Controller for internal combustion engine

A controller for an internal combustion engine applied to a system in which a main fuel including alcohol and an auxiliary fuel of which volatility is higher than the main fuel can be supplied, the controller comprising:

• an alcohol concentration obtaining means for detecting or estimating the alcohol concentration of the main fuel;
• a coolant temperature sensor detecting a coolant temperature of the internal combustion engine;
• and
• an auxiliary fuel supply control means for controlling an auxiliary fuel supply based on the coolant temperature detected by the coolant temperature sensor and alcohol concentration of the main fuel detected or estimated by the alcohol concentration obtaining means;
• wherein
• in a case that the coolant temperature sensor is abnormal, the auxiliary fuel supply control means conducts the auxiliary fuel supply when the alcohol concentration of the main fuel detected or estimated by the alcohol concentration obtaining means is greater than or equal to an auxiliary fuel supply determination value.

A controller for an internal combustion engine applied to a system in which a main fuel including alcohol can be supplied, the controller comprising:

• an alcohol concentration obtaining means for detecting or estimating the alcohol concentration of the main fuel;
• a coolant temperature sensor detecting a coolant temperature of the internal combustion engine;
• a fuel injection control means for controlling a main fuel injection quantity based on the coolant temperature and the alcohol concentration;
• and
• a pseudo coolant temperature setting means for setting a pseudo coolant temperature which is lower than a standard coolant temperature in a case that the coolant temperature sensor is abnormal, wherein
• the pseudo coolant temperature setting means sets the pseudo coolant temperature in a manner that the pseudo coolant temperature decreases as the alcohol concentration becomes high,
• the fuel injection control means controls the fuel injection quantity of the main fuel by use of pseudo coolant temperature instead of the coolant temperature detected by the coolant temperature sensor in a case that the coolant temperature sensor is abnormal.

A controller for an internal combustion engine applied to a system in which a main fuel including alcohol can be supplied, the controller comprising:

• an alcohol concentration obtaining means for detecting or estimating the alcohol concentration of the main fuel;
• a coolant temperature sensor detecting a coolant temperature of the internal combustion engine;
• a fuel injection control means for controlling a main fuel injection quantity based on the coolant temperature and the alcohol concentration;
• and
• a pseudo coolant temperature setting means for setting a pseudo coolant temperature which is lower than a standard coolant temperature in a case that the coolant temperature sensor is abnormal, and
• an exhaust gas sensor detecting an air-fuel ratio or rich/lean of the exhaust gas, wherein
• the fuel injection control means controls the fuel injection quantity of the main fuel by use of pseudo coolant temperature instead of the coolant temperature detected by the coolant temperature sensor in a case that the coolant temperature sensor is abnormal,
• the fuel injection control means executes an air-fuel ratio feedback control in which a fuel injection quantity of the main fuel is feedback controlled based on an output of the exhaust gas sensor, and
• the pseudo coolant temperature setting means sets the pseudo coolant temperature to a standard coolant temperature or high temperature side when the coolant temperature sensor becomes abnormal during the air-fuel ratio feedback control.