COMMENTARY — `Smart’ vehicles count on copper

The use of copper and copper alloys in North American vehicles has risen sharply in the past decade. The amount of copper in the average vehicle increased to 51 lb. in 1991 from about 36 lb. in 1980, according to the Copper Development Association in the U.S.

The 40% increase has resulted from production of so-called “smart”vehicles, which require more copper wire in harnesses, electric motor windings and electrical connectors. Projections from current research on automotive electronics (such as that for a skid-preventing gyroscope) indicate that even more copper wiring will be needed.

An example of new technology requiring copper is the anti-lock braking system (ABS), which will be available on all General Motors (GM) vehicles by the mid-1990s. According to the product manager for anti-lock brake systems at the Delco Chassis division of GM in Dayton, Ohio, two pounds of copper wire are needed for the system to function.

Copper wire is used is several areas of the Delco system. They are: the wiring harnesses between the wheels and the system computer and from the computer to the hydraulic modulator, the windings of three direct-current motors at the hydraulic modulator, and the copper-wound speed sensors at each wheel. Cost, reliability and performance were the criteria for selecting copper, according to the manager.

Anti-lock brakes improve a driver’s ability to control the car and to stop in shorter distances by decreasing wheel lockup to a minimum during difficult braking conditions.

The ABS computer receives information from the sensors at each wheel, and it can then determine if a wheel is about to lock. When this occurs, the computer first reduces the brake pressure and then re-applies the brakes when the tire regains adequate traction. This action occurs many times per second and can be compared with pumping the brakes.

Non-electrical uses for copper in the average vehicle include the radiator and heater, oil-coolers and other heat transfer components, clutch and brake linings, plating, brass fittings and a variety of other small parts. — From a recent issue of “Canadian Copper,”the quarterly bulletin of Canadian Copper & Brass Development Association, Don Mills, Ont.