| 摘要 |
PROBLEM TO BE SOLVED: To accurately perform precharge control to fill working fluid into a friction engagement element so as to move a piston to a position where engagement of the friction engagement element on the engagement side of an automatic transmission starts. SOLUTION: In the case where the temperature of the working fluid is a predetermined value or lower, at a time t1 when hydraulic pressure inside a hydraulic circuit of a brake B2 (friction engagement element on the engagement side) is raised to predetermined pressure and an output signal of a hydraulic switch for the brake B2 is switched from an off state to an on state after a hydraulic command value of the brake B2 is set to be predetermined precharge hydraulic pressure to start precharge control, passing time from start of the precharge control of the brake B2 until the hydraulic pressure inside the hydraulic circuit of the brake B2 is raised to the predetermined pressure is calculated as pressure increase time Ta. In accordance with the pressure increase time Ta (information reflecting flow characteristics etc. of working fluid inside the hydraulic circuit of the brake B2), execution time Tb of the precharge control of the brake B2 is calculated to set completion timing of the precharge control of the brake B2. COPYRIGHT: (C)2009,JPO&INPIT |
