Power transmission system for vehicle
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsKeigo Matsubara, Ayumu Sagawa
Life of this patent
Estimating the term…
Abstract
If the difference between output torque output from an engine and load torque from drive wheels is large and torque input to a lockup clutch is large, since a value of lockup command pressure at which lockup engagement pressure in lockup end control becomes constant standby pressure is set to be high, fast release of the lockup clutch or racing of the engine is suppressed during the lockup end control. If torque input to the lockup clutch is small, the value of the lockup command pressure at which the lockup engagement pressure in the lockup end control becomes the constant standby pressure is set to be low, and a hydraulic pressure output period during which hydraulic pressure is output to the lockup clutch is set to be short.
Claims5
A power transmission system for a vehicle, the power transmission system comprising:
- a transmission;
- a torque converter provided between the transmission and a power source;
- a lockup clutch configured to directly connect an input member and an output member of the torque converter with supply of control hydraulic pressure to a control oil chamber;
- and
- an electronic control unit configured to:
- (i) execute lockup end control that decreases the control hydraulic pressure to release the lockup clutch, and
- (ii) make end control initial hydraulic pressure of the lockup end control higher as a difference between output torque and driven torque is larger, when the electronic control unit determines that the execution of the lockup end control starts, the output torque being output from the power source when the electronic control unit determines that the execution of the lockup end control starts, the driven torque being supplied from drive wheels.
Dependencies are inferred from the claim text.