摘要 |
<P>PROBLEM TO BE SOLVED: To prevent decrease in catalyst temperature in coasting travel for a long period of time. <P>SOLUTION: After coasting travel is determined (S11), ignition cut is executed at a predetermined timing (S14). A throttle valve 10 is opened to introduce fresh air, and scavenging is performed with un-fuel air-fuel mixture of the fresh air and the fuel injected from an injector 12 in a range directly upstream of a catalyst 7 (S15 to S16). Thereafter, the throttle valve 10 is fully closed (S18), the fuel cut is executed (S19), an EGR valve 23 is opened at a determined opening (S20), and the un-fuel air-fuel mixture is returned to an intake system and circulated. When the coasting travel is continued for a long period of time, and when a temperature of the catalyst 7 is decreased, the throttle valve 10 is slightly opened, a slight amount of fuel is injected from the injector 12 so that the surplus un-fuel air-fuel mixture flows to the catalyst 7, and the catalyst 7 is heated and raised in temperature by oxidation reaction heat. <P>COPYRIGHT: (C)2013,JPO&INPIT |