Development of Aluminum Alloy Roller Type Valve Rocker Arm by Casting and Forging Technique

The following is a report on the process development and materials for rocker arms.

This process is called a “hybrid process” which combines a casting process for blanks and a forging process.

To obtain high durability, aluminum alloy was selected based on eutectic Al-Si adding Cu, Mg and Mn. As the fracture load is about 2 times higher than that of diecastings of the same shape, the mechanical properties have been remarkably improved by the “hybrid process.”

Presently, rocker arms are being produced by a mass production system, providing superior performance to the new cars of MAZDA.