Development of a Refill Friction Stir Spot Welding System using opposed robots

The Friction Stir Spot Welding (FSSW), which is one of innovative solid-state joining methodologies based on the Friction Stir Welding, is a promising technology that can replace rivets and fasteners. Especially refill type of FSSW is expected for aircraft manufacturing due to impressive appearance quality, excellent tensile strength, cost reduction and weight saving.

For the FSSW including the Refill FSSW, applicable part size was limited by the size of the C-frame with the FSSW gun, even though aircraft parts are quite large. And in spite of the fact that aircraft parts are required high accuracy, automation / robotics is greatly desired in the modern aircraft manufacturing.

This study introduces new the Refill FSSW system with coordinated high rigidity two robots which stand facing each other for assuming jointing large parts including the skin, and describes the results of the recent preliminary works at KHI, especially the mechanical properties of the Refill FSSW applied to the materials of Skin / Stringer or Skin / Shear-tie.