摘要:
A system for controlling an automatic transmission of a vehicle, wherein the initial value of the desired pressure to be supplied to a hydraulic clutch for the current gear now being engaged is determined appropriately, when conducting a power-on downshifting, so as to decrease the shift shock experienced by the vehicle occupant effectively, irrespectively of the change in the throttle opening, while ensuring to reduce the volume of the mapped data.
摘要:
A system for controlling an automatic transmission of a vehicle, wherein the hydraulic pressure to be supplied to the frictional engaging element such as a hydraulic clutch is determined, taking the performance of tracking or follow-up of the hydraulic pressure into account so as to enhance the control toughness against the engine speed change, thereby decreasing the shift shock effectively so as to improve the feeling of the vehicle occupant, while ensuring to prevent the engine from revving over or excessively. Further, the friction coefficient of the hydraulic clutch is calculated additionally taking parameters including the rotational difference thereof into account to determine the pressure to be supplied to the frictional engaging element, thereby further decreasing the shift shock effectively.
摘要:
A system for controlling an automatic transmission of a vehicle, in which a pressure supply time to complete removal of the clutch-stroke play is determined based on the input shaft rotational speed. And a residual oil amount in the clutch is estimated and the time is corrected by the residual oil amount. The preparatory pressure to be supplied within the time is also determined based on the input shaft rotational speed and the ATF temperature. With this, it becomes possible to effect the clutch-stroke play removal within a less variant time and with a good response, thereby decreasing the shift shock effectively so as to improve the feeling of the vehicle occupant.
摘要:
A system for controlling an automatic transmission of a vehicle, wherein a pressure to be supplied to the hydraulic clutch of a target gear is determined based on a desired value of acceleration of gravity acting in the longitudinal direction of the vehicle and other parameters including an engine torque, thereby decreasing the shift shock effectively, while ensuring to finish the shift within an expected period of time. Moreover, the engine torque is estimated using a parameter indicative of inertia torque used for raising the engine speed. With this, it becomes possible to determine the engine torque inputted to the transmission, thereby decreasing the shift shock more effectively.
摘要:
A lock-up control device controls an engaging force of a lock-up clutch, which shares engine output with a torque converter to transmit it toward an input shaft of a transmission of a car. First, target driving force is produced based on accelerator pedal opening and car velocity. Then, required torque is produced based on a gear ratio and the target driving force. Target engine speed is produced based on the required torque, wherein the target engine speed is set to avoid occurrence of abnormal sounds and abnormal vibrations. Thus, the lock-up clutch is controlled in such a way that real engine speed does not become less than the target engine speed in case of a gear change corresponding to a shift-up operation, for example. Basically, the lock-up clutch is controlled to have engaging force, which is made as maximal as possible to improve fuel efficiency. In other words, the lock-up clutch is controlled to be as tightly as possible. Or, the lock-up clutch which is initially set at a tight state is turned off just after the gear change start timing if it is predicted that the real engine speed after the gear change will become lower than the target engine speed.
摘要:
A down-shift control system is provided, by which if sufficient torque cannot be obtained for an acceleration request or intention at a shift position, a down-shift operation is suitably performed so as to realize a reliable driving capability and no shift-busy phenomenon occurs. The system includes a section for calculating target driving force of a vehicle according to a degree of opening of an accelerator pedal and a speed of the vehicle; a section for detecting the present shift position of the vehicle; a section for calculating target engine torque based on the target driving force and the present shift position; a section for comparing the target engine torque with a set value determined according to torque characteristics of the engine; a section for performing an accumulating operation relating to the degree of opening if it is judged that the target engine torque equals or exceeds the set value; and a section for outputting a down-shift command if the accumulated value exceeds a threshold relating to the degree of opening.
摘要:
In order to improve the fuel consumption by maintaining the lock-up clutch as tightly as possible during the down-shift operation, a lock-up clutch control apparatus is provided. The lock-up clutch control apparatus comprises a revolution control device for predicting the number of revolutions of the an input axis of transmission and the number of revolutions of an engine after the speed change before a down-shift operation; a torque converter judgement device for judging the state of the torque converter in terms of whether or not a torque ratio of the torque converter will be in the torque amplification range when the lock-up clutch is turned off, from the number of revolution of the input axis of the transmission and the engine speed obtained by the revolution prediction device; and a control device for turning off the lock-up clutch, if the lock-up clutch before the speed change is in a tight condition, in the case when the judgement device judges that the torque converter will be in the torque amplification range when the lock-up clutch is turned off.
摘要:
A system for controlling an automatic transmission of a vehicle, wherein if the change of the destined gear GB (i.e., the target gear SH) is required when the jumping shift, i.e., two-gear downshifting is in progress, the input/output rotational speed ratio GRATIO (indicative of degree of shift progress) is compared with the predetermined input/output rotational speed ratio #GRCN312 or #GRCN423, and based on the result of comparison, how the shift to establish or effect the required destined gear GB, i.e., the shift mode QATNUM is determined, thereby enabling to improve or enhance the response to the change of the destined gear GB during two-gear downshifting. It can also prevent the clutch from being degraded in such a shifting.
摘要:
A shift control apparatus comprises clutches driven by shift solenoids and whether or not the raising of the rotation speed occurs in an internal combustion engine is determined. If the raising of the engine rotation speed is detected, a hydraulic pressure learn correction is made to engagement hydraulic pressure and a time learn correction is made to the hydraulic pressure supply preparation time. The correction ratio of the energization-hydraulic pressure characteristic (I-P characteristic) of clutch clearance and the shift solenoid is set so as to become an appropriate distribution ratio and the learning is started based thereon.
摘要:
A throttle controller is provided so as to reduce a load imposed on the drive and transmission system in the stall state in which both the accelerator and brake are depressed. The controller comprises a throttle control section for calculating a degree of opening of the throttle for generating a driving force in accordance with the actual degree of depression of the accelerator used as a target degree of opening of the throttle so as to drive the vehicle by a target driving force calculated based on the actual degree of depression of the accelerator; a section for determining the stall state in which the gear lever is in a driving gear; the actual degree of depression of the accelerator is larger than a predetermined degree; the brake is operated; and the speed is smaller than a predetermined speed; and a storage section for storing a predetermined degree of opening of the throttle which is read out when the actual degree of depression of the accelerator is larger than the predetermined degree, and wherein the throttle control section limits the target degree of opening of the throttle to the predetermined degree stored in the storage section when the stall state of the vehicle is determined.