冲压零件常见缺陷分析课件

#,1,冲压零件常见缺陷分析,Stamping parts Common defects anaylse,1冲压零件常见缺陷分析,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/,Assembling,CAE,同步分析,SE work,调试,Tryout,CAE,同步分析,SE work,DL,图设计,Die layout design,量产,quantity production,2模具开发基本流程 Dies project flow 产,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,冲压方向,内容分配,模具结构,分模线,.,冲压工艺基本流程,Die Process flow,3,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,4,零件常见问题,Common defects,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),4零件常见问题 Common defects零件成形时常见问,5,起皱,Wrinkle,5起皱 Wrinkle,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 blank 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,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,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 pressure 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 wrinkle,7产品设计 Product design：起皱解决办法 So,8,零件开裂问题,Crack,8零件开裂问题 Crack,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.,9开裂原因 Reason of crack主要原因：由于材料,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 blank,B,、调整拉延筋大小,Change the size of draw bead,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,10材料方面：采用拉延性能较好的材料开裂解决办法 Solut,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,11回弹问题 Spring back回弹 Spring ba,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 depending 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 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,12影响回弹的因素很多，实际生产中很难解决。回弹解决办法 S,13,表面质量问题,Surface,quality defects,13表面质量问题 Surface quality defe,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 quality 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 appeared when the tension release,14表面质量问题产生原因 主要类型：Sort:,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,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,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,16,案例分析,Cases anaylse,16案例分析,一、冲压负角（,1,）,Undercut(1),A,A,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：,保证拔模角度,3,以上。,optimization:Ensure the draft angle above 3.,SECTION A-A,min3,Press direction,冲压方向,Press direction,冲压方向,一、冲压负角（1）AA缺陷：在冲压方向有负角，如采用侧整形工,一、冲压负角（,2,）,Undercut(2),缺陷：,在冲压方向有负角，无法拉延成形。,Risk:Undercut in press direction.,措施：,加大拔模角度，保证无负角。,O