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Technical Paper

Flexible Fuel and manufacturing dispersion

Back to the non Flex Fuel vehicles, the knock control system was designed and calibrated to absorb differences between engines (mainly compression ratio) and to protect the engine against knock damage (a correction up to 4 degrees BTDC was usually enough). But now, two new variables get in the scene: Flexible Fuel strategy, working from E22 to E100 (all blends in between) and small displacement (1.0 liter) high compression ratio engines. In this new scenario the system must be capable of correcting all spark advance differences, once knock control system acts as a safety feature, protecting the engine even if the fuel learning shows some deviation. In addition to that, we have the compression ratio variation between minimum and maximum limits. Since the engine is small (as well its combustion chamber), each tenth of a millimeter difference during manufacturing process, results in an important final compression ratio variation.
Technical Paper

Flexible Fuel meets high compression engines: The knock control challenge

Since the appearance of the first flexible fuel vehicle back in 2003, many improvements have been done in order to deliver a more reliable and more efficient engine package. The increase in compression ratio is one of the mechanisms used in performance pursuit and to guarantee the engine durability meeting fuel economy requirements, running with fuels from regular E22 to E100 under high compression, many challenges were faced. The pre-ignition running at low engine speeds and mid to high loads had to be controlled, maintaining a reasonable driveability. Increasing the engine speed across its useful band, a special knock event could occur. It is special because results in peak pressures up to 15.000 kPa, named “single strong knock” and is present mainly at highest closed-loop load operation. In addition of that, design limitation was the cause for cylinder #04 low sensitivity. This characteristic narrowed the spark correction band resulting in destructive knock activity.
Technical Paper

Throttle Position Sensor Components Assembly Integrated into the Throttle Body Manufacturing Process

In the engine management systems field, there is lack of sensors locally built and available for sale in Brazil. Therefore, many auto parts companies have to import them affecting directly the final products costs (technology know-how/development costs, import taxes and other material handling/custom related costs). This paper was motivated to study an alternative for a simple, cheaper and locally made throttle position sensor. The choose of this part was because the fact that it is one of the most expensive in the throttle body bill of. For developing this new alternative, it was used a tool called value analysis and value engineering. The outcome of this study was a throttle position sensor function integrated to the throttle body manufacturing line with the advantages that 100% components can be locally purchased, improved robustness against humidity and component quantity reduction by 40%. Therefore achieving more value added.
Technical Paper

Gear Whine Reduction for a New Automatic Transmission

Gear whine in 1st and 2nd gears in a new rear wheel drive automatic transmission was identified as a potential customer dis-satisfier. Improvements to the vehicle system were implemented, but did not sufficiently reduce the noise. CAE modeling and hardware testing were used for gear tooth optimization, transmission system, driveline, and vehicle system studies. The planetary gears were re-designed with increased contact ratio, and significant interior noise reduction was achieved; but some vehicles still had excessive noise due to gear parameter variability from multiple sources. Using a DOE and statistical studies, a set of gear parameter targets were identified within the tolerances of the design, which achieved the program objectives for noise.
Technical Paper

Analysis of Factors Affecting Rainwater Ingestion into Vehicles HVAC Systems

The penetration of rainwater through the heating ventilation and air conditioning system (HVAC) of a vehicle directly affects the provision of thermal comfort within the vehicle passenger compartment. Present vehicle designs restrict considerably the air-management processes due to reduced space and tighter packaging. The motivation for the study is to get an insight into factors affecting the water ingress phenomenon when a stationary vehicle is subjected to water loading such as heavy rain when parked or waiting in a traffic light or when in a car wash. The test programme made use of a compact closed circuit full-scale automotive climatic wind tunnel that is able to simulate wind, rain and road inclination. The tunnel was developed as part of the collaborative research between the Flow Diagnostics Laboratory (FDL) of the University of Nottingham and Visteon Climate Control Systems [1].
Technical Paper

Lightweight Thermoplastic Composite Throttle Bodies for Car and Truck Applications

The drive to reduce weight, simplify assembly, and cut total system cost in today's vehicles is relentless. Replacing metal systems with thermoplastics has been of considerable interest in the engineering community. The current generations of engineering thermoplastic resins are enabling the use of plastic systems in demanding underhood applications. Technical data and discussion regarding the materials, design, molding, and assembly of lightweight composite throttle bodies will be presented in this paper. Comparisons with machined aluminum throttle housings are drawn to establish a baseline with the throttle body housing component that is most common in production today. Design flexibility and process simplification are some of the approaches highlighted. Much of the technical information provided in the paper applies to both cable driven mechanical throttle bodies as well as electronic throttle bodies under development.
Technical Paper

Future Automotive Multimedia Subsystem Interconnect Technologies

For the past decade or so, automotive entertainment subsystem architectures have consisted of a simple Human Machine Interface (HMI), AM-FM tuner, a tape deck, an amplifier and a set of speakers. Over time, as customer demand for more entertainment features increased, automotive entertainment integrators made room for new features by allowing for the vertical integration of analog audio and adding a digital control. The new digital control came to entertainment subsystems via a low-speed multiplexing scheme embedded into the entertainment subsystem components, allowing remote control of these new features. New features were typically incorporated into the entertainment subsystem by independently packaging functional modules. Examples of these modules are cellular telephone, Compact Disc Jockey (CDJ), rear-seat entertainment, Satellite Digital Audio Radio System (S-DARS) receiver, voice and navigation with its associated display and hardware.
Technical Paper

Numerical Study on Swirl-Type High-Dilution Stratified EGR Combustion System

High-dilution stratified EGR combustion system operating at stoichiometric air-fuel ratio (A/F) could offer significant fuel economy saving comparable to the lean burn or stratified charge direct injection SI engines, while still complies with stringent emission standards by using the conventional three-way catalytic converter. The most critical challenge is to keep substantial separation between EGR gas and air-fuel mixture, or to minimize the mixing between these two zones to an acceptable level for stable and complete combustion. Swirl-type stratified EGR and air-fuel flow structure is considered desirable for this purpose, because the circular engine cylinder tends to preserve the swirl motion and the axial piston movement has minimal effect on the flow structure swirling about the same axis. In this study, KIVA3V was used to simulate mixing and combustion processes in a typical pent-roof gasoline engine cylinder during compression and expansion strokes.
Technical Paper

Improved Automatic Transmission Warmup - Stand Alone Oil to Air (OTA) Transmission Cooling Strategy with Thermostatic Cold Flow Bypass Valve

The stand alone oil to air (OTA) transmission cooling strategy provides improved transmission cooling under high ambient air temperature operating conditions, which improves transmission reliability, durability and overall customer satisfaction. Another means of improving reliability and durability is through improved transmission warmup under low ambient air temperature operating conditions. To allow for improved transmission warmup, a thermostatic cold flow bypass valve has been incorporated into the transmission oil cooler. The bypass valve shuts off flow to the transmission oil cooler until a predetermined fluid temperature has been achieved. Once this temperature is reached, oil is allowed to flow to the transmission oil cooler. Visteon Climate Control Systems (VCCS) has tested both the stand alone OTA transmission cooling strategy with thermostatic cold flow bypass valve and the conventional transmission cooling strategy, comparing the transmission system warmup rates.
Technical Paper

A New Design of Optical In-Cylinder Pressure Sensor for Automotive Applications

This paper describes a new design of in-cylinder pressure sensor for automotive applications using optical technology. The technology has been applied to a direct injection diesel engine and compared against reference sensors. The rapid expansion in use of fiberoptics in other industries, primarily telecommunications, has supported the development and cost reduction of the technology to the point where it can be considered for automotive applications. Automotive environments are much harsher than standard telecommunications, so the challenge is to develop and package the technology to operate reliably in an engine bay environment. The sensor system consists of a passive sensor head employing a silicon diaphragm responding to the applied pressure and an integrated optical signal processing chip which contains an optical interferometer, light source, and photodiode.
Technical Paper

Closed-Loop Recycling of Monomaterial Door-Panel Systems

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.
Technical Paper

Design and Implementation of a Dual Mode Speed Loop Controller for a Dynamometer-based Vehicle Simulation System

The work described in this paper was carried out on a specialist engine dynamometer which allows accurate simulation of in-vehicle conditions. This is achieved by the use of a clutch between the engine and dynamometer which allows realistic simulation of gearchanges. The presence of a clutch means that the dynamometer has two distinct modes of operation, corresponding to a engaged or disengaged clutch. This paper describes the design of a speed control scheme, providing bumpless transfer between two controllers, which has been developed to satisfy the differing control requirements of disengaged and engaged operation. Brief discussion of the controllers and bumpless transfer scheme is followed by presentation of test results. Finally, the performance of this scheme is compared with that of an existing hardware controller.
Technical Paper

Development of Dust Separator/Filter for Automotive Fuel Vapor Storage Systems (FVSS)

Fuel Vapor Storage Systems (FVSS) on automobiles are susceptible to particle contamination. This is especially true for FVSS components mounted under the automobiles (undercarriage, chassis frame, etc.) and required to meet stringent EPA standards. Particle contamination significantly increases system restriction and reduces the effectiveness of FVSS. This paper describes a dust separator/filter developed to protect the FVSS. Accelerated field durability evaluations and measurement techniques were developed to identify clean locations, ingested contamination levels and ingested contaminant size distributions. Based on field evaluations, test methods were developed in the lab to evaluate effectiveness of several devices to control and reduce contamination. The dust separator design developed was a combination of baffle separators in series with an open cell foam filter. The dust separator was designed to meet and exceed several vehicle system design requirements.