To favorably prevent a fire failure and a torque change from occurring when fuel of exhaust air is enriched, in a vehicle provided with an LPLEGR device.
An ECU 100 of an engine system 10 provided with an LPLEGR 500 conducts LPLEGR control in a rich spike. In the above control, the rich spike is conducted by adding fuel by a fuel adding valve 220. The ECU 100 sets a target intake air volume Gatg so that the oxygen concentration of the intake air before and after the rich spike is conducted becomes steady based on an air-fuel ratio AFsens detected by an air-fuel ratio sensor 221. Once the target intake air volume Gatg is set, drive control of an LPLEGR valve 530 is started according to the target intake air volume Gatg when the control is started with taking the delay in motion of the LPLEGR valve 530 into consideration. At that time, the control starting time is calculated based on the cycle number of an engine 200.
KANTO YUJI
| JP2001234772A | 2001-08-31 | |||
| JPH08144867A | 1996-06-04 |
Koji Yamamoto
Satoshi Nakamura
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