In this study, the effect of slit length on the reduction of waste material was studied numerically. At the same time, the tightening axial force between steering shaft and asymmetry pinch yoke was also studied and compared. To achieve this study, the numerical simulation was performed by AFDEX commercial code. The slit length(Ls) of pinch yoke was increased from 25mm to 34mm by the steps with an interval of 3mm. AISI 1025 was applied for the source material of asymmetry pinch yoke. Amount of deformation was applied as much as 0.1mm for tightening the pinch bolt yoke and the steering gear shaft. It was revealed that the stress of steering shaft ear in XX-direction and YY-direction showed the highest value in 34mm and 31mm of slit length cases, respectively. The stress of ZZ-direction has the same value in all cases. The tightening stress between the asymmetry pinch yoke and the shaft of steering gear had the highest value in XY-direction. In additions, when slit length was increased by the steps with an interval of 3mm, the material was more wasted approximately as much as 0.844g. In conclusions, 31mm of lit length was the optimal length in aspect of the tightening stress and the waste material.

In this study, the effect of upper die type on the load characteristics of lower die and the wasted material was studied numerically. The different shapes(A-type, B-type, and C-type) of upper die were applied. Also finite element analysis method was applied for the analysis in each stage. The half of X, Y plane was analyzed due to the symmetrical shape in order to reduce the analysis time and be accurate results. The coefficient of friction was set to oil_cold conditions as refer to the system library. It was revealed that principal stress was the order in A, C, and B. A and B type have the highest value in 4 stage, and C type shows the highest value in 3 stage. In addition, Von mises stress were higher in order A, B, and C. A and B type have the highest in 4 stage, and C type shows to have about the same value in the 2 - 5 stage. The load was generally higher than C type. The load of C type was reduced in YY-direction at each stage without 2, 5, 6 stage.

In this study, the effect of upper die type on the load characteristics of lower die and the wasted material was studied numerically. The open and closed types of upper die were applied for each stage and the results are analyzed using a finite element analysis method. The half of x,y plane was analyzed due to the symmetrical shape in order to reduce the analysis time. The coefficient of friction was set to Soap_Cold conditions as refer to the analysis library. It was revealed that a lot of underfill portion was observed the open type in stage 4. As a result of the maximum and minimum values of the max principal stress, closed type case much receives compressive stress about 620MPa-2019MPa. In case of open type, The load was reduced in all direction at each stage

This paper carried out design in order to reduce the process of asymmetric pinch yoke, one of the important parts which transfer power to wheels through gearing box in automobile steering system. The purpose of the study is to reduce prime costs and strengthen competitiveness by designing the total 8 processes including the up-setting and forging process of the No. 1 as the forging process the current method of production. The process with die stress analysis by using the finite element method have been carried out through new optimal die design. As this study result, it is expected that die life can be secured as excellent material flow and caused by forming load. A prototype has been produced by basis of the analysis result and the reduction of the process was successful. As the unit price is lower than that of the current process, the competitiveness can be expected.