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:
Nov. 11, 2014
Filed:
Sep. 02, 2010
Tsuyoshi Nakamura, Tsuchiura, JP;
Kouji Ishikawa, Tsuchiura, JP;
Yasushi Arai, Tsuchiura, JP;
Hidenobu Tsukada, Tsuchiura, JP;
Shohei Kamiya, Tsuchiura, JP;
Tsuyoshi Nakamura, Tsuchiura, JP;
Kouji Ishikawa, Tsuchiura, JP;
Yasushi Arai, Tsuchiura, JP;
Hidenobu Tsukada, Tsuchiura, JP;
Shohei Kamiya, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A hydraulic drive system for a hydraulic working machine sets a delivery pressure at a preset value upon raising a temperature of exhaust gas to a temperature needed for combustion of particulate matter by increasing a load to be applied to an engine. In a non-operation state, a variable restrictor is controlled by a controller and a delivery pressure control valve to increase a delivery pressure of a variable displacement hydraulic pump, so that the load is increased to raise the temperature of exhaust gas to the temperature needed for the particulate matter combustion. At this time, the controller controls the delivery pressure control valve such that a delivery pressure to be detected by a delivery pressure sensor will conform with a preset reference delivery pressure. The reference delivery pressure is set to a minimum pressure that can provide the exhaust gas with combustion heat.