A study on process design of plate cold forging for machinability improvement of piston under drive brake

Reduction of energy in manufacturing industries is a current issue to keep the earth green. This energy saving yields the cost reduction in automotive industries. Many automotive part companies try to improve their manufacturing process to save the manufacturing energy. Specially, many attempts on changing the hot forging process into the cold forging process of plate forging have been tackled in the piston under drive brake used in an automotive transmission module. The turning process after hot forging changed to turning after plate cold forging for the energy and cost reduction. But two extrusion shapes in an outermost diameter of part let fall tool life by interrupted cut in turning. Therefore, it needs thickness reduction of two extrusion areas in the outermost diameter. This study suggests an effective way to reduce the thickness of interrupted cut in forging stage.