Line pressure controller for automatic transmission and method thereof

Abstract

The invention provides a hydraulic pressure control system for an automatic transmission and a method that enable a smooth kick-down from any accelerator (throttle) opening degree. The hydraulic pressure control system comprises at least a throttle opening degree sensor (3), a vehicle speed sensor to detect a vehicle speed, a hydraulic (or oil) pressure controller (including device) (6) which receives signals (S3A, S3B, S4A, S4B) from sensors (3, 4), and a line pressure solenoid (14) which receives a signal (S9) from the hydraulic pressure controller (6). The hydraulic pressure controller (6) further comprises a throttle opening memory storage (including device) (8) for storing the signal S3B from the throttle opening degree sensor (3) and a line pressure controller (including device) to control a line pressure in shifting according to the throttle opening degree, stored by the throttle opening memory storage, before a predetermined period from a shift gear determination point. The system controls the line pressure in shifting according to the throttle opening degree before a predetermined period from a shift gear determination point and enables a smooth clutch engagement despite various throttle opening degrees before the shift gear determination point.

Dependencies are inferred from the claim text.