Liquid fuel carburetion system

• US 4,329,964 A
• Filed: 11/25/1980
• Issued: 05/18/1982
• Est. Priority Date: 03/17/1978
• Status: Expired due to Term

• Current Assignee: George Q. Morris
• Original Assignee: George Q. Morris
• Inventors: Morris, George Q.
• Primary Examiner(s): Lazarus, Ronald H.
• Application Number:
  US06/210,187
• Time in Patent Office: 539 Days
• Field of Search: 123/545, 123/546, 123/557, 261/144, 261/145, 261/142, 261/DIG. 68, 261/41 D
• US Class Current: 123/557
• CPC Class Codes: F02M 3/12 Passageway systems
• CPC Class Codes: F02M 5/02 with provisions to meet variations in carburettor position, e.g. upside-down position in aircraft
• CPC Class Codes: F02M 7/10 Other installations, without moving parts, for influencing fuel/air ratio, e.g. electrical means fuel aerating devices for influencing fuel/air ratio F02M7/23

Abstract

A carburetion system for metering liquid fuel for supply to an internal combustion engine. Liquid fuel is metered in a single bifurcated metering system by being flowed through a calibrated orifice in response to a proportional pressure reduction which is generated as the result of the summing of a venturi pressure reduction and an auxiliary pressure reduction. Metered liquid fuel is delivered through one branch of the metering system to the engine intake air downstream of the throttle at small and medium engine loads, and through the other branch to the engine intake air upstream of the throttle at large engine loads. Transitioning of fuel flow between the branches is automatic and occurs in response to pressure differences within the system. Fuel delivered to the engine intake air downstream of the throttle valve may be heated or otherwise treated to improve liquid fuel atomization or vaporization.

Claims

1. A carburetion system for an internal combustion engine comprising:

air inlet means of fixed configuration having upstream and downstream ends;

a fuel reservoir adapted to contain an essentially constant level of fuel therein;

first passageway means of predetermined fluid flowing capacity, for flowing air out of said air inlet means and fuel into said air inlet means, extending between said air inlet means proximate the upstream end thereof and said fuel reservoir below the level of fuel therein;

throttle valve means disposed in said air inlet means downstream from said first conduit means;

second passageway means of predetermined fluid flowing capacity for flowing air and fuel from said first passageway means to said air inlet means at a location downstream from said throttle valve means;

said second passageway means connected to said first passageway means at a location such that air flows from said air inlet means through said first passageway means into said second passageway means when the engine is at idle load conditions;

air flow from said first passageway means into said second passageway means causing a pressure reduction of predetermined magnitude in said first passageway means;

said predetermined fluid flowing capacity of said first passageway means being specifically proportioned to said predetermined fluid flowing capacity of said second passageway means so as to determine said magnitude of said pressure reduction; and

said magnitude being determined such that an essentially correct amount of fuel is metered to the engine for engine operation at all speeds and loads.

2. The carburetion system according to claim 1 including:

fuel vaporizing means for vaporizing liquid fuel flowing through said second passageway means.

3. A carburetion system according to claim 1 wherein said second passageway means is connected to said first passageway means at a location which is at a distance, spaced from the air inlet, equal to at least one-half the perimeter of said first passageway means at the connection to said second passageway means.

4. A carburetion system according to claim 1 wherein adjustable valve means is provided in said second passageway means for adjusting said predetermined fluid flowing capacity of said second passageway means.

5. A carburetion system according to claim 1 wherein the majority of said fuel delivered to said air inlet is delivered by said second passageway means at small engine loads and by said first passageway means at large engine loads.

6. A carburetion system according to claim 1 wherein said first and second passageway means constitute the only passageway means for flow of fuel from said reservoir to said air inlet means.

7. A carburetion system according to claim 1 wherein only air is flowed through said second passageway means at engine idle load conditions.

8. A carburetion system according to claim 1 wherein the fuel is flowed through said second passageway means at engine idle load conditions.

9. A carburetion system according to claim 1 wherein the majority of engine idle load fuel is delivered to said air inlet means by said second passageway means.

10. A carburetion system according to claim 1 wherein all engine idle load fuel is delivered to said air inlet means by said second passageway means.

11. A carburetion system according to claim 1 wherein said predetermined fluid flowing capacity of said first passageway means is at least sufficient to allow flow of essentially all fuel required for engine operation at maximum engine load conditions.

12. The carburetion system according to claim 1 wherein a venturi pressure reduction is generated in said air inlet and applied to said first passageway means.

13. A carburetion system according to claim 1 wherein said magnitude of said auxiliary pressure reduction is determined such that at engine idle load condition fuel rises in said first passageway means above the plane of the fuel level in the reservoir to essentially the location of the connection of said second passageway means to said first passageway means.

14. A carburetion system according to claim 1 wherein said magnitude of said auxiliary pressure reduction is determined such that the correct amount of fuel for engine idling flows from said reservoir into said first passageway means at idle load conditions.

15. A carburetion system according to claim 1 wherein said connection of said second passageway means to said first passageway means is at a location that is essentially centered above the fuel in the fuel reservoir.

16. A carburetion system for an internal combustion engine comprising:

an air inlet into the engine, said air inlet being of fixed configuration and having upstream and downstream ends;

a fuel reservoir adapted to contain a level of liquid fuel therein;

main conduit means of predetermined fluid flowing capacity;

said main conduit means intersecting said air inlet proximate said upstream end such that a pressure reduction proportional to the quantity of air flowing through said air inlet is applied to said main conduit means;

throttle valve means disposed in said air inlet downstream from said intersection;

fuel conduit means connecting said main conduit means to liquid fuel in said reservoir;

auxiliary conduit means of predetermined fluid flowing capacity connected to said main conduit means and connected to said air inlet downstream from said throttle valve means;

the connection of said auxiliary conduit means to said main conduit means located above the plane of the liquid fuel level in said reservoir when the engine is operating at idle load condition such that air from said air inlet is flowed through said main conduit means into said auxiliary conduit means to cause an auxiliary pressure reduction of predetermined magnitude to be generated in said main conduit means;

said predetermined fluid flowing capacity of said auxiliary conduit means specifically proportioned to said predetermined fluid flowing capacity of said main conduit means such that the quantity of air flowed into said auxiliary conduit means from said main conduit means determines said magnitude of said auxiliary pressure reduction;

said auxiliary pressure reduction being such that an essentially correct amount of fuel is metered to said engine at all speeds and loads;

said pressure reduction and auxiliary pressure reduction functioning cooperatively in acting on said fuel conduit means to cause fuel to flow from said fuel reservoir into said fuel conduit means;

whereby fuel is metered from said fuel conduit means into said main and auxiliary conduit means to be delivered to said air inlet.

20. A carburetion system according to claim 16 or 17 or 18 including fuel vaporizing means interposed in said auxiliary conduit means for vaporizing fuel flowing through said auxiliary conduit means.

21. A carburetion system according to claims 16 or 17 wherein said connection of said auxiliary conduit means to said main conduit means is located at least a minimum distance from said intersection of said main conduit means with said air inlet, said minimum distance being equal to the perimeter of said main conduit means at said intersection with said air inlet.

22. A carburetion system according to claims 16 or 17 or 18 wherein adjustable valve means is provided in said auxiliary conduit means for adjusting said predetermined fluid flowing capacity of said auxiliary conduit means.

23. A carburetion system according to claims 16 or 17 or 18 wherein fuel is flowed through said auxiliary conduit means at engine idle load conditions.

24. A carburetion system according to claims 16, 17, 18 or 19 wherein said fuel conduit means has a predetermined fluid flowing capacity such that the correct amount of fuel for engine operation at all speeds and loads flows through said fuel conduit means in response to said cooperative action of said pressure reduction and auxiliary pressure reductions.

25. A carburetion system according to claims 16 or 17 or 18 wherein said connection of said auxiliary conduit means to said main conduit means is at a location that is essentially centered above the fuel in the fuel reservoir.

26. A carburetion system according to claims 16 or 17 or 18 wherein the majority of said fuel delivered to said air inlet is delivered by said auxiliary conduit means at small engine loads and by said main conduit means at large engine loads.

27. A carburetion system according to claims 16 or 17 or 18 wherein said magnitude of said auxiliary pressure reduction is determined such that at engine idle load condition fuel rises in said fuel conduit means above the plane of the fuel level in the reservoir to essentially the location of the connection of said auxiliary conduit means to said main conduit means.

35. The carburetion system according to claim 20 wherein said vaporizing means is a heater adapted to provide heat sufficient for fuel vaporization.

17. A carburetion system for an internal combustion engine comprising:

an air inlet into the engine, said air inlet being of fixed configuration and having upstream and downstream ends;

a fuel reservoir adapted to contain a level of liquid fuel therein;

main conduit means of predetermined fluid flowing capacity;

said main conduit means intersecting said air inlet proximate said upstream end such that a pressure reduction proportional to the quantity of air flowing through said air inlet is applied to said main conduit means;

throttle valve means disposed in said air inlet downstream from said intersection;

fuel conduit means connecting said main conduit means to liquid fuel in said reservoir;

auxiliary conduit means of predetermined fluid flowing capacity connected to said main conduit means and connected to said air inlet downstream from said throttle valve means;

the connection of said auxiliary conduit means to said main conduit means located between said intersection and any operating level of essentially liquid fuel in said main and fuel conduit means when the engine is operating at idle load condition such that air from said air inlet is flowed through said main conduit means into said auxiliary conduit means to cause an auxiliary pressure reduction of predetermined magnitude to be generated in said main conduit means;

said predetermined fluid flowing capacity of said auxiliary conduit means specifically proportioned to said predetermined fluid flowing capacity of said main conduit means such that the quantity of air flowed into said auxiliary conduit means from said main conduit means determines said magnitude of said auxiliary pressure reduction;

said auxiliary pressure reduction being such that an essentially correct amount of fuel is metered to said engine at all speeds and loads;

said pressure reduction and auxiliary pressure reduction functioning cooperatively in acting on said fuel conduit means to cause fuel to flow from said fuel reservoir into said fuel conduit means;

whereby fuel is metered from said fuel conduit means into said main and auxiliary conduit means to be delivered to said air inlet.

18. A carburetion system for an internal combustion engine comprising:

air inlet conduit means of fixed configuration supplying air to said engine;

venturi means disposed in said air inlet conduit means for generating a pressure reduction proportional to the amount of air flowing therethrough;

throttle valve means disposed in said air inlet conduit means downstream from said venturi means;

liquid fuel reservoir means;

main conduit means of predetermined fluid flowing capacity in communicative connection with said air inlet conduit means proximate said venturi means such that said pressure reduction is applied to said main conduit means;

fuel conduit means connecting said main conduit means to said liquid fuel reservoir means for transporting liquid fuel from said reservoir to said main conduit means;

auxiliary conduit means of predetermined fluid flowing capacity connecting said main conduit means to said air inlet conduit means at a location downstream of said throttle valve means;

said connection of said auxiliary conduit means to said main conduit means located between said connection of said main conduit means with said air inlet conduit means and any operating level of essentially entirely liquid fuel in said fuel conduit and main conduit means when said engine is operating at idle load condition such that air from said air inlet conduit means is flowed through said main conduit means into said auxiliary conduit means to cause an auxiliary pressure reduction of predetermined magnitude to be generated in said main conduit means;

said predetermined fluid flowing capacity of said auxiliary conduit means being specifically proportioned to said predetermined fluid flowing capacity of said main conduit means such that the quantity of air flowed into said auxiliary conduit means from said main conduit means determines said magnitude of said auxiliary pressure reduction;

said auxiliary pressure reduction being such that an essentially correct amount of fuel is metered to said engine at all speeds and loads;

said pressure reduction and auxiliary pressure reduction functioning cooperatively in acting on said fuel

conduit means to cause fuel to flow from said reservoir into said fuel conduit means;

whereby fuel is delivered from said fuel reservoir to said air inlet conduit means.

19. A carburetion system for an internal combustion engine comprising:

air inlet conduit means of fixed configuration supplying air to said engine;

venturi means disposed in said air inlet conduit means for generating a pressure reduction proportional to the amount of air flowing therethrough;

throttle valve means disposed in said air inlet conduit means downstream from said venturi means;

liquid fuel reservoir means;

main conduit means of predetermined fluid flowing capacity in communicative connection with said air inlet conduit means proximate said venturi means such that said pressure reduction is applied to said main conduit means;

fuel conduit means connecting said main conduit means to said liquid fuel reservoir means for transporting liquid fuel from said reservoir to said main conduit means;

fuel vaporizing means for vaporizing liquid fuel;

fuel vaporizing inlet conduit means of predetermined fluid flowing capacity connecting said main conduit means to said vaporizing means;

said connection of said fuel vaporizing inlet conduit means to said main conduit means located between said connection of said main conduit means with said air inlet conduit means and any operating level of essentially entirely liquid fuel in said fuel conduit and main conduit means when said engine is operating at idle load condition such that air from said air inlet conduit means is flowed through said main conduit means into said fuel vaporizing inlet conduit means to cause an auxiliary pressure reduction of predetermined magnitude to be generated in said main conduit means;

said predetermined fluid flowing capacity of said fuel vaporizing inlet conduit means being specifically proportioned to said predetermined fluid flowing capacity of said main conduit means such that the quantity of air flowed into said fuel vaporizing inlet conduit means from said main conduit means determines said magnitude of said auxiliary pressure reduction;

said auxiliary pressure reduction being such that an essentially correct amount of fuel is metered to said engine at all speeds and loads;

said pressure reduction and auxiliary pressure reduction functioning cooperatively in acting on said fuel conduit means to cause fuel to flow from said reservoir into said fuel conduit means; and

fuel vaporizing outlet conduit means connecting said fuel vaporizing means to said air inlet conduit means at a location downstream of said throttle valve means;

whereby fuel is delivered from said fuel reservoir to said air inlet conduit means.

28. A method for metering fuel to an internal combustion engine in a fuel system having:

an air inlet of fixed configuration into the engine;

a fuel reservoir;

throttle valve means disposed in said air inlet; and

first passageway means of predetermined fluid flowing capacity connected to said air inlet upstream from said throttle valve means and connected to fuel in said fuel reservoir, said method comprising;

flowing air from said first conduit means to said air inlet downstream from said throttle valve means through second passageway means of predetermined fluid flowing capacity;

generating a pressure reduction of predetermined magnitude in said first passageway means, said pressure reduction resulting from the air flowing out of said first passageway means into said second passageway means;

flowing air from said air inlet into said first passageway means to replace air flowed out of said first passageway means into said second passageway means;

specifically proportioning said predetermined fluid flowing capacity of said second passageway means to said predetermined fluid flowing capacity of said first passageway means such that said magnitude of said pressure reduction is determined; and

determining said magnitude such that an essentially correct amount of fuel is delivered from said reservoir to said engine at all speed and load conditions.

29. A method according to claim 28 including the step of vaporizing liquid fuel flowing through said second passageway means by means of a vaporizer interposed in said second passageway means.

30. A method according to claim 28 wherein said predetermined fluid flowing capacity of said second passageway means is adjustable.

31. A method according to claim 28 wherein only air flows through said second passageway means at engine idle load conditions.

32. A method according to claim 28 wherein the majority of fuel delivered to said air inlet is delivered by said second passageway means at small engine loads and by said first passageway means at large engine loads.

33. A method according to claim 28 where essentially all engine idle load fuel flows through said second passageway means.

34. A method according to claim 28 including the step of generating a venturi pressure reduction in said air inlet proportional to the amount of air flowing therethrough, and applying said venturi pressure reduction to said first passageway means.