EXHAUST CONTROL VALVE

PROBLEM TO BE SOLVED: To achieve simplification of structure and weight reduction of an exhaust control valve. SOLUTION: In the exhaust control valve, an axial end of a coil spring 42 fitted onto an exhaust pipe 35 is fixed to an outer periphery of the exhaust pipe 35. A plate-shaped valve element 41 fixed to the other axial end is biased by tensile force of the coil spring 43 in a direction of seating on a valve seat 35a formed at an exhaust gas outflow opening of the exhaust pipe 35. This arrangement makes it possible to simplify the structure and reduce the weight as compared with a conventional structure in which a valve element is connected to an exhaust pipe through a coil spring generating compressive force. The valve element 41 can therefore move quickly following a pressure change of exhaust gas and operation responsibility of the exhaust control valve 36 is enhanced. As the coil spring 43 serves as a guide when the valve element 41 separates from the valve seat 35a, a position of the valve element 41 can be regulated without providing an extra guide means and the weight can be further reduced by no provision of the guide means. COPYRIGHT: (C)2008,JPO&INPIT