| 摘要 |
PURPOSE:To decrease the rapid increase of a servo-hydraulic pressure and provide a smooth control over a speed transmission in the hydraulic servo device for use in an automatic transmission of an automobile by a method wherein an air ventilation hole not causing oil to be flowed therethrough is made at an end wall of a hydraulic chamber and an air reservoir is formed in the hydraulic chamber. CONSTITUTION:When the hydraulic oil is flowed into a release hydraulic chamger B, at first the oil is apt to flow out from the clearance S as the surface of the hydraulic oil is raised. The oil is hardly flowed out due to high viscosity of the oil if the clearance shows a space having a value of 15mu to 25mu. Further, when the surface of the hydraulic oil is raised, the ball 17 is moved up to close the air ventilation hole 16a. Lastly, when the air ventilation hole 16a of the upper plug 16 is closed, the upper portion in the hydraulic chamber B becomes a closed space, so that the air in the space of the upper portion may act as an accumulator to decrease an increasing speed of the hydraulic pressure. |
