Abstract:
One control mode is selected from a plurality of control modes each setting a target value of a primary pulley revolution speed NIN and prioritized in a predetermined order. When the control mode is changed, the target value of the primary pulley revolution speed NIN is set so as to vary from the target value set in the control mode before change to the target value set in the control mode after change in accordance with the control mode that is higher in priority among the control modes before and after change. A continuously variable transmission is controlled such that the primary pulley revolution speed NIN reaches the set target value.
Abstract:
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.
Abstract:
A control device of a continuously variable transmission that controls an input-side thrust force of an input-side variable pulley and an output-side thrust force of an output-side variable pulley to set an actual gear ratio to a target gear ratio and prevent a slip of the transmission belt. The continuously variable transmission having a lowest-speed-side gear ratio determined by mechanically preventing movement of an input-side rotating body moved in an axial direction for varying an effective diameter of the input-side variable pulley, if it is determined that a detection value of a rotation speed for calculating the actual gear ratio does not reflect an actual rotation speed, a target input-side thrust force and a target output-side thrust force being set to be target thrust forces for maintaining the lowest-speed-side gear ratio and preventing a slip of the transmission belt, and, based on whether the actual gear ratio is already the lowest-speed-side gear ratio, the control device differentiating control methods of the input-side thrust force and the output-side thrust force each of which is independently controllable to adjust a pressure in order to obtain the target thrust.
Abstract:
A diagnostic apparatus and a diagnostic method are provided for a belt squeezing force adjusting mechanism of a continuously variable transmission in which a belt is wound around a primary sheave that receives driving force and a secondary sheave that outputs force to a drive line, and which continuously changes the output rotation speed by adjusting the width of the groove the primary sheave and the secondary sheave by shift control. This diagnostic determines, as a precondition, whether a target control value calculated in shift control is in a low region, and performs a diagnostic on the belt squeezing force adjusting mechanism based on the relationship between an actual control value and the target control value during control to reduce a control value when it is determined that the precondition is satisfied. According to this diagnostic apparatus and diagnostic method, an erroneous diagnosis can be prevented so the diagnostic can be performed accurately.
Abstract:
A vehicular shift control apparatus configured to control a speed ratio of a belt-type transmission having first and second variable-diameter pulleys, and a transmission belt wound between the first and second variable-diameter pulleys, by controlling hydraulic pressures to be applied to respective hydraulic cylinders of said first and second variable-diameter pulleys, according to respective commanded hydraulic pressure values of the first and second variable-diameter pulleys, such that the speed ratio coincides with a target value, the vehicular shift control apparatus includes a shift control portion configured to be operable, when a first-variable-diameter-pulley hold pressure which permits the speed ratio of said belt-type transmission to be held at the target value in a shift-down action is determined as said commanded hydraulic pressure value of the first variable-diameter pulley, to temporarily reduce said commanded hydraulic pressure value with respect to said first-variable-diameter-pulley hold pressure in an initial period of said shift-down action.
Abstract:
One control mode is selected from a plurality of control modes each setting a target value of a primary pulley revolution speed NIN and prioritized in a predetermined order. When the control mode is changed, the target value of the primary pulley revolution speed NIN is set so as to vary from the target value set in the control mode before change to the target value set in the control mode after change in accordance with the control mode that is higher in priority among the control modes before and after change. A continuously variable transmission is controlled such that the primary pulley revolution speed NIN reaches the set target value.
Abstract:
The line hydraulic pressure setting portion sets the line hydraulic pressure PL, which is the base pressure for the required shift control pressure Pin and the required belt clamping pressure Pd, based on the higher of the required pressures Pin and Pd. At this time, if the continuously variable transmission is to be shifted up, the required Pin calculating portion calculates the required shift control pressure Pin based on one of the target speed ratio γ* and the actual speed ratio γ with which the required shift pressure Pv is calculated to be higher than with the other. As such, the required shift control pressure Pin is set to the minimum necessary level for shifting up the continuously variable transmission and the line hydraulic pressure PL is appropriately set to a level for obtaining the required shift control pressure Pin.
Abstract:
A control device for an automatic transmission 10 having shift control means 88 operative to select a manual shift mode is provided for preventing acceleration response from deteriorating in the automatic transmission 10. The control device includes automatic up-range control means 90 for switching a range to a “D” range when high oil-temperature determining means determines presence of a high oil-temperature state, and high oil-temperature down-range permitting means 92 for permitting a down-range during a manual shift operation until a selected uppermost gear position GSELECT reaches a determining gear position GJUGE when the accelerator-on drive determining means 86 subsequently determines presence of an accelerator-on drive. Even when obtaining a drive force is attempted during an accelerator-on drive mode after switching the range, the down-range by the manual shift operation is permitted until the selected uppermost gear position GSELECT reaches the determining gear position GJUGE. Thus, a drop in acceleration response in comparison to that of an automatic shift mode is prevented.
Abstract:
The invention provides a shift control apparatus of a continuously variable transmission, which includes a feedback control portion which executes feedback control that brings an actual speed ratio close or equal to a target speed ratio, and a normal operation determining portion which determines whether the shift control apparatus is operating normally based on a difference between the actual speed ratio and the target speed ratio, and an amount of change in the actual speed ratio and an amount of change in the target speed ratio during a predetermined interval.
Abstract:
A lock-up control system for a torque converter which includes a lock-up clutch engageable under control of an engaging capacity of the lock-up clutch to thereby lock up input and output elements of the torque converter. The control system is operative during coasting in a lock-up region requiring engagement of the lock-up clutch, so as to bring the engaging capacity of the lock-up clutch to a coast lockup capacity smaller than a lock-up capacity under a driving condition at the same vehicle speed. The control system is further operative when an engine braking range is selected during coasting in the lock-up region, so as to bring the engaging capacity of the lock-up clutch to a value greater than the coast lock-up capacity, preferably to a controlling maximum value.