Loading patent…
AssigneeHonda Giken Kogyo Kabushiki Kaisha
InventorsToru Yano, Eisuke Kimura, Masanori Hayashi, Yusuke Tatara, Toshio Yokoyama, Kenichiro Kinoshita
Estimating the term…
A system for controlling fuel injection in an internal combustion engine such that when the target air-fuel ratio is switched from a rich value to a lean value, the air-fuel ratios are switched to the lean value by sequentially decreasing the amount of fuel injected into the cylinders, for example in a four cylinder engine into the #1, #2, #3 and #4 cylinders, with predetermined time differences. During this time, an electronic air control valve (EACV) is controlled in such a manner that it is stepwise opened with the switching of the air-fuel ratios for the #1, #2, #3 and #4 cylinders, thereby causing the engine torque to remain the same to prevent the generation of a torque shock. When the target air-fuel ratio has been switched from the lean level to the rich level, the amounts of fuel injected into the #1, #2, #3 and #4 cylinders are controlled in such a manner that they are sequentially increased with predetermined time differences, and the EACV is controlled in such a manner that it is stepwise closed. Thus, it is possible to avoid the generation of a torque shock, while preventing the degradation of the emission during switching of the air-fuel ratio.
An air-fuel control system in an internal combustion engine, comprising a fuel injection valve provided at each of plural cylinders, a target air-fuel ratio setting means for setting a target air-fuel ratio based on an operational state of the internal combustion engine, and a fuel injection amount control means for separately changing an amount of fuel injected by each said fuel injection valve based on the target air-fuel ratio when said target air-fuel ratio setting means has switched the target air-fuel ratio, said fuel injection amount control means sequentially and separately changing said amounts of fuel injected by each of the respective said fuel injection valves at predetermined timing intervals for each said fuel injection valve, said timing intervals being based on an elapsed number of top dead center positions occurring in said cylinders, said fuel injection amount control means including means for changing said timing intervals.
In an air-fuel control system in an internal combustion engine having a fuel injection valve provided at each of plural cylinders, a target air-fuel ratio setting means for setting a target air-fuel ratio based on an operational state of the internal combustion engine, and a fuel injection amount control means for separately changing an amount of fuel injected by each fuel injection valve based on the target air-fuel ratio, an improvement comprising, said fuel injection amount control means sequentially and separately changing the amounts of fuel injected at predetermined timing intervals greater than a timing interval between successive fuel injections by each of said fuel injection valves and changing said predetermined timing intervals based on the operational state of the engine when said target air-fuel ratio setting means switches the target air-fuel ratio, said predetermined timing intervals being based on an elapsed number of top dead center positions occurring in said cylinders.
An air-fuel ratio control system in an internal combustion engine, comprising a fuel injection valve provided at each of plural cylinders, a target air-fuel ratio setting means for setting a target air-fuel ratio among a plurality of predetermined air-fuel ratios including a lower one and a higher one, based on an operational state of the internal combustion engine, and a fuel injection amount control means for separately changing an amount of fuel injected by each said fuel injection valve based on a change in the target air-fuel ratio, in which when said target air-fuel ratio setting means has switched the target air-fuel ratio between said lower one and said higher one, said fuel injection amount control means sequentially and separately changes said amounts of fuel injected by the respective fuel injection valves from an amount suitable for one of said lower and higher air-fuel ratios to another amount suitable for the other of the lower and higher air-fuel ratios, with predetermined time intervals being provided for the changing operations for the fuel injection valves, said fuel injection amount control means including means for changing said time intervals.
Dependencies are inferred from the claim text.