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 (JP)
ISHIKAWA KOUJI (JP)
IMURA SHINYA (JP)
ISHIKAWA KOUJI (JP)
IMURA SHINYA (JP)
Application Number:
PCT/JP2016/077961
Publication Date:
March 29, 2018
Filing Date:
September 23, 2016
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACH CO (JP)
International Classes:
F15B21/14; E02F9/22; F15B11/00; F15B11/024
Domestic Patent References:
| WO2014112566A1 | 2014-07-24 | |||
| WO2016051579A1 | 2016-04-07 | |||
| WO2014112566A1 | 2014-07-24 |
Foreign References:
| JP2009127643A | 2009-06-11 |
Other References:
See also references of EP 3517789A4
Attorney, Agent or Firm:
KAICHI IP (JP)
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