Manufacturing of Laminated Gear with Cold Die Forging Utilizing Divided Metal Flow (Plastic Forming Experiment with Different Materials)

The purpose of this study is to develop a new plastic forming process to fabricate a laminated spur gear that has two layers composed with the different materials in the radial direction. The whole processes are composed with a set of drawing-ironing process to form the pre-from for the outer material and die forging process to hold together two materials as a unit of a gear and simultaneously to form the outer gear tooth shape. The divided metal flow method in the die forging process was adapted to fill up the die cavity with the metal under the low working pressure condition. In the experimental simulation of the die forging process aluminum and copper were employed for the inner layer material and for the outer layer material of the laminated gear. The influence of the forging conditions on the working pressure and the metal filling up into the die cavity were quantitatively evaluated. As a result of the experiment the realization of the new process to fabricate the laminated spur gear was confirmed with the different materials.