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 can reduce inflow amount of unburned HC to an upstream side catalyst, can promote combustion of the unburned HC and can prevent blocking of an upstream side catalyst carrier surface.SOLUTION: An exhaust emission control device for an internal combustion engine includes: a first catalyst 23 arranged in an exhaust passage 3 of the internal combustion engine 1 to purify exhaust gas; a second catalyst 24 arranged on the downstream side in the exhaust direction from the first catalyst 23 to purify exhaust gas; temperature rise means 15 for raising a temperature of the second catalyst 24 by injecting fuel to combustion gas when determination that a regeneration processing operation of the second catalyst 24 is necessary is made; pressure difference detection means 29 for detecting a pressure difference between an inlet and an outlet of the first catalyst 23; and control means 9 for controlling the operation of the temperature rise means 15. The control means 9 controls operating timing of the temperature rise means 15 on the basis of the detection result obtained by the pressure difference detection means 29.SELECTED DRAWING: Figure 1