A plastic welding device for the automatic welding of at least three components comprises at least one first tool, at least one second tool and at least one transfer device. A first component is positionable on the first tool. The first and the second tool are movable relative to each other in order to weld the first component with a second component. The transfer device is movable relative to at least one of the tools and with it at least one third component is automatically feedable to one of the tools. In this manner, the at least one third component is weldable with the compound made up of the first and second components via the first and the second tool or via the first or the second tool in combination with the third tool.