Hydraulic drive system for construction machine
US11214940B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2018 |
| Grant date | Jan 4, 2022 |
| Priority date | — |
| Expiry date | Feb 2, 2039 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/7142
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Even where the differential pressure across a directional control valve associated with each actuator is very small, flow dividing control of the plurality of directional control valves can be performed stable, and even where a demanded flow rate suddenly changes at the time of transition from composite action to single action or the like, a sudden change of the flow rate of hydraulic fluid to be supplied to each actuator is prevented to implement superior combined operability. Further, the meter-in loss of the directional control valves can be reduced to implement a high energy efficiency. To this end, a plurality of pressure compensating valves 7a, 7b and 7c for controlling such that the pressure in the downstream side of the meter-in opening of a plurality of directional control valves 6a, 6b and 6c becomes equal to the highest load pressure are individually arranged in the downstream side of meter-in openings of the plurality of directional control valves 6a, 6b and 6c, and demanded flow rates for the directional control valves 6a, 6b and 6c are calculated from input amounts of operation levers. Besides, the meter-in pressure loss of a predetermined directional control valve is…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.