BUTTERFLY VALVE FOR EXHAUST PIPE AND EXHAUST PIPE STRUCTURE USING THIS BUTTERFLY VALVE

摘要

PURPOSE: To improve heat resistance and lightness by forming a valve plate of ceramics in a butterfly valve disposed at the intermediate part of an exhaust pipe between the exhaust manifold of an internal combustion engine and an exhaust gas purifying catalyst. ;CONSTITUTION: The valve plates 5 of butterfly valves 1, 3 disposed at exhaust pipes 7, 9 between the exhaust manifold of an automobile engine 1 and exhaust gas purifying catalysts 13, 15 are formed of ceramics. The valve plates 5 are formed into elliptic shape so as to close the exhaust pipes 7, 8 at a specified angle α to the axial direction A of the exhaust pipes 7, 9, and the angle αis set into a range of 60-85°. The side face of the valve plate 5 is chamfered, and the radius-of-curvature of this side face is set to about l-5mm. Accordingly, clearances between the valve plates 5 and the exhaust pipes 7, 9 are further reduced, and the leakage of exhaust gas is suppressed more effectively.;COPYRIGHT: (C)1995,JPO