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Toyota's Comprehensive Environmental Technology: Providing Choices for Sustainable Mobility

2011-11-04
In the pursuit of a sustainable transportation systems, Toyota is considering a comprehensive approach pursuing multiple advanced technologies to address three primary issues: GHG, Petroleum Use, and Air Quality. Vehicles must be ready for and affordable to the mass market to provide the customer choices to meet their transportation needs whether it is EV's, Hybrids, Plug-In Hybrids or Fuel Cell Hydrogen Hybrids. Our studies have shown that EVs have the potential to provide significant improvements in energy utilization especially combined with other advanced technologies. Toyota believes that a combination of these technolgies will provide complementary solution that enables a sustainable transportation system. Presenter Takehito Yokoo, Toyota Motor Corporation
Technical Paper

Development of Combustion Behavior Analysis Techniques in the Ultra High Engine Speed Range

2007-04-16
2007-01-0643
In order to clarify the combustion behavior in the ultra high engine speed range, a new technique has been developed. This technique is composed of ionization current detection and flame observation, and is highly heat-resistant, vibration-resistant, and has a quick response. From analyzing the flame front propagation in the high-speed research engine, it was found that the flame propagated throughout the entire cylinder over almost the same crank angle period irrespective of engine speed introduction.
Technical Paper

Development of an Engine Torque Estimation Model: Integration of Physical and Statistical Combustion Model

2007-04-16
2007-01-1302
Recent engine systems have become complex due to the requirements of fuel efficiency, exhaust gas emission control and good drivability. To decrease engine development period, model-based development has been adopted [1]. For torque-based vehicle control, engine torque estimation models are necessary. Simple mean-value torque models are available but these models require large amount of test data for development and validation. In addition, they cannot estimate transient torque precisely. On the other hand, complex physical models require considerable time for modeling and simulation. In order to decrease modeling time and retain model accuracy, the Wiebe function is utilized to calculate the heat release rate.
Technical Paper

Improvements in Low Temperature Diesel Combustion with Blending ETBE to Diesel Fuel

2007-07-23
2007-01-1866
The effects of blending ETBE to diesel fuel on the characteristics of low temperature diesel combustion and exhaust emissions were investigated in a naturally-aspirated DI diesel engine with large rates of cooled EGR. Low temperature smokeless diesel combustion in a wide EGR range was established with ETBE blended diesel fuel as mixture homogeneity is promoted with increased premixed duration due to decreases in ignitability as well as with improvement in fuel vaporization due to the lower boiling point of ETBE. Increasing the ETBE content in the fuel helps to suppress smoke emissions and maintain efficient smokeless operation when increasing EGR, however a too high ETBE content causes misfiring at larger rates of EGR. While the NOx emissions increase with increases in ETBE content at high intake oxygen concentrations, NOx almost completely disappears when reducing the intake oxygen content below 14 % with cooled EGR.
Technical Paper

Performance of Two/Four Stroke Gasoline HCCI Engine with Electromagnetic Valve Train

2007-07-23
2007-01-1868
Comparison of net thermal efficiency and emission in two and four stroke gasoline HCCI engine has been carried out for various valve-timings as negative valve overlap and exhaust valve double opening. The valve timings could easily be converted from a mode to another by configuring schedule of electromagnetic valve-train. Extension of operable torque with high thermal efficiency had been expected in two-stroke HCCI operation, however friction and supercharger loss curtailed about half of the gain in indicated thermal efficiency. In four-stroke operation modes, exhaust valve double opening (‘reinduction’ or ‘rebreathing’) showed the best net thermal efficiency and emission, however the extension of high load limit could not be achieved considerably.
Technical Paper

Development of High Fidelity Combustion-Driven Vehicle Models for Driveability Using Advanced Multi-Body Simulations

2007-04-16
2007-01-1634
This paper demonstrates the development of a full multi-body vehicle model and its use in virtual design and troubleshooting of a vehicle response to throttle input. The multibody model is divided into three main subsystems: the chassis, the driveline and the powertrain subsystems. The chassis system includes a complete representation of both the front and the rear suspensions, both the front and rear subframes, and the vehicle body. The driveline system includes the output shafts from the transmission unit to the tires. The powertrain system includes complete representation of the cranktrain for a V6 combustion engine. Also included in the powertrain is a nonlinear representation of the gearbox where bearing clearances and gear lashes are considered. The cranktrain torque output is linked to the transmission using a torque converter model. The vehicle components are virtually assembled together through different joint types, force elements, and kinematic constraints.
Technical Paper

Summary report of Japan Clean Air Program diesel and diesel fuel activities

2007-07-23
2007-01-1952
Diesel emissions are significant issue worldwide, and emissions requirements have become so tough that. the application of after-treatment systems is now indispensable in many countries To meet even more stringent future emissions requirements, it has become apparent that the improvement of market fuel quality is essential as well as the development in engine and exhaust after-treatment technology. Japan Clean Air Program II (JCAP II) is being conducted to assess the direction of future technologies through the evaluation of current automobile and fuel technologies and consequently to realize near zero emissions and carbon dioxide (CO2) emission reduction. In this program, effects of fuel properties on the performance of diesel engines and a vehicle equipped with two types of diesel NOx emission after-treatment devices, a Urea-SCR system and a NOx storage reduction (NSR) catalyst system, were examined.
Technical Paper

Study of Future Engine Oil (First Report): Future Engine Oil Scenario

2007-07-23
2007-01-1977
In recent years, problems such as global warming, the depletion of natural resources, and air pollution caused by emissions are emerging on a global scale. These problems call for efforts directed toward the development of fuel-efficient engines and exhaust gas reduction measures. As a solution to these issues, performance improvements should be achieved on the oil that lubricates the sliding sections of engines. This report points to features required of future engine oil-such as contribution to fuel consumption, minimized adverse effects on the exhaust gas aftertreatment system, and improved reliability achieved by sludge reduction-and discusses the significance of these features. For engine oil to contribution of engine oil to lower fuel consumption, we examined the effects of reduced oil viscosity on friction using gasoline and diesel engines.
Technical Paper

The Impact of RON on SI Engine Thermal Efficiency

2007-07-23
2007-01-2007
Recently, global warming and energy security have received significant attention. Thus an improvement of the vehicle fuel economy is strongly required. For engines, one effective way is to improve the engine thermal efficiency. Raising compression ratio [1] or turbo charging technologies have potential to achieve high thermal efficiency. However knock does not allow the high thermal efficiency. Knock depends on the fuel composition and the pressure and temperature history of unburnt end-gas [2-3]. For fuels, RON is well known for describing the anti knock quality. High RON fuels have high anti knock quality and result in higher thermal efficiency. This paper investigates the impact of high RON fuels on the thermal efficiency by using high compression ratio engine, turbo charged engine, and lean boosted engine [4]. Finally, it is shown that the high thermal efficiency can be approached with high RON gasoline and ethanol.
Technical Paper

GTL Fuel Impact on DI Diesel Emissions

2007-07-23
2007-01-2004
Reduction of exhaust emissions was investigated in a modern diesel engine equipped with advanced diesel after treatment system using a Gas-to-Liquid (GTL) fuel, a cleaner burning alternative diesel fuel. This fuel has near zero sulfur and aromatics and high cetane number. Some specially prepared GTL fuel samples were used to study the effects of GTL fuel distillation characteristics on exhaust emissions before engine modification. Test results indicated that distillation range of GTL fuels has a significant impact on engine out PM. High cetane number also improved HC and CO emissions, while these fuel properties have little effect on NOx emissions. From these results, it was found that low distillation range and high cetane number GTL fuel can provide a favorable potential in NOx/PM emissions trade-off. In order to improve the tail-pipe emissions in the latest diesel engine system, the engine modifications were carried out for the most favorable GTL fuel sample.
Technical Paper

High-pressure Metal Hydride Tank for Fuel Cell Vehicles

2007-07-23
2007-01-2011
High-pressure metal hydride (MH) tank has been designed based on a 35 MPa cylinder vessel. The heat exchanger module is integrated into the tank. Its advantage over high-pressure cylinder vessels is its large hydrogen storage capacity, for example 9.5 kg with a tank volume of 180 L by Ti25Cr50V20Mo5 alloy. Cruising range is about 900 km, over 3 times longer than that of a 35 MPa cylinder vessel system with the same volume. The hydrogen-charging rate of this system is equal to the 35 MPa cylinders without any external cooling facility. And release of hydrogen at 243 K is enabled due to the use of hydrogen-absorbing alloy with high-dissociation pressure, for example Ti35Cr34Mn31 alloy.
Technical Paper

Vegetable Oil Hydrogenating Process for Automotive Fuel

2007-07-23
2007-01-2030
From the viewpoint of primary energy diversification and CO2 reduction, interests of using Biomass Fuel are rising. Some kinds of FAME (Fatty Acid Methyl Ester), which are obtained from oil fats like vegetable oil using transesterification reaction with methanol, are getting Palm Oilpular for bio-diesel recently. In this study, we have conducted many experiments of palm oil hydrogenations using our pilot plants, and checked the reactivity and the pattern of product yields. As a result, we figured out that the hydrocarbon oil equivalent to the conventional diesel fuel can be obtained from vegetable oils in good yield under mild hydrogenation conditions. Moreover, as a result of various evaluations for the hydrogenated palm oil (oxidation stability, lowtemperature flow property, LCA, etc.), we found that the hydrogenated palm oil by our technology has performances almost equivalent to conventional diesel fuel.
Technical Paper

Investigations of Compatibility of ETBE Gasoline with Current Gasoline Vehicles II

2007-07-23
2007-01-2039
JCAPII gasoline workgroup reported vehicle emission study to comprehend the impact of ETBE blending. In previous study, we focused on the compatibility of ETBE blended gasoline with Japanese current gasoline vehicles in-use. Based on recent discussion with ETBE 8% blended gasoline into the market, more information becomes necessary. In this second report, we studied to comprehend the actual emission impact using realistic model fuels using several base stocks. Fuel properties of T50, T90 and aromatic compound content were selected through discussions. Specifications were changed within the range of the market. Both ETBE 0% and 8% were combined for these fuel matrixes. In total, eight fuels and two reference fuels were tested. Two J-ULEV vehicles (one MPI, and a stoichiometric-SIDI) were procured as representatives. We discussed quantitative and qualitative impact toward emissions. Data regarding CO2 and fuel economy change were also reported.
Technical Paper

High Concentration Ethanol Effect on SI Engine Cold Startability

2007-07-23
2007-01-2036
From the energy security and CO2 discharge reduction point of view, much attention has been paid to the usage of biofuel, ethanol, as an alternative source of energy in the transportation industry. Yet, the major drawback in applying highly concentrated ethanol in the spark ignited internal combustion engines is cold start instability. This is due to the characteristics of ethanol, large latent heat required to vaporize. This paper investigates necessary conditions for the engine cold start, using highly concentrated ethanol. Tests performed with varieties of ethanol fuel, a relationship between cold startability lower temperature limit and reid vapor pressure was observed. A method to boost the vaporization, intake valve timing control is introduced to obtain high compression peak temperature.
Technical Paper

Feasibility Study of Ethanol Applications to A Direct Injection Gasoline Engine

2007-07-23
2007-01-2037
Feasibility studies concerning ethanol utilization in direct injection gasoline engines were conducted in order to clarify the effects of ethanol on engine performance, exhaust emissions and injector deposit formation. The investigation results indicate that E100 (100% ethanol fuel) can improve full load engine performance around whole engine speed range in a high compression ratio engine (ε=13:1), compared to that of a base compression ratio engine (ε=11.5:1) operated on a premium gasoline. This was caused by the volumetric efficiency (ηv) improvement and engine knock suppression in the high compression ratio engine. On the other hand, HC emissions remarkably increased under lower engine speeds at a full load condition. This phenomenon suggests that poor combustion occurred due to insufficient mixing of air and E100 fuel under these conditions, in which the amount of ethanol injected was too large and fluidity in the cylinder was weak.
Technical Paper

Experimental Analysis of Acoustic Coupling Vibration of Wheel and Suspension Vibration on Tire Cavity Resonance

2007-05-15
2007-01-2345
It is difficult to improve tire cavity noise since the pressure of cavity resonance acts as a compelling force, and its low damping and high gain characteristics dominate the vibration of both the suspension and body. For this reason, the analysis described in this article aimed to clarify the design factors involved and to improve this phenomenon at the source. This was accomplished by investigating the acoustic coupling vibration mode of the wheel, which is the component that transmits the pressure of cavity resonance at first. In addition, the vibration characteristic of suspension was investigated also. A speaker-equipped sound pressure generator inside the tire and wheel assembly was developed and used to infer that wheel vibration under cavity resonance is a forced vibration mode with respect to the cavity resonance pressure distribution, not an eigenvalue mode, and this phenomenon may therefore be improved by optimizing the out-of-plane torsional stiffness of the disk.
Technical Paper

Combustion Analysis on Piston Cavity Shape of a Gasoline Direct Injection Engine

2001-05-07
2001-01-2029
This paper describes the analyses to improve both stratified and homogeneous charge combustion of a gasoline direct injection engine. In this study, computational fluid dynamics (CFD) and high-speed hydrocarbon (HC) measurement were employed to observe the mixture formation process. The analysis of the combustion flame propagation was conducted by in-cylinder visualization and ion current measurement. As a result of the analyses, the following conclusions were made: 1 An oval shaped wall cavity can direct the mixture gas to the vicinity of the spark plug better than a conventional shell-shaped wall cavity. The oval shaped wall cavity can improve fuel consumption and HC emission at stratified charge combustion. 2 A shallow cavity improves the homogenization of mixture gases and wide open throttle (WOT) performance.
Technical Paper

Oxidation Stability of Automatic Transmission Fluids -A Study by the International Lubricants Standardization and Approval Committee (ILSAC) ATF Subcommittee

2001-05-07
2001-01-1991
The International Lubricant Standardization and Approval Committee (ILSAC) ATF subcommittee members have compared the two oxidation bench test methods, Aluminum Beaker Oxidation Test (ABOT) and Indiana Stirring Oxidation Stability Test (ISOT), using a number of factory-fill and service-fill ATFs obtained in Japan and in the US. In many cases, the ATFs were more severely oxidized after the ABOT procedure than after the same duration of the ISOT procedure. The relative severity of these two tests was influenced by the composition of the ATFs. The bench test oxidation data were compared with the transmission and the vehicle oxidation test data.
Technical Paper

Noise and Vibration Reduction Technology in Hybrid Vehicle Development

2001-04-30
2001-01-1415
The world's first mass production gasoline hybrid passenger car, the “Prius”, was introduced into the Japanese market in 1997. By the time it was introduced into the American and European markets in Mid-2000, its fuel consumption and exhaust emissions had been further improved while achieving superior NV performance compared with conventional vehicles with 1.5-liter engines even in these competitive markets. This paper describes NV reduction technology for problems peculiar to the hybrid vehicle such as engine start/stop vibration, drone noise and vibration at low engine speed and motor/generator noise and vibration. It also compares the overall NV performance of the hybrid vehicle with conventional gasoline engine vehicles.
Technical Paper

Development of “Virtual and Real Simulator” for Engine

2001-03-05
2001-01-1355
We developed a progressive system, “virtual and real simulator (V&R-S)” for engine. To innovate the process of engine development, the test system creates dynamic load of drivetrain, wheel, body and road with the virtual vehicle model. We set the phenomena such as drivetrain vibration for reproducing object of this system. The load is transmitted to the engine crankshaft end as torque with the connecting shaft made of fiberglass. The mainly developed technologies are the dynamometer with rotational inertia as low as engine, correction method of transmitted torque error of connecting shaft by H-infinity control. Thanks to these, we achieved the capability of optimization for most of dynamic characteristics (emission, fuel consumption, drivability) on engine test bench. And we now be able to limit real vehicle test to the final tuning. As a result, we have realized new engine evaluation and optimization process.
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