Search Results

This paper describes the new inline 4-cylinder QR engine series that is available in 2.0-liter and 2.5-liter versions. The next-generation QR engine series incorporates new and improved technologies to provide an optimum balance of power, quietness and fuel economy. Its quiet operation results from the adoption of a compact balancer system and the reduced weight of major moving parts. Power and fuel economy have been enhanced by a two-stage cooling system, a continuous variable valve timing control system, a dual close coupled catalyst system, electronic throttle control and an improved direct-injection system. The latter includes an improved combustion chamber concept and improved fuel spray characteristics achieved by driving the injector by battery voltage. A lightweight and compact engine design has been achieved by adopting a high-pressure die cast aluminum cylinder block, resin intake manifold and rocker cover and a serpentine belt drive.

Due to environmental and legislative concerns, less polluting and more efficient vehicle powertrain systems must be developed. A first step is a simple, low cost system such as the presented Engine Stop-Start (ESS) system. A 1.9 liter four-cylinder spark-ignition engine with a four-speed automatic transmission was modified to enable fuel off-on transitions during decelerations and stops. Additional hardware includes a 7 kW electric motor-generator, a power electronics module with an inverter and a DCDC converter, a 36 Volt nominal battery system, and minor modifications to the transmission. A control scheme was developed which takes advantage of the system's fuel saving potential while minimally affecting driveability. Tests have shown EPA City fuel economy gains of approximately 12-14 percent while maintaining the same emissions classification. The EPA Highway fuel economy was increased by approximately 1 percent.

The design of the newly developed Toyota AZ series 4 cylinder engine has been optimized through both simulations and experiments to improve heat transfer, cooling water flow, vibration noise and other characteristics. The AZ engine was developed to achieve good power performance and significantly reduced vibration noise. The new engine meets the LEV regulations due to the improved combustion and optimized exhaust gas flow. A major reduction in friction has resulted in a significant improvement in fuel economy compared with conventional models. It also pioneered a newly developed resin gear drive balance shaft.

A technique to strengthen body frame with a polymeric structural foam has been developed with benefits of reducing vehicle weight and improving drivability and fuel economy. The idea of this new technology was evolved from the concept that body frame strength will increase drastically if the body frames are prevented from folding on collision. The energy of a collision impact would be effectively absorbed if weak portions of body frames are reinforced by a high strength structural foam. The new technology composed of the high strength structural foam and a light-weight frame structure with partial foam filling is reported here.

Automotive engineers are challenged with increasing fuel economy in transportation vehicles by reducing weight. Aluminum castings are replacing cast iron components as one way to reduce weight in cars. Many of the aluminum castings produced for automobiles today are made with a sand core to form the internal cavity of the automotive component. Currently, the most popular choice of sand binder system in core making is the phenolic urethane cold-box binder system. This system, however, was not designed for use at aluminum pouring temperatures. The collapsibility of a phenolic urethane cold-box core is not sufficient for expedient shakeout in an aluminum casting. Because of this, many aluminum castings must undergo secondary core removal processes. This reduced shakeout effectiveness limits the designer in the casting geometries available and adds cost to the part.

This paper introduces the new 1.6L engine family, designed and developed by the Chrysler group of DaimlerChrysler Corporation in cooperation with BMW. An overview of the engine's design features is provided, with a detailed review of the performance development process with emphasis on airflow, combustion, thermal management and friction. This information is presented, to provide an understanding of how the engine simultaneously achieves outstanding levels of torque, power, fuel consumption, emissions and idle stability. The use of analytical tools such as Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) in the optimization of the engine is shown.

After an absence of nearly two decades from General Motors vehicles, a state-of-the-art all new inline six cylinder engine will be introduced for the 2002 model year as the standard engine in a new line of midsize Sport Utility Vehicles (SUV's). The new VORTEC 4200 I6 Engine (Figure 1) brings the technical sophistication of premium passenger car engines to the truck market delivering power exceeding most competitor's V8's, with exceptional low and midrange torque, yet providing best in class fuel efficiency. It is designed to provide a high level of reliability, emit low emission levels, exhibit quiet, smooth, and refined engine operation, and is lightweight. The inline configuration provides an elegant solution to meeting customer demands with premium technology. Features include dual overhead cams - four valves per cylinder, variable exhaust valve timing, all aluminum construction for the cylinder block and cylinder head, and electronic throttle control.

The rapid pace of change in the transportation industry is leading design and product engineers to reconsider traditional notions in the design of both new and existing components and systems. The need to remove weight from vehicles to improve gas mileage and meet stringent pollution control regulations while achieving higher performance are some of the major challenges confronting the engineer today.

The last ten years has seen the North American automotive industry increasing its use of magnesium castings at an annual rate of around 15% and this rate of growth is expected to continue for at least the next ten years. The main driving force for this increasing use of magnesium is the need to reduce vehicle weight and improve fuel economy. Magnesium alloys are amongst the lightest structural materials available, however, they do cost more per unit mass than competing materials such as steel and aluminum and the automotive industry is reluctant to pay a premium for weight saving. However, in spite of an apparent cost penalty, magnesium castings are currently used in a number of automotive body, chassis and powertrain applications and this paper will review these applications. There is also a significant potential for future growth in the use of magnesium casting by the automotive industry where there may be little or no cost penalty.

Recently, EPS (Electrical Power Steering) is being widely applied in order to reduce fuel consumption and decrease installation problems of the power steering system. EPS also decreases development time and cost of the steering system due to its ease of tuning. As we mentioned in the former paper “2000-01-0824”, the larger output motors are required. Upon developing the higher output motors, Mitsubishi realized that the EPS Systems brought about high acoustic noise, vibration, large torque ripple and friction loss. We have developed a very silent motor based on our unique technology. This involved a very unique electromagnetic force and mechanical vibration analysis method. Our super silent motor is so quiet, that the occupants of a vehicle can not distinguish the motor noise even when the motor is installed in the vehicle cabin.

A catalytic deSoot-deNOx system, comprising Pt and Ce fuel additives, a Pt impregnated wall-flow monolith soot filter and a vanadia-type monolithic NH3 - SCR catalyst, was tested with a 2 cylinder DI diesel engine. The soot removal efficiency of the filter was 98-99% (mass), the balance temperature (stationary pressure drop) was 315 °C at an engine load of 55%. The NOx-emission at high loads is around 15% lower than those of engine running without fuel additives. The NOx conversion ranged from 40 to 73%, at a NH3/NOx ratio of 0.9, both measured at a GHSV of 52,000 l/l/h. The maximum NOx conversion was obtained at 400 °C. No deactivation was observed after 380 h time on stream.

Particulate emission control from diesel engines is one of the major concerns in the urban areas in California. Recently, regulations have been proposed for stringent PM emission requirements from both existing and new diesel engines. As a result, particulate emission control from urban diesel engines using advanced particulate filter technology is being evaluated at several locations in California. Although ceramic based particle filters are well known for high PM reductions, the lack of effective and durable regeneration system has limited their applications. The continuously regenerated diesel particulate filter (CRDPF) technology discussed in this presentation, solves this problem by catalytically oxidizing NO present in the diesel exhaust to NO2 which is utilized to continuously combust the engine soot under the typical diesel engine operating condition.

The aggressive reduction of future diesel engine NOx emission limits forces the heavy- and light-duty diesel engine manufacturers to develop means to comply with stringent legislation. As a result, different exhaust emission control technologies applicable to NOx have been the subject of many investigations. One of these systems is the NOx adsorber catalyst, which has shown high NOx conversion rates during previous investigations with acceptable fuel consumption penalties. In addition, the NOx adsorber catalyst does not require a secondary on-board reductant. However, the NOx adsorber catalyst also represents the most sulfur sensitive emissions control device currently under investigation for advanced NOx control. To remove the sulfur introduced into the system through the diesel fuel and stored on the catalyst sites during operation, specific regeneration strategies and boundary conditions were investigated and developed.

Beside the traditional prediction of stresses and verification by mechanical testing the optimization of cylinder liner bore distortion is one of today's most important topics in crankcase structure development. Low bore distortion opens up potentials for optimizing the piston group. As the piston rings achieve better sealing characteristics in a low deformation cylinder liner, oil consumption and blow-by are reduced. For unchanged oil consumption and blow-by demands, engine friction and subsequently, fuel consumption could be reduced by decreasing the pre-tension of the piston rings. From the acoustical point of view an optimization of piston-slap noise is often based on an optimized bore distortion behavior. Apart from basics to the behavior of liner bore distortion the paper presents advanced analytical and empirical methods for detailed prediction, verification and optimization of bore distortion taking into account the effective engine operation conditions.

One of the most attractive features of hybrid vehicles powered by SI-engines with three way catalysts is the potential of reaching extremely low emissions. In conventional drive trains, limitations in the air/fuel control result in lambda excursions during transients. These deviations from the ideal lambda result in increased emissions. In a hybrid vehicle, rapid load and speed changes of the SI-engine could be limited to an acceptable level as the battery acts as a power buffer. However, the efficiency of charging and discharging the battery is rather low, which means that excessive power buffering will increase the fuel consumption of the vehicle. Thus it is of great importance to know what degree of speed and load changes the air/fuel control system could cope with without an increase in emissions.

With the introduction of unleaded gasoline, special fuel agents have appeared on the market for lubricating and cleaning the valve seats. These fuel agents often contain alkali metals that have a significant impact on the ion current signal, thus affecting strategies that use the ion current for engine control and diagnosis, e.g. for estimating the location of the pressure peak. This paper introduces a method for making neural network algorithms robust to expected disturbances in the input signal and demonstrates how well this method applies to the case of disturbances to the ion current signal due to fuel additives containing Sodium. The performance of the neural estimators is compared to a Gaussian fit algorithm, which they outperform. It is also shown that using a fuel additive significantly improves the estimation of the location of the pressure peak.

When developing Diesel engines, some key points will always exist: minimizing noise, reducing internal friction - ultimately fuel consumption - and preventing liner cavitation. To reach economically these targets, the assistance of sophisticated simulation tools is necessary. By means of some selected examples, the simulation procedures and the quality of their results are demonstrated.

This paper describes the recent efforts on developing an automotive climate control system throughout integrating an electrically-controlled variable capacity scroll compressor with a fuzzy logic control-based refrigerant flow management. Applying electrically-controlled variable capacity compressor technology to climate control systems has a significant impact on improving vehicle fuel economy, achieving higher passenger comfort level, and extending air and refrigerant temperature controllability as well. In this regard, it is very important for automotive climate control engineers to layout a system-level temperature control strategy so that the operation of variable capacity compressor can be optimized through integrating the component control schemes into the system-level temperature control. Electronically controlled expansion devices have become widely available in automotive air conditioning (A/C) systems for the future vehicle applications(1, 2, 3 and 4).

An electromechanically driven valve train offers unprecedented flexibility to optimize engine operation for each speed load point individually. One of the main benefits is the increased fuel economy resulting from unthrottled operation. The absence of a restriction at the entrance of the intake manifold leads to wave propagation in the intake system and makes a direct measurement of air flow with a hot wire air meter unreliable. To deliver the right amount of fuel for a desired air-fuel ratio, we therefore need an open loop estimate of the air flow based on measureable or commanded signals or quantities. This paper investigates various expressions for air charge in camless engines based on quasi-static assumptions for heat transfer and pressure.

This paper introduces the preliminary simulation of a four-stroke spark ignition engine. An arbitrary heat release formula was used to predict the cylinder pressure, which was used to find out the indicated work done. The heat transfer from the cylinder, friction and pumping losses also were taken into account to predict the brake mean effective pressure, brake thermal efficiency and brake specific fuel consumption. Most of the parameters that can affect the performance of the four stroke spark ignition engines such as equivalence ratios, spark timing, heat release rate, compression ratios, compression index and expansion index are studied. The use of a real combustion curve has a profound influence on the similarity of the pressure-volume profile to that seen for the real engine. The modeling process is obviously getting closer to reality and is now worth pursuing as a design aid.