FLUID POWER SYSTEMS ON HYDRAULIC EXCAVATORS

Abstract

CLSS (Closed-Center-type Load Sensing Systems) for fluid power controls in hydraulic excavators are capable of controlling complex motions of multiple actuators with high accuracy against varying loads under varying engine speed conditions, with expectations for improved controllability and compatibility of hydraulic excavators to many kinds of works in which attachments are used. Conversely, operators have made the best use of the characteristics of conventional fluid power systems, in which each actuator speed is varied by inertia or engine speed change.
Accordingly in 1993, a range of new hydraulic excavators were introduced, equipped with newly developed CLSS's, which are suitable for either traditional excavator use or new electrical operation, including automatic electronic control by microcomputer.