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Technical Paper

Analysis of car structures in future market and necessary policy for environment based on the vehicle performance and economic aspects

2000-06-12
2000-05-0382
Increasing CO2 emissions from vehicles is becoming a major concern in automotive society, and variety of future types of cars are intensively investigated. However it is not clear which level of performance and cost must be achieved for the future cars to be available in a market and how much percentage of cars is necessary to be replaced by the future cars for the conservation of environment. The objective of this paper is to evaluate the possibility of market growth of future cars, as hybrid cars, electric vehicles and fuel cell cars, based on the performance and economic aspects. This paper investigates the emission reduction potential of these vehicles, and also compares the composition of vehicle types and emissions for a variety of scenarios of consumer characteristics, economic growth, fuel price, performance of cars, and carbon tax control measures. A model of user preference of cars was established from the statistic analysis of past data.
Technical Paper

New Four Valves Per Cylinder Basic Engine for Passenger Car

1987-11-08
871177
Through the experience in developing several 4-valve sporty engines, we have had an idea that 4-valve technology regarded as one of sporty engines may be applied to a standard engine of a passenger car. Making use of the superior characteristics of 4-valve technology, combustion chamber design and valve train system were completely refined for a standard engine. Higher torque in low to middle speed range and good fuel economy, important features in practical use, were pursued as the prior target of development. As a passenger car engine, comfortable sound in passenger compartment is an important feature as well as high performance and good fuel economy. With these concepts, we have developed the 3S-FE, 2-liter, 4-valve engine which has achieved 5.1& torque, 18.6% horse power and 9.7% Fuel consumption (highway mode) gains compared with the original 2S-E, 2-liter, 2-valve engine.
Technical Paper

Poisoning Deactivations of Automotive Catalysts by Lead and Phosphorus

1985-11-11
852219
The deactivation process of automotive catalysts by lead and phosphoruos were studied. The accelerated poisoning test were performed. The activity evaluation and characterisation of poisoned pellet oxidation catalysts showed the following origin of poisoning deactivations. Lead interacts with active materials and phosphorus covers over catalysts to reduce these catalytic performance. In the case of phosphorus and lead co-existence, the activity decreases rapidly because leadphosphate plugges pores of the support. In monolithic catalysts, highly axial distributions of poisons was obserbed. This characteristic distribution is advantageous for the durability of the catalyst.
Technical Paper

Carbon Dioxide Measuring Technology in Engine Combustion Chambers

2004-03-08
2004-01-1340
The authors have developed an instrument that measures the CO2 concentration in engine combustion chambers using the infrared absorption method. The characteristics of this technology are as follows: 1 Measuring can be carried out while the engine is running at 600r/min to more than 3000r/min, full load operation. (Applicable to all EGR conditions) 2 Quick response; 2ms 3 High linearity; ±1% Full Scale and under (FS: 10%) 4 No aggravation is caused to the intake/exhaust performance of engines This technology contributes to the improvement of the in-cylinder EGR system using, for instance, a variable valve-timing mechanism that is now expanding in number of applications, and also the conventional EGR system.
Technical Paper

Development of New Hybrid System for Compact Class Vehicles

2009-04-20
2009-01-1332
Toyota has been evolving a hybrid system since introducing the first mass-production hybrid vehicle in 1997 in response to the increasing automotive-related issues of CO2 emissions, energy security, and urban air pollution. This paper describes a newly developed hybrid system design and its performance. This system was developed with the main purpose to improve fuel consumption, especially for better real world fuel consumption; and to enhance its compatibility with multiple vehicle adoption by downsizing and reducing the weight of its components. At the same time, the hybrid system achieved improved power performance while satisfying stringent emission regulations in the world.
Technical Paper

Quantitative Analysis of the Relation between Flame Structure and Turbulence in HCCI Combustion by Two-Dimensional Temperature Measurement

2008-04-14
2008-01-0061
The structure of HCCI (homogeneous charge compression ignition) combustion flames was quantitatively analyzed by measuring the two-dimensional gas temperature distribution using phosphor thermometry. It was found from the relation between a turbulent Reynolds number and Karlovitz number that, when compared with the flame propagation in an S.I. engine, HCCI combustion has a wider flame structure with respect to the turbulence scale. As a result of our experimentation for the influence of low temperature reaction (LTR) using two types of fuel, it was also confirmed that different types of fuel produce different histories of flame kernel structure.
Technical Paper

An Investigation on the Simultaneous Reduction of Particulate and NOx by Controlling Both the Turbulence and the Mixture Formation in DI Diesel Engines

1993-10-01
932797
This paper presents experimental results of the reduction of both particulate and NOx emitted from direct injection diesel engines by a two stage combustion process. The primary combustion is made very rich to reduce NOx and then the particulate is oxidized by strong turbulence generated during the secondary combustion. The rich mixture is formed by low pressure fuel injection and a small cavity combustion chamber configuration. The strong turbulence is generated by a jet of burned gas from an auxiliary chamber installed at the cylinder head. The results showed that NOx was reduced significantly while maintaining fuel consumption and particulate emissions. An investigation was also carried out on the particulate reduction process in the combustion chamber with the turbulence by gas sampling and in-cylinder observation with an optical fiber scope and a high speed camera.
Technical Paper

New Technology for Reducing the Power Consumption of Electrically Heated Catalysts

1994-03-01
940464
A new heating strategy for electrically heated catalysts has been developed which reduces power consumption while achieving the desired hydrocarbon conversion. The relationship between catalyst volume and power consumption is presented. Observations of catalytic reactions by a thermoviewer camera and mathematical simulations are used to optimize the heating pattern. Significant reductions in power consumption, while maintaining conversion efficiency, are reported by heating only the front face of the catalyst. However, prior to mass production additional work is required to improve durability, and reliability and to resolve manufacturing issues.
Technical Paper

Development of Three-Way Catalyst with Using Only Pd as Activator

1995-02-01
950257
The Pd only three-way catalyst with Rh as an activator completely removed has been developed. The catalyst has been improved with regards to its thermal stability and its NOx reduction capability in the fuel rich region. These two factors have been known as the weak points of Pd catalyst. The thermal stability of the Pd catalyst was improved by modifying the washcoat alumina to yield a higher thermal stability. On the other hand, the NOx reduction capability was controlled by adding a combination of La and Ba. The developed Pd only three-way catalyst demonstrated the equivalent performance to a current production Pt/Rh catalyst after engine dynamometer aging up to 800°C.
Technical Paper

Development of New Concept Three-Way Catalyst for Automotive Lean-Burn Engines

1995-02-01
950809
A new 3-way catalyst with NOx conversion performance for lean-burn engines has been developed. The catalyst oxidizes NOx and stores the resulting nitrate, which is then reduced by HC and CO during engine operation around the stoichiometric air/fuel ratio. Both the composition of the storage component and the particle sizes of the noble metal were optimized. In addition, a special air fuel mixture control has been developed to make the best of the NOx storage-reduction function. The present catalyst showed 90% conversion efficiency and improved fuel economy by 4% in the Japanese 10-15 mode test cycle. The efficiency remained at 60% or more after durability test.
Technical Paper

New Light Weight 3 Liter V6 Toyota Engine with High Output Torque, Good Fuel Economy and Low Exhaust Emission Levels

1995-02-01
950805
A new generation 3.0 liter V6 engine, the 1MZ-FE, has been developed. Through improvement of the basic technical characteristics of each individual component, the 1MZ-FE has achieved compactness, weight reduction and good fuel economy without adding systems or components. This new engine makes use of an aluminum cylinder block, and compared with the previous V6 engine, significant weight reduction of the crankshaft, connecting rods and pistons was achieved while still maintaining a high level of rigidity. To improve fuel economy, friction loss was reduced substantially by reducing the weight of moving parts and improving the surface roughness of sliding parts. The combustion was also improved through better fuel atomization by the air-assisted fuel injector and modification of the combustion chamber shape. Through these improvements the 1MZ-FE has achieved a weight reduction of approximately 20% and far greater vehicle fuel economy than before.
Journal Article

Development of Exhaust and Evaporative Emissions Systems for Toyota THS II Plug-in Hybrid Electric Vehicle

2010-04-12
2010-01-0831
Exhaust and evaporative emissions systems have been developed to match the characteristics and usage of the Toyota THS II plug-in hybrid electric vehicle (PHEV). Based on the commercially available Prius, the Toyota PHEV features an additional external charging function, which allows it to be driven as an electric vehicle (EV) in urban areas, and as an hybrid electric vehicle (HEV) in high-speed/high-load and long-distance driving situations. To reduce exhaust emissions, the conventional catalyst warm up control has been enhanced to achieve emissions performance that satisfies California's Super Ultra Low Emissions Vehicle (SULEV) standards in every state of battery charge. In addition, a heat insulating fuel vapor containment system (FVS) has been developed using a plastic fuel tank based on the assumption that such a system can reduce the diffusion of vapor inside the fuel tank and the release of fuel vapor in to the atmosphere to the maximum possible extent.
Journal Article

High Concentration Ethanol Effect on SI Engine Emission

2010-04-12
2010-01-1268
From the energy security and CO2 reduction point of view, much attention has been paid to the usage of bio-fuel. Recently, highly concentrated ethanol is used in some areas (“E85”; 85% ethanol and 15% gasoline in North America and Sweden, and “ethanol”; 93% ethanol and 7% water in Brazil). In these regions, Flexible Fuel Vehicles FFVs are being introduced that are capable of using fuels with a wide range of ethanol concentrations. Advantages of highly concentrated ethanol in internal combustion engine applications are higher thermal efficiency obtained due to higher octane number, and a reduction of nitrogen oxides due to lower combustion temperatures On the other hand, the latent heat of vaporization for ethanol is greater than gasoline, causing poor cold startability and high NMOG emissions. This paper examines the effect of highly concentrated ethanol on exhaust emissions at cold start in a SI- engine.
Technical Paper

Development of High-Strength Aluminum Piston Material

2010-04-12
2010-01-0220
Mass reduction of parts is growing in importance as a means for reducing CO2 emissions from vehicles.The aim of the present research was to contribute to further mass reduction of pistons by developing a new aluminum casting material with highest level of fatigue strength. This goal was achieved using a development concept of creating a homogeneous structure in which Ti was added to create a fine structure and appropriate quantities of Fe and Mn were added to form a compound that is stable at high temperatures. Stand-alone tests of prototype pistons fabricated using the developed material show that the material is 14% stronger than the conventional material, thereby enabling increases in power and mass reduction.
Journal Article

Development of Clean Diesel NOx After-treatment System with Sulfur Trap Catalyst

2010-04-12
2010-01-0303
Diesel engines with relatively good fuel economy are known as an effective means of reducing CO₂ emissions. It is expected that diesel engines will continue to expand as efforts to slow global warming are intensified. Diesel particulate and NOx reduction system (DPNR), which was first developed in 2003 for introduction in the Japanese and European markets, shows high purification performance which can meet more stringent regulations in the future. However, it is poisoned by sulfur components in exhaust gas derived from fuel and lubricant. We then developed the sulfur trap DPNR with a sulfur trap catalyst that traps sulfur components in the exhaust gas. High purification performance could be achieved with a small amount of platinum group metal (PGM) due to prevention of sulfur poisoning and thermal deterioration.
Journal Article

Simultaneous Reduction of NOx and PM in Diesel Exhaust Based on Electrochemical Reaction

2010-04-12
2010-01-0306
The emission regulations for diesel engines are continually becoming stricter to reduce pollution and conserve energy. To meet these increasingly stringent regulations, a new exhaust after-treatment device is needed. Recently, the authors proposed the simultaneous electrochemical reduction (ECR) system for diesel particulate matter (PM) and NOx. In this method, a gas-permeable electrochemical cell with a porous solid oxide electrolyte is used for PM filtering on the anode. Alkaline earth metal is coated on the cathode for NOx storage. Application of voltage to both electrodes enables the simultaneous reduction of PM and NOx by the forced flow of oxygen ions from the cathode to the anode (oxygen pumping). In this study, the basic characteristics of the ECR system were investigated, and a disk-shaped electrochemical cell was evaluated.
Technical Paper

Development of Rheologically Controlled Waterborne Basecoats

1999-03-01
1999-01-1208
Public awareness toward the environment has been increasing recently. Accordingly, volatile organic compounds from automotive coating processes must be decreased to protect the environment. Various environmental regulations are already being enforced in many countries and it's expected that the rules will become tighter every year. For this reason, the usage of waterborne basecoats has increased recently. But the introduction of waterborne basecoats has some difficulties such as the requirement of strict temperature and humidity control. So, the application of waterborne basecoats has been inferior to that of solventborne basecoats. We have conducted an investigation, putting emphasis on the viscosity characteristics of waterborne basecoats and reached the conclusion that the following factors are important for applying waterborne basecoats: During spray application, the paint indicates shear thinning behavior.
Technical Paper

Development of NOx Storage-Reduction Three-way Catalyst for D-4 Engines

1999-03-01
1999-01-1279
It is an essential task for automobiles to reduce their fuel consumption. A direct injection gasoline engine (D-4 engine) is effective in reducing fuel consumption, but the reduction of NOx in the lean combustion region is impossible with a conventional three-way catalyst. The NOx storage-reduction three-way catalyst was put into practical use in 1994 for vehicles with lean-burn engines. This catalyst, however, is poisoned by SO2 caused by fuel sulfur, thus its activity is reduced. The conversion efficiency of this sulfur poisoned catalyst was not sufficient for reducing NOx in the exhaust gas of D-4 engine. We have, therefore, studied the mechanism of sulfur poisoning, and succeeded in improving the catalytic performance with the newly developed monolithic substrate and the newly developed additives.
Journal Article

Combustion Characteristics of Emulsified Blends of Water and Diesel Fuel in a Diesel Engine with Cooled EGR and Pilot Injection

2013-10-15
2013-32-9022
Water and diesel fuel emulsions containing 13% and 26% water by volume were investigated in a modern diesel engine with relatively early pilot injection, supercharging, and cooled EGR. The heat release from the pilot injection with water emulsions is retarded toward the top dead center due to the poor ignitability, which enables larger pilot and smaller main injection quantities. This characteristic results in improvements in the thermal efficiency due to the larger heat release near the top dead center and the smaller afterburning. With the 26% water emulsion, mild, smokeless, and very low NOx operation is possible at an optimum pilot injection quantity and 15% intake oxygen with EGR at or below 0.9 MPa IMEP, a condition where large smoke emissions are unavoidable with regular unblended diesel fuel. Heat transfer analysis with Woschni's equation did not show the decrease in cooling loss with the water emulsion fuels.
Journal Article

Influence of Fuel Properties on Operational Range and Thermal Efficiency of Premixed Diesel Combustion

2013-10-15
2013-32-9054
The influence of fuel properties on the operational range and the thermal efficiency of premixed diesel combustion was evaluated with an ordinary diesel fuel, a primary reference fuel for cetane numbers, three primary reference fuels for octane numbers, and two normal heptane-toluene blend fuels in a single-cylinder DI diesel engine. The fuel injection timing was set at 25°CA BTDC and the maximum rate of pressure rise was maintained below 1.0 MPa/°CA when lowering the intake oxygen concentration by cooled EGR. With increasing octane numbers, the higher intake oxygen concentration can be used, resulting in higher indicated thermal efficiency due to a higher combustion efficiency. The best thermal efficiency at the optimum intake oxygen concentration with the ordinary diesel fuel is lower than with the primary reference fuels with the similar ignitability but higher volatility.
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