Turbocharger control and method

In combination with an internal combustion engine having and intake manifold and a throttle positionable to vary power developed by the engine, a turbocharger driven by flow of exhaust gases from the engine and operable to deliver gas flow to said intake manifold, and apparatus, for controlling operation of said turbocharger comprising:

• a member exposed to said exhaust gas flow and movable to regulate exhaust gas flow through said turbocharger to control speed of the latter, the pressure of said exhaust gas flow exerting a first force on said member urging the latter in a direction decreasing said turbocharger speed;
• first sensing means for sensing throttle position;
• means responsive to said first sensing means and operably associated with said member for exerting a second force thereon opposing said first force of exhaust gas pressure and urging said member in a direction increasing turbocharger speed;
• an element engageable with said member;
• second sensing means for sensing intake manifold pressure;
• and
• means responsive to said second sensing means and operably associated with said element for exerting a third force thereon in relation to intake manifold pressure urging said element to engage said member to move the latter in said direction decreasing turbocharger speed.

In combination with an internal combustion engine having an intake manifold, and exhaust manifold, a turbocharger delivering gas flow to said intake manifold, and a throttle positionable to vary power developed by the engine, said turbocharger being driven by exhaust gas flow from the engine, apparatus for controlling exhaust manifold pressure comprising:

• a member exposed to said exhaust gas flow whereby the pressure of said exhaust gas exerts a first force on said member urging the latter toward an open position diverting exhaust gas flow from said turbocharger to thereby reduce its speed and reduce exhaust manifold pressure;
• means operably associated with said intake manifold and said member for exerting a second force on said member in relation to intake manifold pressure urging said member toward said open position;
• biasing means operably associated with said second force means for exerting a biasing force opposing said second force without acting upon said member;
• and
• means operably associated with said throttle and said member for exerting a third force on said member in relation to throttle position, said third force urging said member toward a closed position to increase turbocharger speed and intake manifold pressure, whereby at throttle positions requiring higher power from the engine said third force opposes said first and second forces in moving said member, while at partial throttle positions requiring lesser engine power said first force overcomes said third force to move said member to reduce exhaust manifold pressure.

A method of controlling a waste gate valve operable to vary speed of a turbocharger delivering gas flow to the intake manifold of an internal combustion engine having a throttle positionable to vary power developed by the engine, said turbocharger being driven by exhaust gas flow from the engine and said valve operable to vary said flow to said turbocharger;

• comprising the steps of:
• urging said valve toward an open position reducing turbocharger speed by a first force developed by pressure of sid exhaust gas flow;
• producing a second force on said valve in relation to the position of said throttle, said second force urging said valve toward a closed position increasing turbocharger speed;
• producing a third force on said valve in relation to intake manifold pressure, said third force urging said valve toward said open position;
• and
• producing a biasing force opposing said third force without acting upon said valve, whereby said third force overcomes substantially only said biasing force to move said valve to its open position while said first force overcomes substantially only said second force to move said valve to its open position.

A method of controlling speed of operation of a turbocharger delivering gas flow to the intake manifold of an internal combustion engine having a throttle positionable to vary torque developed by the engine, said turbocharger being driven by exhaust gas flow from the engine;

• comprising the steps of:
• sensing throttle position, intake manifold pressure, and exhaust manifold pressure;
• controlling turbocharger speed in relation to said sensed intake manifold pressure whenever said throttle is at substantially full throttle position requiring substantially maximum torque from said engine;
• and
• controlling turbocharger speed in relation to said sensed exhaust manifold pressure whenever said throttle is at part throttle position.