Why use bolted joints?为什么使用螺栓连 接
It’s so easy that a child can do it
• Easy and quick assembly(简单方便) • Can be disassembled and reassembled(可以拆卸和重新装配) • Standardised well-defined element(标准化)
AC Tightening Technique
阿特拉斯·科普柯拧紧技术
BASIC TIGHTENING T E C H N I Q U E
基 本 拧 紧 技 术
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AC tightening technique
基本拧紧技术
介绍装配过程中的基本问题，为正确和使用选择工具提供指导
对客户来讲，成功的关键是所使用的工具／设备能够匹配其特定需要．
• 我们需要的是连接件中的夹 紧力
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AC tightening technique
Torque measurement扭矩测量
Clamping force is the aim at but it is hard to measure.
Torque is easy to measure and apply.夹紧力是目标但是比较难测量但是扭矩 比较容易测量
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AC tightening technique
Clamping force vs tensile load and shear load夹紧力和 螺栓张力和剪切力
Tensile load
Clamping force
Shear load Shear load
Tensile load
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AC tightening technique
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AC tightening technique
螺栓连接的受力
剪切
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AC tightening technique
拉伸
一定要确保施加的扭矩达到最小需要扭矩
• 夹紧力一定要高于外部载荷
• 安全余量载荷的影响因素: – 振动 – 摩擦力的变化 – 连接件尺寸变化 – 拧紧精度
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AC tightening technique
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AC tightening technique
VDI 2230－使用范围
VDI 2230的应用非常广 泛，包括带60度法兰的 高强度螺拴，螺丝大小 从M4到M39。
它给出的是单螺拴连接 的分析指导。由多个螺 拴组成的连接，负荷首 先要被分配，使每个螺 拴上的负荷确定下来。
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AC tightening technique
The applied torque is measured应用力矩
Clamping force Needed需要的夹紧力
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AC tightening technique
Torque T=Fxr
F
Ta
r F
Ta=Fr Tb= ½ Fr
Result: Ta= 2 Tb
TbБайду номын сангаас
½r
F = applied force (in Newton) r = lever length (in meters)
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AC tightening technique
Question
What 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!
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AC tightening technique
连接图
德国人Rotscher 在1927年提出了连接图，这种方法直到今天仍在使用，帮 助我们理解连接的力学特性和进行计算。
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AC tightening technique
VDI 2230， 德国工程师协会 2230标准
基于从1960年代就开始的研究， 德国工程师协会(VDI， German Society of Engineers) 发布了VDI2230：高负荷连接 的系统计算方法 － Systematic Calculation of High Duty Joints.
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AC tightening technique
Bolt tension = 20 kN
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AC tightening technique
Bolt tension = ?
ton
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AC tightening technique
Bolt tension = ?
ton
= 10 kN
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AC tightening technique
The Joint Loaded by an Applied Force
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AC tightening technique
Question
What is the major difference between a bolted joint on one hand and a welded, glued or riveted joint on the other hand?螺栓连接和焊 接铆接粘接有什么最大的区别 And what is the consequence of this difference?这个不同点有什么重要的
AC tightening technique
Is the bolt tension now approximately…….. 现在螺栓的拉伸力大约是多少?
10 kN? 20 kN? Or 30 kN?
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AC tightening technique
The Correct answer is: 正确的答案是:
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AC tightening technique
为了拧紧螺栓, 必须施加力以便拧紧螺母/螺丝
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AC tightening technique
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AC tightening technique
The Joint Loaded by an Applied Force连接负载被一应用的力产生
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AC tightening technique
The Joint Loaded by an Applied Force
Zero clamp at the interface. 界面中没有夹 紧
螺拴与连接件的关系
拉伸弹簧＋ 压紧弹簧
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AC tightening technique
连接件图
螺拴和连接的变形
压力 力
拉力
连接件压 缩
螺栓拉伸
压缩量
伸长量
连接件图
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AC tightening technique
螺栓连接的变形关系
夹紧力
预 紧 力
螺栓伸长δ1
连接件 压缩δ2
变形
连接图解
INTERESTING – BUT WHAT IS THE VALUE OF THAT? 意义-但是这个价值是什么
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AC tightening technique
Variations in external loads are only to a small extent transferred to the bolt => The fatigue resistance of the bolt becomes very high 外部负载的变化只有很小的一部分会转移到螺栓上=>这样螺栓就不容 易由于负载的交变而产生疲劳损坏 It provides a frictional grip => It will not come apart if the parts cannot move in relation to each other 提供了一个有摩擦力的夹紧=>这将不会出现部件分离如果部件不能有 相互的位移
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AC tightening technique
Question
What 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 TRANSFERRED TO THE BOLT!
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AC tightening technique
Question
What 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!螺栓连接 有预加负载 And what is the consequence of this diffference?
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AC tightening technique
Different ways of assembling装配的不同方 法
• Welding(焊接) • Gluing(粘接)