Rexroth Tightening System 350 System Documentation - Rhino ...

236/316 Bosch Rexroth AG | Tightening Technology 9 Tightening Processes9.3 Tightening processesThe target, monitoring, and additional functions for some select tightening programs are described in thefollowing. The objective of programming, i.e. tightening, is to maintain the clamp force 1) of a bolt until theend of its service life.9.3.2 Torque-controlled tightening processesTorque is the most easily accessible measured quality in tightening technology, which is why this tighteningprocess is easy to handle. Here, the torque is controlled and the angle of turn monitored.The torque-controlled tightening process offers the following advantages:– Easily accessible measured quality (= torque)– Use of standard bolts– Reusability of bolts (bolts are only deformed in the elastic range).The torque is directly measured at the bolt during the tightening process and recorded by the measurementtransducer on the tightening spindle.Function[Nm](1)T+MoT P MzT– MuTMssA– A+0W– W+[o]Figure 9–43:T = f (A), torque-controlled, angle of turn-monitored tightening process(1) Angle safety limitThe torque increases from positioning of the bolt head, exceeds the torque threshold Ts, that starts anglecounting and reaches the target parameter T P , after which the tightening process is ended. The torquethreshold Ts should be at the beginning of the linear increase of the tightening graph (as the joining processesof the tightening parts are almost complete here).1) The clamp force (also mounting clamp force) stretches the bolt during tightening and clamps togetherthe parts to be tightened. It is effective from the point that the bolt head or nut is positioned on thematerial to be tightened.System 350 | 3 608 878 040/05.2008