2024 Volume 65 Issue 763 Pages 109-115
To reduce environmental burden, there is a need to reduce the weights of automobile bodies and materials used. Motor cases, the subject of this study, are formed by multistage drawing. The required minimum thicknesses of motor cases vary depending on the parts because of different required properties, including rigidity. Therefore, technologies to control thickness distribution, such as partial wall thickening and thinning, are effective in reducing the weight and amount of material used. In this study, we proposed the use of a forming method to increase the thickness of a body part of a motor case, which requires a large sheet thickness. We developed an axial force application method in which a compressive load is applied in the axial direction during multistage deep drawing. We also performed numerical analysis to clarify the limit of thickening. To this end, the thickening mechanism of the developed method and the effects of different factors on the limit of thickening were examined. The developed method enabled the reduction in the amount of material used by approximately 3% for a product examined in this study.
