| 摘要 |
<p>A hydraulic servo mechanism for vehicular transmissions, having a hydraulic servo consisting of a cylinder, and a piston fitted in the cylinder and provided with a means for energizing the piston so as to return the same to its original position; a change-over valve for switching the communication between a hydraulic pressure source and the hydraulic servo to that between a drain oil passage and the hydraulic servo, and vice versa; and an accumulator disposed between the hydraulic servo and change-over valve and consisting of a cylinder, and a piston fitted in the cylinder and provided with a means for energizing the piston so as to return the same to its original position, a frictional engaging element of an automatic vehicular transmission is engaged and disengaged in accordance with the operation of the change-over valve, characterized in that the discharge resistance of a working oil from the accumulator, the discharge resistance of a working oil from the hydraulic servo, the accumulator-returning force and the hydraulic servo-returning force are regulated to set the servo mechanism so that the hydraulic pressure in the hydraulic servo becomes lower than that in the accumulator when the hydraulic servo and accumulator are communicated with the drain oil passage for the purpose of disengaging the frictional engaging element.</p> |
