Automatic fluid pressure-intensifying apparatus and method of a

Abstract

Disclosed is automatic fluid pressure-intensifying apparatus and method of a hydraulic traveling device for increasing a traveling capability or a pulling capability of a heavy equipment by changing a relief pressure in a hydraulic circuit under the state that a working device of the heavy equipment does not operate and a traveling device only operates. In the automatic fluid pressure-intensifying apparatus of the hydraulic traveling device, a first control valve selectively changes a flow direction of a hydraulic fluid being supplied by a hydraulic pump toward a traveling motor of the heavy equipment. Further, a second control valve selectively changes the flow direction of the hydraulic fluid being supplied by the hydraulic pump toward a working device of the heavy equipment. A relief valve restricts an allowable maximum pressure in a hydraulic circuit. A first pressure switch detects a pressure in a first pilot line of the first control valve, and a second pressure switch detects a pressure in a second pilot line of the second control valve. A controller judges whether the controller will intensify the allowable maximum pressure in the hydraulic circuit or not by receiving signals generated from the first pressure switch and the second pressure switch. A solenoid valve changes an allowable maximum pressure of the relief valve into a pressure corresponding to a signal generated by the controller.