| 摘要 |
PURPOSE:To reduce an engaging shock in time of shifting down, by setting up an electric circuit device which controls two hydraulic circuit valve select devices in time of down shift discrimination and generates a neutral interval as long as being proportionate to a car speed. CONSTITUTION:When a select valve 33 is situated in a D position and a driving state consists in a third-speed setting range by way of example, both solenoid valve S1 and S2 are turned to OFF and both spools 35 and 37 of 1-2 and 2-3 shift valves 34 and 36 are situated downward whereby clutches C1 and C2 are engaged with each other, thus a third-speed step is formed up. Under this condition, when the driving state enters a second-speed setting range, an electronic control device 60 performs its down shift discrimination. That is to say, the control device 60 calculates a proper neutral interval in conformity with the output of a car speed sensor 70, and turning these solenoid valves S1 and S2 to ON as long as the duration. With this constitution, a neutral step is formed up. After the elapse of the specified period of time, the solenoid valve S1 is turned to OFF, and a brake B1 is engaged whereby a second-speed step is formed up. |
