As emission regulation of vehicles is being reinforced globally, the current requirement of the automobile industry are innovative green technologies that reduce the weight of the vehicle, thereby improving fuel consumption and the amount of exhaust gas emission. The application of ultra-high strength steel (UHSS) for vehicles has specifically been studied for light weight of vehicles. UHSS withstands greater loads than a general steel sheet of the same thickness. The spring-back and formability of the UHSS are also worse than general steel sheet due to their high elasticity and high yield strength. Various methods applied for processing UHSS include roll-forming and hot-press forming. However, these processes have not only high installation cost but also low productivity. This study therefore developed the cold-press forming method to overcome these disadvantages. The objective of this study is to determine the optimum conditions of the cold press required to form the upper seat track using UHSS. Forming analysis predicted the spring-back at each stage of the press forming. The prediction of spring-back was compared with the manufactured upper seat track by try-out, thereby reducing trial and error in the pressing process.

Recently, ball screws have been used in machine tools, robot parts, and medical instruments. The demand for ball screws of high precision and reduced size is increasing because of the growth of high value-added industries. Three types of ball screws are typically used: deflector type, end-cap type, and tube type. They are also classified from C0 to C9 according to the precision level. A deflector type ball screw can reduce the variation of rotational torque and the size of the nut of the ball screw is minimized. To ensure the reliable design of ball screws, it is important to perform a structural analysis. The purpose of this study is to perform a stability evaluation through analysis of a deflector type miniature ball screw for weapon systems. The analysis is performed through Finite Elements Method (FEM) simulation to predict characteristics such as deformation, stress, and thermal effects. The interference between the shaft and the deflector for smooth rotation are also studied. Based on the results of the analysis, the development of the deflector type miniature ball screw for weapon systems is performed.