EXHAUST GAS PURIFICATION SYSTEM FOR INTERNAL COMBUSTION ENGINE Russian patent published in 2017 - IPC F02D41/02 

FIELD: engine devices and pumps.

SUBSTANCE: exhaust gas purification system comprises an exhaust gas purifying catalyst 20, an air-fuel ratio sensor 41 from an outlet side, and a control device performing control of air-fuel ratio to control air-fuel ratio of exhaust gas and control fault diagnostics for diagnostics of air-fuel ratio sensor from outlet side. When controlling air-fuel ratio, the control device alternately and periodically switches air-fuel ratio of exhaust gas flowing in exhaust gas purification catalyst, between rich air-fuel ratio and lean air-fuel ratio. When performing control of the fault diagnostics, the control device evaluates that the sensor of the air-fuel ratio from the outlet side has become defective, when by means of air-fuel ratio control, the air-fuel ratio of exhaust gas is made rich in air-fuel ratio, and outlet air-fuel ratio of air-fuel ratio sensor from outlet side changes from air-fuel ratio which is richer than the predetermined lean air-fuel ratio to lean air-fuel ratio.

EFFECT: generating the exhaust gas purification system for internal combustion engine which is capable to provide fault diagnostics when the air-fuel ratio sensor from the outlet side has a fault in the form of cracked element.

8 cl, 18 dwg