| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the occurrence of abnormality of a VVT (a variable valve timing control mechanism) due to lodging of a foreign matter in an OCV (an oil pressure control valve). SOLUTION: When pedalling of an accelerator pedal is not effected during operation of a VVT 11 and an idle switch 4 is turned ON and the number of revolutions of an engine is within a given range, cleaning operation of an OCVT 10 is executed. In this case, the OCV 10 is charged alternately with a maximum current and a minimum current and only the given number of revolutions is widely fluctuated in a given time so that a displacement amount of the linear solenoid of the OCV 10 is increased to a maximum and decreased to a minimum. In this way, discharge for removal is effected before the number of revolutions of an engine is reduced to the number of idle revolutions even when lodging of a foreign matter in the OCV 10 occurs. This constitution prevents the occurrence of abnormality of the VVT 11 and especially stabilizes the number of idle revolutions right after an internal combustion engine 1 is brought into idle operation.</p> |
