APPARATUS FOR CONTROLLING THE FLOW RATES OF THE HYDRAULIC PUMP OF A WHEEL LOADER

摘要

A flow rate control device for a hydraulic pump of a wheel loader is provided to prevent the surging phenomenon of discharge pressure of a variable capacity hydraulic pump by preventing the sudden increase of rod sensing pressure by discharging rod sensing pressure to a tank while a boom control spool is not under boom pilot pressure. The invention relates to a flow rate control device for a hydraulic pump of a wheel loader for preventing the surging phenomenon of discharge pressure of a variable capacity hydraulic pump by reducing discharge pressure of a variable capacity hydraulic pump(P1) by dropping boom cylinder rod sensing pressure rapidly by opening an auxiliary discharge line(42) and discharging hydraulic pressure of a boom cylinder rod sensing line(30A) to a return line(22) if boom pilot signal pressure is below than the appointed level and discharging, and reducing the rod sensing pressure of the boom cylinder rod sensing line gradually by closing the auxiliary discharge line if the boom pilot signal pressure detected from a secondary shuttle valve(44) is above the appointed level.