Control system for power train and auxiliary equipment driven from a common prime mover

摘要

A control system for an engine driven power train having a variable torque absorption transmission mechanism typically including a torque converter, in conjunction with a hydraulic control circuit for the implement of an excavating-loading vehicle such as a loader. The control circuit comprises lift and tilt cylinder means connected via respective control valves to a pump driven by the vehicle engine. The pump also communicates with the transmission mechanism via a variable pressure regulator valve which functions to condition the transmission mechanism for a relatively high torque absorption characteristic during vehicle propelling operation so that engine torque may be efficiently transmitted to the drive wheels of the vehicle. When either of the control valves is actuated for raising or tilting back the bucket of the loader, the transmission mechanism is automatically conditioned for a relatively low torque absorption characteristic so that the pump may be driven without any substantial decrease in engine speed.