ZF Steering Systems Nacam UK supplies adjustable steering columns for the new Renault Modus. In terms of quality assurance,the design of this unit requires the 'slide load' to be measured in relation to the distance the column is extended (not simply the force needed), so Nacam had to adapt its existing inspection system. The company called in sensor specialist, Kistler to help develop the new test rig, which checks each and every steering column that comes off the production line.
The force needed to extend and retract the telescopic column in relation to distance is determined by a combination of two sensors: a precision piezoelectric force sensor and a linear displacement transducer. Force is measured continuously throughout the travel, and the signals from these devices are fed to a Kistler programmable CoMo Net monitoring system, which provides an output to reject any column that falls outside of the specification. Rejected steering columns are disassembled and reusable parts are returned to the production line to minimise wastage.