摘要 |
An automatic transmission for a four wheel drive automotive vehicle comprising a torque converter, an automatic transmission connected to a turbine shaft of the torque converter for transmitting the output of the engine to the front-wheel, a fluid operated clutch for transmitting the output to the rear-wheel, and a pressure oil control for operating the automatic transmission. The pressure oil control includes a pressure regulator valve to produce a line pressure according to the operational condition of the engine and a valve for the clutch. The pressure oil control means is so arranged that the line pressure is raised with increase of load of the engine, and the valve is adapted to operate the clutch by the raised line pressure, such that the automatic transmission is automatically changed to the four wheel drive in accordance with the driving condition. |