Wastegate valve

Abstract

A wastegate valve for a bypass path for a turbocharger in an internal combustion engine, the wastegate valve com- prises a valve scat defining a plane which is non-orthogonal to the principal flow axis for gases flowing along the bypass path and a valve member pivotable from an open position to a closed position, wherein in the closed position the valve member is seated on the valve seat, and in a frilly open position the valve member is positioned to direct gases exiting the bypass path onto a leading face of a catalytic converter monolith for heating the monolith.

1 - 17 . (canceled) 
     
     
         18 . An exhaust system for an internal combustion engine, comprising:
 a turbocharger having a turbine,   a bypass path arranged to allow exhaust gas to bypass the turbine,   a chamber, and   a catalytic converter,
 wherein the bypass path is selectively openable and closable by a wastegate valve element to allow or prevent exhaust gas flowing from the engine to bypass the turbocharger and thereby enter the chamber wherein the wastegate valve element is seated in the closed condition on a valve seat and when the wastegate valve is open exhaust gas exiting the turbine is directed by the wastegate valve element along the chamber to impinge upon a leading face of the catalytic converter. 
   
     
     
         19 . An exhaust system as claimed in  claim 18 , wherein the valve seat defines a plane that is non-orthogonal to a principal flow axis for gases flowing along the bypass path. 
     
     
         20 . An exhaust system as claimed in  claim 19 , wherein the valve member is pivotable, at its fully open position, to an angle with respect to the plane defined by the valve seat, wherein the angle is from 30° to 70°. 
     
     
         21 . An exhaust system as claimed in  claim 20 , wherein the angle is from 35° to 65°. 
     
     
         22 . An exhaust system as claimed in  claim 21 , wherein the angle is from 36° to 63°. 
     
     
         23 . An exhaust system as claimed in  claim 20 , wherein the angle is from 40° to 60°. 
     
     
         24 . An exhaust system as claimed in  claim 20 , wherein the angle is from 40° to 50°. 
     
     
         25 . A exhaust system as claimed in  claim 18 , wherein the valve member is pivotable, at its fully open position, to an angle of 0° to 60°, with respect to a principal flow axis along the bypass path. 
     
     
         26 . An exhaust system as claimed in  claim 25 , wherein the valve member is pivotable to an angle of 45° to 60° to the principal flow axis along the bypass path. 
     
     
         27 . An exhaust system as claimed in  claim 18 , wherein the bypass path is provided, at least in part, by a conduit, the valve seat being provided on a distal end of the conduit. 
     
     
         28 . An exhaust system as claimed in  claim 27 , wherein the bypass path is arranged to protrude into a chamber downstream thereof. 
     
     
         29 . An exhaust system as claimed in  claim 18 , wherein the valve member pivots into and/or towards the center of the chamber downstream of the bypass path. 
     
     
         30 . An exhaust system as claimed in  claim 18 , wherein at least some gases exiting the bypass path exhaust along a flow path which is inclined at an angle to a principal flow path axis along the chamber. 
     
     
         31 . An exhaust system according to  claim 18 , wherein the plane defined by the valve seat at the end of bypass path is at an angle to a principal flow axis along the bypass path, wherein the angle is less than 90°. 
     
     
         32 . An exhaust system according to  claim 31 , wherein the angle is between 90° and 45°. 
     
     
         33 . An exhaust system according to  claim 32 , wherein the angle is between 50° and 85°. 
     
     
         34 . An exhaust system according to  claim 33 , wherein the angle is between 55° and 80°. 
     
     
         35 . An exhaust system according to  claim 34 , wherein the angle is between 60° and 75°. 
     
     
         36 . An exhaust system according to  claim 35 , wherein the angle is between 60° and 70°. 
     
     
         37 . An exhaust system according to  claim 18 , comprising an actuator to open and close the wastegate valve element, wherein the actuator is selected from an electric actuator, a vacuum actuator and a mechanical actuator. 
     
     
         38 . An exhaust system according to  claim 18 , wherein a plane defined by the valve seat is non-parallel to a leading face of a monolith of the catalytic converter. 
     
     
         39 . An exhaust system as claimed in  claim 18 , wherein the turbocharger is a twin scroll turbocharger. 
     
     
         40 . A method of heating a catalytic converter of an engine to an effective temperature, for example during a start-up phase of the engine, the method comprising
 causing at least some gases from the engine to bypass a turbocharger turbine along a bypass path, and   directing the gases exiting the bypass path onto a leading face of a monolith of the catalytic converter.   
     
     
         41 . A method as claimed in  claim 40 , further comprising directing the gases exiting a turbine of the turbocharger onto a leading face of the monolith of the catalytic converter. 
     
     
         42 . A method as claimed in  claim 41 , wherein the turbocharger is a twin-scroll turbocharger. 
     
     
         43 . A method as claimed in  claim 40 , wherein the turbocharger is a twin-scroll turbocharger.