Tech Briefs
Looming warmth

The medium-wave infrared pad pre-heating unit on the Jaguar S-type production line.

When Jaguar started manufacture of its new S-type sedan, production-line workers sometimes experienced difficulty in maneuvering semi-rigid wiring looms into position through an access panel. To ensure that production line speed criteria were met, an extra worker was sometimes needed to assist with fitting. Jaguar worked with supplier Heraeus Noblelight to find a solution. It was discovered that heating the looms would make them more pliable.

A portable infrared unit was provided for on-site trials that led to a full-scale infrared oven being designed and built by Heraeus. It was installed adjacent to the loom fitting point on the production line and is comprised of four, fast-response medium-wave emitters with a total power rating of 30 kW (40 hp), operating at about 15 kW (20 hp), fitted into a purpose-built housing and cooled by an axial fan. Below the housing is a drawer with a telescopic slider system to enable repeated operation. Looms are loaded into the drawer and an inductive proximity switch detects the drawer position and initiates the heating cycle when the drawer is closed. Power to the emitters is regulated by a thyristor to avoid overheating. The emitters switch on and off in less than 3 s to ensure they are operational only during the timed heating cycle of 2.5 min, which matches production-line speed. Loom fitting times for the S-type have been reduced and the ergonomics of the entire operation improved.

The company's infrared technology has also been applied to the fitting of water-shedding pads (to prevent water ingress) to the doors of the car. To improve pad adhesion, Jaguar looked at the possibility of pre-heating the pads to allow the adhesive to release more freely. Heraeus supplied a free-standing pre-heater unit. Properties of the pads were optimized if pre-heated to 40° to 50°C (104° to 122°F) before being positioned on the vehicle.

Stuart Birch