DIFFERENTIAL PRESSURE POWER ROAD SPEED CONTROL SYSTEM

摘要

DIFFERENTIAL PRESSURE POWER ROAD SPEED CONTROL SYSTEM A vehicle road speed control system in which the engine intake manifold pressure and the engine exhaust manifold pressure are utilized on opposite sides of a servomotor power wall to control the engine throttle and maintain a desired constant vehicle speed. The intake manifold pressure is normally subatmospheric and the exhaust manifold pressure is normally superatmospheric. Within the usual operating range of vehicle engine loads, the pressure difference between the two pressures remains substantially constant and provides a more uniform pressure differential than that provided in systems in which atmospheric pressure is the higher of the two pressures. The intake manifold pressure has a control valve in the conduit leading to the servomotor which varies the value of the pressure difference delivered to the servomotor in accordance with a control signal generated by a comparison of desired vehicle speed and actual vehicle speed.