US2983491A - Fuel injection system - Google Patents

Description

I May 9, 1961 R. J. POWELL ErAL- FUEL INJECTION SYSTEM Filed Nov. 13, 1958 Sheets-Sheet 1 FIGJ.

INVENTOR S. ROBERT J. POWELL JAMES E. CHAMPION A ORNEYS May 9, 1961 R. J. POWELL EIAL FUEL INJECTION SYSTEM 2 Sheets-Sheet 2 Filed Nov. 13, 1958 FIG.6.

INVENTORS ROBERT J. POWELL JAMES E. CHAMPION BY da m-r ATT NEYS 2,983,491 7 FUEL INJECTION SYSTEM Robert J. Powell and James Champion, Musk'egon, Mich., assignors to Continental Motors Corporatlon, Muskegon, Mich., a corporation of Virgi i 7 Filed Nov. 13, 1953, Sen NOJM, '1 wh -i (cl- 2. 1 m

tes .Pfl

tion systems havingfuelinjectionnozzles' connected with theindividual cylinder air intakes of the engine to provide acontinuous injection of fuel under pressure various difliculties are "encountered. At idle= engine operabio-n, the decreased manifold pressure tends to draw fuel from'the pipes leading to the injection nozzles, as well as increasing the tendency of fueltoboil in the distribution lines due tothe low pressure. Consequently, upon advancing the throttle, fuel is not immediately available .at; sufii'cient pressure to ensure the desired immediate en- 2,983,491 Patented May 9, 1961 tion', illustrating another preferred type of fuel injection Fig. 7 is a cross-sectional view taken substantially on the line 77 of Fig. 5, and a Fig. 8 is a cross-sectional view taken substantially on the line 8-8 of Fig. 5. v g 7 A multi-eylinder internal combustionengine 10 is diagrammatically illustrated in Fig. 1 as having engin'ecylinders 11 provided with cylinder'air intake structures or branch ducts 12. An air intake manifold structure 13 conducts to the intake branch ducts 12(from a throttle intake structure 14 having an adjustablethrottle air valve 15. In some engines, a, conventional-supercharger 16 may be included- The continuous flow fuel injection system-comprises a'fuel tank 20, a fuel pump 21, a fuel injection meter ing valve 22 preferably controlled. through linkage..23 from the throttle valve 15, and a fuel delivery manifold 24. Fuel pipes 25a, 25b and 25c preferably connect respectively'the tank 20, the pump 21, the metering valve 22,- and the fuel delivery manifold 24. I igine response. 'Uti-lization of complex controls and noz- I i zles to overcome this defect. only serves to increase the cost of the system and increases the cost of maintenance and servicing. Also, 'it is foundthat' with such. systems, effective fuel atomization is difiicult to achieve since the fuel travels a relatively short distance tothe cylinder intake'valve. 1

An object of the present invention is to improve performance of internal combustion engines'util-izing fuel injection by providing a simplified and improved fuel injection'nozzle construction. 1

--Anotherrobject of the invention is to eliminate the aforesaid fuel line depletion of idlingoperation by constructing a fuel injection nozzle having an aii inlet to the fuel discharge passage provided witha simplified ductshield. i 3

A further object of the invention is to provide an improved fuel injection noule by constructing-"a casing having a fuel; dischargepassage' vented tdatmoSphre and an individual removable-fuel jet intak'e elementJ fi' Yet a further object'of the invention is to iniprove continuous flo'w fuelinjection system eificiencyby pro- 'viding an improved nozzle automatically operable to dis- "charge an aerated fuel stream into' the cylinder. intake Q d S- l ,1, I. o For a more complete understanding "o f this in ntion, reference may be made to thje accompanying 'diiawings i u n P e r .en si iin efstth -intents in which like reference characters .Yrefer tO. like parts throughout the several.view,s and in which i" Fig. lisa diagrammaticrepresentationof a prefei'r ed present-invention: -=& i Fig; .2- is an elevational viewzpartially =1 scrosses'ect'ion,

.illus'tratingione preferred typeof fuelinjectionnozzl'e'r .Fig. 3 is ainozzle'end 'vieWJof the{injection nozzle l' f-FigZZ asseen from tlieilinet3 3'." E :Fig .'14is: across-sectional 'thei1ine 4- -4'of'Figb-2; s Fig 5 is an elevational [Fuel delivery lines 25 connect the fuel deliverymani fold 24 with fuel injection nozzles 26 mounted on the .cylinderair intake branch ducts 12 and adapted to'ina casing structure 28'including a nozzle member 29 adapted for connection into the cylinder air intake 12. A discharge passage 30' extends longitudinally through the casing structure 28 and has an enlarged chamber portion 31 at its inner end. An individual fuel intake jet member 32 is screw threaded as at 33into the chant- ,berp31, and is provided with a smaller diameter portion '34, which, when disposed in the chamber 31 with its endclosely adjacent'the inner end of the passage 30, converts the chamber 31 into. an elongated annular passage. A fuel 'jet intake passage 35extends longitudinally' through the member 32 and has a-restricted. jetpassage 36 near its inner end. The end'of the ing opposite the nozzle member 29 is threaded as at"37 for connection with the fuel line 25. The intakepas- .sage v.v5gisaxially aligned with the discharge passage 30 so that a continuous flow of fuel, supplied under pressure from the fuel delivery manifold'24 will=be=injected directly through the passage 30 into the cylinder air' intake branch duct 12; i s Thefouter .side' of the'casing 28 is providedwith an annular recess 40, and is open to -atmosphere. Aphirality of radial passages 41 connect this recess 40 with the chamberBiL:

t In, operation, when the engine is idling and manifold pressure drops below atmospheric pressure, instead of sucking fuel from the fuel intake passage 35'arid "the fuel line 25 connected to thecasing -28,- air will be drawn throughthei passages 41 and rthechamber iil into the fuel discharge-passage 30. I For best operation; it hasbeenfound'that the preferred diameter of the discharge passage 30 should" be *appro iifm'ately- 1 /2 "to times the diameter ofjithe fsinallest part the fuel inlet -pa'sjsage"'3 5; tha't is'j the icte'd Q jet passage 36. *The fuel jet mare-amnes a; I I I removed for ease in cleaning the fuel injectionnozZIe 5.;

'Of the idle air requirements of the engine.

.the cylinders. are increased, fuel delivery is also increased. The moment fuel velocity from the passage 36 exceeds the concentric with and spaced from the screen 45.

:3 Also, the" passage 30 should be relatively long, preferably ments, so-as not to upset the normal functioning of the air induction system. During engine-idle operation, with low manifold pressures on the order of about 12" Hg the fuel flow reduced to a minimum, admission of air into the passages 41 at substantially atmospheric pressure supplies part Inasmuch as the air flow through the passages 41 can more than satisfy the demands of the passage 30, the passage 36 remains at substantially atmospheric pressure, thus preventing the low manifold pressure from causing a boiling effect in the fuel lines or from'drawing excess fuel into As engine power and manifold pressure free velocity in the passage 30, the fuel injected into the passage 30 produces a jet siphon effect, drawing in more air through the passages 41, due to a suction formed by the fuel passing from the passage 36 into the passage 30.

This reduction of pressure drawing in air produces an atomization of the fuel in the relatively long discharge passage 30 prior to injection into the air induction manifold. In effect, continuously aerating the fuel stream augments induction air flow and facilitates easier and more rapid fuel vaporization than is possible where fuel is injected directly in a continuous stream into the manifold. The various cross-sectional areas of the fuel intake duct 36, the discharge passage 30, and the air intake passages 41 are predetermined by the size and requirements' of the particular engine with which the nozzles are used, and cooperate to produce the continuous siphon ing and atomization effects described above.

A cylindrical air cleaner screen 45 is arranged to be slipped over the casing 28 to entirely enclose the recess 40, and a cylindrical dust shield element 46 is disposed The .dust shield is open only at the one end, as at 47, which is farthest removed from the passages 4-1 opening from the recess 40 to provide a tortuous passage for the The type of injection nozzle 27 may not be desirable with supercharged engines, because at engine speeds above idling, manifold pressure may rise above atmospheric pressure, causing fuel and air to be exhausted out the air inlet passages 41. For supercharged engines, therefore, a fuel injection nozzle 26 is preferably provided, as illustrated in Figs. through 8.

Inthe nozzle 26, the casing structure 28, the nozzle member 29, the discharge passage 36, the chamber portion 31, the fuel intake jet'member 32 having the smaller diameter portion34, the fuel jet intake passage 35, the

restricted jet passage 36, the annular recess -40, and the radialpassages 41, are all identical in construction and operation with the like parts described in connection with p the injection nozzle 27 of Figs. 2 through 4.

However, a second casing section 50 is disposed on the casing structure 28 to provide a closed annular air chamber 51. A check valve structure 52 is mounted on the casing section 50 and communicates with the air chamber 51 through a radially extending port 53. The

check valve structure 52 comprises a ball check valve 54 adapted to be held against an annular seal 55' by .a relatively weak spring 56. Thus,;in engine operationwhen manifoldpressure ex- Iceeds atmospheric pressure due to' supercharger operafuel stream.

3 5jand to augment air flow by continuously aerating the i check valve structure 52, to provide a tortuous passage for the entering air.

Although we have described only two embodiments of the invention, it will be apparent to one skilled in the art to which the invention pertainsthat various changes and modifications may be made therein without departing from the spirit of the invention or the scope of the ap pended claims.

This application is a continuation-inpart of our copending application Serial No. 634,536, filed Jan. 16, 19-57, for Fuel Injection System, now abandoned.

We claim:

1. In a continuous flow fuel injection system for a multi-cylinder internal combustion engine having a cylinder air intake and an air manifold structure provided with a throttle valve and branch ducts connecting said manifold with said cylinders, integral fuel injection nozzles each comprising a casing structure removably mounted on one of said air intake manifold branch ducts, said casing structure having a fuel discharge passage provided with an outer end port opening directly inot said branch duct, a fuel jet member removably secured in said casing structure and having a fuel jet intake duct openly connected with the inner end of said fuel discharge passages, means supplying a continuous flow of liquid metered fuel under pressureto said fuel jet intake duct, said casing structure having an air inlet means connecting said discharge passage with atmosphere, said fuel jet intake duct and said fuel discharge passage cooperating when fuel pressure exceeds manifold air pressure-to continuously siphon air from said air inlet means into said discharge passage by reason of fuel flow from said fuel jet intake duct into said discharge passage, and said fuel jet intake duct and fuel discharge passage being constructed and arranged to aerate the fuel stream within said fuel discharge passage.

2. In a continuous fiow fuel injection system for a multi-cylinder internal combustion engine having a cylinder air intake and an air manifold structure provided with a throttle valve and branch ducts connecting said manifold with said cylinders, integral fuel injection nozzles each comprising a casing structure removably mounted on one of said air intake manifold branch ducts, said casing structure having a fuel discharge passage provided with an outer end port opening directly into said, branch duct, a fuel jet member removably secured in said casing and having a fuel jet intake duct liquid metered fuel under pressure to said fuel jet intake duct, said casing st-ructurehaving an air inlet means connecting said discharge passage with atmosphere, said fuel jet intake duct, and said, fuel discharge passage cooperating when fuel pressure exceeds manifold air pres sure to continuously siphon air from said air inlet means into said discharge passage by reason of fuel flow from said fuel jet intake duct. into said discharge passage,

and said fuel jet intake duct and fuel' discharge pas-.

sage being constructed and arranged to aerate the fuel stream within said fuel discharge passage,'said fuel jet intake duct being axially aligned with said fuel discharge passage and provided with 1 afrestricted jet opening ad:

jacent the end opening into said fuel discharge passage. '3.-In a continuous fiow fuel injection system forrhulticylinder. internal combustion engines having a cylinder air intake and an air'indu'ction. system including an. air intake manifold structure provided with a throttle valve and branch ducts jconnectingfsaidi manifold with said cylinders, integral fuel injection nozzles ;each comprisin in tructu re qvabhrme nted 'on one of.

'said air intake manifold-branch ducts and having a fuel dischargeipassage provided with an outer cnd port opening directly into said branch duct, said casing structure having an enlarged chamber openly connected with the inner end of said fuel discharge passage, a fuel jet member removably secured in said casing and extending into saidchamber to forman annular space surrounding a p'ortionof saidfuel jet member, said fuel jet member having' afuel jet intake duct directly openlyconnected with said chamber adjacent and axially spaced from the'inner-end of said fuel discharge passage, means supplying a continuous flow of liquid metered fuel'under pressure to said fuel jet intake duct, said'casing' structure having an air inlet means openly connecting said annular space with atmosphere, said fuel jet intake duct and said fuel discharge passage cooperating when fuel pressure exceeds manifold air pressure to continuously siphon air from said annular space into said discharge passage by reason of fuel flow from said fuel jet intake duct into said discharge passage at engine speeds above idling, said fuel jet intake duct and said fuel discharge passage being constructed and arranged: to aerate the fuel stream within said discharge passage.

4. In a continuous flow fuel injection system for a multi-cylinder combustion engine having a cylinder air intake and an air induction system including valve and branch ducts connecting said manifold with said cylin-- ders, integral fuel injection nozzles each comprising a casing structure removably mounted on one of said air intake manifold branch ducts and having a fuel discharge passage provided with an outer end port opening directly into said branch duct, said casing structure having an enlarged chamber openly connected with the inner end of said fuel discharge passage, a fuel jet member removably'secured in said casing and extending into said said annular space into said discharge passage by reason' of fuel flow from said fuel jet intake duct into said discharge passage at engine speeds above idling, said fuel jet intake duct and said fuel discharge passage being constructed and arranged to aerate the fuel stream within said discharge passage, said air inlet means comprising an air passage openly connectedto atmosphere and to said annular space at a location upstream of saidfuel jet intake duct connection with said chamber.

5. In a continuous flow fuel injection system, for a multi-cylinder combustion engine having a cylinder air intake and an air induction system including valve and shield element having an air inlet opening adjacent the Y discharge passage cooperatiri'g when fuel prssrireiexceeds manifoldfair pressure to continuously siphon air from said annularspace into said discharge passage by reason'of' fuel flow from said fuel jetintake duct into said discharge passage 'at engine speeds above idling, said fuel jet intake duct and said fuel discharge passage being constructed and arranged to aerate the fuel stream within said discharge passage, said air inlet means cornprising'anair passage openly connected to atmosphere and to said annular space at a location upstream of said fuel jet intake duct connection with said chamber, said casing structure having an exterior 'annular air recess openly connected with said airpassage, a screen element enclosing said air recess, and a dust shield element partially enclosing said screen element and constructed to provide a tortuous path for air entering said air passage.

6. In a continuous flow fuel injection system for a multi-cylinder internal combustion engine having a cylinder air intake and an air induction system including an air take manifold structure provided with a throttle valve and branch ducts connecting said manifold with said cylinders, integral fuel injection nozzles each comprising a casing structure removably mounted on one of said air intake manifold branch ducts and having a fuel discharge passage provided with an outer end port opening directly into said branch duct, said casing having an enlarged chamber openly connected with the inner end of said fuel discharge passage, a fuel jet member removably secured in said casing and extending into said chamber to form an annular space surrounding a portion of said fuel jet member, said fuel jet member having a fuel jet intake duct openly connected with said chamber adjacent and axially spaced from the inner end of said fuel discharge passage, means supplying a continuous flow of liquid metered fuel under pressure to said fuel jet intake duct, a casing structure having an air inlet means openly connecting said annular space with atmosphere, said fuel jet intake duct and said fuel discharge passage cooperating when fuel pressure exceeds manifold air pressure to continuously siphon air from said annular space into said discharge passage by reason of fuel flow from said fuel jet intake duct into said discharge passage at engine speeds aboveidling, said fueljet intake duct and said fuel discharge passage being constructed and arranged. to aerate the-fuel stream within said disannular space to one end of said exterior air recess, a

screen element enclosing said'recess and radially spaced therefrom, and a dust shield element radially spaced from and partially enclosing said screen element, said dust other end of said airrecess and offset from saidair inlet branch ducts connecting said manifold with said cylinders, integral fuel injection nozzles each comprising a casing structure removably mounted on one of said air intake manifold branch ducts and having a fuel'disto said fuel jet intake duct, said casing structure having an air inlet means openly connectingsaid annular space with atmosphere, said fuel jet-intake duct and said fuel passages to provide a tortuous path for air entering same.

' 7. In a continuous flow fuel injection system for a multi-cylinder internal combustion engine having a cylinder air intake and anair induction system including an 7 cylinders, integral, fuel injection nozzles each comprising an elongated casing structure-removably mounted on one of said airintake manifold branch ducts and having an elongated fuel discharge passage provided with an having an enlarged bore axially aligned with said dis-- charge passage and having the inner end openly connected with the inner end of said'discharge passage,

7 anda'separate fuel jet member removably, secured in said bore and having an inner reduced diameter portionof.

, smaller diameter than said bore to-provi'de an elongated inner annular space connecting with the inner end of 7 said discharge passage, said fuel jet member having an axially extending fuel intake passage therethrough provided with a restricted venturi jet opening at the inner end, and said casing structure having an air inlet means connecting the elongated annular space with atmosphere, means supplying a continuous flow of liquid metered fuel under pressure to said fuel jet member, said venturi jet opening and said fuel discharge passage cooperating when fuel pressure exceeds manifold air pressure to siphon air from said annular space into said discharge passage by reason of fuel flow from said venturi jet opening into said discharge passage at engine speeds above idling, said venturi jet opening and said fuel discharge passage being constructed and arranged to aerate the fuel stream within said fuel discharge passage.

References Cited in the file of this patent UNITED STATES PATENTS

Images