EXHAUST GAS PURIFYING DEVICE OF CYLINDER INJECTION INTERNAL COMBUSTION ENGINE

摘要

The present invention relates to an exhaust purifying apparatus for an in-cylinder injection type internal combustion engine and causes exhaust gas temperature to rise reliably, thereby desorbing reliably a sulfur component (SOx) adhered to an NOx catalyst and enhancing the durability of the NOx catalyst. For this reason, the exhaust purifying apparatus for an in-cylinder injection type internal combustion engine comprises an NOx catalyst (9A) for adhering NOx to itself in an oxygen concentration excess condition and desorbing NOx in an oxygen concentration reduction condition, and sulfur component desorption means (107) for desorbing a sulfur component from the NOx catalyst (9A). The sulfur component desorption means (107) injects additional fuel during an expansion stroke in addition to main injection and burns the additional fuel again so that exhaust gas temperature is raised to a predetermined temperature or beyond, whereby the sulfur component is desorbed. <IMAGE>