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:
Jul. 26, 2016
Filed:
May. 24, 2012
Kazuo Fujishima, Tsuchiura, JP;
Yusuke Kajita, Ushiku, JP;
Mitsuo Sonoda, Kasumigaura, JP;
Masatoshi Hoshino, Tsuchiura, JP;
Akira Nakayama, Tsuchiura, JP;
Junji Yamamoto, Kasumigaura, JP;
He Bao, Ushiku, JP;
Seiji Ishida, Hitachinaka, JP;
Shiro Yamaoka, Hitachi, JP;
Takashi Okada, Hitachinaka, JP;
Kazuo Fujishima, Tsuchiura, JP;
Yusuke Kajita, Ushiku, JP;
Mitsuo Sonoda, Kasumigaura, JP;
Masatoshi Hoshino, Tsuchiura, JP;
Akira Nakayama, Tsuchiura, JP;
Junji Yamamoto, Kasumigaura, JP;
He Bao, Ushiku, JP;
Seiji Ishida, Hitachinaka, JP;
Shiro Yamaoka, Hitachi, JP;
Takashi Okada, Hitachinaka, JP;
HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo, JP;
Abstract
A hydraulic working machine has an assist electric motor connected to an engine and a hydraulic pump. The emissions of air pollutants in the exhaust gas from the engine are minimized regardless of fluctuations in the load torque of the hydraulic pump. A specific revolution speed suitable for reducing the emissions of air pollutants is stored, and an engine is controlled using the specific revolution speed as a target revolution speed. The absorption torque of a hydraulic pump is subjected to high-pass filtering whereby a high-frequency component devoid of a trend component is obtained. Target assist torque is computed from the high-frequency component, and the assist electric motor is subjected to power running/generation control accordingly. A specific output torque range suitable for reducing the emissions of air pollutants is stored, and the target assist torque is corrected so that the trend component does not exceed the specific output torque range.