Construction machine
US10995474B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 2019 |
| Grant date | May 4, 2021 |
| Priority date | — |
| Expiry date | Jan 10, 2039 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/7142
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Flow control over a hydraulic pump and flow dividing control of a plurality of directional control valves associated with actuators can stably be exercised even in a case in which differential pressures across the directional control valves are quite low, an abrupt change in a flow rate of the hydraulic fluid supplied to each actuator is prevented and excellent combined operability is realized even in an abrupt change in a demanded flow rate at a time of transition from a combined operation to a sole operation, and realizing excellent combined operability, and a meter-in loss in each directional control valve is reduced to realize high energy efficiency. Demanded flow rates of the directional control valves are calculated from input amounts of operation levers, openings of flow control valves are controlled using the demanded flow rates, a meter-in pressure loss of a predetermined directional control valve is calculated from the demanded flow rates and meter-in opening areas of the directional control valves, and a set pressure of an unloading valve is controlled using a value of the meter-in pressure loss.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.