Rexroth Tightening System 350 System Documentation - Rhino ...

9 Tightening Processes Tightening Technology | Bosch Rexroth AG 213/3169.2 Tightening program stepsNoteThe Time monitoring function that is activated as standard must be greater than the tightening time in orderfor the tightening case to be evaluated as OK.Yield point A bolted connection is tightened until it reaches the yield point for the bolt (see page 238).InputExternal control of the tightening process is possible with this target function. The tightening step is endedwhen the UsrIn1/2 input changes from 0 to 1.Assignment of the UsrIn1/2 inputs to a physical input is done in the PLC assignment table (seepage 240).9.2.2.3 Additional functionsAdditional parameters necessary for the tightening step, which have an influence on the tightening process(e.g. start suppression), but cannot interrupt it, are set in this group field.SpeedThe speed (= set speed) with which this tightening step should be tightened must be set in this entryfield. A negative speed means counterclockwise revolution, a positive speed means clockwise revolution.NoteSpeed = 0 is only permitted if the Time or Input target function has been selected. In all other cases, thespeed (= set speed) may not be 0.ExampleA waiting or standstill period may be implemented within the tightening process with the Time targetfunction and Speed = 0. The waiting or standstill period in Fig. 9–9 is two seconds.Figure 9–9:Example parameterization of a tightening step for a waiting or standstill period of two secondsWARNING!Motor overheatingToo-long waiting or standstill periods during a tightening process may lead to the motor overheating!⇒ Select sufficiently short waiting or standstill periods.Start suppressionThe start suppression is the time in ms after the tightening step has been started during which the tighteningprocess is not monitored. This suppression is necessary to ignore torque peaks that are caused bythe inertia of masses. Reasons for too-large torque peaks could include:– Large speed jumps, e.g. acceleration from n = 0 to 500 rpm– Braking after the tightening from e.g. n = 500 rpm to 50 rpmUsually, the preset value of 30 ms does not need to be changed. This time must be changed, however, iflarge masses (e.g. special chucks) are attached to the output drive or the tightening step is very short(hard tightening case). Values between 0 and 100 ms can be set.Torque thresholdThis field for entering the torque threshold is only visible if the tightening step has an angle function setas a target or monitoring function (Fig. 9–8).System 350 | 3 608 878 040/05.2008