冲压零件常见缺陷分析

1,冲压零件常见缺陷分析StampingpartsCommondefectsanaylse,2,模具开发基本流程Diesprojectflow,产品设计Bodydesign,冲压工艺设计StampingProcess,模具结构设计Diedesign,铸造FMC2、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；Changethestresswithinthedistribution,sothatthestressmoreevenlydistributed,reducingtheamountofspringback;3、采用成形性较好的材料。Usebettermaterial.,回弹解决办法Solutionofspringback,13,表面质量问题Surfacequalitydefects,14,表面质量问题产生原因Reasonofsurfacequalitydefects,主要类型：Sort:冲击线、滑移线、塌陷、暗坑、表面扭曲等Skidline,slipline,dent,twist,etc.对于外板零件来说，外表面产生的缺陷是不接受的。SurfacequalityisnotacceptanttoouterpartssclassAsurface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。Skidline,sliplineistheblanktouchthedieR,nickedbystressconcentration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,twistcausedbystrainnotenough,someareastrainisless,defectsappearedwhenthetensionrelease,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。Avoidslipline,canmodifytheshapeofproduct(symmetry,increaseR),increaseforcetodecreasetheslide,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。Avoidskidline,canmodifytheR,increasethedepthofdraw,modifythedieface.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。Avoiddent,twist,needanalyzethestraininthisarea,ensureitisequality.Increasetheforce,increasestrain,etc.,表面质量问题解决办法Solutionofsurfacequalitydefects,16,案例分析Casesanaylse,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:Undercutinpressdirection,UseCAM-RstwillincreasethecostofDie,措施：保证拔模角度3以上。optimization:Ensurethedraftangleabove3.,SECTIONA-A,min3,一、冲压负角（2）Undercut(2),缺陷：在冲压方向有负角，无法拉延成形。Risk:Undercutinpressdirection.,措施：加大拔模角度，保证无负角。Optimization:Increasethedraftangle,ensurenoneundercut,一、冲压负角（3）Undercut(3),缺陷：在冲压方向有负角，无法成形。.Risk:Undercutinpressdirection.,措施：将和两特征连接起来，消除冲压负角。Optimization:Unite&,Canceltheundercut,二、开裂（1）Crack(1),缺陷：门把手局部形状太深，存在开裂风险。Risk:TheheightofHandletoodeep,havecrackhere.,措施：降低深度并增大R角，。Optimization:Decreasethedepth,andincreasetheR.,A,A,SECTIONA-A,二、开裂（2）Crack(2),缺陷：产品R角处翻边高度过大，存在开裂风险。Risk:TheFlangelengthonthecorneristoolong,haveriskofcrack.,措施：降低拐角处翻边高度至35mm。Optimization:DecreasethelengthofFlangeto35mm,二、开裂（3）Crack(3),缺陷：凸包特征变化急剧，拉延开裂。Risk:Thediversificationoftableissudden,crackindrawing.,措施：更改局部特征平滑过渡，增大R角。Optimization:Changethetablediversificationsmoothly,IncreasetheR.,三、起皱（1）Wrinkle(1),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:Thesteelforflangetouchthediefacenotthesametime,causethewrinkleinthefacea(ClassAface),措施：增加一个与表面平行的台阶。Optimization:AddatablewhichthesameheighttoClassAface.,a,a,三、起皱（2）Wrinkle(2),缺陷：产品R角处翻边高度过大，存在叠料现象。Risk:Theflangelengthonthecorneristoolong,willwrinklehere.,措施：减小R角部位翻边高度，保证翻边高度3mm5mm。Optimization:Decreasetheflangelengthonthecorner,ensure3mm5mm.,三、起皱（3）Wrinkle(3),缺陷：翻边时拐角处叠料。Risk:Theflangeonthecornerwillwrinkle.,措施：降低局部翻边高度，按红色线修改零件轮廓。Optimization:Decreasetheflangelength,liketheredline.,5mm,5mm,三、起皱（4）Wrinkle(4),缺陷：成形过程中坯料流动不均匀，引起表面起皱。Risk:Thematerialinrushasymmetry,causewrinkleintheClassAface.,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:Changethetableshape,likethepicture.,三、起皱（5）Wrinkle(5),缺陷：由于形状特征限制，门内板此处起皱现象十分典型。Risk:Thereisatypicalwrinkleindoorinner,措施：局部增加深凹槽吸皱。Optimization:Addthegroove,四、回弹（1）Springback(1),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:Partslikethis,Springbackbecausetheshapesimple,Usuallycontortself,difficultsolveit,spendmoretime.,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:Addtherib,decreasespringback,savethetimeoftryout,四、回弹（2）Springback(2),缺陷：U形件回弹不易控制。Risk:ThespringbackdifficulttocontrolwiththeUfigureparts.,措施：加强凹方形筋控制反弹。Optimization:Addtherib,缺陷：修边困难。Risk:Difficulttotrim,措施：规则补齐产品轮廓，确保刃口强度Optimization:Changetheedgeregular,ensurethestrengthofsteelcut.,五、修冲困难（1）Trimrisk(1)）,五、修冲困难（1.1）Trimrisk(1.1),缺陷：修边轮廓距R太近，压料器强度弱，修边条件差。Risk:ThetrimlineneartheR,lessstrengthofPAD.,措施：保证法兰边宽度5mm。Optimization:Ensurethelengthover5mm,5mm,五、修冲困难（2）Trimrisk(2),缺陷：孔距边太近，凸模强度差，修边困难。Risk:Theholenearthewall,lessstrengthofpunch.,措施：修改产品轮廓，保证孔边缘距R角距离5mm。Optimization:Modifytheedgeofhole,ensureover5mmdistance,Min.5mm,Min.5mm,五、修冲困难（3）Trimrisk(3),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:thedistanceofitislittle,lessstrengthofsteel,effectthelifetime.,措施：修改产品轮廓，增大豁口宽度5mm。Optimization:Modifythetrimline,addthedistanceofitover5mm,五、修冲困难（4）Trimrisk(4),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:Cantdirecttrimhere,UseCAMtrimwilladdthecost.,措施：修改产品轮廓，R根部平直补出5mm。Optimization:Modifythetrimlinetotheunderfaceinordertodirecttrimpossibile.,五、修冲困难（5）Trimrisk(5),缺陷：冲孔时，冲头与制件干涉。Risk:Haveinterferencebetweenthepunchandparts,措施：将孔的位置向上移动10mm，保证冲头与制件不干涉。Optimization:Movethehole,10mmensurenointerference.,SectionA-A,五、修冲困难（6）Trimrisk(6),缺陷：凸台上的孔距边太近，冲孔时下模强度差。Risk:Thedistanceofholetoedgeistoolittle,lessstrengthofpunch,措施：增大凸台形状或减小孔的尺寸，保证上图所示参数值。Optimization:Enlargethetableordecreasethesizeofhole.,五、修冲困难（7）Trimrisk(7),六、翻边质量差Worseflange,缺陷：翻边法兰直边宽度小，冲压成形后此翻边特征难保证。Risk:Lessflangelength,difficulttoform.,措施：增大翻边高度，保证过R直翻边宽度1.5