| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust gas flow control valve for an engine which can reduce valve-closing torque applied to the valve plate of a valve spring in accordance with increase of opening degree of the valve plate and moreover, lessens friction of the valve spring and can stabilize opening and closing characteristics of the valve plate.SOLUTION: A valve spring 24 is constituted of a torsion coil spring which includes a coil part 24a and first and second arms 24b, 24c extended from the coil part 24a and exhibits elastic repulsion force in a direction of increasing a setting angle δ between the first and second arms 24b, 24c, the coil part 24a is borne by a valve plate 23 so as to apply valve closing torque to the valve plate 23 by virtue of the elastic repulsion force, at the same time, the first arm 24b is locked to the valve plate 23, and the second arm 24c is connected with a tip end part of a link 25 which is offset to the valve hole 22 side rather than a first fulcrum 29 and is supported turnably at a second fulcrum 30 on a valve seat plate 21 so as to be relatively turnable. |
