Abstract: The first setting value showing holding pressure for a metal belt is set for each of a plurality of control modes A to H. The second setting value changing lagging behind the first setting value is calculated based on the first setting value for each of the plurality of control modes A to H. A target value is set to be equal to or more than the greatest second setting value among a plurality of second setting values. A continuously variable transmission is controlled such that the holding pressure for the metal belt is equal to the set target value.

Abstract: In a shift control device for a vehicular continuously variable transmission with an arrangement in which a normal shift mode is switched to an acceleration shift mode in response to an acceleration demand, a shift control is performed to prevent deterioration to running performance due to a transition to the acceleration shift mode by increased running resistance such as ascending road running or the like against a driver will. An acceleration demand determining value PAPL is set depending on a road surface gradient ? such that the shifting mode is more difficult to be switched to the acceleration shift mode in a larger road surface gradient ?, than in a smaller road surface gradient ?.

Abstract: In a controller for a belt-type continuously variable transmission including a hydraulic actuator that changes a groove width of a primary pulley, a hydraulic actuator that changes a groove width of a secondary pulley, and a belt clamping pressure control solenoid that controls the hydraulic pressure supplied to the hydraulic actuator of the secondary pulley, a mechanism calculates a transmission ratio between the primary pulley and the secondary pulley and determines whether or not there is belt slippage based on that calculated transmission ratio, and a mechanism determines normalcy of the belt clamping pressure control solenoid. The input torque when belt slippage has actually occurred, i.e., when a failure has been determined, is used as a condition when performing the normalcy determination.

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: The first setting value showing holding pressure for a metal belt is set for each of a plurality of control modes A to H. The second setting value changing lagging behind the first setting value is calculated based on the first setting value for each of the plurality of control modes A to H. A target value is set to be equal to or more than the greatest second setting value among a plurality of second setting values. A continuously variable transmission is controlled such that the holding pressure for the metal belt is equal to the set target value.

Abstract: An ECU executes a program including the steps of determining that a change speed solenoid is abnormal when a target speed ratio falls within a predetermined range, an upshift is recognized and the change speed solenoid is abnormal; determining that the change speed solenoid is normal when the change speed solenoid is not abnormal; determining that a belt pinch pressure solenoid is abnormal when the target speed ratio is substantially equal to a speed ratio ?min on a maximum speed-increase side and the target speed ratio is not substantially equal to an actual speed ratio; and determining that the belt pinch pressure solenoid is normal when the target speed ratio is substantially equal to the actual speed ratio.

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: An ECU executes a program including the steps of determining that a change speed solenoid is abnormal when a target speed ratio falls within a predetermined range, an upshift is recognized and the change speed solenoid is abnormal; determining that the change speed solenoid is normal when the change speed solenoid is not abnormal; determining that a belt pinch pressure solenoid is abnormal when the target speed ratio is substantially equal to a speed ratio ?min on a maximum speed-increase side and the target speed ratio is not substantially equal to an actual speed ratio; and determining that the belt pinch pressure solenoid is normal when the target speed ratio is substantially equal to the actual speed ratio.

Abstract: In a shift control device for a vehicular continuously variable transmission with an arrangement in which a normal shift mode is switched to an acceleration shift mode in response to an acceleration demand, a shift control is performed to prevent deterioration to running performance due to a transition to the acceleration shift mode by increased running resistance such as ascending road running or the like against a driver will. An acceleration demand determining value PAPL is set depending on a road surface gradient ? such that the shifting mode is more difficult to be switched to the acceleration shift mode in a larger road surface gradient ?, than in a smaller road surface gradient ?. Such arrangement prevents the shift mode from being switched to the acceleration shift mode during ascending road running with an increase in an accelerator operation amount PAP against the driver will.

Abstract: In an embodiment of the continuously variable transmission control apparatus of the present invention, even if an actual gear change ratio RATIO overshoots a target gear change ratio RATIO T and an upshift gear change instruction (DS1 gear change duty output) is switched to a downshift gear change instruction (DS2 gear change duty output) during gear change due to the upshift gear change instruction, in the case where the upshift gear change speed is fast, specifically, in the case where a maximum actual sheave position change ratio DWDRmax is not less than a determination threshold g, it is determined that the transmission is capable of performing an upshift gear change, and the upshift gear change state is determined to be normal. In this manner, a normalcy determination is performed more frequently.

Abstract: In a controller for a belt-type continuously variable transmission including a hydraulic actuator that changes a groove width of a primary pulley, a hydraulic actuator that changes a groove width of a secondary pulley, and a belt clamping pressure control solenoid that controls the hydraulic pressure supplied to the hydraulic actuator of the secondary pulley, a mechanism calculates a transmission ratio between the primary pulley and the secondary pulley and determines whether or not there is belt slippage based on that calculated transmission ratio, and a mechanism determines normalcy of the belt clamping pressure control solenoid. The input torque when belt slippage has actually occurred, i.e., when a failure has been determined, is used as a condition when performing the normalcy determination.

Abstract: A maximum flow calculating unit calculates a maximum amount of hydraulic fluid that can flow into or out of an input-side hydraulic cylinder when a shift control command signal is set to a reference DUTY value, based on an estimated valve pressure difference calculated by an estimated pressure difference calculating unit, and a post-guard target sheave position setting unit performs a guard process for restricting the amount of change of the sheave position, using a guard value calculated by a guard value calculating unit based on the maximum flow amount, so as to set a post-guard target sheave position. Since the thus set target sheave position does not undergo excessive large changes nor excessively small changes during shifting, a target value for shifting is set so that a feedforward controlled variable determined based on the amount of change of the target sheave position becomes an appropriate value.

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 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 speed-ratio control apparatus for controlling a speed ratio of a continuously variable transmission of a vehicle, such that an actual input speed of the transmission coincides with a target input speed, the apparatus including an acceleration-requirement determining portion operable to determine whether non-rapid acceleration or rapid acceleration of the vehicle is required by a vehicle operator, and a target-input-speed setting portion operable, upon determination of the operator's requirement for the non-rapid acceleration, to implement an instantaneous stepping increase of the target input speed to a first transient target value, (ii) hold the target input speed at the first transient target value in a first portion of a rapid shifting period, (iii) instantaneously reduce, at the end of the first portion of the rapid shifting period, the target input speed to an initial value of a second transient target value which initial value is close to the actual input speed and lower than the first transient targe

Abstract: A maximum flow calculating unit calculates a maximum amount of hydraulic fluid that can flow into or out of an input-side hydraulic cylinder when a shift control command signal is set to a reference DUTY value, based on an estimated valve pressure difference calculated by an estimated pressure difference calculating unit, and a post-guard target sheave position setting unit performs a guard process for restricting the amount of change of the sheave position, using a guard value calculated by a guard value calculating unit based on the maximum flow amount, so as to set a post-guard target sheave position. Since the thus set target sheave position does not undergo excessive large changes nor excessively small changes during shifting, a target value for shifting is set so that a feedforward controlled variable determined based on the amount of change of the target sheave position becomes an appropriate value.

Abstract: The line oil pressure PL that is a basic pressure of a needed Pin pressure and a Pd pressure is set by line oil pressure setting device on the basis of the higher oil pressure of the oil pressure values obtained by adding reference margin values EX to the needed Pin pressure and the to Pd pressure. Therefore, a requirement minimum line oil pressure PL with respect to the needed Pin pressure needed for shifting and the Pd pressure needed for the belt clamping pressure is appropriately set so that good shifting performance and good belt clamping pressure are secured.

Abstract: A speed-ratio control apparatus for controlling a speed ratio of a continuously variable transmission of a vehicle, such that an actual input speed of the transmission coincides with a target input speed, the apparatus including an acceleration-requirement determining portion operable to determine whether non-rapid acceleration or rapid acceleration of the vehicle is required by a vehicle operator, and a target-input-speed setting portion operable, upon determination of the operator's requirement for the non-rapid acceleration, to implement an instantaneous stepping increase of the target input speed to a first transient target value, (ii) hold the target input speed at the first transient target value in a first portion of a rapid shifting period, (iii) instantaneously reduce, at the end of the first portion of the rapid shifting period, the target input speed to an initial value of a second transient target value which initial value is close to the actual input speed and lower than the first transient targe