VALVE ARRANGEMENT FOR THE HYDRAULIC CIRCUIT OF A WORK MACHINE

摘要

The present disclosure relates to a valve arrangement (60) for a boom control system (30) or for other control systems for work machine (10) components that may be lowered under gravity. The problem addressed is the prevention of the boom (13) or other work machine (10) component from dropping uncontrollably under a hose burst condition. The disclosure provides a valve arrangement (60) for a hydraulic system (30) for raising and lowering a component of a work machine (10). The valve arrangement (60) comprises an inlet (61) and an outlet (62). A pilot operated load control valve (63) is fluidly connected between the inlet (61) and the outlet (62), the load control valve (63) having an energised unidirectional state allowing hydraulic fluid to pass from the outlet (62) to the inlet (61) and a de-energised unidirectional state allowing hydraulic fluid to pass from the inlet (61) to the outlet (62). A pilot conduit (65) is configured to direct pilot hydraulic fluid to actuate the load control valve (63). A connecting conduit (67) fluidly connects the pilot conduit (65) to the inlet (61), the connecting conduit (67) comprising a flow restriction (68) and a check valve (69) configured to allow hydraulic fluid to flow only in a direction from the pilot conduit (65) towards the inlet (61).