DE2724159A1 - FUEL PUMP - Google Patents

Description

E _e se h Reibu η gs introduction

Dia invention relates to a fuel pump r.ur supplying liquid fuel to an internal combustion engine nit internal combustion Jait a in a) ¹ Oerfiuse arranged rotary valve is in a ιuerbohrung two Pirr.ronkolL-3n is running, the one between them in the "uerrjohrung Pu'inonrauia, whereby ^ i rünla "- and ^ .uslaßörf aungen are arranged in the rotary valve and its housing, through which fuel flows to and from the pump chamber when the rotary valve is not running, v / obei further a cam ring r.it on its inside arranged cam is arranged in the housing, the cams of which act via pollen on the pistons to move them inward to deliver fuel, v / obei further a feed pump is provided, but the fuel delivers the inlet openings in the Punnanrau-n and - .: whether, finally, an actuating device actuated by pressure medium acts on the Toc'cenring, and by adjusting the timing of the fuel delivery ability to change.

The object of the invention is to design such Device in a simple and expedient manner in such a way,

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that the duration of the fuel- • L'ördoirunj au .: the Pu / .nen-kai-.imer at low operating speeds of the device can be extended canoe.

To solve the problem, for ^ i / ie device of the type mentioned before: jschlar? N, dan dij from a hydraulic ^ ruaJ -.- iitL ": -! B.rjTjf schl-vjts adjusting device one in a :: Z ' lin i = r in front of adjustable piston up; eist, v; obei via bores pressure medium acts on the inner end of the piston, the pressure of which increases with the constant operating speed of the device, in order to adjust the piston against the "effect sir ^ .r irucIiTeier, V7obei the piston has a Ka "Fn? r ciiisc'ilieRt in which an actuator in the direction uer ^ evregung the piston adjustable and is coupled with the cam ring, wherein further a spring on the actuator einvrirkt and that of de :, ^1, above piston end path, whereby a movement of the actuator against the piston end further conveys pressure medium out of the cantmer through a throttle point, and finally the arrangement is made such that the cam ring is formed with an increase in the pressure acting on the piston is adjusted against the direction of rotation of the rotary valve and the actuator under the action of the reaction force between cams and rollers relative to the

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Piston adjusted against the "action of a further spring" is such that the duration of the fuel delivery from the Puraoenraun it is extended; these Adjustment movement should be controlled by a throttle bore.

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Figure description

An example of a fuel injector g-n'in Invention is described below with reference * to the Drawing described. In: show 1 drawing

Fig. 1 is a schematic representation of a Pir.no jon'lß of the invention in section and

2 shows a diagram to explain the counting sequence the working of the P urn gsr. "..", rig. 1.

According to FIG. 1, the fuel injection pump according to the invention contains a housing 10 in which a rotary slide valve is mounted, one part of which is denoted by 11. A cam ring is also mounted in the housing, a part of which is denoted by 12 is. In the " ¹ . Rotary slide a transverse bore 13 is provided, in which zvrei pump pistons 14 are arranged, but only one of which is shown. The space delimited in the fluid bore 13 by the pump piston 14 represents a pump tank with which an axial bore 15 of the rotary valve is connected. At a point between its two ends is the axial bore 15 with several outwardly

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]: Inla3 holes in connection, dia bai circumferential Rotary valve can come to cover alternately with an inlet opening in the housing. The axial bore 15 also stands with an outwardly directed outlet hole in connection, which alternates with one of several outlet openings in the rotating slide valve Housing to cover konrut, Uin with the injection nozzles of the associated internal combustion engine in connection to become.

The pistons 14 have shoes 16 at their outer ends with rollers 17 which cooperate with crouching on the inside of the cam ring 12; one of these cams is rait 13a.

The pistons 14 are only moved inward in the delivery cycle as long as the outlet bore is in communication with an outlet opening, so that during this time fuel from the pump chamber reaches an outlet opening and then to an injection nozzle of the internal combustion engine. During the subsequent further rotation of the rotary valve, the connection between the outlet bore and the respective outlet opening is interrupted, and instead one of the inlet bores comes to coincide with the inlet opening.

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The injection pump, which is formed in \ essentially on the! Piston 14 is in rij. 1 in it sr "ssairith ^ it denotes nit 18. The fuel is fed to it by means of a feed pump 19. ~) The delivery pressure of this feed pump is controlled with a valve 2.) so that it slows down according to the speed, powered by the dia device. ^? ! ith increasing speed, the 7!> rdariruci: of the feed pump increases. The tightness of the fuel supplied to the injection pump by the feed pump between an inlet bore and the inlet opening is established by a throttle device 21.

The device is so far known.

The timing of the fuel delivery by the injection pump To be able to adjust, the cam ring is adjustable in its circumferential direction iit housing 13. These Adjustment of the cam ring takes place with a hydraulic one Adjusting device 22.

The adjusting device 22 includes a housing 23 which is fastened to the housing 10 and in which a cylinder 24 is located is located. The longitudinal axis of the cylinder 24 is tangential

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Ti cam ring 12. Within Jes cylinder 24 is arranged a hollow piston 25 which ht under the action of a prestressed compression spring 26 st ^, which is designed as a coil spring and with its piston 25 facing away from end to as ^r "in the drawing, the right end of the cylinder 24 is supported in order to press the piston 25 against its left end.

The delivery side of the feed pump 19 connects to the left end of the cylinder 24 in the drawing, so that the piston 25 counteracts the action of the compression spring 26 with increasing pressure, but only when a predetermined pressure is exceeded or reached is adjusted.

The piston 25 defines a cylinder space 27, one end of which is closed by a threaded plug 23. The threaded plug 23 serves the compression spring 26 as a jumper bearing belonging to the piston 25. A cylindrical actuator 29, which is adjustable with respect to the piston 25 and opens a radial blind hole 30, is arranged within the cylinder roughness 27. A radial tooth furnace 31 of the cam ring 12 protrudes into this blind hole 30.

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The cylindrical actuator 29 is under the action of a further coiled compression spring 32, the hollow piston is supported on the left in the drawing, line 25 and presses the actuating element against the stopper 23rd

The part that receives the compression spring 32 has a narrowed outlet. In the ZPichnunc zwai examples are shown for its design, of course, which in practice only one is used. One embodiment is a lateral flattening 33 of the cylindrical actuator 29. T.le andore embodiment is a narrow bore 34 in the partition between the cylinder space 27 and the blind hole 30. The material hole 30 is in communication with the interior of the pumping device, which is normally with the suction side of the feed pump 19 is in communication.

Zv / een the end face of the actuator 29 New York Convention the opposite end of the plug 23 there is a narrow gap 35 which is bestiixnt by means of a narrow projection of either the actuator 29 or the plug 23 and iand means of a Ouerbohrung 36 in the "piston and a Longitudinal groove 37 in the 7iu3enurafang of the piston 25 is connected to the delivery side of the feed pump 19.

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The longitudinal groove 37 is in connection with the end of the cylinder 24, which is in connection with the örd ^ rseite of the feed pump in connection,. In addition, the space 35 can via a channel 33 in the actuator 29 with the interior of the Pui -apvorriclituncr related. The channel 38 closes -sinen -ώ cut nit V3rengtar. Cross-section at then into the interspace: round f.en ^ nds, while its other end can coincide with a circumferential groove 39 in the inner circumference of the cabbage 25, as shown in FIG.

In the drawing, the delivery side G of the feed pump 19 is shown in direct connection with the end of the cylinder 24. In a practical embodiment, however, a check valve will be arranged in the connection , which prevents fuel backflow to the front of the feed pump.

The operation of the hydraulic adjustment device is as follows. The mode of operation of the pollen and cams as well as the throttle connection 33 and 34 should initially be disregarded.

The parts of the device are drawn in the position when the device is in the rest position. Begins

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the feed pump to work to deliver fuel under pressure, 30 the fuel pressure acts on the left end of the piston 25 and in the intermediate space 35. However, the fuel pressure is not sufficient to compress the compression spring 26. In addition, the pressure in the intermediate space 35 is also insufficient to steal the actuator 29 relative to the piston 25 and the effect of the spring 32. If the pressure increases further, the throttling effect in the narrowed tail of the channel 38 causes a corresponding increase in pressure in the intermediate space 35 and the actuator 29 begins to adjust against the direction of the spring 32 During this movement ^T r the connection between the channel 38 and the circumferential groove 39 is broken so that no fuel can flow out of the space 35. The movement of the actuator relative to the cabbage piston is due to the impact of the end of the actuator The broken line lashing in Fig. 2 shows the position of the locking gas 12 and actuator 29.

The arrangement is such that as the working speed continues to increase initially no control of the actuator occurs, since "but with an even higher rate

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Working speed dor pressure dsn counterpressure of the spring 26 overcomes and the piston 25 is adjusted against the action of the spring 26 wi. \ - 'a. The cam ring is thereby adjusted against the direction of rotation of the rotary valve with the result that the time of fuel delivery is brought forward by means of the IMnsr>ritz;? UripQ, if the working speed is then reduced again, the piston = r. 2! J foursome back to its starting position as shown. ~ .jz. but no fuel can flow out of the gap 35 and the pressure acting on the actuator 29 is essentially the delivery pressure of the feed pump, the actuator 29 remains together with the piston 25 at the left end 2, so that the injection time is not brought forward, ie while reducing the speed, the characteristic does not follow the broken line.

As mentioned, the interaction of the pollen with the cams of the cam ring and the effect of the constriction 33 and 34 have not been taken into account in the above consideration. ^T 7ann contrast dia rolls with a cam cooperating, the tendency will be for the Ilockenring, in the same direction as the Ilocksnring, that is clockwise in Fig. 1 adjusted to 'Verden. Such a move

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will be communicated to the actuator 29, and this will be done move to the left towards eggs ...ir!: towards the finder 27 want. During such a meeting, fuel is used Stream from the part of the cylinder rauines with the 7edar 32. However, this fuel outlet can only take place in a throttled manner as a result of the narrowed outlet 33 or 34. as The result of this is the tendency for the linear injection period, about that! ate the one introduced in ien -lockenring E-movement to be extended.

The amount of movement of the cam ring and the "tengs that The fuel supplied to the internal combustion engine are mutually exclusive addicted. For example, the pistons 14 am Have been moved outwards at the end of the intake stroke, namely only by a small amount and correspondingly little fuel has been sucked in during the intake stroke, then the usual duration of the injection time will be relatively short, and therefore the lengthening of the injection time will be due the movement of the cam ring must also be small.

If, on the other hand, the pistons have moved in accordance with an increased amount of fuel drawn in during the intake stroke moved further out, then the usual duration of fuel injection is increased, and the movement of the

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: iockenrinc; it is also enlarged, so that * $ the injection duration is lengthened by a greater amount.

The size of the strain of the Uockenringas is also determined by the speed of work of the pump is influenced, and ever The lower the working speed, the greater is the dia ßav / agung of the ITockenringes.

Abschliaßend to strongly noted warden that the fuel quantity v glsicha promoted; ird, unabliängic ^r of whether the actuator can bawagen 29 or not. If there is a movement. Ilockanringea, the injection time is long and the fuel delivery rate is smaller. Of course, this only applies while the actuator 29 can move relative to the piston 25. As soon as these two parts are in contact with one another, the dead time is reduced to that determined by the contour of the cams.

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Claims (5)

L 65 P 154 Applicant : LUCAS IITOUST ^ XIS LIMITED,! Rent Kinj Street, Birmingham E19 2ZF, England Title : Fuel Pump Pat ent entitlement _e_ 11 ·) Fuel pump for supplying liquid fuel to the internal combustion engine uit internal combustion with cineiu in c.iv.ai '. Gsh-Ta? E arranged rotary slide, which travels in ain-jr "over-bore 2v-ei Pa-cjn-3: olben, aie between itself in the puarbohruivj delimits a pump space, wob-.i inlet" ¹ , - and outlet openings in .3en .Rotary valve and sGxmn housing are arranged: i, through dia b ^ .i start '! «-'.! Rotary valve fuel to and from c.sr. Puivpanraui ¹ . flows, with a Nockinrinc πit arranged on its inside cam is arranged in the Gehr-'usa, whose lioclien over pollen on the piston pHn ^ irksn in order to move them inward for the promotion of fuel, further a Speisapur.ipe provided is that promotes fuel übar aie inlet openings in dan Punpenraur.i and wherein, finally, one of a) ruc7aiiittel-operated actuator acts on the Xocksnring to er3telluny through its ^T 'ueen Saitpunl: t be able to change the Jlraftstofi promotion, characterized in that 5/25/77 - 2 - 709849/1125 ORIGINAL IN6PECTED 2Τ24153 L 66? 154 5/26/77 .?.... - · ■ * <- 'ic of cine: pressure medium is acted upon actuator hydraulic an adjustable in a cylinder (25), said via holes Jrucknitt ^ l on the sino "r.ce Cas piston ■ eiuwirht , .Ijssan) jerk with increasing; \ rbeitsgeschwinJ'.igk ^ it .lsi "device increases, and the piston ßntgag.-in Ce.'c 7ir!: U" ij zinax . ■) rucI: .- 3Jcr (26 ) to adjust, './ob'ji l? r piston ^ inc Λάγ · ^ \ 3Τ includes, i.'i dor 3iü 3tollali.; c (29) in ^ i tuna the movement ä33 piston adjustable and. ^ .it den I ^T oc> .onring (12) gskop ^^ lt is, v; ob2i v.-eitsr -.ine Tsder (32) on the Stellglia.T a '/ irht un-Jl -Ii bSvTG from de; λ above ; Colbenen-i3 ^T ; oc, oeainflu. ^ T, ^r ,: obei ". -Time a! Movement C.33 otcllcflie .las c ^r 3; ^r 3ii the -volbsnende pressure medium from the Karoner through a throttle point (33 or 34), and finally the arrangement is so met that x \ ± t one increase of the acting on the piston.) ruc]; ss the cam ring is adjusted against the direction of rotation of the rotary valve and the St'illgliad is adjusted under the action of the reaction force between crouching and pollen relative to the piston due to the action of the further spring (32) in such a way that the oausr of the fuel Promotion from dei.i Puinpenraur is extended and that this Verstellbowbewegung is controlled by a throttle hole. - 3 - 709849/1125 BATH ORIGINAL 2724153 2. Fuel pump ccx'.ß claim 1, characterized in that ^ the actuator (29) c <i. ~ Kan: .. :: r, in which it is arranged, in z -. "?. i Tailr'iura ?. divides, v / oboi the droesalnde opening (33 \:> z ^T .r. 34) -ait le.t one that ^p .üc3: 3t3llf? vsr (32) c-ufnahnandcn VciIrau: μ is connected and your zvoitan To.ilraur (35) via bores (36) ^ pressure medium can be supplied, u: "! to adjust the 3-element axially against the deflection of its ^v "ickst? llf 3 · -Ιτ ~. 3. Fuel pump geiM- "3 claim 2, characterized in that that the second Teilrau ^. oina an "Orosselstelle has aufv / iron outflow hole (38) which The actuator (2S) is released by the axial movement or blocked. 4. Fuel pump according to ^ nsnruch 3, characterized in that that the control means for releasing or blocking the Bore (38) the end of this bore in the actuator (29) and a circumferential groove (3?) Into which the actuator leads Piston (25) is. . 5. Fuel pump according to claim 4, characterized in that that the pressure medium flowing through the bore (33) is the pressure medium conveyed by the feed pump (19). L 66 P 154 26th 5.77 - 4 - 709849/1125 BATH ORIGINAL