EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine that enables a reduction in fuel consumption while maintaining an NOelimination ratio at a high level.SOLUTION: An exhaust emission control device includes an exhaust purification catalyst disposed downstream of a hydrocarbon supply valve and a fuel supply device for supplying fuel to the hydrocarbon supply valve, and is formed to perform operation control for supplying hydrocarbon from the hydrocarbon supply valve so that the amplitude of a concentration change of the hydrocarbon flowing into the exhaust purification catalyst during operation of an engine becomes an amplitude within a predetermined range and the concentration of the hydrocarbon is in a cycle within a predetermined range. When the operation control is performed, pressure of fuel to be supplied to the hydrocarbon supply valve is set based on total fuel consumption of the consumption of fuel injected from the hydrocarbon supply valve and fuel consumption for eliminating NO.SELECTED DRAWING: Figure 25