Crane Monitoring Keeps Cummins On Track Ten Years On

1997
A torque testing trolley system supplied by Crane Electronics Ltd., Hinckley to Cummins Engine Co. Ltd., Darlington, is continuing to provide accurate, reliable monitoring over a decade after it was purchased. During that time the system, which is based on a Crane UTA universal torque analyser and associated joint simulators and transducers, has always been found to be accurate when subject to periodic calibration by the company's gauge calibration department.

Cummins is one of the world's leading manufacturers of diesel engines and has three factories in the UK. The Darlington plant is tasked with manufacture of engines in the 50 Bhp to 525 Bhp range for use in agricultural and HGV automotive applications. Much of its production goes for export, notably to mainland Europe and South Korea. Since the factory was heavily re-equipped during the mid-eighties, the company has operated an assembly information management system - AIMS - which archives critical assembly parameters for every unit manufactured against the engine serial number as part of its quality assurance programme. All of the on-line nut runners and other torque equipment are networked via their controllers to feed data into the AIMS room, where the necessary data is logged automatically.

Says Ian Rutland, Senior Gauge Technician: “To ensure that the torque values being supplied into AIMS were correct it was necessary also to have an independent means of checking the shop floor systems. The Crane UTA package was bought in for this purpose and is used by the area quality representatives to ensure that the equipment in use in their area is functioning correctly.”

Engine production at Cummins is based on team work, with the teams distributed over eleven ‘areas’, each of which carries out certain assembly or finishing tasks. Of these, five areas are concerned with operations demanding use of torque equipment. The trolley package developed and supplied by Crane incorporates two fixed joint rate simulators based on Belleville washers with integral transducers and three CheckStar-type loose transducers which are used in conjunction with a threaded plate which is integral with the trolley, and are also used on line. The area quality representatives are responsible for a schedule of weekly and monthly checks according to the job requirements.

The mode of operation is to take ten readings using the trolley facilities and then go to the application and take ten readings with a transducer in-line with the tool. This confirms whether the production system is supplying the correct information to AIMS.

Says Mr Rutland: “It's a fairly rigorous auditing schedule and the Crane equipment is in virtually constant use, with re-calibration on a three month schedule. The information from it is currently printed out and archived separately from AIMS as it is used as an audit facility, a role in which it has proved very effective.”