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:
Feb. 12, 2013
Filed:
Sep. 07, 2007
Kazunori Nakamura, Tsuchiura, JP;
Kouji Ishikawa, Kasumigaura, JP;
Nobuei Ariga, Tsuchiura, JP;
Akihiro Narazaki, Kasumigaura, JP;
Kazunori Nakamura, Tsuchiura, JP;
Kouji Ishikawa, Kasumigaura, JP;
Nobuei Ariga, Tsuchiura, JP;
Akihiro Narazaki, Kasumigaura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
Torque control for a construction machine three-pump system that can accurately control the total absorption torque of first, second, and third hydraulic pumps and effectively use the output torque of an engine. A pump base torque computation sectioncalculates a pump base torque Tr from a target rotation speed. A subtraction sectioncalculates a reference value Tf for the maximum absorption torque available to the first and second hydraulic pumpsby subtracting a third pump reference absorption torque Tr from the pump base torque Tr. A correction torque computation sectioncalculates a correction torque value from the delivery pressure of the third hydraulic pump. An addition sectioncalculates a target absorption torque Tn by adding the correction torque value Tm to the reference value Tf. A first regulatoris controlled so as to obtain the target absorption torque Tn.