Patent ID: 8993918
Filing Date: 2015-03-31
Classification: B23K

Abstract:
1. A spot-welding device for spot-welding a workpiece that includes a thin plate, a first thick plate, and a second thick plate that are sequentially stacked, the first thick plate and the second thick plate being thicker than the thin plate, the spot-welding device comprising: a base; a first welding electrode configured to face the second thick plate; a second welding electrode that is coaxially aligned with the first welding electrode and configured to face the thin plate of the workpiece so as to clamp and press the workpiece together with the first welding electrode; a control-pressure applying unit including: a control-pressure actuator that is attached to the base, the control-pressure actuator being capable of moving the first control presser and the second control presser selectively between a first pressing position and a second pressing position, the first pressing position being where the second control presser is located away from the thin plate and where the first control presser is set adjacent to the first welding electrode and is brought into contact with the second thick plate so as to apply the first control pressure to the second thick plate, the second pressing position being where the first control presser is located away from the second thick plate and where the second control presser is set adjacent to the second welding electrode and is brought into contact with the thin plate so as to apply the second control pressure to the thin plate; and a pressure actuator that is attached to the base and supports the second welding electrode via a rod, the pressure actuator being capable of moving the second welding electrode between a retreated position located away from the workpiece and a pressing position where the second welding electrode is brought into contact with the thin plate so as to clamp the workpiece together with the first welding electrode and to apply pressure onto the workpiece, wherein the workpiece is clamped and pressed by the first welding electrode and the first control presser that are brought into contact with the second thick plate, and by the second welding electrode that faces the first welding electrode is brought into contact with the thin plate, wherein the workpiece is spot-welded by applying electricity between the second welding electrode and the first welding electrode in the state where the workpiece is clamped and pressed, wherein the workpiece is clamped and pressed by the first welding electrode that is brought into contact with the second thick plate, the second welding electrode, and the second control presser that face the first welding electrode are brought into contact with the thin plate, and wherein the workpiece is spot-welded by applying electricity between the second welding electrode and the first welding electrode in the state where the workpiece is clamped and pressed.