Control device and control method for automatic transmission for vehicle
AssigneeJapan Electronic Control Systems Co., Ltd.
InventorsMasuo Kashiwabara, Akira Shimizu
Life of this patent
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Abstract
In a driving zone where a torque converter is to be locked up, a lockup force of a lockup clutch is weakened in the deceleration driving state compared with that in the non-deceleration driving state. Moreover, during transition from the deceleration driving state to the non-deceleration driving state, increase control of the lockup force is forcedly delayed for a predetermined time. By this, during acceleration from the deceleration driving state, the clutch is made to slip with a rapid increase in engine output torque and a rise in the engine output torque is buffered by the lockup clutch.
Claims18
A control device for an automatic transmission for a vehicle comprising:
- a torque converter placed between an output shaft of an engine and an input shaft of a gear type transmission;
- a lockup clutch for mechanically and directly engaging the input shaft with the output shaft of said torque converter;
- a deceleration detecting means for detecting a deceleration driving state of the engine;
- a non-deceleration detecting means for detecting a non-deceleration state of the engine;
- a control value switching means for switching and setting a lockup force control value of said lockup clutch so that a lockup force in the deceleration driving state detected by said deceleration driving detecting means is smaller than a lockup force in the non-deceleration driving state;
- a lockup control means for controlling lockup of said lockup clutch based on said lockup force control value in a predetermined driving zone including at least a deceleration driving zone;
- and
- a lockup force increase restraining means for forcedly delaying a rise in a lockup force of the lockup clutch during transition from the deceleration driving state to the non-deceleration driving state.
A control method for controlling an automatic transmission for a vehicle, wherein a lockup clutch is provided for mechanically and directly engaging an input shaft with an output shaft of a torque converter placed between an output shaft of an engine and an input shaft of a gear type transmission, comprising:
- a step for detecting a deceleration driving state and a non-deceleration driving state;
- a step for sensing a lockup force of the lockup clutch;
- a step for switching and controlling the lockup force of the lockup clutch so that the lockup force in the deceleration driving state of the engine is smaller than the lockup force in the non-deceleration driving state;
- and
- a step for forcedly delaying a rise in the lockup force of the lockup clutch during a transition from the deceleration driving state to the non-deceleration driving state.
Dependencies are inferred from the claim text.