METHOD AND APPARATUS FOR CONTROLLING HYDRAULIC PUMP FOR WORKING MACHINE OF WORKING VEHICLE

摘要

A hydraulic pump displacement control apparatus for a working vehicle, the apparatus being capable of reliably detecting the vehicle being engaged in excavation work and reducing loss in power. The control device has a bottom pressure detector (45) for detecting an oil pressure in a bottom side (13A) of a cylinder (60) for actuating a working machine (10), a displacement control device (41) for controlling the displacement of a variable displacement hydraulic pump (26), and a controller (50) for outputting a displacement control signal to the displacement control device in order to reduce the displacement of the hydraulic pump to a predetermined displacement that is smaller than the maximum displacement, the signal output being made when the controller determines that excavation work has started at a time when a predetermined time has passed with a detection value from the bottom pressure detector being less than a predetermined value, and, after that, the detection valve exceeds the predetermined vale.