Air-assisted fuel evacuation system
View Patent ↗A system and method are provided for evacuating fuel from a closed-loop fuel rail after engine testing. The method includes coupling a coaxial hose to a closed-loop fuel rail of an engine. The coaxial hose defines an outer tube section defining an outer passage and surrounding an inner tube section defining an inner passage, and a portion of the inner tube section is inserted a predetermined distance into the fuel rail. The method includes transferring fuel from a fuel supply through the outer passage of the coaxial hose and into the fuel rail for use during an engine testing procedure. After the engine testing procedure is complete, the method includes injecting compressed gas through the inner passage and into the fuel rail, creating a positive pressure. Residual fuel is evacuated from the fuel rail out through the outer passage of the coaxial hose.
1. A system for evacuating residual fuel from a fuel rail of an engine, the system comprising:
a source of compressed gas;
a coaxial hose including an outer tube section defining an outer passage in fluid communication with a fuel supply and an inner tube section defining an inner passage in fluid communication with the source of compressed gas;
a coupling member disposed at a first end of the coaxial hose for removably coupling the coaxial hose to the fuel rail; and
a valve assembly disposed at a second end of the coaxial hose and configured to provide:
selective fluid communication between the outer passage and a fuel supply to transfer fuel to the fuel rail for engine testing; and
selective fluid communication between the inner passage and the source of compressed gas for pressurizing the fuel rail and evacuating residual fuel back through the outer passage upon completion of the engine testing.
2. The system according to claim 1 , wherein the valve assembly comprises a valve fitting defining a first port providing fluid communication with the outer passage, and a second port providing fluid communication with the inner passage.
3. The system according to claim 2 , wherein the valve fitting comprises a brass tee fitting.
4. The system according to claim 1 , further comprising an extension member fixed to the coupling member and in fluid communication with the inner passage, the extension member extending a predetermined linear distance into the fuel rail when the coaxial hose is coupled to the fuel rail.
5. The system according to claim 4 , wherein the predetermined linear distance is greater than about 80% of a length dimension of the fuel rail.
6. The system according to claim 4 , wherein the inner tube section comprises a polyurethane tube, the outer section comprises a rubber hose, and the extension member comprises a nylon tube.
7. The system according to claim 1 , wherein the fuel rail is part of a closed-loop structure.
8. A tube fitting assembly for evacuating fuel from a closed-loop fuel rail of an engine, the assembly comprising:
an outer hose in fluid communication with a fuel supply;
an inner tube disposed within the outer hose and in fluid communication with a source of compressed gas;
a coupling member for removably coupling the outer hose and the inner tube to the fuel rail;
an extension member fixed to the coupling member and in fluid communication with the inner tube, the extension member configured to extend a predetermined distance into the fuel rail when the coupling member is coupled to the fuel rail; and
a valve assembly coupled to the outer hose and inner tube, the valve assembly providing selective fluid communication between the outer hose and a fuel supply to transfer fuel to the fuel rail for engine testing, and the valve assembly further providing selective fluid communication between the inner tube and a source of compressed gas for evacuating residual fuel remaining in the fuel rail out through the outer hose upon completion of the engine testing.
9. The fitting assembly according to claim 8 , extension member comprises a length greater than about 80% of a length dimension of the fuel rail.
10. The fitting assembly according to claim 8 ; wherein the inner tube comprises a polyurethane tube, the outer hose comprises a rubber hose, and the extension member comprises a nylon tube.
11. A method for evacuating fuel from a closed-loop fuel rail after engine testing, the method comprising:
coupling a coaxial hose to a closed-loop fuel rail of an engine, the coaxial hose including an outer tube section defining an outer passage and surrounding an inner tube section defining an inner passage, a portion of the inner tube section being inserted a predetermined distance into the fuel rail;
transferring fuel from a fuel supply through the outer passage of the coaxial hose and into the fuel rail for use during an engine testing procedure;
after the engine testing procedure is complete, injecting compressed gas through the inner passage and into the fuel rail, creating a positive pressure; and
evacuating residual fuel from the fuel rail out through the outer passage of the coaxial hose.
12. The method according to claim 11 , further comprising removing at least a portion of the residual fuel prior to injecting compressed gas through the inner passage.
13. The method according to claim 12 , wherein the removing at least a portion of the residual fuel comprises engaging a vacuum source in fluid communication with the outer passage of the coaxial hose and drawing out residual fuel.
14. The method according to claim 13 , further comprising repeated alternating steps of drawing out residual fuel using the vacuum source and injecting compressed gas into the fuel rail.
15. The method according to claim 11 , wherein the coaxial hose comprises a coupling member disposed at a first end for removably coupling the coaxial hose to the fuel rail, and a valve assembly disposed at a second end for selectively directing fuel and compressed gas through respective passages of the coaxial hose.
16. The method according to claim 15 , wherein the valve assembly comprises a first port providing selective fluid communication between the outer passage and the fuel supply, and a second port providing selective fluid communication between the inner passage and a source of compressed gas.
17. The method according to claim 15 , wherein the fuel rail comprises a plurality of spaced-apart fuel injectors including a proximal position fuel injector and a distal position fuel injector, and the portion of the inner tube section comprises an extension member fixed to the coupling member and inserted a distance into the fuel rail beyond the distal position fuel injector.
18. The method according to claim 11 , wherein the predetermined distance is greater than about 80% of a length dimension of the fuel rail.
19. The method according to claim 11 , comprising injecting compressed gas into the fuel rail for a predetermined period of time prior to decoupling the coaxial hose from the closed-loop fuel rail.
20. The method according to claim 11 , wherein the steps of injecting the compressed gas through the inner tube section and into the fuel rail, and evacuating residual fuel from the fuel rail out through the outer tube section are performed concurrently.