Search Results

Idle speed reduction is one of the important solutions for fuel economy improvement. However, idle speed reduction requires improving the disturbance rejection performance of idle speed control to prevent malfunctions such as engine stall. In mass production engines, PID control is mainly used for the idle speed control because of easiness of the design. However the idle speed control system has nonlinear characteristics. Therefore we have developed the algorithm based on the sliding mode control(SMC) [1]. As a result, superior performance was obtained [2]. Furthermore, for performance, we developed the new algorithm based on Tuning Functions (TF) [3]. As a result, high disturbance rejection performance was obtained.

Two working groups in the JSAE Committee of Fatigue–Reliability Section1 are currently researching the issue of fatigue life by both experimental and the CAE approach. Information regarding frequent critical problems on arc–welded structures were sought from auto–manufacturers, vehicle component suppliers, and material suppliers. The method for anti–fatigue design on arc–welded structures was established not only by a database created by physical test results in accordance with the collected information but also with design procedure taking Fracture–Mechanics into consideration. This method will be applied to vehicle development as one of the virtual laboratories in the digital prototype phase. In this paper, both the database from bench–test results on arc welded structures and FEA algorithm unique to JSAE are proposed some of the analysis results associated with the latter proposal are also reported.

When CNG, LPG, and other gas fuels were used for combustion in vehicles' engines, a large degree of valve seat wear was observed and it was difficult to provide the same wear resistance as for gasoline engines. Therefore, the mechanism of valve seat wear in gas fuel engines was analyzed and an alloy valve seat was developed. In addition to converting the matrix to an alloy, Co-Mo-Cr was used for the self-lubricating effect present in its hard particles. Also, in order to improve machinability, which is inversely related to wear resistance, a sintered alloy valve seat containing MnS was developed. As a result, wear resistance equal to that for gasoline engines was achieved.

Detergent additives in automotive gasoline fuel are mainly designed to reduce deposit formation on intake valves and fuel injectors, but it has been reported that some additives may contribute to CCD formation. Therefore, a standardized bench engine test method for CCDs needs to be developed in response to industry demands. Cooperative research between the Petroleum Association of Japan (PAJ) and the Japan Automobile Manufacturers Association, Inc. (JAMA), has led to the development of a 2.2L Honda engine dynamometer-based CCD test procedure to evaluate CCDs from fuel additives. Ten automobile manufacturers, nine petroleum companies and the Petroleum Energy Center joined the project, which underwent PAJ-JAMA round robin testing. This paper describes the CCD test development activities, which include the selection of an engine and the determination of the optimum test conditions and other test criteria.

Most currently produced lean-burn engines can achieve good fuel economy, but must be further developed to gain better vehicle performance and driveability. Honda has developed a new lean-burn engine which incorporates 3-stage variable valve timing and lift mechanism, swirl promotion at low engine speed, and a new intake port configuration. This engine generates approximately 40% more power over our current lean burn engine and improves the dynamic performance of the vehicle. At the same time, it maintains a fuel consumption level equal to that of the current engine.

The orientation of electrodeposited Pb alloy crystal was related to the morphology of the deposits, and the orientated electrodeposits of a Pb alloy mainly consisting of the (h00) plane have exhibited a good wetness characteristic for lubricant oil. As a result, the orientated electrodeposits of this Pb alloy used in the overlay of bearings has an anti-seizure parameter (PV) at least 30% higher than that of conventional deposits in terms of the sliding characteristic. The sintered lead-bronze alloy used as the bearing's lining material offers good fatigue strength, which was made possible by adopting a newly developed Cu-Sn alloy matrix and reducing the amount and grain size of the Pb phase. Studies on plane bearings of high performance have clarified through bearing characteristic and engine firing tests that combining the orientated Pb alloy overlay and strengthening the lining increases the anti-seizure property and improves durability with regard to bearing fatigue and wear.

This paper summarizes some of the technical considerations upon which Honda's CVCC system is based, relating to reduction of pollutants in automobile engine exhaust gases. The CVCC engine employs a stratified charge to produce stable combustion of an overall lean mixture. A unique mixture is formed immediately before ignition to reduce three pollutants (CO, HC, and NOx) simultaneously, as well as to improve fuel economy. This mixture is produced by contolling fuel mixtures supplied to the engine and by geometrical combustion chamber design features. An evaluation model conceived by Honda to evaluate emissions and fuel economy during the driving cycle mode is explained, and a comparison of estimated values obtained from the evaluation model with those obtained under actual driving test conditions is made.