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. 13, 2008
Filed:
Nov. 15, 2004
Tsuyoshi Nakamura, Ibaraki-ken, JP;
Kazunori Nakamura, Tsuchiura, JP;
Toichi Hirata, Ushiku, JP;
Genroku Sugiyama, Ryuugasaki, JP;
Kentaro Itoga, Abiko, JP;
Tsuyoshi Nakamura, Ibaraki-ken, JP;
Kazunori Nakamura, Tsuchiura, JP;
Toichi Hirata, Ushiku, JP;
Genroku Sugiyama, Ryuugasaki, JP;
Kentaro Itoga, Abiko, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A modification torque ΔT and a torque converter speed ratio e is computed from input and output revolution speeds of a torque converter. A first determination coefficient α corresponding to the speed ratio e, and a second determination coefficient β corresponding to a pump pressure are computed. A selectorselects the smaller one of these coefficients as a determination coefficient γ, and the modification torque ΔT is multiplied by γ to provide a modification torque ΔTA. An adderadds the modification torque ΔTA (negative value) to a pump base torque TR to provide a modified pump base torque TRA, whereby a maximum pump absorption torque TRA is controlled so as to become TRA. The maximum pump torque reducing control can then be performed while accurately confirming a work situation during the combined operation of travel and a working actuator.