| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device in which HC separated from an HC adsorption purifying means is purified at a prescribed purification ratio by the HC adsorption purifying means. <P>SOLUTION: The HC adsorption purifying means 14 has a function to adsorb HC when the temperature is low, and to separate and to purify the adsorbed HC when the temperature becomes high, and is arranged to an exhaust gas passage of the exhaust emission control device 20. The exhaust emission control device is provided with a bypass passage 18 to bypass the adsorption purifying means 14; and a flow rate control means 22 for controlling the flow rate of an exhaust gas to circulate the adsorption purifying means 14, by adjusting a ratio of the flow rate of the exhaust gas to circulate the adsorption purifying means 14 and the flow rate of the exhaust gas to flow the bypass passage 18. The exhaust emission control device is provided in which the flow rate of the exhaust gas to circulate the adsorption purifying means 14 is controlled by the flow rate control means 22, so as to be ≤ a predetermined upper limit flow rate for purifying the separated HC by the adsorption purifying means 14 at the prescribed purification ratio. <P>COPYRIGHT: (C)2004,JPO |
