Abstract:
In control apparatus and method for an automotive vehicle, the vehicle having a continuously variable transmission associated with a vehicular engine and including a belt that transmits a revolution of a primary pulley to a secondary pulley that is enabled to make a gear shift by modifying a pulley ratio between the primary and secondary pulleys with a hydraulic, a determination is made as to whether a belt slip between at least one of the primary and the secondary pulleys occurs and an output section outputs a signal to command an engine control unit to increase an engine speed by a predetermined engine speed when the belt slip is determined to occur.
Abstract:
Hydraulic control apparatus includes a belt-drive CVT, a pressure regulator valve (P.REG.V) regulating the oil pressure produced by an oil pressure source, a controller programmed to develop a transmission control signal, a transmission actuator driven based on the signal, and a transmission control valve actuated by the actuator. There are provided a first oil passage for supplying an oil pressure regulated by the P.REG.V, a second oil passage for supplying the oil pressure regulated to a primary pulley cylinder chamber of the CVT and draining the oil pressure therefrom, a third oil passage for draining the oil pressure within the cylinder chamber, and a fourth oil passage downstream of the P.REG.V. The third and fourth oil passages are connected to supply an oil pressure to the cylinder chamber and establish a minimum oil pressure required for clamping the belt depending on reduction of the oil pressure within the cylinder chamber.
Abstract:
A lock-up control device comprises an inlet circuit which supplies oil to a torque converter chamber, an outlet circuit which discharges oil from the torque converter chamber, a signal output circuit which outputs a signal pressure according to a required engaging capacity of a lock-up clutch, and a lock-up control valve which outputs a lock-up control pressure according to the signal pressure from the signal output device. A lock-up control pressure which is fed back is input to the lock-up control valve so as to decrease the lock-up control pressure, and the pressure of the inlet circuit and pressure of the outlet circuit are input to the lock-up control valve so as to increase the lock-up control pressure. In this way, the pressure in the converter chamber is accurately reflected, and the lock-up control pressure is controlled so that a pressure differential between the lock-up control pressure and the torque converter chamber is a desired value.
Abstract:
A hydraulic control apparatus for an automatic transmission with a line pressure regulator valve operative to regulate an oil pressure produced by an oil pump and set a line pressure, the hydraulic control apparatus including a control unit outputting a first command for controlling the line pressure regulator valve to set the line pressure to a minimum value immediately after engine start, and a second command for controlling the line pressure regulator valve to set the line pressure to a target value in accordance with increase in engine speed. The control unit is programmed to set the target value of the line pressure to a value smaller than a maximum value of the line pressure and/or reduce a target speed of engine speed, upon start of the engine in a low temperature condition.
Abstract:
In hydraulic pressure control apparatus and method for a continuously variable transmission, a line pressure of the continuously variable transmission is developed with a working oil supplied from an oil pump as an original pressure, and a command pressure is set to develop a line pressure target value of the target value in such a manner that the command pressure is maintained at a predetermined small value for a constant time and, thereafter, the value of the command pressure is raised up to the target value when a shift range of the continuously variable transmission is switched from a neutral range to a running range, the command pressure being raised at a rate lower than a step input to suppress an overshoot developed in the actual line pressure.
Abstract:
In corrective control system and method for a liquid pressure control apparatus for a control valve unit, fundamental maps are preset on the basis of a hysterisis characteristic, the hysterisis characteristic being exhibited in such a manner that an output liquid pressure actually measured value which takes along a first hysterisis loop when the current value is increased toward a larger value is different from that which takes along a second hysterisis loop when the current value is, in turn, decreased toward a smaller value from the larger value and each fundamental map is a map representing a relationship between the output liquid pressure actually measured value and a current average value, the current average value being an average between the current value in the first hysterisis loop and that in the second hysterisis loop with respect to each of the same output pressure actually measured values.
Abstract:
In hydraulic pressure control apparatus and method for a continuously variable transmission, a line pressure of the continuously variable transmission is developed with a working oil supplied from an oil pump as an original pressure, and a command pressure is set to develop a line pressure target value of the target value in such a manner that the command pressure is maintained at a predetermined small value for a constant time and, thereafter, the value of the command pressure is raised up to the target value when a shift range of the continuously variable transmission is switched from a neutral range to a running range, the command pressure being raised at a rate lower than a step input to suppress an overshoot developed in the actual line pressure.
Abstract:
A lock-up control device controls a lock-up clutch in a torque converter. The lock-up clutch is engaged by supplying a lock-up control pressure. The torque converter transmits torque via oil in a torque converter chamber when the lock-up clutch is disengaged, and transmits torque directly when the lock-up clutch is engaged. In the lock-up state, the oil pressure in the torque converter chamber is decreased by discharging oil in the torque converter chamber. By providing a circuit which leads oil discharged from the torque converter chamber to a lubricating part of the transmission, the balance between the inflowing oil amount and outflowing oil amount is improved, and oil insufficiency is prevented.
Abstract:
A belt-type continuously variable transmission having a forward clutch is incorporated with a speed-changing hydraulic pressure control system. The control system includes an engaging pressure regulating device for outputting an engaging pressure for the forward clutch. An electronically controlled hydraulic pressure control valve is provided to output a signal pressure which is able to cause the engaging pressure regulating device to set the engaging pressure. A control unit is provided to output a control command signal to the hydraulic pressure control valve, the control command signal causing the hydraulic pressure control valve to output the signal pressure. Here, the engaging pressure regulating device is arranged to output a minimum value of the engaging pressure in response to a maximum value of the signal pressure from the hydraulic pressure control valve, and to output a maximum value of the engaging pressure in response to a minimum value of the signal pressure.
Abstract:
A hydraulic control apparatus for an automatic transmission with a line pressure regulator valve operative to regulate an oil pressure produced by an oil pump and set a line pressure, the hydraulic control apparatus including a control unit outputting a first command for controlling the line pressure regulator valve to set the line pressure to a minimum value immediately after engine start, and a second command for controlling the line pressure regulator valve to set the line pressure to a target value in accordance with increase in engine speed. The control unit is programmed to set the target value of the line pressure to a value smaller than a maximum value of the line pressure and/or reduce a target speed of engine speed, upon start of the engine in a low temperature condition.