| 摘要 |
PURPOSE:To provide an excellent speed change action in an automatic transmission wherein line pressure is raised at the time of a shift-up speed change by raising the line pressure in correspondence with inertial torque discharged at a speed change stage prior to the shift-up speed change. CONSTITUTION:In an automatic transmission 1 provided with a torque converter 10, a main transmission 20 and an auxiliary transmission 30, a desired speed change stage is obtained by selective engagement among an advance clutch 23, a direct coupled clutch 24, a 3-4 brake and a low reverse brake 26 in the main transmission 20. In the auxiliary transmission 30, a low speed stage and a high speed stage are switched with each other by connection/disconnection of a direct coupled clutch 32. Engagement pressure to each friction component is controlled by an oil pressure control device. In the oil pressure control device, line pressure is raised, at the time of a shift-up speed change, in correspondence with inertial torque at this speed change, and also the line pressure is raised in correspondence with inertial torque at a speed change stage prior to the shift-up speed change. |
