Method and apparatus for starting an engine having a turbocharger

Abstract

A system ( 40 ) for starting an internal combustion engine ( 12 ) of an automotive vehicle ( 10 ) has a controller ( 54 ) coupled to a starter/alternator ( 42 ). The engine ( 12 ) has a crankshaft ( 50 ) and a turbocharger ( 24 ). The controller ( 54 ) initiates the starting of the engine ( 12 ) by rotating the crankshaft ( 50 ). The rotating crankshaft ( 50 ) displaces an amount of air from the cylinders ( 14 ) of the engine ( 12 ) to rotate the rotor shaft of the turbocharger ( 21 ). The turbocharger ( 25 ) thus draws in air, compresses the air and provides the compressed air to the cylinders ( 14 ). When the engine is started the initial power is increased due to the compressed air.

What is claimed is:  
     
       1. A method of controlling the starting of an internal combustion engine having a starter starter/alternator coupled to the crankshaft of the engine and a turbocharger having a rotor, said method comprising the steps of: 
       rotating the crankshaft of the engine with the starter/alternator; 
       rotating the rotor of the turbocharger to a predetermined speed; and  
       starting the engine when the turbocharger reaches the predetermined speed.  
     
     
       2. A method as recited in  claim 1  wherein the step of rotating the rotor shaft comprises the step of generating a mass airflow from the engine and coupling the mass airflow to said rotor shaft of the turbocharger. 
     
     
       3. A method as recited in  claim 2  wherein the step of rotating the rotor shaft comprises rotating the crankshaft of the vehicle with a starter starter/alternator and wherein the step of generating a mass airflow comprises the step of displacing air by moving pistons coupled to the crankshaft. 
     
     
       4. A method as recited in  claim 1  wherein the step of starting the engine comprises the step of operating the fuel pump; and providing fuel to cylinders of the engine. 
     
     
       5. A method as recited in  claim 1  further comprising the step of determining the approximate speed of the rotor shaft of the turbocharger from the length of time that the crankshaft has been rotated. 
     
     
       6. A method as recited in  claim 1  further comprising the step of generating power from the starter starter/alternator after the step of starting the engine. 
     
     
       7. A method of starting a vehicle with a starter, and a turbocharger and an internal combustion engine comprising the steps of: 
       rotating the crankshaft of the engine with the starter;  
       moving pistons in a respective cylinder;  
       displacing air into the exhaust system with the piston;  
       rotating a shaft of the turbocharger with the displaced air to a predetermined speed; and  
       starting the engine when the turbocharger reaches the predetermined speed.  
     
     
       8. A method as recited in  claim 7  wherein the step of rotating the rotor shaft comprises the step of generating a mass airflow from the engine and coupling the mass airflow to said rotor shaft of the turbocharger. 
     
     
       9. A method as recited in  claim 7  wherein the step of starting the engine comprises the step of operating the fuel pump; and providing fuel to cylinders of the engine. 
     
     
       10. A method as recited in  claim 7  further comprising the step of determining the approximate speed of the rotor shaft of the turbocharger from the length of time that the crankshaft has been rotated. 
     
     
       11. A method as recited in  claim 7  further comprising the step of generating power from the starter after the step of starting the engine. 
     
     
       12. A system for an automotive vehicle comprising: 
       an internal combustion engine having a crankshaft coupled to pistons;  
       a turbocharger having a rotor shaft;  
       a starter/alternator coupled to the crankshaft;  
       a controller coupled to the starter/alternator initiating the rotation of said crankshaft to displace air from the pistons and rotate the rotor shaft of said turbocharger, said controller starting said engine upon the rotor shaft reaching a predetermined speed.  
     
     
       13. A system as recited in  claim 12  further comprising a fuel pump. 
     
     
       14. A system as recited in  claim 13  wherein said controller operating said fuel pump during starting the engine. 
     
     
       15. A system as recited in  claim 12  wherein said starter is a starter/alternator. 
     
     
       16. A system as recited in  claim 12  further comprising a speed sensor coupled to the shaft of the turbocharger. 
     
     
       17. A system as recited in  claim 12  further comprising a power inverter coupled to said starter. 
     
     
       18. A system as recited in  claim 12  further comprising an energy storage device coupled to said power inverter.