US 5,469,831 AGranted

Fuel supply control system for an automotive engine

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorTatsuhiko Takahashi

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Abstract

A fuel supply control system for an automotive engine determines a property of the fuel, such as the fifty percent distillation temperature T.sub.50 thereof, and the fuel injectors of the engine are controlled in accordance with the determined fuel property. When the engine is idling and the coolant water temperature WT of the engine is decreasing, the amplitude X of the feedback correction factor K.sub.2 for proportional-plus-integral control action is measured a number of times, and an average amplitude X.sub.0 thereof is calculated. The property of said fuel is determined on the basis of the thus calculated average amplitude X.sub.0 and the coolant water temperature WT using a two-dimensional map which gives the value of T.sub.50 as a function of the amplitude X of the feedback correction factor K.sub.2 and the coolant water temperature WT. The thus determined index T.sub.50 is stored in a RAM backed up by a battery. When a new fuel is supplied to the fuel tank, the value of index T.sub.50 is cleared to determine the index afresh.

Claims6

Dependent claims

A fuel supply control system for an internal combustion engine, comprising:

fuel supply means for supplying a fuel to said internal combustion engine;
air/fuel ratio sensor means for detecting an air/fuel ratio of a mixture of air and fuel supplied to said internal combustion engine;
and
fuel supply control means, having all input coupled to said air/fuel ratio sensor means, for controlling said fuel supply means to adjust said air/fuel ratio to a theoretical ratio using a feedback control method based on an output of said air/fuel ratio sensor means;
wherein said fuel supply control means includes:
feedback correction factor calculation means for calculating a feedback correction factor from a deviation of said air/fuel ratio detected by said air/fuel ratio sensor means from said theoretical ratio;
amplitude measurement means for determining an amplitude of said feedback correction factor;
and fuel property judgment means for determining a property of said fuel on the basis of said amplitude of said feedback correction factor;
said fuel supply control means controlling said fuel supply means in accordance with said property of said fuel determined by said fuel property judgment means.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/339,194Filed 10 Nov 1994
Priority: JP 5-28337612 Nov 1993
Granted: 28 Nov 1995
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

F02D 41/249
Methods for rewriting: methods for preventing the loss of data
F02D 19/061
To adjust the fuel mass or volume flow: by controlling fuel injectors
F02D 19/0649
Characterised by the type of fuels: liquid fuels having different boiling temperatures, volatilities, densities, viscosities, cetane or octane numbers
F02D 19/088
With determination of densities, viscosities, composition, concentration or mixture ratios of fuels: by estimation, i.e. without using direct…