US3460760A

US3460760A - Fuel injection nozzle assembly

Info

Publication number: US3460760A
Application number: US646258A
Authority: US
Inventors: Elmer Bluhm
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1967-06-15
Filing date: 1967-06-15
Publication date: 1969-08-12
Anticipated expiration: 1986-08-12

Description

E. BLUHM FUEL INJECTION NOZZLE ASSEMBLY Filed June 15, 1967 0 M w w m k n k k v T N w .Vma. W 1 an .MWW$& w

E/zzzer 5/11/2122 A TTORNE Y r f /Z f l f f VKKf/ffl Ill/f Aug. 12, 1969 United States Patent 3,460,760 FUEL INJECTION NOZZLE ASSEMBLY Elmer Bluhm, Grandville, Micl1., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed June 15, 1967, Ser. No. 646,258 Int. Cl. Bb 15/00, N30

US. Cl. 239-1323 4 Claims ABSTRACT OF THE DISCLOSURE A cooled fuel injection nozzle assembly provides a holder and abutting nozzle, the latter having a central needle valve and fuel receiving chamber. Oppositely disposed duel delivery ducts in the nozzle supply fuel to opposite sides of said chamber and connect through a semiarcuate duct between the nozzle and holder with a single supply duct in the holder. Coolant passages in the nozzle are connected with inlet and outlet ducts passing through hollow dowels in the holder and nozzle. The dowels are angularly spaced from the delivery ducts and index the nozzle and holder to properly locate their connecting ducts.

The invention herein described was made in the course of work under a contract or subcontract thereunder with the Department of Defense. This invention relates to fuel injection nozzles for internal combustion engines and more particularly to a cooled fuel injection nozzle assembly of compact size and improved construction.

In the design of cooled fuel injection nozzles of the present type, it is necesary to provide several fluid conducting passages between the spray nozzle and its holder to provide for delivery of fuel to the delivery valve as well as for the supply to and discharge of cooling fuel from the nozzle tip. In order to provide a compact nozzle assembly, these passages may extend through the annular abutting surfaces of the nozzle and holder which surround the centrally located needle valve and its associted components. A locating dowel is generally used to properly locate the holder and nozzle passages. This arrangement requires several connecting holes in the abutting ends of the holder and nozzle and has led to the use in some nozzles of a single high-pressure fuel supply duct in the nozzle for supplying fuel to the fuel receiving chamber surrounding the needle valve. Such an arrangement has been found to result in excessive rates of fuel flow into the chamber leading to erosion within the nozzle as well as flow limitation due to unbalanced flow into the chamber.

The present invention provides a compact cooled injection nozzle assembly in which dual delivery ducts are utilized in the nozzle so as to supply fuel in a balanced manner to opposite sides of the fuel receiving chamber. The duel ducts are connected by a semiannular duct formed between the holder and nozzle and which is supplied by a single larger duct in the holder. Coolant inlet and outlet passages extend through the abutting surfaces of the holder and nozzle at points angularly spaced from each other and from the semiannular duct and these pass through a pair of hollow dowels which extend between the holder and nozzle and properly index them to correctly locate the various connecting passages. This construction, by combining the coolant passages and locating dowel openings, reduces the number of holes needed in the nozzle end and provides a compact nozzle assembly having desirable fuel distribution and coolant flow characteristics as well as other advantages which will be apparent from the following description of a preferred embodiment in which:

FIGURE 1 is a longitudinal cross-sectional view of a fuel injection nozzle assembly arranged according to the invention, the view being taken generally in the plane indicated by the line 11 of FIGURE 2;

FIGURE 2 is a lateral cross-sectional view taken generally in the plane indicated by the line 22 of FIG- URE 1 at the location of certain nozzle fuel connections;

FIGURE 3 is a fragmentary longitudinal cross-sectional view taken generally in the planes indicated by the line 3-3 of FIGURE 2 and showing portions of the inlet and outlet coolant ducts.

FIGURE 4 is a lateral cross-sectional view taken generally in the plane indicated by the line 4-4 of FIG- URE 1 and showing the nozzle abutting surface of the holder;

FIGURE 5 is a lateral cross-sectional view taken generally in the plane indicated by the line 5-5 of FIG- URE 1 and showing the holder abutting surface of the nozzle;

FIGURE 6 is a fragmentary longitudinal cross-sectional view taken generally in the plane indicated by the line 6-6 of FIGURE 5 and showing portions of the fuel delivery ducts and coolant passages; and

FIGURE 7 is a transverse cross-sectional view taken generally in the plane indicated by the line: 7-7 of FIG- URE l and showing portions of the coolant passages.

Referring more specifically to the drawings numeral 10 generally indicates a fuel injection nozzle assembly arranged according to the invention. Nozzle assembly 10 includes a nozzle holder 12 having a lower end 14 which abuts the upper end 16 of an injection or spray nozzle 18 which is secured against the holder by a cap nut 20.

Holder 12 includes a central bore 22 which extends through a smaller opening 24 to lower end 14. Bore 22 connects at its upper end with an enlarged compartment 26 which connects with an internally threaded connection 28. Coil spring means 30 are seated in compartment 26 and urge downwardly a rod 34 disposed in bore 22. Chamber 26 is also connected with the lower end 14 of the holder by a drilled passage or duct 36 (FIGURES 24) for a purpose to be subsequently described. A second internally threaded connector 38 extends from one side of holder 12 and connects through drilled passages or ducts 40 and 42 with the lower end 14. Opposite connector 38 is an externally threaded high pressure connector 44 which connects through passages or

ducts

46 and 48 with the lower end 14.

Spray nozzle 18 includes a central bore: 50 having an upper diameter 52 larger than its lower diameter 54 and terminating in a tapered seat 56 adjacent an orificed spray tip 58. An enlarged fuel receiving chamber 60 is formed intermediate the upper and lower bore diameters 52 and 54. Bore 50 receives a needle valve 62 which is closely fitted to the upper diameter 52 of the bore for reciprocation therein along a longitudinal axis 63. The needle valve includes a reduced lower portion 64 which extends with substantial clearance through the lower bore diameter 54 seating against seat 56 to normally prevent flow from chamber 60 through spray tip 58. The upper end of needle valve 62 extends through opening 24 into engagement with rod 34 such that the bias of spring 30 normally holds valve 62 against the seat 56.

On its upper end 16, the nozzle has a semiarcuate groove 65 which is centered on the axis 63 and cooperates with the lower end 14 of the holder to form a semiannular duct 66 which connects intermediate its ends with duct 48 of the holder. A pair of fuel delivery ducts 70 extend in the nozzle from opposite ends of duct 66 to opposite edges of chamber 60 for the delivery of fuel to the opposite sides of the chamber.

Coolant passages are formed in part by a pair of hollow dowels 72 which are received in counterbored portions of ducts 42 and 36 of the holder 12 as well as mating counterbored portions of the nozzle 18. The passages extend through dowels 72, one of which connects duct 42 with an inlet duct 74 in the nozzle while the other connects duct 42 with an inlet duct 74 in the nozzle while the other connects duct 36 with a nozzle outlet duct 76. The lower end of nozzle 18 is of reduced diameter and includes a flanged sleeve 78 which is brazed at its lower and upper extremities to the nozzle body 79. The sleeve cooperates with the nozzle body 79 to enclose interconnecting coolant passages connecting with inlet and

outlet ducts

74, 76 and formed by an annular groove 80 located adjacent the spray tip, a pair of opposed flats 82 extending along opposite sides of body 79 and a pair of segmental recesses 84.

In operation, high-pressure fuel is supplied through connector 44 and

ducts

46, 48 to semiannular duct 66 thence through ducts 70 to chamber 60. Pressure in chamber 60 acts upon needle valve 62 opening the valve at a predetermined pressure to permit the flow of fuel from chamber 60 through lower bore diameter 54 and out spray tip 58 in a conventional manner. Fuel leakage through the upper bore diameter 52 passes through opening 24 and bore 22 to chamber 26 and out through con nector 28.

Cooling of the nozzle tip is accomplished by low pressure cooling fuel supplied to the nozzle through connector 38 and ducts 40 and 42 and passing through the hollow center of one of the dowels 72 and through the connecting duct 74 to the nozzle coolant passage formed by one of the segmental recesses 84. From the recess 84 the cooling fuel is directed along one of the flats 82 to annular groove 86) which conducts the fuel in either direction around the end portion of the nozzle cooling it. The cooling fuel then is directed out through the second of the flats 82 and the second of the recesses 84 to outlet passage 76, through the second of the dowels 72 and through duct 36 to chamber 26 in the holder from whence it passes out through connector 28.

While the various features of the present invention have been illustrated by reference to a preferred embodiment, it should be apparent that certain changes might be made without departing from the spirit and scope of the inventive concepts disclosed.

I claim:

1. A fuel injection nozzle assembly for an internal combustion engine, said assembly including a nozzle holder having a plurality of fuel connections,

a spray nozzle sealingly abutting one end of said holder and having a spray tip spaced from said holder,

an enlarged fuel receiving chamber in said nozzle intermediate said spray tip and said holder,

fuel delivery means extending longitudinally through said chamber and connecting said chamber and spray tip, said means being responsive at least in part to fuel pressure in said chamber to control fuel flow from said chamber to said spray tip, said delivery means having a longitudinal axis,

coolant passages in said nozzle and at least partially surrounding said fuel delivery means intermediate said chamber and said spray tip,

a plurality of fluid conducting passages extending through the abutting portions of said nozzle and holder and connecting said nozzle chamber and coolant passages respectively with said holder fuel connections, and the improvement comprising at least one hollow dowel extending into and indexing said holder and nozzle through their abutting portions to properly locate the connecting portions of said fluid conducting passages, one of said passages extending through the hollow center of said dowel whereby said dowel defines a portion of said one passage,

said fluid conducting passages including high pressure fuel ducts connecting one of said fuel connections with said nozzle chamber and said high pressure fuel ducts including a delivery duct in said holder spaced from said axis,

a semiannular duct defined by said holder and said nozzle, said semiannular duct being centered on said axis and terminating on opposite sides thereof, said delivery duct connecting with the semiannular duct intermediate its ends, and

a pair of delivery ducts in said nozzle disposed on opposite sides of said fuel delivery means and connecting said fuel receiving chamber with opposite ends of said semi-annular duct,

said hollow dowel being angularly spaced from said high pressure ducts and defining a passage other than. one of said high pressure ducts.

2. A fuel injection nozzle assembly for an internal combustion engine, said assembly including a nozzle holder having a plurality of fuel connections,

said fluid conducting passages including high pressure fuel ducts occupying adjacent the abutting surfaces of said holder and nozzle approximately half the angular distance surrounding said axis and coolant distribution ducts including inlet and outlet ducts connecting certain of said fuel connections with said nozzle coolant passages, said inlet and outlet ducts passing through the abutting surfaces of said holder and nozzle at points angularly spaced from one another and from said high pressure fuel ducts, said hollow dowel forming a part of and defining one of said inlet and outlet ducts.

3. The assembly of claim 2 and further comprising a second hollow dowel extending into and indexing said holder and nozzle, said second dowel forming a part of and defining the other of said inlet and outlet ducts.

4. A fuel injection nozzle assembly for an internal combustion engine, said assembly including a nozzle holder having a plurality of fuel connections,

coolant passages in said nozzle and at least partially surounding said fuel delivery means intermediate said chamber and said spray tip,

a plurality of fluid conducting passages extending ducts passing through the abutting surfaces of said holder and nozzle at points angularly spaced from one another and from said high pressure fuel ducts and a pair of hollow dowels extending between and indexing said holder and nozzle to properly locate their connecting ducts, said inlet and outlet ducts each extending through the hollow center of one of said dowels, whereby said dowels each define a portion high pressure fuel ducts connecting one of said fuel con- 10 f one f i i l and Outlat m nections with said nozzle chamber and including a delivery duct in said holder spaced from said axis, a semicircular duct defined by said holder and said nozzle, said semiannular duct being centered on said References Cited UNITED STATES PATENTS axis and terminating on opposite sides thereof, said 15 1,879,985 9/1932 Lummen 239 533 delivery duct connecting with the semiannular duct 2,108,547 2/1933 Broeze 239 533 intermediate its ends, and a pair of delivery ducts in 2 8 014 5 1959 Konrad et 1 239 132 5 said nozzle disposed on opposite sides of said fuel delivery means and connecting said fuel receiving FOREIGN PATENTS chamber with opposite ends of said semiannular duct, 20 441 181 1/1936 Great Britain coolant distribution ducts including inlet and outlet ducts connecting others of said fuel connections with said nozzle coolant passages, siad inlet and outlet EVERETT KIRBY Primary Examlmr