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Ito, Makoto
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Development of High Accuracy Rear A/F Sensor

DENSO Corporation-Makoto Ito, Mitsuru Sakimoto, Zhenzhou Su
Toyota Motor Corp.-Go Hayashita, Keiichiro Aoki
Published 2017-03-28 by SAE International in United States
New 2A/F systems different from usual A/F-O2 systems are being developed to cope with strict regulation of exhaust gas. In the 2A/F systems, 2A/F sensors are equipped in front and rear of a three-way catalyst. The A/F-O2 systems are ideas which use a rear O2 to detect exhaust gas leaked from three-way catalyst early and feed back. On the other hand, the 2A/F systems are ideas which use a rear A/F sensor to detect nearly stoichiometric gas discharged from the three-way catalyst accurately, and to prevent leakage of exhaust gas from the three-way catalyst. Therefore, accurate detection of nearly stoichiometric gas by the rear A/F sensor is the most importrant for the 2A/F systems. In general, the A/F sensors can be classified into two types, so called, one-cell type and two-cell type. Because the one-cell type A/F sensors don’t have hysteresis, they have potential for higher accuracy. In addition, in rear environment, because there are very much condensed water in an exhaust pipe, thimble typed sensors which are resistant to water splash are suitable. For…
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Development of High Sensitivity Oxygen Sensor

Makoto Ito, Kiyomi Kobayashi, Takehiro Watarai, Ryouzou Kayama, Takanori Sasaki
  • Technical Paper
  • 2011-08-0414
Published 2011-10-12 by Society of Automotive Engineers of Japan in Japan
Emission regulations have become stricter due to the rise of the concern to the environmental protection. The O2 sensor installed behind the three-way catalyst is required to detect the change of exhaust emission from the catalyst by the air/fuel ratio change at the early stage. Especially, the O2 sensor is required to detect NOx at early stage, because NOx is not purified easily by the catalyst and exhausted rapidly by the air/fuel ratio change. Therefore, we developed new Oxygen sensor which has high sensitivity for NOx. This paper shows catalyst layer development of Oxygen sensor as key point of new Oxygen sensor.

Improvement of Middle Engine Speed Torque By Using Resonance Effect For Restricted 600cc Four-Stroke Engine

Sophia University-Makoto Ito, Hiroyuki Yano, Yasuhumi Oguri, Takashi Suzuki
  • Technical Paper
  • 2007-32-0115
Published 2007-10-30 by Society of Automotive Engineers of Japan in Japan
This research focuses on the improvement of torque at the middle engine speed of a motorcycle engine with resonance supercharging. The resonance supercharging intake system is realized with a simple modification to the intake collector geometry. A one-dimensional computational model is employed to simulate the pressure wave propagation and to optimize the configuration of it. The experiments confirmed the increase in the engine torque for the entire operation range and the maximum gain of 33% was achieved at 8500rpm. The resonance effect is further investigated through three-dimensional simulation, in which the intake airflow rate, static pressure distribution are analyzed.
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Application to Engine Development of Friction Analysis by Piston Secondary Motion Simulation in Consideration of Cylinder Block Bore Distortion

Honda R&D Co., Ltd. Center-Kenji Sato, Kinya Fujii, Makoto Ito, Shinsuke Koda
Published 2006-04-03 by SAE International in United States
Piston skirt friction has been considered to be related to cylinder block bore distortion and piston secondary motion, but it has been studied almost exclusively in isolation, and its detailed relationship to the functioning of an actual engine has not been clarified. In an attempt to improve correlation with actual engine behavior this study evaluated piston skirt performance using computer simulation of piston secondary motion that include the effects of cylinder bore distortion, skirt stiffness and skirt form. First, calculation results of cylinder block bore distortion and piston secondary motion was compared with measurement value respectively by amount of deformation and amount of secondary motion, and that validity was confirmed. Next, the technique was applied to the development of an actual engine, and the engine performance was studied along with the establishment of a method to predict friction. The application of the new simulation technique in engine development reduced friction approximately 2%, demonstrating the effectiveness of the method. Moreover, seizing was evaluated by wear load parameter at the same time, and increase in the reliability…
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