Fuel Injection System

Abstract

A fuel injection system for injecting fuel into either a two or four cycle internal combustion engine including a housing having a drive shaft with fuel pumping means for pumping fuel through a distributing section into fuel injectors associated with the combustion chambers of the engine. At the fuel injectors, the fuel is atomized, mixed with air and ignited before being passed into the combustion chambers.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to internal combustion engines, and more particularly, to a system for injecting fuel into such engines.

2. Description of the Prior Act

Fuel injection systems for two and four cycle internal combustion engines are well known in the automotive art. Generally, such fuel injection systems are used in conjunction with an electrical ignition system comprising a distributor, ignition coil, points, condenser-rotor, distributor cap-spark plugs and spark plug wire for each cylinder. These systems inject fuel into the intake ports of the cylinder heads. However, with such systems, smog is produced and efficiency is reduced since, in two and four cycle engines, there is an overlap of the intake and exhaust cycles that allows a certain amount of the fresh fuel-air mixture to be drawn out through the exhaust port or valve. This scavengering of exhaust pulls an amount of fuel-air through the chambers in an unburnt state.

Further, such prior art fuel injection systems require spark plugs which sometimes require high grade fuels, such as leaded fuels, so that no slow down in combustion results. Also, since in such systems the fuel is injected into the intake manifold or cylinder head port, the fuel enters the combustion chamber in a liquid form instead of a fog thus causing incomplete combustion. Finally, such systems may have a common fuel line which connects all injectors. On these systems, the suction of the intake cycle sucks the fuel through an orifice in the injector into the intake port of the cylinder head and into the combustion chamber. Thus, droplets of fuel are injected into the combustion chamber resulting in incomplete combustion and lower fuel mileage and more smog.

With the emphasis today on improving the quality of air in our environment, a need exists for a fuel injection system for an internal combustion engine which can be made with improved smog-free characteristics over present systems, is adaptable to most pre-existing internal combustion engines and can operate with low-grade fuels.

SUMMARY OF THE INVENTION

It is an object of my invention to provide an improved fuel injection system for internal combustion engines which injects fuel directly into the combustion chamber of such engines.

It is a further object of my invention to provide such a fuel injection system which injects fuel at a pre-determined time directly into the combustion chamber of the internal combustion engine to thereby produce less smog.

It is a still further object of my invention to provide such a system which uses a glow plug having a longer spark life (or ionize period) thus permitting the use of lead-free low-grade fuels.

It is an even further object of this invention to provide a fuel injection system which can be adapted to most internal combustion engines now in use.

These and other objects as will be discussed further hereinbelow are preferably accomplished by providing a housing having a drive shaft with fuel pumping means for pumping fuel through a distributing section into fuel injectors associated with the combustion chambers of the engine. At the fuel injectors, the fuel is atomized, mixed with air and ignited before being passed into the combustion chambers.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a vertical sectional view of an fuel injection system in accordance with my invention; and

FIG. 2 is a side view of a throttle valve and air cleaner for use with the system of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing, a fuel injection system 10 is shown comprising a generally cylindrical housing 11 having a cap 12 sealing the top thereof and a drive shaft 13 extending therethrough for driving the internal parts of housing 11 as will be described hereinbelow. A plurality of fuel outlets 14 are provided about the upper portion of housing 11 communicating with the interior thereof for taking fuel under pressure from housing 11, through tubing 15 and into the fuel injector 16. These outlets 14 are preferably equally spaced around the sides of housing 11, such spacing being determined by the number of cylinders of the internal combustion engine with which the system 10 is to be used. Thus, one injector 16, one tubing 15 and one outlet 14 is associated with each cylinder.

A fuel inlet 17 communicates with the pump section 18 of housing 11 below outlets 14. Such inlet 17 is adapted to be connected to a fuel line (not shown) leading from a fuel supply (also not shown) and may be provided with a check ball valve 19, if desired, for keeping the pump section 18 from losing its prime and damaging internal parts thereof. The line connected to inlet 17 may be fed by a conventional fuel pump (not shown) or the like, if desired.

Preferably, the lower portion 20 of housing 11 necks down to a reduced neck portion 21 so that the entire housing 11 may be placed on an internal combustion engine in the position previously occupied by either the distributor or magneto of such engine.

A gear pump 22 is disposed on shaft 13. This pump 22 includes a pair of mating gears 22a and 22b, one of the gears 22aa fixed to shaft 13 and the other gear 22b being rotatably mounted on a shaft 22C fixedly mounted in pump section 18. Fluid communication (not shown) is provided between gears 22a and 22b for passing fluid from one side of gear pump 22 to the other as is well known in the art. Contacting portions of pump section 18 and gear pump 22 may be made of Teflon or the like so as to improve circulation and boost fuel pressure. Fuel from pump section 18 is channeled as indicated by the arrows, to a conventional pressure regulator 23 for regulating the volume and pressure of fuel and also permitting a small amount of fuel to bypass for lubrication.

From regulator 23, the fuel enters a fuel cavity 24 in communication with both an override pressure regulator 25 and a throttling valve 26. The regulator 25 is designed to limit the maximum fuel pressure and also permit a small amount of fuel to leak by and keep components of the pump section 18 from scuffing against one another and also for lubrication of these components. The excess fuel, after being bypassed by regulator 25, is then channeled back to the suction side, i.e., the right hand side of FIG. 1, of pump section 18 along with the leak-off fuel.

Throttling valve 26 is actuated by suitable control means (not shown) and regulates the amount of fuel under pressure that enters the rotor cavity formed in the upper portion 27 of housing 11. This fuel entering the rotor cavity then enters through an aperture 28 formed in a distributor rotor 29. Rotor 29 is also disposed on shaft 13. As shaft 13 is rotated, the rotor aperture 28 indexes with like apertures 30 formed in a distributor housing 31 fixedly mounted in housing 11. These apertures 30 also communicate with fuel outlets 14 as shown.

Distributor housing 31 includes an aperture for each individual cylinder (not shown) that is connected to the fuel outlets 14. Thus, only two such apertures 30 are shown in FIG. 1. When rotor aperture 28 indexes with one of the distributor apertures 30, fuel under pressure is forced through the aperture 30 to fuel outlet 14 and thus into injector 16. Mating surfaces of rotor 29 and housing 31 may also be made of Teflon or similar material so as to prevent scuffing or wear.

A centrifugal advance mechanism 32 is also disposed on shaft 13 above distributor housing 31. This mechanism 32 advances the fuel injection timing to the injector or injectors 16 and the combustion chambers of the internal combustion engine (not shown). Advance of rotor 29 is accomplished by means of a sleeve 33 coupling rotor 29 to mechanism 32. All of the housings 31, 34 (housing 34 housing the throttling valve 26 and regulator 25) and 35 (housing 35 housing gear pump 8 and the various elements of pump section 18) are preferably sealed within housing 11 by O-rings 36 or the like.

An aperture 37 is formed in lower housing portion 20 that may be either capped or used as a return to the fuel supply tank (not shown) to take up excess fuel that seeps past gear pump 22. A like aperture 38 may be formed in reduced neck portion 21 to serve as an emergency drain that may be piped to a sight glass (not shown) so that the housing 11 may be serviced if fuel is visible.

A shaft bearing 39 surrounds shaft 13 between the inner wall 40 and shaft 13 so that the shaft rotates therein. A similar bearing 39a is disposed between sleeve 33 and housing 31. A gear 41 may be mounted on the bottom of shaft 13 for driving the shaft 13 (instead of driving shaft 13 through means of a distributor or magneto or the like). Fuel leakage past shaft 13 and bearing 39 is prevented by means of one or more seals 42. A spring 43 surrounds shaft 13 between rotor 29 and housing 34 to maintain pressure on rotor 29 and prevent fuel from entering the distributor aperture 30 which is not aligned with rotor aperture 28 during operation thereof.

The fuel under pressure is piped out outlet or outlets 14 through tubing 15 to injector 16 (only one injector being shown for convenience of illustration--obviously, a like injector would be associated with each of the remaining outlets 14, the total of which being of course determined by the total number of cylinders in the vehicle). Tubing 15 is secured to fuel injector 16 by means of a fitting 44 mounted on a fitting housing 45. A spring-operated check ball valve 46 is disposed on housing 45 in communication with fuel entering therein. Valve 46 permits the flow of fuel to be cut off when the pressure drops below a certain value and prevents combustion gases from entering tubing 15.

From housing 45, the fuel enters fuel cavity 46a, cavity 46a being in communication with a plurality of apertures 47 extending through injector body 48 at an angle adapted to atomize the fuel when it leaves cavity 46a through apertures 47 under pressure. The diameter and angle of these apertures 47 depends upon the type of engine with which my system is to be used. This atomized fuel is then mixed with air (as will be discussed shortly) and ignited by the electrode 49 of a glow plug 50. Glow plug 50 is insulated as at insulation 51 from the upper body portion 52 of injector 16. The combustion chamber of the internal combustion engine is represented by chamber 53 and injector 16 is sealed thereto by means of a seal 54, which may be a copper gasket or the like.

FIG. 2 shows air intake means 55 that may take the place of a conventional carburetor when adapting a conventional internal combustion engine to the fuel injection system of my invention. Thus, air intake means 55 includes conventional air cleaner 56 mounted on an air throttle housing 57 containing a throttle butterfly plate 58 therein. The throttle butterfly plate 58 is controlled by a linkage 59 for controlling the passage of air to an air intake manifold 60. Linkage 59 is of course connected to the accelerator pedal of the vehicle. Thus, when valve 58 is closed, the opening is restricted, and when open, sufficient air can be admitted thus regulating, through linkage 59, the amount of air entering the combustion chamber of the vehicle. Such means 55 creates a vacuum that the piston of the engine (not shown) pulls against when valve 58 is closed thus helping slow down the vehicle on down hill grades and under deceleration. The air cleaner 56 may take any desired configuration and cleans the air prior to it entering the cylinder of the vehicle.

In operation, fuel is admitted to the interior of housing 11 through inlet 17. Shaft 13 is rotated thus pumping the admitted fuel, the pressure being regulated by regulator 23, into cavity 24 as discussed hereinabove and indicated by the arrows. Valve 26 regulates the amount of fuel to be distributed to rotor 29 in accordance with the position of throttling valve 26 as well known in the automotive art. The fuel enters aperture 28 in rotor 29 and from there the fuel is distributed to the individual cylinders of the vehicle through apertures 30 and into tubings 15.

The advance mechanism 32, rotated by shaft 13, advances the delivery of fuel by indexing rotor aperture 28 with the apertures 30 in housing 31 as is well known in the automotive art.

The fuel enters each injector 16 under pressure and through the interior 53a, via passageways 47, of combustion chamber 53. There the fuel is atomized as it comes from housing 11 via tubing 15 and apertures 47 and is injected into chamber 53 on the power cycle of that respective cylinder so as to convert liquid energy into mechanical energy. The check ball valve 46 in housing 45 prevents any fuel from dripping into the interior 53a of chamber 53 and keeps combustion gases out of tubing 15.

As discussed hereinabove with respect to FIG. 2, the desired amount of air is then mixed with the atomized fuel in the interior 53a of chamber 53 and the mixture is ignited by means of the electrode 49 of glow plug 50.

Unless otherwise indicated hereinabove, conventionally known parts may be used and assembled in the manner indicated. Also, all valves and/or other regulators and controls may be controlled from the dashboard and floor of the vehicle through suitable pedals, linkages, knobs, etc., all as is well known in the automotive art.

In summary, it can be thus seen that I have described a true fuel injection system because my system injects fuel directly into the combustion chamber rather than into the intake ports of the cylinder heads as in other prior art systems. Because my fuel injection system injects fuel directly into the combustion chamber instead of the intake port of the cylinders at a pre-determined time, it produces less smog and is more efficient since, on two and four cycle engines, there is an overlap of the intake and exhaust cycles that allows a certain amount of the fresh fuel air mixture to be drawn out through the exhaust port or valve. As discussed previously, this scavengering of exhaust pulls a certain amount of unburnt fuel-air through the chambers which cannot take place in may system since the fuel is injected on the power stroke and will have completed its combustion before the exhaust port or valve opens. When the exhaust valve or port opens, the fresh air being drawn through the chamber when the intake port or valve opens on the overlap cycle is fresh air with no fuel mixture in it.

Better gas mileage may be obtained with my system over other prior art systems because the atomization of fuel takes place in the combustion chamber where it is immediately burned as opposed to being injected into the intake manifold or cylinder head port which will let the fuel enter the combustion chamber in a liquid form instead of a fog, thus causing incomplete combustion.

The fuel injectors of my system are very efficient because they are calibrated and have check ball valves therein so the fuel injection cannot drop droplets of fuel into the combustion chamber until the fuel pump delivers fuel under pressure from the fuel pump to the injector through a line to that individual injector.

Since my system atomizes or breaks up the fuel into fine particles, there is better and more complete combustion which gives better fuel mileage and less smog.

Claims

I claim as my invention:

1. In a system for injecting fuel into an internal combustion engine having a plurality of cylinders therein, said system comprising:

a substantially enclosed housing having a chamber therein;

a drive shaft extending longitudinally of said housing and out one end thereof;

a plurality of fuel outlets communicating at one end with the interior of said housing and at the other end with a respective fuel injector;

fuel pumping means disposed in said housing and in driving engagement with said drive shaft for pumping fuel to each of said fuel injectors;

a fuel inlet communicating with said fuel pumping means for introducing fuel thereto;

a generally substantially flat plate-like distributor rotor having an aperture extending therethrough surrounding said shaft and in fluid communication with fuel being pumped from said fuel pumping means;

a distributor housing having a plurality of apertures therethrough fixedly mounted within said housing, said distributor housing apertures being in selective fluid communication with one of said fuel outlets and said distributor rotor aperture;

centrifugal fuel advance means fixedly mounted to shaft for rotating said rotor about its axis and thus advance said rotor to thereby selectively align said distributor rotor aperture with one of said distributor housing apertures for pumping fuel from said fuel pumping means, out said fuel outlet and to only one of said injectors at a time; and

drive shaft rotating means for rotating said drive shaft.

2. The system of claim 1 wherein said fuel outlets are substantially equally spaced about the upper portion of said housing.

3. The system of claim 1 wherein said fuel pumping means includes fuel regulating means therein for regulating the volume and pressure of fuel being pumped therethrough.

4. The system of claim 1 including tubing connected to each of said fuel outlets and said fuel injectors for providing fluid communication therebetween.

5. The system of claim 4 wherein said fuel injector comprises:

an injector body;

a housing mounted on said body having a chamber therein in fluid communication with said tubing;

a fluid cavity disposed in said body in fluid communication with said last-mentioned housing chamber; and

fuel atomizing means extending through said injector body communicating at one end with said fluid cavity and at the other end with a combustion chamber, said atomizing means being adapted to atomize the fuel being pumped from said cavity into said chamber under pressure.

6. The system of claim 5 wherein said fuel atomizing means includes a plurality of apertures of a restricted diameter extending at an angle from said cavity into said chamber.

7. The system of claim 6 including a glow plug disposed on said injector body, said glow plug being insulated therefrom and having an electrode extending into said combustion chamber.

8. The system of claim 5 including valve means disposed in said last-mentioned housing chamber for permitting the flow of fuel therethrough to be cut off when the fuel pressure drops below a predetermined value to thereby prevent combustion gases from entering said tubing.

9. The system of claim 5 including air intake means associated with said combustion chamber for supplying air thereto in an amount sufficient to support combustion within said chamber.

10. The system of claim 9 wherein said air intake means comprises:

an air cleaner;

an air chamber communicating with said air cleaner;

an air intake manifold communicating with said air chamber; and

air throttling means associated with said air chamber for receiving air from said air cleaner and passing a selected amount of said air through said air intake manifold into said combustion chamber.