US2197944A - Combined fuel pump, injection and spray jet for use with an internal combustion engine - Google Patents

Description

April 23, 1940. R VEN 2.197.944

COMBINED FUEL PUMP, INJECTION AND SPRAY JET FOR USE WITH AN INTERNAL COMBUSTION ENGINE Fi1ed-June 20, 1939 2 Sheets-She e t 1 51 I 34 53 r- 35 Ti? 1 p I t g "In I :5? m T a 2 P 4 m 2 J0 22E 7 Q Q J6 26 W 1 .ZL Y A 17 i2 g H :5 .12 .14 flan? April 23, 19440- A. R. F. RAVEN 2.197.944 A INJECTIO COMBINED FUEL P N AND SPRAY JET FOR USE WITH A NTER COMBUSTION ENGIN Filed e 20, 1939 Sheets-Sheet 2 Patented Apr. 23, 1940 comma!) rum. rum, INJECTION AND sraar .m'r ron use wrrn an mrnamn oomnnsrron Enema Arthur Robert rennin Raven, Hong Kong, China Application June 20, 1939, Serial at. 280.147

In Great Britain September 13, 1937 -5 Claims.- (01. 128139 This invention relates to a self-contained combined fuel pump and injector, operating with a solid or airless injection compression ignition system, and applicable for use with an internal combustion engine designed normally for operating on petrol, so that the petrol engine can be converted into a solid injection compression ignition engine.

The invention is particularly applicable to operating with "solid injection on a two-stroke cycle and by way of example, a self-contained combined fuel pump and injector suitable for use on a petrol engine 'will be hereinafter described with reference to the accompanying drawings,

wherein:

Figure l is an axial section through one embodiment of the injector.

Figures 2 to 5 tranverse sections on lines 11-11; LII-III; IV-IV and V--V respectively of Figure 1; and,

Figures 6 and 7 are side and end views re"- spectively, showing the application of the embodiment of Figure 1 to the cylinder in horizontal disposition instead of vertical.

In accordance with the embodiment of the in vention shown, a hollow plug I is provided which has its lower end extremity screw-threaded at 2 to engage a screw-threaded opening in the cylinder head, such as the existing opening for the sparking plug. The lower end of the bore of the hollow plug I. is narrower than the upper end and forms, together with the bore of a gland nut 3 in the upper end of the plug bore, a cylindrical seating for a pump barrel 4 which has a comparatively large flange 5 with a screwthreaded periphery 6 near its upper end. The periphery of .the enlarged upper end of the plug is'also screw-threaded at I, the threads of the barrel flange and of the plug top being of different hand, i. e. one a right-hand thread and the other a left-hand thread, so that the rotation of a collar 8 screwed internally to engage the barrel flange and plug top threads 6 and I, effects movement of the barrel 4 axially in relation to the plug I. In this way the "timing of the valve is altered, that is, the pump barrel and with it the pump plunger contained therein may be adjusted in relation to the position of-the engine piston and thus effect earlier or later opening of the needle valve 9 for delivery of the fuel, to be hereinafter referred to. The collar 8 is partially rotated by the vehicle driver through the medium of any suitable remote control means connected to the said collar. Means are provided to prevent rotation of the barrel 4 relative to the plug I; in the embodiment there is employed for this purpose a series of pins l0 prodecting outwardly from the plug and slidable within holes in the barrel flange 5. In the lower end of the pump barrel-4 is slidably housed the pump plunger ll consisting of a hollow cylindrical ing both ends reduced in diameter, the bottom reduced portion being accommodated as a snug sliding lit in the constricted lower end of the pump barrel bore. The bottom end of the plunger normally projects down below the bottom of the barrel 4, which, in turn, normally projects down below the plug I. In the upper part of the pump barrel 4 and projecting up beyond the top thereof is a fuel regulating sleeve l2 whose lower end extends into the annular space existing between the upper reduced portion of the plunger H and the surrounding barrel 4. The remaining part of the annular space below the bottom extremity of the sleeve l2 constitutes a fuel chamber IS in which oil is admitted through'a ring of orifices l4 provided in the barrel wall from a concentric annular space 15 existing between the barrel 4 and the plug I, admission of fuel to the space It being through an inlet nipple IS. The oil from the fuel chamber 13 enters through the bore of the hollow pump plunger ll through-another series of orifices II. The ca-' pacity of the fuel chamber I3 is varied by relative longitudinal movement between the plunger II and the regulating sleeve l2. The regulating sleeve I2 is normally held in its lower position (in which it is seated on a shelf It in the barrel interior) by means of a coil spring 19 encircling said sleeve [2 and interposed between a flange 20 thereon and the roof of a cap 2i which is screw-threaded on to a hollow boss 22 provided on he barrel 4 above the flange 5 thereof. Means are provided to prevent relative rotation between the pump barrel 4. and the-regulating sleeve l2, such as a pln-and-slot connection l2a.

Extending centrally through the appliance is the needle valve 9 whose tapered point 23 normally rests on a conical seating 24'provided at the bottom of the bore of the pump plunger H, the tip of the needle closing a fine-diameter oil injecting jet or orifice 25 which. extends down from the plunger bore to a conical recess 26 on the bottom face of the plunger H. The lower end of the valve 9 is of lesser diameter than the bore of the plunger II, or other suitable provision is made so that the ducts H are in communication as indicated at 21, through said bore with the jet orifice 25 under the control of the valve 23, for the flow of fuel oil between the oriflces I! in the plunger wall and the jet or orifice 25 at the tip of the plunger. The needle valve 9 projects up from the plunger bore into the interior of the regulating sleeve [2 and is provided above the top of the plunger with a flange or collar 28 between which and an adjustable Y through-bore nut 29 screwed into the top of the on the top end of the regulating sleeve I2 are a pair of collars 32 and 33 having opposed ratchet faces 38, one of which (32) is loose and the other (33) anchored by the grip screw 35 to the regulating sleeve. The loose ratchet collar 32 is on the fuel is regulated by the adjustment of the regulating sleeve spring I9 and of the valve spring 38, the tension or pressure of these two springs being adjustable by manipulating respectively the cap 2| screwed on to the boss 22 of the barrel and the nut'29 screwed in the upper end of the regulating sleeve I2. The upward or pres-.

the top of its stroke and accordingly when its motion is slow and decelerating. The timing of the moment of contact is regulated by partial rotation of the collar 8 which mutually connects with the plug I and the barrel flange and the quantity of the fuel charge is regulated by partial rotation of the loose ratchet collar 32 which imparts axial movement to the fuel regulating sleeve I2. As the sleeve spring I9 is stiffer than the valve spring 30, the pressureexerted on the oil overcomes that exerted on the valve 9, so that the valve lifts to uncover the spray jet or orifice 25 in the plunger tip. The valve 9 is returned to its seating under the pressure of its spring 30 when theplungenll ceases to contact with the piston abutment 3 and the plunger is then returned by the spring 30 to the suction stroke and intake of a new oil charge. It will be observed that the piston abutment 31 is grooved radially to provide channels 38 along which the fuel can flow whilst the abutment is in contact with its seating 25 in-the end of the plunger II.

In the foregoing description a vertically disposed appliance attached to the crown of the dylinder head has been described and in'this case the abutment on the piston takes the form of an adjustable stud on the piston crown, as shown,

the channels serving to spread the oil spray. A V split lug 39 on the piston crown adjoining the piston wall would be employed, for example, when the appliance is horizontally disposed, as shown in Figures 6 and 7.

In the event of chokage of the jet of the plunger, relief is provided by a series of auxiliary orifices 40 (see Figure 1) normally covered by the regulating sleeve I2 but uncovered when the resistance of the sleeve spring I9. is overcome, the auxiliary orifices 4B feeding the oil from the pump chamber I3 back to the reservoir I5.

I claim:

1. A combined fuel pump and injector for internal combustion engines of the compression ignition type comprising a barrel, a pump plunger within said barrel and reciprocable relative thereto, means limiting inward movement of said plunger relative to said barrel, said pump plunger, when at its limit of inward movement in said barrel, being disposed to be engaged and to be moved outwardly in said barrel by an abutment on the engine piston during the final portion of the outward stroke of the piston, the inner end portion of said plunger having a liquid tight relationship to said barrel, the outer end portion of said plunger :being spaced from said barrel, a sleeve extending into the space between the outerend ,portion of said plunger and said barrel and' cooperating with said barrel and plunger to provide therebetween a liquid fuel chamber the outer end of which is defined by the inner end of said sleeve, means for the supply of fuel to said chamber when said plunger is at its limit ofinward movement in said barrel and for the cutting on of the fuel supply to said chamher when said plunger is moving outwardly in said barrel, said plunger having an axial bore and a transverse'duct providing constant communication between said bore and the inner endof said fuel chamber, said plunger also having a fuel outlet orifice and an outwardly facing valve seat disposed inwardly with respect to said duct and in constant communication through said bore with said duct, a valve cooperating with said valve seat to control fiow of fuel from said bore through said orifice, said valve having a stem disposed in said bore and liquid tightly fitting said bore outwardly with respect to said duct so that under the influence of a predetermined pressure of the liquid fuel when the valve is seated and the plunger is held against inward movement the valve is moved outwardly relative to the plunger and thereby is'unseated, spring means resisting outward movement of said valve, and other spring means resisting outward movement of said sleeve, said spring means being of strengths relative to each other such that the pressure of the liquid fuel developed by outward movement of the plunger in the barrel is effective to impart outward opening movement to the valve prior to outward movement of the sleeve.

2. A combined fuel pump and injector as set forth in claim 1 including means for adjusting the sleeve inwardly and outwardly relative to the barrel to vary the volume of the fuel chamber.

3. A combined fuel pump and injector as set forth in claim 1 including means for adjusting the barrel inwardly and outwardly to .vary the position of the plunger relative tothe engine cylinder when said plunger is at its limit of inward movement within the barrel, thus to vary the time at which the plunger is engaged and moved outwardly by the piston abutment.

4. A combined fuel pump and injector as set.

forth in claim 1 in which the plunger and the piston abutment are formed to cooperate when engaged with each other to provide therebetween a series of small passageways radiating

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