US2372169A - Fuel-injection apparatus for internal-combustion engines and like purposes - Google Patents

Description

G. AMI-:RY INJECTION APPARATUS FOR INTERNAL March 27, 1945.

' FUEL 2,372,169 coMBUsTIoN ENGINES AND LIKE Punross Filed Apr-i1 19, 194s mm-Inl..

35 Gsokcf Ane-kr Kt N Patented Mar. 27, 1945' l'UNITED STATES 2MT1-:rrr OFFICE FUEL-.INJECTION APPARATUS FOR INTER- ENGINES 'AND LIKE NAL-CODIBUSTION rUarosEs George Amery, Harborne, Birmingham 17, England, assignor to Amery Holdings Limited, Oldbury,A Birmingham, England, a British 4com- Pall! Application April 19, 1943, Serial No. 483,652 In Great Britain February'l'l, 1942 s claims. (c1. 137-144) This inventicn'comprises improvements in or relating to fuel-injection apparatus for internalcombustion engines.

According to'the present invention a fuelcontroll valve comprises a valve-body, an inlet thereto, a plunger therein having aduct extending through it from one end open to the inlet toward a seating at the other end, an obturatingmember movable toward the plunger to bear on the` seating and thereby close the duct against the flow of fuel through the duct, a piston face on the obturating-member exposed to inlet fuelpressure to urge it open and control means independent of the fuel-pressure, controlled by the valve, to close the obturating-member againstv said pressure, whereby seating andunseatingof the obturating-member is efiectedto close andv open the valve, the plunger and seating thereon being freel to move with the obturating-member for a short distance in the closing direction after the valve is closed. v

The invention includes an iniector or distributor having a fuel-control valve as above set.'

forth wherein an expansion chamber is provided between the` plunge'rand an annular shoulder or abutment engaging therewith, whichchamber is in communication with the fuel-nozzle of the iniector and on the relative movementy which'l occurs between the shoulder and plunger when.

the plunger and obturating-member move together after the valve is closed serves to relieve fuel-pressure at'the nozzle for the purpose of ensuring a rapid cessation of Iinjection when the Y valve is closed. v

' The fuel-control valve may employed to -oontrol the admission of fuel to a needlevalve seating for the injector or distributor and the l closing `means for the needle-valve or plunger or obturating means, as the case may be, may be assisted, if desired, by spring action, although in certain forms according to the invention the employment of springsmay be obviated.

'Ihe preferred arrangement according tothis inventionleads to an exceptionally rapid fall of fuel-pressure when obturation occurs butnot before.

v Referring now to the accompanying drawing--V Figure 1 illustrates in longitudinal section a fuel-injection devic'e for an internal-combustion engine, while rFigure 2 illustratesa lcross-section through the line II-II in Figure 1.

Figure 3 illustrates in cross-section a modification. j

Figure 4 is a diagram of the essential parts of the valve as illustratedin Figure 3. The invention willnow be described, by way of example, as applied, more particularly to the arrangement described and illustrated with reference to Figures '4 and 5 of my United States Patent No. 2,053,311, granted September 8, 1936, wherein a number of injectors are operated from l a single fuel supply system. A pipe connection with this system is made directly to each injector for injection purposes and a branch from this pipe' connection is led by way of a mechanically-actuated valve 'to each injector. This mechanically-actuated valve controls the. operation of the injector associated therewith so that at the moment when injection is to commence the valve cuts oil? the piston closingmeans from communication with the supply system and places the chamber containing they pistonc1osing-means in yconnection .with the atmosphere or with a drain pipe, while at the moment when injection is .to be cut on the valve places the piston closing-means in the injector in communication with the 'supply system.

The inlet pipe I I, -Figure l,.leads fuel from the fuel pressure system to the injectorlIZ.' The Y, b ody I 3 of the injector is tubular and its upper bore 22 in which a free plunger 23 is slidable, the' upperend of the bore 22 opening into thev recess I9. The plunger 23 is provided with a central duct 2l and the lower end of this plunger `is integral withV a piston 25 arranged in a cham-V ber 26. The lower end of the chamber 26 is formed by the upper end Awall of a constriction 28 arranged between this chamber and a charnber 29,`the lower wall of the chamber 26 being f'med with an annular lprojection 30 concentric with this chamber. The constriction 28 has a central bore 3I in which a plunger 32 is slid-A able, the upper 4end face of this plunger being adapted to seal or act as an obturating-member for the lower end of the duct 21 of the piston 25 when these parts are in contact with each other.

A duct 33 extends between the lower end of ius. /v

.if desired.

' passes.

' nipple 65 of the body I3 of the injector.

the chamber 26 and the upper end of the chamber 29, the upper end of this duct opening from the face of the annular projection 30 into the former chamber.

A bore 34 extends from the chamber 29 to the lower end of the injector body I3. The bore 34 is divided into two control-chambers 35 and 36 by the member 31 which is fixed in position by means of' a grub screw 33. A duct 39 of the member 31 interconnects the control-chambers 35 and 36, and this duct is connected by a duct 40 with a control-pipe 4I from the mechanicallyactuated valve above described which acts as a distributor. The control-pipe 4I is formed with a conical end 42 which fits into the correspondingly shaped part of the duct 40. The end 42 of the pipe 4I is pressed into uid-tight'contact with the conical wall of the duct 40 by the annular projection 43 on the end of a nut 44, the screw of which engages with 45 of the nipple 46 formed on the body I3 of the injector, when the nut 44 is tightened up.

In the control-chamber 35 is disposed a control-piston 41 which actuates the plunger 32. It will be noted that the area of control-piston 41 is somewhat greater than that of plunger 23 to ensure that it can lift the plunger against fuelpressure in pipe II. mounted a piston 48 which is connected to, or formed integrally with, the stem 49 of a needle valve vwhich seats in a, nozzle 52. The needle valve 49 need not, in the construction according to the present invention, be spring-closed, but a spring may be provided to assist in closing it,

'Ihe lower end 5I) ofthe injector body I3 is screw-threaded externally and with this end an internally screw-threaded union I engages. This union connects the nozzle 52 with the injector body I3.

VBetween the nozzle 52 and the lower end of the injector body I3 is arranged a jointing ring 53 formed with a central clearance hole 54 through which the stem 49 of the needle valve The jointing ring 53 has a duct 55 formed in it which is connected at its lower end to a duct, not shown, leading to a chamber in the nozzle the internal screwthreadV In the chamber 36 is.

In Figure 1 the position of the parts corresponds to that in which the needle valve is closed and consequently no fuel is being injected into the cylinder of the internal-combustion engine with which the injector is associated. The mechanically-operated valve or distributor has opened the distributor control-pipe 4I to the pressure of the fuel supply system so that the pressure of the fuel oil in the ducts 4D and 39 and in the adjacent ends of the control-chambers 35 and 36 is that of the supply pressure in the fuel system. Accordingly the piston `I8 holds the surrounding a. shoulder on the needle valve, while y opens into a cylindrical chamber 51 closed at itsouter end by a screwed plug 58. Another duct 5.9 connects the chamber 51 with the lower part of the chamber 26.

A duct 60 is formed in the body I3 of the injector I2 and thisduct connects the lower end of the chamber 36V (below the piston 48) with the chamber 29. The chamber 29, Figure 2, is connected by a'duct 6I to a pipe 62 leading to the atmosphere or acting as a drain pipe and connected to a. suitable'receptacle. The pipe 62 has a conical end 63 which is forced into fluid-tight contact with a similarly formed end of the duct 6I on screwing up the nut 64 of which the screwthread engages with an internal thread on4 the The plungers 23, 32 and the pistons 25,

tight manner in their correspondingly shaped respective bores or chambers, 25. 3|, 35 and 36 and packing grooves may be formed on the plungers or pistons if desired.

The operation of the injector above described is as follows:

needle lvalve closed and the piston 41 holds the plunger 32 against the lower end of the duct 21 in the piston 25 and has sealed this duct. -The pressure of the fuel oil in the inlet pipe I I which acts on the upper end of the plunger 23 forms a fluid-tight joint between the lower end of this plunger and the upper face of the piston 25. Thelower face of the' piston 25 is held clear of the annular projection 30 so that pressure in the nozzle chamber is relieved through the ducts and 56, chamber 51, duct 59, the part of the chamber 25 between the lower face of the piston 25 and the upper face of the constriction 28, duct 33, chamber 29, duct 6I and pipe 62. The pipe 62 leads to the atmosphere or to a drain pipe. The parts remain in the above position until the instant arrives for fuel injection to commence.

When this instant arrives the pressure of the fuel oil system is cut off from the control-pipe 4I and consequently the pressure of the oil in the control-pipe 4I, duct l4I), duct 39 and the adjacent ends of the control-chambers 35, 36 is relieved with the result that the pressure of the fuel supply system in pipe Il acting on the plunger 23 forces the plunger downwards and also the piston 25, plunger 32, and piston 41, until the lower face of the piston 25 rests on and makes a fluid-tight joint with the annular projection 30 which prevents any further movement of the piston 25 andA also of the annular piston 23. 'I'he pressure of the fuel oil acting in the duct 24 on the upper end of the plunger 32 forces the-plunger downwards still farther with the result that the fuel oil may now pass from the duct 21 into the space enclosed within the annular projection 30 and from thence through the duct 59, chamber 51, ducts 56 and 55 to the nozzle chamber and the pressure of the fuel oil on the needle valve shoulder opens the valve so that fuel oil is injected in a finely atomised condition into the combustion chamber of the cylinder of the internal-combustion engine associ- I 41 andY 48 are all of cylindrical form and slide in a fluidated with the injector. The piston 25 when in contact with the annular projection 30 seals the duct 33 leading to the chamber 29 and to the pipe 52 which leads to the atmosphere or to a drain pipe.

When the instant arrives for injection to terminate, the distributor places the control-pipe 4I, duct 40, duct 39 and controlchambers 35 and 36 in communication with the pressure fuel supply system so that the pressure in this system acts on the adjacent ends of the pistons 41 and 4B. The pressure on the piston 48 closes the needle valve on its seat while the pressure of the fuel supply system is= still vacting thereon, and as the area'of the control-piston 41 is greater than the area of the plunger 23 plus that of the duct 24, the plunger 32 closes the lower end of the duct 21 and then forces the piston 25 upwards so that thelower Aface of the piston 25 is moved away from the annular projection 30 upon which it previously rested. When the piston 25 has been raised of the annular projection 36 the pressure in the nozzle chamber is relieved by .y beingiconnected to the atmosphere or drain pipe `by way ofthe duct 55, ductf56, chamber 51, the

part of the chamber 26 beneath the lower face of the piston 25,duct 33, chamber 29,v duct 6I and pipe 62.

The above cycle of operations -is repeated so long as the injection system ,.functions.

Instead Lof forming the various `bores and chamber in the body f theinjector, they may be formed in one or a number of liners and assembled with the body. v.

The injector as above described while operating eiliciently Vis open to the disadvantage that in the event of a particle of carbon lodging on the needle valve seat during combustion' or compression strokes of the engine cylinder associated with the injector, and of the needle valve being.

thereby prevented from closing prolllerly,- gases under pressure could blow fuel oil remaining in the injector ducts and passages into the atmosphere or into the drain pipe. In order to obviate the above contingency arising, the construction of the injector may be modified as illustrated diagrammatically in Figure 3.

In Figure 3 a plunger 23 has a central duct 2t and is slidably mounted fluid-tight in a bore 22 of the injector body I3. Beneath. the bore 22 is arranged a guide member 1U which is xed in an enlarged vbore. 1I. At its upper end the guide member has a chamber 1.2 which is of smaller diameter than the bore 22 so that a shoulder 13 is formed upon which the plunger 23 rests when in its lowest position. The plunger 32 is slidably mounted fluid-tight in a bore 14 of the guide member 10, the obturating plunger 32 being operated by a control-piston 41 slidable in a chamber 35, The control-chamber 35 vis formed in a liner inseited in a bore 16 ofthe body I3 of the injector and is interconnected by a duct 39 with a chamber 36 also formed in the liner 15. In the chamber 36 there is slidably mounted a piston 48 which is formed on the stem 49 of the needle valve of the injector. The duct 39 is connected by' a duct 40 to a nipple 46 onthe body I3 of the injector, the nipple being connected to the distributor pipe. Duets 11 and 18 leadfrom the upper-end of the chamber and from the lower end of the chamber 36 to the atmosphere or to a drain pipe. The chamber 12 is connected by a duct 19 to the. needle valve chamber in the nozzle. A screwed plug B0 serves as an adjustable stop to limit the outward or return movement of the plunger 23. The remaining parts of the injector are similar to that described with reference to Figures 1 and 2.

By arranging the injector as just described a sulicient increaseof volumetric capacity may be given (bythe increase of volume of expansion chamber 12 when the plunger 32 is lifted) to the ducts associated with the nczzle valve chamber and located within the injector so as to relieve the pressure in the fuel oil ducts without discharging'the fuel tothel atmosphere or to the drain pipe.

When injection commences the dfstributor cuts off the pressure fuel oil system from the distributor pipe connected to the injector by the nipple 48 and relieves the pressure in the ducts 43 and 39 and in the ends of the control-chambers 35 and 36 connected by the duct-39. The pressure of the fuel oil supply acting on the plunger 23 forces this plunger together With the obturating plunger 32 and the piston 41 downwards until ated.

the plunger 22 rests on the shoulder 13. -l The pressure of the fuel oil acting in the 'duct 24 on the upper end of the plunger 32 forces this plunger still farther downwards and at the same time breaks the seal between the upper end of this plunger and the lower end of the plunger 22. 'The fuel oil may then freely pass by way of the chamber 12 and the duct 19 to the needle valve which it opens and so enters the cylinder of the engine associated therewith.

When injection terminates the distributor connects the adjacent ends of the control-chambers `35 and 36 through the ducts 39 and 46 and the nipple 4| to the pressure fuel supply system. The piston 48 is operated and closes the needle valve. Moreover, the control-piston 41 rises and operates the plunger 32 so that it seals the lower end of the duct 2li oi the plunger 23 and raises the plunger sufficiently to supplement the capacity of the chamber 12 by that of the displacement of the plunger 23 in the bore 22 and to relieve the pressure in this chamber and also in the duct 19 andthe nozzle valve chamber.

When injection recommences,' the plunger 32 is pressed down by the pressure of the fuel oil supply acting on the plunger 23, and the pressure in the chamber 12 and duct 19 and nozzle chamber is increased prior to the opening of the duct 24. This tends to reduce or prevent pressure waves and fluctuations of pressure in the whole system. With this construction the needle valve will be efficiently sealed by plunger 19 even if it does not seat properly at the nozzle 52 and `the fuel oil around the needle valve seat when. the valve has been closed is not under pressure owing to,the relief aiorded by expansion of chamber 12.

It is desirable when applying the presentinvention in practice toinclude a valve so a1'- ranged that injection cannot talee place until a suitable pressure of injection is generated.

The valve which is constituted by the plunger 23 coacting with the plunger or obturatingmember 32 forms in itself a very useful valve i which may be used in other connections, for example a-s a valve for the distributor itself, such for example as the distributor valve shown at 9|' in Figure 5 of my United States Patents 2,291,- 939, granted August 4, 1942, and 2,281,302, granted April 28, 1942. In Vthis case the plunger 32 of such a distributor valve may be cam-oper- The essential parts of the valve, when iluid-pressure-operated, are illustrated separately in diagrammatic form in Figure 4 and bear the same reference numbers as in Figure 3. In this case A represents an inlet, B an outlet to be controlled by the valve and C an inlet for pressure to control the opening and closing of the valve. l

The constructions of injectors hereinbefore described are not limited to such as have pistonclosing means for the fuel admission-valve which hold the needle valve 49closed substantially solely by fiuid pressure as movement of either or both of the. piston-opening and piston-closing means may be assisted by spring action.

' I claim: x

1. A fuel-control valve for fuel-injection apparatus of internal-combustion engines and like purposes comprising a valve-body, an inlet thereto, a plunger therein having a duct extending through it from one end open to the inlet toward a seating thereon at the other end. an'obturating-member movable toward the plunger to bear Von the seating and thereby close the duct against cated and an inlet from an independent supply of fluid under pressure to said chamber to close the obturating-membler against said pressure,

whereby seating and unseating of the obturat` ing-member is eiected to close and open the valve, the plunger and seating thereon being free to move with the obturating-member for a short distance in the closing direction after the valve is closed.

2. A fuel-control valve for fuel-injection apparatus of internal-combustion` engines and like purposes comprising a valve-body, a plunger therein having a duct extending through it from a seating thereon at oneend, an obturating-meinber movable toward the seating to obturate the duct, means to admit uid pressure to the end of the plunger and urge the plunger and obturatingmember in one direction, an abutment in the path of the plunger to interrupt its movement while allowing the movement of the obturating-niember to continue under the said pressure and thus to open the valve, an outlet passage leading from the obturating member beyond the seating on the plunger, a second piston-face on the other.

end of the obturating member, a control-chamber in which said second piston-face is located and an inlet from an independent supply or iiuid under pressure to said chamber to return the obturating-member to close the valve and to thereafterv continue the movement of the obturating member and plunger together for a short distance so as to return the parts to their initial position.

3. A valve as claimed in claim i, wherein an expansion chamber is provided between the plunger and an annular shoulder'or abutment engaging therewith, which chamber is in com munication with the outlet passage and, on the relative movement which occurs between the shoulder and plunger when the plunger and obturating-member move together after the valve is closed, serves to relieve pressure in the outlet passage.

fi. A valve as claimed in claim i wherein the movement of the plunger with the obtiiratingn asume member after the valve is closed is limited by an adjustable stop for the purpose described.

5. A valve comprising in combination a valve l body having a cylindrical bore near one end thereof, an inlet at the end of the valve body to the cylindrical bore, a plunger slidable in the bore and pierced with a longitudinal passageway, a seating on the end of the plunger remote from the inlet, the plunger being at liberty to execute limited endwise sliding movement in the bore, a smaller bore in the valve body beyond the plunger and coaxial therewith, an obturating member slidable in said bore and capable of sealing the passageway through the plunger by abutting upon the seating, a chamber surrounding the junction of the obturating member and the plunger, an outlet passage from the said chamber, an additional valve member movable to open and close the outlet passage and control means for closing the second valve and for simultaneously closing the obturating member upon the seating and forcing back the plunger to relieve pressure in the outlet passage between the chamber and the additional valve member.

6. A valve comprising in combination a valve body having a cylindrical bore near one end thereof, an inlet at the end of the valve body to the cylindrical bore, a plunger slidable in the bore and pierced with a longitudinal passageway, a seating on the end of the plunger remote trom the inlet, the plunger being at liberty to execute limited endwise sliding movement in the bore, a smaller bore in the valve body beyond the plunger and coaxial therewith, an obturating member slidable in said bore and capable of sealing the passageway through the plunger by abutting upon the seating, a chamber surrounding the vjunction of the obturating member and tne plunger, an outlet passage from the said chamber, an additional valve member movable to open and close the outlet passage, a control chamber in the valve body, a control piston upon the obturating member open to said control chamber, a second control piston upon the said additional valve member, also open to said control chamber and an inlet to the valve body for application ci fluid pressure to said control chamber to close the additional valve andto operate the obturating member to close it upon the seating of the plunger.

GEG'RGE

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