Patent ID: 7963105
Filing Date: 2011-06-21
Classification: F01N,F02D,F02M,Y02T

Abstract:
1. An exhaust purification system for an internal combustion engine having a common rail in a fuel supply system, comprising: a catalyst interposed in an exhaust path of the internal combustion engine; a fuel pump that supplies fuel to the common rail; an exhaust-side fuel injection valve that is interposed in an exhaust path so as to be located upstream of the catalyst and injects into the exhaust path the fuel supplied from the fuel pump; common rail pressure-detecting means for detecting pressure in the common rail; revolution speed-detecting means for detecting revolution speed of the internal combustion engine; and estimation means for estimating a clogging degree of an injection port of the exhaust-side fuel injection valve during the fuel injection of the exhaust-side fuel injection valve, on the basis of fluctuations in the pressure in the common rail, within a period when the fuel is injected into the exhaust path, which is detected by the common rail pressure-detecting means and fluctuations in the revolution speed of the internal combustion engine, within the period when the fuel is injected into the exhaust path, which is detected by the revolution speed-detecting means.