24 巻 (2016) 6 号 p. 40-48
Control of engine cylinder bore wall temperature is an important issue:at low temperatures, there is a risk of corrosion due to sulfuric acid resulting from condensation of combustion moisture;if the temperature is too high, however, there are other risks, such as piston seizure. A study of the reduction of bore wall temperature variation was therefore made, using a simplified temperature simulation in which bore wall temperature due to combustion in the engine was the quality characteristic, with two signal factors and with time and place as indicative factors. As a result, optimal collditions were found that improved cooling efficiency while reducing temperature differences between different sites. From a detailed interaction analysis, the factors that affect bore wall temperature were clarified and an inductive analysis was carried out, showing that the cooling water flow rate by itself affected the bore wall temperature and that the effect of differences in water temperature due to driving conditions could not be changed by design strategies.