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Viewing 1 to 30 of 227
2016-09-27
Technical Paper
2016-01-2089
Jose Guerra cEng, Miguel Angel Castillo
Abstract Aernnova experience on automatic drilling operations started in 1,999. The company signed a new contract with Embraer, to design, manufacture and assembly several structures of the model 170. It was big news for the company. But after that minute of pride, manufacturing engineering people of the company started to think about the process to assemble those big panels of the Horizontal Stabilizer, Vertical Stabilizer and Rear Fuselages in the best Quality and Cost. There were a lot of rows of rivets to install. Some ideas arisen, but the final decision was to forget the available processes at that time and think about to automate the drilling, countersink and riveting of the stringers, doublers and window frames to the panels. There were a lot of doubts, figures to do and obstacles, but the company took the decision of going ahead with that process. That step changed the state of the art at that time in the company.
2016-09-27
Technical Paper
2016-01-2091
Raul Cano, Oscar Ibanez de Garayo, Miguel Angel Castillo, Ricardo Marin, Hector Ascorbe, Jose Ramon de los Santos
Abstract The aim of this paper is to present a robust and low-cost automatic system for drilling aluminum stacks, as well as an integral methodology for the design of tool trajectories and the control of the drilling process itself. The proposed system employs a high accuracy robotic arm, a commercial spindle head and a specially developed SCADA, which enables it to load tool trajectories designed by using any software application. Furthermore, this SCADA is useful to monitor the main parameters of the drilling process for anticipating problems related to the unexpected tool wear or for a quick response in case of tool collision. A special jig for positioning the stack to be drilled is designed to increase the robot accessibility. In this work, tests are performed for optimizing the cutting parameters of the robotic system in order to maximize the accuracy and the surface finishing of the holes.
2016-09-27
Technical Paper
2016-01-2096
Simon Schnieders, Dirk Eickhorst
Abstract Drilling of high-strength titan material and composites in combination creates complex challenges in order to achieve required productivity and quality. Long spiral chips are characteristically for the titan drilling process, which leads to e.g. chip accumulation, high thermomechanical load, surface damages and excessive tool wear. The basic approach is the substitution of today’s peck drilling as current solution to this problem and the implementation of a vibration assisted drilling, so called micro-peck-drilling-process, to generate a kinematic chip breakage in a significant more efficient way. To meet perfectly the requirements regarding rates, quality and automation level, Broetje-Automation as system integrator has investigated and developed the implementation of different alternative high-performance systems and methods to approach the optimal oscillation movement of the tool.
2016-09-27
Technical Paper
2016-01-2095
Agata Suwala, Lucy Agyepong, Andrew Silcox
Abstract Reduction of overall drag to improve aircraft performance has always been one of the goals for aircraft manufacturers. One of the key contributors to decreasing drag is achieving laminar flow on a large proportion of the wing. Laminar flow requires parts to be manufactured and assembled within tighter tolerance bands than current build processes. Drilling of aircraft wings to the tolerances demanded by laminar flow requires machines with the stiffness and accuracy of a CNC machine while having the flexibility and envelope of an articulated arm. This paper describes the development and evaluation of high accuracy automated processes to enable the assembly of a one-off innovative laminar flow wing concept. This project is a continuation of a previously published SAE paper related to the development of advanced thermally stable and lightweight assembly fixture required to maintain laminar flow tolerances.
2016-09-27
Technical Paper
2016-01-2097
Sylvain Laporte, Cosme De Castelbajac, Mathieu Ladonne
Abstract The Vibration Assisted Drilling (VAD) process has been implemented in Automated Drilling Equipment (ADE) on an industrial scale since 2011. Today more than 11000 ADEs are currently used on aircraft assembly lines. As well as drawing up a short report on the use of this new process, the authors make an assessment on new challenges that VAD has to face up. Indeed production rates are increasing and ADE manufacturers improve their technologies, one of the most recent and major development concerning the electrical motorization of the machines. These evolutions are as many opportunities for the VAD provided you have a clever understanding as well as an expert knowledge of the process. Thus the authors propose a new dynamic model of the whole VAD system which integrates the behavior of the part, cutting tool/material pair and the machine. The confrontation of model results and experimental validation tests demonstrates the relevance of the works.
2016-09-27
Technical Paper
2016-01-2101
Burak Deger, Fazli Melemez, Aykut Kibar lng
Abstract A hybrid drilling process of multi material stacks with one shot drilling recently emerge as an economical and time efficient method in aerospace industry. Even though the comprehensive experience and knowledge is available for the cutting parameters of composites and metals alone, significant gap exist for the hybrid drilling parameters. Determination of these parameters such as feed rate, spindle speed and pecking depth has vital importance so as to provide a robust and optimal process to ensure dimensionally high quality, burr and delamination free holes. Main challenge of hybrid drilling operation is to obtain required hole diameter with adequate homogeneity and repeatability. In this study, effect of cutting parameters on dimensional hole quality was investigated. In addition to the hole diameter tolerances, CFRP hole enlargement phenomena which is encountered as a specific drawback of metal-exit stack configurations is also addressed within the scope of this study.
2016-09-27
Technical Paper
2016-01-2099
Peter Mueller-Hummel, Thomas Langhorst
Abstract On CNC Machines, drilling holes under perfect condition is possible. For drilling holes into titanium, composite and aluminum stacked materials the specific cutting condition can be selected. Furthermore surrounding conditions such as peck cycle, MQL and force and torque monitoring can be easily adapted. When drilling holes in the final assembly, CNC machine tools cannot be employed due to sizes and accessibility. Power Feed Units or Automated Drill Units ADUs are very handy, flexible and depending upon the jig extremely rigid. Whenever a machine tool does not fit, ADUs are highly recommended. In comparison to machine tools, conventional pneumatic ADUs can be used with one fixed set of feed, speed and micro peck only. Due to that a compromise in cutting condition has to be chosen in drilling stacked material with different layers.
2016-09-27
Journal Article
2016-01-2116
Peter Mueller-Hummel
Abstract Drilling holes into metal with MQL (Minimal Quantity Lubrication) is a normal procedure, because the drill is designed for drilling metal and the malleable capability of the metal compensates for the insufficient cutting capability of a worn out drill. Drilling composite materials using the same drill (designed for drilling metal) is a different procedure, because composite fibers are not malleable like metal at all. Due to this fact the tools become very hot trying to forge composite fibers like metal. The elastic behavior of the composite and the delamination inside the hole makes the tool temporary smaller than the diameter of the drill. The hole in the metal part of the stack remains slightly larger due to the heat and the thermal expansion rate. This paper shows how to drill metal and composite with the same diameter, so that achieving H8 quality is no longer a dream.
2016-09-27
Journal Article
2016-01-2126
Ali Mohamed Abdelhafeez, Sein Leung Soo, David Aspinwall, Anthony Dowson, Dick Arnold
Abstract Despite the increasing use of carbon fibre reinforced plastic (CFRP) composites, titanium and aluminium alloys still constitute a significant proportion of modern civil aircraft structures, which are primarily assembled via mechanical joining techniques. Drilling of fastening holes is therefore a critical operation, which has to meet stringent geometric tolerance and integrity criteria. The paper details the development of a three-dimensional (3D) finite element (FE) model for drilling aerospace grade aluminium (AA7010-T7451 and AA2024-T351) and titanium (Ti-6Al-4V) alloys. The FE simulation employed a Coupled Eulerian Lagrangian (CEL) technique. The cutting tool was modelled according to a Lagrangian formulation in which the mesh follows the material displacement while the workpiece was represented by a non-translating and material deformation independent Eulerian mesh.
2016-09-27
Technical Paper
2016-01-2136
Oliver Pecat, Tebbe Paulsen, Philipp Katthöfer, Ekkard Brinksmeier, Sascha Fangmann
Abstract Insufficient chip extraction often leads to disruptions of automated drilling processes and will have a negative impact on the surface qualities. One opportunity to avoid chip accumulation is based on a kinematically enforced chip breakage caused by sinusoidal axial oscillations of the drilling tool. Recent investigations have shown that the quality of chip extraction is, amongst others, considerably depending on the chip shape and mass which are defined by the cutting parameters feed, amplitude and frequency. So far only mechanical systems in the form of tool holders have been available on the market, which are restricted to a fixed frequency (oscillation frequency is coupled to the spindle speed). In the present study a spindle with magnetic bearings was used which allows to adjust the oscillation frequency independent of the spindle speed and therefore enables all opportunities to affect the generated chip shapes.
2015-09-15
Technical Paper
2015-01-2510
Ryan Haldimann
Abstract Accurate measurement of countersinks in curved parts has always been a challenge. The countersink reference is defined relative to the panel surface which includes some degree of curvature. This curvature thus makes accurate measurements very difficult using both contact and 2D non-contact measurements. By utilizing structured light 3D vision technologies, the ability to very accurately measure a countersink to small tolerances can be achieved. By knowing the pose of the camera and projector, triangulation can be used to calculate the distance to thousands of points on the panel and countersink surface. The plane of the panel is then calculated using Random Sample Consensus (RANSAC) method from the dataset of points which can be adjusted to account for panel curvatures. The countersink is then found using a similar RANSAC method.
2015-09-15
Technical Paper
2015-01-2513
Hans-Juergen Borchers, Kadir Akkuş, Cagatay Ucar
Abstract This paper will discuss the process of drilling large diameter holes within high quality requirements using a Robot positioning concept. This Robot end-effector system provides flexibility to handle different aircraft sections due to its Robot arm design. The material configuration that will be discussed in this paper is a mixed material stack of CFRP and Aluminum. The diameter range is from 7.9 mm to 15.9mm. This paper will focus on the largest diameter (Ø15.9mm). It addresses the process forces to be handled and the solutions. This paper will take an integrated look at the whole process including machine, spindle, cutting tool design and process conditions. Only this integrated view to all process related items enables running an innovative and effective process. The maximum stack size of 40 mm is another condition that requires a specific process to control the chip size to avoid an impact to the material. Here different concepts have been taken under consideration.
2015-09-15
Technical Paper
2015-01-2517
Sean Holt, Rider Clauss
Abstract Electroimpact has developed a novel method for accurately drilling and countersinking holes on highly convex parts using an articulated arm robotic drilling system. Highly curved parts, such as the leading edge of an aircraft wing, present numerous challenges when attempting to drill normal to the part surface and produce tight tolerance countersinks. Electroipmact's Accurate Robot technology allows extremely accurate positioning of the tool point and the spindle vector orientation. However, due to the high local curvature of the part, even a small positional deviation of the tool point can result in a significantly different normal vector than expected from an NC program. An off-normal hole will result in an out of tolerance countersink and a non-flush fastener.
2015-09-15
Technical Paper
2015-01-2500
Brigitte Vasques
The drilling of multi layers composite stacks remains a common process in aerospace industry. Research of productive solutions such as one shot and dry drilling operations to avoid reaming and lubrication are contemplated by aerospace customers on titanium multi layers composite applications. Those solutions permit to reduce the number of finishing operation and drilling time. Special ADEs (Advanced Drilling Equipment) machines are used to drill aircraft components in limited access areas. Parameters such as cutters, ADE machines type, rigidity clamping, cutting conditions, speed, feed, chip fragmentation and extraction are related and influence the holes quality. Titanium (TA6V) thickness and cutting configuration influence the cutter wear development. In this work, ADE and specific cutter geometries developed by Apex are used for the one shot dry drilling of titanium. Carbide cutters have been chosen for their resistance to the heat developed by titanium drill.
2015-09-15
Technical Paper
2015-01-2508
Jason Rediger, Kyle Fitzpatrick, Rob McDonald, Daniel Uebele
Abstract An improved aircraft assembly line incorporates fully automated robotic tool change. Ten machine tools, each with two onboard 6-axis robots, drill and fasten airplane structural components. The robots change 100% of the process tooling (drill bits, bolt anvils, hole probes, and nosepieces) to allow seamless transition across the entire range of hole and fastener sizes (3/16″-7/16″). To support required rate, total tool change time (including automatic calibration) is less than 80 seconds. This paper describes the robots and their end effector hardware, reliability testing, and simulations for both mechanical clearance and cycle time estimation.
2015-09-15
Technical Paper
2015-01-2490
Sylvain Guerin, Sylvain da Costa
The quality requirement for drilling operation in aerospace industry associated to the different material layers of the recent aircraft design is one of the most challenging issues for manufacturing engineers who want to design system for one-shot drilling operation. We have developed and validated in production a handheld electrical tool which is able to accurately monitor the drilling parameter and to adjust the drilling conditions to specific material in the stack-up. This “Smart Driller” achieves quality and performances equivalent to those obtained by the most advanced heavy automated drilling systems at a small portion of weight and cost.
2015-09-15
Technical Paper
2015-01-2489
Philippe Le Vacon, Thomas Buisson, Fabien Albert
This paper presents an innovative solution of portable drilling machine, lightweight and low cost, dedicated to drilling operations on single and double curved aircraft structure. Aircraft Standard drilling process mainly uses drilling templates combined with Automated Drilling Units (ADU) which is a very efficient solution. However, the management of templates and ADUs is a time consuming and costly task in regards to the large quantity of existing references spread over every aircraft production sites. Therefore, to help reducing those costs and also workload, the concept of the Numerical Template (NCT) has been designed, using classic and robust mechanical devices, hand-held, lightweight and universal. NCT architecture concept could led to a family of NCT with different dimensions of frame parts(X,Y,Z), fitted to the targeted area geometry. The system is able to guaranty an accuracy of ± 0.5 mm and a normality of ±0.5°.
2015-09-15
Technical Paper
2015-01-2509
Eric Reid
Abstract The Boeing Company has developed a mobile robotic drilling and fastening system for use in assembly processes on the lower panel of a horizontally fixtured wing. The robotic system, referred to as Lower-panel Drilling and Fastening System (LPDFS), was initially developed as part of an initiative to minimize facilities costs by not requiring costly foundation work. It is designed to operate with a high level of autonomy, minimizing operator intervention, including that required for machine setup and tool changes. System design enables positioning the work piece at a lower ergonomic height for concurrent manual processes. In all aspects of design, the system will maintain maximum flexibility for accommodating future manufacturing changes and increases in production rate, while meeting the strict accuracy requirements characteristic of aircraft manufacturing.
2015-09-15
Journal Article
2015-01-2501
Cosme de Castelbajac, Sylvain Laporte, Julian Lonfier, Emmanuel Puviland
Abstract Over the last few years, many aircraft production lines have seen their production rate increase. In some cases, to avoid bottlenecks in the assembly lines, the productivity of processes needs to be improved while keeping existing machine-tools. In this context, the case of drilling machine-tools tends to require particular attention, especially when multi-material parts are drilled. In such instances, the Vibration Assisted Drilling (VAD) process can be a way to improve productivity and reliability while keeping quality standards. This article presents a case of a drilling/countersinking process for stainless steel and titanium stack parts. Firstly, the article assesses the feasibility and benefits of using Vibration Assisted Drilling and Countersinking with the current cutting-tools.
2015-09-15
Journal Article
2015-01-2502
Jeremy Jallageas, Matthieu Ayfre, Mehdi Cherif, Jean-Yves K'nevez, Olivier Cahuc
Abstract This study investigates the self-adjusted cutting parameter technique to improve the drilling of multi-stacked material. The technique consists in changing the cutting strategy automatically, according to the material being machined. The success of this technique relies on an accurate signal analysis, whatever the process setting. Motor current or thrust force are mostly used as incoming signals. Today, analyses are based on the thresholding method. This consists in assigning lower and upper limits for each type of material. The material is then identified when the signal level is stabilized in between one of the thresholds. Good results are observed as long as signal steps are significantly distinct. This is the case when drilling TA6V-CFRP stacks. However, thrust force level remains roughly unchanged for AA7175-CFRP stacks, leading to overlapping thresholds. These boundary limits may also change with tool geometry, wear condition, cutting parameters, etc.
2015-01-01
Journal Article
2014-01-9105
Akram Faqeeh, Ahmed Sherif El-Gizawy
The present paper aims at optimization of multiple quality characteristics (dimensional accuracy and surface roughness) in dry drilling Ti-6Al-4V using TiAlN-coated carbide tool while the controllable factors are spindle speed and feed rate. To do so, desirability methodology is used to explore optimum conditions for concurrent optimization of the addressed quality characteristics. Central composite design (CCD) is used for experimentation. In order to create reliable models describing the process behavior, response surface methodology (RSM) is used.
2014-09-16
Journal Article
2014-01-2236
Julian Lonfier, Côme De Castelbajac
Abstract As aircraft programs currently ramp up, productivity of assembly processes needs to be improved while keeping quality, reliability and manufacturing cost requirements. Efficiency of the drilling process still remains an issue particularly in the case of CFRP/metal stacks: hot and long metallic chips are difficult to remove and often damage the surface of CFRP holes. Low frequency axial vibration drilling has been proposed to solve this issue. This innovative drilling process allows breaking up the metallic chips in such a way that jamming is avoided. This paper presents a case of CFRP/Ti6Al4V drilling on a CNC machine where productivity must be increased. A comparison is made between the current regular process and the MITIS drilling process. First the analysis and comparison method is presented. The current process is analyzed and its limits are highlighted. Then the vibration process is implemented and its performances are studied.
2014-09-16
Journal Article
2014-01-2241
Jamie Skovron, Laine Mears, Durul Ulutan, Duane Detwiler, Daniel Paolini, Boris Baeumler, Laurence Claus
Abstract A state of the art proprietary method for aluminum-to-aluminum joining in the automotive industry is Resistance Spot Welding. However, with spot welding (1) structural performance of the joint may be degraded through heat-affected zones created by the high temperature thermal joining process, (2) achieving the double-sided access necessary for the spot welding electrodes may limit design flexibility, and (3) variability with welds leads to production inconsistencies. Self-piercing rivets have been used before; however they require different rivet/die combinations depending on the material being joined, which adds to process complexity. In recent years the introductions of screw products that combine the technologies of friction drilling and thread forming have entered the market. These types of screw products do not have these access limitations as through-part connections are formed by one-sided access using a thermo-mechanical flow screwdriving process with minimal heat.
2014-09-16
Journal Article
2014-01-2258
Sylvain Laporte, Etienne Gueydon, Alain Auffret, Cosme De Castelbajac
Abstract In today's aircraft assembly process several new features make drilling operations very challenging according to production requirements. Parts are made of thin or thick multi-material stacks with a large scope to cover and complex assembly sequences. In addition, the current ramp-up in aircraft programs involves to improve productivity while keeping process quality and reliability. In this context robotic solution meets perfectly all these requirements as it is flexible, reconfigurable, fast and agile. Among the possible end-effectors, the Barrel Multi-Function End Effector (BMFEE) appears to be the most flexible solution to allow many different process configurations. The latest developments have been focused on the drilling equipment of this BMFEE. In fact the drilling process efficiency can be constantly improved especially in terms of reliability, quality and productivity. Therefore vibration-assisted drilling system has been integrated into the BMFEE drilling module.
2014-09-16
Journal Article
2014-01-2271
Ryan Haldimann, Daniel Orf
Abstract In an attempt to be more flexible and cost effective, Aerospace Manufacturers have increasingly chosen to adapt a manufacturing style which borrows heavily from the Automotive industry. To facilitate this change in methodologies a system for locating robots has been developed which utilizes cameras for both locating and guidance of a mobile platform for a robot with drilling and fastening end effector.
2014-09-16
Technical Paper
2014-01-2259
Greg Adams
Abstract Electroimpact has developed a second generation of mobile robots with several improvements over the first generation. The frame has been revised from a welded steel tube to a welded steel plate structure, making the dynamic response of the structure stiffer and reducing load deflections while maintaining the same weight. The deflections of the frame have been optimized to simplify position compensation. The caster mechanism is very compact, offers greater mounting flexibility, and improved maneuverability. The mechanism uses a pneumatic airbag for both lifting and suspension. The robot sled has been improved to offer greater rigidity for the same weight, and dual secondary feedback scales on the vertical axis further improve the rigidity of the overall system. Maintenance access has been improved by rerouting the cable and hose trays, and lowering the electrical cabinet.
2014-09-16
Technical Paper
2014-01-2246
Yanbin Yao
Abstract Drilling plays a significant process in the aircraft manufacturing. This paper develops a robot automatic drilling system for processing the titanium alloy, aluminum alloy and laminated composites component of aircraft. The accurate robot drilling system is comprised of ABB IRB6640-235 robot, drilling end-effector, end-effctor control system and vision system. Experimental results show that the system absolute location precision is within 0.3mm, and the drilling efficiency can be up to four holes per minute. The drilling efficiency and quality of the aircraft component can be increased immensely by the developed robot automatic drilling system.
2014-09-16
Journal Article
2014-01-2274
Riley HansonSmith, Alan Merkley
Abstract The Boeing Company is striving to improve quality and reduce defects and injuries through the implementation of lightweight “Right Sized” automated drill and fasten equipment. This has lead to the factory adopting Boeing developed and supplier built flex track drill and countersink machines for drilling fuselage circumferential joins, wing panel to spar and wing splice stringers. The natural evolution of this technology is the addition of fastener installation to enable One Up Assembly. The critical component of One Up Assembly is keeping the joint squeezed tightly together to prevent burrs and debris at the interface. Traditionally this is done by two-sided machines providing concentric clamp up around the hole while it is being drilled. It was proposed that for stiff structure, the joint could be held together by beginning adjacent to a tack fastener, and assemble the joint sequentially using the adjacent hole clamp up from the previous hole to keep the joint clamped up.
2014-09-16
Journal Article
2014-01-2234
Nelson W. Sorbo, Jason J. Dionne
Abstract The use of composite materials and composite stackups (CO-Ti or CO-Al) in aerospace and automotive applications has been and will continue to grow at a very high rate due to the high strength and low weight of the materials. One key problem manufacturers have using this material is the ability to efficiently drill holes through the layers to install fasteners and other components. This is especially true in stackups of CFRP and titanium due to the desire of drilling dry for the CFRP layer and the need for cooling when drilling the high strength Ti layer. By using CO2 through tool cooling, it is possible to protect both layers. Through work supported by the National Science Foundation (NSF) and Department of Energy (DOE) it is shown that CO2 through tool cooling productivity can be significantly increased while maintaining required hole tolerances in both the composite and Ti layers.
2014-09-16
Journal Article
2014-01-2255
Joseph R. Malcomb
Abstract Automated countersink measurement methods which require contact with the workpiece are susceptible to a loss of accuracy due to cutting debris and lube build-up. This paper demonstrates a non-contact method for countersink diameter measurement on CFRP which eliminates the need for periodic cleaning. Holes are scanned in process using a laser profilometer. Coordinates for points along the countersink edge are processed with a unique filtering algorithm providing a highly repeatable estimate for major and minor diameter.
Viewing 1 to 30 of 227

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