Torquestar Ensures Quality Of Sun Roof Assemblies

March 1998
Inalfa Roof Systems supplies sun roof assemblies to most of the world's car and truck manufacturers, including General Motors, Jaguar, BMW, Iveco, Scania, Rover and JCB. Quality is paramount and one implication of this is that every threaded fastener must be tightened to a specified torque - too loose and the assembly might rattle, too tight and the threads could be stripped. Every screw is fastened using a pneumatic wrench so that the torque can be controlled, and each gun is checked daily. To carry out this check therefore requires a simple-to-use, accurate, reliable and robust piece of equipment. Inalfa selected the TorqueStar Type III torque auditor and a torque transducer from Crane Electronics. Both of these items have been mounted on a trolley to make them easier to transport around the production lines.

“Until a couple of years ago we used a torque tester which was unreliable and, to be honest, was not supported well by the supplier,”� explains Pat Flanagan, the Warranty Technician at Inalfa. “When we were looking for something better we found that many of our customers were using TorqueStars. We had a demonstration of the equipment here on site and it did everything we wanted it to. It was simple to use and it was a reasonable price”�.

Inalfa's factory in Tamworth is split into two halves. For one half the quality technician starts work in the morning, one hour prior to production, checking each of the guns on the line and adjusting and rechecking them if necessary. The other half of the factory has the guns checked in the afternoon, during production, by a second technician. At the end of the week the data is downloaded from the TorqueStar to a PC to enable SPC and other analysis to be carried out.

The TorqueStar has been pre-programmed with 'rounds' so that, as the quality technicians tour the production lines, there is a prompt from the TorqueStar to show which gun should be checked next. If the wrong gun is selected the TorqueStar sounds a warning alarm. This simplicity of operation helps to eliminate errors and ensures that the whole operation is carried out as quickly as possible - particularly important when guns are being taken from the production line for testing.

Pat Flanagan says: "The TorqueStar has paid for itself and has never given us a problem. Once it has been set up, it is so easy to use that you just can't go wrong".