Rexroth Tightening System 350 System Documentation - Rhino ...

9 Tightening Processes Tightening Technology | Bosch Rexroth AG 237/3169.3 Tightening processesAngle of turn monitoring (A–, A+) 1) is used for error recognition. The advantages of angle of turn monitoringinclude recognition of:– Lot jumps in bolts and components– Over-twisting of threads via a measurable angle of turn increase– Incompletely cut threadsUseThe torque-controlled tightening process is mainly used for:– Transmission assembly– Wheel assembly– Exhaust manifold assembly9.3.3 Angle of turn-controlled tightening processesThe angle of turn is controlled and the torque monitored in this process. Here, the bolt is permanentlydeformed.The angle of turn-controlled tightening process offers the following advantages:– Minimization of the dispersion of mounting clamp force, i.e. the tightening factor 2) is almost 1– A particularly high bolted connection strength can be attainedThe angle of turn recording is implemented in the measurement transducer.Function[Nm]T+ M+(1)T– M–Ts Ms(2)0AP Wz[o]Figure 9–44:T = f (A), angle of turn-controlled, torque-monitored tightening process(1) Angle safety limit(2) Tightening angle1) Limit value definition (A–, A+) should be done via a statistical evaluation (≥ 50 tightenings). Too-smalltolerance limits result in a high number of NOK tightening cases; too-large tolerance limits impair faultrecognition.2) Tightening factor =F Tmax /F Tmin = dispersion of the mounting clamp force (clamp force).System 350 | 3 608 878 040/05.2008