Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
307 words
A multiple cylinder internal combustion engine including a first group of cylinder means, a second group of cylinder means, an intake system comprising main intake passage means, first intake passage means branched from said main intake passage means and leading to said first group of cylinder means, second intake passage means branched from said main intake passage means and leading to said second group of cylinder means, first fuel supply means for providing a supply of fuel to said first intake passage means, second fuel supply means for providing a supply of fuel to said second intake passage means, first exhaust passage means leading from said first group of cylinder means for passage of exhaust gas therefrom, exhaust gas sensing means including an oxygen concentration detecting means disposed in said first exhaust passage means for providing an output signal in accordance with the concentration of oxygen in the exhaust gas, first air-fuel ratio control means for controlling the first fuel supply means in accordance with the output of the exhaust gas sensing means so as to provide a first intake mixture of a first predetermined air-fuel ratio, second air-fuel ratio control means for controlling the second fuel supply means in accordance with the first predetermined air-fuel ratio to provide a second intake mixture of a second air-fuel ratio which is a predetermined relationship with respect to the first air-fuel ratio, mixing preventing means provided in said intake system upstream of said first and second fuel supply means for preventing said first and second intake mixtures from being mixed with each other due to pulsations in said intake system, and second exhaust passage means extending from said second group of cylinder means and merged with the first exhaust passage means, said first exhaust passage means being provided downstream of the exhaust gas sensing means with backflow preventing means.
Claim 2
Dependent Claim
307 words
A multiple cylinder internal combustion engine including a first group of cylinder means, a second group of cylinder means, an intake system comprising main intake passage means, first intake passage means branched from said main intake passage means and leading to said first group of cylinder means, second intake passage means branched from said main intake passage means and leading to said second group of cylinder means, first fuel supply means for providing a supply of fuel to said first intake passage means, second fuel supply means for providing a supply of fuel to said second intake passage means, first exhaust passage means leading from said first group of cylinder means for passage of exhaust gas therefrom, exhaust gas sensing means including an oxygen concentration detecting means disposed in said first exhaust passage means for providing an output signal in accordance with the concentration of oxygen in the exhaust gas, first air-fuel ratio control means for controlling the first fuel supply means in accordance with the output of the exhaust gas sensing means so as to provide a first intake mixture of a first predetermined air-fuel ratio, second air-fuel ratio control means for controlling the second fuel supply means in accordance with the first predetermined air-fuel ratio to provide a second intake mixture of a second air-fuel ratio which is a predetermined relationship with respect to the first air-fuel ratio, mixing preventing means provided in said intake system upstream of said first and second fuel supply means for preventing said first and second intake mixtures from being mixed with each other due to pulsations in said intake system, and second exhaust passage means extending from said second group of cylinder means and merged with the first exhaust passage means, said first exhaust passage means being provided downstream of the exhaust gas sensing means with backflow preventing means.
Claim 3
Dependent Claim
17 words
An engine in accordance with claim 1 in which said mixing preventing means comprises check valve means.
Claim 4
Dependent Claim
17 words
An engine in accordance with claim 1 in which said mixing preventing means comprises expansion chamber means.
Claim 5
Dependent Claim
74 words
An engine in accordance with claim 1 in which said first and second groups of cylinder means have the same number of cylinders, the cylinders in each group having branched intake passages which are merged into an intake passage, said mixing preventing means being provided in said intake passage in said first group, each group of cylinder means including cylinders which are not adjacent to each other in respect of the order of combustion.
Claim 6
Dependent Claim
83 words
An engine in accordance with claim 1 in which said first and second fuel supply means comprise fuel injection valve means, said first air-fuel ratio control means including circuit means for providing output pulses the width of which is determined in accordance with an engine operating condition signal and the output of the exhaust gas sensing means, said second air-fuel ratio control means including modifying circuit means for modifying the output pulses of the circuit means in the first air-fuel ratio control means.
Claim 7
Dependent Claim
51 words
An engine in accordance with claim 1 in which said second air-fuel ratio control means includes engine operating condition sensing means for producing an engine operating condition signal and modifying means for determining said predetermined relationship between the first and second air-fuel ratios in accordance with the engine operating condition signal.
Claim 8
Dependent Claim
47 words
An engine in accordance with claim 6 in which said engine operating condition sensing means includes engine temperature sensing means, said modifying means being adapted to determine the predetermined relationship so that said second intake mixture is enriched when the engine temperature is below a warmed-up temperature.
Claim 9
Dependent Claim
36 words
An engine in accordance with claim 6 in which said engine operating condition sensing means includes engine load sensing means so that said second intake mixture is enriched under light load and heavy load engine operation.