| 摘要 |
PURPOSE:To secure the speedy speed change responsiveness by installing a low speed stage pressure adjusting valve which can perform sequence action into a subspeed change mechanism and suspending said sequence action in the small throttle opening state in case of engine brake. CONSTITUTION:When a subspeed change mechanism is shifted in 4-3, the spool 102 of a shift valve 100 is moved downward by a solenoid 118, and an oil passage 110 is drained, and the oil pressure in a high speed stage side frictional element 32 is gradually lowered through an orifice 124 and an accumulator 128. When a piston 136 is set at the lowest position, the oil pressure in an oil passage 126 sharply lowers, and the second spool 147 of a low speed stage pressure adjusting valve 132 lowers, and the first spool 146 is put into a pressure adjusted state by the line pressure in an oil passage 112, and the oil pressure is supplied into a low speed stage side frictional element 33. If a small throttle opening degree is realized, when engine brake is to be applied, the third range pressure is supplied from an oil passage 190, and the second spool 140 is immediately lowered. Thus, the speedy speed change responsiveness can be obtained in the engine brake. |
