Turbocharged internal combustion engine having means for controlling supercharging pressure

Claim 1

An apparatus for pneumatic control of supercharging pressure in a turbocompressed engine of the type including a turbocompressor, turbine of which is supplied through an exhaust of an engine to an exhaust pipe, a compressor which supplies an intake manifold of the engine through a delivery pipe and a butterfly valve positioned downstream of said delivery pipe, a bypass passage which interconnects said exhaust and said exhaust pipe so as to bypass said turbine, and a pneumatic actuator having a closing chamber and an opening chamber and which includes a return spring disposed in said opening chamber, comprising: a dump valve located in said bypass passage and controlled by said pneumatic actuator; first and second parallelly oriented tubes connected to said pneumatic actuator wherein said second tube includes throttling constriction means disposed therein and wherein said spring of the pneumatic actuator opens the dump valve; collection pipe means for collecting the pressure in said delivery pipe upstream of the butterfly valve and downstream of the compressor and transmitting said pressure to said first and second parallel tubes, said first tube leading to the closing chamber of the pneumatic actuator and the second tube leading through said throttling constriction means to the opening chamber of said actuator; pressure valve means for communicating with atmosphere and including a control chamber formed therein; a third tube connecting said opening chamber of said actuator with said pressure valve means and atmosphere; and a fourth tube interconnecting the control chamber of said pressure valve means with said delivery pipe downstream of said butterfly valve wherein said pressure valve means further comprises a second spring calibrated such that an outlet portion of said third tube is closed to atmosphere when the pressure in the control chamber exceeds a predetermined desired value of the supercharging pressure.

Claim 2

An apparatus for pneumatic control of supercharging pressure in a turbocompressed engine of the type including a turbocompressor, turbine of which is supplied through an exhaust of an engine to an exhaust pipe, a compressor which supplies an intake manifold of the engine through a delivery pipe and a butterfly valve positioned downstream of said delivery pipe, a bypass passage which interconnects said exhaust and said exhaust pipe so as to bypass said turbine, and a pneumatic actuator having a closing chamber and an opening chamber and which includes a return spring disposed in said opening chamber, comprising: a dump valve located in said bypass passage and controlled by said pneumatic actuator; first and second parallelly oriented tubes connected to said pneumatic actuator wherein said second tube includes throttling constriction means disposed therein and wherein said spring of the pneumatic actuator opens the dump valve; collection pipe means for collecting the pressure in said delivery pipe upstream of the butterfly valve and downstream of the compressor and transmitting said pressure to said first and second parallel tubes, said first tube leading to the closing chamber of the pneumatic actuator and the second tube leading through said throttling constriction means to the opening chamber of said actuator; pressure valve means for communicating with atmosphere and including a control chamber formed therein; a third tube connecting said opening chamber of said actuator with said pressure valve means and atmosphere; and a fourth tube interconnecting the control chamber of said pressure valve means with said delivery pipe downstream of said butterfly valve wherein said pressure valve means further comprises a second spring calibrated such that an outlet portion of said third tube is closed to atmosphere when the pressure in the control chamber exceeds a predetermined desired value of the supercharging pressure.

Claim 4

An apparatus as claimed in claims 1 or 2, further comprising: a gas pedal: an elastic compensator operatively associated with said gas pedal; a solenoid disposed in said collection pipe connecting said delivery pipe to said first and second tubes which places said first and second tubes in communication with atmosphere in a rest position, while establishing communication between said delivery pipe and said tubes in an excited position; and switch means for energizing said solenoid by the gas pedal through said elastic compensator.