US3499607A

US3499607A - Fuel injection valve device

Info

Publication number: US3499607A
Application number: US727253A
Authority: US
Inventors: Millard R Thomson
Original assignee: Bendix Corp
Current assignee: Bendix Corp
Priority date: 1968-05-07
Filing date: 1968-05-07
Publication date: 1970-03-10
Anticipated expiration: 1987-03-10
Also published as: DE1923136A1; DE1923136B2; DE1923136C3; FR2007996A1; GB1258340A

Description

March 10, 1970 R. THQ soN r "Fum- INJECTION VALVE DEvigE;

Filed 'lly" '2, 1968 N am W 0 Y 8 a 2 m M M m /mm m A I. A u M m 0Q m v a a. 5 v lli'd g a a 4 United States Patent 3,499,607 FUEL INJECTION VALVE DEVICE Millard R. Thomson, Sidney, N.Y., assignor to The Bendix Corporation, Sidney, N.Y., a corporation of Delaware Filed May 7, 1968, Ser. No. 727,253

' Int. Cl. 1305b 1/32 US. Cl. 239-533 14 Claims ABSTRACT OFITHE DISCLOSURE "ice the illustrative embodiment of the device of the invention, certain of the parts being shown in elevation;

FIG. 2 is a view similar to FIG. 1 on a greatly enlarged scale of the portion of the device adjacent the nozzle end thereof;

FIG. 3 is a view in end elevation of the main body of the device,-the figure being taken in the direction from right to left in FIGS. 1 and 2; and

FIG. 4 is a view in end elevation of the forward end of the nozzle body, such view being taken in the direction from left to right in 'FIGS. 1 and 2 on line 4-4 of FIG. 2.

In prior fuel injection valve devices, the nozzle body,

/ or an element which in eifect forms an extension of the opened by high pressure fuel delivered to the nozz e; A

high pressure fuel passage extends within the main body of the device and into the body of the nozzle to the valve seats therein; a low pressure leakage fuel return passage extends rearwardly through the main body of the device.

The device of the invention includes improved means for effecting a seal betweenthe'parts of the high pressure fuel passage in the main body of the device and the nozzle body. v

This invention relates to a va ved nozzle for the spray% c portions being sealed to each other. I g v The invention, has among its objects .theprovision of animproved fuel injection valve device having the parts thereof so constructed andarranged that the required seal beween the confronting-ends of the portions ofthe pa'se sages in the main bodyjand the nozzle body of the. device a es I mO tflicient use of the areas-in the device available for sealing. j A furthervobject of the inv'entiomresidesrin the proand within the nozzle body, such nozzle body, is secured to the rear end of a main body or nozzle holder in alignment therewith. A reciprocable valve element or needle is mounted within a central longitudinal bore in the nozzle body, the forward portion of the needle projects forwardly from the nozz e body into an axial bore in the main body of the device, the forward end surface of the needle engaging an axially disposed pressure rod or spindle which is urged rearwardly by a coil compression spring;

High pressure fuel is fed through a longitudinally dis posed passage in the main body of the device, such passage extending to the rear end of the main body. In the annular forward transverse end surface of the nozzle body and coaxial thereof there is provided an arcuate groove which communicates with the rear end of the passage in the main body, two generally longitudinally extending passages in the extension of the nozzle body extending from said arcuate groove to diametrically opposed sides of an annular enlarged zone of the central bore in the nozzle body. Fuel is fed from such zone of the bore to the spray orifices of the device when the valve thereof is opened. 4

The required seal between the rear end of the main body and the forward end of the nozzle body or the extension thereof is formed by a surface to surface engagement of such bodies. It willbe seen that thereare thus required two complete zones of high pressure sealing between the two bodies, one on each side of the forward end of the generallylongitudinally extending passages in the nozzle body. As will be seen below, the present invention reducesthe length of the boundary surrOundingthe vision of the required seal in the above device in-a mini-- mum of 'space, whereby :the: sealing-surface area isincreased ascompared to thatjof prior devices of the. same diameter, or, ;whenthe diameter of the device} is reduced, the sealing surfaceareamay be madethe; same as that of larger diametered prior devices.

It'is also an object Of,'tl1e, pre'sent invention to provide, in adevice having? high pressure seal infacco'rdance with the invention, conduit "means, incorporating a-further sealing means related to the first: recited sealing to obtain the desired security of sealing between the parts.

means, for the exhaust of'leakage fuel from the device.

The above and further objects andinov'elfeatures of the invention will more fully appear from the-following description when-the samegjis read in connection. with. the accompanying drawings.'lt is to be expressly understood,

however, that the drawings are for the purposeofillus- FIG. 1 is a view in longitudinal axial section through high pressure conduitmeans at'the seal, and localizes the high, pressure conduitjm'eans to one-side of the device at the seal, thereby to eliminate one sealarea which was formerly necessary and to make itpossiblemore readily Atthe same time, the device also readily providesfor the secure, sealing of the path of discharge'oflow pressure leakage fuel from the device.

Turning now to the drawings, the illustrative fuel ini jection valve device shown in FIGS. 1- and 2 includes an elongated main r nozzle holder body 1(I and a spray nozzle body llhaving'a smaller diameter rear end 18 and alargerdiametered forward end 42.j'Parts 10'and 11 are held in coaxial-aligned relationship by an assembly sleeve or nut 12 having shoulder "to shoulder engagement at 13 with the' body 11 andthreaded engagement at 37 with the smaller diame'tered rear end portion 23 '0'f,the'body'-10-. The rear end of the device, shown-at the fight in FIGS. 1 and 2,: is adapted to extend throughan opening in the wall of acylinderiof an-internal'combustion engine, being retained therein by conventional'means not shown; The device'is sealed to the wall of the combustion chamber of theengine by a gasket 14 disposed about the-nozzle-body 1.1 and engaging therear end offth'enutlz; I v;

Liquid fuel under high pressure is fed into a port 15 in the forward end of the body through a conduit (not shown) attached to such main body. Such fuel travels through conduit means, to be described, in bodies 10 and 11, being discharged through a plurality of orifices 16 in the nose portion 17 at the rear end of the nozzle body. Leakage fuel, that is, fuel in the device which leaks past the needle flows into the rear end of the eccentric bore 32 in the main body 10 of the device and thence through a discharge passage 62 is discharged to a suitable tank or sump through a branch conduit 19 which is held upon the body 10 by an annular fitting 20 as shown in FIG. 1.

The novel structure of the device is more particularly shown in FIGS. 2, 3, and 4. As shown in FIG. 2, the nozzle body 11 has an axial bore 21 therein, there being an enlarged annular zone 22 in the bore intermediate the length thereof. Bore 21 extends from the forward transverse end surface 24 of the body 11 to a rearwardly converging frusto-conical valve seat 25, rearwardly of which there extends a small axial bore or sac hole in nose portion 17 in communication with the orifices 16. A reciprocable elongated noule needle or valve element 26 is disposed within the bore 21; the rearward portion 29 of the needle has a diameter somewhat less than that of bore 21, whereas the forward end portion 30' of the needle is of larger diameter and fits fairly accurately within the bore 21. The two

portions

29 and 30 of the needle are joined by a shoulder 28 which lies forwardly of the enlarged zone 22 of the bore. As its rear end the needle has a conical end 27 forming a second valve seat cooperating with the seat 25. The forward end portion 30 of needle 26 functions as a piston to retract the needle to its valve-open position when the space within the enlargement 22 of the bore 21 is subjected to high pressure fuel. The rear end surface 31 of portion 30 of the needle is constantly urged toward the valve closed position by a needle stop means 50, to be described, disposed within the rear end of the main body 10.

Within the rear end of the main body 10 there is disposed a second, rearwardly open and forwardly blind bore 32 which is parallel to the bore 21 in the nozzle body but has its axis offset from the axis of bore 21 through a distance E. There is thereby formed a sidewall in the rear end of the body 10 around the bore 32 which is of varying thickness, the sidewall and the rear end surface 35 of portion 23 of 'body 10 being thickest at a zone 34 and thinnest at a zone 36, as shown in FIG. 3. A single high pressure fuel supply passage 39 extends angularly from the central port at the outer end of the main body 10 generally longitudinally of the body 10 to terminate within such body at a location 40 which is disposed radially outwardly of and somewhat forwardly of the eccentric bore 32. Two small bores 41 extend from the end 40 of the passage 39 longitudinally of the smaller diametered, rear end portion 23 of body 10, the passages 41 lying parallel, spaced midway of the radial thickness of zone 34 of the portion 23 of body 10 and at equal distances from a radial axial plane therethrough, as shown in FIG. 3. p v I The forward larger portion 42 of the nozzle body 11 has a diameterequal to the diameter of the rear end portion 23 of body v10. When bodies 10 and 11 are assembled in operative position, as shown in FIG. 2, the transverse end surface 24 of body 11 engages the tranverse end surface 35 of the body 10. Disposed in the transverse end surface 24 of the body 11 is an arcuate groove 44 of such size as to enclose and communicate with the rear ends of the passages 41 in body 10. Extending angularly rearwardly from the ends of groove 44 are two parallel passages 45 in portion 42 of body 11, the passages 45 extending. to

drawn together by the nut 12, outer and

inner seals

46 and 47 are formed between such end surfaces, such seals surrounding the rear ends of the passages 41 in body 10 and the arcuate groove 44 in body 11. Because of the above described eccentric location of the bore 32 with respect to the bore 21,

such sealing zones

46 and 47 may be made with widths which are at least equal to those in the described prior art devices even though the device of the invention is made with a diameter which is substantially less than that of such prior devices. The sealing surfaces of

zones

46 and 47 are readily formed and finished by lapping to Withstand without leaking the relatively high pressure of the fuel supplied to the device.

Not only are

high pressure seals

46 and 47 formed between the bodies 10 and 11 as above described, but a further, low pressure seal is formed completely about the confronting end surfaces of such bodies which define the communicating ends of the

bores

21 and 32. The portion of such low pressure seal at the radially thinner zone 36 of the sidewall of the bore 32 is designated 49 in FIG. 2. As will be apparent hereinafter, leakage fluid which seeps between the forward portion 30 of the nozzle needle and the wall of bore 21 flows into the bore 32 and then outwardly therefrom through a passage 62 which communicates with the above mentioned discharge pipe 19.

Disposed within the bore 32 is a needle stop means generally designated 50. Such stop means has an elongated stem 51, disposed axially of the bore 32, and a disc-like head 52 secured to the rear end of the stem coaxially thereof. The peripheral, circular cylindrical surface of head 52 is finely finished, and is of such diameter as accurately to fit the bore 32 so as to serve as a pilot or guide for the needle stop. The head 52, which is disposed eccentric of the needle 26, is constantly thrust rearwardly into engagement with the forward end surface 31 of the needle by a coil compression spring 53 which is telescoped about the stem 51 of the stop means coaxially thereof and acts between a stop plate or disc 54 in the forward, blind end of the bore 32 and the forward end of a stack 56 of washer-like shims which are telescoped over the stem 51 and abut the head 52 of the stop means. As shown, the spring is of an outer diameter which is close to but slightly less than the diameter of bore 32. When the nozzle needle is in its rear, closed position, the forward end 55 of the stem 51 is spaced from the stop plate 54 by a predetermined distance or lift L, as shown in FIG. 2. The stop plate 54 has a diameter which is somewhat less than the diameter of bore 32. The forward, blind end of the bore 32 is provided with an annular groove 61 into which leakage fuel seeps past the edges of the stop plate 54. The rear end of the above described leakage fuel discharge passage 62 communicates with the groove 61, as shown in FIG. 2.

As shown in the drawings, and as above described, the needle stop 50 and the spring 53 are disposed with their longitudinal axes parallel to but eccentric of the longitudinal axis of the needle 26. It was heretofore considered that it was not possible to have the needle stop and its spring disposed eccentric to the needle, because it was thought that both the needle and the spring would rock or cock the needle stop out of alignment with the axis of the bore 32. It has been found, however, that the device shown and described performs entirely satisfactorily when constructed as follows. The projection of the longitudinal axis of the needle stop 50, that is, of the stem 51, head 52, and spring 53, should lie within the cross sectional area of the forward end of needle 26. The projection of the forward end of needle 26 should lie within the projected area of the head 52 of the needle stop, that is, the rear surface of head 52 should engage the entire end surface of needle 26. When the device of the and piercing the wall of the bore 21 at opposite sides of the annular enlargement 22- therein. The transverse end surfaces 35 and 24 of the bodies 10 and 11,- respectively, are accurately finished so that when the bodies are forcibly invention is constructed within the above design limits the needle stop reciprocates freely in bore 32 and does not tend to rock out of the axis of bore 32 nor does the head 52 tend to bind in such bore.

In order to insure the assembly of the bodies and 11 in the proper angular relationship, index marks 59 and 60, respectively, are provided upon them as shown in FIG. 2. Such index marks areso positioned that when they are aligned" the rear ends of passages 41' are accurately aligned with the arcuate groove 44 in body 11, thereby insuring the correct registration of

the'portions

41, 44, and 45 of the fuel supplying passage in the bodies 10 and 11. The index mark 60'is also desirably fixedly related to the various spray orifices 16, which in the embodiment shown are equally angularly spaced about the axis of the body 11. Other index marks may be' substituted for

marks

59 and 60, if desired. Thus opposed parallel fiat surfaces accurately angularly oriented about the body may be provided on the outer surface of body 10 in place of index mark 59, as for example at the forward end of such body.

Although only one embodiment of the invention has been illustrated in the accompanying drawings and described in the foregoing specification, it is to be especially understood that various changes, such as in the relative dimensions of the parts, materials used, and the like, as well as the suggested manner of use of the apparatus of the invention, may be made therein without departing from the spirit and scope of the invention, as will now be apparent to those skilled in the art.

I claim:

1. In a fuel injection valve device having an elongated main body, a nozzle body, means to secure the two bodies together in aligned relationship, a first, longitudinally directed central bore having a first valve seat in the nozzle body, a reciprocable valve element within the bore in the nozzle body, said valve element having a second valve seat cooperating with the first valve seat, resilient means for constantly urging the valve element rearwardly toward its closed position, and means for retracting the valve element to open the valve by high pressure fuel delivered to the bore in the nozzle body, the improvement which comprises a rearwardly open, second bore in the rear end of the main body, said second bore being disposed parallel to, markedly-eccentric to, and overlapping the first bore, the sidewall of the main body radially outwardly of the second bore being markedly thicker at a first zone than at a second, diametrically opposite zone, a plunger in the second bore, resilient means for constantly urging the plunger rearwardly into engagement with the valve element to thrust the valve element rearwardly toward its valve closed position, a first high pres sure fuel conducting passage in the main body, the rear end portion of such first passage extending longitudinally, and generally centrally in a peripheral direction, through the first, radially thicker zone of the sidewall of the main body radially outwardly of the second bore, said first passage extending to the rear end of the main body, and at least one second passage, disposed in the nozzle body, which extends from the forward end surface of the nozzle body to the bore in the nozzle body, the rear and forward ends of the first and second passages, respectively, communicating and being sealed together to form a conduit for forwarding fuel from the first passage to the first bore.

2. A device according to claim 1, wherein the main body has a transverse rear end surface, the nozzle body has a transverse forward end surface, said two end surfaces being in engagement, the rear and forward ends of the first and second passages, respectively, being sealed together by engaging zones of the said transverse end surfaces of the bodies which surround the confronting ends of the first and second passages.

3. A device according to claim 2, wherein the rear end portion of the main body containing the second bore is circular cylindrical, and the forward end portion of the nozzle body containing the forward end of the first bore is circular cylindrical.

4. A device according to claim 3, wherein the rear 'end portion of the main body and the forward end portion of the nozzle body are of the same diameter and are disposed coaxially.

5. A device according to claim 2, wherein said first passage has a first, larger diametered forward portion, the rear end of which lies adjacent the forward end of the second, eccentric bore, and a plurality of generally parallel second, smaller diametered branch portions extending from the rear end of the first portion alongside the second bore to the rear end surface of the main body.

6. A device according to claim 5, comprising a plurality of generally parallel second passages in the nozzle body having their forward ends sealed to the rear ends of the second branch portions of the first passage.

, 7. A device according to claim 6, wherein the first bore is of substantially less diameter than the second bore and comprising an arcuate groove in the forward end of the nozzle body connecting and substantially encompassing the forward ends of the second passages.

8. A device according to claim 1, wherein the second, eccentric bore is blind in a forward direction, the plunger has a stem and an enlarged head at the rear end of the stem, the head being engaged eccentrically of its axis by the forward end of the valve element, and the means resiliently thrusting the plunger rearwardly comprises a coil compression spring telescoped about the stem of the plunger and held in compression between the forward end of the second bore and the head of the plunger.

9. A device according to claim 8, wherein the head of the plunger is disposed coaxially of the plunger and accurately and guidingly engages the wall of the second bore, and the springhas an outer diameter which is close to but slightly less than the diameter of the second bore.

10. A device according to claim 2, wherein the rear end of the second bore is sealed to the forward end of the first bore by engaging zones of the said transverse end surfaces of the bodies which surround the confronting ends of the first and second bores, and comprising a third, low pressure leakage fuel exhaust passage leading from the second, eccentric bore.

11. A device according to claim 10, wherein the second, eccentric bore is blind in a forward direction, and comprising a stop plate within and loosely fitting the forward end of the second bore and adapted to be engaged by the forward end of the plunger, and a groove in the forward wall of the second bore beneath the stop plate, and wherein the fuel exhaust passage extends from said groove generally longitudinally of the main body.

12. A device according to claim 1, wherein the projection of the longitudinal axis of the plunger lies within the cross sectional area of the forward end of the valve element.

13. A device according to claim 1, wherein the projection of the forward end of the valve element lies within the projected area of the end of the plunger which it engages.

14. A fuel injection device having an elongated main body with a transverse rear end surface, a nozzle body having a transverse forward end surface, means to secure the two bodies together in coaxial aligned relationship and to thrust them together with their respective transverse end surfaces in sealing engagement, a first, longitudinally directed central bore in the nozzle body, a reciprocable valve element within the bore in the nozzle body, means for moving the valve element forwardly to open the valve by high pressure fuel delivered to the bore in the nozzle body, a rearwardly open, second bore in the rear end of the main body, said second bore being disposed parallel to, markedly eccentric to, and overlapping the first bore, the sidewall of the main body radially outwardly of the second bore being markedly thicker at a first zone than at a second, diametrically opposite zone, means in the second bore engaging and constantly urging the valve element rearwardly toward its valve closed position, a first high pressure fuel receiving pasage in the main body, said first passage extending in the main body to emerge at a zone of the transverse rear end surface of the main body which lies generally centrally of the thicker portion of the sidewall of the second bore in directions both peripherally and radially thereof, and at least one second passage, disposed in the nozzle body, which extends from the forward transverse end surface of the nozzle body to the first bore, the rear and forward ends of the first and second passages, respectively, communicating and being sealed together by said engaging surfaces of the main body and the nozzle body to forward fuel from the first passage to the first bore.

. References Cited UNlTED STATES PATENTS M. HENSON WOOD, R, Primary Examiner I. I. LOVE, Assistant Examiner