| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control device which is simply constructed to retain the heat of a catalyst, thus activating the catalyst early at the start time of an engine while suppressing a drop in the temperature of the catalyst at the stop time of the engine.SOLUTION: The exhaust emission control device includes a catalyst 1 for purifying exhaust gas, a casing 2 storing the catalyst 1, an evacuation pipe 3, and a check valve 4 arranged in the evacuation pipe 3. The casing 2 has an inner tube 2i storing the catalyst 1, and an outer tube 2o forming a sealed space 2s outside the inner tube 2i. The evacuation pipe 3 communicates the sealed space 2s with an intake manifold 30. The check valve 4 utilizes a negative pressure in the intake manifold 30 generated with the reciprocation of a piston 21 and the opening/closing of an intake valve 22 when a throttle valve 40 is substantially closed, to permit the distribution of the gas from the internal of the sealed space 2s to the side of the intake manifold 30.SELECTED DRAWING: Figure 1 |
