US1679818A - Fuel injector for internal-combustion engines - Google Patents

Description

1,679,818 J. W. ENRIGHT FUEL INJECTOR FOR INTERNAL COMBUSTION ENGINES Filed Jan. 1925 2 $heets-$heet 1 @Hozucu Aug. 7, 1928. 1,679,818

J. W. ENRIGHT FUEL INJEQTOR FOR INTERNAL COMBUSTION ENGINES- Filed Jan. 1925 2 Sheets-Sheet 2 titl tilt

atented Aug. 7, 1928.

lTED STATES JOHN W. ENRIGHT, OF NEW ORLEANS, LOUISIANA.

FUEL INJECTOR FOB INTERNAL-COMBUSTION ENGINES.

Application filed January 5, 1925. Serial 110.628.

The present invention relates to improvements in internal combustion engines, and more particularly to those of the type adapted to operate on fuel oil or other relatively heavy or difiicultly volatile oil, and which employs an injectorfor vaporizing and in troducing the oil into a compressed charge of air contained in the engine cylinder to form therewith the explosive mixture.

The primaryobject of the invention is to provide a novel and improved fuel oil injector of this general class whereby greater economy and improved operating efiiciency are attained.

According to the present invention, the fuel oil is fed, in li uid form and in $110- cessive charges, to t e injector, and each charge of liquid fuel is subjected to the agitating action of air which is compressed by the compression of a charge of air in the engine cylinder, in consequence of which the liquid fuel charge is very finely atomizednnd introduced into a vapor reservoir in the injector. The charge of fuel in vapor form is then held in the vapor reservoir while it is being subjected to a higher pressure which is much greater than the pressure of the compressed charge of air contained in the engine cylinder, and when the charge offuel has been com ressed to a predetermined pressure and t us further vaporized into a substantially gaseous form, it is permitted to discharge from the vapor reservoir of the injector into the engine cylinder to mix therein with the body of compressed air to form the explosive charge.

To these and other ends, the invention consists in certain improvements and combinations and arrangements of parts, all as will be hereinafter more. fully described, the features of novelty being pointed out particularly in the claims at the end of the specification.

in the accompanying drawings Figure 1 represents an axial section taken through the head of the cylinder of an internal combustion engine, showing a fuel injector embodying the present invention applied thereto;

Figure Q represents, on an enlarged scale, a section taken axially through the fuel injector embodying the present invention;

Figure 3 represents a cross-section through the" inner end of the injector, the section being taken on the fine 3-3 of Figure 2 and looting in the dire ti n f the arrow Figure 4 is a view of the outer end of the ln ector;

Figure 5 is a detail view, on an enlarged scale and showing in axial section the constrpction of theinner end of the injector; an

Figure firepresents a cross-section on the line 6-6 of Figure 5.

Similar parts are designated by the same reference characters in the several figures.

The present invention is applicable generally to internal combustion engines of the kinds adapted to operate on liquid fuel, although it is particularly adapted for use on internal combustion engines of the kinds using fuel oil or other relatively heavy difficultly volatile oils, and wherein the liquid fuel is prepared for ignition and explosion in an in ector which operates to introduce or discharge the prepared fuel into a compressed charge of air contained in the engine cylinder, the prepared fuel so introduced mixing with the chargeof compressed air and forming therewith the explosive charge.

The preferred embodiment of the invention is represented in the accompanyingdrawings and is hereinafter described in detail, but it is tobe understood that the invention is not restricted to this particular embodiment, as equivalent constructions are contemplated and variations may be made in the mode of applying and working the invention, and these will be included within the scope of the claims.

In the present instance, 1 represents a portion of the cylinder of an internal combustion engine, 2 the cylinder head, 3 the piston which works in the cylinder and serves to compress charges of air in the combustion chamber 4 preparatory to the explosions which take place therein and to drive the usual crank shaft during its working strokes, and 5 designates the in-take and exhaust valves which may be operated or controlled in the usual or well-known way to admit air to the combustion chamber of the cylinder during the suction strokes of the piston and to exhaust the products of combustion from the combustion chamber upon completion of the working strokes of the piston.

The' fuel injector 6 embed ing the present invention is fitted into the cylinder or the cylinder head and is secured therein so that its inner end projects into or is in communication with the combustion Chums ber 4 of the cylinder. jector is fitted .into a pocket 7 which is formed in the cylinder head 2 and the injector is secured in place by flanges 8 on the injector body and which are bolted or otherwisesecured to the cylinder head.

he injector comprises a body 9 which is formed with a bore 10 into which is fitted a. piston or plunger 11, the piston or plunger having a substantially fluid-tight fit in the As shown, the inbore 10 and provided preferably with a grooving the outer stuffing box 12 which surrounds its outer end and prevents leakage of fuel from within the injector. The inner end of the bore 10 forms an air compressing chamber 13, the inner end of this chamber being preferably 'of substantially conical form, as indicated at 14, and the inner end of .the piston or plunger llhas a correspondingly shaped inner end 15. A passageway 16 is provided which communicates with the apex of'the conical end 14 of the 'bore 10, and this passageway communicates with a seat 17 with which a needle valve 18 cooperates. This needle valve serves to control or regulate the admission of liquid fuel from a liquid fuel supply'port 19 to the passageway 16. A spring 20 is provided which acts to normally hold the needle valve on its seat 17, although permitting the needle valve to be retracted and thereby disenaged from its seat 'to admit liquid fuel rom the supply port 19 to the passageway 16. e passageway 16 communicates at the inner side of the needle valve seat 17 with a port 21 which leads into the bore 10 of the injector, and the plunger 11 which operates in this-bore is grooved circumferentially or otherwise formed to produce a vapor reservoir 22w,ith which the port 21 communicates} Preferably, the inner end of the injector, which is reduced in diameter, isencased in a shell or casing 23 which fitsclosely upon thebody of the injector, and the passageway 16 may be formed by side of the injector body before the shell 23 is applied thereto. A suitable number of ports 24 lead from the bore 10 through the ,injector body'andthe shell 23 to the outerside these ports being located in the length of the bore 10 that they will be covered and thus closed by the inner end of the plunger 11, except when the plunger fully retracted, at which time these ports 24 will be uncovered and they will thereby establish communication between the combustion chamber 4 of the engine cylinder and the compressing chamber 13 within the injector. The ports 24 are also preferably distributed around the circumference of the inner end of the injector and extend radially of the compressing chamber at such a point 13. A spring 25 is preferably employed to retractthe plunger and to hold it in its of the injector,

retracted position, as is shown in Figure 2, this spring, in the present instance, bearing against an adjusting nut 26 which is threaded on the outer end of the plunger. A rocker 27 may be provided for retracting the needle valve 18 at appropriately timed intervals, and a rocker 28 may be provided for forcing the plunger 11 inwardly at appropriately timed intervals. These rockers may be operated in any suitable or well known way, as from a cam shaft connected to the crank shaft of the engine, and illustration of such operating means is, therefore, considered unnecessary. The operation of a fuel injector constructed in accordance with the present embodiment of the invention is as follows:

Normally the plunger 11 will occupy its retracted position, as is shown in Figure 2, and by the dotted lines in Figure 5, it being held in such position by its spring 25, and the needle valve 18 will normally be held in engagement with its seat 17 by the spring 20. At an appropriate time during the operation of the engine, as during the suction stroke .of the working piston 3, the rocker 27 is actuated to lift the needle valve 18 from its seat 17 and thus admit a supply of liquid fuel to the passageway 16, following which the needle valve returns to its seat. During the suction stroke of the piston 3, a charge of air is drawn into the cylinder, and during the following compression stroke of this piston, such air is compressed in the combustion chamber 4 of the cylinder. Part of the air thus compressed in the cylinder is forced into and through the ports 24 in the ejector, and this air enters the compressing chamber 13 under pressure and then flows out of this chamber through the passageway 16 and enters the vapor reservoir or chamber 22, and in so doing, such air passes through and carries with it the liquid fuel which was previously admitted to the passageway 16. The result is that the liquid fuel is atomized to a-substantial degree and it is transferred from the passageway 16 through the port 21 into the vapor reservoir 22. While the charge of air in the cylinder is still undergoing compression, the rocker 28 is actuated whereby the plunger 11 is forced inwardly in opposition to its spring 25. This inward stroke'of the plunger causes its inner end to lap and thus close the ports 24, whereby communication between the compressing chamber 13 and the combustion chamber of the engine cylinder is cut off, and as the in-stroke of the plunger con- .tinues, the body of compressed air which is trapped in the compressing chamber 13 by the closing of the ports 24 is compressed to a degree much higher than the coin ression pressure existing in the engine cylinder, and this compressed air is forced out of the chamber '13 and through the passageway 16 iii all

till

de i

into communication withthe ports 24:, and,

in consequence, the highly compressed charge of fuel contained in the reservoir 22 is quickly and forcibly discharged from the .reservoir 22 through the ports 24 and into the combustion chamber of the cylinder to mix therein with the charge of compressed air and form therewith the explosive charge which may be ignited spontaneously by its compression, or by a spark plug or ignition device, or in any suitable or well-known way.

Following the discharge of fuel into the combustion chamber of the' cylinder, the rocker 28 retracts to allow the spring 25 to return the plunger 11 to its normal or outer position and the injector isthen in condition to repeat the cycle of operations just described.

Fig. 5 shows in full lines, substantially the position of the plunger when the fuel vapor is injected or discharged into the engine cylinder, the lower or inner edge or shoulder 22 of the vapor reservoir 22 then being at a level below the upper or outer edges of the radial orifices 24 so that the fuel vapor may discharge into and through said orifices into the combustion chamber of the engine. By appropriately proport oning the size of the orifices in relation to the limit of inward movement of 'the plunger, it may be arranged that the edge 22* of the plunger will only partially uncover the orifices to effect the injection of fuel into the enginecylinder, in consequence of which the fuel will be injected at high velocity under a pressure much higher than the compression pressure existing within the engine cylinder. thus insuring its complete atomizatlon and rapid introduction into the cylinder, and-its thorough mixing and dis tribution throughout the body of compressed air contained at this time in the engine cylinder so that a rapidly-burnin and highly-explosive charge is produce and moreover, the orifices 24 may be made relatively large in size and, if desired, flared at their outer ends, substantially as shown, with the advantages that compressed air from the engine cylinder is freely admitted to the compression chamber 13 and clogging of these orifices, due to accumulation of heavy portions of the fuel oil or sediment therein, carbonizing of the fuel at these points, or other causes, is avoided or reduced to a minimum, andcleaning of these orifices, if such should become necessary, maybe accomplished easily. As these fuel injection orifices are located at the upper edge of the compressing chamber 13 and are distributed around the circumference of the injector, there is no opportunity for liquid oil to drain and settle in these orifices and become carbonized, and the radial arrangement of the orifices enables them to project the fuel vapor in a plurality of drectio'ns against the side walls of the combustion chamber. It will be understood that the fuel vapor in the reservoir 22 is prevented from discharging therefrom through the orifices 2 1, during the compressing stroke of the plunger, as the portion of the plunger below the reservoir 22 then laps and closes these orifices, although transfer of fuel compressed in the chamber 13 into the reservoir 22 may take place during the compressing stroke of the plunger, as communication is maintained between chamber 13 and reservoir 22 by the passageway 16 and the port 21. Consequently, the fuel is not released for injection into the engine cylinder until the plunger has reached the end of its coniprcssing stroke, at which time the fuel will be comprcssedto a very high pressure. By forming-the lower end of the chamber 13 of conical form, any liquid fuel in this chamber will drain into the passageway-16 for transfer to the rescrvofr 22, and by forming the lower or inner end 15 of the plunger of corresponding form, not only is high compression of the fuel obtainable but the sloping surfaces of the plunger act as deflectors for the air which rushes into the chamber 13 from the engine cylinder througlr the orifices 24 when the plunger is at the upper or outer end of its stroke as shown in Fig. 2. the a r so introduced mixing readily with liquid fuel in the lower portion of the passageway 16 or the lower portion of the reservoir 22.

I claim as my invention;-

1. A fuel injector for internal combustion engines comprising an injector body adapted for insertion into the cylinder of the engine and having an air con'ipression chamber, a fuel reservoir, a fuel passageway having means for supplying fuel thereto and through which air passes from the compression chamber to the reservoir. orifices being formed in the injector body and adapted to communicate with said compression cham ber or said reservoir, and means operative to compress air in said chamber and to control the communication of said chamber and reservoir with said orifices.

2. A fuel injector for internal combustion engines comprising an injector body adapted for insertion into the cylinder of 1 comprising chamber, a fuel reservoir,

. said .tive to control the the-engine and having an air compression a fuel passageway extending from said compression chamber to said reservoir, and having means for-sup.- plying fuel thereto, fuel injection orifices being formed in the injector body and adapted to provide outlets for said reservoir, and means operative to compress air in said compression chamber and to control communication between thefuel reservoir and said fuel injection orifices.

3. A fuel injector for internal combustion engines comprising an injector body adapted for insertion into the cylinder of the engine and having an air compression chamber. a fuel reservoir, :1 fuel passageway connecting chamber and reservoir and having means for supplying fuel thereto, orifices being formed in the injector body for admitting air to said chamber and discharging fuel from said reservoir, and means operaadmission of air from the engine cylinder to said chamber through said orifices, to compress air in said chamber and force it through sa'd fuel passageway into'the reservoir, and to cause injection of fuel from the reservoir through said orifices into. the engine cylinder.

A fuel injector for internal combustion engines comprising an ejector body adapted for insertion into an engine cylinder and having a compression chamber and orifices to establish communication between it and the combustion chamber of the cylinder, and having a fuel supply, passageway communi-- eating with said compression chamber, a reservoir to receive fuel and air from said compression chamber and passageway, and means operative to pression chamber throughsaid orifices from the engine cylinder and transfer it together with fuel through said passageway into said reservoir, to compress such air in said chamber and reservoir, and to discharge the compressed air and fuel into the engine cylinder.

5. Aninjeetor of the character described compression chamber having orifices communicating with the side thereof and a fuel supply passageway communicating with an end thereof, and a plunger having a portion operative in said chamber to uncover said orifices and thus admit fluid to said chamber and to close said orifices and compress such fluid in said chamber, the plunger being recessed to form a reservoir to receive compressed fluid and fuel from-said passageway,

admit air to said com-- an injector body formed with a the plunger being operative to bring said reservoir into communication with said orifices.

6. An injector of the character described comprising a body having a compressing chamber therein, orifices to establish communication between the sides of said chamber and the exterior of the body, and a fuel supply passageway communicating with the end of said chamber, and a plunger rccipr cable in the body and having a portion operative to uncover and'cover said orifices and to produce a compression of air in said chamber, the plunger having a reservoir which communicates with said passageway to receive air and fuel therefrom and is adapted to be brought into communication with said orifices.

7 An injector of the character described comprising a body having an aircompression chamber therein and having orifices inthe sides of said chamber and also having a fuel passageway communicating therewith, and a plunger reciprocable in the body and having a portion movable past said orifices to uncover and cover them and to compress air admitted to said chamber through said orifices, the plunger being grooved peripherally to form a reservoir which communicates with said fuel passageway, the plunger being operative, at the end of its compression stroke, to carry an edge of the peripheral groove therein partially across said orifices and thus form restricted outlets for the discharge of fuel and air from the reservoir.

8. A fuel injector of the character described comprising a body having an air compression chamber therein and having orifices in the sides thereof for admitting air thereto and a fuel passageway communicating with an end thereof, and a plunger reciprocable in the body and having a portion arranged to uncover and cover said orifices and operative to produce a compression of air in said chamber, the plunger being grooved circumferentially to form a fuel reservoir which comrnuicates with said passageway to receive fuel and compressed air therefrom, the plunger being operative, at the end of its compression stroke, to bring an edge of the groove therein across said orifices and thus cause discharge of fuel and compressed air from the reservoir at high velocity through said orifices.

In testimony whereof I have hereunto set in hand.

y JOHN W. EN RIGHT.

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