Fork lifts with igm welding robots
For the manufacture of hydraulic cylinders, an automatic system consisting of a robot in a closed station with a transport and clamping device is used. Pipes with a diameter between 50 and 100 mm are machined. A library of preprogrammed processes permits a quick change to new workpiece types.
The length of the lift mast can be up to 6 m for large fork lifts. Due to the telescopic design, the masts are of different length and width, but have a similar structure within each family of parts. Thus to modify the robot programs, the igm offline program assembly system iPAT is used, permitting the shifting and copying of program steps or groups of steps on the PC. The geometric data can be read from the CAD system through an interface.
Especially the welding of forks benefits from the consistently high quality of the automation. Despite highly accurate preparation of the parts, the igm robots use a gas nozzle search for position detection and arc seam search to guide the torch along the seam. This is a significant factor in saving costs in the subsequent machining steps by practically eliminating rework.
Robot systems for the welding of the main frame consist of a 3-axis slide system and an L-shaped manipulator. This permits the workpieces always to be turned into the best position for access and welding. If the hydraulic and fuel tanks are integrated into the frame, seal welding permits them to be taken care of at the same time. The fasteners are then welded.
For extreme productivity requirements, automatic fabrication lines are available for main frames. These flexible manufacturing systems (FMS) are designed for the machining of a single workpiece type in multiple identical robot cells. The individual robot welding stations are connected by an automated transport system. The carriage moves on rails and carries a satellite carriage that can move into each station for loading, unloading, preparation and welding. The workpieces are automatically clamped by a special mechanism.
The welding of small components such as fork carriers, crossheads and carriages is carried out in compact robot cells with headstock manipulators or L-shaped manipulators with a load capacity of 150 kg. Rotary arms with suspended robots reduce downtime and permit the arrangement of multiple workstations in a single cell.