| 摘要 |
PROBLEM TO BE SOLVED: To provide a spot welding apparatus capable of obtaining the consistent welding quality when executing the spot welding of a member to be welded in which a thin plate is superposed on two thick plates.SOLUTION: When executing the spot welding of a member 100 to be welded in which a thin plate 101, a first thick plate 102 and a second thick plate 103 are successively superposed on each other, the member 100 to be welded is held and pressurized by a fixed side electrode 104 which is abutted on the second thick plate 102, a movable side electrode 17 which is abutted on the thin plate 101, and a welded member holder 26 of a control pressurizing means 20 which is adjacent to the movable side electrode 17 and abutted on the thin plate 101. The pressure by the fixed side electrode 14 is applied to the second thick plate 103, the pressure by the movable side electrode 17 and the control pressure by a control pressure applying means 20 are applied to the thin plate 101 side, and the pressure by the fixed side electrode 14 is controlled to be smaller than the pressure by the movable side electrode 17. The current density between the thin plate 101 and the first thick plate 102 becomes high, excellent nuggets are formed from the thin plate 101 to the second thick plate 103, and thereby, the welding quality is improved. |
