Patent ID: 6277049
Filing Date: 2001-08-21
Classification: F16H,Y10T

Abstract:
A shift control system of an automatic transmission executing a shift from a first speed position to a second speed position, the automatic transmission having an automatic shift mode and a manual shift mode, the shift control system comprising:a first friction element engaged so as to put engine brake active when the first speed position is selected in the manual shift mode, the first friction element being engaged by a pressure of hydraulic oil;a one-way clutch engaged when the first position is selected in the automatic shift mode;a second friction element engaged when the second speed position is selected in one of the manual shift mode and the automatic shift mode, the second friction element being engaged by a pressure of hydraulic oil;a first solenoid varying the pressure of hydraulic oil applied to the first friction element according to a first signal;a second solenoid varying the pressure of the hydraulic oil applied to the second friction element according to a second signal;a controller outputting the first signal to said first solenoid to decrease the pressure of hydraulic oil and outputting the second signal to said second solenoid to engage the second friction element when the shift from the first shift position to the second shift position is executed in the manual shift mode; andan oil temperature sensor detecting a temperature of the hydraulic oil and outputting a temperature signal indicative of the temperature of the hydraulic oil;wherein said controller delaying the output of the second signal as compared with the output of the first signal when the temperature signal from said oil temperature sensor is lower than a predetermined temperature.