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:
Oct. 23, 2018
Filed:
Apr. 21, 2014
Hitachi Construction Machinery Tierra Co., Ltd., Koka-shi, Shiga, JP;
Kiwamu Takahashi, Koka, JP;
Yasutaka Tsuruga, Ryugasaki, JP;
Yoshifumi Takebayashi, Koka, JP;
Kazushige Mori, Koka, JP;
Natsuki Nakamura, Koka, JP;
Hitachi Construction Machinery Tierra Co., Ltd., Koka-shi, JP;
Abstract
To cope with a variety of flow rate balance required of two actuators flexibly in combined operations driving two actuators of high maximum demanded flow rates at the same time while suppressing the wasteful energy consumption caused by the throttle pressure loss in a pressure compensating valve, the arrangement is such that when the demanded flow rate of a boom cylinderis lower than a prescribed flow rate, the boom cylinderis driven only by hydraulic fluid delivered from a single flow type main pumpand when the demanded flow rate of the boom cylinderis higher than the prescribed flow rate, the hydraulic fluid delivered from the single flow type main pumpand hydraulic fluid delivered from a first delivery portof a split flow type main pumpare merged together and the boom cylinderis driven by the merged fluids. Further, when the demanded flow rate of an arm cylinderis lower than a prescribed flow rate, the arm cylinderis driven only by hydraulic fluid delivered from a second delivery portof the split flow type main pumpand when the demanded flow rate of the arm cylinderis higher than the prescribed flow rate, hydraulic fluid delivered from the first delivery portand hydraulic fluid delivered from the second delivery portare merged together and the arm cylinderis driven by the merged fluids.