EXHAUST GAS CIRCULATION VALVE AND MANUFACTURING METHOD

摘要

A substantially annular ridge composed of a large-diameter part (12) and a small-diameter part (11) is formed on the inner peripheral surface of an exhaust gas passage of a housing (10), and an annular member (20) is press-fitted and secured in the large-diameter part (12). One side (a first valve seat (51)) of a valve seat (50) is configured from the inside edge of the annular member (20), and the other side (a second valve seat (52)) is configured from the edge of an unlevel surface (13). Seat leakage is measured when the annular member (20) is press-fitted, the press-fitting is ended at a position where the amount of leakage is substantially minimal, and a space (S) is left between the unlevel surface (13) and an end surface (21) of the annular member (20).