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. 08, 2009
Filed:
Nov. 18, 2005
Nobuei Ariga, Tsuchiura, JP;
Kazunori Nakamura, Tsuchiura, JP;
Kouji Ishikawa, Kasumigaura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
When a mode selection command selects an economy mode, a mode selectoris turned on and outputs an engine revolution speed modification value ΔN(ΔN=ΔN) computed by an engine-revolution-speed modification value computing section. A subtractersubtracts the engine revolution speed modification value ΔNfrom a rated target revolution speed Nmax, thereby computing a target engine revolution speed NR. The computing sectioncomputes the engine revolution speed modification value ΔNdepending on a pump delivery pressure mean value Pm. In a table stored in a memory, the relationship between Pm and ΔNis set such that when Pm is not higher than PA near a midpoint pressure, ΔNis 0 and when Pm exceeds PA, ΔNis increased with an increase of Pm. Thus, the revolution speed of a prime mover is reduced by mode selection so as to improve fuel economy.