L20 Timing Belt Automatic Setting
Previously belt tension setting had been undertaken by using weighted bars which were applied to the tension setting idler pulley. 3 different bars were in use for differing engine variants. The bars were heavy (up to 20kg) and were not liked by the line operators. Even though a constant force to the belt was being applied, belt tension was not being set within the target limits, as the tensioning idler pulley was tilting during the tensioning process.
The active face of the tool which locates with the engine is fully floating, as positional accuracy of the engine could not be assured to better than +/- 3 mm in practice. Once located an air cylinder clamps the active face to the engine.
The engine conveyor is interlocked with the CLAVIS equipment, so that the engine can only advance to the next station when the tool is in the locked back position. Under normal operation engine variant is selected automatically by PLC input. However this may be over-ridden by manual selection.
