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This paper is about the use of the Six Sigma Methodology, to solve variation problems in the manufacture area, at one of the Delphi Automotive Systems unit that manufacturer electrical harness. The DMAIC framework was followed, the improvements were done, eliminating the rots causes, and the use of Six Sigma methodology, was showed very efficient in solve problems. The methodology power, is in using a structured frame work, the DMAIC (Define-Measure-Analyze-Improve-Control), completing by quality quality tools (Pareto Chart, Five Why's, Cause and Effect Diagram) and statistical analyses, for example: variance analyses, hypotheses tests and Design of Experiments.

Several heater cores failed due to erosion by cavitation. After analysis, most of failures were explained by the presence of impurities in the heater core. It was then decided with the customer to use CFD simulation in order to prove that the cavitation was not caused by design concept of the tank. In this paper, we present the results of heater core simulations done in 2D and in 3D with Fluent. The objective is to simulate the pressure and velocity distribution within the heater core and to verify if the zones of low pressure are below the saturation vapour pressure of the fluid causing cavitation. In these areas, the deterioration of the tubes might occur due to erosion by cavitation.

Bond wires are used in automotive electronic modules to carry current from external harness to components where flexibility under thermal cyclic loading is very essential between PCB (Printed Circuit Board) and connectors. They are very thin wires (few μm) made up of gold, aluminum or copper and have to undergo mechanical reliability to withstand extreme mechanical and thermal loads during different vehicle operation scenarios. Thermal reliability of bond wire is to make sure that it can withstand prescribed electric current under given boundary conditions without fusing thereby retaining electronic module's functionality. While carrying current, bond wire by virtue of its nature resists electric current flow and generates heat also called as joule heating. Joule heating is proportional to current flow and electrical resistance and if not handled properly can lead to thermal run away conditions.

This paper presents a simplified thermal model for round catalytic converters in steady state operation. Using this model, the analytic solution for the temperature distribution in the monolithic substrate is obtained. This analytic solution in the substrate is, then, combined with those in the intumescent mat [1] and the metal shell to obtain the temperature profile in the radial direction of the converter except for three unknown temperatures at the three material interfaces, which can be solved using an Excel application program. This analytical temperature solution facilitates the studies of the effects of various design parameters such as the exhaust gas temperature, exhaust gas flow rate, substrate cell geometry, converter dimensions, and ambient temperature and flow, etc.

Although the Six Sigma [1] concept has become very popular in industrial sectors, very little is said about how to start a successful implementation in a Corporation, or when it should be initiated, and the most important, who should be addressed to lead this task. Its methodologies are widely observed by different sectors of the automotive market, typically focusing in projects with a potential financial impact, following the DMAIC sequence. More than just financial return, this sophisticated tool, has a direct impact on Quality in different levels for both non-productive process and manufacturing process, that eventually would also affect some organizational structures that ultimately can be understood as reengineering.

The most popular aluminum alloys for semi-solid automotive components are A356 and A357. The density of rheocast semi-solid A357 is higher than die cast A357 and allows for both T5 and T6 heat treatment. The mechanical properties of rheocast semi-solid A357 was found to be more dependent upon the heat treat schedule and casting soundness than by the solid content of the semi-solid slurry or the globule shape.

Miniaturization is an important trend in many technology segments, once it can enable innovative applications generating new markets. This trend was begun in electronics industry after World War II and has spawned changes into automotive sector also. For Automotive Wiring Harness, miniaturization is clearly presented in most of the components, mainly because of its benefits like the potential of mass reduction, cost reduction and efficiency improvement. Furthermore the main voice of customer points to cable gauge reduction that represents a considerable challenge for connection manufacturing process due to quality control limitations presented by conventional crimp process for 0,35 [mm₂] cables and smaller. According to that, the scope of this article is to present, in details, a manufacturing process optimization for an alternative and more robust technology of joining copper stranded cables to tin brass terminals used on automotive wiring harness, Resistance Welding.

There are an increasing number of applications for resonant micromachines. Accelerometers, angular rate sensors, voltage controlled oscillators, pressure and chemical sensors have been demonstrated using this technology. Several of these devices are employed in vehicles. Vibrating devices have been made from silicon, quartz, GaAs, nickel and aluminum. Resonant microsystems are in constant motion and so present new challenges in the area of reliability for vehicular applications. The impact of temperature extremes, cyclic fatigue, stiction, thermal and mechanical shock on resonant device performance is covered.

Optimization of the mechanical aspects of a heated conical oxygen sensor for desired performances, such as low heater power, good poison resistance, fast light-off, and broad temperature range, etc. was achieved with computer modeling. CFD analysis was used to model the flow field in and around a sensor in an exhaust pipe to predict the convection coefficients, poisoning, and switching time. Heat transfer analysis coupled with electrical heating was applied to predict temperature and light-off time. Results of the optimization are illustrated, with good agreements between modeling and testing.

Long repetitive braking, such as one which occurs during a mountain descent, will result in a brake fluid temperature rise and may cause brake fluid vaporization. This may be a concern particularly for passenger cars equipped with aluminum calipers and with a limited air flow to the wheel brake systems. This paper describes the computer modeling techniques to predict the brake fluid temperature rise as well as other brake component temperatures during braking and heat soaking. Numerical results are compared to the measured vehicle data and the effects of relevant brake system parameters on the fluid temperature are investigated. The techniques developed in this study will help brake engineers to build a safer brake system and reduce the extensive vehicle tests currently required.

The four major discriminators for products in the market place are Technology, Quality,1 Cost and Delivery. Effective measurement systems and initial design quality have the largest impact on delivered field quality, program development cost and timing, as well as customer enthusiasm. System-level reliability testing methods have a major impact on the business health of any product. The implementation of laboratory forced failure testing in simultaneously applied energy environments has the largest influence for "designing in" field reliability and lowering development cost. Clearly a policy change from success based testing to forced failure testing has had the largest impact on results for the consumer.

The electric power required in automotive systems is quickly reaching a level that significantly impacts costs and fuel consumption. This drives the need to reconsider an electric energy management function. Fast evolving factors such as increasing power usage, and stricter engine management and reliability requirements necessitate a global vehicle approach to energy management. Innovations such as new powernet concepts (42 volt or dual voltage systems), new component technologies (high-performance energy storage, high efficiency and controllable generators), and global electronic and software architecture concepts will enable this new energy management concept. This paper describes key issues to maximize energy availability with reasonable components.

The utilization of Laser welding process has increased during last years in several areas of industry, due to many benefits that can be achieved with this technology, such as: flexibility, productivity and quality. Thus, the optimization of Laser welding processes has been considered as a “green field” to be explored by Laser manufacturers, automation companies and process/project engineers. Nowadays there are few researches that provide a roadmap for Laser welding processes improvement that approaches both the aspects and characteristics applied to evaluate the Laser weld application performance. Therefore, this paper has per its main purpose through an exploratory study to provide parameters toward continuous improvement of Laser welding process considering both types of Lasers: Laser spot weld and Laser seam weld of stainless steel joints, thus this work may be considered as theoretical and practical reference to be applied by people involved with Laser welding applications.

Desiring to push thermoplastic poly-olefin (TPO) technology to its fullest limits and to confirm our position as the leader in the manufacturing of environmentally friendly TPO instrument panels, we have designed a process to manufacture 100% recycled instrument panel skins. This closed-loop process begins with extruding 100% recycled TPO flake into sheet stock to be painted and vacuum formed. The painted sheet is vacuum formed and the offal is ground into regrind flake, ready to be extruded again, thus completing the closed-loop process. This paper will describe a 100% closed loop recycling process for TPO instrument panels, discuss the intense validation process for recycled material and prove the robustness and durability of this interior solution.

In this paper we discuss in detail an algorithm that addresses cylinder-to-cylinder imbalance issues. Maintaining even equivalence-ratio (ϕ) control across all the cylinders of an engine is confounded by imbalances which include fuel-injector flow variations, fresh-air intake maldistribution and uneven distribution of Exhaust Gas Re-circulation (EGR). Moreover, in markets that are growing increasingly cost conscious, with ever tightening emissions regulations, correcting for such mismatches must not only be done, but done at little or no additional cost. To address this challenge, we developed an Individual Cylinder Fuel Control (ICFC) algorithm that estimates each cylinder's individual ϕ and then compensates to correct for any imbalance using only existing production hardware. Prior work in this area exists1,2, yet all disclosed production-intent work was performed using wide-range oxygen sensors, representing cost increases.

Lead-free solders for electronics have been actively pursued since the early 1990's here and abroad for environmental, legislative, and competitive reasons. The National Center for Manufacturing Sciences (NCMS-US)1, the International Tin Research Institute (ITRI-UK)2, Swedish Institute of Production Engineering Research (IVF-Sweden)3, Japan Institute of Electronics Packaging (JIEP Japan)4, Improved Design Life and Environmentally Aware Manufacture of Electronics Assemblies by Lead-free Soldering (IDEALS-Europe)5, and, more recently, the National Electronics Manufacturing Initiative (NEMI-US)6 have been aggressively seeking lead-free solutions The automotive industry has some unique requirements that demand extensive testing of new materials and processes prior to implementation. The specific steps taken at Delphi Automotive Systems with lead-free solder will be described along with the lessons learned along the way.

Performance of two types of NOx adsorber catalysts, one based on Ba and the other based on Ba with alkali metals, was compared fresh and after thermal aging. Incorporation of sodium(Na), potassium(K) and cesium(Cs) into NOx adsorber washcoat containing barium significantly increases the NOx conversions in the temperature range of 350-600°C over that of the alkali metal free NOx adsorber catalysts. NOx performance benefit and HC performance penalty were observed on both engine dynamometer and vehicle tests for the “Ba+alkali metals” NOx adsorber catalysts. “Ba+alkali metals” NOx adsorber catalysts also demonstrate superior sulfur resistance with better NOx performance after repeated sulfur poisonings and desulfations over the “Ba based” NOx adsorber catalysts.

The fundamental relationship between semi-solid processing and microstructure and their effect on the flow characteristics of semi-solid metals have been studied for several years. However, how the process related microstructure influences fatigue properties has not been given the same attention. This study examines the influence of process-related microstructure on the fatigue properties of semi-solid formed A357 alloys. High-solid-fraction (62% solid) and low-solid-fraction (31% and 36% solid) semi-solid formed A357 was tested in axial fatigue with a stress ratio (R) equal to -1. The high solid fraction (HSF) material had better fatigue properties than the low solid fraction (LSF) material. This is attributed to the fatigue crack initiation mechanisms, as related to the fatigue crack initiation features and the strengths of the materials.

This paper summarizes the results of an investigation of high risk, high potential technologies for hybrid vehicle drive applications and investigate potential solutions for the technical risk items associated with these technologies. The study consisted of the design, build, and test of different types of electric machines to understand their performance, efficiency, and manufacturability to develop hybrid vehicles with cost and performance similar to the present day IC engine based vehicles, but with lower emissions and better fuel economy. Machine technologies examined include synchronous reluctance, permanent magnet, and switched reluctance. Test data for various machine technologies is presented along with a discussion of the technical risk associated with each technology.

Thermoplastic polyolefin (TPO) instrument panel skins are in demand in Europe and Asia as a solution to final product disposition environmental concerns. In North America TPO is valued for its durability characteristics (particularly heat and UV aging) and capability for deployment of seamless airbags at cold temperatures. Desiring to have an environmentally “green” system to create the “green” product, Delphi designed a manufacturing process with in-plant closed loop recycling of 100% offal directly back into the skin and the use of waterbased coating system for combating concerns with solvents. Delphi's development of recyclable TPO skin for instrument panels was introduced on 1997 production of Mercedes-Benz M-class. The paper will describe how the systems approach was used in overcoming the challenges involved in closed loop recycling of engineered offal during sheet manufacturing and thermoforming processes and the implementation of waterbased primer and topcoat systems.