The Next Generation of Automated Hole Cold Expansion 1999-01-3437
In an effort to simplify and speed up manufacturing time for aircraft structure, a pure mechanical system has been developed by Fatigue Technology Inc. (FTI) to perform the Split Sleeve Cold Expansion (SsCx™) process to fastener holes. Historically, fastener holes requiring cold working for fatigue life enhancement are cold worked with a system which requires a manual hydraulic puller. This system works well and has been in place for more than 30 years.
This paper will discuss a new type of system that uses a simplified mechanical-only process that does not require hydraulic pneumatic or electrical systems. This new type of Automated Cold Expansion™ (AtCx™) puller unit has recently been fitted to an automated work cell that machines aircraft sub-components. This new cold expansion puller utilizes only simple rotary motion and converts it to a linear motion. The puller can be fitted to any kind of automated work cell, NC machine, or drilling and riveting equipment.
BF Goodrich Aerospace Aircraft Wheels and Brakes in Troy, Ohio, recently incorporated a mechanical AtCx puller in a new automated work cell that machines aircraft wheels. These aircraft wheels call out the FTI Split Sleeve Cold Expansion™ process to enhance the fatigue qualities of the wheel design. By incorporating the AtCx puller, BF Goodrich is able to perform the Cold Expansion (Cx) process faster and safer. A description of the installed puller and its operation will be presented.
The use of Cx technology in aircraft structure has been used for over 30 years to enhance the fatigue resistance of structure and structural components. Cold expansion technology can also allow a weight savings by permitting the structure to operate at higher stress levels while retaining good fatigue qualities. By facilitating a more widespread use of cold expansion technology in automated milling/assembly equipment, this new automated puller will ensure faster production while achieving higher quality designs with enhanced fatigue properties and potential weight reductions.