ENGINE

摘要

Provided is an engine which is provided with an EGR device, wherein: an actual intake/exhaust gas pressure ratio π1 of an intake-gas pressure P1 to an exhaust-gas pressure P2 is calculated from the detected exhaust-gas pressure P2 and the detected intake-gas pressure P1; an estimated intake/exhaust gas pressure ratio π2 of the intake-gas pressure P1 to the exhaust-gas pressure P2 is calculated from an engine rotational frequency N, and a fuel injection amount F; and, in cases when the actual intake/exhaust gas pressure ratio π1 is less than a prescribed value π0, an EGR gas weight Megr is calculated based on the actual intake/exhaust gas pressure ratio π1, and in cases when the actual intake/exhaust gas pressure ratio π1 is equal to or more than the prescribed value π0, the EGR gas weight Megr is calculated based on the estimated intake/exhaust gas pressure ratio π2.

主权项

1. An engine comprising an EGR device which flows back a part of exhaust gas to intake air as EGR gas,
characterized in that an actual intake/exhaust pressure ratio of intake pressure concerning exhaust pressure is calculated from detected exhaust pressure P2 and detected intake pressure P1, an estimated intake/exhaust pressure ratio of the intake pressure concerning the exhaust pressure is calculated from an engine rotation speed and a fuel injection amount, and an EGR gas weight is calculated based on the actual intake/exhaust pressure ratio when the actual intake/exhaust pressure ratio is less than a predetermined value, and the EGR gas weight is calculated based on the estimated intake/exhaust pressure ratio when the actual intake/exhaust pressure ratio is not less than the predetermined value.