| 摘要 |
PURPOSE:To reduce shock of gear shift by providing a low oil pressure corresponding to the operating condition for the short period of gear shift when it is detected that relative rotation of a pair of friction elements comes to a stop. CONSTITUTION:An orifice 426, oil pressure control valve 250 and a solenoid valve 320 jointly constitute an electric oil pressure converting unit 340 which generates a controlled oil pressure corresponding to the operating condition at the time of gear shift in an oil passage 422 due to the function of the same valve 320. The solenoid valve 320 controls the time of opening and closing of an orifice 321 according to the operating condition and thus controls the oil pressure P1 acting on the pressure retaining face 251 of the oil pressure control valve 250. As a result, a low oil pressure corresponding to the operating condition is generated in the oil passage 422 by means of the oil pressure control valve 250. The time to start operation and operating period of the solenoid valve 320 are determined by signals issued by the gear shift detector unit and the coupling time detector unit, etc. |
