| 摘要 |
PURPOSE:To reduce the occurrence of a transmission shock, by a method wherein, when the oil pressure of a friction fastening element is increased, during the initial stage, it is increased with the lapse of a time, and after an oil pressure is held at a specified value for a given time, the oil pressure is increased to a highest value. CONSTITUTION:When an oil pressure is started to be fed in an oil passage 12, a piston 16 starts a stroke, an up force produced by an oil pressure exerted on an oil chamber 20 and a spring 18 is balanced with a down force exerted by means of the oil pressure of an oil chamber 22. When the piston 16 effects a further stroke, the spring 18 is stretched to its full capacity and is brought into a state in which no force is exerted on the piston 16, and thereafter, a working pressure is held at a specified oil pressure. When the piston 16 performs a stroke to an uppermost position, the working pressure is rapidly increased to the highest pressure of an oil pressure source. This constitution reduces the peak value of a torque fluctuation prevailing during completion of an inertia phase and improves transmission feeling during shifting of a gear. |
