US Patent No. 10,364,716

EXHAUST GAS CONTROL APPARATUS FOR INTERNAL COMBUSTION ENGINE AND EXHAUST GAS CONTROL METHOD FOR INTERNAL COMBUSTION ENGINE


Patent No. 10,364,716
Issue Date July 30, 2019
Title Exhaust Gas Control Apparatus For Internal Combustion Engine And Exhaust Gas Control Method For Internal Combustion Engine
Inventorship Naoya Kaneko, Gotemba (JP)
Takayuki Ohtsuka, Susono (JP)
Assignee Toyota Jidosha Kabushiki Kaisha, Toyota-shi Aichi-ken (JP)

Claim of US Patent No. 10,364,716

1. An exhaust gas control apparatus for an internal combustion engine, the exhaust gas control apparatus comprising:a first catalyst provided in an exhaust passage of the internal combustion engine, the first catalyst having an oxidation ability and an oxygen storage ability;
a filter provided in the exhaust passage downstream of the first catalyst and configured to trap particulate matters in exhaust gas, the filter supporting a second catalyst that is a catalyst having an oxidation ability and an oxygen storage ability; and
an electronic control unit configured to, in a case of regenerating the filter at a time of a start of the internal combustion engine, execute first control for increasing a temperature of the first catalyst to a predetermined temperature, wherein:
the electronic control unit is configured to execute second control after the first control;
the second control is control for alternately executing lean control and rich control multiple times;
the lean control is control for, over a period longer than a period from when a target air-fuel ratio of the internal combustion engine is set to a predetermined lean air-fuel ratio that is an air-fuel ratio greater than a stoichiometric air-fuel ratio until an air-fuel ratio of exhaust gas flowing out from the first catalyst becomes greater than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined lean air-fuel ratio; and
the rich control is control for, over a period longer than a period from when the target air-fuel ratio is set to a predetermined rich air-fuel ratio that is an air-fuel ratio smaller than the stoichiometric air-fuel ratio until the air-fuel ratio of exhaust gas flowing out from the first catalyst becomes smaller than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined rich air-fuel ratio.