To manufacture a power transmission system in a vehicle power plant so as to have a capacity suitable for economy, as well as to protect it from overload at the high torque loaded operation.
An engine 12 is drivingly connected through a clutch 16 to a power transmission system 11 including a multi-step gear transmission 14 and a final power transmission system 19. A system controller 48 and a controller 36 control the fuel supplied to the engine. The multi-step gear transmission 14 is produced to be economically suitable for maximum torque loading capacity less than the maximum output torque of the engine 12. The system controller 48 and the controller 36 detects the transmission gear ratio GR and the output shaft speed OS as control parameters indicative of possible high loaded operation leading to the overload beyond maximum torque load capacity of the transmission 11 at the engine maximum output torque, to limit the output torque of the engine 12 to be less than that maximum output torque to protect the transmission 11.
DANIERU JIYOOJI SUMEDERII
RATSUSERU KURAIDO HORUMUZU
TOOMASU AASAA GII
