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:
Jan. 13, 2026
Filed:
Mar. 11, 2022
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Ryohei Fukuchi, Tsukuba, JP;
Katsuaki Kodaka, Tsukuba, JP;
Mitsuhiko Kanehama, Kasumigaura, JP;
Teruki Igarashi, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A work machine includes: a first pump and a second pump that are driven by an engine; a hydraulic actuator driven by a hydraulic working fluid supplied from the first pump; a control valve that controls a flow of the hydraulic working fluid supplied to the hydraulic actuator; a solenoid valve that reduces a pressure of the second pump to generate a pilot pressure for operating the control valve; a controller that controls the solenoid valve; an engine operating section that enables operation for activating the engine; and a rotation speed sensor that senses a rotation speed of the engine. The controller applies a drive current to the solenoid valve to drive the solenoid valve when a current application condition is established, the current application condition including that it is assessed, on the basis of a sensing result of the rotation speed sensor, that the engine is in a stopped state, and including that ON operation of the engine operating section is performed in a state where activation operation is not performed by the engine operating section.