| 摘要 |
PROBLEM TO BE SOLVED: To prevent a transmission from producing shock and an engine from blowing revolution up by applying engagement hydraulic pressure at proper timing even if a rising speed of input rotational frequency is different from when power-on down shift (performing down shift when throttle opening is opened at certain degree) is performed. SOLUTION: This method comprises step of asking for time rate of change of turbine rotational frequency in the middle time of variable speed when down shift is performed in power-on condition and step of presuming time until a turbine reaches rotational frequency at low-speed stage from the turbine rotational frequency and its time rate of change. The method also comprises step of determining output timing of the engagement hydraulic pressure so that the presumed time and response time of engagement hydraulic pressure of engagement side engaging element approximate and step of outputting the engagement hydraulic pressure on the engagement side engaging element in this timing. Therefore, the method is capable of raising hydraulic pressure of the engagement side engaging element as high as hydraulic pressure of engagement completion condition immediately when the turbine rotational frequency reaches rotational frequency at low-speed stage and can improve shock. COPYRIGHT: (C)2006,JPO&NCIPI |
