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:
Jul. 29, 2025
Filed:
Mar. 30, 2023
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Teruki Igarashi, Tsuchiura, JP;
Hiroaki Tanaka, Tsuchiura, JP;
Ryohei Fukuchi, Tsuchiura, JP;
Yusuke Suzuki, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A work machine includes a flow control valve that controls the flow rate of a hydraulic operating fluid supplied from a hydraulic pump to a hydraulic cylinder, a solenoid valve that generates an operation pressure for operating the flow control valve, and a controller. The controller executes learning processing of changing in a stepwise manner the operation pressure generated by the solenoid valve, sensing the pressure of the hydraulic cylinder, and storing the operation pressure when the pressure of the hydraulic cylinder has become a reference value, as a learning result operation pressure. The controller calculates a differential pressure across the flow control valve and computes a target opening area of the flow control valve on the basis of the differential pressure across the flow control valve and a target flow rate of the hydraulic operating fluid that passes through the flow control valve. The controller computes a target value of the operation pressure generated by the solenoid valve, on the basis of an opening characteristic table, the target opening area, and the learning result operation pressure, and controls the solenoid valve on the basis of the target value of the operation pressure.