Bypass control apparatus for turbocharged internal-combustion engines

Claim 1

In a bypass control apparatus for turbocharged internal-combustion engines having an opening characteristic, depending upon the engine speed, for a bypass valve located in a bypass pipe which connects a point of a boost air pipe located downstream of a compressor to a point of an exhaust gas pipe located upsteam of a turbine inlet of a turbocharger for the engine, the improvement which comprises: a flow pipe intended to accommodate a fluid stream for flow therethrough and flow communicating with the bypass valve; said fluid stream serving as a work medium for actuation of the bypass valve; fluid source for delivering said fluid stream to said flow pipe; a supply pipe operatively associated with said fluid source means for receiving said fluid stream; a discharge pipe flow communicating with said supply pipe for the outflow of said fluid stream; said flow pipe extending between said supply pipe and said discharge pipe to define a pipe section; a fixedly adjustable throttle valve provided for said pipe section; a spring-loaded control throttle valve provided for said pipe section; electrical signal transducer and amplifier means for operating said spring-loaded control throttle valve as a function of the speed of the engine; proportional electromagnetic means including an armature; a signal line connecting the amplifier with said proportional electromagnetic means; and said armature being rigidly connected with said control throttle valve for controlling operation of said control throttle valve as a function of the speed of the engine.