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Auto-regeneration of diesel particulate traps, particularly combustion mode of soot in a wall flow filter with fuel additives, was investigated using a diesel engine of a light duty truck and truck itself. Soot burning in the trap and regeneration were observed under any engine operating condition including prolonged idling and stop-and-go driving at 0.18g metal/1 dosage of a mixture of copper and lead in the fuels. However, trap life was limited by ash clogging due to the metallic compounds. Although the influence of metallic additives on the environment was debatable, test results of the trap durability and calculations of soot burning based on the thermal ignition theory indicated that dosage and kind of fuel additives should be optimized in view of both trap life and reliability of soot burning.

A Vehicle Vibration Control System by Active Control has been developed. The experimental results using a 4-cylinder gasoline engine installed in a car showed that at the position of the driver's seat, the acceleration of the vibration was reduced by 16 dB. This system operates stably and at low cost because of having a feedforward system, so many applications can be expected in the near future as methods for vehicle vibration reduction.

The accuracy of real-time A/F measurement at engine test benches has been improved with a modified equation to calculate A/F from exhaust gas composition. In addition to CO, CO2, total hydrocarbon (THC) and O2, the proposed equation includes NO and NO2 concentration as variables. In an attempt to improve the accuracy of the assumed constants in the equation, experiments have been conducted using automotive exhaust H2O and H2 analyzers. The accuracy of the proposed equation was proven through experiments and it was also found useful for precise evaluation of three-way catalyst or oxygen sensor characteristics.

There have been various predictions made concerning the future profile for automobiles but such predictions have in many cases been based solely on anticipated advances in technology. In presenting a profile for automobiles in the year 2000, the writers predict the evolution and transfiguration of automobiles, taking both phases in the changing social environment and technical trends into account. Interest in automobiles is expected to shift from hardware to software and then to humanware (i.e. more emphasis is placed on the relationship with human beings), and automobiles will evolve and transfigure reflecting these changes.

In order to investigate the effects of high injection pressure on engine performance and exhaust emissions, some experimental high injection pressure in-line pumps were made and tested. Increasing fuel spray momentum by high injection pressure could reduce smoke emission, but excessive increase in injection pressure was found not so effective in further reducing smoke emission. Accordingly, a high injection pressure should be accomplished within the low engine speed range a feature that has been very difficult to achieve for a conventional in-line pump. An electronic controlled injection-rate-control pump with a variable prestroke mechanism can provide higher injection pressure in low engine speed range and advances injection timing in high engine speed range. This pump can improve fuel economy in low engine speed range and emissions (smoke and particulate) over transient FTP for HDE's.

Periodic oscillations of the speed of SI engine with MPI system at idle observed in the steady state and in the converging process after the inditial increase of load were investigated. These non-steady phenomena are the self-excitations of the closed-loop system induced by the lag factors inherent to the system such as the manifold charging delay and the fuel metering and transport lag and by the nonlinear factors such as the sensitivity of the torque to the equivalence ratio. But, even in the cases where the lags and the nonlinearity are insufficient, continuous oscillations with large amplitude are observed in the actual engine. They can be explained by introducing the concept of external perturbation induced by the combustion fluctuation. Disturbance prevents the phase lag in the system from converging, resulting in the continuation of oscillation.

Various parameters for the shift scheduling of an automatic transmission were examined to detect more accurate road conditions, vehicle running conditions, and the driver's intention. The parameters include the vehicle speed, the gradient of a road, an index to curves in the road, and so on. The fuzzy logic was employed to incorporate these parameters into the shift scheduling control. The vehicle running tests have shown that the use of many parameters and the fuzzy logic was effective on reducing the frequencies of the transmission gear shift and the driver's brake operation in such road conditions as usually seen in mountainous areas

In the next few years, the USA, EU, and Japan plan to introduce very stringent exhaust emissions regulations for heavy–duty diesel engines, in order to enhance the protection air quality. This builds upon the heavy–duty diesel engine exhaust emissions regulations already in effect. At the same time, improvement in fuel consumption of heavy–duty diesel engines will be very important for lowering vehicle operating costs, conserving fossil fuel resources, and reduction of CO2 (greenhouse gas) levels. This paper presents a detailed review of a quiescent combustion system for a heavy–duty diesel engine, which offers breakthrough performance in terms of the exhaust emissions – fuel consumption trade–off, compared with the more conventional swirl supported combustion system. This conclusion is supported by experimental results comparing quiescent and swirl supported versions of various combustion system configurations.

In this study, the oxidation stability, soot dispersancy, antiwear performance, and friction-reducing capability of friction modifiers (FMs) were evaluated, and an SAE 5W-30 fully synthetic oil with MoDTC type FMs was developed for heavy-duty diesel engines. In several engine tests, it was confirmed that the developed oil can double the oil drain interval in comparison with API CD SAE 30, even when EGR is applied, and improves the fuel efficiency.

Global environment protection, Co2 emission reduction and so on, is an important problem in automotive industry. An Electric Vehicle (EV) production is one of policies. Co2 emission of EV is lower than Internal Combustion Engine (ICE), petrol and diesel engine. On the other hand, customer's needs for the comfort on driving increase year after year. So it's an important factor for new car performance. Generally speaking, it's thought that the noise and vibration performance of EV have the better of ICE performance. However the aerodynamic noise and road noise contribution for interior noise in EV rise in comparison with ICE, and moreover the sound quality change by new noise component of the motor noise. Therefore new sound evaluation method is needed for EV. So this paper demonstrates each noise component contribution in EV by new noise separation technology, and show the comparison result with EV and ICE.

Mitsubishi Motors Corporation succeeded in mass production of the electric vehicle “i-MiEV” which features leading-edge technologies epitomized by lithium-ion battery. The EV was released into the Japanese market in July 2009 and the European market in January 2011. In order to be used all over the world, the EV has to be practical and durable even under severe weather of extremely cold or extremely hot regions. In this paper we report some results of the tests conducted under extremely cold weather as well as extremely hot weather. From the test results the validity of the vehicle control system and the practicality of the EV are verified.

An efficient cooling system will ensure the reliability of the EV/HEV (Electric Vehicle/Hybrid Electric Vehicle) battery system and extend their lifetime. In order to shorten design period or increase design iterations, a high-speed and high-precision prediction method for cooling is indispensable. For models, such as Mitsubishi i-MiEV, which use fresh air to cool batteries in the battery pack, a transient approach based on loosely coupled method is developed to predict temperature change of batteries. The results by our new approach are in good agreement with the experimental data. Moreover, for the EV/HEV using circulated air to cool its batteries, a second approach is also developed, which can predict the temperature variations of both EV/HEV batteries in the battery pack and the cooling air.

The purpose of this paper is to present a prediction method for the refrigerator performance of an automotive air conditioner (A/C). In order to predict the refrigerator performance in arbitrary situations, we consider the thermal equilibrium of the refrigeration cycle through A/C components, as the compressor, the evaporator and the condenser. These components are affected by the thermal property of the refrigerant. Influences of circumstantial flow and temperature field in the engine compartment also are reflected upon, because the cooling performance of the condenser is sensitive to that. In this paper, we try to derive algebraic models for the major components with regard to the thermal equilibrium in the refrigeration cycle. Furthermore, we use a Computational Fluid Dynamics analysis (CFD) for the prediction of cooling airflow temperature in the engine compartment, which is another essential factor in determining the state of the refrigeration cycle.

This paper describes the results of the study and research on ovate wire helical springs which have been jointly conducted by the members of the Japan Society for Spring Research consisting of the engineers from material suppliers, wire and spring producers and automotive manufacturers as well as researchers at Japanese universities. Attention is focused particularly on two types of wire cross sections, typical elliptical shape and Fuchs' egg-shape. Stresses on these two cross sections were analyzed by numerical calculations within the range of practical specification, and then the results have been compared with those of round wire spring. As a result, it has been found that the elliptical wire spring is superior to Fuchs- egg-shaped one for general application. Simple designing methods for the both types of wire helical springs have been developed based on the findings from the stress analysis.