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. 14, 2013
Filed:
Jul. 14, 2008
Hidenobu Tsukada, Ushiku, JP;
Kazunori Nakamura, Tsuchiura, JP;
Tsuyoshi Nakamura, Tsuchiura, JP;
Yasuo Yamazaki, Ryuugasaki, JP;
Hidenobu Tsukada, Ushiku, JP;
Kazunori Nakamura, Tsuchiura, JP;
Tsuyoshi Nakamura, Tsuchiura, JP;
Yasuo Yamazaki, Ryuugasaki, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
This invention provides a traveling system for an engineering machine, adapted to limit a maximum traveling speed of the machine without causing decreases in engineering work efficiency or in accelerating performance during a start of traveling, and to improve fuel efficiency by suppressing a loss of engine output horsepower under the limited state of the maximum traveling speed. During fourth-gear shift control process, capacities of first and second hydraulic motorsare controlled in coordinative form and the second hydraulic motorhas its minimum tilting amount limited to a tilting amount limit q2cmin. In addition, when a tilting amount of the first hydraulic motorreaches a minimum tilting amount q1min, the enginehas its maximum engine speed limited to a first engine speed limit Ncmax1 (e.g., 1,800 rpm).