US3363710A - Fuel supply system for an internal combustion engine - Google Patents

Description

C. H. FAGER Jan. 16, 1968 3,363,710 EL SUPPLY SYSTEM FOR AN INTERNAL COMBUSTION ENGINE 1965 Filed July 12,

2 Sheets-Sheet l mvEN'roR. CHARLES H. FA GER ATTORNEYS.

C. H. FAGER Jan. 16, 1968 2 Sheets-Sheet 2 Filed July l2, 1965 INVENTOR. CHARLES H. FAGER ATTORNEYS United States Patent O Filed July 12, 1965, Ser. No. 471,069 S Claims. (Cl. 180-54) ABSTRACT 0F THE DISCLOSURE A fuel injection pump of an internal combustion engine is enclosed within a duct that extends from an air cleaner outside an engine enclosure to the intake manifold of the engine within the engine enclosure. The intake air cools the pump and inhibits vapor lock.

This invention relates to a fuel injection system for an internal lcombustion engine, and more specifically to an arrangement for cooling the fuel pump of a fuel injection system for a motor vehicle, such as a truck.

It is conventional, in fuel injection systems used with internal combustion engines, to locate the fuel injection pump directly above the engine. This arrangement is convenient, because it facilitates driving the fuel pump through a gear arrangement from a cam shaft driven from the crank shaft of the engine or from a timing gear at the rear of the engine. However, such a location is disadvantageous, in that it subjects the fuel injection pump to the direct heat from the engine and also to the flow of relatively hot air that passes first through the radiator and then over the engine. This hot environment often causes the fuel being pumped through the fuel injection pump to vaporize and cause what is known as vapor lock, i.e., an interruption of flow of fuel due to bubbles of vaporized fuel within the pump or fuel line. When this occurs, the pump fails to properly supply fuel to the cylinders of the engine, causing inefficient operation or engine failure.

In accordance with the present invention, a convenient and effective solution to this problem is provided, without the necessity and disadvantages of moving the fuel pump to a different location. This is accomplished by effectively shielding the fuel injection pump from the direct heat of the engine and from the flow of hot air from the radiator and by circulating relatively cool air about the fuel pump, This circulation of cool air is best provided by ducting air from outside the engine enclosure of the motor vehicle and channeling it through a Icooling jacket surrounding the fuel injection pump.

This invention is particularly applicable to heavy duty trucks that normally locate the air lter, through which air is supplied to the lair intake manifold of the engine, on the outside of the engine enclosure. In accordance with this invention, the tiow of cool air from outside the engine enclosure, is circulated around the fuel injection pump. The combination of this air Acirculation and, in the preferred arrangement, the shielding effect of the air duct or cooling jacket about the fuel injection pump effectively maintains the temperature of the fuel injection pump low enough to prevent premature vaporizing of the fuel and the resultant vapor lock.

These and other features and advantages of this invention will be readily appreciated by reference to the following detailed description when considered in connection with the accompanying Vdrawings in which:

FIGURE l is a top plan view of an internal combustion engine and fuel injection system shown within an Cil 3,363,710 Patented Jan. 16, 1968 engine housing and with an the housing;

FIGURE 2 is a partial side elevational view of the engine of FIGURE l, showing in detail the arrangement of the cooling jacket about the fuel injection pump and the air duct from the jacket to an air intake manifold of the engine; and

FIGURE 3 is a partial sectional view taken along the line 3-3 of FIGURE 1 showing the duct system surrounding the fuel injection pump and showing the manner in which the pump is driven.

Referring now to the drawings, there is shown in FIGURE 1 an engine enclosure or hood 10 of a motor vehicle, such as a heavy duty truck. A spark ignited internal combustion engine, indicated generally at 12, is housed within the hood 10. A conventional radiator 14 for the water cooling system of the engine 12 is provided attthe front of the engine. As shown, the engine 12 is of the V-type having angularly disposed cylinder banks 16 and 17, each of which includes four cylinders. An air intake manifold 19 communicates with air intake ports (not shown) of the cylinders in cylinder banks 16 and 17. To this end, the manifold 19 branches into separate passageways 19a-h in direct communication with the intake ports of the cylinders. A plurality of fuel injection nozzles 22a-h are respectively positioned in the passageis adjacent the corresponding air filter intake external to ways 19a-h. Each nozzle inlet port to the cylinder for introducing fuel with the air during operation.

Air is supplied to the air intake manifold 19 from outside the hood 10, through an air filter 25. A duct, indicated generally at 28, carries air from the air lter 25 to an air distribution horn 30 attached above and communicating with a throttle box 32 that is directly above and opens into the manifold 19.

A fuel injection pump 35 is located directly above the engine 12, within the V-formed between the cylinder banks 16 and 17. The pump 35 is adjacent the rear portion of the engine. As best shown in FIGURE 3, the fuel injection pump 35 has a generally cylindrical body 37 extending vertically above the engine 12. A driving or operating shaft 39 extends downward from the pump 35. A pump gear 40 is attached to the shaft 39 and is driven by a helical drive gear 42 keyed to a cam shaft 44. Eight fuel pipes 45u-h are connected to the top of the fuel pump 35 and each communicates with an appropriate one of the fuel injection nozzles 22a-h. iRotation of the drive shaft 39 through the pump gear 40, the helical drive gear 42 and the cam shaft 44 pumps fuel to each cylinder of the engine12 in proper order through the fuel pipes 45u-J1. The proper order is, of course, the firing order of the engine.

As shown in the drawings, the duct, indicated generally at 28, in -communicating -between the air filter 25 and the manifold 19 via the horn 30, passes around, i.e., surrounds, the fuel injection pump 35. To facilitate this, the duct 28 is formed of several parts. A tube or pipe 50 extends from the filter 2S through the wall of the engine enclosure 10 and terminates within the engine enclosure. A corresponding pipe or tube 52 on the opposite side of the engine 12 extends from the air horn 30. A separate section of the duct 28, indicated generally at 55, is located between the two pipes 50` and 52. See FIGURE 3. The duct portion 55 includes a cylindrical housing 56 of larger diameter than the fuel injection pump 35. The housing 56 surrounds the fuel injection pump 35, in spaced relationship thereto and is sealed at the top and bottom of the fuel injection pump by flanges 57 and 58 and associated gaskets that abut lower and upper portions of the fuel injection pump, respectively.

A pipe or tube 60 of similar diameter to the pipe Si) from the air filter extends from the upstanding wall of the cylindrical housing 56 on the side of the fuel pump adjacent the pipe portion 50x The pipe (it)` is coupled to the pipe 50 by a flexible pipe coupling 61. A similar pipe or tube 62 extends from the wall of the housing 56 diametrically opposite from the pipe 60 and is coupled to the conduit section 52 from the horn 30 by a flexible pipe coupling 63.

In operation, it will be understood that as the motor vehicle, such as the truck partially shown in FIGURE l, is operated, the engine 12 becomes relatively hot and the air passing through the radiator 14 becomes heated as it removes heat fr-om the cooling water circulate-d through the radiator and engine. The environment Within the engine enclosure, particularly directly above the engine 12, is therefore considerably hotter than the surrounding environment outside the engine enclosure. With the arrangement above described7 the pump 35 while located in the midst of the hot environment within the engine enclosure, is shielded from the heat of the engine and radiator and is cooled by air circulated from outside the engine enclosure.

Air enters the air filter 25 when the pressure within the manifold 19 is reduced -on an intake cycle of a cylinder of the engine. This air is ultimately introduced to the cylinders via the duct 28, which includes pipes 50 and 60, housing 56, pipes 62 and 52, the air horn 36, the throttle -box 32, and the manifold 19. Along the way, the air passes around the fuel injection pump 35 as it ows within the housing portion 56 of the duct 28. Due to the operation of the motor, this flow of air is continuous and a cool surrounding atmosphere is constantly maintained about the fuel pump 35. This maintains the fue'l injection pump at a considerably lower temperature than the atmosphere within the engine enclosure, and effectively overcomes the tendency of the fuel to prematurely vaporize Within the pump and cause Vapor lock.

While a preferred embodiment of this invention has been disclosed, it will be understood that numerous modications or alterations may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. A fuel injection and air intake system for a truck having an internal combustion engine housed within an engine enclosure, said system comprising a fuel injection pump adapted to be located adjacent the engine within the engine enclosure, an air lter adapted to be located outside the engine enclosure, air intake manifold means adapted to introduce air to separate cylinders of the engine Within the enclosure, and continuous duct means extending from the air filter to the intake manifold means, a portion of said duct means enclosing and surrounding the fuel injection pump in spaced relation therewith, forming a cooling jacket in which air from outside the engine enclosure ows in an enclosed path past the fuel injection pump prior to being introduced into the engine through the air intake manifold means, ywhereby the fuel injection pump is cooled by air drawn into the engine.

2. In a system for injecting motor fuel into the cylinders of an internal combustion engine located within a generally enclosed portion of a motor vehicle, including a fuel injection pump, fuel pipes extending from the pump to cylinders of the engine, gearing means to control the pump, and an air intake manifold for the cylinders of the engine, the improvement which comprises the combination of a spaced jacket surrounding and enclosing the fuel injection pum-p, an air lter located outside the enclosed portion of the vehicle with air duct means from the air lter to the jacket surrounding the pump to carry air from the air lter to the jacket, and air duct means extending from the jacket to carry air from the jacket to the air intake manifold of the engine,

whereby the fuel injection pump is surrounded by the ow of incoming air from outside the engine enclosure going to the intake manifold of the motor vehicle.

3. A cooling system for a fuel injection pump that is located adjacent an internal combustion engine having air intake means and housed within an engine enclosure, said system comprising a housing surrounding and enclosing the fuel injection pump in spaced relationship thereto to provide a cooling jacket of air about the pump, a portion of an air supply duct connecting the housing around the pump to the exterior of the engine enclosure, and a portion of an air supply duct connecting the housing with the air intake means of the engine, whereby a flow of air is established from -outside the engine enclosure, around the fuel injection pump and to the air intake means of the engine.

4. In a fuel injection system, a fuel injection pump of generally cylindrical shape having a predetermined maximum diameter and height, a housing having a generally cylindrical wall of larger diameter than the pump and surrounding the pump in spaced relationship, means sealing the housing and the pump adjacent both ends of the generally cylindrical pump, two air ducts opening through the cylindrical wall of the housing at essentially diametrically opposed locations, the housing thereby forming an enlarged -chamber between the two air ducts and through which a substantial portion of the cylindrical fuel injection pump extends, means connected to one end of the pump external to the housing for supplying fuel to injectors, and gear means extending from the other end of the ypump external to the housing for driving the pump.

5. The system of claim 4 wherein the fuel injection system is located 4within an engine enclosure and wherein one of the air ducts communicates with the atmosphere external to the engine enclosure.

6. In a motor vehicle having an engine closure, an internal combustion engine with the engine enclosure, an air intake manifold on the engine, and an air intake external to the engine enclosure, the combination of an air duct extending within the engine enclosure from the external air intake to the air intake manifold of the engine, and a fuel injection pump located within a portion of the air duct within the engine enclosure.

7. In a motor vehicle having an engine, a radiator, an engine enclosure around the engine and an air intake lter attached to the motor vehicle outside the engine enclosure, the combination of duct means providing an enclosed path for air from the intake filter outside the engine enclosure to an air intake of the engine, and a fuel injection pump supported on the engine within the engine enclosure and located within the duct means so that the how of air to the engine from the air intake filter outside the engine enclosure is channelled directly around the fuel injection pump, thereby cooling the pump with air that has not become heated by the radiator of the motor vehicle.

S. In a motor vehicle, the combination of an engine enclosure, an internal combustion engine within the engine enclosure, an air intake manifold mounted on the engine for introducing air to cylinders of the engine, a radiator mounted in front of the engine at an opening in the engine enclosure, a fuel injection pump mounted above and adjacent the engine Ibehind the radiator, an air filter attached to the vehicle and located outside the engine enclosure, means for ducting air from the air lter to the air intake manifold, said means including a housing that surrounds the fuel injection pump in spaced relationship to provide a cooling jacket therefor, means extending from the pump external to the cooling jacket for supplying fuel to the engine, and gear means also extending from the pump external to the jacket for operating the pump, whereby the pump is cooled by air ducted directly from outside the engine enclosure and is also 5 6 shielded from air within the engine enclosure that has 2,120,779 6/1938 Ericson 123-122 XR been heated by the radiator and engine. 3,160,203 12/ 1964 Kusisto 165-51 References Cited FOREIGN PATENTS UNITED STATES PATENTS 5 771,619 4/ 1957 Great Britain. 1,983,723 12/1934 Wilson. 885,152 12/1961 Great Brltam. 2,033,731 3/1936 Nallinger. 2,066,673 1/1937 131118110111 123-139 BENJAMIN HERSHP'lm'y Exammer' 2,119,379 6/1933 Hoffman et a1. 123411.31 MILTON LSMITREwmweF-

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