Patent ID: 6338246
Filing Date: 2002-01-15
Classification: F01N,Y10T

Abstract:
An exhaust passage control valve comprising:a housing through which exhaust gases from an engine pass: a valve element mounted on said housing; a valve spring for urging said valve element toward a closing side such that, when an exhaust-gas pressure has exceeded a predetermined value, said exhaust passage control valve is opened, said valve element being constituted into a spiral valve element whose outer circumferential portion is seated onto an annular valve seat portion of said housing such that said exhaust passage control valve is opened and closed by extension and contraction of said valve element in a direction of an axis of spiralling, wherein said valve spring is constituted by a helical torsion spring having a coiled cylindrical body portion, and an arm portion on each end of said coiled cylindrical body portion, and wherein said arm portions are engaged with a pair of spring receiving members so as to be slidable in a longitudinal direction of each of said arm portions, said pair of spring receiving members being provided in those portions of said housing which lie on circumferentially opposite sides of said valve seat portion to thereby urge said valve element through said coiled cylindrical body portion toward the closing side.