METHOD AND APPARATUS FOR CONTROLLING INTERNAL-COMBUSTION ENGINE

摘要

A method for controlling an internal-combustion engine includes detecting knocking in the internal-combustion engine. An EGR gas quantity of EGR gas is increased in a case where the knocking is detected. A part of exhaust gas is circulated into an intake passage as the EGR gas. A fuel octane number of fuel supplied to a cylinder is increased in the case. The fuel octane number is decreased after the fuel octane number has been increased. The EGR gas quantity is maintained so as to prevent the knocking after the EGR gas quantity has been increased.

主权项

1. A method for controlling an internal-combustion engine, the internal-combustion engine including an EGR system capable of recirculating part of exhaust gas into an intake passage as EGR gas and changing an EGR gas quantity supplied to a cylinder, the internal-combustion engine capable of changing a fuel octane number representing an octane number of fuel supplied into the cylinder, the method comprising:
a first step of detecting knocking of the internal-combustion engine; a second step of performing augmenting control that increases the EGR gas quantity via the EGR system and increases the fuel octane number if knocking of the internal-combustion engine is detected in the first step; a third step of decreasing the fuel octane number increased through the augmenting control after the augmenting control begins; and a fourth step of maintaining the EGR gas quantity at a level capable of preventing the knocking of the internal-combustion engine via the EGR system after the augmenting control is performed.