プロジェクション溶接現象についての研究(第3報)

電源特性と適正入熱制御方式の関連性

抄録

Based on the previous work, the regions of welding conditions were roughly decided by the electrode force and the, weld current in the power sources of drooping characteristics with different no-load voltages such as 3.3V and 6.3V. The region of the suitable welding condition was estimated by taking account of the indentation and the tensile shear strength.
The indentation was found to be seriously affected by the initial splash during collapse of projection in the case of using the power source with no-load voltage of 6.3V and by the splash in the latter half weld time after collapse of projection in the case of using the power source with that of 3.3V. Especially the expulsive initial splash was responsible for the deformation of nugget shape, unstablity of tensile shear strength with a large amount of scatter and unstable failure of welds in the tear or the shear fracture at the rate about 50%. The tensile shear strength tended toward saturation immediately after the occurrence of the splash in the latter half weld time.
In order to suppress these splashes and overcome these faults of the weld, the up slope electrode force was adaptively introduced in the power source with no-load voltage of 3.3V and the up slope control in the weld current at the initial weld time was remarkably adaptable in the power source with no-load voltage of 6.3V.