May, 01/M P & P, Metal - Working Production & Purchasing/ -- Theta Industries Ltd., Barrie, ON has developed a deep-draw stamping process to produce chassis components such as stainless steel engine mount parts from a single blank, reducing material cost and eliminating the need for welding two pieces together.

Combined savings of over 30% are achieved compared to the previous progressive die stamping methods that Theta has previously employed.

The fuel filler tube (left) and engine mount (right) are produced using the PTC combination link press.

Other formed automotive parts that have a complex shape, including a stainless steel fuel filler tube, are also being produced using this strategy, which combines a special link-drive press, transfer automation and unique tooling.

The engine mount, a cage-type configuration, is completed in 14 deep draw, stamp and form stations from a 200mm round blank, with a 600 ton combination link press designed and built by Press Technology Corp. (PTC), Cambridge, ON.

The press is equipped with a two-axis in-press transfer that moves the parts through the multiple stations along a 3.75m press bed. The transfer is also available with three-axis motion.

The link motion of the PTC press is the key to accomplishing the forming of stainless and other steel with a slow deep draw, while maintaining production speeds up to 30 strokes per minute (spm) and minimizing die wear.

On a PTC link press, ram speed is fast on both the approach (to the blank) and the return to the top, with a 50% slowdown during the forming part of the stroke for better material flow and improved die life. A 50% slowdown is uncommon among link presses; 30% is more typical.

"We couldn't have done this costeffectively without the PTC link press motion," says Theta Industries President Frank Gauder of the engine mount.

"This process is the first of its kind.. it allows us to complete the part in a single pass through the press. We do it in less steps, and there is no expensive welding operation needed to join the legs of the two halves of the part. Die resharpening costs are minimized, and our intricate tooling is protected by both the gentle forming strokes and out smooth -in-- process transfer," says Gauder.

Prototyping work on an automotive fuel filler tube has focused on eliminating an annealing process that would be used mid-way through the forming process.