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. 25, 2022
Filed:
Mar. 19, 2018
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
To provide a construction machine that can improve the energy efficiency in a leveling operation in which an arm crowding operation and a boom raising operation are performed simultaneously. A controller () controls a first regulator () according to the maximum value among target displacement volume (Qa) of a first hydraulic pump () that is based on a boom raising operation amount (Pi), and target displacement volume (Qa) of the first hydraulic pump () that is based on an arm crowding operation amount (Pi) of an arm operation device () if the boom raising operation amount (Pi) of a boom operation device () is smaller than a predetermined operation amount, or if a delivery pressure (P) of a second hydraulic pump () is equal to or higher than a predetermined pressure, and controls the first regulator () according only to the target displacement volume (Qa) of the first hydraulic pump () that is based on the boom raising operation amount (Pi) if the boom raising operation amount (Pi) is equal to or larger than the predetermined operation amount, and the delivery pressure (P) of the second hydraulic pump () is lower than the predetermined pressure.