Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
202 words
A method of operating a gasoline internal combustion spark ignition engine, which comprises separating the gasoline fuel by boiling point into at least two fractions, and separately supplying the fuel fractions to the combustion chamber of the engine in such a manner as to achieve in each cylinder a two-zone stratification of the charge at the instant of spark when the engine is operating at low and medium loads, the two-zone stratification consisting of two contiguous mixture clouds, a first of the two clouds lying in the vicinity of the spark plug and containing a higher concentration of the higher boiling point fuel fraction than the second cloud lying at a distance from the spark plug, the average composition of the fuel and the fuel-to-air ratio in the said second cloud being such that the second cloud undergoes auto-ignition subsequent to the instant of spark ignition of the first cloud, the auto-ignition of the second cloud being brought about by the increased temperature and pressure resulting from the advancing flame front in the first cloud and the timing of the auto-ignition of the second cloud thereby occurring at a predetermined time delay after the instant of spark ignition of the first cloud.
Claim 2
Independent Claim
202 words
A method of operating a gasoline internal combustion spark ignition engine, which comprises separating the gasoline fuel by boiling point into at least two fractions, and separately supplying the fuel fractions to the combustion chamber of the engine in such a manner as to achieve in each cylinder a two-zone stratification of the charge at the instant of spark when the engine is operating at low and medium loads, the two-zone stratification consisting of two contiguous mixture clouds, a first of the two clouds lying in the vicinity of the spark plug and containing a higher concentration of the higher boiling point fuel fraction than the second cloud lying at a distance from the spark plug, the average composition of the fuel and the fuel-to-air ratio in the said second cloud being such that the second cloud undergoes auto-ignition subsequent to the instant of spark ignition of the first cloud, the auto-ignition of the second cloud being brought about by the increased temperature and pressure resulting from the advancing flame front in the first cloud and the timing of the auto-ignition of the second cloud thereby occurring at a predetermined time delay after the instant of spark ignition of the first cloud.
Claim 3
Dependent Claim
24 words
A method as claimed in claim 1 , wherein the fuel is separated into three fractions, namely low, medium and high boiling point fractions.
Claim 4
Dependent Claim
57 words
A method as claimed in claim 2 , wherein the medium boiling point fraction comprises the components of the fuel have boiling points in the temperature range from 40° C. to 100° C., the low and high boiling point fractions comprising the remaining components of the fuel having boiling points below and above this temperature range, respectively.
Claim 5
Dependent Claim
20 words
A method as claimed in claim 1 , wherein exhaust gases are recirculated to the engine, either externally or internally.
Claim 6
Dependent Claim
29 words
A method as claimed in claim 4 , wherein the concentration of EGR gases is stratified into two zones one near and the other distant from the spark plug.
Claim 7
Dependent Claim
26 words
A method as claimed in claim 5 , wherein the higher concentration of EGR gases is located in the first cloud lying near the spark plug.
Claim 8
Dependent Claim
55 words
A method as claimed in claim 1 , wherein the fuel fraction with the higher or highest boiling point is injected as a liquid into a predetermined region of the engine intake system such that it is subsequently drawn into the combustion chamber to form a stratified cloud in the vicinity of the spark plug.
Claim 9
Dependent Claim
52 words
A method as claimed in claim 2 , wherein the medium boiling point fuel fraction is injected as a condensed liquid into a predetermined region of the engine intake system such that it is subsequently drawn into the combustion chamber to form a stratified cloud at a distance from the spark plug.
Claim 10
Dependent Claim
223 words
A gasoline internal combustion spark ignition engine having a fuel fractioning system ( 30 ) for separating the gasoline fuel by boiling point into at least two fractions, and means ( 17 , 18 , 19 ) for separately supplying the fuel fractions to the combustion chamber ( 100 ) of the engine in such a manner as to achieve in each cylinder a two-zone stratification of the charge at the instant of spark when the engine is operating at low and medium loads, the two-zone stratification consisting of two contiguous mixture clouds, a first of the two clouds lying in the vicinity of the spark plug ( 102 ) and containing a higher concentration of the higher boiling point fuel fraction than the second cloud lying at a distance from the spark plug ( 102 ), the average composition of the fuel and the fuel-to-air ratio in the said second cloud being such that the second cloud undergoes auto-ignition subsequent to the instant of spark ignition of the first cloud, the auto-ignition of the second cloud being brought about by the increased temperature and pressure resulting from the advancing flame front in the first cloud and the timing of the auto-ignition of the second cloud thereby occurring at a predetermined time delay after the instant of spark ignition of the first cloud.
Claim 11
Dependent Claim
223 words
A gasoline internal combustion spark ignition engine having a fuel fractioning system ( 30 ) for separating the gasoline fuel by boiling point into at least two fractions, and means ( 17 , 18 , 19 ) for separately supplying the fuel fractions to the combustion chamber ( 100 ) of the engine in such a manner as to achieve in each cylinder a two-zone stratification of the charge at the instant of spark when the engine is operating at low and medium loads, the two-zone stratification consisting of two contiguous mixture clouds, a first of the two clouds lying in the vicinity of the spark plug ( 102 ) and containing a higher concentration of the higher boiling point fuel fraction than the second cloud lying at a distance from the spark plug ( 102 ), the average composition of the fuel and the fuel-to-air ratio in the said second cloud being such that the second cloud undergoes auto-ignition subsequent to the instant of spark ignition of the first cloud, the auto-ignition of the second cloud being brought about by the increased temperature and pressure resulting from the advancing flame front in the first cloud and the timing of the auto-ignition of the second cloud thereby occurring at a predetermined time delay after the instant of spark ignition of the first cloud.