The object of this study is to improve the straightness in tubular shaft production. Die bearings of 1, 2 and 3 were inserted onto the lower die, respectively. In this study, the tubular shafts at the stage 5 were modelled as the standard and error cases. The error case assumes the production error of raw material. The coefficient of friction was set to the Oil_Cold conditions as referring to the analysis library. In the results, the effective stress was observed homogeneously on the distribution at yoke top in standard case. However, the effective stress was observed on the distribution at long section of yoke in case of the raw material with error. The metal flow line was stretched straight in standard case. On the other hand, the metal flow line was bent in all of error cases. The biggest displacement occurred when only one die bearing was applied. The smallest displacement occurred when two die bearings were applied in lower die.

• 김홍근(Graduate school of Venture, Hoseo University) | Hong-Guen Kim
• 민세훈(Graduate school of Mechanical Engineering, Kongju National University) | Se-Hun Min
• 서현규(Division of Mechanical & Automotive Engineering, Kongju National University) | Hyun-Kyu Suh Corresponding Author