Rectification Relies On Readstar Torque Displays

January 2000
At its Ryton-on-Dunsmore plant near Coventry, the PSA Peugeot Citroen manufactures the new Peugeot 206 model in accordance with rigorous quality standards. Any faults that are identified during or after assembly are rectified in areas set aside from the production line. Many of these areas are equipped with torque monitoring equipment from Crane Electronics. These instruments include ReadStars, CheckStars, TorqueStars, static transducers and a WrenchMaster-D. There are also Crane instruments in the Service Technical Centre where engines are stripped, inspected and reassembled.

Within the rectification areas there are various wrenches for tightening fasteners to torques ranging from 1Nm to 120Nm. These wrenches are operator-adjustable and therefore have to be checked each time they are reset for another fastener. For this checking operation, Crane's ReadStars are used in conjunction with static transducers. ReadStars feature a clear read-out and the facility for downloading the data to a printer. The printed output, which also includes the date, time and the Readstar's serial number, is then attached to the vehicle repair record to ensure that full traceability is maintained.

One of the applications for the CheckStar in-line rotary transducers is in monitoring the torque that is applied by torque wrenches used in the rectification areas on safety-critical fasteners. Each day the wrenches are checked and the data is collected for SPC (statistical process control). The advantage of the CheckStar transducers - and there are around 20 at the Ryton plant - is that they monitor the true torque that is applied to the fastener in the actual assembly situation. To collect the torque data, TorqueStar torque auditors are used and these are capable of storing up to 20,000 readings for torque, angle, pulse and click.

Occasionally there will be a fastener that is inaccessible for the conventional wrench and CheckStar. To overcome this problem, PSA Peugeot Citroen uses Crane's WrenchMaster-D torque wrench, which gives an extremely accurate torque reading each time it is used.

Phil Curran, the Reliability Engineer in the Maintenance Department, has investigated other torque instruments but has always returned to Crane's: “All of their equipment is made to a very, very high standard and the service from Crane is also excellent. Really I would like to see more of their torque instruments on the production line, not just in the rectification areas.”� Mr Curran goes on to say: “We were subjected to an internal audit recently by someone from within the PSA group and they were very impressed by the ReadStars. I would be happy to buy any new products from Crane because, after ten years of using their equipment, I know it is accurate, reliable, robust and easy to use. I honestly believe that it is the best on the market.”�