| 摘要 |
<p>PURPOSE:To prevent shift shock by arranging means for controlling the transmission capacity of frictional engaging element from zero to predetermined level in accordance to the fluid pressure between the frictional engaging element of automatic speed change element and hydraulic source and enabling quick transfer to creep preventing state when performing shift operation. CONSTITUTION:In a device where first speed gear series is established through coupling of first speed clutch C1 while second, third or fourth speed gear series is established through further coupling of second, third or fourth speed clutches C2-C4 under clutching of first speed clutch C1, a creep prevention valve 50 is placed in the way of pressure oil feed path 41 to the hydraulic operating section of first speed clutch C1. While a solenoid valve 70 having a valve body 71 for opening/closing the port 63a of seat 63 of said valve 50 is arranged at the seat 63 side end of creep prevention valve 50. Opening/closing of said solenoid valve 70 is controlled through drive circuit 102 in accordance with the outputs from brake detector 100 and engine rotation detector 101.</p> |
