| 摘要 |
PROBLEM TO BE SOLVED: To obtain an exhaust circulation control valve with a simple structure which has both a small flow amount control characteristics with high accuracy and a large flow amount control characteristics with satisfactory responsiveness. SOLUTION: An exhaust circulation control valve 1 has an exhaust gas take-in port 6 for taking in the exhaust gas from an exhaust gas passage 2 of an engine E, and an exhaust gas supply port 7 for supplying the exhaust gas to an intake passage 3 of the engine E. The exhaust gas take-in port 6 communicates with the supply port 7 through first and second openings 11, 12 which are coaxially formed. The openings 11, 12 are respectively provided with first and second valve bodies 15, 16 for opening and closing themselves. The first valve body 15 is controlled according to an operation condition of the engine E by means of a driving mechanism 17. The second valve body 16 is kept close by means of a spring 19. In the case that a lifting rate of the first valve body 15 is increased from a small state, thereby driving the second valve body 16. The exhaust gas flows through the first and second openings 11, 12. |
