The parking gear is very important part of automotive because it is related to safety. Nonlinear gear groove of parking gear is used to enlarge the contact area between parking gear and pawl. The die has been widely applied for many industrial parts such as machine, automotive and so on. The purpose of this study is to investigate the stability of upper and lower dies by using numerical analysis. As the results, the lower die was weaker than the upper die in this study, and the lower die showed that it should be used within 500ton in terms of safety factor. Further the most weak point of lower die was low location in front of gear. Its minimum value of safety factor was 0.578 in case of 4000ton of press load, therefore, this weak point was needed to be reinforced.

Hot forging is widely used to manufacture many industrial parts such as machine, automotive and so on. It is important to simulate the relations or characteristics between preform and die before designing the die. The purpose of this study is to investigate the forging characteristics of parking gear with nonlinear gear groove, thus the behaviors of preform can be predicted in advance and finally they can be applied to die design. As the results, since the distributions of high effective strain rate of parking gear were less than 3%, it was predicted that the manufacturing of parking gear with nonlinear gear groove might be possible. Furthermore it was observed that, in this study, the effective stress of bottom die was lower than that of top die.