| 摘要 |
PURPOSE:To prevent the delay in response to switching to the first change step and to suitably control the rising of the engaging pressure at the time of switching to the second speed change step in an automatic transmission including a friction element engaged at plural speed change steps, especially the friction element which is put in the engaging state at the first speed change step where speedy engagement is required and at the second speed change step where the delayed connection is required. CONSTITUTION:A control valve 76 is provided in engaging pressure supply paths 115, 116 to a direct-coupled clutch 23 put in the engaging state at 4-speed (direct-coupling step of main transmission) and at a backward speed. At the time of changing the speed to 4-speed, the rising of the engaging pressure is controlled according to the control pressure feedbacked through an orifice 83a and an accumulator 91 by the control valve 76. On the other hand, at the time of switching to the backward step, the line pressure is supplied to one end port 76b of the control valve 76 to check the pressure regulating operation of the control valve. |
