摘要:
A control device of a continuously variable transmission for a vehicle to which power of a drive force source is input through a transmission path connecting/disconnecting device changes a gear ratio of the continuously variable transmission to a lower vehicle speed side during vehicle deceleration when the transmission path connecting/disconnecting device is in a power transmission interrupted state of interrupting power transmission through a power transmission path between the drive force source and the continuously variable transmission, earlier as compared to when the transmission path connecting/disconnecting device is in a power transmittable state enabling the power transmission, and the control device changes a gear ratio of the continuously variable transmission earlier to the lower vehicle speed side when vehicle deceleration is larger, when the transmission path connecting/disconnecting device is in the power transmission interrupted state.
摘要:
A control device of a continuously variable transmission for a vehicle having a pair of variable pulleys with variable effective diameters of an input-side variable pulley and an output-side variable pulley and a transmission belt wound around between the pair of the variable pulleys, the continuously variable transmission respectively controlling an input-side thrust force in the input-side variable pulley and an output-side thrust force in the output-side variable pulley to set an actual gear ratio to a target gear ratio while preventing a slip of the transmission belt, the continuously variable transmission includes: a hydraulic control circuit capable of accurately controlling one of the input-side variable pulley and the output-side variable pulley in terms of thrust force as compared to the other, in the case that a target thrust force on the one side for assuring belt slip prevention of the both pulleys on the one side is set, based on a target thrust force on the one side, a target thrust force on the other side for achieving a target gear ratio on the other side being set, and a larger one being selected as the target thrust force on the one side out of a limit thrust force to a slip on the one side required for belt slip prevention on the one side, and a thrust force on the one side required for achieving a target gear ratio on the one side calculated based on a limit thrust force to a slip on the other side required for belt slip prevention on the other side.
摘要:
In a shift control device and a shift control method of an automatic transmission that establishes a plurality of gear steps of different speed change ratios by selectively engaging a plurality of friction engagement devices, one of a shift start time point and an inertia phase start time point is used as a reference time. In a power-off shift, the shift action is compulsorily ended when the elapsed time from the reference time exceeds a first time. In a power-on shift, the shift action is compulsorily ended when the elapsed time from the reference time exceeds a second time that is set shorter than the first time. If a switch from the power-off shift to the power-on shift occurs halfway through the power-off shift, the shift action is compulsorily ended when the elapsed time from the time point of the switch exceeds a predetermined time.
摘要:
In the case where a signal for coasting time downshifting is output while fuel cut is performed and fuel supply is stopped, and a hydraulic pressure PC1 of a low speed side frictional engagement device is being gradually increased and an engine speed NE is being increased, when the fuel cut is cancelled and the fuel supply is restarted, the hydraulic pressure PC1 is reduced to a hydraulic pressure value immediately before an amount of torque is applied to the low speed side frictional engagement device.
摘要:
A transmission ECU 12 determines whether or not the conditions for executing a neutral control operation are satisfied (step S11), and measures hydraulic oil temperature if it determines that the execution conditions are satisfied (step S12). Then, the transmission ECU 12 sets a target speed ratio for a torque converter 3 corresponding to the measured hydraulic oil temperature (step S13), and performs a neutral control operation to bring the speed ratio of the torque converter 3 equal to the target speed ratio (step S14).
摘要:
A control device of a vehicle drive device in which an output of a power source is input from a hydraulic power transmission device via a friction engagement device to a continuously variable transmission and transmitted toward drive wheels after speed is changed by the continuously variable transmission, the control device includes: an abnormality detecting portion configured to make a determination of abnormality indicating that the friction engagement device is in a complete release state or a slip state; and an abnormality distinguishing portion, if the abnormality detecting portion makes a determination of abnormality, configured to judge that the friction engagement device is in the slip state when an input/output rotation speed difference between an input rotation speed and an output rotation speed of the hydraulic power transmission device is equal to or greater than a predetermined slip determination value and that the friction engagement device is in the complete release state when the input/output rotation speed difference is less than the slip determination value.
摘要:
A shift control device of a vehicular automatic transmission, if during a first shift in a power-off state, a second shift judgment for a second shift that is a power-on downshift is made, performs a second shift control of lowering an input shaft rotation speed to a synchronous rotation speed of a post-second shift gear step through an engagement control of the friction engagement devices, and when the second shift is performed, performs a control of reducing a throttle valve opening degree of the engine to a predetermined degree that causes the engine to output a torque that is able to bring the input shaft rotation speed to a rotation speed that is higher than the synchronous rotation speed of the post-second shift gear step. The control device also executes a retardation control of retarding an ignition timing of the engine when the input shaft rotation speed is dropped through the second shift control.
摘要:
When downshift control is performed during fuel cut control (when coast-down gearshift control is performed), fuel cut reset revolutions are lowered and set to revolutions Ndwn that are lower than fuel cut reset revolutions Nnor for normal control. By such a setting, it becomes possible to maintain fuel cut control and deceleration lockup slippage control even when engine revolutions NE temporarily drop during execution of coast-down gearshift control, so an improvement in fuel consumption can be achieved. Moreover, it becomes unnecessary to set a downshift gearshift line to a higher vehicle speed side, so fuel cut can be maintained while suppressing the occurrence of a gearshift shock.
摘要:
The invention relates to a shift control apparatus for an automatic transmission that executes a torque reduction control when the transmission downshifts in response to a downshift determination made during an upshift. The shift control apparatus includes a multiple shift execution unit that starts the downshift in response to the downshift determination, and a torque reduction control execution unit that determines whether the rotational speed of the input member is at least a control start-up rotational speed, after the downshift operation starts, and executes a torque reduction control of the power source when the rotational speed of the input member is increased to at least the control start-up rotational speed. This allows the rotational speed of the input shaft to be quickly changed to the appropriate synchronous rotational speed. Thus, the desired driving force is provided upon completion of the downshift without overspeeding the engine.
摘要:
A shift control device of a vehicular automatic transmission that establishes a plurality of gear steps of different speed change ratios by selectively engaging a plurality of friction engagement devices ends the shift control by making an engagement end determination regarding an engagement-side friction engagement device if it has been determined continuously for a predetermined time that the input shaft rotation speed of the automatic transmission is in the vicinity of the synchronous rotation speed of the post-shift gear step. The predetermined time is set at a first time if the downshift is a power-on downshift due to a shift judgement in a power-on state, and is set at a second time that is shorter than the first time if the downshift is a power-off→on downshift selected in connection with a change to the power-on state during a power-off shift due to the shift judgment in a power-off state.