Patent ID: 8365516

Claim:
An exhaust gas purification apparatus for an internal combustion engine comprising: a first exhaust gas purification unit that has a function to purify NOx; a second exhaust gas purification unit that is arranged in series with the first exhaust gas purification unit, and has a function to collect particulate matter in an exhaust gas; HC supply units that include a first addition valve and a second addition valve and are provided on the first exhaust gas purification unit and the second exhaust gas purification unit, respectively, for supplying HC to the first exhaust gas purification unit and the second exhaust gas purification unit, respectively; and an electronic control unit that includes program logic, which when executed, decides priority between supplying HC to the first exhaust gas purification unit and supplying HC to the second exhaust gas purification unit and decides priority between a supply of HC that forms a reductive atmosphere and a supply of HC that is requested for raising temperature; wherein when a request for supplying HC to the first exhaust gas purification unit and a request for supplying HC to the second purification unit overlap, an amount of HC supplied to a lower priority unit is lower than when the requests for supplying HC do not overlap.