AUTOMATIC TRANSMISSION FOR FOUR WHEEL DRIVE AUTOMOTIVE VEHICLES

摘要

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