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The Automated Fiber Placement (AFP) machine layup run time in large scale AFP layup cells consumes approximately 30% of the entire part build time. Consequentially, further reductions to the run time of the AFP machine part programs result in small improvements to the overall cycle time. This document discusses how Electroimpact's integrated system and cell design reduces the overall cycle time by reducing the time spent on non-machine processes.

Boeing's wholly owned subsidiary in Australia, Hawker de Havilland produces all ailerons for the Boeing 737 family of aircraft. Increasing production rates required to meet market demand drove the requirements for a new updated approach to assembly of these parts. Using lean principals, a pulsed flow line approach was developed. A component of this new line is the integration of a flexible robotic drilling/trimming system. The new robotic system is required to meet aggressive tack time targets with high levels of reliability. The selected system was built on a Kuka KR360-2 conventional articulated arm robot. A significant challenge of this project was the requirement for the process head to work efficiently on an aileron in an existing jig. As a result a new side-mounted drill and trim end effector was developed. Automated tool changers for both cutters and pressure foot assemblies eliminated the requirement for in- process manual intervention.

Automated Fiber Placement (AFP) equipment has been developed capable of laying fiber in excess of 2000 inches per minute on full-size, complex parts. Two such high-speed machines will be installed for production of a nose section for a large twin-aisle commercial aircraft fuselage at Spirit AeroSystems in Wichita, Kansas along with a rotator for the fuselage mandrel. The problem of cutting and adding on the fly at these speeds requires thorough re-evaluation of all aspects of the technology, including the mechanical, controls, servos systems, and programming systems. Factors to be considered for high speed cut and add on the fly are discussed.

Electroimpact developed an end effector for Airbus UK, Ltd. for use on a Kuka KR350 robot provided by Airbus UK. The end effector is referred to as the DDEE (Drill and Drive End Effector), and incorporates four main functions. The end effector pushes up on a wing panel with programmable pressure, drills a hole with a servo-servo drill, inspects the hole with a servo ball-type hole gauge and then drives a pin-tail style lockbolt into the hole. The end effector is being used as part of a development and feasibility study for incorporating automation into the wing panel manufacture process.

Flex Track Drilling systems have been successfully implemented into several production environments and scenarios over the past couple of years. They continue to see a high demand where traditional machine tool implementations might be prohibitive due to cost or existing jig structures. This demand for innovation has led to a unique Flex Track design termed an Offset Flex Track that not only works between the vacuum rails, but can work beyond the envelope of the rails. This allows the machine to be used in situations such as the leading edge of wings where the vacuum rails cannot straddle the work envelope. The next evolution of this Offset machine is the introduction of final fastener installation onto the head using an onboard rivet gun. In addition, the camera used to locate datum points on the fuselage is now integrated into the nose piece, eliminating the need for a tool change to a spindle mounted camera.

A large free-standing structure is constructed to positively position the spar and related components in the major assembly jig of the wing for a military transport aircraft. The beam of this structure is mounted on mechanisms enabling the lateral retraction of the beam and tooling to provide full part loading access and extraction of a completed wing. The free-standing nature of this design also allows full integration of an automated drilling machine into the jig.

An automated machine has been designed with true offset fastening to join shear-tie/frame assemblies to the fuselage of the Boeing 787 Dreamliner. The machine can access fasteners located close to structural components that are very deep. This is accomplished by offsetting the fastening axis from the axis of the head for true offset fastening. The head can be positioned next to the structural component and the offset fastening tooling ‘reaches’ out to the fastener location (Figure 1). By using a true offset, the fastening machine can access fasteners that would be otherwise inaccessible by traditional automated equipment. The machine can also be lighter and more accurate when compared to fastening machines with traditional tooling.

British Aerospace, Airbus Ltd., Chester, UK manufactures the main wing box assembly for all current Airbus programs. Titanium interference fasteners are used in large numbers throughout these aircraft structures. On the lower wing skin of the A320 alone there are approximately 11,000 of this fastener type. Currently, the majority of these fasteners are manually installed using pneumatic or hydraulic tooling. British Aerospace engineers recognized the significant potential which automation offers to reduce these current labor intensive installation methods. Electroimpact proposed extending Low Voltage Electromagnetic Riveter (LVER) technology to the automatic installation of these interference fasteners as well as rivets. Close liaison between Airbus and Electroimpact engineers resulted in the development of an automated LVER based lockbolt installation system, which is currently undergoing evaluation.

Northrop Corporation manufactures body panels for the Boeing 747 aircraft. There are 1259 different stringer configurations used on the three 747 models with an average of 839 stringers per ship set. Until recently, all drain holes and skin coordination pilot holes were drilled manually using plastic application template tools (PATTS). Inventory costs were high and manual drilling errors led to excessive scrap and rework rates. Northrop engineers recognized that automating the stringer drilling process would produce higher quality parts at a lower cost. Northrop worked with Electroimpact, Inc. to develop the Automatic Stringer Drilling System (ASDS). The ASDS automatically clamps and drills all straight and contoured stringers used on the 747. Stringers are mounted on a rotating platform that provides +/- 90° of motion. Two servo-servo drills are mounted on a cantilevered arm with 25 feet of X-axis travel.

McDonnell Douglas Aircraft in St. Louis, MO manufacturers various transport and fighter military aircraft such as the C-17 and the F/A-18. With shrinking military budgets and increased competition, market forces demand high quality parts at lower cost and shorter lead times. Currently, a large number of different fastener types which include both solid rivets and interference bolts are used to fasten these assemblies. The majority of these fasteners are installed by hand or by using manually operated C-Frame riveters. MDA engineers recognized that in order to reach their goals they would be required to rethink all phases of the assembly system, which includes fastener selection, part fixturing and fastener installation methods. Phase 1 of this program is to identify and to develop fastener installation processes which will provide the required flexibility. The EMR fastening process provides this flexibility.

The A380 aircraft is the largest passenger aircraft ever built and an appropriate machine was required to accomplish the fastening of the wing plank to stringer and buttstrap joints. The lower wing panels are curved along the length and move 1.42m out of plane. All previous E4000 machines had clampup heads that would extend and retract whatever distance was required to contact the wing panel. To improve toolpoint alignment, Electroimpact added a Z-axis that moves the yoke in order to reduce the necessary travel envelope of the clamp table axes and to cause them to clamp in the same plane regardless of panel position along the Z-axis.

The Horizontal Automated Wing Drilling Equipment (HAWDE) machine is an enabling technology for automated drilling of large aircraft parts. HAWDE is a five axis drilling machine that operates over the upper and lower surfaces of eight wings, each more than 40 meters long and four stories tall. The machine accesses the entire A380 wing using a combination of elevators and a machine transporter that carries the machine from surface to surface. HAWDE drills holes in spars, butt splices, and rib feet in the wing box final assembly jigs for A380.

The Boeing 787 Dreamliner will be the most fuel-efficient airliner in the world when it enters service in 2008. To help achieve this, Boeing will utilize state-of-the-art carbon fiber for primary structures. Advanced manufacturing techniques and processes will be used in the assembly of large composite structures. Electroimpact has proposed a system utilizing the low recoil Low Voltage Electromagnetic Riveter (LVER) to drill and install bolts. A test program was initiated between Boeing Materials Process and Engineering (MP&E) and Electroimpact to validate the LVER process for swaging titanium collars on titanium pins in composite material. This paper details the results of these tests.

The Airbus A340-600 wing panel manufacturing system, which entered production in 1999, represents a major milestone for automated aircraft assembly. The new A340-600 system builds upon the success of the E4000 based A320 wing panel assembly system, which was introduced into production three years ago. The new A340-600 system consists of two 440 ft. assembly lines. One produces upper wing skin panels and the second produces lower skin panels. Each line consists of three fully automated CNC controlled flexible fixtures placed end to end serviced by two E4100 CNC assemble machines. Each fixture accepts multiple wing panels and can be automatically changed between the different configurations. Stringers are located and held using clamps mounted to “popping posts”. These posts automatically drop out of the machine path into the floor to provide clearance for complete stringer to skin fastening.

Robotic gripper technology has been integrated into CNC riveting machines. Handling fasteners efficiently is critical in automated wing panel riveting. Computer controlled rivet gripper and collar gripper technology has been developed that demonstrates high reliability and decreased fastener cycle times

As the aerospace industry moves toward determinate assembly and ever-tighter manufacturing tolerances, there is a need for automated, high-precision milling, trimming and drilling equipment that is specialized for aerospace applications. Precision countersinking is a common requirement for aircraft parts, but this is not a process that typical general-purpose milling machines are able to accommodate without the use of specialty tools such as depth-stop tool holders. To meet this need, Electroimpact has designed a 5-axis milling machine with high-speed clamping capability for countersink depth control. A custom trunnion and head with a quill and an additional clamp axis provide clamping functionality similar in speed and precision to a riveting machine, while maintaining the accuracy and features of a conventional machining center.