To provide an exhaust gas purifier of an internal combustion engine, achieving the optimal exhaust gas performance by selecting the selector valve at the optimal timing according to the actual activation state of a catalyst device.
This exhaust gas purifier comprises the catalyst device 6 provided with an exhaust system 2 of the internal combustion engine, an absorbing material 16 provided to a second channel 14 bypassing a first channel 13 of the exhaust system 2, absorbing hydrocarbon in the exhaust gas, the selector valve 15 that can select between the open position for opening the first channel and the close position for closing it, a start time temperature state detection means 25 detecting temperature state TCAT_INI of the exhaust system 2 at the time of starting, an after-start exhaust heat quantity calculating means 25 calculating heat quantity SGM_Q of the exhaust gas discharged after starting, and selector valve driving means 19, 25 driving the selector valve 15 in the close position and driving it in the opening position according to the start time temperature state and the after-star exhaust heat quantity of the exhaust system 2.
SATO TADASHI
TAKAKURA SHIRO
MIYAHARA YASUYUKI
