Hydraulic drive system for work machine
US10301793B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 2014 |
| Grant date | May 28, 2019 |
| Priority date | — |
| Expiry date | Nov 10, 2034 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/88
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
When hydraulic fluid discharged from a hydraulic actuator is to be recovered for driving a different hydraulic actuator, the recovery frequency is increased to achieve further energy saving. To this end, a pressure increasing circuit 36 is provided in which a communication pressure increasing valve 12 is disposed in a communication passage 26 that connects a bottom side line 23 of and a rod side line 24 a boom cylinder 4. A recovery control valve 11 is controlled such that, when a first operation unit 5 is operated in a boom lowering direction (own weight falling direction of the boom) and a second operation unit 6 is operated simultaneously, only if the pressure at the bottom side of the boom cylinder 4 is higher than the pressure at the arm cylinder side that is a recovery destination of hydraulic fluid, the recovery control valve 11 is opened to recover the flow rate discharged from the bottom side of the boom cylinder 4 to the arm cylinder side.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.