Tech & Trends: Robo-Clamp: Dana's Hydroforming Answer

When Magna International Inc. landed a major contract to produce frames for the GMT800 full-size pickups and sport/utility vehicles (SUVs) from General Motors Corp., it was a crushing blow for Dana Corp., which had supplied frames for the previous-generation CK pickups for 10 years.

Dana lost the contract, as did Tower Automotive on the SUVs, partly because Magna had a valuable weapon in its technology arsenal: hydroforming.

Today, all suppliers in the business of bending metal - from exhaust pipes to frame rails - are beyond experimentation with the clean and efficient technology and are beginning to apply it to a growing number of new products.

Dana is one of those players banking heavily on hydroforming. Within four years, the company's structural products division will sell about $1 billion worth of frames, crossmembers and engine cradles, and 40% of those products will be hydroformed, reports Dana Vice President Michael Greene. Most of the jobs will be pickup and SUV frames.

Currently, the structural products division generates $870 million in annual sales, and only one product - the engine cradle for the new Ford Windstar minivan - is hydroformed.

Most hydroform presses, which use liquid under high pressure to shape metal into tubular-type shapes, are purchased in Europe. But Dana couldn't find a press long enough or agile enough to handle lengthy rails, so its engineers built their own and called it "Robo-Clamp." It applies 10,000 metric tons of pressure, while most hydroform presses apply only 5,000 metric tons.

Dana currently has one Robo-Clamp - at its structural products engineering center in Reading, PA - but the company expects to have as many as 12 in operation within five years, in three plants. Overall, the division will add five new plants by 2003, in Thailand, Brazil, Venezuela, Argentina and near Shreveport, LA.

Hydroforming offers significant advantages in process and weight savings. The hydroformed Windstar engine cradle, for instance, produced 20% gross weight savings over the stamped component it replaced. Scrappage also is usually reduced with hydroforming.

Within five years, Dana will produce an aluminum space frame with hydroformed components for a North American customer for a low-volume passenger car. The supplier also wants to pilot a "rolling space frame," a complete skeletal structure for a vehicle's lower and upper body.

Beyond hydroforming, Dana continues its research into magnetic pulse welding and recently received a patent for a process that joins steel to composites such as plastics.