Patent · US Expired

Method and apparatus to control ignition timing during starting of an externally ignited internal combustion engine

US4594981A · kind A · utility

2Cited by
7References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 6, 1984
Grant dateJun 17, 1986
Priority date
Expiry dateSep 6, 2004

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02T10/40
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

Abstract

To place the maximum combustion pressure, which occurs upon ignition, after the piston of an internal combustion engine (ICE) has passed upper dead-center (UDC) position upon starting, a predetermined time interval (Ti) is subtracted from the expected time the piston reaches UDC position, as determined by the time taken for a predetermined angular distance of the crankshaft to rotate; the time between the predetermined angular distances is extrapolated to determine the projected, or expected time of the UDC position. The predetermined time interval (Ti), which may be made dependent upon engine temperature, is then subtracted and the actual firing time computed, for example by counting-out in a counter the differential time interval determined by the subtraction. The timing intervals are preferably derived from a segmental marker system (20,21; A1,A2), in a counter (1), the extrapolation carried out in a multiplier (2) and the subtracting in a subtraction circuit (3). The system is preferably enabled upon closing of the starter switch (S) and may be disabled when a down-counter, determining the actual timing interval, has a negative count output.

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