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:
May. 05, 2015
Filed:
Mar. 30, 2009
Teruo Akiyama, Kokubunji, JP;
Hisashi Asada, Yokohama, JP;
Jin Kitajima, Yokohama, JP;
Kazuhiro Maruta, Kawaguchi, JP;
Takeshi Ooi, Oisi-machi, JP;
Masashi Ichihara, Hiratsuka, JP;
Teruo Akiyama, Kokubunji, JP;
Hisashi Asada, Yokohama, JP;
Jin Kitajima, Yokohama, JP;
Kazuhiro Maruta, Kawaguchi, JP;
Takeshi Ooi, Oisi-machi, JP;
Masashi Ichihara, Hiratsuka, JP;
Komatsu Ltd., Tokyo, JP;
Abstract
The system includes: a variable displacement hydraulic pump supplying pressure oil to a hydraulic actuator; a pressure detector detecting a pump discharge pressure from the hydraulic pump; a control valve controlling a supply of the pressure oil to the hydraulic actuator; a controller controlling a pump displacement of the hydraulic pump; a hydraulic motor rotating an upper structure of the construction machine; a swing relief valve defining a relief pressure of the hydraulic motor; and a control lever switching a control valve for the hydraulic motor. The controller includes: an adjuster that, when a pump discharge pressure detected by the pressure detector exceeds a first set value, conducts an adjustment to reduce the pump displacement; and a canceller that cancels the adjustment when the pump discharge pressure falls below a second set value. The second set value is equal to or larger than the first set value.