FLUID POWER TRANSMISSION DEVICE WITH LOCKUP CLUTCH

摘要

Drivability is improved by generating a maximum engine torque at the time of origination. A lockup clutch (30) for altering a power transmission path is arranged in parallel with the power transmission path between the pump impeller (11) and the turbine runner (13) of a fluid coupling (10) arranged between the drive side and the load side, a stall capacity coefficient Cs[N m/rpm2] is determined based on an engine r.p.m. generating a maximum engine torque Tmax on the drive side, and used for transmitting rotation on the drive side to the load side. Best accelerability is obtained by setting the stall capacity coefficient Cs such that the stall r.p.m. approaches the r.p.m. for generating a maximum engine torque, drivability is improved by a quantity of control not causing strange feeling between the quantity of stepping an accelerator and the vehicle speed, and the mileage can be enhanced.