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:
Mar. 27, 2018
Filed:
Jul. 24, 2014
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Takatoshi Ooki, Kasumigaura, JP;
Seiji Hijikata, Tsukuba, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
Energy regeneration system does not affect operation of a hydraulic actuator except when a relief valve is operating, by connecting an actuator hydraulic line to a regeneration hydraulic motor with a small pressure loss during regeneration, and ensures holding pressure when the energy cannot be regenerated. A first valve device disposed between actuator hydraulic lines and a regeneration hydraulic motor, has a throttle passage capable of increasing pressure in the higher pressure side actuator hydraulic line to a set pressure of the relief valves. A second valve device disposed in parallel with the first valve device between the actuator hydraulic lines and the regeneration hydraulic motor, is switched from a close to an open position by pressure between the first valve device and the regeneration hydraulic motor when pressure between the first valve device and the regeneration hydraulic motor increases to approach the set pressure of the swing relief valve.