| 摘要 |
<p>PURPOSE:To obtain a pressure rising characteristic which is suitable to condition of speed change, by setting a switching means adapted to increase capacity of an accumulator mechanism set in series with a pressure regulating mechanism, as the travelling speed change position is shifted to the lower speed side. CONSTITUTION:A selector valve 25 for an accumulator mechanism can be switched between on-condition, in which pressure oil is fed to the second accumulator 24 when a three position selector valve S3 for an auxiliary gear transmission is positioned at the low-speed position L, and off-condition, in which the second accumulator 24 is connected to a tank T when the three position selector valve S3 for the auxiliary gear transmission is positioned at the medium-speed position and the high-speed position H. Accordingly, capacity of an accumulator mechanism 26 which consists of the first accumulator 23 and the second accumulator 24, can be increased in the low-speed condition, by automatically switching the feed of pressure oil to the second accumulator 24, according to the travelling speed change condition. Therefore, a pressure rising characteristic which is suitable to a condition of speed change, can be attained.</p> |
