US2672817A - Fuel injection pump for internal-combustion engines - Google Patents

Description

March 23 1954 w. FRIEDLANDER 2,672,817

FUEL INJECTION PUMP FOR INTERNAL-COMBUSTION ENGINES Filed April 3, 1951 5 Sheets-Sheet l eg m I 77/ ELM ' 56 1F 52 50 42aZ2T 6 40 E a\ 4 25 mum I 24 J un 2017 /5 7 2,425 2a Q m f March 23, 1954 w, FRIEDLANDER 2,672,817 FUEL INJECTION PUMP FOR INTERNAL-COMBUSTION ENGINES 5 Sheets-Sheet 2 Filed April 5, 1951 'pww'iia A TTORNE Y$ Mal-ch23, 1954 w FRlEDLANDER 2,672,817

FUEL INJECTION PUMP FOR INTERNAL-COMBUSTION ENGINES Filed April 3, 1951 5 Sheets-Sheet 3 0 25 O Q O Q Z5 24 g 12 25a March 1954 w. FRIEDLANDER FUEL INJECTION PUMP FOR INTERNAL-COMBUSTION ENGINES Filed April 5, 1951 5 Sheets-Sheet 4 III/III m M 9 5 W v fi 5 J Ww v a w m 3 a 1, 6

7 2 5 G J i m March 23, 1954 w, FRIEDLANDER 2,672,817

FUEL INJECTION PUMP FOR INTERNAL-COMBUSTION ENGINES Filed April 5, 1951 5 Sheets-$heet 5 Patented Mar. 23, 1954 FUEL INJECTION FUD ll FOR INTERNAL- COMBUSTION ENGINES William Friedlander, Hinchley Wood, Esher, England, assignor to Mono-Cam Limited, London, England, a company of Great Britain Application April. 3, 1951, Serial No. 218,932

Claims priority, application Great Britain April 5, 1950 9 Claims.

This invention relates to fuel injection pumps for internal combustion engines and is concerned with pumps of the type (referred to herein as the type specified) comprising a housing within which rotates a common face cam adapted to cause reciprocation of pump plunger-s in respective cylinders having their axes parallel with, and disposed around and equidistant from, the axis of the cam.

An example of such a pump is described, for example, in the specification of Patent No. 2,517,483, in which example the length of the effective delivery part of the stroke is adjusted for all the plungers uniformly with the aid of a common member arranged to adjust the axial position of sleeves engaged over the respective plungers and co-operating with by-pass or spill passages formed in the plunger themselves. The common adjusting member referred to may be arranged to be operated substantially in ac cordance with a pressure variation which may be that occurring in the induction or exhaust system of the engine fed by the pump or that arisins, in the interior of the pump housing due to the spill of fuel from the pump cylinders. structions embodying these features are described in the specifications of oo-pending applications Ser. Nos. 158,359 and 168,508.

In combination with fuel injection pumps of the type specified, it is generally necessary to provide afuel lift or feed pump which will serve to bring fuel from a tank, which may be at a lower level than the fuel injection pump, to the inlet connection of the latter. It is the object of the present invention to provide an improved and compact construction of fuel injection pump of the type specified having an internally disposed fuel feed pump.

According to the invention, in a fuel injection pump of the type specified, a fuel feed pump is disposed within the housing substantially centrally of the ring of pump plungers and means is provided for operating the feed pump from the common face cam Which actuates these plungers.

With advantage, manually operable means is clude an element which is operable manually from the exterior of the housing, when desired.

The invention will be understood from the following description of some ways in which it may be carried into effect as applied to a fuel injection pump constructed substantially as de- Con- :1 scribed in the specification of one of the co pending applications referred to above. In this description reference will be made to the accompanying drawings, wherein:

Fig. 1 is a side elevation (on a smaller scale than the other figures) of the fuel injection pump with a fuel feed pump incorporated therein in accordance with this invention, some parts being broken away for the sake of clearness,

Fig. 2 is a fragmentary view mainly in section taken on the line II-II of Fig. 3,

Fig. 2A is a similar view of the right-hand end of the pump,

3 is an end view of the left-hand end of the pump taken on the line IIIIII of Fig. 2, with some parts omitted,

4 is a fragmentary view with some parts in section, the section being taken on the line Il-IV of Fig. 3,

Fig. 5 is a plan view of a valve housing mounted exterenally on the main pump body,

6 is a section taken on the line VI-VI of Fig. 7 is a section taken on the line VII-VII of Fig. 5, part of the main pump body also being shown, i

Fig. 8 is a fragmentary section substantially corresponding to part of Fig. 2 but showing an alternative form of fuel feed pump, r

Fig. 9 is a fragmentary sectional elevation il lustrating another form of fuel feed pump according to this invention,

Fig. 10 is a plan View thereof, and

Fig. 11 is a section taken on the line XI-XI of Fig. 10.

In all these figures like reference numerals indicate corresponding parts.

In the fuel injection pump shown in the several figures, see particularly Fig. 2A, the housing l is of substantially cylindrical form and has the pump barrel ti secured in the right-hand end thereof with their axes parallel with and equiangularly spaced around the axis of the housing. Pump plungers 2, the outer end of one of which is also visible in Fig. 2, are arranged in the respective barrels fill and pass through con trol sleeves t: which are mounted in a common adjusting member 52 capable of being actuated manually by means of a central axial extension carrying a rod M which is located within a tubular extension 3 of the housing and is operable by the lever 4. The common adjusting member 62 is located within the housing l close to a transverse partition 5 between which and the member is disposed a collapsible bellows 65 said space.

3 secured at its ends to the respective parts. The space within the bellows E5 is placed in communication, through suitable passages 66 and a connection 6, with the space within the induction manifold of the engine supplied by the pump, and the space 61 surrounding the bellows 65 within the housing I is provided with a restricted outlet an annular chamber 69 which is supplied with fuel through a passage 4 la (shown as a circle in broken line in Fig. 2A leading from aninlet connection 4| (Fig. 1) on the exterior of the housing I. The chamber 69 is in communication with annular sub-chambers 'lll'which encircle the respective pump barrels .60 and supply the inlets H of these with fuel.

The chamber 69 is also in communication, through a return pipe (not shown), with the fuel tank so that excess fuel will flow back to the fuel tank. Each plunger 2 is formed with an axial bore I2 extending from that end which works'within the corresponding pump barrel 6!! to about the location of the respective control sleeve Bl, at which point it opens to the cylindrical surface of the plunger through a radial bore 13'there'in. Due to this arrangement, the delivery of the pump plungers 2 is varied in accordance withthe position of the respective control sleeves 6| axially of the plungers, the bores 12, 13in theplungers being placed in communi cation with the space 61 surrounding the bellows 65 at an earlier or a later period in the strokes of the'plungers whereby some of the fuel in the respective pump cylinders will be spilled into the Itwill be understood that owing to therestricted outlet 68 from this space, the pressure of the fuel within the latter will vary in accordance with the amount of fuel spilled from the. cylinders in a unit of time, the bellows '65 being influenced by these changes in pressure to adjust the position of the control sleeves 6i automatically so that agoverning action is exerted upon'the operation of the fuel injection pump. All these details of construction of the pump. proper are fully described and illustrated in the; specification of; co-pending application Ser. No. 168,359, and require no further illustration here.

Theouter ends of the pump plungers 2 pass through respective clearance apertures M in the partition 5 within the housing I into a further chamber I which is infree communication with a chamber 8 (Fig. 2) that contains a common face cam 9 haying its axis. coincident with that of the housing! and adapted to operate the plungers 2 through sliding members It carrying rollers II for contacting the operative cam face So. The annular gap between a plunger 2 and the edge of the aperture 14 in the partition 5 is sealed in a substantially oil-tight manner by means of a suitable packing 15- (Fig. 2A). In this way, the two chambers 1 and 8 within the housing l are effectively isolated from the chamber 61 containing the common regulating member 62.

The sliding members. ID for actuating the plungers 2 are mounted in guides [2 in a portion of the housing I' which is formed centrally with a pump cylinder l3 having its axis coincident with that of the housing and having an open end directed towards the partition 5 in the latter. Within thiscylinder is disposed a cylindrical liner having-an annular. groove I5 around its exterior and formed at its inner end with slots 5 for establishing communication between the groove 15 and thecylindrical space I! enclosed by the liner. Within the latter is slidably arranged a pump piston l8 which is normally urged towards the closed end of the cylinder by a spring l9 located between the piston and an annular pressure plate 20 secured over the open end of the cylinder. This pressure plate, which also serves to retain the liner in position, has an inwardly extending flange 2| around its central aperture '22 which serves to stiffen the plate and also to position the adjacent end of the spring [9. Centrally secured in the piston 18 is an axiallyextending rod 23 having a T-shaped free end 23a, the projecting arms of which are adapted to be received in notches 24a formed in an actuating lever 24 at either side of a rectangular slot 25 within which is accommodated the adjacent shank portion of the rod 23. The dimensions of the slot 25 are such that the T-end 23a of the rod may be passed through the slot as a reasonably close fit whereupon, upon being rotated about its axis through the projecting arms of the T-portion are moved over thelonger edges of the slot to engage in the notches 24a.

The actuating lever 24 extends substantially diametrically of the housing I and parallel. with the partition 5 and at one end 2% (Fig. 3,) is bifurcated to embrace a flat-sided pin-like extension ll ia from the end of asliding member 28 (see also Fig. 4) corresponding to,,but smaller than, those used for transmitting movement to the pump plungers 2 from the cam 9, 9a. This sliding member 26 bears by its one end onthe lever 24 and has an appropriate roller 21 at its opposite end to run on the operative face 9a of the cam 9, the correct disposition of the roller being ensured by the engagement of thepinlike extension 26a with the bifurcated end 241) of the actuating lever 24. Towards its opposite end, the actuating lever is pivotally mounted at 28 on that portion of the housing which affordsthe guides for the sliding members It, 26,.and this extremity of the lever passes with clearance through an aperture 29 formed in the housing of the pump.- Closely adjacent to this aperture,

. there opens ,intothe external surface of the housing a substantially radial bore 3!] which communicates at its inner end with thespace defined between the annular groove 15 in the liner M and the wall of the cylindrical recess l3 within which this is received.

On the external, surface of thepump housing is mounted a valve housing 3| which covers both the aperture 29' andthe end of the radial bore 30. The inner face of the-valve housing is recessed to a small depth at 32 and there open into the base of the recess two passages 33a and 3411. (Fig. 7) fitted with non-return valves 33 and 3 respectively, which are adapted to close in opposite directions; That valve 33 which opens away from the shallow recess in the valve housing has the passage 33a in which it works connected by a bore 35 in thehousing to adeeprecess 36 (Fig. 6), the open end of which registers with. the aperture 29. The recess 36 is deep enough to accommodatethe projecting end of the lever 24 with adequate clearance. That valve which openstowards the shallow recess 32 in the inner face of the valve housing 3| has the passagefida in whichitworks connected to the supply pipe from a fuel tank at theinlet connection 76. The portion of the-shallow recess 32 in the valve housing into which the valvecontrolledpassages open is isolatedfrom the other portion into which the deep recess 36' opens by a suitable packing or gasket 31.

It will be seen that as the front cam 9, 9a rotates, the actuating lever 24 will be oscillated about its pivot 28 and will thus cause reciprocation of the piston l8 within the liner M. on each outward stroke of the piston, fuel will be drawn into the cylindrical space within the liner Hi from the inlet connection 16 by Way of the opened valve 34, passage 34a, recess 32, bore 30, groove l5 and slots l6. As the piston moves back on each inward stroke, the fuel in the cylindrical space within the liner 4 will be expelled through the slots I6, groove l5, bore 30 and recess 32 but as the valve 34 will now be closed and the valve 33 will now be open, the fuel then proceeds by way of the passage33a, bore 35, recess 36, and aperture 29 into the compartment 1 of the pump housing. This compartment is in free communication (by way of the passages 38, 39) with the chamber 8 which is provided with an outlet 4|) at which is connected (as shown somewhat diagrammatically in Fig. 1) a pipe 11 leading to a filter 18 from which a return pipe 19 is connected to the inlet 4| provided at another point in the pump housing to supply fuel from the chamber 8 through the outlet 40, through filter l8, inlet 4| and passage Mo to the chamber 39. Fuel is supplied from the chamber 69 through the annular sub-chamber 10 to the inlets 1| of the respective pump barrel 60 as above described. If desired the filter 18 may be omitted and the chamber 8 can be connected directly to the inlet side of the pump housing by means of a passage or passages formed in the housing.

There is rotatably arranged within the valve housing 3| a shaft 42 which extends across the projecting end of the actuating lever 24 and is formed adjacent to the latter with a diametral flat face 42a upon which the lever bears when the piston I8 connected to the lever is at the inner end of its stroke. The shaft 42 extends externally of the valve housing 3| to have secured thereon a short arm 43 suitably shaped for ease of operation by the thumb. Depression of this arm will cause partial rotation of the shaft 42 and thereby cam the end of the actuating lever 24 in the direction for drawing the piston l8 out of the cylinder. Release of the arm 43 enables the spring ill to return the piston and it will be seen that by operating the arm a number of times in quick succession, the pump may be caused to lift fuel from the tank and supply it to the inlet to the fuel injecting pumps.

It will be appreciated that other types of feed pump than that specifically described may be employed. For example, see Fig. 8, the cylindrical recess 3 may be shallower than in the foregoing example and be formed with a central axial recess |3a in its closed end to serve as a guide for a central stud 44 projecting from a disc member 45 which is in turn provided with an axially extending rod 46 whereby it may be engaged with the actuating lever 24. Between the disc member 45 and an annular clamping ring 41 secured around the mouth of the cylinclrical recess |3 is provided a flexible diaphragm r bellows 48. The radial bore 30 leading to the valve housing 3| is, in this construction, arranged to open into the space between the diaphragm or bellows 4B and the wall of the cylindrical recess l3. It will be appreciated that this arrangement constitutes a diaphragm or bellows pump which will operate in exactly the same manner as the piston pump already described.

Another construction of feed pump is illustrated in Figs. 9 to 11. In this form the cylindrical recess I3 is closed at the end adjacent to the partition 5 and is open towards the face cam 9. The liner M is inserted into the recess through the open end and is formed with an annular groove l5 with which is adapted to register the passage 30 which leads from the recess l3 to the valve housing 3|. Within the liner I4 is disposed a piston I8 which has a lost-motion connection to a piston rod 49, the rod and piston being normally maintained in the separated condition by means of springs 5|) located within the piston I8. In this arrangement the piston is actuated by means of an extension 5| formed on the pin 52 which constitutes the support for the cam engaging roller II on one of the sliding members ID. A longitudinal slot 53 is formed both through the liner l4 and the wall separating the recess I3 from the bore l2 within which the respective sliding member ID is adapted to ber I0 is reciprocated due to the rotation of the cam 9 the piston rod 49 will be similarly reciprocated and will displace the piston |8 through the intermediary of the springs 50 on the pressure strokes unless there is a tendency for the pressure of the fuel to build up to an excessive value determined by the strengths of the springs 50, in which case the springs will be compressed during the stroke of the piston rod 49.

The valve arrangements in this construction of pump are slightly different from those illustrated in Figs. 5, 6 and 7. As can be seen from Figs. 10 and 11 the non-return inlet valve 34 and the non-return delivery valve 33 are arranged in substantially the same manner as before although in somewhat difierent locations. However, the port 35, instead of leading to the deep recess 36 as shown in Fig. 6, is now arranged to open into a bore 54a formed in the valve body 3|. The mouth of the bore 54a is surrounded by a portion of the packing 31 (see Fig. 11) so that there will be no possibility of the fuel which is being delivered escaping into the recess 32. The mouth of the bore 544: registers with a passage (Figs. 9 and 10) formed through the body portion of the pump to open into the recess 8 within which operates the rise of the cam 9. It will be appreciated that the pump arrangement illustrated in Figs. 9 to 11 will operate in exactly the same manner as those constructions previously described.

It should be noted that in the arrangement last described the lever 24 has been omitted and it is not possible therefore to use the priming means which have been illustrated in Figs. 1 to 8. Since it is desirable to be able to prime the pump while the cam is stationary, a small priming pump is provided in the valve housing 3| as can be seen most clearly in Fig. 11. From the inner face of the valve housing there is formed a cylindrical bore 55 within which is arranged as a close fit a piston 56, the rod of which extends at 51 through the outer face of the valve housing 3|. A spring 58 is provided as shown to encircle the piston rod and urge the piston 56 outwardly of the bore 55 into contact with the outer surface of the main pump body, The projecting end of the piston rod 51 is provided with a loop handle 59 by means of which the piston 56 may be operated when it is desired to prime the main fuel injection pump. It will be appre- 7 ciatediithatreciprocatiom of. the primingmpistcn 56 :will qcauscriuel ztov be sucked *in: through the valverSk andszdeliverecr viathe. "shallow'recess 32 andanone-meturmdelivery:valve 33. to the bore-.54;

It wilhiot'course; be understoodthatthe ?V01u'-=' injecticnwpump plungers' for each revolution of lathe excessfuel: pumped to the inlet to" the, tea

the. ifueli pump? :proper; being 1 allowed to return to thezfueltanktin knownmannen The pumpi-constructed-according-to the inven-: w tiOnnis. particularly wcompact and :occupies- :very' littlemore space than the pumpsdescribed:inthen earlier; specifications referred to) hereimz-inr'which'z noiprov-isiorr-zwasmadez for amfeed' apump.-: The" 1 detachabi-lity. of the valve 1 housing makes zit? pos w sibleitcr adjust or clean-the valves and/ortheir seat-ing-swit-hout; amaio'r dismantling' operations: Furthermore-1th: fuel supplied-by the feed'pump to the main pump is passed through the..chami-,z-'

berlinthelatter containing: the face cam-and the.

associated working: parts which. carry. relatively heav ly loads.andipreventsi these parts being.- over-- heated. \even 'undendoadsz in-- excess: of those l'lOIr-f malforlpumps ofithisztypev.

What. Exclaim. is:

1. A .fueliinjection pump comprising a-icasing containinga yfuelchamber, a plurality vof piston-: 11 1 and-.cylinderflpumpingassemblies arranged in: a.

ring about said chamber-with their axesparallel to a-gi-venlaxis means for-conveying fuel :from saidlchamber z-to-said :pumping assemblies; a-fuel inlet --.passage.- in said/casing communicating'at onemof" its lend-s with; said-,- chamber,:' a cam: 'elemente mounted lint said-casing for rotation about saith-given axis, means fortrotating said cam element elements :actuatable by said-"cam'zelement during each-sot its rotations to operateieachof the apistons of. said pumpingassemblies in turn, a secondacham-b'er. arrangedwithin said casing substantially centrally-10f the ringiof pumping,

assemblies aasecond'passage in saideasing leadingzfrom saidtsecondchamber to the'exterior of the -casing,.-.a valve'housing: mounted on'the extee 1 riortof. saidescasingy-a fuel-supply.- connection' on saidshousing a, suctionpassage- -insaid housing leadingfromthe fuel-supply connection'to said second .npassage; c;a non-return-.:valve. located-in said" suction-passageto1 open towards said sec-, 9 ond-rpassage, .atdelivery passage in -said" housing 1 communicating-at one of its ends with SaiGSBC-J;

0nd passage, a non-return valve located in said-x1 delivery-passage-to openaway from saidgsecond' passage-ameansrfor conveying fuel; from the other of said-endsof the delivery passage to'the other of said ends of said .fnel inletpassagata:pumpe ing- ,elein'ent .ldisplacea-ble (within said; second chamber between an .end position in which said chambercan. only accommodate a minimum -volumeaof fueL and another .end.,.position in whichv 1 saidichambercanaccommodate a maximumwo1--= is arslidingv member arranged-to engage s,aid;1e,ver

*the other of-itsiextremities. 1-:

nearone'of: its extremities. 1

3. A pump 'as claimed in claimzZ, including manually :operableimeans for'displacing, the IOCkz. inglever-and. arranged ,ato. act upon the latter near;

4. A pump as claimed-in-claim ,1,- in which; the a. second=;;cham-ber-. is aFcylinder-andthe pumping elementy'is, apistoniworkingaas a close fit-in said 1% cylinders a 5. A-pumpasclaimed in claiml, in whichwlihe 4E5, pumping element is a-flexible diaphragm; x-

6. A pumpas claimedi-i-n claim 1;.in which their means for conveying fuel from, the 'deliverypas sage tor the iuel in-let passage com-prisesacham -ber formed in-xthe 'casingvto enclose: the cam-ele- 7. A pump as .claimedi in claim :1, including. a: cylinder formed in the valvechousingj to come mun-icate. with 'said second passage; a-.-piston dis placeablewithin said cylinder; andemeans oper-,.--- able from the exterior of the casing to displace said-:piston with-in its cylinder order to prime the pump:

3. A pump asclaimed in claim 1- 'in' which the 1 II actuating -.element-*is apin secured to oneof the elements .actuatable by the cam element to'oper-w ate -.the pistons of the pumpingassemblies;

9. A pump; as claimed inclaim 1', in which the secondychamber is a cylinder-, the pumping ele mentds anpiston working as a close-"fit in said cylinder, and the monnection I between the actu ating element andsaidpistonincludes ar-piston 1 rod resiliently connected with "some :lost -mot-i0n to saiclpistonl l WILLIAM FRIEDEANDER,

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