Search Results

The purpose of this research was to predict the amount of wear on exhaust valve seats in durability testing of gasoline engines. Through the rig wear test, a prediction formula was constructed with multiple factors as variables. In the rig test, the wear rate was measured in some cases where a number of factors of valve seat wear were within a certain range. Through these tests, sensitivity for each factor was determined from the measured wear data, and then a prediction formula for calculating the amount of wear was constructed with high sensitivity factors. Combining the wear amount calculation formula with the operation mode of the actual engine, the wear amount in that mode can be calculated. The calculated wear amount showed a high correlation with the wear amount measured in bench tests and the wear amount measured in vehicle tests.

Various deformation shapes of the vehicle body were investigated for the purpose to establish vehicle body's performance criteria which correlates well to handling performance and ride comfort. Using evaluations by experienced test driver, the fact that the rigidity of each body deformation correlated well to different dynamic performance was found. With careful verification test, simple lateral frequency response was chosen as the criteria for handling performance and vertical response was chosen for ride comfort. These were applied to the development of our recent production vehicle body. Finite element analysis simulation with these criteria helped to make new construction to meet body performance targets with minimum weight during planning-stage of the development. Also, the targets of ride comfort and handling performance of actual vehicle were accomplished with very little structural change during the testing and improvement stage of the vehicle development.