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Automotive manufacturing constantly demands an enhancement of lean manufacturing ability. A proposed Flexible Control Structure (FCS) shows its capability to accommodate that anxiety. The FCS is a multi-control mechanism. With the FCS, the control scheme can be reconfigured logically, corresponding to different system input capacities. A Robot, Computer and Vision (RCV) Inspection System was simulated as an integrated manufacturing testing environment. FCS and other control structures were implemented individually within the testing environment. As the result of data analysis, Flexible Control Structure was found to be most efficient in the case of mixed capacity scenario.

In the past, the performance of motorcycle engines has improved quite rapidly through intensive competition in racing and in the marketplace. Motorcycle engines have contributed to the technological progress of internal combustion engines (hereafter abbreviated as ICE). Today's environmental concerns require motorcycle engines to improve fuel economy and exhaust emission pollutants. After examination of potential measures to improve the thermal efficiency of small engines, it was concluded that if engineers of motorcycle engines fail to take on new ideas such as those being developed in cold fusion, it is foreseen that motorcycle engines will be replaced with new power plants as was seen on locomotives in the past.

The application of reliability criteria in the maintenance management is assuming high relevance in the industrial field in consideration of the savings obtained by them in the management costs conjugated with an availability and reliability improvement. In this frame, ENEA (an Italian Research Institute) developed, in collaboration with some European companies (ATC, ANSALDO, SIVECO France and IIS sa) and within a Project financed by the European Commission (Contract No BRPR - CT96-0211), a software tool to be applied for the improvement of the maintenance planning of each type of industrial system on the basis of reliability and costs criteria.

The problem of supplying JIT assembly workstations from a central depot with a goal of minimizing inventory and vehicle requirements is the focus of this paper. To minimize work-in-process inventory, the quantity of component parts delivered to each workstation must be just enough to satisfy production until the next delivery of components. To minimize vehicle requirements, there should be no vehicle idle time. The problem is modeled as a vehicle routing problem with a nonlinear capacity constraint. A heuristic solution procedure is outlined and a relaxed formulation is given to provide a lower bound on the number of vehicles required.

Middle management participation is crucial to the success of lean manufacturing. Typically in changing a manufacturing operation, efforts are focused on high-level management in regards to why the change is necessary and what benefits can be expected. Likewise, efforts are made to achieve buy-in from the line workers in accepting the program and ease any apprehensions of job security. The middle manager is regularly left with only a partial understanding of why lean manufacturing is necessary. The middle manager has the responsibility of supporting the management’s decision while accepting the risk of failure and possible reprisal, and yet, is not regarded as a key player. The middle manager must be knowledgeable of the job the workers do and be able to alleviate any problems encountered by implementing the lean tools. Without a focused approach aimed at the middle managers, they cannot be expected to genuinely support program.

New manufacturing systems are creating a competitive world. The challenge for new facilities consists in creating lean thinking and focusing on time and waste reduction through the use of continuous improvement principles. In new facilities it is easier to create this environment.

This paper reports the results of a research study to identify and analyze the types of problems faced by just-in-time (JIT) automotive suppliers in Alabama. A 1998 survey of Alabama JIT automotive suppliers focused on twenty major JIT-related problems and one hundred company characteristics related to customers, employees, extent of JIT implementation, work environment, carriers, and other issues. The analysis of the survey results included statistics to evaluate how closely Alabamabased JIT companies resembled JIT companies located elsewhere. In addition, hypotheses were tested to identify possible relationships between company characteristics and specific JIT-related problems. The analysis provided insight into the demographics, common problems, and most troublesome issues related to JIT implementation in the state’s automotive industry.

Two-dimensional (2D) codes offer several advantages over conventional bar codes for marking parts and assemblies. This paper will review the key attributes of 2D codes, including data density, readability, and error correction capability. Featured applications will demonstrate the use of 2D codes to identify and track automotive parts throughout production and assembly processes. Although 2D codes can be applied by contact and non-contact technologies, this paper will focus on ink jet printing and laser coding to provide specific examples of the benefits of on-line, real time, non-contact product identification. Finally, code reading devices, on-line and hand-held, will be introduced.

Headlamp aim is a complex vehicle feature which is important for customer safety, and faults in the assembly adjustment process represent an important aspect of automotive faults. This paper examines the issue of headlamp aim through defining the fundamentals of headlamp aim, the different methods of aim setting, analysing two different aim measurement systems, and outlining the factors which cause variation in this vehicle characteristic. The results of conducted testing isolated the significant variables which influenced vertical headlamp aim. These factors were then utilised in the development of appropriate plant and customer specifications. For the vehicle types examined in this research, fuel tank quantity was found to be the most significant variable in terms of influencing headlamp aim from the plant to the customer.

Conductive heat resistance seam welding (CHRSEW) is a new process developed at Edison Welding Institute for creating butt joints on aluminum sheet. The process uses conventional resistance seam welding equipment, and takes advantage of steel cover sheets on either side of the intended joint. Resulting joints are fusion in character, and can be manufactured at very high welding speeds (∼ 3 to 4 m/min). In this study, the conductive heat resistance seam welding process was extended to some new applications. These included joining a 7075-T6 alloy, and a dissimilar thickness 1- to 2-mm 5754 configuration. The former is generally considered unweldable by fusion methods, and is of considerable interest for aerospace applications. The latter is representative of a tailor welded blank for automotive applications. Resulting welds were evaluated using metallurgical examinations and mechanical testing.

With the increased focus on weight reduction in automotive body-in-white panels, laser welded blanks (LWB) have been embraced in the design of major body panels and closures. Current applications for laser welded blanks generally consist of two differently gaged blanks combined via a linear weld line. Advancing technology now offers opportunities to incorporate nonlinear weld lines and part configurations of more than two blanks. This study shows how a liftgate inner panel featuring non-linear laser weld lines can be designed, which will decrease weight and cost, and improve stiffness performance.

The control system in our welding cell is based on multiple sensing technology and fuzzy logic algorithm. The first generation of controller is a vision based fuzzy logic controller (FLC). Video signals from weld plume in real time are analyzed to generate information for the fuzzy logic controller to adjust welding speed in order to maintain consistent welds. The second-generation controller incorporates weld fault monitoring technology into the existing FLC to form a self-adapting neural-fuzzy control system. Technology of multiple-color optical emission sensing and neural network analysis is the key feature of this controller. The third-generation controller will add multi-spot detection technology, which detects the gap opening or small offset from the desired beam position on the joint and thus allows for adaptive adjustment of laser beam focal spot size.

Aluminum tailor welded blanks in the automotive industry continues to grow due to the light weight of aluminum itself and the characteristics of the tailor welded blanks. It has been found that welding of aluminum blanks with co2 laser is difficult but doable in a production environment and using high power CW Nd:YAG laser can obtain sound results with a much wider process parameter window. However, currently, high power CO2 lasers (in the range of 8 kW) are still the dominate laser sources in steel tailor welded blank companies in north America. Will these lasers be able to weld aluminum tailored blanks if the demand of aluminum tailor welded blanks increases? This study employed twin spot and beam shaping methods to weld 1mm combined with 2 mm tailored blanks using high power (9 kW maximum) CO2 laser for both 5754-O and 6111-T4 alloys. The results show that high power CO2 lasers can be used for welding 5754-O and 6111-T4 aluminum alloys with very precise parameter settings.

The use of numerical simulation in the design of stamped components has become common industrial practice. Inverse one-step codes are among the fastest to provide answers but, unlike incremental codes, they need an additional verification phase. Given this context, IVECO has conducted experimental testing work on the plastic deformations measured on two industrial components obtained by means of sheet steel stamping. The two components, one with structural functions (sliding door upper reinforcement) and the other one with esthetic functions (rear left door skin), have been selected as representative of the various feasibility and process issues connected with sheet metal drawing.

In this article, the enforcement of a user defined blank shape and size is formulated into an inverse finite element program, FAST_FORM3D. In this type of analysis, the geometric input to the program is a designed part mesh with extended edge and the boundaries of a user defined blank. An iterative procedure is developed to construct a new part mesh, which, upon unfolding, produces a blank that matches closely the user defined blank. The new technique is tested using the NUMISHEET'93 deep drawn square box benchmark. A convergence study is presented to show the performance of the developed iterative scheme. A practical example is included to demonstrate the usability of the new technique in design cases when simple straight-sided blank is needed for ease of blanking operation. The predicted thickness strain displays a good agreement with the experimentally measured results.

A deep-drawing grade AKDQ steel sheet was tested to determine the Forming Limit Diagrams (FLDs) using two different forming methods to identify points where the incipient necking started. With the conventional out-of-plane spherical forming test, incipient necking points were determined from the formed dome samples at areas diametrically opposite to the necked and fractured locations. With the Marciniak in-plane forming test, incipient necking points were determined from real-time video images obtained during the experiment. These images were analyzed with strain-measurement software to determine the strain distributions in the samples. Various data plotting schemes were explored to produce meaningful results for the flat-bottom in-plane tests. These methods included “best fit” line analysis and strain vs. time plots. The final outcome is reasonably consistent with published FLD data.

This paper presents the application of the different approaches available for the analysis of the sheet metal forming process on an industrial part (RENAULT KANGOO front fender). It is nowadays accepted in the engineering community that inverse, simplified direct and incremental direct approach are complementary and should be used in the development of a stamped part. The paper shows the formability analysis of the TWINGO door and hatchback at different stages of the part and process design, identifies the optimal approach at different stages and gives indication as to the relative speed, accuracy and quality of the different simulation solutions.

In this paper the effects of pulsating blankholder forces in deep draw processes for sheet metal parts are discussed. Areas with and without tangential compressive stresses in the flanges, which are located between the binders, are discussed separately. Areas without tangential compressive stresses can be simulated by a special friction strip-draw test using a pulsating normal force ( representing the blankholder force ). Investigations using this equipment show that by pulsating blankholder forces it is possible to avoid galling and to reduce the friction force. Areas with tangential compressive stresses can be simulated by deep drawing axissymmetric cups using a pulsating blankholder force. Investigations with this equipment show that without increasing the danger of wrinkling the friction forces can be reduced by pulsating blankholder forces, when a certain frequency limit is reached.

Pressures to increase the recyclable and recycled content of passenger vehicles are accelerating. In Europe, there is interest in eliminating halogenated polymers. Globally, more and more concern is focused on materials and methods that are ecologically friendly. Automakers and their suppliers are being encouraged to design and assemble components in new ways to facilitate separation, identification, and resource recovery at the end of the vehicle’s useful life - something that is not only good for the environment, but also the bottom line. One area of the vehicle that has proved challenging for applying such design for disassembly and recycling (DFD/R) principles has been the interior, owing to the sheer number of materials used there, and the great number of laminate structures that make disassembly nearly impossible. A good example is a door panel inner, which typically consists of a rigid plastic substrate, a foam pad, and a vinyl, leather, or cloth covering.

In cooperation with industrial companies at the Institute for Metal Forming Technology (IFU) of the University of Stuttgart, Germany, a new press concept specially for hydroforming tubes and extrusions was developed. The press has a capacity of 3500 tons closing force and a press table size of 2500 mm × 900 mm. A great reduction in costs can be achieved by integrating spacers between the frame of the press and the ram. This paper introduces this new press.