Fuel injection controller for internal combustion engine

A fuel injection controller for an internal combustion engine that is applied to an accumulator type fuel injection system including an accumulation container for accumulating and holding high-pressure fuel, a fuel pump for pressure-feeding fuel to the accumulation container, and a fuel injector that is disposed in each cylinder of a multi-cylinder internal combustion engine and injects the high-pressure fuel accumulated in the accumulation container, the fuel injection controller comprising:

• injection cylinder pressure detecting means that sequentially detects a first fuel pressure varied when the fuel injector injects the fuel in an injection cylinder;
• non-injection cylinder pressure detecting means that sequentially detects a second fuel pressure having no variation or a little variation caused when the fuel injector injects the fuel in a non-injection cylinder that is not the injection cylinder;
• and
• injection characteristic computing means that computes an injection characteristic of the fuel injector on the basis of pressure variation data that is a difference between the first fuel pressure detected by the injection cylinder pressure detecting means and the second fuel pressure detected by the non-injection cylinder pressure detecting means, wherein
• the first fuel pressure and the second fuel pressure are concurrently detected.

A method of controlling fuel injection for an internal combustion engine that is applied to an accumulator type fuel injection system including an accumulation container for accumulating and holding high-pressure fuel, a fuel pump for pressure-feeding a fuel to the accumulation container, and fuel injectors for injecting the high-pressure fuel accumulated in the accumulation container, the method comprising:

• sequentially detecting a first fuel pressure varied when the fuel injector injects the fuel;
• sequentially detecting a second fuel pressure varied when the fuel pump pressure-feeds the fuel;
• correcting the first fuel pressure based on the second fuel pressure that is detected concurrently with the first fuel pressure when the fuel injector injects the fuel, thereby computing an injection pressure;
• and
• computing an injection characteristic by the fuel injector on the basis of the computed injection pressure, wherein
• the first fuel pressure is detected downstream of a fuel outlet of the accumulation container in a fuel passage from the accumulation container to an injection port of the fuel injector, and
• the second fuel pressure is detected downstream of the fuel outlet of the accumulation container in a fuel passage from the accumulation container to an injection port of another fuel injector.

A method of controlling fuel injection for an internal combustion engine that is applied to an accumulator type fuel injection system including an accumulation container for accumulating and holding high-pressure fuel, a fuel pump for pressure-feeding fuel to the accumulation container, and a fuel injector that is disposed in each cylinder of a multi-cylinder internal combustion engine and injects the high-pressure fuel accumulated in the accumulation container, the method comprising:

• sequentially detecting a first fuel pressure varied when the fuel injector injects the fuel in an injection cylinder;
• sequentially detecting a second fuel pressure having no variation or a little variation caused when the fuel injector injects the fuel in a non-injection cylinder that is not the injection cylinder;
• and
• computing an injection characteristic of the fuel injector on the basis of pressure variation data that is a difference between the first fuel pressure and the second fuel pressure, wherein
• the first fuel pressure and the second fuel pressure are concurrently detected.