Abstract: An automobile side panel with a space defined therein is welded by positioning a plurality of outer panel components with a plurality of first clamping mechanisms, welding the positioned outer panel components into an outer side panel member, positioning an inner side panel member in superposed relation to the outer side panel member with a plurality of second clamping mechanisms, and welding the positioned outer and inner side panel members into a side panel, with the space defined between the outer and inner side panel members. The outer panel components and the outer and inner side panel members are welded in one welding station.

Abstract: A working line for performing certain operations on a side panel for a motorcar including, in order, a set station, a welding station, and a sealing station. A set carrier is reciprocatable on a first railway between the set station and the welding station and carries a set jig on which the side panel components are loadable in a standing posture. Holding members and welding robots are provided on one lateral side of the welding station to receive the side panel, hold it in place, and weld it, all in a standing posture. A discharging carrier is reciprocatable between the welding station and the sealing station on a second railway offset sideways in relation to the first railway and carries a discharging jig for receiving the welded side panel and conveying it in its standing posture to the sealing station. A sealing jig and a sealing agent application robot are disposed at the sealing station opposite one to another on both sides of the second railway.

Abstract: Apparatus for assembling a motorcar body from the component parts of a floor panel, a roof panel and side panels. A set carrier can reciprocate between a setting station and a welding station having a welding jig mechanism including welders. The set carrier has floor panel holding members for positioning and holding the floor panel and side panel holding members for pressing the side panels against and fixing the side panels to the floor panel, with the roof panel solely being held between receiving upper edges of the side panels. The thus-formed and held predetermined car body framework is conveyed to the welding station on the set carrier and is there transferred as-is to the welding jig mechanism to be welded.

Abstract: An exchanging apparatus for exchanging welding jig units of an automatic welding apparatus on an assembly line. The automatic welding apparatus includes a combining station where a work to be assembled is combined and welded by detachable welding jig units, and a set carrier for moving the work along a conveying railway to and from the combining station. The exchanging apparatus comprises an exchanging railway which crosses the conveying railway through a switch mechanism and at least two exchanging carriers, each having thereon a gripping means for gripping a welding jig unit. Each of the above carriers is mounted on a plurality of wheels, each of which is turnable about a fixed vertical shaft on the respective carrier.