陷：在冲压方向有负角，无法成形。.Risk: Undercut in press direction.措施：措施：将和两特征连接起来，消除冲压负角。Optimization: Unite & , Cancel the under cutPress direction冲压方向Press direction冲压方向 李志辉二、开裂（1）Crack(1)缺陷：缺陷：门把手局部形状太深

17、，存在开裂风险。Risk: The height of Handle too deep, have crack here. 措施：措施：降低深度并增大R角，。Optimization: Decrease the depth, and increase the R.AASECTION A-A李志辉二、开裂（2）Crack(2)缺陷：缺陷：产品R角处翻边高度过大，存在开裂风险。Risk: The Flange length on the corner is too long, have risk of crack.措施：措施：降低拐角处翻边高度至35mm。Optimization: Decreas

18、e the length of Flange to 3 5 mm李志辉二、开裂（3）Crack(3)缺陷：缺陷：凸包特征变化急剧，拉延开裂。Risk: The diversification of table is sudden, crack in drawing.措施：措施：更改局部特征平滑过渡，增大R角。Optimization: Change the table diversification smoothly, Increase the R.李志辉三、起皱（1）Wrinkle(1)缺陷：缺陷：此区域整形时，由于整形刀与各面未同时接触，导致a处存在波纹(A面表面质量问题）。Risk: T

19、he steel for flange touch the die face not the same time, cause the wrinkle in the face a (Class A face)措施：措施：增加一个与表面平行的台阶。Optimization: Add a table which the same height to Class A face.aa李志辉三、起皱（2）Wrinkle(2)缺陷：缺陷：产品R角处翻边高度过大，存在叠料现象。Risk: The flange length on the corner is too long, will wrinkle he

20、re.措施：措施：减小R角部位翻边高度，保证翻边高度3mm5mm。Optimization: Decrease the flange length on the corner, ensure 3mm5mm. 李志辉三、起皱（3）Wrinkle(3)缺陷：缺陷：翻边时拐角处叠料。Risk: The flange on the corner will wrinkle.措施：措施：降低局部翻边高度，按红色线修改零件轮廓。Optimization: Decrease the flange length, like the red line.5mm5mm李志辉三、起皱（4）Wrinkle(4)缺陷：缺陷

21、：成形过程中坯料流动不均匀，引起表面起皱。Risk: The material inrush asymmetry, cause wrinkle in the Class A face. 措施：措施：改变图示位置产品结构形状（局部加凹槽或形状平缓过渡）。Optimization: Change the table shape, like the picture.李志辉三、起皱（5）Wrinkle(5)缺陷：缺陷：由于形状特征限制，门内板此处起皱现象十分典型。Risk: There is a typical wrinkle in door inner措施：措施：局部增加深凹槽吸皱。Optimiza

22、tion: Add the groove 李志辉四、回弹（1）Spring back(1)缺陷：缺陷：此类弧形长条状零件,造型相对简单,通常易发生扭曲、回弹现象，需长时间调试，难度高。Risk: Parts like this, Spring back because the shape simple, Usually contort self, difficult solve it, spend more time.措施：措施：适当增加条槽型加强筋，利于回弹控制，缩短模具开发时间。Optimization: Add the rib, decrease spring back, save th

23、e time of tryout李志辉四、回弹（2）Spring back(2)缺陷：缺陷：U形件回弹不易控制。Risk: The spring back difficult to control with the U figure parts. 措施：措施：加强凹方形筋控制反弹。Optimization: Add the rib李志辉缺陷：缺陷：修边困难。Risk: Difficult to trim 措施：措施：规则补齐产品轮廓，确保刃口强度Optimization: Change the edge regular, ensure the strength of steel cut. 五、

24、修冲困难（1）Trim risk(1)）李志辉五、修冲困难（1.1）Trim risk(1.1)李志辉缺陷：缺陷：修边轮廓距R太近，压料器强度弱，修边条件差。Risk: The trim line near the R, less strength of PAD. 措施：措施：保证法兰边宽度 5mm。Optimization: Ensure the length over 5mm5mm五、修冲困难（2）Trim risk(2)李志辉缺陷：缺陷：孔距边太近，凸模强度差，修边困难。Risk: The hole near the wall, less strength of punch.措施：措施：

25、修改产品轮廓，保证孔边缘距R角距离 5mm。Optimization: Modify the edge of hole, ensure over 5mm distanceMin.5mmMin.5mm五、修冲困难（3）Trim risk(3)李志辉缺陷：缺陷：豁口太小，冲切时刀块刃口强度差，影响模具使用寿命。Risk: the distance of it is little , less strength of steel, effect the life time.措施：措施：修改产品轮廓，增大豁口宽度 5mm。Optimization: Modify the trim line, add the distance of it over 5mm五、修冲困难（4）Trim risk(4)李志辉缺陷：缺陷：零件此处局部形状无法正修边，如采用侧修边工艺，将增加模具开发及维护成本。Risk: Cant direct trim here, Use CAM trim will add the cost.措施：措施：修改产品轮廓，R根部平直补出5mm。Optimization: Modify the trim line to the under face in order to direct trim possibile.五、修冲困难（5）Tr