Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
HYDRAULIC ENERGY RECOVERY DEVICE FOR WORK MACHINE
Document Type and Number:
WIPO Patent Application WO/2018/055723
Kind Code:
A1
Abstract:
In order to avoid reaching an overload relief set pressure and suppress switching shock, thereby ensuring good operability in a hydraulic energy recovery device wherein return oil in a hydraulic cylinder is pressurized and recovered, this hydraulic energy recovery device for a work machine is equipped with: a connecting/pressurization passage that connects the exhaust side and the intake side of a hydraulic cylinder when a driven body is dropping due to its own weight, thereby enabling the pressure of the pressurized oil on the exhaust side to be increased; a connecting/pressurization valve arranged in the connecting/pressurization passage and capable of adjusting the pressure and/or the flow volume in the connecting/pressurization passage; a recovery-side passage and a recovery control valve or a reuse-side passage and a reuse control valve capable of reusing pressurized oil discharged from the hydraulic cylinder when the driven body is dropping due to its own weight; and a control device. When the pressure on the discharge side of the hydraulic cylinder reaches a predetermined high-load set pressure the control device reduces the degree of opening of the connection/pressurization valve in accordance with the increase in pressure immediately after the set pressure has been attained, and gradually reduces the degree of opening of the connection/pressurization valve over time.

Inventors:
HIJIKATA Seiji (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
ISHIKAWA Kouji (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
IMURA Shinya (Hitachi Construction Machinery Co. Ltd., 650, Kandatsumachi, Tsuchiura-sh, Ibaraki 13, 〒3000013, JP)
Application Number:
JP2016/077961
Publication Date:
March 29, 2018
Filing Date:
September 23, 2016
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HITACHI CONSTRUCTION MACHINERY CO., LTD. (16-1, Higashiueno 2-chome Taito-k, Tokyo 15, 〒1100015, JP)
International Classes:
F15B21/14; E02F9/22; F15B11/00; F15B11/024
Domestic Patent References:
WO2014112566A12014-07-24
Foreign References:
JP2009127643A2009-06-11
Attorney, Agent or Firm:
KAICHI IP (3-16, Nihonbashi-muromachi 4-chome Chuo-k, Tokyo 22, 〒1030022, JP)
Download PDF: