Fluid pressure control system for automatic power transmission

摘要

A fluid pressure control system for automatic power transmissions including a source of fluid providing a controlled line pressure, a manual valve movable to a number of positions including range P (parking), range R (reverse), range N (neutral), range "3", range "2" and range "1" in the order mentioned for setting the transmission in a desired operational range and provided with at least three spaced lands. A unitary, first pressure regulator valve is provided which has at least two spaced valve lands and a fluid passage interconnecting the unitary, first pressure regulator valve and the manual valve. The fluid passage communicates with a fluid chamber provided between the valve lands of the unitary first pressure regulator valve. In the range P, one of the valve lands of the manual valve is adapted to cut the line pressure. In the range R, the aforementioned fluid passage is blocked by another of the valve lands of the manual valve. The fluid passage communicates with a fluid chamber provided between valve lands of the manual valve in the ranges of N, D, "3", "2" and "1".