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Video

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
Video

A Study of PGM-Free Oxidation Catalyst YMnO3 for Diesel Exhaust Aftertreatment

2012-06-18
Manganese oxides show high catalytic activity for CO and HC oxidation without including platinum group metals (PGM). However, there are issues with both thermal stability and resistance to sulfur poisoning. We have studied perovskite-type YMnO3 (YMO) with the aim of simultaneously achieving both activity and durability. This paper describes the oxidation activity of PGM-free Ag/i-YMO, which is silver supported on improved-YMO (i-YMO). The Ag/i-YMO was obtained by the following two methods. First, Mn4+ ratio and specific surface area of YMO were increased by optimizing composition and preparation method. Second, the optimum amount of silver was supported on i-YMO. In model gas tests and engine bench tests, the Ag/i-YMO catalyst showed the same level of activity as that of the conventional Pt/?-Al2O3 (Pt = 3.0 g/L). In addition, there was no degradation with respect to either heat treatment (700°C, 90 h, air) or sulfur treatment (600°C to 200°C, total 60 h, 30 ppm SO2).
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

A Molecular Dynamics Analysis of the Traction Fluids

2007-04-16
2007-01-1016
Non-equilibrium all-atom MD simulations are used to study the traction properties of hydrocarbon fluids. A fluid layer is confined between two solid Fe plates under the constant normal force of 1.0 GPa. Traction simulations are performed by applying a relative sliding motion to the Fe plates. Shear behaviors of nine hydrocarbon fluids are simulated on a sufficiently large film thickness of 6.7 nm, and succeeded in reproducing the order of the experimental traction coefficients. The dynamic mechanism of the momentum transfer on layers of fluid molecules are analyzed focusing on the intermolecular interactions (density profile, orientation factor, pair-correlation function) and intramolecular interactions (intramolecular interaction energy, conformation change of alicyclic ring). In contrast to the case of n-hexane, which shows low traction due to a fragile chain-like interaction, other mechanisms are obtained in the high traction molecules of cyclohexane, dicyclohexyl and santotrac 50.
Technical Paper

Liquid Phase Thermometry of Common Rail Diesel Sprays Impinging on a Heated Wall

2007-07-23
2007-01-1891
An experimental study was carried out on visualization of liquid phase temperature distributions in high-pressure diesel sprays impinging on a heated wall. Naphthalene/TMPD-exciplex fluorescence method and pyrene-excimer fluorescence method were utilized for the thermometry. The sprays were injected into a high-pressure and high-temperature gaseous environment. The nozzle hole diameter was 0.100 mm or 0.139 mm. The results showed that cool pockets were formed at the tip and in the impinging part of the sprays. The spray for the nozzle with 0.100 mm hole was heated up faster near the nozzle than for the nozzle with 0.139 mm hole.
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

Improvement of DI Diesel Engine System by Utilizing GTL Fuels Characteristics

2009-06-15
2009-01-1933
Gas To Liquid (GTL) fuels synthesized from natural gas are known as clean fuels. Therefore, GTL fuels have been expected to be a promising option that can reduce the NOx and PM emissions from diesel engines and contribute to the energy security. In this study, in order to clarify the emission reduction potentials, the improvement of DI diesel engine and aftertreatment systems were investigated by utilizing GTL fuels characteristics. To achieve a further reduction of both NOx and PM emissions, the combustion chamber, injection pattern and EGR calibration were modified. From the results of tests, the engine out NOx emissions were reduced to the Euro 6 regulation level and in parallel the expected deteriorations of HC emission and fuel consumption were suppressed because of the characteristics of high cetane number and zero poly-aromatics hydrocarbons. Additionally, an aftertreatment system was optimized to GTL fuel in order to improve NOx conversion efficiency.
Technical Paper

Development of Double-Layered Three-Way Catalysts

2009-04-20
2009-01-1081
It is critical to develop high performance three-way catalysts to meet increasing regulations around the world. It was found that a double-layered catalyst loaded with Pt and Rh suppresses Pt-Rh alloying, thereby improving catalytic performance. A double-layered catalyst has the effect of decreasing OSC performance, but this has been overcome by a newly developed Rh support and suppressed Pt grain growth. The developed catalyst is capable of lowering the amount of PGM required by approximately 40%.
Technical Paper

Study of Large OSC Materials (Ln2O2SO4) on the Basis of Sulfur Redox Reaction

2009-04-20
2009-01-1071
Three-way catalyst shows high performance under stoichiometric atmosphere. The CeO2-ZrO2 based materials (CZ) are added as a buffer of O2 concentration. To improve the catalyst performance the larger O2 storage capacity (OSC) are needed. Theoretically, the sulfur oxidation-reduction reaction moves oxygen 8 times larger than cerium. We focused on this phenomenon and synthesized Ln2O2SO4 as a new OSC material. The experimental result under model gas shows that the OSC of Ln2O2SO4 is 5 times lager than CZ.
Technical Paper

Development of Fuel Cell Hybrid Vehicle by Toyota -Durability-

2009-04-20
2009-01-1002
Various issues must be resolved before sustainable mobility can be achieved, the most important of which are reacting to energy supply and demand, and lowering CO2 emissions. At present, the fact that the vast majority of vehicles run on conventional oil is regarded as a problem for which Toyota Motor Corporation (TMC) is developing various technological solutions. Fuel cell (FC) technology is one of the most promising of these solutions. A fuel cell is an extremely clean device that uses hydrogen and oxygen to generate power without emitting substances like CO2, NOx, or PM during operation. Its energy efficiency is high and it is widely expected to form the basis of the next generation of powertrains. Since 1992, TMC has been working to develop the main components of fuel cell vehicles, including the fuel cell itself, and the high pressure hydrogen tank and hybrid systems.
Technical Paper

Development of a 6-Cylinder Gasoline Engine with New Variable Cylinder Management Technology

2008-04-14
2008-01-0610
Aiming for higher output power, greater fuel economy and reduced exhaust emissions, a new V-6 3.5-liter i-VTEC Variable Cylinder Management (VCM) engine has been developed. This engine uses a cylinder-deactivation mechanism with VTEC technology that allows the number of cylinders to be controlled in three modes (three, four or all six cylinders), according to the operating conditions. This adds a four-cylinder mode to the conventional cylinder- deactivation engine. In addition to increasing the number of cylinder- deactivation modes, the new hydraulic circuits, a hydraulic pressure switching mechanism and a switchover control were also developed. These make it possible to instantaneously switch the active cylinders without impairing drivability, in the same manner as a conventional engine.
Technical Paper

Study on the Potential Benefits of Plug-in Hybrid Systems

2008-04-14
2008-01-0456
There is ever increasing interest in the issues of fossil fuel depletion, global warming, due to increased atmospheric CO2, and air pollution, all of which are due in some extent to transportation, including automobiles. Hybrid Vehicles (HVs), whose performance and usage are equivalent to existing conventional vehicles, attract lots of attention and have started to come into wider use. Meanwhile, EVs have been considered by many as the best solution for the issues mentioned above. But the technical difficulty of battery energy density is an obstruction to successful implementation. Currently the Plug-in HV (PHEV), which combines the advantages of HV and EV, is being considered as one promising solution. PHEVs can be categorized into two types, according to operating modes. The first uses battery stored energy initially, only stating the internal combustion engine when the battery is depleted. This we call the All Electric Range (AER) system.
Technical Paper

Newly Developed Toyota Plug-in Hybrid System and its Vehicle Performance under Real Life Operation

2011-06-09
2011-37-0033
Toyota has been introducing several hybrid vehicles (HV) since 1997 as a countermeasure to the concerns raised by automobile, like CO2 reduction, energy security, and pollutant emission reduction in urban areas. Plug in hybrid Vehicle (PHV) uses electric energy from grid rather than fuel for most short trips and therefore presents a next step forward towards an even more effective solution for these concerns. For longer trips, the PHV works as a conventional hybrid vehicle, providing all the benefits of Toyota full hybrid technology, such as low fuel consumption, user-friendliness and long cruising range. This paper describes a newly developed plug-in hybrid system and its vehicle performance. This system uses a Li-ion battery with high energy density and has an EV-range within usual trip length without sacrificing cabin space.
Technical Paper

A Study of High Power Output Diesel Engine with Low Peak Cylinder Pressure

2010-04-12
2010-01-1107
This study examined a high-speed, high-powered diesel engine featuring a pent-roof combustion chamber and straight ports, with the objective of improving the specific power of the engine while minimizing any increase in the maximum cylinder pressure (Pmax). The market and contemporary society expect improvements in the driving performance of diesel-powered automobiles, and increased specific power so that engine displacement can be reduced, which will lessen CO2 emissions. When specific power is increased through conventional methods accompanied with a considerable increase in Pmax, the engine weight is increased and friction worsens. Therefore, the authors examined new technologies that would allow to minimize any increase in Pmax by raising the rated speed from the 4000 rpm of the baseline engine to 5000 rpm, while maintaining the BMEP of the baseline engine.
Journal Article

Development of Waterborne Conductive Primer for Motorcycles

2012-10-23
2012-32-0089
Most types of paint materials currently used for motorcycles contain large amounts of VOCs (Volatile Organic Compounds). VOCs are environmental load substances, and there is a demand to reduce emissions in recent years. Many of a motorcycle's exterior parts are made of ABS (Acrylonitrile-Butadiene-Styrene) plastics (henceforth ABS) or PA (Polyamid) plastics (henceforth PA). These two plastic materials have different film adhesion mechanisms and adhesion strength. Therefore it was necessary to use different conductive primers and that's was one of the factors which made time and material losses in the painting processes. We solved those two issues, the reduction of VOCs and the common use of the same conductive primer for different parts materials, by combining two kinds of resins originally designed as the conductive primers, i.e., urethane resins with carboxylic acid groups and acrylic resins with amide groups, which are different in properties.
Technical Paper

Development of Low Pressure Loop EGR System for Diesel Engines

2011-04-12
2011-01-1413
Low pressure loop (LPL) EGR systems are effective means of simultaneously reducing the NOx emissions and fuel consumption of diesel engines. Further lower emission levels can be achieved by adopting a system that combines LPL EGR with a NOx storage and reduction (NSR) catalyst. However, this combined system has to overcome the issue of combustion fluctuations resulting from changes in the air-fuel ratio due to EGR gas recirculation from either NOx reduction control or diesel particulate filter (DPF) regeneration. The aim of this research was to reduce combustion fluctuations by developing LPL EGR control logic. In order to control the combustion fluctuations caused by LPL EGR, it is necessary to estimate the recirculation time. First, recirculation delay was investigated. It was found that recirculation delay becomes longer when the LPL EGR flow rate or engine speed is low.
Journal Article

Introduction of New Concept U*sum for Evaluation of Weight-Efficient Structure

2011-04-12
2011-01-0061
A new index U* for evaluating load path dispersion is proposed, using a structural load path analysis method based on the concept of U*, which expresses the connection strength between a load point and an arbitrary point within the structure. U* enables the evaluation of the load path dispersion within the structure by statistical means such as histograms and standard deviations. Different loading conditions are applied to a body structure, and the similarity of the U* distributions is evaluated using the direction cosine and U* 2-dimensional correlation diagrams. It is shown as a result that body structures can be macroscopically grasped by using the U* distribution rather than using the stress distribution. In addition, as an example, the U* distribution of torsion loading condition is shown to comprehensively include characteristics of the U* distribution of other loading conditions.
Technical Paper

Feasibility Study of Exhaust Emissions in a Natural Gas Diesel Dual Fuel (DDF) Engine

2012-09-10
2012-01-1649
The Diesel Dual Fuel (DDF) vehicle is one of the technologies to convert diesel vehicles for natural gas usage. The purpose of this research was to study the possibility of a DDF vehicle to meet emission standards for diesel vehicles. This research was done for small passenger vehicles and commercial vehicles. The exhaust emissions compliance of such vehicles in a New European Driving Cycle (NEDC) mode which was composed of Urban Driving Cycles (UDC) and an Extra Urban Driving Cycle (EUDC) was evaluated. (see APPENDIXFigure A1) In this study, the passenger vehicle engine, compliant with the EURO4 standard, was converted to a DDF engine. Engine bench tests under steady state conditions showed similar result to previous papers. Total hydrocarbon (HC) emission was extremely high, compared to diesel engine. The NEDC mode emissions of the DDF vehicle were estimated based on these engine bench test results.
Technical Paper

A Modeling and Experimental Investigation on an Innovative Substrate for DPF Applications

2010-04-12
2010-01-0891
XP-SiC is an innovative type of a porous substrate material on the basis of a reaction formed SiC for DPF applications. The high porosity, large pore size inside the cell wall and low specific weight are the special characteristics of this substrate. The aim of the current paper is to present an investigation based on the experimental and modeling approaches to evaluate the back pressure, filtration efficiency and the thermal durability. The latter one was assessed by measuring and predicting the temperature field, as well as calculating the thermal stresses. For this purpose the filter was modeled in the commercial computational code axitrap as a stand-alone tool, in which the conservation equations of mass continuity, momentum, energy and species were solved. The soot filtrations, loading as well as the regeneration by fuel-borne catalyst were modeled.
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.
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