The influence on valve temperature of back pressure engine valve temperature and operating parameters -3-

Abstracts /JSAE Review 18 (1997) 185-209 method was examined using a test FF vehicle and the same smooth torque was obtained when the new method was employed. 9637159 Study on a Metal Pushing V.Belt Type CVT - - Numerical Analysis of Forces Acting on a Belt at Steady State Shinya Kuwahara, Yoshiki Fushimi (Doshisha University Graduate School), Toru Fujii (Doshisha University), Shigeru Kanehara (Honda R & D Co., Ltd.) A numerical model was developed to analyze the power transmitting mechanisms for a metal pushing V-belt type CVT at steady state. The model consists of linear springs representing the rigidities of blocks and rings, and interface elements which identify slippage between two contacting objects. By using the present model, forces acting on the belt were calculated. Calculated results were compared with the experimental results and reasonable agreement between both results was obtained. The numerical analysis reveals that the rings are sliding on the driven pulley and transmit negative power at the speed ratio i < 1.0. Consequently, the blocks transmit greater power for i < 1.0 than that for i > 1.0. 9637168 Fracture of Valve Head and Engine Operating Condition Engine Valve Temperature and Operating Parameters -2- Haruki Kobayashi, Luchuan Yang, Makoto Adegawa, Kizuku Ohtubo (Fuji OOZX Inc.) According to the result of thermal stress analysis, it is considered that one of the reasons for valve head fracture is the tensile stress caused by temperature distribution. According to the data measured in a Diesel engine valve, the temperature difference on the valve under transition conditions is greater than that under constant conditions. Therefore, a stronger stress is produced. The results show that the durability test should be carried out under transition conditions rather than only under the condition of constant high level load. 9637177 The Influence on Valve Temperature of Back Pressure Engine Valve Temperature and Operating Parameters -3- Haruki Kobayashi, Makoto Adegawa, Kizuku Ohtubo (Fuji OOZX Inc.) In the previous paper, the relation between excess air ratio and valve temperature was reported. In this paper, the relation between back pressure, which is the factor which affects the excess air ratio, and the valve temperature is discussed. The higher the back pressure, the higher the exhaust gas temperature, in other words, the higher the valve temperature. It can be deduced that the problem of the valve is closely related to the problems of the components in the exhaust system, such as exhaust brake shudder. 9637186 Development of Titanium Nitride Coated Shim for A Direct Acting OHC Engine Michihikn Masuda, Kenji Shimoda, Kouji Nishida, ikuo Marumoto, Ujino Masato (Toyota Motor Corp.) In order to meet requirements for lower fuel consumption, we have developed a technique for significantly decreasing valve train friction for a direct acting OHC engine. The droplets generated by titanium nitride coating the shims improve the surface roughness of the cams, eliminating the need to polish the cams. In an engine with these shims, the surface roughness of the cams are considerably improved within a few minutes of operation by the polishing action of the droplets. The valve train friction is greatly reduced by improving the surface roughness of the cams and shims resulting in better fuel economy. 9637195 Study of Combustion Chamber Deposit Formation Mechanism - Part 1: Characterization of Deposits Yasuo Esaki, Noritomo Suzuki, Koji Kimoto, Toshimi Araga (Toyota Central R & D Labs., Inc.), Kazuhikn Shiratani (Toyota Motor Corp.) Combustion chamber deposits were characterized by physical and chemical analyses, and their formation mechanism was discussed. The two types of deposits, derived from fuel and engine oil, could be distinguished from each other through the analyses of the deposits in an early stage of their formation. Fuel derived deposits were assumed from their chemical structures to be oxidation and polymerization products of

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aromatic fuel components in a quench area, and the validity of this assumption was verified by laboratory tests under high pressure conditions. 9637203 Study of Combustion Chamber Deposit Formation Mechanism - Part 2: Influence of Fuel and Gasoline Detergent Takashi Uehara, Yasunori Takei, Yoshitaka Nakatani, Kazuhiko Shiratani, Masanori Okada, Hiroo Sagami (Toyota Motor Corp.), Yasuo Esaki (Toyota Central R & D Labs., Inc.) In order to investigate the CCD (Combustion Chamber Deposit) formation mechanism, Engine dynamometer tests and laboratory tests were performed. In the dynamometer test, the influence of Fuels and Detergents on CCD amount was examined. In the laboratory test, the CCD formation tendency of Fuels and Detergents were examined. As a consequence, we have determined the mechanism of CCD formation and indicated the trend of fuel composition and detergent characteristics which form a small amount of CCD. 9637212 The Behaviour of Flame and Combustion Characteristics in a Swirl in an Engine Cylinder QiWu Xuan (Kyushu University Graduate School), Shinsuke Ono, Eiichi Murase, Hideaki Kawano, Mitsuo Nakaya (Kynshu University), Kotaro Oshima (Kynshu University Graduate School) The intermittent initiation of flame kernels in a swirling flow may give an effective means for the active control of combustion in the S.I. engine. In the present study, the multiple sparks from a single source are intermittently applied to the lean methane-air mixture with high swirl. The control of the interval between flamelets effectively changes the heat release rate in a combustion space. The adequate timing and interval of ignition results in a reduced Nox combustion while keeping a relatively higher Pmi, and the optimum separation of flamelets can be similarly controlled through the ignition interval of crank angle. 9637221 Emission Spectroscopic Measurement of OH Radical in a Two-cycle Engine Yasunori Amino, Shinjirou Higashizawa (Nihon University Graduate School), Koji Yoshida, Hideo Shoji, Atsushi Saima (Nihon University) The light emission behavior of OH radical was measured by emission spectroscope with the aim of gaining a better understanding of engine knocking. A two-cycle engine with a Schniirle scavenging system was used in this study. Simultaneous measurements were made of the emission intensity of OH radical in the end-gas region at four points of the combustion chamber. This showed a sharp rise on three measurement points on the intake port side, causing knocking pressure oscillations. Further, unburned end gas in large quantities autoignited at several places on the intake port side, producing strong knocking pressure oscillations. 9637230 Behavior of Pre-autoignition Reaction at Knocking Condition in Spark Ignition Engine Terunao Kawal (The University of Shiga Prefecture), Takaynki Hirose (Doshisha University Graduate School), Shuzou Miyake (Tokyo R & D), Jiro Senda, Hajime Fujimoto (Doshisha University) The knocking phenomenon in a spark ignition engine is led by autoignition in the unbumt gas region. This paper deals with the visualization and analysis of pre-autoignition reactions which occur in rapid compression and expansion using the ultra high speed video cameras developed recently. We also measure the chemical luminescence which is the light emission corresponding to blue flame and heat flame. Moreover, we analyze the characteristics of pre-autoignition reaction in relation to the ignition delay time and the unbumt gas temperature, which was calculated from cylinder pressure. 9637249 Analysis and Avoidance of Pre-ignition in Spark Ignition Engines Kazuhisa Mogi, Katsushi Hashizume, Katsuhikn Arisawa, Hideo Kobayashi (Toyota Motor Corp.) In spark ignition engines, there have been attempts to increase the compression ratio and to attain the mixture of stoichiometric air-fuel ratio