Hydraulic control system for construction machine
US5267440A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1992 |
| Grant date | Dec 7, 1993 |
| Priority date | — |
| Expiry date | May 4, 2012 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02F9/2296
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In a controller (229) of a hydraulic control system for construction machines, a valve control signal calculating function (301) works such that when an operation pattern signal (A-I) for actuators (201, 202 . . . ) is outputted, it selects corresponding one of plural output patterns for an auxiliary valve control pressure stored, as a function of a differential pressure signal between a pump delivery pressure and a maximum load pressure, in relation to the operation pattern signals, followed by calculating an auxiliary valve control pressure (Pc) dependent upon the differential pressure signal based on the selected output pattern, and also selects corresponding one of plural sets of rates of change (K . . . , K . . . ) for the auxiliary valve control pressure stored in relation to the operation pattern signals, followed by combining the calculated auxiliary valve control amount with the selected set of speed changes to calculate each of valve control signals (S21-S26).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.