Abstract:
When a torque converter (2) is being switched from a slip engagement state to a full engagement state as a result of an ON operation of an accelerator, during the execution of control that achieves the full engagement state after increasing the rotation of an internal combustion engine (1) in the slip engagement state while expanding the torque transmission capacity of a lockup clutch (20) by means of slip engagement, if it is determined that there has been a gain in the output torque of the internal combustion engine (1) when, within a prescribed period of time after the beginning of the control, the detected input/output differential rotation speed of the lockup clutch (20) is at or below a second prescribed value (ΔN2) that is smaller than a first prescribed value (ΔN1) after having increased to or above the first prescribed value, a prescribed capacity is added to the expanding torque transmission capacity of the lockup clutch (20). It is possible to avoid judder variation caused by the release of an accelerator pedal during a transition to a lockup state.
Abstract:
[Summary] A control device for a lock-up-clutch (20) installed in a torque converter (2) arranged between a prime mover (1) serving as a driving source and an automatic transmission mechanism (4) is described, the control device including an engagement control means (8H) that carries out a calculation to increase an engaging capacity of the lock-up-clutch (20) with the passage of time during an engagement control time in which the torque converter (2) is shifted from a converter condition to a lock-up condition, the prime mover (1) driving an auxiliary device (110), in which when, during the control to increase the engaging capacity of the lock-up-clutch (20), an input torque inputted to the torque converter from the prime mover (1) is increased due to reduction in load of the auxiliary device (110), the engagement control means (8H) promotes the increase of the engaging capacity of the lock-up-clutch (20) based on the amount of increase of the input torque. According to the control device for the lock-up-clutch of the present invention, the pressure shortage that would be induced in the period toward the lock-up condition is assuredly eliminated.
Abstract:
First temporary capacity reduction control that when acceleration ON is judged during coasting lock-up, brings lock-up clutch (20) into slip state by decreasing torque transmission capacity of lock-up clutch and subsequently returns lock-up clutch to lock-up state by increasing torque transmission capacity is executed. Control unit performing second temporary capacity reduction control that when return of accelerator pedal depression is judged during the progress of returning to lock-up state, decreases torque transmission capacity again and subsequently returns lock-up clutch to lock-up state by increasing torque transmission capacity is provided. In second temporary capacity reduction control, torque transmission capacity is decreased with predetermined torque transmission capacity by which lock-up clutch is not fully disengaged being lower limit value. Abrupt engagement of lock-up clutch and engine racing can be therefore avoided when acceleration is changed from ON to OFF during control of lock-up clutch from disengagement or slip state to lock-up state.
Abstract:
First temporary capacity reduction control that when acceleration ON is judged during coasting lock-up, brings lock-up clutch (20) into slip state by decreasing torque transmission capacity of lock-up clutch and subsequently returns lock-up clutch to lock-up state by increasing torque transmission capacity is executed. Control unit performing second temporary capacity reduction control that when return of accelerator pedal depression is judged during the progress of returning to lock-up state, decreases torque transmission capacity again and subsequently returns lock-up clutch to lock-up state by increasing torque transmission capacity is provided. In second temporary capacity reduction control, torque transmission capacity is decreased with predetermined torque transmission capacity by which lock-up clutch is not fully disengaged being lower limit value. Abrupt engagement of lock-up clutch and engine racing can be therefore avoided when acceleration is changed from ON to OFF during control of lock-up clutch from disengagement or slip state to lock-up state.
Abstract:
A start request detection unit detects a start request for a vehicle. A hydraulic pressure control circuit controls torque transmitted by a lock-up clutch by controlling an engagement force of the lock-up clutch. A rotation speed detection unit detects an output rotation speed of a torque converter. An engagement control unit issues an instruction to the hydraulic pressure control circuit such that the lock-up clutch is placed in slip engagement and is able to transmit the torque when the following conditions are both satisfied: a predetermined time period has elapsed since detection of the start request by the start request detection unit; and the output rotation speed has increased to a predetermined rotation speed or higher.
Abstract:
A device for controlling a start of a vehicle includes a rotation speed obtaining unit that obtains an actual engine rotation speed of the engine, a target rotation speed computing unit that computes a target rotation speed of the engine in the slip control, a control target value computing unit that computes a control target value, which is a target value for controlling the engine rotation speed to the target rotation speed based on the actual engine rotation speed and the target rotation speed, and an instruction value computing unit that computes an instruction value for the lock-up clutch necessary to control the engine rotation speed to the control target value based on the control target value.
Abstract:
When a torque converter (2) is being returned to a full engagement state as a result of an ON operation of an accelerator after temporary disengagement of the full engagement state, during the execution of control that achieves the full engagement state after increasing the rotation of an internal combustion engine (1) by means of slip engagement while expanding the torque transmission capacity of a lockup clutch (20), if it is determined that there has been a gain in the output torque of the internal combustion engine (1) when, within a prescribed period of time after the beginning of the control, the detected input/output differential rotation speed of the lockup clutch (20) is at or below a second prescribed value (ΔN2) that is smaller than a first prescribed value (ΔN1) after having increased to or above the first prescribed value, a prescribed capacity is added to the expanding torque transmission capacity of the lockup clutch (20). It is possible to avoid judder vibration caused by the release of an accelerator pedal during a transition to a lockup state.