US 5,495,839 AGranted

Engine fuel injection controller

AssigneeNissan Motor Co., Ltd.

InventorsSatoshi Samejima, Hirofumi Tsuchida, Koji Ishihara

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Abstract

The delay of fuel flow in an intake passage of an engine is divided into two categories, namely a short-term delay having a relatively fast time constant and a long-term delay having a relatively slow time constant. The corrections for each delay are stored separately depending on the engine running conditions. A mechanism is provided for estimating the particle diameter of the fuel spray, and either the long-term delay correction is modified so that it increases or the short-term delay correction is modified so that it decreases as the particles of fuel spray become smaller. The basic fuel injection amount during transient engine running conditions is corrected by applying the delay flow correction thereby modified, and error in the air-fuel ratio during transient conditions due to atomization of fuel particles is prevented.

Claims6

Dependent claims

An engine fuel injection controller for use with an engine including a cylinder, an intake passage provided with an intake valve for aspirating air into said cylinder, a throttle for regulating an air flowrate in said passage, an injector situated between said throttle and said intake valve for injecting fuel into said passage, and means for promoting atomization of the fuel spray from said injector, said controller comprising:

means for detecting engine running conditions;
control means functioning to
compute a basic fuel injection amount based on said engine running conditions,
store short-term delay flow corrections depending on various engine running conditions, each of said corrections corresponding to a delay of fuel flow in said passage with a relatively fast time constant,
store long-term delay flow corrections depending on various engine running conditions, each of said corrections corresponding to a delay of fuel flow in said passage with a relatively slow time constant,
read a stored short-term delay flow correction based on said detected engine running conditions,
read a stored long-term delay flow correction based on said detected engine running conditions,
estimate a particle diameter of the fuel spray,
modify at least one of said read delay flow corrections such that said long-term delay flow correction is increased, and said short-term delay flow correction is decreased, as the particle diameter of the fuel spray is smaller,
correct said basic fuel injection amount based on said modified delay flow corrections to determine a corrected amount of fuel;
and
means for controlling said injector to inject said corrected amount of fuel.

9 more elements

An engine fuel injection controller for use with an engine comprising a cylinder, an intake passage provided with an intake valve for aspirating air into said cylinder, a throttle for regulating an air flowrate in said passage, and injector situated between said throttle and said intake valve for injecting fuel into said passage, and means for promoting atomization of the fuel spray from said injector, said controller comprising:

means for detecting engine running conditions;
means for detecting a temperature of a part of said passage where sprayed fuel has adhered;
a control means functioning to
compute a basic fuel injection amount based on aid engine running conditions,
store short-term delay flow corrections depending on various engine running conditions and temperatures of the part where fuel is adhering, each of said corrections corresponding to a delay of fuel flow in said passage with a relatively fast time constant,
store long-term delay flow corrections depending on various engine running conditions and temperatures of the part where fuel is adhering, each of said corrections corresponding to a delay of fuel flow in said passage with a relatively slow time constant,
read a stored short-term delay flow correction based on said detected engine running conditions and said detected temperature,
read a stored long-term delay flow correction based on said detected engine running conditions and said detected temperature,
estimate a particle diameter of the fuel spray,
modify at least one of the read delay flow corrections such that said long-term delay flow correction is increased, and said short-term delay flow correction is decreased as the particle diameter of the fuel spray is smaller,
correct said basic injection amount based on said modified delay flow corrections to determine a corrected amount of fuel;
and
means for controlling said injector to inject said corrected amount of fuel.

10 more elements

Dependencies are inferred from the claim text.