| 摘要 |
PURPOSE: To reduce shock upon re-engagement of frictional engagement elements to occur when a hydraulic oil temperature is very high or very low after automatic engine shutdown, or when no pump is available, without an increase in motor-driven oil pump dimensions. CONSTITUTION: When the hydraulic oil temperature (AT oil temperature) satisfies TMIN≤AT oil temperature≤TMAX, a motor-driven oil pump is actuated upon automatic engine shutdown for the oil pressure in an oil pressure controller to be kept at the prescribed level PX for the prevention of shock to follow the re-engagement of frictional engagement elements. When the AT oil temperature < TMIN or >TMAX, the oil pump is not actuated upon automatic engine shutdown but a mechanical pump is actuated motored by a motor generator (M/G) for the oil pressure to be kept at the level PX or higher (PZ). Thus, the above constitution dispenses with the need of enlarging motor-driven oil pump dimensions now that the oil pump does not work. |
