US2370155A - Fuel injector nozzle - Google Patents

Description

Feb. 27, 1945. O N H 2,370,155

FUEL INJECTOR NOZZLE Filed Oct. 16, 1941 INVENTOR.

Patented Feb. 27, 1945 FUEL INJECTOR NOZZLE Louis 0. French, Milwaukee, Wis.

Application October 16, 1941, Serial No. 415,170

7 Claims.

The spraying of fuel from an ordinary poppet, particularly cone, type check valve has not been found satisfactory because of v the uncontrolled unevenness of its discharge and the high rate of increase of discharge area as the valve is opened. Attempts have been made to modify the action of this type of valve by placing a nozzlemember infront of the valve, this nozzle member either being of the fixed type embodying one or more small holes in a nozzle plate or being of the movable type embodying an extension of the head of the valve which cooperates with part of the valve casing to control the discharge.

With the fixed type nozzle plate, the holes sometimes become clogged with carbon deposits, and in some instances the metal of the nozzle becomes red hot and the holes lose their original fixed dimensions. Either of the above conditions will interfere with the proper metering and delivery of fuel to the combustion chamber of the engine. Where the head of the valve is provided a spray nozzle in which the spray ipassage'sfue disposedsubstantially laterally of the 'valve stem or a circle slightly larger than sald stem d at such an angle of inclination that the in'a'i of each spray clears the seat and also; v above the head of the valve in its open lposi on.

A further object of the invention is to .prdvide an arrangement whereby the valve seat member with a discharge controlling extension, such extension is subjected to the heat of the engine, and due to its heating cannot be too closely associated with the body of the valve without danger of seizing, and the cavities between the extension and the valve body present places for building up carbon deposits that eventually interfere with the free movement of the valve.

The object of the present invention is to provide a spraying means in the valve casing which is not exposed to the direct heat and combustion gases of the engine except only at the time of injection and which is at all other times covered by a check valve which on opening may in some instances form a deflecting surface for fuel sprays issuing through the seat opening from spray openings in the fixed casing of the valve.

A further object of the'invention is to provide an outwardly opening check valve type injector valve type in which the fuel issues through the valve seat, when the valve is open, in the form of visibly segregated finely atomized sprays.

A further object of the invention is to provide a spray nozzle of the outwardly opening check valve type in which the nozzle openings are provided by grooves formed in the end of a separable tubular guide sleeve for the valve and which end may be inclined more or less from a horizontal plane to provide a less or greater angle for the spray jets.

A further object of the invention is to provide is subjected to the direct cooling action pf the jacket water, so that the valveparts willbe prevented from'overheating. a f

A further object of the inventionis MIDI. ide a spray nozzle which is non-dribbling"a nd,.. in which the maintenance of the Spray-Openings is charging fuel from cloggingthese openings;

The invention further consistsinwthe; features hereinafter set forth and more particularly defined by claims at'the conclusion hereof In the drawing: a l s, Fig. 1 is a vertical sectional view of-;a:.device embodyin the invention; I 1; Fig. 2 is a sectional view showing-the :yalve in an open position; v w

Fig. 3 is-an end view of theliner member shown in Fig. 2; 1 Fig. 4 is a detail horizontal sectional view taken on the line 44 of Fig. 2; 1

Fig. 5 is an elevation view of the valve; Fig. 6 is an elevation view of another'liner member, parts broken away and shown in section;

the nozzle 7 member centric bores l3and l4, the upper larger dia'meter bore i3 being threaded and the lowersmall bore l4 being plain andterminating in aconically inclined stop end l5 whose smaller diameter is disposed at the upper or inlet end of an outwardly comically inclined valve seat l6.

The sleeve member I 2 is threaded to engage the threaded bore I3 and has a reduced lower part I l slidably fitting'the bore I4 and having a conical end l8 seating on the end l5 of the main casing part. The member l2 has a centrally disposed valve guide bore I9 and a flat surface 20 atthe outer end of this bore and end la. The upper end of the bore l9 communicates with a wrench sockct cavity 2| similar tothat used on a hollow head set screw.

conical end I8 is provided with a plurality (four or five) equally spaced spray grooves 22 cf 3 relatively shallow depth to form with the end wall 1 18. a series of. fine fuel passages, which are laterallyoil'set from the guide bore l8 and conveniently formed tangent to the outer circle bounding the surface 28 and are also inclinedoutwardly so that the bulk of the spray issuing therefrom will clear the seat I8 and also pass clear of the head of thevalve It in its open position. These pasare supplied with fuel from a space outside the guide bore II by providing flats 28 on the part II connecting said grooves 22 with an annular recess 2| spaced lengthwise from the seat and connected with the bore I! by one or more radial 28. The ends of the spray grooves 22 terminateat the surface portion 20, and when thogs'lceve is screwed into place in the main casing part I I, this portion 28 is disposed at or adjacent the inlet. end of the valve seat It.

The discharge valve ID has an ordinary conical 28 seating on the seat provided by the seat portion l8 and a stem 21 which is slidably mountedz'in the bore l8 and is grooved to cooperate therewith to control the flow of fuel to the spray grpovfu 22. As shown, the stem 21 has an annular conically inclined fuel inlet groove 28. The upper deeper, portion of this groove is connected with the socket 2| by a series of flats 28 formed on said stem. The portion 88 of the stem between thegrooveffl and the head of the valve forms a plain piston which is preferably closely fitted to bore l8, thereby preventing at all times any force on said spring 3|.

l'he casing part II is shown as threaded to receive a cap 88 having an opening. 34 for a suitable fuel supply pipe though it will be noted that this ,valvestructure may be used as the discharge valve oii-a unit injector.

when the valve i8 is in closed position, the lower end of the groove 28 preferably has a lapped relation, for example, one-thirty-second to one-sixteenth of an inch, relative to the passages 28 connected with the spray grooves with the result that the valve I8 is, during the pressure stroke of the injection pump, first moved outwardly against the pressure of the spring 8| until groove .28 registers with said passages 25 and the valve head is spaced from its seat at which time the fuel under pressure then flows from the Kroove 2 8 to passages 28, recess 24, flats 28, and through the spray grooves 22 from which it issues inflne streams as indicated by the arrow in 2 inthe form of widely divergent ilnely atom- 118d sprays which make this form of nozzle suitable for distributing fuel into a relatively fiat head-form of engine combustion chamber.

Furthermore, with the inclined groove 28 the flowof fuel to the spray grooves 2| is gradually increased as the valve ll moves outwardly to the lirhitof its travel which may be determined by any suitable stop means, as for example, the engagement of the nut 82 with the top of the liner It is also to be noted that the width of the seat l8 may in practice be made relatively small, for example, from one-sixty-fourth to one-thirty-sec- 0nd of an inch so that the distance the valve head 26 has to move before it clears the seat I8 and the exposed end of the valve casing is small. The

small flat surface 20 permits the grooves 22 to extend into this surface clear of the inner diameter of the seat l6.

Another form of liner which gives somewhat different spray characteristics is the liner 12 shown in Figs. 6 and '7. This liner is identical with the first described form except at the outer end of the valve guide bore IS a conically inclined surface 34' of the same general slope as that of the seat It is provided and the spray grooves 22' generally similar to the grooves 22, terminate at the outer portion of this surface 34. The valve head for this liner may project in over the inclined surface 34' in the closed position of the valve, but this surface is not relied upon as a sealing surface. It has been found that the sprays produced by such a form are not as divergent as the first described form, and in some instances these sprays striking the head of the valve change the direction of the fuel particles.

Where direct impact of the sprays on the valve is relied upon for fuel distribution, the form shown in Figs. 8 and 9 may be used. The casingpart for this form is the same as the first form, and the liner 35 is of the same general form as the liner l2 except that the spray grooves 36 are straight radially disposed notches formed in the end l8 and discharging into the conically inclined end surface 34" which is similar to the surface 34 and similarly associated with the head 26 of the valve l0.

It is to be noted that the conical head 26 of the valve ID for the liners l2 and 35 preferably extends to the stem diameter to keep down the dead oil space beyond the grooves.

With the form of Fig. 8 when the fuel pressure acts to open and move the valve ill to a position clear of the seat IS, the jets from the grooves 38 pass down through the valve seat opening and strike the inclined seating surface of the valve I0 and are deflected generally radially therefrom, the angle of dispersion of these jets varying with the angular incline of the end i5 and to some extent with the angular incline of the head 26. While the amount of variance of the angle of the head 26 may be through 15 or 20 degrees, the angularity of the end I5 may be varied through widely varying limits to provide different spray distribution patterns.

For cooling the valve the casing part II has direct threaded engagement at its reduced threaded end 31 with a threaded opening in the wall 38 of the cylinder or cylinder head of the internal combustion engine, and the walls of this casing are preferably directly exposed to the cooling water in the engine jacket space 39 whose outer wall 40 is bored out to fit the rounded upper portion ll of the part I l and is also recessed and threaded at 42 to receive a packing gland nut 43 which compresses the packing 84 to form a leak-tight joint at the upper end of the nozzle. At its lower end a gas seal is effected by a suitable soft metal ring 45 clamped between the part II and the shoulder at the upper part of the threaded opening in the wall 38. Thus the part I I which has the valve seat formed in it is in direct contact with the cooled engine walls and the cooling medium itself, so that this will keep this part cool and prevent serious distortion of the valve seat and will keep the valve head in contact therewith cool. The liner part I2, 33, or 35, being completely encased in the part II, will be cooled thereby as well as by the fuel passing through the liner.

I desire it to be understood that this invention is notto be limited to any particular form or arrangement of parts except in so far as such limitations are included in the claims.

What I claim as my invention is:

In a fuel injection nozzle, the combination of a casing having a fuel passage with a valve seat at one end and including a liner member for a part of said passage having spray grooves in one end opening into the outer portion of an annular flat surface on this end of said liner member adjacent the inlet end of said seat and normal to the axis of the passage through said member, an outwardly opening fuel-pressure-operated check valve mounted in said passage and controlling the flow of fuel past said seat and having a stem extending through said liner memher, said spray grooves extending substantially tangentially of the periphery of said annular surface into which they open and so inclining outwardly as to direct fuel sprays therefrom between the end of the casing and the head of the valve in its open position.

2. In a fuel injection nozzle, the combination of a casing having a fuel passage with a valve seat at one end, an outwardly opening fuel-pressure-operated check valve in said fuel passage controlling the flow of fuel past said seat and having a stem, said fuel passage including a plurality of fuel spray passages arranged in the casing to direct the bulk of the fuel charge laterally of the stem of said valve and outwardly through the space between the seat and the open valve clear of the valve head in a predetermined position. and other valve means so controlled relative to the first said valve as to delay the feedin of fuel to said fuel spray passages until the first said valve is in its predetermined open position.

3. In a fuel injection nozzle, the combination of a casing having a fuel passage with a valve seat at one end, an outwardly opening fuel-pressure-operated poppet check valve mounted in said fuel passage and controlling the flow of fuel past said seat, said fuel passage including a plurality of fuel spray passages disposed in said casing ad- ,iacent said seat to discharge their fuel charges through the opening in said seat, and other valve means so controlled relative to the first said valve as to delay the feeding of fuel to said fuel spray assages until the first said valve is in predetermined open position.

4. In a fuel injection nozzle, the combination with a casing having a fuel passage with a valve seat at one end, and an outwardly opening fuel pressure operated check valve mounted in said casing and controlling the flow of fuel past said seat and having a stem extending through a part of said fuel passage, said fuel passage including a guide for the stem of said valve and also including a passage extending through the wall of said guide means which contacts with said stem, and a plurality of fuel spray assages arranged in the casing in laterally spaced relation to the stem of said valve with their inlets communicating with the outlet of said passa e through said wall and their outlets adjacent the valve seat and so directed that discharge therefrom substantially clears the valve stem and clears the valve after the valve has been opened a predetermined amount, said stem being in the form of a piston valve which so cooperates with said passage through the wall of said guide means as to delay the supply of fuel to said spray passages until said valve has been opened said predetermined amount.

5. In a fuel injector nozzle, the combination of a casing having a fuel passage with a valve seat at one end and including a liner member for a part of said passage providing a guide bore for the valve, a passage extending through the wall of said guide bore at some distance back from said seat and spray grooves having their inlets communicating with said passage in said guide bore and their outlets adjacent the valve seat, and an outwardly opening fuel pressure operated check valve controlling the flow of fuel past said seat and having a stem slidably mounted in said guide bore and forming a piston valve which so cooperates with said passage through the wall of said bore as to delay the supply of fuel to said spray passages until said valve has been opened a predetermined amount, said stem substantially filling the lower end of said guide bore in the open position of said valve.

6. 'In a fuel injection nozzle, the combination of a casing having a fuel passage with a valve seat at one end and including a liner member for a part of said passage providing a guide bore for the valve, a passage extending through the wall of said guide bore at some distance back from said seat, and spray grooves having their inlets communicating with said passage through said guide bore and .their outlets adjacent the valve seat, and an outwardly opening fuel pressure operated conically headed check valve mounted in said passage and controlling the flow of fuel past said seat and having a stem slidably mounted in said guide bore and forming a piston valve which so cooperates with said passage through the wall of said bore as to delay the supply of fuel to said spray grooves until said valve has been open a predetermined amount, said stem filling the lower end 01' said guide bore in the 'open position of said valve, said grooves disposed adjacent said seat and positioned to discharge the bulk of their fuel charges laterally of and clear of the stem of said valve and the valve and outwardly through the space between the seat and said valve after it has been opened a predetermined amount.

7. In a fuel injection nozzle, the combination of a casing having a fuel passage with a valve seat at one end and a bore, a sleeve member mounted in said bore and having a, centrally disposed valve guide bore, a passage extending through the wall of said guide bore at a distance back from said seat and a conically inclined portion at one end of said guide bore provided with spray grooves having their inlets communicating with said passage through said guide bore and their outlets adjacent said valve seat for discharging fuel streams through said seat, and an outwardly opening fuel-pressure-operated conically headed check valve mounted in said passage and controlling the flowof fuel past said seat and having a. stem slidably mounted in said guide bore and forming a piston valve having a conically grooved portion adapted to so cooperate with said passage through said guide bore as to delay the supply of fuel to said spray grooves until said valve has been opened a predetermined amount.

LOUIS O. FRENCH.

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