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. 06, 2024
Filed:
Dec. 12, 2019
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Kohei Ogura, Tsuchiura, JP;
Katsuaki Kodaka, Tsukuba, JP;
Masahiro Kayane, Tsuchiura, JP;
Yoshihiro Shirakawa, Tsukuba, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A hydraulic excavator is provided which can suppress the fuel consumption amount and improve the work efficiency by reducing the hydraulic pressure loss generated when a plurality of hydraulic actuators different in load are operated simultaneously. The hydraulic excavator includes a center bypass flow control valve that is arranged at the most downstream of a center bypass line and limits the flow rate of hydraulic fluid passing through the center bypass line in response to the operation amount of the second operation device in a case where a second operation device is operated, and a spool stroke limitation device that, in a case where a first operation device and the second operation device are operated simultaneously, limits the spool stroke amount of a second directional control valve in response to the operation amount of the first operation device in a state in which the spool stroke amount of a third directional control valve is controlled in response to the operation amount of the second operation device.