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Bioethanol is being used as an alternative fuel throughout the world based on considerations of reduction of CO2 emissions and sustainability. It is widely known that ethanol has an advantage of high anti-knock quality. In order to use the ethanol in ethanol-blended gasoline to control knocking, the research discussed in this paper sought to develop a fuel separation system that would separate ethanol-blended gasoline into a high-octane-number fuel (high-ethanol-concentration fuel) and a low-octane-number fuel (low-ethanol-concentration fuel) in the vehicle. The research developed a small fuel separation system, and employed a layout in which the system was fitted in the fuel tank based on considerations of reducing the effect on cabin space and maintaining safety in the event of a collision. The total volume of the components fitted in the fuel tank is 6.6 liters.

In recent years, electrification of powertrains has been promoted to improve fuel efficiency and CO2 emissions. Along with electrification, it is possible to reduce engine usage frequency and improve the fuel efficiency in traveling. Especially in a hybrid electric vehicle (HEV), the state changes from motor assist mode to engine firing mode. As a result, stay time in eigenvalue of a powertrain is shortened, and vibration of the vehicle body at the engine start situation is able to be reduced as compared with conventional engine-driven vehicle. However, since the HEV is equipped with a high compression ratio engine for improving fuel economy, there is cause for concern that excitation force generated by the powertrain at the time of engine start increases. Also, the vehicle body vibration at engine start situations requires further consideration, because the operation frequency of engine decreases.

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.

Idling stop systems are being increasingly adopted in conventional engine vehicles as well as hybrid electric vehicles to increase fuel efficiency. When the engine starts, body vibration occurs that is caused by the rigid body eigenvalues of the power plant during initial combustion. Engine restart vibration after an idling stop is caused by the input force from the transmission, and the reaction force from the drive shaft as well as the input force from the engine. This phenomenon occurs frequently when the engine is restarted from the idling stop, the vibration is increasingly annoying to passengers. Usually, the vehicle development process is carried out in accordance with the V process. The V process divides the vehicle development process into two stages. The first stage is called the vehicle design stage to determine the characteristic. The second stage is called the vehicle verification stage to verify the performance.

In recent years, improvements in the fuel economy and exhaust emission performance of internal combustion engines have been increasingly required by regulatory agencies. One of the salient concerns regarding general purpose engines is the larger amount of CO emissions with which they are associated, compared with CO emissions from automobile engines. To reduce CO and other exhaust emissions while maintaining high fuel efficiency, the optimization of total engine system, including various design parameters, is essential. In the engine system optimization process, cycle simulation using 0-D and 1-D engine models are highly useful. To define an optimum design, the model used for the cycle simulation must be capable of predicting the effects of various parameters on the engine performance. In this study, a model for predicting the performance of a general purpose SI (Spark Ignited) engine is developed based on the commercially available engine simulation software, GT-POWER.

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.

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.

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.

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.

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.

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.

The vehicle air-conditioning system has significant impact on fuel economy and range of electric vehicles. Improving the fuel economy of vehicles therefore demand for energy efficient climate control systems. Also the emissions regulations motivate the reduced use of fuel for vehicle's cabin climate control. Solar heat gain of the passenger compartment by greenhouse effect is generally treated as the peak thermal load of the climate control system. Although the use of advanced glazing is considered first to reduce solar heat gain other means such as ventilation of parked car and recirculation of cabin air also have impetus for reducing the climate control loads.

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.

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”.

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.

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.

In the automobile industries, weight reduction has been investigated to improve fuel efficiency together with reduction of CO2 emission. In such circumstance, it becomes necessity to make an electric power steering (EPS) more compact and lightweight. In this study, we aimed to have a smaller and lighter EPS gear size by focusing on an impact load caused at steering end. In order to increase the shock absorption energy without increase of stopper bush size, we propose new theory of impact energy absorption by not only spring function but also friction, and a new stopper bush was designed on the basis of the theory. The profile of the new stopper bush is cylinder form with wedge-shaped grooves, and when the new stopper bush is compressed by the end of rack and the gear housing at steering end, it enables to expand the external diameter and produce friction. In this study, we considered the durability in the proposed profile.

As the motorcycle market grows, the fuel efficiency of motorcycle oils is becoming an important issue due to concerns over the conservation of natural resources and the protection of the environment. Fuel efficient engine oils have been developed for passenger cars by moving to lower viscosity grades and formulating the additive package to reduce friction. Motorcycle oils, however, which operate in much higher temperature regimes, must also lubricate the transmission and the clutch, and provide gear protection. This makes their requirements fundamentally very different from passenger car oils. Developing fuel efficient motorcycle oils, therefore, can be a difficult challenge. Formulating to reduce friction may cause clutch slippage and reducing the viscosity grade in motorcycles must be done carefully due to the need for gear protection.

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.

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.