Modular fuel control apparatus

• US 20030234002A1
• Filed: 01/31/2003
• Published: 12/25/2003
• Est. Priority Date: 07/10/2000
• Status: Abandoned Application

• Current Assignee: Lycoming Engines
• Original Assignee: Lycoming Engines
• Inventors: Rivera, Donald J.
• Application Number:
  US10/355,273
• Publication Number:
  US 20030234002A1
• Time in Patent Office: Days
• US Class Current: 123/454
• CPC Class Codes: F02M 17/04 having fuel inlet valve controlled by diaphragm
• CPC Class Codes: F02M 19/035 Mushroom-shaped atomising nozzles
• CPC Class Codes: F02M 19/12 External control gear, e.g. having dash-pots dampening means in later stages of multi-stage carburettors F02M11/04

Abstract

The present invention provides a fuel control apparatus with a modular fuel pressure modifying mechanism (i.e., a fuel metering section) and modular fuel regulator mechanism (i.e.. r fuel regulator section) that can each be calibrated independently of each other, and independent from the modular air passage mechanism (i.e., an airflow section). The air passage mechanism has an air intake end and an air outlet end and is constructed and arranged to accommodate airflow therethrough. the air passage mechanism having a first surface portion formed on an outer surface thereon. The modular fuel pressure modifying mechanism is constructed and arranged to receive fuel from a supply and deliver a portion of the hid at a pressure that is different from the pressure of the fuel supply, the modular fuel pressure modifying mechanism being removably mountable to the first surface portion of the air passage mechanism. The modular fuel pressure modifying mechanism is constructed and arranged to he calibrated prior to being mounted to the air passage mechanism. The fuel regulator mechanism is constructed and arranged to communicate with the airflow in the air passage mechanism and the modular fuel pressure modifying mechanism to regulate an amount of fuel delivered to the engine. The modular fuel pressure modifying mechanism and the modular fuel regulator mechanism are removably mountable to the modular air passage mechanism independently from each other.

Claims

1. A fuel control apparatus for an internal combustion engine, said fuel control apparatus comprising:

a modular air passage mechanism having an air intake end and an air outlet end, said modular air passage mechanism being constructed and arranged to accommodate airflow therethrough, the modular air passage mechanism having a first surface portion formed un an outer surface thereon;

a modular fuel pressure modifying mechanism constructed and arranged to receive fuel from a supply and deliver a portion of the fuel at a pressure that is different from the pressure of the fuel supply, the modular fuel pressure modifying mechanism being removably mountable to the first surface portion of the air passage mechanism;

the modular fuel pressure modifying mechanism constructed and arranged to be calibrated prior to being mounted to the air passage mechanism.

2. The fuel control apparatus of claim 1, wherein the modular fuel pressure modifying mechanism comprises a second surface portion formed thereon, the second surface portion corresponding to the first surface portion of the air passage mechanism when the modular fuel pressure modifying mechanism is removably mounted thereto.

3. The fuel control apparatus of claim 1, further comprising:

a modular fuel regulator mechanism constructed and arranged to communicate with the airflow in the air passage mechanism and the modular fuel pressure modifying mechanism to regulate an amount of fuel delivered to the engine.

4. The fuel control apparatus of claim 3, wherein the fuel regulator mechanism is a modular fuel regulator mechanism, and is constructed and arranged to be calibrated prior to being mounted to the modular air passage mechanism.

5. The fuel control apparatus of claim 1, wherein the first and second surface portions are mating planar surfaces.

6. The fuel control apparatus of claim 3, wherein the modular air passage mechanism further comprises:

an airflow inhibiting device pivotally mounted within the airflow channel, said airflow inhibiting mechanism constructed and arranged to be actuated by a user, wherein actuation of the airflow inhibiting device varies its orientation within the channel to regulate the amount of air that flows therethrough to the engine.

7. The fuel control apparatus of claim 3, wherein the air passage mechanism further comprises:

a venturi being mounted within the airflow channel of the main body, the venturi constructed and arranged to cause a pressure differential in the air flowing through the air passage mechanism, the pressure differential being the difference between air pressure generated by the venturi and air pressure generated by the impact of ambient air onto the modular air passage mechanism, said ambient air being substantially unaffected by the venturi, the pressure differential to be communicated to the fuel regulator mechanism.

8. The fuel control apparatus of claim 7, wherein the venturi is formed in the shape of a bullet, the venturi being constructed and arranged to cause a drop in the air pressure as the air flows over the venturi.

9. The fuel control apparatus of claim 6, wherein said modular fuel regulator mechanism further comprises:

an air diaphragm separating a first air diaphragm chamber and a second air diaphragm chamber, the air pressure generated by the venturi to communicate with the first air diaphragm chamber and the impact air pressure to communicate with the second air diaphragm chamber.

10. The fuel control apparatus of claim 9, wherein said modular fuel regulator mechanism further comprises:

a fuel diaphragm separating a metered fuel diaphragm chamber and an unmetered fuel diaphragm chamber.

11. The fuel control apparatus of claim 10, wherein said modular fuel regulator mechanism further comprises:

a regulator stem having a first end and a second end, said first end being connected to the air diaphragm, the second end constructed and arranged to operate as a portion of a fuel valve, the regulator stem being connected at an intermediate portion thereof to the fuel diaphragm.

12. The fuel control apparatus of claim 11, wherein said modular fuel regulator mechanism further comprises a center body separating the air chambers from the fuel chambers.

13. The fuel control apparatus of claim 12, wherein said modular fuel regulator mechanism further comprises:

a bellows cage mounted centrally of the center body, the bellows cage housing a bellows.

14. The fuel control apparatus of claim 13, wherein said modular fuel regulator mechanism further comprises:

a fuel valve seat constructed and arranged to be engaged by the second end of the regulator stem, the fuel valve seat and said second end comprising the fuel valve.

15. The fuel control apparatus of claim 14, wherein said modular fuel regulator further comprises:

a fuel valve seat fitting to house the fuel valve, the fitting being constructed and arranged to enable proper positioning of the fuel valve seat with respect to the air diaphragm, fuel diaphragm, and regulator stem.

16. The fuel control apparatus of claim 9, wherein the modular pressure modifying mechanism further comprises:

a fuel inlet port for receiving fuel from the fuel supply.

17. The fuel control apparatus of claim 16, wherein the modular pressure modifying mechanism further comprises:

a control valve that is constructed and arranged to split the flow of fuel into a first path and a second path, said first path being a path from unmetered fuel in direct communication with the modular fuel regulator mechanism.

18. The fuel control apparatus of claim 17, wherein the control valve is constructed and arranged to be actuated by the user.

19. The fuel control apparatus of claim 18, wherein the second path is constructed and arranged to direct fuel to at least one metering jet, the at least one metering jet having an orifice therethrough to reduce fuel pressure in the second path as fuel flows through the orifice

20. The fuel control apparatus of claim 18, wherein the second path is a path for metered fuel and is to be communicated with the fuel regulator mechanism.

21. The fuel control apparatus of claim 20, the modular pressure modifying mechanism further comprises:

a metered fuel valve actuated by the user, the metered fuel valve being constructed and arranged such that actuation thereof regulates the amount of fuel that flows from the second path to the engine, the metered fuel valve also being constructed and arranged to vary the engine speed from an idle power to a full power, the metered fuel valve at idle power being iii an idle speed position and at full power being in a full power position.

22. The fuel control apparatus of claim 21, wherein the modular pressure modifying mechanism further comprises an enrichment circuit assembly, the enrichment circuit assembly comprising:

a diaphragm separating a metered enrichment chamber and an unmetered enrichment chamber, the metered enrichment chamber being in communication with the second path and the unmetered enrichment chamber being in communication with the first path.

23. The fuel control apparatus of claim 22, wherein the enrichment circuit assembly further comprises:

an enrichment valve resiliently biased by a spring interconnected to the diaphragm, the enrichment valve being constructed and arranged to allow fuel in the unmetered enrichment chamber to pass into the metered enrichment chamber when the enrichment valve is open, the valve being caused to be open when a pressure differential across the diaphragm creates a force greater than that required to compress the spring.

24. The fuel control apparatus of claim 23, wherein the enrichment circuit assembly further comprises an enrichment valve jet mounted within the enrichment valve to control the amount of fuel that passes through the enrichment valve when the valve is open.

25. The fuel control apparatus of claim 24, wherein fuel in the metered enrichment chamber is communicated to the modular fuel regulator mechanism and the fuel in the unmetered enrichment chamber also is communicated to the modular fuel regulator mechanism. the enrichment circuit assembly increasing the fuel/air mixture ratio to provide cooling of the engine.

26. The fuel control apparatus of claim 1, wherein said engine is used to power an aircraft.

27. The fuel control apparatus of claim 1, wherein said engine comprises at least one combustion cylinder.