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:
Sep. 18, 2012
Filed:
Aug. 27, 2004
Yoichi Kowatari, Ibaraki, JP;
Yasushi Arai, Ibaraki, JP;
Kouji Ishikawa, Ibaraki, JP;
Kazunori Nakamura, Ibaraki, JP;
Nobuei Ariga, Ibaraki, JP;
Hideo Karasawa, Ibaraki, JP;
Yuuki Gotou, Ibaraki, JP;
Motoyuki Yabuuchi, Ibaraki, JP;
Yoichi Kowatari, Ibaraki, JP;
Yasushi Arai, Ibaraki, JP;
Kouji Ishikawa, Ibaraki, JP;
Kazunori Nakamura, Ibaraki, JP;
Nobuei Ariga, Ibaraki, JP;
Hideo Karasawa, Ibaraki, JP;
Yuuki Gotou, Ibaraki, JP;
Motoyuki Yabuuchi, Ibaraki, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
An engine lag down control system for construction machinery has a machinery body controller having first, second and third torque control units and a solenoid valve. The first torque control unit controls a torque control valve to a minimum pump torque corresponding to a target number of engine revolutions when a non-operated state of a control device has continued beyond a monitoring time. The second torque control unit controls the torque control valve such that the above-described minimum pump torque is held for a predetermined holding time subsequent to the operation of the control device from the non-operated state. The third torque control unit controls the torque control valve such that from a time point of a lapse of the predetermined holding time, the pump torque is gradually increased on a basis of a predetermined torque increment rate.