LAPPING some general info(螺纹折叠形成原理).doc

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1、LAPPING折叠Seefollowingpicturesasexamplesforlapping看下述折叠图片.NotOKNotOKLappinginthreadLapping螺纹折叠折叠NotOKNotOKLappinginthreadMaterialfoldsorcracksinthethreadprofileLappingundermicrosocopeaftergrinding在螺纹轮廓上有材料折叠及裂纹金相显微镜下剖开后的螺纹折叠Reasonsforlapping:折叠原因1.Pitchisn

2、otadjustedcorrectly=matchingbetweenmoving(long)andstationary(short)threadingdie(seepicture1)螺纹线未正确调整=动静搓丝板未匹配(见图片一)2.Tomuchpressureonboltwhenplacedbetweenthethreadingdies(atthebeginningofthethreadingstation).Whenthepressureontheboltbetweenthetwothreadingd

3、iesistoHIGH,theboltwillstarttoslipinsteadofrotate.Whentheboltbeginstoslipyouwillhavelapping.(threadingdiesarepositionedtoclosetoeachother)将工件置于两搓丝板间时压力过大(开始加工螺纹时).当压力过大时螺栓开始滑移而非旋转.当螺栓开始滑移时就产生了折叠.(两搓丝板间距离太近)3.1and2canalsobecausedifthereisvariationintheshan

4、kdiameterbetweendifferentlots/containerswiththesamepart=whentheboltisheadedinonemachineandrolledinaseparatedthreadroller.Itisbettertorollthreadinaboltmakersoyouarecertainthattheblankdiameterdoesnotvary.如果不同批的零件同一部分螺纹坯径不均匀也会引起序号1及2描述中所产生的折叠=尽可能在同一台设备上镦制并且在

5、一个单独的螺纹设备上加工.由一台设备加工成形(带螺纹)会更好些.这样会确保螺纹坯径不会有变差.4.Notenoughpressureontheboltwhenplacedbetweenthethreadingdies,whenthepressureontheboltbetweenthetwothreadingdiesistoLOWtheboltcanbeintroducedtofarbetweenthethreadingdies(threadingdiesarepositionedtofarfromeac

6、hother)加工螺纹时压力不足.其产生原因是两搓丝板距离过远时.5.Incorrectintroduction(tolateortoearly)becausetheintroductionfingerisnotcorrect(tolongortoshort,wrongprofile).不正确的引入(过迟或过早)是因为送料板过长,过短,错误的形状.6.Timingoftheintroductionfingerinrelationtothemovementofthethreadingdiesisnotcor

7、rect(tolateortoearly)送料时间与搓丝板的运动时间(过早过晚)不匹配.7.Theblankisconicalandthereforenotintroducedstraightbetweenthethreadingdies螺纹坯径是锥形时引起工件不能直接引入到搓丝板间.8.Theblankisnotstraightandthereforenotintroducedstraightbetweenthethreadingdies毛坯杆弯会引起工件不能直接引入到搓丝板间.Inspectionfo

8、rlapping折叠检测Forinspectionforlappingwetake3bolts,degreasethemandplacethemfor1minuteinHCL(acid)with16%concentrationandtempof80°C.Thenrinsewithwateranddrywithcompressedair.Checkthethreadoneachboltunderamicroscopeforlap