Asynchronous fuel injection method

Claim 1

A method of controlling an amount of fuel injection in accordance with information from a sensor within an engine, wherein an asynchronous fuel injection pulse width for injecting fuel in asynchronism with a crank angle is determined by a calculation periodically performed in asynchronism with the crank angle, said method comprising the steps of: calculating an amount of increase of a throttle flow area during a period between a time k-1 and a time k in accordance with throttle angles at the time k-1 and k; and determining the asynchronous fuel injection pulse width at the time k on the basis of the calculated amount of increase of the throttle flow area; wherein the asynchronous fuel injection pulse width T IS (k) at the time k is determined by the following expression ##EQU9## where: K I is a coefficient determined by characteristics of an injector, N(k) is an engine r.p.m. at the time k, E(k-1) is a quantity of air per unit throttle area, calculated at the time k-1, b is an area of throttle valve, θ (k-1) is a throttle angle at the time k-1, and θ (k) is a throttle angle at the time k.

Claim 2

A method of controlling an amount of fuel injection in accordance with information from a sensor within an engine, wherein an asynchronous fuel injection pulse width for injecting fuel in asynchronism with a crank angle is determined by a calculation periodically performed in asynchronism with the crank angle, said method comprising the steps of: calculating an amount of increase of a throttle flow area during a period between a time k-1 and a time k in accordance with throttle angles at the time k-1 and k; and determining the asynchronous fuel injection pulse width at the time k on the basis of the calculated amount of increase of the throttle flow area; wherein the asynchronous fuel injection pulse width T IS (k) at the time k is determined by the following expression ##EQU9## where: K I is a coefficient determined by characteristics of an injector, N(k) is an engine r.p.m. at the time k, E(k-1) is a quantity of air per unit throttle area, calculated at the time k-1, b is an area of throttle valve, θ (k-1) is a throttle angle at the time k-1, and θ (k) is a throttle angle at the time k.

Claim 3

A method of controlling an amount of fuel injection in according with information from a sensor within an engine, wherein an asynchronous fuel injection pulse width for injecting fuel in asynchronism with a crank angle is determined by calculation periodically performed in asynchronism with the crank angle, said method comprising the steps of: calculating a throttle flow area at a time k-1 in accordance with a throttle angle at the time k-1; calculating an amount of increase of the throttle flow area during a period between the time k-1 and a time k in accordance with throttle angles at the time k-1 and the time k; and determining the asynchronous fuel injection pulse width at the time k on the basis of the calculated amount of increase of the throttle flow area and the calculated throttle flow area; wherein the asynchronous fuel injection pulse width T IS at the time k is determined by the following expression: ##EQU10## where: T p (k-1) is a basic injection pulse width calculated at the tim k-1, a is a flow area when a throttle valve is fully closed, b is an area of the throttle valve, θ (k-1) is a throttle angle at the time k-1, and θ (k) is a throttle angle at the time k.

Claim 4

A method of controlling an amount of fuel injection in according with information from a sensor within an engine, wherein an asynchronous fuel injection pulse width for injecting fuel in asynchronism with a crank angle is determined by calculation periodically performed in asynchronism with the crank angle, said method comprising the steps of: calculating a throttle flow area at a time k-1 in accordance with a throttle angle at the time k-1; calculating an amount of increase of the throttle flow area during a period between the time k-1 and a time k in accordance with throttle angles at the time k-1 and the time k; and determining the asynchronous fuel injection pulse width at the time k on the basis of the calculated amount of increase of the throttle flow area and the calculated throttle flow area; wherein the asynchronous fuel injection pulse width T IS at the time k is determined by the following expression: ##EQU10## where: T p (k-1) is a basic injection pulse width calculated at the tim k-1, a is a flow area when a throttle valve is fully closed, b is an area of the throttle valve, θ (k-1) is a throttle angle at the time k-1, and θ (k) is a throttle angle at the time k.