Development of instrument for measurement of fuel–air ratio in vicinity of spark plug: application to DI gasoline engine

An instrument to measure time-resolved fuel–air ratio in the vicinity of a spark plug was developed. Properties of absorption and scattering at the wavelengths of visible and infrared rays were utilized to determine the fuel–air ratio in the mixture including liquid and vaporized fuel. The measurement error of the instrument was within 10% as a result of comparison between the overall and the measured fuel–air ratio at the vicinity of the spark plug under the inlet port injection, which forms a relatively homogeneous mixture. The instrument was applied to a direct injection gasoline engine and the mixture formation process was clarified.     

Study on the measurement of oil-film pressure of engine main bearing by thin-film sensor — The influence of bearing deformation on pressure sensor output under engine operation

In a previous paper, oil-film pressure in an engine main bearing was measured by a using thin-film Manganin sensor. This sensor had adequate sensitivity to strain and temperature in terms of measurement principle. In this study, more accurate measurement of oil-film pressure was allowed by the formation of the newly developed thin-film strain sensor made of Ni-Cr-Al at the same location as that of the Manganin pressure sensor, and the correction of measurement errors caused by strain. The characteristics of bearing metal surface strain varied by engine operating conditions are also shown in this paper.