Global Patent Index - EP 0306906 A3

EP 0306906 A3 19890726 - FEEDBACK CONTROL DEVICE FOR THE AIR-FUEL RATIO OF A COMBUSTION ENGINE

Title (en)

FEEDBACK CONTROL DEVICE FOR THE AIR-FUEL RATIO OF A COMBUSTION ENGINE

Publication

EP 0306906 A3 19890726 (DE)

Application

EP 88114559 A 19880907

Priority

AT 227887 A 19870909

Abstract (en)

[origin: EP0306906A2] Device for controlling the air-fuel ratio ( lambda ) of a lean-burn engine (1) as a function of fluctuations in the speed of the latter. A speed analysing circuit (22) is provided, which analyses an electrical speed signal for fluctuations. For this purpose the speed analysing circuit (22) has a high-pass filter (24), a differentiator (25) and a comparator post-connected to this, whose output (26a) is connected to a digital counter (27) and which compares the filtered and differentiated speed signal with a threshold value and, when this is exceeded, varies the counter reading of the counter (27) within a measuring period predetermined by a timer (28). The air-fuel ratio ( lambda ) is controlled according to the counter reading at the end of each measuring period which represents a measure of unsmooth running. <IMAGE>

IPC 1-7

F02D 41/14

IPC 8 full level

F02D 41/14 (2006.01)

CPC (source: EP)

F02D 41/1498 (2013.01); F02D 2200/1015 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT DE FR GB IT NL SE

DOCDB simple family (publication)

EP 0306906 A2 19890315; EP 0306906 A3 19890726; AT 388029 B 19890425; AT A227887 A 19880915

DOCDB simple family (application)

EP 88114559 A 19880907; AT 227887 A 19870909