Refine Your Search



Search Results

Journal Article

Prediction of Wear Loss of Exhaust Valve Seat of Gasoline Engine Based on Rig Test Result

The purpose of this research was to predict the amount of wear on exhaust valve seats in durability testing of gasoline engines. Through the rig wear test, a prediction formula was constructed with multiple factors as variables. In the rig test, the wear rate was measured in some cases where a number of factors of valve seat wear were within a certain range. Through these tests, sensitivity for each factor was determined from the measured wear data, and then a prediction formula for calculating the amount of wear was constructed with high sensitivity factors. Combining the wear amount calculation formula with the operation mode of the actual engine, the wear amount in that mode can be calculated. The calculated wear amount showed a high correlation with the wear amount measured in bench tests and the wear amount measured in vehicle tests.
Journal Article

Development of Base Metal Catalyst and Its Compatibility Study for Motorcycle Applications

We developed a copper catalyst using zero Platinum group metals (hereafter PGMs) to fit motorcycle specific emission gas environment. Though many research reports to develop catalyst without using PGMs that are precious and costly resources are available, no reports had proven Base Metal Catalyst development to meet actual emission regulation equivalent to PGM catalysts. Compared to conventional PGM catalysts, higher temperature is required to keep high catalytic conversion efficiency by utilizing properties of this Base Metal Catalyst. Thus, this Base Metal Catalyst is located in cross coupling position, though it is rare case in motorcycle. This catalyst location could cause negative impacts on engine knocking, engine performance and drivability. This time, to overcome such negative impacts we optimized whole exhaust system, including parts around catalyst.
Technical Paper

On Demand Octane Number Enhancement Technology by Aerobic Oxidation

For the purpose of developing onboard gasoline reforming technology for higher octane number fuel on demand, octane number enhancement of gasoline surrogate by aerobic oxidation using N-hydroxyphthalimide catalyst was investigated. At first, octane numbers of the oxygen-containing products from alkane and aromatic compound were estimated using a fuel ignition analyzer. As a result, not only alcohol but also ketones and aldehydes have higher octane numbers than the original alkanes and aromatic compound. Next, gasoline surrogate was oxidized aerobically with N-hydroxyphthalimide derivative catalyst and cobalt catalyst at conditions below 100 °C. As a result, fuel molecules were oxidized to produce alcohols, ketones, aldehydes, and carboxylic acids. N-hydroxyphthalimide derivative catalyst with higher solubility in gasoline surrogate has higher oxidation ability. Furthermore, the estimated octane number of the oxidized gasoline surrogate improves 17 RON.
Technical Paper

Development of a New 1.5L I4 Turbocharged Gasoline Direct Injection Engine

A 1.5 L downsizing turbocharged engine was developed to achieve both driving and environmental performance. The engine is intended to replace 1.8 - 2.4 L class NA engines. In downsizing turbocharged engines, mixture homogeneity is important for suppressing knocking and emission reduction. Particularly under high load, creating rapid combustion and a homogeneous mixture are key technologies. The authors used a long-stroke direct injection engine, which has outstanding rapid combustion and thermal efficiency, as a base engine meeting these requirements. They combined this with a high-tumble port and shallow-dish piston intended to support tumble flow. The combination enhanced flow within the cylinder. The combustion system was built to include a sodium-filled exhaust valve to reduce knocking and a multi-hole injector (six holes) for mixture homogeneity and to reduce the fuel wall wetting.
Technical Paper

Development of New 3.5 L V6 Turbocharged Gasoline Direct Injection Engine

This paper introduces the newly developed super sports car engine mounted in the new model NSX. A super sports car engine was newly developed to satisfy the high power performance required by the body package. Higher power and compactness were simultaneously achieved by selecting an engine displacement of 3.5 L and by using a V6 layout and a turbocharger. This enabled to mount a power train that combines a hybrid motor with a newly developed transmission in the rear of the body. The lubrication system uses a dry sump system capable of maintaining reliable lubrication in all possible super sports car driving scenarios. The combustion system uses high tumble-flow ports, a direct injection and a port injection system that increase power performance and thermal efficiency, emission reduction. To support the increased heat load due to higher power, a 3-piece water jacket is used around the combustion chamber and the exhaust ports.
Technical Paper

Study of Ethanol-Gasoline Onboard Separation System for Knocking Suppression

Bio-ethanol is used worldwide in fuel mixtures such as E10 gasoline. In this study, an onboard fuel system employing a pervaporation membrane was investigated to separate E10 into high-octane-number fuel (high-concentration ethanol fuel) and low-octane-number fuel (low-concentration ethanol fuel). The optimal operation conditions and size of the membrane unit for the separation system were determined in consideration of the separation rate and vehicle installation. This system can supply separated ethanol with sufficient speed and quantity to improve engine performance under practical driving conditions. In addition, the study was conducted to confirm that separated fuels have properties sufficient for use in automobiles. This separation rate enabled 5-cycle-mode driving without temporary shortage of permeated fuel.
Technical Paper

Analysis for Influence of Inhomogeneity of Air-Fuel Mixture to Super-Knock Caused by Pre-ignition in Supercharged Direct-Injected SI Engine Based on Numerical Calculation

Nowadays, highly super charging is required corresponded to downsizing concept for improving thermal efficiency in direct-injected spark ignition (DISI) engine. However, highly super charging increases the possibility of super-knock caused by pre-ignition. Recently, in many studies, the reason of pre-ignition has been investigated but the reason why pre-ignition leads such strong knocking called super-knock has not been investigated. In DISI engine, it is estimated that there is more inhomogeneity of equivalence ratio and temperature of air-fuel mixture than it in port injection SI engine. In this study, factors which decide self-ignition timing was reviewed and the influence of inhomogeneity of air-fuel mixture to super-knock was investigated based on numerical calculation.
Technical Paper

Validation of Turbulent Combustion and Knocking Simulation in Spark-Ignition Engines Using Reduced Chemical Kinetics

Downsizing or higher compression ratio of SI engines is an appropriate way to achieve considerable improvements of part load fuel efficiency. As the compression ratio directly impacts the engine cycle thermal efficiency, it is important to increase the compression ratio in order to reduce the specific fuel consumption. However, when operating a highly boosted / downsized SI engine at full load, the actual combustion process deviates strongly from the ideal Otto cycle due to the increased effective loads requiring ignition timing delay to suppress abnormal combustion phenomena such as engine knocking. This means that for an optimal design of an SI engine between balances must be found between part load and full load operation. If the knocking characteristic can be accurately predicted beforehand when designing the combustion chamber, a reduction of design time and /or an increase in development efficiency would be possible.
Technical Paper

Study of Knocking Damage Indexing Based on Optical Measurement

Attempts were made to measure knocking phenomenon by an optical method, which is free from influences of mechanical noises and is allowing an easy installation to an engine. Using a newly developed high durability optical probe, the light intensity of hydroxyl radical component, which is diffracted from the emitted light from combustion, was measured. The intensity of this emission component was measured at each crank angle and the maximum intensity in a cycle was identified. After that, the angular range in which the measured intensity exceeded 85% of this maximum intensity was defined as “CA85”. When a knocking was purposely induced by changing the conditions of the engine operation, there appeared the engine cycles that included CA85 less than a crank angle of 4 degrees. The frequency of occurrence of CA85 equal to or less than 4 degrees within a predetermined number of engine cycles, which can be interpreted as a knocking occurrence ratio, was denoted as “CA85-4”.
Technical Paper

Development of Pd-Only Catalyst for LEV III and SULEV30

This research is aimed at development of the catalyst for gasoline automobiles which uses only palladium (Pd) among platinum group metals (PGMs). And the conformity emission category aimed at LEV III-SULEV30. For evaluation, the improvement effect was verified for 2013 model year (MY) ACCORD (LEV II-SULEV) as the reference. As compared with Pd-rhodium (Rh) catalyst, a Pd-only catalyst had the low purification performance of nitrogen oxides (NOx), and there was a problem in the drop in dispersion of Pd by sintering, and phosphorus (P) poisoning.
Journal Article

Study of High-Compression-Ratio Engine Combined with an Ethanol-Gasoline Fuel Separation System

Bio-ethanol is used in many areas of the world as ethanol blended gasoline at low concentrations such as “E10 gasoline”. In this study, a method was examined to effectively use this small amount of ethanol within ethanol blended gasoline to improve thermal efficiency and high-load performance in a high-compression-ratio engine. Ethanol blended gasoline was separated into high-concentration ethanol fuel and gasoline using a fuel separation system employing a membrane. High-ethanol-concentration fuel was selectively used at high-load conditions to suppress knocking. In this system, a method to decrease ethanol consumption is necessary to cover the wide range of engine operation. Lower ethanol consumption could be achieved by Miller-cycle operation because decrease of the effective compression ratio suppresses knocking. However, high-load operation was limited due to the decrease in intake air volume with Miller-cycle operation.
Journal Article

Development of a New Two-Motor Plug-In Hybrid System

A highly efficient two-motor plug-in hybrid system is developed to satisfy the global demands of CO2 reduction. This system switches three operation modes, what is called “EV Drive”, “Hybrid Drive” and “Engine Drive”, to maximize fuel efficiency according to the driving condition of the vehicle. Practical plug-in EV (Electric Vehicle) capability is also realized by adding a high-power on-board charger and a high capacity Li-ion battery to the original system. The outlines of the system components including a newly developed Atkinson cycle engine, a highly efficient electric coupled CVT (Continuously Variable Transmission) with built-in motor and generator, an integrated PCU (Power Control Unit) and an exclusive battery for plug-in HEV (Hybrid Electric Vehicle) are described in this paper. In addition to the switching of three driving modes and the efficiency improvement of each device, cooperative control of the hybrid system is introduced.
Technical Paper

Development of Gasoline Combustion Reaction Model

Gasoline includes various kinds of chemical species. Thus, the reaction model of gasoline components that includes the low-temperature oxidation and ignition reaction is necessary to investigate the method to control the combustion process of the gasoline engine. In this study, a gasoline combustion reaction model including n-paraffin, iso-paraffin, olefin, naphthene, alcohol, ether, and aromatic compound was developed. KUCRS (Knowledge-basing Utilities for Complex Reaction Systems) [1] was modified to produce paraffin, olefin, naphthene, alcohol automatically. Also, the toluene reactions of gasoline surrogate model developed by Sakai et al. [2] including toluene, PRF (Primary Reference Fuel), ethanol, and ETBE (Ethyl-tert-butyl-ether) were modified. The universal rule of the reaction mechanisms and rate constants were clarified by using quantum chemical calculation.
Journal Article

Research on Clogging Mechanism of Multilayered Fuel Filters and Extension of Filter Life Span in Ethanol Blended Fuel

Recently, the use of ethanol blended fuel is growing worldwide. Therefore, there is increasing needs for addressing issues relating to ethanol blended fuel use in gasoline engine fuel supply systems. In this paper, we focused on one of such issues, which is the reduced life of a multi-layered fuel filter used at inlet side of a fuel pump when it is used with ethanol blended fuel. In this study, we clarified that ethanol blended fuel tends to disperse dust particles contained in fuel to a greater extent than gasoline, and that it has a mechanism to accelerate clogging by concentrating the clogging only on the finest layer of the multi-layered filter. Also, in the process of clarifying this principle, we confirmed that dust particles dispersed by ethanol are coagulated when passing through the filter layers.
Technical Paper

Investigations of the impact of 10% ethanol blended fuels on performances of sold gasoline vehicles in the Japanese market already on the road in Japan

The study of 10% ethanol blended gasoline (E10 gasoline) utilization has been conducted in the Japan Auto-Oil Program (JATOP). In order to clarify the impact of E10 gasoline on vehicle performances, exhaust emissions, evaporative emissions, driveability and material compatibility have been investigated by using domestic gasoline vehicles including mini motor vehicles which are particular to Japan. The test results reveal that E10 gasoline has no impact on exhaust emissions, engine startup time and acceleration period under the hot start condition, but a slight deterioration is observed in some test cases under the cold start condition using E10 gasolines with 50% distillation temperature (T50) level set to the upper limit of Japanese Industrial Standards (JIS) K 2202. Regarding evaporative emissions, the tested vehicles shows no remarkable increase in the hot soak loss (HSL), diurnal breathing loss (DBL) and running loss (RL) testing with E10 gasolines.
Technical Paper

Research into Optimal Specifications for Flexible Fuel Vehicle Engines

Various plant-derived alternative fuels have been proposed in recent years as ways to curb the global warming that occurs from the CO2 that is emitted by internal combustion engines. One such fuel is bioethanol. In Brazil, flexible fuel vehicles (FFV) are used that can run on blends from 100% hydrous ethanol (E100) to gasoline containing 22% ethanol (E22). This research addresses the optimal specifications of a FFV engine. FFV engines use E100 and E22 in any ratio. E100 has a very high RON of approximately 110, while that of E22 is low at approximately 95. The researchers considered these characteristics when selecting a compression ratio capable of providing good performance at any ethanol blend ratio. Additionally, ethanol is a single-component fuel without low-boiling-point components, so it has poor combustion at low temperatures. In general, FFV engines are often built with one intake valve to enhance product usability at low temperatures.
Technical Paper

Flexible-Fuel System for Small Motorcycles

A flexible-fuel system for small motorcycles has been developed that can utilize both gasoline, and ethanol as an alternative to fossil fuel. For practicality, we aimed to develop a system that uses a minimum of additional parts. As a method to make both ethanol and gasoline available with the system, a control algorithm that estimates the ethanol concentration by utilizing the output voltage of an OXYGEN SENSOR and selects the appropriate injection quantity is employed. Usually, in automotive flexible-fuel vehicles (FFV), sub-tanks are mounted to ensure engine startability in cold temperatures. However, in small motorcycles, limitations of mounting space must be addressed. In this system, by clarifying the control logic and determining the difficult cases for cold temperature starts due to high ethanol concentration, configuring the indicator to promote gasoline mixture when the start is difficult enabled the elimination of the sub-tanks.
Journal Article

Exhaust Valve & Valve Seat Insert – Development for an Industrial LPG Application

Automotive engines are regularly utilized in the material handling market where LPG is often the primary fuel used. When compared to gasoline, the use of gaseous fuels (LPG and CNG) as well as alcohol based fuels, often result in significant increases in valve seat insert (VSI) and valve face wear. This phenomenon is widely recognized and the engine manufacturer is tasked to identify and incorporate appropriate valvetrain material and design features that can meet the ever increasing life expectations of the end-user. Alternate materials are often developed based on laboratory testing – testing that may not represent real world usage. The ultimate goal of the product engineer is to utilize accelerated lab test procedures that can be correlated to field life and field failure mechanisms, and then select appropriate materials/design features that meet the targeted life requirements.
Technical Paper

Next Generation Formed-In-Place Gasket (FIPG) Liquid Sealant for Automotive Intake Manifold Application

Intake manifold is a part of an engine that supplies fuel/air mixture to the cylinder heads. Recently, silicone FIPG has been used for the two part design of the intake manifold. It is known that a small, but significant, amount of gasoline fuel can penetrate through silicone FIPG layer due to the flexible nature of the siloxane backbone. Since gasoline permeation is becoming more important because of more severe regulations, it is found that a new polyacrylate based FIPG dramatically reduces the gasoline fuel permeation. This study compares this new technology, polyacrylate FIPG sealant with silicone FIPG sealant used today for vehicle powertrain gasketing applications. Adhesion investigation on both aluminum and magnesium alloys, and oil resistance are also discussed in this study.
Journal Article

Hot Surface Ignition of Gasoline-Ethanol Fuel Mixtures

The purpose of this paper is to present the results of hot surface ignition (HSI) testing and American Society for Testing and Materials (ASTM) auto-ignition testing (AIT) performed on gasoline fuel mixtures containing varying levels of ethanol. With the increased consumer interest in ethanol-based fuels as a measure of reducing the United States dependence on foreign oil, the use of E85 and other ethanol/petroleum fuel blends is on the increase. While some autoignition data for summer and winter blends of gasoline on hot surfaces exist beyond the standard ASTM E659-78 test procedure [1], there is little data on ethanol-based fuels and their HSI characteristics.