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. 12, 2021
Filed:
Apr. 06, 2018
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Juri Shimizu, Hitachinaka, JP;
Kenji Hiraku, Kasumigaura, JP;
Hiromasa Takahashi, Abiko, JP;
Shohei Sugiki, Kasumigaura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
Provided is a work machine that can selectively establish a closed circuit connection between a single rod-type hydraulic cylinder and a plurality of bidirectional-type hydraulic pumps, the work machine being capable of enhancing responsiveness of the single rod-type hydraulic cylinder when a high-speed lever switching operation is conducted in a state in which a rod pressure of the single rod-type hydraulic cylinder is higher than a bottom pressure. When a bucket lever () is operated to a side of extending the bucket cylinder in a state in which a pressure in a rod chamber () of the bucket cylinder () is higher than a pressure in a bottom chamber (), a controller () opens a rod-side proportional valve () and discharges a working fluid in the rod chamber to a working fluid tank () such that a differential pressure between the pressure in the rod chamber and the pressure in the bottom chamber is reduced below a switching pressure (Psw) of a flushing valve ().