| 摘要 |
PROBLEM TO BE SOLVED: To provide a simplified electronic control automatic transmission in which a shift point can be freely changed while almost all hydraulic circuits of the hydraulic control automatic transmission are being utilized as they are. SOLUTION: The automatic transmission is provided with a regulator valve 11 for outputting a line pressure and a plurality of shift valves 14 to 16 for selectively supplying the line pressure to a frictional element, wherein these shift valves are changed over for making a plurality of shift stages. A predetermined first signal pressure P1 not responding to a degree of opening of a throttle and a vehicle speed is inputted to one end side of each of shift valves 14 to 16 and a second signal pressure P2 is inputted from a solenoid valve 17 to the other end of each of shift valves. An electronic control device 50 determines the shift stage in response to sensing signals of at least a vehicle speed sensor and a throttle opening degree sensor and outputs a control signal to the solenoid valve 17 so that the second signal pressure P2 varying in a stepwise manner in response to the determined shift stage is generated. |
