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Technical Paper

Thin wall and lightweight cylinder block production technology

2000-06-12
2000-05-0067
The automobile industry currently faces many challenges which may greatly impact on its foundry operations. One of these challenges, consumers'' demand for greater fuel efficiency, can be met by reducing the weight of castings used in automobiles, and minimizing engineering tolerances. In answer to this particular demand, engine foundries have begun to either produce cylinder blocks or other castings with aluminum rather than cast iron. However, if a reduction in weight (thin wall and near-net shaping) can be realized with cast iron, there would be numerous merits from the perspective of cost and compactness and there would be much more flexibility in automotive parts design.
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

Wear Mechanisms of Methanol Fueled Engine

1985-11-11
852199
The wear mechanisms of the methanol engine were studied using dynamometer tests. Formic acid from methanol combustion mixes with the lubricant oil and attacks the metal surfaces. The iso tacho prorissis method was successfully applied to analyze the formic acid content of the used oil. A large amount of condensed water is also formed by methanol combustion and accelerates the wear. Wear can be effectively reduced by shortening lubricant oil change intervals, by using a special oil and by durable surface treatment of engine parts.
Technical Paper

Toyota's New Six-Speed Automatic Transmission AB60E for RWD Vehicles

2007-04-16
2007-01-1098
Toyota Motor Corporation has developed a new six-speed automatic transmission AB60E for longitudinal front engine rear wheel drive (RWD) vehicles. This transmission development was aimed at an improvement of power performance and fuel economy, while achieving a lightweight, compact package and a high torque capacity. In order to achieve this target, a high-capacity ultra-flat torque converter, a highly-rigid transmission case, and an ATF warmer with a valve to switch ATF circuits to an air-cooled ATF cooler have been newly developed. Moreover, a new transmission mode control logic “TOW / HAUL” has been developed to improve power performance and driveability during trailer towing. This automatic transmission has adopted the same gear train and hydraulic control system as the conventional six-speed automatic transmission A760E. This paper describes the structure, major features and performance of the transmission in detail.
Technical Paper

Two-Dimensional Temperature Measurements in Engine Combustion Using Phosphor Thermometry

2007-07-23
2007-01-1883
A phosphor thermometry, for measurements of two-dimensional gas-phase temperature was examined in turbulent combustion in an engine. The reasonable temperature deviation and the agreement with calculated data within 5% precision were achieved by single-shot images in the ignition process of compression ignition engine. Focusing on the local flame kernel, the flame structure could be quantitatively given by the temperature. It became evident that the HCCI flame kernels had 1-3 mm diameter and the isolated island structures. Subsequently, the HTR zone consisted of the combined flame kernels near TDC.
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

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

Study of Anti-Corrosive Property of Engine Coolant for Aluminum Cylinder Heads

1995-02-01
950119
Recently, use of aluminum engine parts has increased for fuel economy and power improvements. Aluminum cylinder heads, for example, are currently used in most engines. But, only low performance engine coolants are available for prevention of heat-transfer corrosion of aluminum cylinder heads. The authors have studied a laboratory test method that is able to accurately evaluate the performance of engine coolants for prevention of aluminum cylinder head corrosion. And we have developed the new test method by changing the test specimen temperature higher and the engine coolant temperature lower than the ASTM D4340 test. The new test has been confirmed engine bench test. We evaluated further the performance of many engine coolants of the world for prevention of aluminum cylinder head corrosion using the new test. We have known that there were a lot of poor performance engine coolants in the world.
Technical Paper

Torque Converter Clutch Slip Control System

1995-02-01
950672
The torque converter clutch slip control system adopted in the Toyota A541E automatic transaxle engages the torque converter clutch by applying a steady slip speed to prevent the torque fluctuation of the engine to be transmitted to the drivetrain while enhancing the transmission efficiency of the torque converter. The feedback controller of the slip speed adopts the H∞ (H-Infinity) control theory which offers a high level of robust stability, and is the first of its kind in a mass produced component. As a result, a highly accurate and reliable system has been realized, contributing to large-scale fuel economy.
Technical Paper

High Durability of Metal Support for Automotive Catalyst

1995-02-01
950622
A metal support for use in an automotive catalyst is exposed to the severe heat cycle brought about by the intermittent flow of a high temperature exhaust gas. Accordingly, the metal support must have high beat resistance(ex. oxidation resistance) and a rigid structure. Therefore, 20% chromium-5% aluminum ferritic stainless steel(containing small quantities of rare earth metals and titanium) is used as a highly beat resistant honeycomb foil in addition to a highly mechanical durable brazing honeycomb structure. This study examined the durability of a metal honeycomb installed in a gasoline engine. Both an engine bench durability test of a manifold converter type metal support which is connected directly to the exhaust manifold of the gasoline engine and a vehicle durability test of an under the floor type metal support were carried out to evaluate oxidation damage of the metal honeycomb as well as its mechanical durability.
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.
Technical Paper

Effects of Lubricant Composition on Fuel Efficiency in Modern Engines

1995-02-01
951037
A bench engine test for evaluating the fuel efficiency of automotive crankcase oils using modern engines was developed. The fuel consumption was primarily proportional to the viscosity of the oils down to 5 mm2/s at operating temperatures, indicating that the use of low-viscosity oil was effective in improving fuel efficiency. This may be because the oil film would be formed easily, since sliding parts, such as valve train systems, in modern engines are finely finished. Organo molybdenum dithiocarbamates were effective in improving fuel efficiency at high temperature. A 2.7% improvement in fuel efficiency relative to conventional SAE 10W-30 oils was achieved by the combination of low-viscosity SAE 5W-20 oils and organo molybdenum dithiocarbamates under constant operating conditions with engine speed 1,500 rpm and torque 37.2 N•m.
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

Study of High Efficiency Zero-Emission Argon Circulated Hydrogen Engine

2010-04-12
2010-01-0581
The potential of high efficiency zero-emission engines fueled by hydrogen, which is regarded as a promising form of energy for the future, is being researched. The argon circulated hydrogen engine [ 1 ] is one system theoretically capable of achieving both high efficiency and zero emissions, and its feasibility for use in vehicles has been studied. Specifically, tests were performed to verify the following issues. It was examined whether stable hydrogen combustion could be achieved under an atmosphere of argon and oxygen, which has a high specific heat ratio, and whether the substantial thermal efficiency improvement effect of the argon working gas could be achieved. An argon circulation system was also studied whereby steam, which is the combustion product of the hydrogen and oxygen emitted from the engine, is separated by condensation to enable the remaining argon to be re-used.
Technical Paper

Research on Improving Thermal Efficiency through Variable Super-High Expansion Ratio Cycle

2010-04-12
2010-01-0174
The compression ratio and expansion ratio are fundamental parameters that determine the thermal efficiency of an SI engine, and the potential of setting these ratios to arbitrary values was studied as a way of improving engine efficiency. First, the efficiency resulting from different compression and expansion ratios was calculated from a theoretical formula. As a result, it was verified that a 20% improvement in thermal efficiency could be expected by adopting a super-high expansion ratio of 20 or higher, which is an extremely large value for an SI engine, while keeping the compression ratio within a range that can ensure appropriate combustion. Subsequently, this research calculated the possibility of improving engine efficiency under a condition that constrains the swept volume to a constant value in consideration of practicability.
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.
Technical Paper

Toyota's New Generation “Super ECT”(U140E) Four-Speed Automatic Transaxle

1999-03-01
1999-01-0749
Toyota Motor Corporation has developed a new four-speed automatic transaxle U140E named “Super ECT”. The U140E has achieved compactness which enables it to mount on many new platforms, achieved high efficiency, which contributes to improve fuel economy, and it achieved good shift feeling, response, and reduce noise. This paper shows the major features and performance of the U140E.
Technical Paper

Development of Innovative Dynamic Torque Vectoring AWD System

2019-04-02
2019-01-0332
This paper describes the development of an innovative AWD system called Dynamic Torque Vectoring AWD for all-wheel drive (AWD) vehicles based on a front-wheel drive configuration. The Dynamic Torque Vectoring AWD system helps to achieve high levels of both dynamic performance and fuel efficiency. Significant fuel economy savings are achieved by using a new compact disconnection mechanism at the transfer and rear units, which prevents any unnecessary rotation of the propeller shaft. In addition, the system is also capable of independently distributing torque to the rear wheels by utilizing electronically controlled couplings on the left and right sides of the rear differential. This greatly enhances both on-road cornering performance and off-road driving performance.
Technical Paper

Development of High Accuracy Rear A/F Sensor

2017-03-28
2017-01-0949
New 2A/F systems different from usual A/F-O2 systems are being developed to cope with strict regulation of exhaust gas. In the 2A/F systems, 2A/F sensors are equipped in front and rear of a three-way catalyst. The A/F-O2 systems are ideas which use a rear O2 to detect exhaust gas leaked from three-way catalyst early and feed back. On the other hand, the 2A/F systems are ideas which use a rear A/F sensor to detect nearly stoichiometric gas discharged from the three-way catalyst accurately, and to prevent leakage of exhaust gas from the three-way catalyst. Therefore, accurate detection of nearly stoichiometric gas by the rear A/F sensor is the most importrant for the 2A/F systems. In general, the A/F sensors can be classified into two types, so called, one-cell type and two-cell type. Because the one-cell type A/F sensors don’t have hysteresis, they have potential for higher accuracy.
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