1990 Volume 52 Issue 1 Pages 3-10
A system consisting of an engine, a transmission and an equipment was discussed in the previous papers to achieve efficient and easy driving at the highest fuel efficiency state. In order to introduce this controlling method to actual tractor systems, the engine performance and “optimal operation curve” were studied in this paper. Ten tractors manufactured by four Japanese companies were tested by using the PTO test equipment with a computer measuring system. Even if all the engines were new types and had almost the same rated output in their catalogues, there were significant differences between their performances. Through the analysis on the governor mechanism and the fuel supply of every stroke of injection pump, it was clarified that these differences were caused by the utilization of different angliech or torque spring apparatus.
Moreover, it was known that the optimal operation curve should be modified according to not only the fuel consumption characteristics but also the engine operation characteristics.
