Patent ID: 8798893
Filing Date: 2014-08-05
Classification: F02D

Abstract:
1. A fuel injection control apparatus for an internal combustion engine, comprising: a fuel injection amount control section that increases a fuel injection amount by a larger one of an OTP boost value of an OTP boosting and a power boost value of a power boosting when both of an OTP boosting execution condition and a power boosting execution condition are met, in which the OTP boosting execution condition is an execution condition for the OTP boosting that increases the fuel injection amount in order to prevent overheating of an exhaust gas catalytic converter, and the power boosting execution condition is an execution condition for the power boosting that increases the fuel injection amount in order to set air-fuel ratio of mixture to output air-fuel ratio; a convergence temperature estimation section that estimates a convergence temperature of the exhaust gas catalytic converter on the assumption that an operating condition of the internal combustion engine is in a normal operating condition by correcting a reference convergence temperature, which is calculated in accordance with engine speed and engine load, based on a temperature decrement quantity of the exhaust gas catalytic converter which is caused by at least the power boosting; an ordinary temperature estimation section that estimates an ordinary temperature that is a current temperature of the exhaust gas catalytic converter on the assumption that an operating condition of the internal combustion engine is in a normal operating condition, in accordance with the convergence temperature; an OTP boost correction value calculation section that calculates an OTP boost correction value, which is the OTP boost value on the assumption that temperature of the exhaust gas catalytic converter is the ordinary temperature, by correcting an OTP boost reference value, which is the OTP boost value on the assumption that the temperature of the exhaust gas catalytic converter is the convergence temperature, in accordance with the ordinary temperature and the convergence temperature; and an OTP boost value determination section that selects either of the OTP boost reference value or the OTP boost correction value as the OTP boost value when the OTP boosting is performed, wherein when both of the OTP boosting execution condition and the power boosting execution condition are met, the convergence temperature estimation section estimates the convergence temperature on the assumption that the temperature decrement quantity of the exhaust gas catalytic converter which is caused by the power boosting is zero.