Rexroth Tightening System 350 System Documentation - Rhino ...

226/316 Bosch Rexroth AG | Tightening Technology 9 Tightening Processes9.2 Tightening program stepsStick slip[Nm](2)(1)TST=20 MST = 20[ o ]Figure 9–34:Stick slip monitoring function where T = f(A)(1) STS fallen below(2) Tightening process abortedTST Torque threshold for stick slip recordingFigure 9–35:Example parameterization for Stick slipStick slip is the undesired effect of continual change between static friction and sliding friction when tighteninga bolted connection. This effect results in torque peaks on the measurement transducer, caused bymoments of inertia (Fig. 9–34).The sliding friction phases are counted from the torque threshold TST (e.g. 20 Nm) (Fig. 9–35: max. 3xbelow (STS) TST = 20 Nm permissible). If the number of times the system may fall below this is exceeded,the monitoring function will report an error.TimeThe tightening time is monitored with the Time monitoring function until the target function is reached.This monitoring function is set to t = + 10 seconds as standard and is switching, i.e. the tightening processis immediately ended with an NOK evaluation if the set time is exceeded.9.2.4 NOK branch stepThis auxiliary step creates a branch in the tightening program process. It depends on the results from theprevious tightening step and can thus only be inserted in the run sequence after a tightening step.A new NOK branch step is inserted in the tightening program by clicking on the symbol on the left. Doubleclicking on the NOK branch step opens the corresponding dialog for entering the parameters (Fig. 9–36).If OK, the tightening process continues “straight”, i.e. in the same column.System 350 | 3 608 878 040/05.2008