Method and apparatus for controlling amount of fuel injected into engine cylinders

Claim 3

A method as claimed in claim 1, wherein said at least one engine parameter includes engine speed.

Claim 4

A method as claimed in claim 1, wherein said at least one engine parameter includes engine load.

Claim 5

A method as claimed in claim 3, wherein said engine load is detected by measuring a stroke of an accelerator pedal of said engine.

Claim 6

A method as claimed in claim 1, wherein said step of modifying comprising the steps of: (a) determining whether said engine is in idle state; (b) computing a correction factor K using said at least one engine parameter when said engine is not in idle state; (c) modifying said correction amounts by multiplying said correction factor K thereto, said multiplying of correction amounts by said correction factor K not being performed when said engine is in said idle state.

Claim 7

Apparatus for controlling the amount of fuel injected into a multi-cylinder internal combustion engine, comprising: means for detecting a rotational speed of said engine at predetermined intervals only when the engine is in a steady idle state to produce a plurality of engine speed data N for each of the cylinders of said engine so as to detect the variation in torque caused by each combustion; means for detecting operational parameters of said engine including engine load; computing means for: (a) obtaining a minimum engine speed N L and a maximum engine speed N H from a plurality of engine speed data Ni for each cylinder wherein "i" is a positive integer indicating a crank angle position where engine speed data is detected; (b) obtaining a difference ΔNj=NH-NL between said minimum and maximum engine speed data for each of said cylinders wherein "j" is a positive integer indicating a cylinder number; (c) obtaining an average difference ΔN using a plurality of difference values ΔNj computed for each of said cylinders; (d) obtaining a deviation by subtracting said average difference Δe,ovs/N/ from said difference ΔNj for each of said cylinders; (e) obtaining a unit correction factor β using an absolute value of said deviation for each of said cylinders; (f) updating a correction amount Δqj using said unit correction factor β in accordance with the value of said deviation; (g) determining whether said engine is in idle state; (h) computing a correction factor K using said at least one engine parameter when said engine is not in said idle state; (i) modifying said correction amounts Δqj by multiplying said correction factor K thereto, said correction amounts Δqj not being multiplied by said correction factor K when said engine is in said idle state; (j) obtaining a basic fuel amount Qj for each of said cylinders using engine speed data and engine load data; (k) correcting said basic fuel amount Qj by said correction amounts Δqj which have been modified if said engine is not in said idle state; and (l) producing a control signal using corrected basic fuel amount; and means for controlling the amount of fuel injected into the engine cylinders in accordance with said control signal.

Claim 8

Apparatus for controlling the amount of fuel injected into a multi-cylinder internal combustion engine, comprising: means for detecting a rotational speed of said engine at predetermined intervals only when the engine is in a steady idle state to produce a plurality of engine speed data N for each of the cylinders of said engine so as to detect the variation in torque caused by each combustion; means for detecting operational parameters of said engine including engine load; computing means for: (a) obtaining a minimum engine speed N L and a maximum engine speed N H from a plurality of engine speed data Ni for each cylinder wherein "i" is a positive integer indicating a crank angle position where engine speed data is detected; (b) obtaining a difference ΔNj=NH-NL between said minimum and maximum engine speed data for each of said cylinders wherein "j" is a positive integer indicating a cylinder number; (c) obtaining an average difference ΔN using a plurality of difference values ΔNj computed for each of said cylinders; (d) obtaining a deviation by subtracting said average difference Δe,ovs/N/ from said difference ΔNj for each of said cylinders; (e) obtaining a unit correction factor β using an absolute value of said deviation for each of said cylinders; (f) updating a correction amount Δqj using said unit correction factor β in accordance with the value of said deviation; (g) determining whether said engine is in idle state; (h) computing a correction factor K using said at least one engine parameter when said engine is not in said idle state; (i) modifying said correction amounts Δqj by multiplying said correction factor K thereto, said correction amounts Δqj not being multiplied by said correction factor K when said engine is in said idle state; (j) obtaining a basic fuel amount Qj for each of said cylinders using engine speed data and engine load data; (k) correcting said basic fuel amount Qj by said correction amounts Δqj which have been modified if said engine is not in said idle state; and (l) producing a control signal using corrected basic fuel amount; and means for controlling the amount of fuel injected into the engine cylinders in accordance with said control signal.

Claim 9

Apparatus as claimed in claim 6, wherein said means for detecting comprises: (a) a disc including a plurality of teeth on a peripheral portion thereof arranged to rotate in synchronization with the engine crankshaft; and (b) an electromagnetic pickup responsive to the passage of each tooth of said disc.

Claim 10

Apparatus as claimed in claim 6, wherein said means for controlling comprises a distributor injection pump having a spill ring arranged to be moved by an electromagnetic actuator responsive to said control signal.