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:
Aug. 27, 2013
Filed:
Mar. 09, 2010
Naoki Hagiwara, Tsuchiura, JP;
Tsuyoshi Nakamura, Tsuchiura, JP;
Kensuke Sato, Tsuchiura, JP;
Yasuo Okano, Tsuchiura, JP;
Kouji Ishikawa, Tsuchiura, JP;
Mitsuhiko Kanehama, Tsuchiura, JP;
Hiroyuki Azuma, Tsuchiura, JP;
Naoki Hagiwara, Tsuchiura, JP;
Tsuyoshi Nakamura, Tsuchiura, JP;
Kensuke Sato, Tsuchiura, JP;
Yasuo Okano, Tsuchiura, JP;
Kouji Ishikawa, Tsuchiura, JP;
Mitsuhiko Kanehama, Tsuchiura, JP;
Hiroyuki Azuma, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
Disclosed is a hydraulic drive system for a working machine, which enables to conduct forced regeneration continuously for a sufficient time. Based on an input of a lock detection signal Sfrom a gate lock detection switcha controllerdetects that a gate lock leverfor controlling a gate lock on/off valveis in a locked state, in other words, hydraulic actuators such as an arm cylinderarranged on a hydraulic excavatorare all in non-operated states. Upon an input of a forced regeneration command signal So from a forced regeneration switchin this detected state, control signals Cp,Cf are outputted to a boosting control valveand regulatorto make a forced regeneration means (an arm cylinder control valveand the regulator) conduct forced regeneration.