DE2126653A1 - Fuel injection device for internal combustion engines - Google Patents

Description

R. 293

22.4. -ι 971 Ks / Dr

Attachment to

Patent and

Gebr auchsmus t e rhi If s notion

ROBERT BOSCH GHBH, 7 Stuttgart 1

Fuel injection device for combustion engines

The invention relates to a fuel injector for internal combustion engines, especially for Hotoren with mixture compression and spark ignition, with a hydraulically driven Pampenkolben, one end face of which the pump working space and the other end face a Servo pressure chamber limited to initiate the pump pressure stroke by the fuel generated by a pressure source inlet pressure can be acted upon, with an inlet valve zv / ical pressure source and pump work space and a solenoid control valve, by which the flow of fuel from the pressure source to the servo pressure chamber and 'from the servo pressure chamber to a Return line is controllable, as well as with a spring-loaded

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209850/0514

He t Bosch GmbH. R. 293 Ks / Dr

Stuttgart

Injection valve whose opening pressure is greater than that in Pump working space occurring during and at the end of the filling stroke Filling pressure is.

With a well-known fuel injector of this type (U.S. Pat. No. 2,598,528) is controlled by a solenoid control valve one in diameter opposite the pump piston larger servo piston connected to it controlled, the stroke of which together with the stroke of the pump piston injection quantity determined. Due to its pressure ratio, this injection device is suitable for very high injection pressures (350-1050 atü), as used in diesel engines with direct injection. But it is complex and expensive and for high-speed users Motors too slow due to the slide control.

For engines that require lower injection pressures, especially Engines with mixture compression and spark ignition (Otto engines) but also diesel engines with injection pressures up to about 200 atm, "cheaper, simpler \ md fast-working injection devices are required.

A fuel injector is also known (German Patent 535 4-94 ·), without additional Servo piston works and at both ends of the pump piston The injection pressure is, however, controlled by a spring acting on the pump piston and by the Inlet pressure generated and the filling time and thus the upstream Injection quantity is controlled by a controllable throttle element counter pressure in the servo pressure chamber of the Pump piston determined during the start of injection and the

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2Q9850 / 05U

Robert Bosch GmbH E, 293 Ks / Dr

Stuttgart - - -

The beginning of the purging stroke are fixed by a mechanically driven slide control valve. This injection device has the disadvantage that due to the Eeder and the system-related long lines as well as due to the mechanical control and the pressure regulation of the counterpressure in the servo pressure chamber, it is not possible to achieve precise work that is sufficiently fast for modern motors. This injector is also a function of speed, as controlled by the perching Ijüllzeit is proportional to the speed changes and the throttle \\ ^T but not MPACT of the throttle member. Since both influences are superimposed, a constant injection quantity with rapidly changing speed cannot be maintained.

Electrically controlled injection systems with solenoid injection valves are known from Ottp-Kotoreri with intermittent injection (German patent specification 1 100 377)? in which the injection quantity is determined by timing the opening duration of the solenoid-operated injection valve. In these Hagneteinspritzventilen the injection quantity is highly dependent on the outflow of the nozzle bore, which very close eranzen ¹ DoIi required on Fertigung- this bore; and it is to be regarded as a disadvantage that a change in the outlet cross-section due to resinification or contamination of the nozzle bore leads to undesired changes in characteristics. Other disadvantages of these solenoid injectors are that if the valve seat is leaky, if the valve or the magnet get stuck, this valve will constantly inject what can lead to failure of the engine, and that with small injection quantities the atomization of the injected fuel is very pronounced is bad, because according to these small quantities, the injection times are very short. As a result, the valve needle can no longer cover the entire stroke.

209850 / OBU

BATH

Robert Bosch GmbH R. 293 Ks / Dr

Stuttgart

run ^ and through, the reduced stroke becomes the fuel inevitably due to the narrow gap on the valve seat in this case throttled which causes the bad atomization. '

These last-mentioned disadvantages are not in injection devices of the type described above; present, their? er-P Turning it around, especially in the case of gasoline injection engines, is prohibited however, because of the disadvantages mentioned above

The invention is based on the object, using the advantages of the known fuel injection device, to create a device that is particularly suitable for gasoline engines with injection, works quickly, simple in structure and is compact and cheap to manufacture, and the disadvantages mentioned of the known injection devices and . Avoids solenoid injectors.

According to the invention, this object is achieved in that both effective - -

fc / end faces of the pump piston in a known manner are of the same area that between the pressure source and the inlet valve there is an influence on the filling time and thus the injection quantity Throttle member arranged is ^ and that the inlet valve through a spring is biased to a valve opening pressure,. that together with the maximum filling dx-uek in the pump work space is at most equal to the fuel inlet pressure, which in turn is greater than the opening pressure of the injection valve. This is an extremely simple structure without additional Servo piston reached and a safe and fast operation of the injection device guaranteed.

Also, this facility has

209850 / OBU

Robert Bosch. GmtH R. 293 Ks / Dr

Stuttgart

the advantage that the filling time, which is significantly longer than the injection time (e.g. 7-fs-ch), enables a correspondingly greater accuracy when metering the injection quantity. Due to the extended filling time, even very small injection quantities can be controlled very precisely, as they are e.g. B. in the known and previously mentioned solenoid injectors according to the German patent Ί 100 37Ί are difficult to achieve. The subject of the invention also has the disadvantage of poor atomization in the case of small quantities

remedied, and indeed. even 'for even smaller injection quantities

this well-known
than they can be reached at / valves, because the pressure of the injection quantity delivered from the pump piston to the injection valve is independent of the lift height. This results in a defined jet length with good atomization even for the smallest quantities, the jet length being independent of the speed, which also applies to all other injection quantities.

An advantageous embodiment of the invention results in that the largest permissible injection quantity is determined by the largest possible stroke of the pump piston. So is exceeding the permissible fuel injection quantity not possible. This is of great advantage, especially in the case of diesel engines, if they have the largest permissible injection quantity is equal to the full-load injection quantity. This is the dreaded

en

tete and in view of the requirement / and legal provisions to keep the air clean, prevents the inadmissible discharge of unburned exhaust gases in the event of excess fuel.

A further advantageous embodiment of the invention is such that the filling time and thus through the throttle member

209 850/0514

Robert Bosch GmbH 'E. 293 Ks / Dr

Stuttgart

the filling stroke at the maximum permissible speed for the entire time between the end of injection and the start of injection of the next work cycle is expandable. This achieves an automatic safety regulation because the Exceeding the maximum speed occurs automatically Reduce the injection quantity, because as the speed increases, the purging time is no longer complete "" Pulling the jump work area is sufficient.

This enables the fuel injection device according to the invention to work particularly quickly in an advantageous manner achieves that the solenoid control valve is a known per se Pressure-balanced, electromagnetically operated 3/2-V / ege valve with a ball as a valve member (German Offenleguiigsschrii-1 934-212). The small moving registers of the valve allow an almost instantaneous switchover, what a fast urä exact operation of the valve is desired.

Three exemplary embodiments of the subject matter of the invention are shown and grounded in the drawing on an enlarged scale described in more detail below. Show it:

Pig. 1 shows a section through the first embodiment of a ¹ , pump-nozzle - the power injection device,

Pig. 2 shows a section through the second exemplary embodiment of a Pump nozzle,

Pig. 2a a section from Pig. 2 with the pump piston drawn in its lower dead position,

Pig. 3 shows a section through the third exemplary embodiment of a pump nozzle and

Pig. 4- a diagram of the injection _{quantity Q E} as a function of the injection, flushing and control times.

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Robert Bosch GmbH E. 293 Ks / Dr

Stuttgart

The first embodiment of a pump nozzle 9 ^{1 of} the fuel injection device according to FIG. 1, consisting of two assemblies 10, 11, is provided for the manifold injection system of an Otto-Hotors and is screwed together by means of a clamping nut 12 to form a cohesive unit. The first assembly 10 has a housing 13 which receives a solenoid control valve 16 in a receiving bore 14 in extension of a transverse bore 15 and which also has a hydraulically driven pump 17, which essentially consists of a cylindrical pump piston 19 guided in a cylinder bore 18, an inlet valve 21 and a throttle member 22.

The second assembly 11 consists of an injection nozzle 23, into which an outwardly opening injection valve 24 is inserted is. The injection valve 24 has a valve body & r 25, a valve needle ci6, a closing spring 27 and a spring plate 28, which is connected in a known manner to the valve needle 26 and which has one abutment for the closing spring 27 forms. The other abutment is the valve body 25

The inlet valve 21 has a valve member 31 and a valve spring 32, which the valve member 31 on a valve seat 33 pushes and thereby in a depression 34 of the injection nozzle 23 supports.

9
The housing 13 of the Puxape nozzle has an inlet bore 35, to which a Z ^^ laιlfleitung 36 is connected, which _{supplies the pump 17 at an inlet pressure p z} fuel from a pressure source 37. The pressure source 37 and the associated components are generally known and are therefore shown in a simplified manner.

209850/0514 BAD; Oriq _INal

Robert Bosch GmbH E. 293-Ks / Dr

Stuttgart

This pressure source 37 can, for example, be a gear pump driven by the motor, the delivery pressure of which is controlled by a Pressure regulating valve 38 at the desired inlet pressure, e.g. ρ = 5 atü, 'is held. To compensate for pressure fluctuations, the pressure control valve 38 can be combined with a pressure accumulator none, the structure of which, like that of the pressure regulating valve 38, is known and is therefore not shown in more detail is.

The solenoid control valve 16 described in detail below steuert'den flow of fuel from the above des'Pumpenkolbens ^f or a GorvodruckrauEi 39 19, the length of the maximum stroke IL, _r, and hence the maximum permissible Einsj> rit5i- amount Q _{I T! £ r.} certainly. The maximum stroke II can also be determined by inducing a stop 41 or shortening or lengthening the cylinder bore 18.

In the position shown, the pump piston 19 rests with its upper end face 40 on the upper stop 41 and its the. Stop 41 facing away from the lower end 42 boll borders a Purapenarbeitsrsum 43 adjoining the cylinder bore 18 upwards, while its lower limitation is formed by the injection nozzle 23, the upper end face of which forms a lower stop 47 for δ en pump piston 19. A connection bore 44 leads from the pump working chamber 43 to the injection valve 24 of the injection nozzle 23 and a lateral inlet duct 45 enables fuel to enter from the inlet valve 21. The throttle member 22 is screwed into a filling bore 46 which branches off from the transverse bore 15 to the inlet valve 21, and its flow cross-section influences the inlet speed.

209 850/05 14.

Robert Bosch. GmbH R. 293 Ks / Dr

Stuttgart

speed of the fuel to the inlet valve 21 and thus to the pump work council 43, ie it determines the filling time t- ^ of the pump-nozzle ^ by the substantially extended filling time by the throttle member 22 compared to the injection time t _E considerably (e.g. 7-fold) t- ™, a correspondingly greater accuracy when measuring the injection quantity Q is possible. Thanks to the extended milling time t ™, even very small injection quantities (now less than 3 per stroke) can be controlled very precisely.

The solenoid control valve 16 inserted in the housing 13 in the receiving bore 14, shown in a simplified manner, is a pressure-compensated 3 / d-way valve operated by an electromagnet 51, known per se (deutsehe 0f f enlegunn; ssehrif t 1 934-212) with a a valve housing 52 and a ball 53 as a movable valve member .. This ball 53 includes in the Fig. 1 illustrated position a valve seat ^l ~ a at the liüiidung a longitudinal bore 55 and thus blocks the supply deo fuel from the pressure source 37 for Servodruckraun 39- Simultaneously the servo pressure chamber 39 is connected to a return line 58 via a second valve seat 56, which is open in the position shown, and a return bore 57. The return line 58 returns the returning fuel to an oil tank 59 without pressure, from which the pressure source 37 sucks in the fuel via a suction line 60.

The electromagnet 51 has an armature 61, which is in extension the longitudinal bore 55 in a bore 62 in the valve housing 52 Is guided and with a mandrel 63 under the force of a Spring 64 presses ball 53 onto valve seat 54 when the Electromagnet 51 is in the de-energized state. To the closing

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-Robert Bosch GmbH E. 293 Ks / Dr

Stuttgart

To be able to keep within limits by virtue of the spring 64, the solenoid control valve 16 is pressure-balanced in that the inlet pressure p "prevailing in the transverse bore Ί5 is passed through a channel 65 behind the armature 61 into a space 66 accommodating the spring 64. The areas on the ball 53 and on which are acted upon by the pressure of the fuel. AnIver 61 are the same, so that the forces exerted on the ball 53 in opening and closing are also the same. Therefore, only the additional force of the spring 64 acting in the closing direction needs to hold the ball 55 on its seat 54.

The electromagnet 5'I has a control winding 67- As soon as this is energized, e.g. B, via an electronic Stouergex-ät 68 ("EiUr hinted at -largesteiled"), the power eier! «" E-der 64 is overcome and the anchor 61 is sucked in. The after-dissolving Kx-af L-material pushes the ball 53 on the second of LiI seat 56 and the K-icaftstoff can from the transverse bore 15h ^ r- through the longitudinal bore 55 and the first valve seat 54 of the ITagiietsteuorvontil 16 in the servo pressure rail 59. The lower iiohen different Dx ücken projecting portions dos VontilgeliäusGB ^l} 2, in the stepped Aui'iirihraeboiiryris

sealed against each other by sealing rings 65,69 ^ i69b.

The Rirape 17 and the injection nozzle 23 with injection valve 24 as well as the inlet valve 21 and the throttle member 22 nuts not, as shown in Fig. 1, contiert separately from one another be ^ but can also, like the second execution

.one pump-you: · & 9 '

example / according to FIG. Z shows, be combined in assemblies 71 and 72. The assembly 7 ^ ^na * ^e i ^ i pump housing 73 which is screwed into the housing 13 'and which guides the pump piston 19' in a cylinder bore 18 ', the upper "stop of which is an annular stop 41'. The pump piston 19 'has on its circumference parallel to the longitudinal axis a

209850/0 5 U - -η--

Robert Bosch GmbH E. 293 Ks / Dr

Stuttgart

lüitungsltanal. 74, the length of which is adjusted so that the vent channel 74 in the Pig. 2a drawn lower dead center (U ^- T) of the pump piston 19 '»in this en his. lower stop 4-7 * is applied, a throttle gap a. nit the upper, delimitation of the Puiipenax'arbeitsraumes 43 'forms. The double-sided gap a is only a few tenths of a millimeter wide, about 0.1 to 0.2 mm. However, this small width is sufficient to allow any steam or air bubbles that may be formed to escape from the pump working space 43 'into the servo pressure space 39'. From there, when the solenoid control valve 16 is in the closed position, these bubbles are entrained by the fuel flowing back to the tank, so that both the servo structure 39 'and the valve structure 43' are vented. When the fiiii or - AuiVärtshub the pump piston ^ 19 'begins, the narrow Drossolspalt a and thus the ventilation channel 74 is immediately "closed, so that the ventilation tungelzaiial 74 has practically no effect on the kill since t ^," The lower face 42' of the xunpeDiücolbena 19 'seals the Yerbiiidirngsbohrnnp 44' between Pun'perjar-beitsraun 43 '"and the injector 24 / αγΪ a Plachfsitz-ol vo3i ^J s from, fo that a Durclidrin ^ on of ILr aft material zv: i ^ ■: i.2isrj3- it-yvo: -itii 24- changes wixtl, sc3.ange dex- Pampenkolben ■ \ -) 'ar: Ar-sciilag 47' is applied.

The Linspritzventil 24 is in the lower roup TiBiI of luripenrehäunoü 73 üingesetxt.Die second Eau ^ 72, which in the closed »1 sufbo} i: -sy irr i .st einceschraubt 55 ', includes a ZUI the valve to ~ 21 in FIG . ^ 1 corresponding inlet valve 21 'rj.it valve spring 32' / "aJ.s throttle gliec a throttle hole 7 ^l ),

Vpn inlet yontil 21 'leads an inlet hole 76 over the Inlet channel 45 'in the pump housing 73 to the rag work room 43 '.

209850/0514 _{BAD 0RlGiNAL}

Robert'Bosch GmbHR. 293 ICs / Dr

Stuttgart. .. ■

In the receiving bore 14 'in an extension of the transverse bore: .Ί5 ¹ is as in the first * AusfühiTingsbeispiel after I ⁷ Ig. Λ the solenoid control valve- 'i6 inserted and to the inlet hole. 35 'and return bore 57' are connected, as in FIG. 1, supply line 36 and return line 58. The pressure source 37 connected to the inlet line 36 with pressure control valve .JO. and the tank 59, into which the return line 5 ^ opens - and from which the suction line 60 emanates, are the same as W in Fig. i and therefore not shown in Fig. 2, ..

The third embodiment according to FIG. 3 is a pump nozzle for fuel injection in diesel engines. These Pump nozzle '' differs essentially from the

O'
Pmape nozzle ^ according to Fig. 2 by a modified one. Assembly 71 "? ■ which has a longer housing 73 ' ^r " screwed "into the housing 13, to which an injection nozzle 23" is sweptly clamped by means of a chuck 12 "in a manner similar to that in the first exemplary embodiment according to FIG. at the upper ».. impact of Puiiipenkolbens 19 is shown in FIG. 2, an annular stop 41 'and the Puiapengehäuse ^{73! t} has a woseiitlieh longer connecting bore 44' between soineia beitsrauKi 4-3" and the injection valve 24 "as the housing

9 '
73 the. Puiape nozzle in Fig. 2. The injection nozzle 23 "contains an injection valve 24"', the valve body 25 "of which has a valve needle 26" and which is held by a clamping sleeve 78 in a bore 79 of the injection nozzle 23 ", Ar The lines 36 and 58 are a pressure source (not shown) of known design with the associated components connected as shown in FIG Just like the pressure source, the inlet valve must also be

209850 / Q51

Robert "Bosch GmbH" E. 293 KS / Dr

Stuttgart.

2'i "with valve spring 52" and throttle bore 75 "of the second Assembly 72 "and the injection valve 24" to the high Pressures to be adjusted. The solenoid control valve 16 is the same as in the Pig example. 1 and is detailed there described. This pump nozzle can also be used accordingly lower pressures can be used for direct injection into the combustion chamber of a gasoline engine.

All three embodiments of the fuel / tl '^' S · 1 d-: ls 'j)' "" work only if, according to the invention, the valve spring 32,32 ', 32 "of the inlet valve 21,21', 21" on one Valve opening pressure py is biased, which together with the maximum filling pressure p- ^ v in the pump working chamber 43, ^ 3 '»43" is at most equal to the fuel inlet pressure p ^. In addition, the filling pressure pjBiax must remain smaller than the opening pressure

of the injection valve 24.24 ". For an intake manifold injection in Otto engines, the pump nozzle works according to FIG. 1 or reliably if, for example, Pr _7-5 atm, p _Tr = 2.4 atm,

is ν qit

Pjjaax = 2.6 atm and p «= 3 atm. The pump nozzle according to FIG. 3 works, for example, with the pressures p _z = 200 atm, Py = 80 atm, p-jjnax = 120 atm and pq = 150 atm. The maximum auxiliary pressure pp max in the pump working space 43, 43 *, ^ 3 "only occurs when the pump piston 19, 19 'remains at its upper stop 41, 41', 41" for at least a limited time; because then the pressure p "in the pump working space 43" rises as long as until p - ^ + Py = P ₂ ; is.

In Fig. 4 are'inr the lower part of the diagram, the course of the Stroke H of the pump piston 19, 19 'and thus the injection quantity Q plotted as a function of the filling, injection and control times (t-p, t-g, to). The largest possible injection quantity For example, Q ^ (highest point of line A) becomes

with stroke H ^^, ^ and with a filling time t ^ of 25 milliseconds max above

(ms) achieved, the associated injection time tg is 3? 6 ms.

Both times correspond to 315 ° or 45 ° cam angle (NW),

2098E0 / 06U _offlQ , _NÄL _, ₄ _.

Robert Bosch GMBH
Stuttgart

which together result in 360 ° E cam angle, ie one revolution of the · * ":. ■ - *"'" camshaft. With a 4-stroke engine, one: camshaft revolution corresponds to two revolutions, of the crankshaft =. 720 ° crank angle (KV). Injection - and filling time. (t ^ + tp): together result in the example according to the line A together. "28.6 ms, which corresponds to the cycle time T of a working cycle of the motor at a motor speed η = 4,200 revolutions / min ; because

^rj} = 2.60 ■ - 2.360 = 28.6; 10 " ⁵ sec. = 28.6 ms. T = tp + t ^ ■. - · -. 4200 UT ² PSUO.. - ^

only applies if xvemi at to the filling begins at the same time as the end of the injection. ,. _:

The smaller injection rate GL (partial load injection quantity) is achieved with stroke -_EL · and with a course of -injection according to the dashed line B. The associated filling time is tjpy, and the corresponding injection time t-rv ,. The injection quantity Q ,, belongs to the Puiopenkolbenhub H-. In the illustration according to FIG. 4, it is assumed that the speed η = 4200 revolutions / min also exists at CL, namely a lower speed would result in a correspondingly longer cycle time T (not shown). Between the end of t- ,. and the beginning of tp. is the pump piston 19? 19 'during the rest time t _Ry , at its lower stop. In this case, the cycle time T is composed of t- _a ^ + t- _ny . + T- _rx ^ . The switching times of the.

Electromagnets 51 of solenoid control valve 16 are shown by the solid line C for the greatest possible "injection" narrow Q and by the dashed line D for the partial load injection quantity Q. At G 1 and D, the valve 1-5 is in its closed position , at C ^ or Dp in its open position. The beginning and end of the switch-on times t "and ^r ." kg ^ i determine the start of injection t ^ and the. Beginning of the filling stroke tp or t ^. The time between two switch-on times tg or t _q ^ ,, in d.er_ the solenoid control valve 16 is de-energized and in.

209850/0514

Robert Bosch GmbH R. 293 Ks / Dr,

Stuttgart. - ■■ -. ■■

its closed position C, - or. D. is designated as the switch-off time with t * or tj>. The point in time at which the fan spray ends is designated by tp or t- and is essentially only based on the upstream injection quantity Q. or (L · , because the other influencing variables, such as the addition ·

DsLi "'I

The running pressure p _z and the parameters of the injection valve 24, 24 ″ are constant. The fuel inlet dx-uck p ″ can, however, if desired, be changed to change the length of the injection time within limits, for example as a function of the speed.

In the following vri. About one operation of the inventive Einsp:

a f during a work cycle T of the engine based on the 1 and 4:

Before the start of the injection, the full throttle Q _n . "(See lines A and C) the pump piston 19" is at H, _r a \ if ~ due to the previous filling stroke at its upper stop 41 (TDC position). At t, - the I-Tagnet control valve 16 switches from the closed position CL into the open position Cp, while the ball 53 jumps from the valve seat 54 to the second valve seat 5S, and the fuel delivered by the pressure source 37 _{under inlet pressure p z reaches the ßervodruckrcvun 39 5} acts on one end face 40 of the pump piston 19 and drives it downwards until its other end face 42 hits its lower stop 47 at time tp to the injection valve 24 of the injection nozzle 23- Since the fuel supply pressure p, ~ acting on the upper end face 40 of the pump cage 19 is greater than the opening pressure p * of the injection valve s 24 that

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BAD ORIGINAL 209850/0514

Robert Bosch GmbH E. 293 Ks / Dr

Stuttgart

Inlet valve 21 is closed and p "during the downward movement of the pump piston 19 also in. The pump work chamber 23 acts, the injector injects the 23 supported by the lamp bulb injection quantity Q _ma ^ - (not shown) i ⁿ a known manner into the intake manifold of a Hptors. At the point in time t dos the end of injection, the magnetic control valve 16 switches back from its open position C _n to its closed position C after the switch-on duration t ". Now the ball 53 blocks the fuel supply to the servo pressure raua 39 ^υ - ^η ^ - relieves the latter via the now open second valve seat 56, via the bore 62, return bore 57 and return line 58 to the tank 59 Inlet valve 21 opens and the fuel flows into the pump chamber 43 with a filling pressure p ™ reduced by the throttle element 22 and the inlet valve 21. This flushing process runs between tp and t. in the flushing time ι, -, from, to at t. the solenoid control valve 16 switches back to the already described switching position C ₀ and the next working cycle T begins. In this case the fill time tp is equal to the switch-off time t-. of the solenoid control valve 16. .._ * - ·

When the partial load injection quantity Q ^ is conveyed according to the dashed lines B and D in FIG. 4, only an injection quantity Q. corresponding to this stroke has been placed in front of _{the filling time t-jj, ^. Between t 1 and t x with a stroke EL.} In t., If the Kogiict control valve 16 switches from B. to Dp, the injection stroke begins and ends at t.,. Until the end of the switch-on time tg ^ at t ^, the pump piston 19 remains at its lower stop 47 during the rest time t ™. Kit switching the solenoid control valve 16 from its open

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098507051 ^

Robert Bosch GmbH R. 29 ^ Ks / Dr

Stuttgart -

position D ^ in its closed position D. at time t ^ the filling stroke begins in the filling time t ™ up to the point in time t, j expires. The next injection begins at t and the process described is repeated *

The various embodiments of FIG. Λ bio 3 show only one pump nozzle 9i9 '> 9 "of the fuel injector. Of course, the fuel injection device, in the case of installation on multi-cylinder engines, a correspondingly greater number of pump nozzles have, each diesel? Pump - Nozzles, as is known, can only serve one or several cylinders _x

209850/0514

Claims (3)

Eobert Bosch GmbH ~ 'E. 293 Ks / Ds Stuttgart claims 1.) Fuel a fuel device for internal combustion engines, especially for rotors with; Gc-miselive and spark ignition, rait a hydraulically driven lamp bulb, one end of which delimits the pump work space and the other end of which delimits a separate pressure space, which can be blown through to initiate the furapend pressure through the fuel generated by a pressure cylinder an inlet valve between the pressure source and Puiapenarbeitsr-auia and a liagjietstcucrvent.il, through which the flow of fuel is "from the pressure source to the servo pressure rauiri and from the servo pressure rauiri to a return line ^{: is} controllable, as well as with a spring-loaded injection valve, its offramgsdruck is greater than the ilillpressure occurring in the pump work roughness and at the end of the filling stroke, characterized in that the viirksaXierL
that (both front sides (40, 42, 42 ') of the piston piston (19, 19') have the same area in a manner known per se, that - 19 - 209850/0514 Robert Bosch. GmbH R. 293 Ks / Br Stuttgart between the pressure source (37) and the inlet valve (21, 21 ', 21 ") is a throttle element (22.75» 75 ") which influences the filling time (tp) and thus the injection quantity (Q)? and "that the inlet valve (21, 21 ', 21") is biased by a spring (32} 32', 32 ") to a valve opening pressure (py) which, together with the maximum ϊΓυli pressure (p.jna: :) in pump work ravffii (43 /! 3 '»4-3") is at most the same as the fuel inlet pressure (Pr ₇ ), which in turn is greater than the opening pressure (p «) of the injection valve (24.24"). 2. fuel a spirit z device according to 'claim 1, characterized in that üie greatest allowable injection quantity (Q_ ^) determined by the largest stroke (H) of the pump piston ( ^Λ 9 _Ύ '"'9'); 1 st « 3. Fuel injection device according to one of claims 1 o elco * 2, characterized in that the EüllzcJt (t _i7 ) and thus the Füllira at taxi Ei al permissible speed (n ^) ^{through the throttle member (22,? 5.75 U)} the entire time between the end of injection (t2) "and start of injection (t ^) of the next work ext. it is expandable. BAD ORlQiNAL 209 850 / 05U Fuel injection device according to one of the preceding Claims, characterized in that the solenoid control valve (16) a pressure compensated known per se, solenoid operated 3/2-way valve with a ball (53) as valve element i§t * Fuel injection device according to one of the preceding claims, characterized in that the pump piston (19 ¹ ) has a ventilation duct (7 ^) through which
when the Purape piston (19 '.) is in contact with its lower one
The stop (4-7 ¹ ) of the pump working space (43 ¹ ) can be connected to the servo back space (39 ¹ ) via a narrow throttle gap (a)
is (! 'ig. 2a). 209850 / 05U Blank page