| 摘要 |
Even in indirect spot welding where a spot welding electrode applies pressure to overlapping metal sheets from only one side to weld a portion whose opposite side is in an unsupported and hollow state, an indirect spot welding apparatus can accurately control a pressing force of the spot welding electrode and stably obtain a welded portion having a satisfactory strength. In the indirect spot welding apparatus, a lower limit in a stable pressing force region where the pressing force of the spot welding electrode against the metal sheets can be controlled within a tolerance of ±10% ranges from 70 N to 200 N and an upper limit in the stable pressing force region ranges from 800 N to 2000 N, and an overshoot OS(%) = (PL-AL)/AL x 100 of the pressing force occurring when the spot welding electrode is pressed against the metal sheets is controlled to be 10% or less. In the equation described above, PL represents a peak pressing force (N) in an overshoot range, and AL represents an average pressing force (N) applied by the electrode. |
