Atlas-Copco基本擰緊技術(shù)課件

1、BASIC TIGHTENING TECHNIQUE基本擰緊技術(shù)AC Tightening Technique阿特拉斯科普柯擰緊技術(shù)1BASIC TIGHTENING TECHNIQUE基本擰基本擰緊技術(shù)介紹裝配過程中的基本問題，為正確和使用選擇工具提供指導(dǎo)對客戶來講，成功的關(guān)鍵是所使用的工具設(shè)備能夠匹配其特定需要 2基本擰緊技術(shù)介紹裝配過程中的基本問題，為正確和使用選擇工具提Different ways of assembling裝配的不同方法Welding(焊接)Gluing(粘接)Riveting(鉚接)Tightening with screws and bolts(螺栓擰緊連接)3D

2、ifferent ways of assembling裝配Why use bolted joints?為什么使用螺栓連接Easy and quick assembly(簡單方便)Can be disassembled and reassembled(可以拆卸和重新裝配)Standardised well-defined element(標(biāo)準(zhǔn)化)Cost-efficient(節(jié)省成本)The bolt should be weakest link(設(shè)計成最薄弱環(huán)節(jié))Its so easy thata child can do it4Why use bolted joints?為什么使用螺栓連Th

3、e thread creates the clamp load that holds the joint together螺紋建立夾緊載何使得工件被夾緊)Clamping forceTensionTurning the nut or screw stretches the screw(旋轉(zhuǎn)螺母或者螺栓拉深螺栓)Stretching the screw clamps the parts together(拉伸螺栓保證工件夾緊)The clamp load in the joint is the target of all tightening(夾緊載何就是我們的擰緊的目標(biāo))5The thread

4、 creates the clamp lClamping force vs tensile load and shear load夾緊力和螺栓張力和剪切力Shear loadShear loadTensile loadTensile loadClamping force6Clamping force vs tensile loadThis must be avoided!這個必須要避免Shear loadShear loadTensionTension7This must be avoided!這個必須要避免Sh88Bolt tension = 20 kN9Bolt tension = 20

5、kN9Bolt tension = ?ton10Bolt tension = ?ton10Bolt tension = ?ton= 10 kN11Bolt tension = ?ton= 10 kN11Is the bolt tension now approximately.現(xiàn)在螺栓的拉伸力大約是多少?10 kN? 20 kN?Or 30 kN?12Is the bolt tension now approxThe Correct answer is: 正確的答案是:20 kN the bolt pretension will NOT change (much)螺栓上承受的拉伸力是不會變化的

6、13The Correct answer is: 正確的答案是:The Special Fastener特殊模式14The Special Fastener14The Use of the Special Fastener擰緊這個模式15The Use of the Special FasteneThe Joint Loaded by an Applied Force連接負(fù)載被一應(yīng)用的力產(chǎn)生16The Joint Loaded by an AppliedThe Joint Loaded by an Applied ForceZero clamp at the interface.界面中沒有夾緊

7、17The Joint Loaded by an AppliedThe Joint Loaded by an Applied Force18The Joint Loaded by an AppliedQuestionWhat is the major difference between a bolted joint on one hand and a welded, glued or riveted joint on the other hand?螺栓連接和焊接鉚接粘接有什么最大的區(qū)別And what is the consequence of this difference?這個不同點有什

8、么重要的19QuestionWhat is the major diffQuestionWhat is the major difference between a bolted joint on one hand and a welded, glued or riveted joint on the other hand?THE BOLTED JOINT IS PRELOADED!螺栓連接有預(yù)加負(fù)載And what is the consequence of this diffference?20QuestionWhat is the major diffQuestionWhat is th

9、e major difference between a bolted joint on one hand and a welded, glued or riveted joint on the other hand?THE BOLTED JOINT IS PRELOADED!And what is the consequence of this diffference?ONLY A SMALL PORTION OF THE EXTERNAL LOAD IS TRANSFERRED TO THE BOLT (until the preload is exceeded) !只有很小的一部分外部負(fù)

10、載被轉(zhuǎn)移到螺栓上(直到超過預(yù)加負(fù)載)21QuestionWhat is the major diffQuestionWhat is the major difference between a bolted joint on one hand and a welded, glued or riveted joint on the other hand?THE BOLTED JOINT IS PRELOADED!And what is the consequence of this diffference?ONLY A SMALL PORTION OF THE EXTERNAL LOAD IS

11、TRANSFERRED TO THE BOLT!INTERESTING BUT WHAT IS THE VALUE OF THAT? 意義-但是這個價值是什么22QuestionWhat is the major diffVariations in external loads are only to a small extent transferred to the bolt = The fatigue resistance of the bolt becomes very high外部負(fù)載的變化只有很小的一部分會轉(zhuǎn)移到螺栓上=這樣螺栓就不容易由于負(fù)載的交變而產(chǎn)生疲勞損壞It provide

12、s a frictional grip = It will not come apart if the parts cannot move in relation to each other提供了一個有摩擦力的夾緊=這將不會出現(xiàn)部件分離如果部件不能有相互的位移23Variations in external loads a螺栓連接的受力剪切拉伸24螺栓連接的受力剪切拉伸24一定要確保施加的扭矩達到最小需要扭矩夾緊力一定要高于外部載荷安全余量載荷的影響因素:振動摩擦力的變化 連接件尺寸變化擰緊精度25一定要確保施加的扭矩達到最小需要扭矩夾緊力一定要高于外部載荷施加的力不要超過使用極限螺栓拉伸量N

13、夾緊力施加的力過大會使螺栓過度伸長安全余量取決于:擰緊精度材料等級26施加的力不要超過使用極限螺栓拉伸量N施加的力過大會使螺栓過度螺栓連接應(yīng)用的歷史背景27螺栓連接應(yīng)用的歷史背景27歷史背景十九世紀(jì)工業(yè)革命開始，為得到更大的生產(chǎn)力要求工業(yè)產(chǎn)品必須達到：系統(tǒng)化質(zhì)量可控性可復(fù)制性28歷史背景十九世紀(jì)工業(yè)革命開始，為得到更大的生產(chǎn)力要求工業(yè)產(chǎn)品連接圖德國人Rotscher 在1927年提出了連接圖，這種方法直到今天仍在使用，幫助我們理解連接的力學(xué)特性和進行計算。29連接圖德國人Rotscher 在1927年提出了連接圖，這種VDI 2230， 德國工程師協(xié)會 2230標(biāo)準(zhǔn)基于從1960年代就開始的研

14、究，德國工程師協(xié)會(VDI， German Society of Engineers)發(fā)布了VDI2230：高負(fù)荷連接的系統(tǒng)計算方法 Systematic Calculation of High Duty Joints.30VDI 2230， 德國工程師協(xié)會 2230標(biāo)準(zhǔn)基于從196VDI 2230使用范圍VDI 2230的應(yīng)用非常廣泛，包括帶60度法蘭的高強度螺拴，螺絲大小從M4到M39。它給出的是單螺拴連接的分析指導(dǎo)。由多個螺拴組成的連接，負(fù)荷首先要被分配，使每個螺拴上的負(fù)荷確定下來。31VDI 2230使用范圍VDI 2230的應(yīng)用非常廣泛，包連接件圖螺拴與連接件的關(guān)系拉伸彈簧壓緊彈簧3

15、2連接件圖螺拴與連接件的關(guān)系拉伸彈簧壓緊彈簧32連接件圖力伸長量壓縮量螺栓拉伸連接件壓縮壓力拉力螺拴和連接的變形33連接件圖力伸長量壓縮量螺栓拉伸連接件壓縮壓力拉力螺拴和連接的連 接 圖 解螺栓連接的變形關(guān)系 夾緊力 變形預(yù)緊力螺栓伸長1 連接件 壓縮2 34螺栓連接的變形關(guān)系 夾緊力 變形預(yù)緊力螺栓伸長1 連接件Joint Diagrams連 接 圖 解軸向工作載荷的影響 力12 變形螺栓受力增加部分夾緊力減少部分1 工作載荷35Joint Diagrams軸向工作載荷的影響 力12 通過螺紋產(chǎn)生夾緊力把連接件夾緊旋轉(zhuǎn)螺母或螺絲使螺絲受力伸長螺絲伸長產(chǎn)生的夾緊力把連接件夾緊我們需要的是連接件

16、中的夾緊力36通過螺紋產(chǎn)生夾緊力把連接件夾緊旋轉(zhuǎn)螺母或螺絲使螺絲受力伸長3Torque measurement扭矩測量The applied torque is measured應(yīng)用力矩Clamping forceNeeded需要的夾緊力Clamping force is the aim at but it is hard to measure.Torque is easy to measure and apply.夾緊力是目標(biāo)但是比較難測量但是扭矩比較容易測量37Torque measurement扭矩測量The applTorque T=FxrrFTa rFTbTa=FrTb= FrRes

17、ult: Ta= 2 TbF = applied force (in Newton)r = lever length (in meters)38Torque T=FxrrFTa rFTbTa=FrTb為了擰緊螺栓, 必須施加力以便擰緊螺母/螺絲39為了擰緊螺栓, 必須施加力以便擰緊螺母/螺絲39Clamping force depends on torque and other factors 夾緊力的因素是扭矩和其余的因素Fm= T/ (0.16P + (g * 0.58 * d2) + (Dkm/2) * k)Definitions:Fm = clamping force夾緊力P = pi

18、tch of thread螺距g = friction value in thread;螺紋摩擦系數(shù)d2 = diameter bolt螺紋中徑Dkm= size of surface bolt (nut)-head螺栓頭小表面尺寸Dkm = (dw + dh)/2 k= friction value surface bolt-head螺栓頭下的摩擦系數(shù)40Clamping force depends on torq50 %10 %40 %Friction betweenthread bolt andthread nut螺紋和螺帽的摩擦力Clamping force夾緊力 Friction u

19、nder bolt-head螺栓頭下的摩擦力50%40%Relation between applied torque and clamping force扭矩和摩擦力的關(guān)系4150 %10 %40 %Friction betweenClChanging friction:bolt-head螺栓頭下的摩擦力變化Teflon washer塑料惦片42Changing friction:bolt-head螺栓40 %20 %40 %40%40%Teflon washer塑料墊片F(xiàn)riction betweenthread bolt andthread nut螺紋和螺帽的摩擦力Clamping fo

20、rce夾緊力 Friction under bolt-head螺栓頭下的摩擦力Relation between applied torque and clamping force扭矩和摩擦力的關(guān)系4340 %20 %40 %40%40%Teflon washeLess friction:40 %20 %40 %44Less friction:40 %20 %40 %44Changing friction:bolt-head螺栓頭下的摩擦力變化Locking washer防松墊片45Changing friction:bolt-head螺栓60 %0%40 %60%40%Locking wash

21、er防松墊片F(xiàn)riction betweenthread bolt andthread nutClamping force Friction under bolt-headRelation between applied torque and clamping force扭矩和摩擦力的關(guān)系4660 %0%40 %60%40%Locking washerMore friction60 %0%40 %47More friction60 %0%40 %47Changing friction:thread bolt - nut螺紋的摩擦力變化Oil on the threads加油48Changing

22、 friction:thread bolt50 %20 %30 %50%30%Oil on threadsFriction betweenthread bolt andthread nutClamping force Friction under bolt-headRelation between applied torque and clamping force4950 %20 %30 %50%30%Oil on threaLess friction:50 %20 %30 %50Less friction:50 %20 %30 %50Changing friction:thread bolt

23、 - nutCorroded bolt銹51Changing friction:thread bolt50 %0 %50 %50%50%Rusted boltFriction betweenthread bolt andthread nutClamping force Friction under bolt-headRelation between applied torque and clamping force5250 %0 %50 %50%50%Rusted boltFrMore friction50 %0%50 %53More friction50 %0%50 %53Other way

24、s of changing the friction?Liquid loctite液體樂泰螺紋膠Locknut防松螺帽Paint in the threads螺紋中含有油漆Damaged threads損壞的螺紋Welding pearls焊渣Bolt finishing (Cr6, Dacromet, etc.)54Other ways of changing the friLoctite55Loctite55Locknut56Locknut56Paint on the threads57Paint on the threads57Damaged threads58Damaged threa

25、ds5850-40-10 規(guī)則 扭矩100%90% 的扭矩用于克服摩擦力夾緊力10%螺紋副中40%螺栓頭下摩擦力 50%5950-40-10 規(guī)則 扭矩100%90% 的扭矩用于夾緊力與摩擦力的關(guān)系一般情況下螺栓頭下摩擦力50%螺紋副中摩擦力40%10%在螺栓法蘭面上加潤滑油螺栓頭下摩擦力45%螺紋副中摩擦力40%夾緊力15%螺紋副中有雜質(zhì)或螺紋受損螺栓頭下摩擦力50%螺紋副中摩擦力45%5%60夾緊力與摩擦力的關(guān)系一般情況下螺栓頭下摩擦力50%螺紋副中螺栓標(biāo)識系統(tǒng)生產(chǎn)商標(biāo)識第一個數(shù) = 1/100 的最大抗拉強度 (N/mm2)1008 = 800 N/mm2 第二個數(shù) =屈服強度與最大抗拉

26、強度之間的關(guān)系 0.8 = 80%兩數(shù)相乘得出屈服應(yīng)力 800* 0.8 = 640 N/mm2 公制螺紋.61螺栓標(biāo)識系統(tǒng)生產(chǎn)商標(biāo)識公制螺紋.61施加的力不要超過使用極限螺栓拉伸量N夾緊力施加的力過大會使螺栓過度伸長安全余量取決于:擰緊精度材料等級62施加的力不要超過使用極限螺栓拉伸量N施加的力過大會使螺栓過度6363軟連接和硬連接64軟連接和硬連接64Torque = OK夾緊角: 65Torque = OK夾緊角: 65硬連接的定義 (ISO 5393)30 max.夾緊角66硬連接的定義 (ISO 5393)30 max.夾緊角66硬連接舉例Clamping forceSteep sl

27、opeAngleLow angle displacement67硬連接舉例Clamping forceSteep slope720 min.軟連接軟連接的定義 (ISO 5393)68720 min.軟連接軟連接的定義 (ISO 5393)6軟連接舉例Clamping forceSoft slopeAngleHigh angle displacement69軟連接舉例Clamping forceSoft slopeA連接的特性也決定著所需工具的類型(ISO 5393) 旋轉(zhuǎn)角度目標(biāo)扭矩A. 硬連接：到達貼合點后，旋轉(zhuǎn)30以內(nèi)達到目標(biāo)扭矩的連接。B. 軟連接：到達貼合點后，旋轉(zhuǎn)2 圈（720）以

28、上達到目標(biāo)扭矩的連接。扭矩的過扭程度受連接件硬度以及工具轉(zhuǎn)速影響。軟連接、硬連接3072070連接的特性也決定著所需工具的類型(ISO 5393) 旋轉(zhuǎn)TAngle ( )Snug levelTAngle ( )Snug level硬連接 720 deg (ISO 5393)X NmX Nm 72071TAngle ( )Snug levelTAngle (扭矩過沖10 Nm9 Nm工具雖然設(shè)定都是9Nm，但是針對不同性質(zhì)的連接會產(chǎn)生不同的結(jié)果72扭矩過沖10 Nm9 Nm工具雖然設(shè)定都是9Nm，但是針對不軟、硬連接目標(biāo)均值偏差扭矩角度過扭貼合點硬連接軟連接73軟、硬連接目標(biāo)均值偏差扭矩角度過

29、扭貼合點硬連接軟連接73如何在一個連接件上測量扭矩動態(tài)扭矩:在擰緊螺栓的同時用在線式扭矩傳感器測量。 靜態(tài)扭矩:安裝后用扭矩扳手測量。74如何在一個連接件上測量扭矩動態(tài)扭矩:在擰緊螺栓的同時用在線式靜態(tài)扭矩動力工具輸出扭矩 92949192949292X=92,43=1,13扭力扳手靜態(tài)扭矩 103 106 103 100 100 103 100X=102,14=2,27T (Nm)時間20406080100110120(A)工具輸出 (動態(tài)扭矩)(B) 扭力扳手 (靜態(tài)扭矩)原因:靜態(tài)摩擦力75靜態(tài)扭矩T (Nm)時間20406080100110120(硬連接上由于較高的靜態(tài)摩擦力，靜態(tài)扭矩

30、可比動態(tài)扭矩要高。右下圖中倒V的拐點即是扭力扳手測得的硬連接上的靜態(tài)扭矩76硬連接上由于較高的靜態(tài)摩擦力，靜態(tài)扭矩可比動態(tài)扭矩要高。裝配手測(動態(tài))(靜態(tài)) 102.6 112 102.6 110 101.4 111 101.2 110 102.4 113 100.9 109 102.1 110 102.4 111 101.0 113 101.8 112 101.84 111.1 0.67 1.4 2.01 4.1 均值 標(biāo)準(zhǔn)偏差 (Sigma) 3 Sigma硬連接77裝配手測均值 硬連接77軟連接靜態(tài)扭矩較動態(tài)扭矩要偏小，原因是衰減。VDI2230里系統(tǒng)的方法設(shè)置螺拴即有計算扭矩衰減這一步

31、驟78軟連接靜態(tài)扭矩較動態(tài)扭矩要偏小，原因是衰減。VDI223If we look at what happens to the surface in contact with the threads and under the head, we will notice that locally the load can be extremely high, far exceeding yield and these areas will collapse (embedment). Embedment reduces the clamping force because the elongat

32、ion of the bolt is reduced.Very high load Very high loadAverage load (80% of yield)扭矩衰減 copyright BLM s.a.s - 24 giugno 2004QUIT79If we look at what happens to 扭矩衰減的原因呢 連接的嵌入80扭矩衰減的原因呢 連接的嵌入808181Calculation Step R4 - Establishing Preload Losses計算步驟R4確定預(yù)加負(fù)荷損失losses.由于局部嵌入和不同的熱膨脹特性，螺拴預(yù)加負(fù)荷可能會損失Alumini

33、um JointSteel Bolt82Calculation Step R4 - Establis彈性衰減會影響夾緊力材料彈性衰減會使夾緊力衰減!Time83彈性衰減會影響夾緊力材料彈性衰減會使夾緊力衰減!Time83均值 標(biāo)準(zhǔn)偏差 (Sigma) 3 Sigma裝配手測(動態(tài))(靜態(tài)) 100.2 88 100.5 84 100.7 92 100.3 86 100.4 90 100.8 88 100.5 86 100.2 85 100.2 84 100.4 84 100.42 86.7 0.21 2.8 0.63 8.3 軟連接84均值 裝配手測軟連接84衰減 60-70%的衰減發(fā)生在30

34、毫秒以內(nèi)時間牛米衰減斷氣85衰減 60-70%的衰減發(fā)生在30毫秒以內(nèi)時間牛米衰減斷氣8扭矩和角度 OK扭矩角度扭矩 = OK角度 = OK86扭矩和角度 OK扭矩角度扭矩 = OK86結(jié)論：Clamp forceFriction in threadsFriction under nut or head螺栓裝配質(zhì)量對產(chǎn)品的最終質(zhì)量有著直接影響為了得到質(zhì)量合格的擰緊連接擰緊扭矩必須精確連接件質(zhì)量必須得到監(jiān)控87結(jié)論：Clamp forceFriction in thre擰緊方法的分類按工具控制方式基于扭矩或角度:彈性范圍內(nèi):扭矩控制角度控制連接控制超出彈性范圍角度控制梯度(扭矩變化率)控制，即屈

35、服點控制其他方式超聲波機械測試伸長量88擰緊方法的分類按工具控制方式基于扭矩或角度:88夾緊力角度扭矩角度螺拴連接模型89夾緊力角度扭矩角度螺拴連接模型89夾緊力扭矩角度角度螺拴連接模型塑性變形階段90夾緊力扭矩角度角度螺拴連接模型塑性變形階段90扭矩控制91扭矩控制91扭矩控制方式利用的是人們熟知的扭矩與張緊力之間的關(guān)系公式。扭矩控制方式在出現(xiàn)最大摩擦系數(shù)和最小力率(Force Rate)時提供最小的夾緊力，反之亦然。扭矩控制92扭矩控制方式利用的是人們熟知的扭矩與張緊力之間的關(guān)系公式。扭優(yōu)勢:容易實現(xiàn)不同精度等級的控制+/-25%的脈沖型工具到+/-1%的擰緊軸巨量的產(chǎn)品和過程設(shè)計的標(biāo)準(zhǔn)數(shù)據(jù)-歷史悠久過程和設(shè)備的有效性校驗過程非常容易 工程師非常熟悉，廣為人知扭矩控制93優(yōu)勢:扭矩控制93Tightening Methods劣勢: 夾緊力的精度很差,可能到+/- 60 %,受摩擦系數(shù)影響大 沒有根本辦法防止螺拴斷裂以上兩個原因?qū)е侣菟┠芰寐实?60%扭矩控制94T