| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fuel property acquisition device for an internal combustion engine capable of accurately acquiring fuel properties in the steady operating state of the internal combustion engine. <P>SOLUTION: This device is applied to the internal combustion engine provided with a dual injection system equipped with a cylinder injection valve and a port injection valve for every cylinder. When the engine is in the steady operating state, the device fixes a cylinder injection rate R (=fic/(fic+fip)) forcibly to "0" only for a predetermined period tA while maintaining a total injection quantity sumfi (port injection quantity fip + cylinder injection quantity fic) to a basic fuel injection quantity (a fuel quantity for making an exhaust air-fuel ratio abyf coincide with a target air-fuel ratio stoichiometry), then changes the cylinder injection rate R forcibly to "1", and acquires the degree of heaviness Kh of fuel (fuel properties) utilizing that the degree of turbulence of the exhaust air-fuel ratio abyf (an air-fuel ratio deviation area SA) occurring immediately after changing the cylinder injection rate R to "1" depends on the degree of heaviness of fuel. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
