马头牌扭力扳手VIP专享VIP免费

TighteningTechnics&Tools基本的扭紧技术和工具Whatyouwilllearn我们将学到什么•Basisontighteningtechnics基本的扭紧技术•Tooltechnologies工具的扭紧技术•Howtoselecttherighttool如何选择扭紧工具2Introduction引子Tighteningofthreadedfastenersisfoundalmosteverywherethereisanindustrialactivity−frommaintenanceinchemicalprocessplants−tomanufactureoflaptopcomputers3Introduction引子Reasonsforusingscrewjoints使用螺栓连接的原因••••4Introduction引子SmallscrewsSelfdrilling,threadformingscrewsWoodscrewsScrewsforthreadcuttinginbrittleplasticsScrewswithdifferenttypesurfacetreatmentand,withdifferentmaterialqualityHOLDINGpartsinsidehouseholdappliancesSheetmetaldesigns,aluminumboxes,fixinglabels,etc.Furniture,woodindustryAssembliesinplastichousingsAppearanceandnottocausecorrosionFor:5Agenda内容•Basisontighteningtechnics基本的扭紧技术•Tooltechnologies工具的扭紧技术•Howtoselecttherighttool如何选择扭紧工具6Ajoint连接7•在工业领域大量采用•优于其它的连接方法Torquedefinition扭矩的定义8螺栓的夹紧力－螺栓张力张力张力夹紧力夹紧力CLAMPINGFORCE夹紧力Clampingforce夹紧力TENSION张力TORSION扭力TENSION张力=CLAMPINGFORCE夹紧力Objective目的CreateaCLAMPINGFORCE创建一个夹紧力Torsion扭力Tension张力Clampingforce夹紧力10张力与夹紧力：大小相等，方向相反！TENSION产生张力10%TORSION扭力100％THREADFRICTION螺纹摩擦力40%EffortsRepartition影响因素CLAMPINGFORCE夹紧力HEADFRICTION螺帽摩擦力50%只有10％的扭矩被用来产生了张力！TORQUE=TENSION+FRICTION100％＝10%＋90%11扭矩张力摩擦力Frictionevolution影响摩擦力的因素Coefficientoffrictiononthethread螺纹间的摩擦系数12螺栓表面螺帽表面干燥轻度浸油原始原始0.18-0.350.14-0.26涂磷原始0.25-0.400.17-0.30镀锌原始0.11-0.360.11-0.20涂磷涂磷0.13-0.240.11-0.17镀锌镀锌0.18-0.420.13-0.22TorqueversusTension扭矩和张力Torque扭矩NmTension张力KN10202030405060406080100120medium-oiled,轻度浸油well-oiled,充分浸油rough/notoiled原始状态TensiondispersalTensiondispersal张力的散布误差张力的散布误差±50%±50%Finaltorque目标扭矩±2%由此得出一个重要的结论：如果其它的因素不能控制，仅仅控制扭矩是远远不够的！13Minimumtorque最小扭矩最小扭矩需求•部件之间的夹紧力必须大于其外部负载。•还需留有安全余量，考虑:–振动–摩擦力的变化–材料的尺寸–扭紧的精度14Maximumtorque最大扭矩角度扭矩•施加过大的扭矩势必加大螺栓的塑性变形•安全余量应考虑:–扭紧方法的精度–螺栓的质量最大的螺栓允许扭矩15最大扭矩点ISO5393连接的硬度•硬连接–α<30°•中性连接–30<α<720°•软连接–α>720°扭矩100%螺栓开始受力<30°>720°α,角度硬软05%达到目标扭矩16Tighteningcycle螺栓扭紧过程分析•Fastenerfinding(Searchsocket)寻帽•Rundown快速旋进•Elasticarea.线性区•Semi-elasticarea.半线性区•Plasticzone.塑变区Rundown快速旋进Torque扭矩Angle角度Elasticarea线性区constantslope斜率Finding寻帽yieldpoint屈服点ΔTΔαPlasticzone塑变区Final最终扭紧17螺栓扭紧过程-贴合面快速旋进最终扭紧扭矩测量•动态扭矩–在螺栓拧紧的同时用在线式扭矩传感器测量，如右图。•静态扭矩–螺栓安装后用扭矩扳手测量，如下图静态扭矩T(Nm)时间降落原因：静态摩擦力扭力扳手(静态扭矩)工具输出(动态扭矩)120-110-100-80-60-40-20-10-0-使用扭力扳手时可能会出现的问题•只能检查扭矩是否太低•同时受静态摩擦力影响•操作者不喜欢使用(生产效率低、人机工程问题)•必须定期校准•测力扳手的误差较大Inasummary小结1)ThetighteningtorquehastobeaccurateConditionstoachieveagoodclampingforce:ClampforceFrictioninthreadsFrictionundernutorhead2)Thequalityvariationofthejointmustbecontrolled24Whatyouwilllearn•Basisontightening...