Controller for internal combustion engine

摘要

A multicylinder engine is provided with a fuel injector for each cylinder. An ECU defines a fuel injection condition of the fuel injector based on an engine driving condition and executes a fuel injection control for each cylinder based on the defined fuel injection condition. The ECU computes an engine speed with respect to each cylinder. While the engine is running, the fuel injection condition is operated in an operation cylinder. A fuel property is determined based on the engine speed of the operation cylinder and an engine speed of a non-operation cylinder.

主权项

1. A controller for an internal combustion engine applied to a fuel injection system in which a fuel injector injects fuel into each cylinder of a multicylinder engine, the controller defining a fuel injection condition of the fuel injector based on a driving condition of the engine, the controller executing a fuel injection control based on the defined injection condition with respect to each cylinder, the controller comprising:
a computing unit configured to compute an engine speed, which varies according to a fuel combustion, with respect to each cylinder; an operating unit configured to operate the fuel injection condition in an operation cylinder, which is a part of the cylinders, in such a manner as to be different from the fuel injection condition in a non-operation cylinder other than the operation cylinder while the engine is running; and a determining unit configured to determine a cetane value, when the operating unit operates the fuel injection condition, based on an engine speed computed by the computing unit with respect to the operation cylinder and an engine speed computed by the computing unit with respect to the non-operation cylinder, wherein the determining unit comprises: a first comparing unit configured to compare the engine speed or a cylinder torque of the operation cylinder with the engine speed or the cylinder torque of the non-operation cylinder in operating the fuel injection condition; and a second comparing unit configured to compare the engine speed or a cylinder torque of the operation cylinder with the engine speed or the cylinder torque of the non-operation cylinder before operating the fuel injection condition, and the determining unit determines the cetane value based on a comparison result generated by the first comparing unit and a comparison result generated by the second comparing unit.