Patent ID: 7600380

Claim:
A method for directing exhaust gas flow in a two-stage turbocharger for use in a motor vehicle, comprising the steps of: providing a high-pressure turbine; providing at least one outlet formed as a portion of said high-pressure turbine; providing a low-pressure turbine located downstream from said high-pressure turbine; providing an exhaust manifold; providing a first exhaust gas outlet in said exhaust manifold, said first exhaust gas outlet in fluid communication with said high-pressure turbine; providing a second exhaust gas outlet in said exhaust manifold; providing a valve assembly in fluid communication with said exhaust manifold through said second exhaust gas outlet of said exhaust manifold, with said high-pressure turbine, and said low-pressure turbine; providing a valve stem in said valve assembly, said valve stem being operable with a hinge assembly to be pivotable within said valve assembly, and wherein said valve assembly is operably connected to an actuator that selectively moves said hinge assembly and said valve stem; providing a first valve plate connected to said valve stem; providing a second valve plate connected to said valve stem; providing a pin extending through said valve stem, and connected to said first valve plate and said second valve plate; providing an exhaust gas inlet port formed as a portion of said valve assembly, and in fluid communication with said second exhaust gas outlet of said exhaust manifold; providing a high-pressure turbine inlet port formed as a portion of said valve assembly, and in fluid communication with said at least one outlet formed as a portion of said high-pressure turbine; providing a first contact surface formed as part of said high-pressure turbine inlet port; providing a second contact surface formed as part of said exhaust gas inlet port; pivoting said valve stem in said valve assembly such that said first valve plate contacts said first contact surface and selectively blocks said high-pressure turbine inlet port, thereby directing exhaust gas flow from said exhaust manifold through said second exhaust gas outlet, through said exhaust gas inlet port, and through said low-pressure turbine outlet port, and into said low-pressure turbine; and pivoting said valve stem in said valve assembly such that said second valve plate contacts said second contact surface and selectively blocks said exhaust gas inlet port, thereby directing exhaust gas flow from said exhaust manifold through said first exhaust gas outlet, through said high-pressure turbine, said at least one outlet of said high-pressure turbine, through said high-pressure turbine inlet port, and through said low-pressure turbine outlet port into said low-pressure turbine.