초록 ▼

A system for controlling boost pressure at various different altitudes of operation of a turbo charged internal combustion engine includes a wastegate valve, an actuator and a controller. Signals delivered from an engine speed sensor, a boost pressure transducer and a barometric pressure sensor are

A system for controlling boost pressure at various different altitudes of operation of a turbo charged internal combustion engine includes a wastegate valve, an actuator and a controller. Signals delivered from an engine speed sensor, a boost pressure transducer and a barometric pressure sensor are processed in the controller. A control signal delivered from the controller to the actuator controls the position of the wastegate valve, bypass of exhaust gasses and the speed of the turbocharger.

대표청구항 ▼

[ I claim:] [1.] A control system, for controlling turbocharger boost pressure of an internal combustion engine at various different altitudes, said engine having an intake manifold and an exhaust manifold respectively connected to a compressor section and a turbine section of a turbocharger, compri

[ I claim:] [1.] A control system, for controlling turbocharger boost pressure of an internal combustion engine at various different altitudes, said engine having an intake manifold and an exhaust manifold respectively connected to a compressor section and a turbine section of a turbocharger, comprising:a wastegate valve connected between said exhaust manifold and said turbine section, said wastegate valve being movable between an open position at which fluid flow exhausted by the engine is free to bypass the turbine and a closed position at which fluid flow exhausted by the engine is restricted from bypassing the turbine;first means for sensing a speed of the engine and delivering a responsive speed signal;second means for sensing a boost pressure of the engine and delivering a responsive boost signal;third means for sensing a rack position of the engine and delivering a responsive rack position signal;fourth means for sensing a barometric pressure and delivering a responsive barometric pressure signal;control means connected to said first, second, third and fourth sensing means for receiving said speed, boost, rack position and barometric pressure signals, determining a boost error based on actual and target boost values for said speed, boost, rack position and barometric pressure signals, and delivering a responsive control signal;actuator means for receiving said control signal, responsively moving said wastegate valve toward one of the open and closed positions, and to a position between the open and closed positions;said actuator means including:a linear actuator having a housing and a rod connected to the wastegate valve and slidably connected to said housing, said housing having first and second ends, said linear actuator having a diaphragm connected to said rod and said housing at a location between said first and second housing ends, said diaphragm defining a chamber in said housing, said rod being movable in response to said proportional valve delivering pressurized fluid flow to said chamber, said first end having an opening of a preselected diameter therein, said rod having a preselected diameter and extending through the opening, said diameter of the rod being smaller than the diameter of the opening and defining a predetermined clearance therebetween, said predetermined clearance defining a controlled leakage path between the chamber and the atmosphere; anda proportional valve connected to said housing, said control means and a source of pressurized fluid flow, said proportional valve receiving said control signal and responsively controlling the pressure of the fluid flow delivered from the source of pressurized fluid flow to the housing, said linear rod being movable relative to the housing in response the fluid pressure to move the wastegate valve to said open and closed positions.