Patent · US Active

Swing drive controlling system for construction machine

US9022749B2 · kind B2 · utility

9Cited by
14References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 30, 2009
Grant dateMay 5, 2015
Priority date
Expiry dateJun 24, 2031

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF15B2211/7058
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

The system includes: a variable displacement hydraulic pump supplying pressure oil to a hydraulic actuator; a pressure detector detecting a pump discharge pressure from the hydraulic pump; a control valve controlling a supply of the pressure oil to the hydraulic actuator; a controller controlling a pump displacement of the hydraulic pump; a hydraulic motor rotating an upper structure of the construction machine; a swing relief valve defining a relief pressure of the hydraulic motor; and a control lever switching a control valve for the hydraulic motor. The controller includes: an adjuster that, when a pump discharge pressure detected by the pressure detector exceeds a first set value, conducts an adjustment to reduce the pump displacement; and a canceller that cancels the adjustment when the pump discharge pressure falls below a second set value. The second set value is equal to or larger than the first set value.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.