1. Field
Embodiments of the disclosure relate generally to the field of manufacturing of aircraft subassemblies and more particularly to embodiments for high rate pulsing of an assembly line through multiple positions employing interchangeable automated guide vehicles with task specific headers for transfer to multi-access position systems for subassembly support at each position for determinant assembly.
2. Background
Existing Aircraft wings are assembled in a vertical orientation and are held in large floor mounted assembly fixtures that control the location of the major components until they are fastened together and become sufficiently stable. Wings are then transported with overhead building cranes and placed in a horizontal orientation in a lay down fixture or dolly to continue the assembly process. Mechanics and their tools are transported between floors of scaffolding and between the multiple rate fixtures. Operations are batch processed and drilling and installation of the thousands of high tolerance fasteners are done manually. They use large expensive dock assembly systems that are not capable of pulsing the wing to specialized assembly stations. They all use overhead building cranes that require specialized crews to attach and move the wing. They also require a “high bay” (40′-75′ high) facility. The time to move as well as scheduling delays makes this approach impractical for a takt time paced assembly line.
Recurring labor associated with existing production systems can be thirty expensive and requires non-value added time for rotating the wing, setting up the portable drilling equipment and removing, deburring and reinstalling the lower panel. Additionally, it is not possible to use “C” frame or Yoke automatic fastening systems on closed wing structure such as a wing box with both panels attached. Manual drilling and fastening which is therefore required may have undesirable ergonomic and quality issues.
Prior art practice for production of aircraft wing assembly uses large floor mounted “end gate” castings at multiple dock or stationary locations to clamp and hold the various sub-assemblies together until they are drilled, disassembled, deburred, reassembled and permanently fastened. These multi-ton large weldments or cast tools which locate the side of body components together are expensive and impractical to move through a horizontal pulsing assembly line.
Existing production assembly systems for aircraft wing moving lines rotate the wing so that the upper and lower panel drilling is done manually or via portable semi-automated drilling systems from above the wing. In traditional monument based vertical assembly systems wings are drilled and countersunk manually or with portable equipment that is moved from fixture to fixture. Both systems require the panel to be removed and debuted and then reassembled. Existing systems that do not require disassembly and deburring must employ large “C” frame or Yoke riveters that work on part that have access on both sides.
It is therefore desirable to provide horizontal pulsing assembly lines with automated transport systems for a partially assembled wing and automated systems to drill and install fasteners for the main wing box of commercial airplanes. It is further desirable that the transport system be reconfigurable for right hand and left hand wings as well as be segmented to provide a smaller storage footprint and allow mechanics access to temporarily secure the lower panel to the wing box. It is also desirable that the transport system load the lower panel from under the wing box.
If is additionally desirable that the side of body geometry be located and held in configuration as it progresses through the different assembly positions until it is fully fastened without the use of large heavy traditional tooling.
A single piece pulsed flow wing assembly method providing for horizontal wing manufacture uses synchronized automated vehicles guided in a predetermined manner to move and, locate wing structure in a plurality of assembly positions. Multi-axis assembly positioning systems (MAPS) are used at each assembly position to support and index components in the wing structure and determinant assembly techniques are used for indexing of the components. Modular automated manufacturing processes employing magnetic assembly clamping, drilling, fastener insertion, and sealant application are employed.
Exemplary embodiments provide a method and apparatus wherein determinant assembly of an aircraft structure is accomplished in three assembly positions with loading a front spar with attached mechanical equipment interface fittings (MEs) and a rear spar with attached MEs onto multiple front and rear Multi-Axis Positioning Systems (MAPS) of a first assembly position. The MAPS supporting the front spar in 3 axes are then adjusted to place the front spar in a wing reference frame and ribs are stacked on the front and rear spars. The ribs are attached to the front spar and the MAPS supporting the rear spar are adjusted to align determinant assembly (DA) holes in the ribs and rear spar for proper positioning in the wing reference frame. Fasteners are then installed to secure the ladder assembly of the wing structure.
At predetermined assembly points, a planar laser is used to determine relative displacement from the wing reference frame of defined measurement points on the wing structure assembly due to flexing of the assembly and tooling resulting from addition of mass to the assembly. The MAPS are then adjusted to bring the measurement points back into wing reference frame position.
In an exemplary embodiment, a wing side of body geometry tool is installed as a dummy rib and the tool is pinned to the spar terminal fittings. The forward web and aft web are installed and accurately located to the front spar and rear spar with DA holes in common to the spar terminal fittings. The upper panel is loaded onto the ribs and flexed by pushers mounted on the applied tool until the DA holes in the webs and chords are aligned. Temporary fasteners are then installed.
Movement of the wing structure between assembly positions is accomplished by mounting location specific headers on identical AGVs for inner and outer wing structure support with left and right wing designations. The header type sensed and each AGV is synchronously controlled based on header type.
For continued processing, the AGVs are positioned under the wing structure as supported in the MAPS of the first position. The headers are raised with point support mechanisms controllable in multiple axes to engage the wing structure. The MEs are released from the MAPS in the first position and retracted. The AGVs supporting the wing structure are then synchronously moved to a second assembly position. In one exemplary configuration, prior to releasing the MEs, load cells in the point support mechanisms and fixture receivers are used to confirm that load of the wing structure is being borne by the AGV headers.
For continued assembly, the headers on the AGVs are positioned for engagement of the MEs attached to the wing structure with the fixture receivers of a plurality of MAPS in a second assembly position. The MAPS in the second assembly position are extended to engage ME headers with fixture receivers in the MAPS and the fixture receivers are clamped to the ME headers. The AGV headers are then withdrawn. The planar laser is then employed again to determine relative displacement from the wing reference frame of the defined measurement points on the wing assembly and the MAPS are adjusted to bring the measurement points back into wing reference frame position.
The lower wing panel is then loaded onto the header assemblies of the AGV pair and synchronously moved with the AGVs to position the lower wing panel under the wing structure supported in the MAPS in the second assembly position. The combined headers and the AGVs are controlled to accomplish a synchronized multi-axis coordinated motion to insert the lower skin into position on the wing structure aligning DA holes in the lower skin panel with spar fitting attachment points. The lower skin panel is then urged against the wing structure using the support point mechanisms for firm engagement with the wing structure. Press up forces of the panel to the main wing box structure are monitored using the load cells to assure that excessive forces are not used and if force limits are exceeded audible and visual alarms are set off and motion of the AGVs and associated fixtures is stopped. The lower skin panel is then flexed using the pushers on the wing side of body tool until DA holes in the forward and aft web are aligned with corresponding DA holes in the lower panel cord to set the contour. The lower wing panel is sealed and permanent tack fasteners are installed. The AGV headers are then adjusted to assume the wing structure load and the MEs are released from the MAPS in the second assembly position. The MAPS are retracted and the wing structure is synchronously moved with the AGVs to a third assembly position.
A plurality of MAPS are suspended from a positioning truss mounted to a Floor Mounted Universal Holding Fixture (FUHF). The headers on the AGVs are positioned for engagement of the MEs on the wing structure with the fixture receivers of the MAPS in the third assembly position. The MAPS are extended to engage the ME headers with the fixture receivers and the fixture receivers are clamped on the ME headers. The AGV headers are then withdrawn.
The planar laser may again be used to determine relative displacement from the reference frame of defined measurement points on the wing structure assembly and the MAPS adjusted in the third assembly position to bring the measurement points back into wing reference frame position.
Multiple Automated Wing Fastener Installation Systems (AWFIS) are provided and brought into operating position on positioning guideways under the FUHF. The surface of the lower wing panel is contacted with the automated fastening head on each AFWIS from the outside of the wing structure. Upward force is provided by the head in conjunction with an electromagnet energized to create an electromagnetic field pulling a steel backing plate inside the wing structure to provide sufficient clamping force to close any gaps between the structure. The AFWIS systems each accomplish drilling, countersinking, applying sealant and inserting ho km into the lower wing panel and ribs or spars with the head.
The wing structure is then dihedrally canted with the MAPS actuators and the wing structure is lowered onto a transfer dolly. The MEs are released from the MAPS and the MAPS are retracted. The transfer dolly is then pulsed to the next assembly position for the aircraft.
The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present invention or may be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings.
The embodiments described herein employ determinant assembly (DA) techniques to assemble exemplary main wing components, thereby allowing the assembly fixtures to be smaller and more flexible. The system is a single piece flow, takt time paced pulsing assembly line that moves the wings to positions where mechanics and automated machines perform specialized work. The embodiments described may be mirrored for two linear assembly lines (right and left hand) that have three specialized assembly stations where the mechanics have tools that are optimized to perform efficient location (using determinant assembly features such as surfaces and coordination holes), drilling and fastening operations to the ribs, spars, panels and various structural fittings. The holding fixtures at each position are programmable and retract to provide clearance for the wing moves and to allow compensation for tooling deflection and tooling inaccuracies. A planar locating laser system measures key targets of the wing and communicates the inaccuracies to a fixture controller which adjusts the holding fixtures until the errors are eliminated. When the takt time clock reaches 0, the partially assembled wings automatically pulse to the next position using two electronically synchronized AGVs that are not physically connected. In Position 1 initial assembly of wing structure front spars, ribs and the upper panel is accomplished. In Position 2 the lower panel is loaded automatically via the AGVs and is located to the ladder structure via DA holes. The panel is sealed, permanent tack fasteners are installed and the wing is transported to Position 3 were it is held from above. In position 3 a one sided automated system is used to electromagnetically clamp-up the lower wing panel to spar or ribs, drill and countersink, install sealant, insert interference fit bolts. The side of body webs are fastened while the side of body panel fittings and spar terminal fittings are held in engineering configuration by a small light weight tool that uses a combination of determinant assembly holes in the chords, web and terminal fittings as well as an applied tool that acts as a dummy rib to set the distance and angularity between the front and rear spar terminal fittings. Mechanics can work concurrently on the wing with the automated fastening machines once a zone is completed and vacated. Once the wing is fastened it is lowered onto a wheeled cart, is pulsed out of position 3 and continues down the associated aircraft assembly line. The wing can be pulsed or can continually move down the assembly line as major fittings as well as leading and tailing edge components are installed to the wing box.
Referring to the drawings,
The fixture receiver 40 on each MAPS provides an interface to support a mechanical equipment (ME) interface tool 42. For the embodiment shown in greater detail in
Returning to
As components are added to the wing assembly potentially resulting in deflection of the components and tooling due to the added mass, a planar locating laser 65 positioned below the wing at front and rear spar locations is employed to located defined reference points on the structure as defined in application Ser. No. 12/550,666 filed on Aug. 31, 2009 now U.S. Pat. No. 8,539,658 entitled Autonomous Carrier For Continuously Moving Wing Assembly Line having a common assignee with the present application the disclosure of which is incorporated herein by reference.
The MAPS 16 are then adjusted to compensate for the deflection to allow accurate assembly of subsequent components in the structure. The laser locating process is employed multiple times to assure continued conformity to the wing reference frame. Determinant assembly using the motion capability of the MAPS precludes the need for massive and expensive rigid tooling to maintain.
Upon completion of assembly steps in position 1 at the defined takt time, a pair of Automated Guide Vehicles (AGV) 64, 66, shown in
Each support point mechanism 76 employs a vacuum chuck support pad 80 to support the wing structure elements at various handling points as described. Each header incorporates a bunion fitting 82 for rotating and placing the wing lower skin from an overhead crane to the headers. The support point mechanisms in each header and the fixture receivers in the MAPS incorporate load cells for determining weight bearing of the wing structure by the MAPS or the AGVs during transfer. As the wing assembly is lowered by the MAPS load cells in both the AGVs and the fixture receivers verify that the wing load has been transferred to the fixture before the AGVs retract and move away from the wing to return to their parking position. The load cells are also used to verify that the AGV has received the wing structure from the fixture receivers before it begins the transfer to the next assembly position/fixture.
Once the assembly operations are complete for position 3 the wing structure is canted dihedrally by the MAPS and lowered onto a transfer dolly. The transfer dolly then pulses to the next assembly position for the aircraft.
As represented in
Identical AGVs have location specific headers mounted for inner and outer wing structure support with lei and right wing designations, step 1224. The AGV computer control systems sense the header type and synchronously control the AGV based on header type, step 1226. The AGVs position under the wing structure as supported in the MAPS of position 1, the headers, with point support mechanisms controllable in multiple axes are raised to engaged the wing structure, step 1228. When the load cells in the point support mechanisms and fixture receivers confirm that load of the wing structure is being borne by the AGV headers, the MEs are released from the MAPS in position 1, step 1230, the MAPS 3-axis motion assemblies retract, step 1232 and the AGVs synchronously move the wing structure to position 2, step 1234. The headers on the AGVs position the wing structure for engagement of the MEs with the fixture receivers of the MAPS in position 2, step 1236. The MAPS 3-axis motion assemblies in position 2 extend to engage the ME headers with the fixture receivers, step 1238. The fixture receivers clamp the ME headers and the AGV headers are withdrawn, step 1240. The planar laser determines relative displacement from the wing reference frame of defined measurement points on the wing assembly, step 1242. The MAPS 3-axis motion assemblies are then adjusted to bring the measurement points back into wing reference frame position, step 1244.
The lower wing panel is loaded onto the header assemblies of the AGV pair, step 1246 and the AGVs synchronously move to position the lower wing panel under the wing structure supported in the MAPS of position 2, step 1248. The combined headers and the AGVs then accomplish a synchronized multi-axis coordinated motion to insert the lower skin into position on the wing structure aligning DA holes in the lower skin panel with spar attachment points, step 1250. The lower skin panel is then loaded using the support point mechanisms for firm engagement with the wing structure, step 1252. Monitoring of press up forces of the panel to the main wing box structure is accomplished using the load cells to assure that excessive forces are not used and if force limits are exceeded set off audible and visual alarms and stop the motion of the AGVs and associated fixtures 1254. The lower skin panel is flexed using the pushers on the wing side of body tool until DA holes in the forward and aft web are aligned with corresponding DA holes in the lower panel cord to set the contour, step 1256. The lower wing panel is then sealed and permanent tack fasteners are installed, step 1258.
The AGV headers are then adjusted and the MEs are released from the MAPS in position 2, step 1260, the MAPS 3-axis motion assemblies retract, step 1262 and the AGVs synchronously move the wing structure to position 3, step 1264. The headers on the AGVs position the wing structure for engagement of the MEs with the fixture receivers of the MAPS in position 3, step 1266. The MAPS 3-axis motion assemblies in position 3 extend to engage the ME headers with the fixture receivers, step 1268. The fixture receivers clamp the ME headers and the AGV headers are withdrawn, step 1270. The planar laser determines relative displacement from the wing reference frame of defined measurement points on the wing assembly, step 1272. The MAPS 3-axis motion assemblies are then adjusted to bring the measurement points back into wing reference frame position, step 1274.
Multiple Automated Wing Fastener installation Systems (AWFIS) are brought into operating position on positioning guideways, step 1276. The automated fastening head contacts the surface of the lower wing panel from the outside of the wing structure and applies upward force in conjunction with the electromagnet that is energized and creates an electromagnetic field that pulls a steel backing plate from the inside of the wing to provide sufficient clamping force to close any gaps between the structure, step 1278. The head drills, countersinks, applies sealant and inserts bolts into the lower wing panel and ribs or spars, step 1280. Once the assembly operations are complete for position 3 the wing structure is canted dihedrally with the Position 3 MAPS, step 1282 and lowered onto a transfer dolly, step 1284. The MEs are released from the MAPS in position 3, step 1286, the MAPS 3-axis motion assemblies retract, step 1288. The transfer dolly then pulses to the next assembly position for the aircraft, step 1290.
Having now described various embodiments of the invention in detail as required by the patent statutes, those skilled in the art will recognize modifications and substitutions to the specific embodiments disclosed herein. Such modifications are within the scope and intent of the present invention as defined in the following claims.
This application is a continuation-in-part of application Ser. No. 12/691,307 filed on Sep. 10, 2013 entitled HIGH RATE PULSING WING ASSEMBLY LINE having a common assignee with the present application, the disclosure of which is incorporated herein by reference as though fully set forth.
Number | Date | Country | |
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Parent | 12691307 | Jan 2010 | US |
Child | 14183034 | US |