Boost device bypass valve

摘要

A wastegate valve for use with turbocharged engines. The wastegate valve vents exhaust gasses upstream of the turbocharger high pressure turbine to reduce turbocharger speed and associated boost pressure. The wastegate valve includes a piston attached to a poppet valve and movable within a housing. The housing receives pressurized intake gasses at a side of the piston to actuate the popper valve between open and closed positions. A diaphragm is sealingly disposed between the piston and housing. The housing includes mechanical stop means to limit the piston travel, thereby reducing flexure of the diaphragm. Additionally, the diaphragm is disposed in the housing in such a way that the diaphragm flexes between reduced peak compressive and tensile stresses.