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:
Jun. 06, 2023
Filed:
Sep. 14, 2020
Hitachi Construction Machinery Tierra Co., Ltd., Koka, JP;
Yuichi Ogawa, Koka, JP;
Takeshi Ishii, Hino-cho, JP;
Seiichi Kihara, Koka, JP;
Kiwamu Takahashi, Moriyama, JP;
Abstract
To reduce an increase in the electric power consumption of an electric motor according to the state of an electric power source at the start of driving of an actuator, and make it possible to use devices in an appropriate state in an electrically driven hydraulic construction machine including a driving system that drives a hydraulic pump by using the electric motor. For this purpose, a controllersets a target relief pressure of a relief valveto a normal relief pressure Pn (first relief pressure) when an operation lever deviceis not being operated and a storage amount SOC(t) of a battery(the state quantity of an electric power source) is equal to or larger than a threshold S, and sets the target relief pressure to a reduced relief pressure Pr(t) (second relief pressure) lower than the normal relief pressure Pn (first relief pressure) when the operation lever deviceis not being operated, and the storage amount SOC(t) of the battery(the state quantity of the electric power source) is smaller than the threshold S