Bypass valve with valve seat cover for an exhaust turbocharger and exhaust turbocharger with such a bypass valve

摘要

Bypass valve for an exhaust turbocharger having a valve valve cap (51) at one end of a bypass channel and a valve flap (55),where the valve flap roof (51) has a valve seat surface (52) and a vertical fan seat axis (53); andThe valve flap (55) has a valve flap exterior (59) and a closure surface (51) facing the valve flap roof (56) that interacts with the valve seat surface for opening and closing the bypass channel (50),In the closed state of the bypass valve, the closing surface (56) of the valve flap (55) is on the valve seat surface (52) and the valve seat surface (52),via a part of the valve valve exterior (59),in its radial radius, in relation to the valve seat axis (53), above the valve valve outer envelope (59) of the valve flap (55), with a valve seat strap (77) positioned on the outer edge of the valve seat surface (52) of this compartment and outside the valve flap outer envelope (59), which: from the valve seat surface (52),extends mainly in the direction of the valve seat axis (53) and in the opening direction of the valve flap (55) over an axial valve seat belt height (78) and over a part of the valve seat exterior range (54a), so that the seat belt (77) partially covers the outside of the valve flaps (59) and covers the seat belt height (78), characterized by:over a further part of the valve flap exterior (59) the closure surface (56) of the valve flap (55) in its radial periphery, in relation to the valve seat axis (53), in radial direction over a valve seat exterior area (54a) of the valve flap roof (51),where at the outer edge of the closing surface (56) this furthera valve shorter (57) is positioned outside the valve seat outer envelope (54a), which extends from the closing surface (56) mainly in the direction of the valve seat axis (53) over an axial valve shortening height (58) over the valve flap roof (51) and over a part corresponding to the further part of the valve flap outer area (59) of the valve seat outer area (54a); so that the valve cover (57) partially covers the outside of the valve seat (54a) and in an axial overlapping area the valve cover (51) covers the valve cover height (58).