Patent · US Expired

Hydraulically-actuated electronically-controlled unit injector having stroke-controlled piston and methods of operation

US5181494A · kind A · utility

55Cited by
32References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 11, 1991
Grant dateJan 26, 1993
Priority date
Expiry dateOct 11, 2011

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02T10/12
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

Abstract

In a hydraulically-actuated electronically-controlled unit injector, the viscosity of the actuating fluid used to actuate the unit injector varies with ambient temperature and affects the magnitude of pressure drops in the actuating fluid circuit. Such variations in viscosity affect the magnitude of the fuel delivery command pulsewidth and/or actuating fluid pressure required for engine startup versus that required for normal engine operation. The present invention provides an improved hydraulically-actuated electronically-controlled unit injector and methods of operation which compensate for variations in the viscosity of the actuating fluid used to hydraulically actuate a piston. The stroke of the piston is controlled electronically and/or mechanically in order to achieve an appropriate amount of fuel injection.

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