| 摘要 |
PURPOSE:To obtain a proper oil pressure characteristic for both up-shift and down-shift by providing an orifice which generates a throttling effect only when oil pressure is discharged out of an accumulator on an oil passage connected to the accumulator. CONSTITUTION:A one-way orifice 110 has no throttling effect when oil flows into an accumulator oil passage 108, hence, without totally acting at the time of up-shift speed change. On the other hand, the throttling effect of the one-way orifice 110 is produced at the time of down-shift speed change. Thereby, oil pressure on both first frictional element H/C and second frictional element B/B sides can be rapidly discharged. This is because the oil which is discharged out of the accumulator is subjected to the throttling effect of the one-way orifice 110 without immediately acting on the first and second frictional element sides. When the oil pressures in the first and second frictional elements are lowered, these are kept nearly in a constant oil pressure of the oil which is returned from the accumulator through the one-way orifice 110. Thereby, the time up to the start of a down-shift speed change can be reduced. |
