ntion with reference to the accompanying drawings, in which:FIGS. 1A and 1B are a front view and a right side view, respectively, showing an entire configuration of an arc welding robot system according to the present invention;FIGS. 2A and 2B are diagrams for illustrating demounting and mounting processes, respectively, of a tool tip member;FIGS. 3A and 3B are a side cross-sectional view and a to