By-pass valve apparatus of an exhaust turbocharger for an internal combustion engine

A by-pass valve apparatus of an exhaust turbocharger for an internal combustion engine including a compressor having a housing with a through passage and an inlet and an outlet, the compressor being inserted into an intake air conduit of the engine, a turbine inserted into an exhaust conduit of the engine, means for connecting the turbine to the compressor whereby the turbine is driven by exhaust gas from the engine and drives the compressor, and a by-pass conduit selectively connected to the exhaust conduit upstream of the turbine, the by-pass conduit by-passing the turbine to waste the exhaust gas therethrough, the by-pass valve apparatus being provided to selectively open and close the by-pass conduit and comprising in combination:

• a pressure probe for detecting the total pressure of the intake air flow downstream of the compressor;
• a diaphragm device having a diaphragm which defines first and second chambers, the first chamber being in communication with the pressure probe and supplied with the total pressure detected by the pressure probe, the second chamber being in communication with atmospheric pressure;
• and
• a by-pass valve having a valve element inserted into the by-pass conduit, and a valve stem, one end of which is connected to the valve element and another end with the diaphragm.