Search Results

Electroimpact has recently produced a high-speed fuselage panel fastening machine which utilizes an all-electric, CNC-controlled squeeze process for rivet upset and bolt insertion. The machine is designed to fasten skin panels to stringers, shear ties, and other internal fuselage components. A high riveting rate of 15 rivets per minute was achieved on the first-generation E7000 machine. This rate includes drilling, insertion, and upset of headed fuselage rivets. The rivets are inserted by a roller screw-driven upper actuator, with rivet upset performed by a lower actuator driven by a high-load-capacity ball screw. The rivet upset process can be controlled using either position- or load-based feedback. The E7000 machine incorporates a number of systems to increase panel processing speed, improve final product quality, and minimize operator intervention.

Electroimpact and Lockheed Martin have developed an automated drilling and fastening system for C-130J aft fuselage panels. Numerous design and manufacturing challenges were addressed to incorporate the system into Lockheed Martin’s existing manufacturing paradigm and to adapt Electroimpact’s existing line of riveting machines for manufacture of these legacy aircraft parts. Challenges to automation included design of a very long yet sufficiently rigid and lightweight offset riveting anvil for fastening around deep circumferential frames, automated feeding of very short, “square” rivets in which the length is similar to the head diameter, creation of part programs and simulation models for legacy parts with no existing 3d manufacturing data, and crash protection for the aircraft part from machine collisions, given the uncertainties inherent in the model and the unique geometry of the aircraft parts.

Electroimpact has developed a system for drilling and fastening of cargo door structures which efficiently addresses many of the manufacturing challenges that such parts present. Challenges to door automation include 1) the presence of an inner skin that must be processed, in addition to the outer skin, and 2) a stiff frame structure, which makes the clamping and drilling processes that are typical to automated fastening machines very unforgiving of any errors in workpiece positioning. In this case, the manufacturing cell was to be installed in an existing facility with very limited ceiling height, further complicating the system and process design. New methods were devised to solve these problems, and the solutions found will likely have utility in future applications.