The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 11, 2025
Filed:
Aug. 07, 2020
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A hydraulic excavatorincludes an engine, a main hydraulic pumpdriven by the engine, a plurality of hydraulic actuators driven with pressure oil discharged from the main hydraulic pump, a plurality of flow rate control valves adapted to control the flow rate of pressure oil to be supplied from the main hydraulic pumpto the respective hydraulic actuators, a pilot hydraulic pumpadapted to supply pressure oil for driving the flow rate control valves, and a controllerconfigured to control the discharge flow rate of the pilot hydraulic pump. The controllercontrols the discharge flow rate of the pilot hydraulic pumpsuch that it becomes equal to the sum of requested pilot flow rates determined in accordance with control commands for the respective flow rate control valves and a preset standby flow rate.