| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide "an acquisition method for an alcohol concentration-corresponding value" capable of precisely acquiring the value corresponding to a fuel alcohol concentration early without being affected by the fluctuation of a combustion state after the start of an engine. <P>SOLUTION: The device includes the following means for: acquiring cylinder pressure P (θa) at prescribed timing (BTDCθadeg) within a period from the start of a compression stroke to before that of mixed gas combustion based on the output of a cylinder pressure sensor (step 620); calculating gas internal energy U (θa) at prescribed timing based on the product of the cylinder pressure P (θa) with the inner volume of a combustion chamber V (θa) at the prescribed timing (step 630); and then acquiring the actual fuel alcohol concentration according to such a relation that the higher the internal energy U (θa) becomes, the lower the fuel alcohol concentration becomes (step 640). <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
