拧紧基础知识讲解-修改版ppt课件

1、拧紧机资料之一双锤式大型锤滚珠凸轮机构 Torque Readout Run down speed Two Hand Operation (angle wrenches)价钱适宜低过冲可反复性好运转速度下降双手操作本人读力矩扭矩推杆马达末端离合器弹簧离合器调理螺母螺丝起子准确噪音低清洁闭环反响人体工程学运转本钱低可以与控制系统和BCRs衔接初始投资高扭矩反作用两手操作拧紧战略可维修性动力源数据采集结合处的危险程度预算紧固件通道扭矩等级循环速率紧固件和驱动方式人机工程学的运用反作用力，工具分量，力臂位置，频率螺栓衔接的可靠性影响要素很多：紧固件质量和类型结合资料的一致性所用的工具安装方法或战略操

2、作人员的影响摩擦的传送螺栓夹紧力的坚持工具和装配方法的选择应在设计过程中及早进展，这样才最有效切真实实的检查动态拧紧扭矩Works Only in Tapped Holes这种方法只适用于螺纹孔Time Consuming耗费时间联络Only Gives Assurance That Inspected Fastener Has Been Tightened只能确定检测的紧固件曾经被拧紧Conditions收到操作者技艺程度和衔接条件的限制 Small Amount小幅度旋转紧固件之后可以真实地检测出动态扭矩Peak Static Torque静态扭矩峰值Residual Torque Mea

3、sured Dynamically剩余扭矩的动态丈量“SnugTorque“事宜扭矩Capture Angle2 - 4角度做720度的旋转(6.5的公差)。JOINT RATES AS DEFINED BY ISO 5393衔接率的定义由国际规范化组织衔接率的定义由国际规范化组织5393界定界定Joint rate highly effects the final clamp load achieved by a given torque衔接率对最后给定的夹负载力矩有很大的影响力衔接率对最后给定的夹负载力矩有很大的影响力Clamp Load (torque)Angle (Time)Clamp

4、 Load夹负荷夹负荷Angle-Self Locking 自锁功能-Damaged Threads-Damaged 螺纹破损PrevailingTorque现行扭矩现行扭矩SNUGTLTHTC力臂力臂(Feet, Meters) 英尺、米英尺、米力力(Newtons, Pounds)牛顿牛顿, 英镑英镑扭矩扭矩 = 力力 x 力臂力臂角度90Tightening Threaded Fasteners is Basically an Energy Transfer Process 螺纹紧固件紧固过程主要是是能量转移的过程Area Under Torque-Angle Curve is Prop

5、ortional to the Energy Required to Tighten the Fastener 扭矩角度曲线以下的面积与紧固件紧固所需的能量成正比。T = K d F T = Torque扭矩 d = Nominal Diameter名义直径 F = Force力 K = Friction Factor 摩擦系数角度, q扭矩, T螺纹摩擦力夹紧力螺栓头摩擦力扭矩螺栓头摩擦力螺栓头摩擦力 55%螺纹摩擦力螺纹摩擦力- 35%夹紧力夹紧力 - 10%JointRateientTorqueGradddT扭矩扭矩(夹紧力夹紧力)角度角度, qRundown破旧破旧Rundown: B

6、efore the bolt head/nut comes into full contact with bearing area在螺栓头在螺栓头/螺螺母完全接触轴承区域之前母完全接触轴承区域之前Plastic/Post-Yield塑性塑性/ 标杆标杆-效益效益Plastic/Post-Yield: Permanent deformation of fastener or possible yielding of threads, joint or gasket紧紧固件的永久变形或只是线程、固件的永久变形或只是线程、衔接或垫圈的构成衔接或垫圈的构成Elastic Clamping弹性夹紧弹性夹

7、紧Elastic Clamping: Constant torque/angle slope where energy is transferred from tool to assembly恒量扭矩恒量扭矩/斜斜率界定在能源问题转移到装率界定在能源问题转移到装配工具过程时配工具过程时Snug适宜适宜Snug: Fastener and joint mating surfaces are drawn into alignment 紧固件及衔接点表紧固件及衔接点表层要对齐层要对齐kdPT 扭矩扭矩(夹紧力夹紧力)角度角度, q扭矩控制拧紧扭矩控制拧紧Step 1: Apply a Torque

8、to Consolidate the JointComponents (Snug Torque) 第一步：施加扭矩来稳定部件的衔接 Step 2: Turn the Fastener Through a Pre-determined Angle第二步:旋转紧固件至预先设定的角度Originally Developed for Beyond Yield Tightening, Now Also Used in the Elastic Range最初是为了超出屈服区的拧紧,如今也用在弹性区内Requires Application Testing to Establish Snug Torque

9、and Angle Parameters 需求经过实验建立适宜的转矩和角参数Also known as: Turn of the Nut, Torque-Angle 也称为:螺母旋转法，扭矩-角度法Preload Accuracy 15%预紧力准确度15%角度控制kdPT 360pFpLow Angle Limit角度下线High Angle Limit角度上限Torque(Clamp Load)Angle, qkdTFp360ppFFused, the effect of constant preload v. angle is lost.条件允许时应尽量选用低的初始扭矩。而当运用一个高的初

10、始扭矩时,预紧力与转角的恒定关系将不再有效。A low snug torque will also reduce the effects of torque scatter before the angle is counted. 低的初始扭矩也会减小转角施加前的扭矩散失。When tightening in the plastic range of a fastener, variation in yield strength is also a factor.在紧固件塑性区内任务时，屈服强度的变化也是一个影响要素。屈服点控制屈服点控制 Preload Accuracy 8% 50% of

11、Peak Gradient50%的峰值梯度的峰值梯度Bolt Yield Point螺栓屈服点螺栓屈服点Torque(Clamp Load)夹负荷夹负荷Angle, qReduced Variation in Preload After Tightening:紧缩之后减少预负荷中的变形紧缩之后减少预负荷中的变形 PRELOAD, N,预负荷预负荷NThread线程线程GradeSizeRange8.810.912.98.810.912.94,4006,2007,3003.14.45.35,6007,6008,8004.367.27,20010,00012,2006.49119,20012,40

12、014,6008.7121510,20014,20016,10011141813,00017,60020,50015202418,60026,20031,40025374423,80032,20037,80036516029,80041,60050,00052738838,00051,20060,000719911943,40060,70072,9009212815654,40074,90087,70012717320759,40083,300100,00014420524475,600102,000120,00020028033582,500115,000,000228322383105,0

13、00141,000166,00031045052099,200,000167,000305430510127,000171,000201,000420595710Grade EXPECTED TORQUE, Nm预期的扭矩预期的扭矩,海里海里Clamp Load Scatter夹负荷分散精细力矩扳手精细力矩扳手M10气动冲击扳手气动冲击扳手M14气动定扭气动定扭矩扳手矩扳手M12电动扳手电动扳手屈服点控制屈服点控制M8 8%15%25%30 - 40%Joint May Not Be Critical Enough to Warrant its Cost 与所花的费用相比，接合不够重要Shou

14、ld Not Use When:以下情况不能运用：Bolt Yield Strength Joint Compressive Strength螺栓屈服强度大于结合抗压强度时Bolt Yields Somewhere Other Than Threads螺栓除螺纹以外的地方发生了屈服Head Shears螺栓头掉了Nut Strips螺母的螺纹剥离Applications Where Frequent Disassembly is Required频繁装配的场所Joints With Unpredictable Stiffness Qualities衔接的强度不可预知If Yield is th

15、e Most Accurate, Why Not Always Use it?假设屈服点控制是最准确的假设屈服点控制是最准确的, 为什么不常用呢为什么不常用呢?FOUR MAJOR ERRORS DURING BOLT TIGHTENING :螺栓紧固中的四大错：螺栓紧固中的四大错： Human errors 人为操作错误 Tightening method errors 紧固方法不当 Improper tool errors 工具不适宜 Joint parts errors 衔接部位错误Forgot to tighten忘记拧紧Improper tools used运用了不恰当的工具Wron

16、g specifications规格错误Wrong tightening procedure紧固方法错误Wrong selection of tools工具的选取不当Inaccuracy 不准确Mechanical failure 机械缺点Out of parts tolerance超出了部件的接受力Bad material资料不好Insufficient lubrication光滑不充分CLASSIFICATION & CAUSE FOR LOOSENING OF BOLTS螺栓松动分类及缘由螺栓松动分类及缘由CHARACTERISTICS DIAGRAM OF DEFECTIVE

17、JOINT缺陷衔接特缺陷衔接特征图征图装配过程中装配过程中由以下方法判别由以下方法判别:错误种类错误种类 扭矩控制扭矩控制 扭矩控制带扭矩控制带 角度监视角度监视 屈服点控制带屈服点控制带 扭矩和角度监视扭矩和角度监视 Bolt too Soft(Low or high friction conditions)摩擦过大或过摩擦过大或过小小NOYESYESBolt too Soft(Normal Friction)摩擦适中摩擦适中NOUsually NOYESBolt too Hard螺栓过硬螺栓过硬NONOYESThread Fault(Friction High)摩擦过大摩擦过大NOYESY

18、ESCoating/ Lube Fault (Friction extremely Low)摩擦微乎其微摩擦微乎其微NOYESYESAngle, qTorque, TExpectedTorqueAngleTightening CyclesTorque High LimitTorque Low LimitAngle High LimitAngle Low LimitAngle, qTorque, TExpectedTorqueAngleTightening CyclesTorque High LimitTorque Low LimitAngle High LimitAngle Low Limit

19、Angle, qTorque, TTorqueAngleTightening CyclesTorque High LimitTorque Low LimitAngle High LimitAngle Low LimitExpectedAngle, qTorque, TTorqueAngleTightening CyclesTorque High LimitTorque Low LimitAngle High LimitAngle Low LimitExpectedAngle, qTorque, TTorqueAngleTightening CyclesTorque High LimitTorq

20、ue Low LimitAngle High LimitAngle Low LimitExpectedAngle, qTorque, TTorqueAngleTightening CyclesTorque High LimitTorque Low LimitAngle High LimitAngle Low LimitExpectedAngle, qTorque, TEffect on Torque/Angle End of Cycle Data:扭矩扭矩/角最终的循环数据的作用角最终的循环数据的作用:TorqueAngleTightening CyclesTorque High LimitAngle High LimitAngle Low LimitTorque Low LimitAll final cycle data is good一一切的数据是有效的切的数据是有效的Expected期望Findings:Nuts yielded at Avera