| 摘要 |
PURPOSE:To suppress the generation of shift shock by temporarily switching to low torque valve operating characteristic to start shifting when power-on and shift-up are conducted during operation with high torque valve operating characteristic. CONSTITUTION:When power-on and shift-up of an automatic transmission AT is conducted during operation of an engine E by using high torque valve characteristic by a variable timing lift mechanism, a control unit CU first switches the valve operating characteristic of intake and exhaust valves to low torque valve operating characteristic and, after delay of a determined time, operates the shift solenoids 251-253 of a hydraulic control valve CV to start the power-on and shift-up speed change. When the shift is completed, the valve operating characteristic is returned to high torque valve operating characteristic. Hence, the change quantity of the transmission output is reduced even if the changing rate at the time of shifting is unchanged, and the generation of shift shock can be suppressed by this extent. |
