DE2154330A1 - Device for supplying fuel to the atomizers of an internal combustion engine - Google Patents

Description

BHN.5263

Ϊ1Ϊ330

Dipl. -Ict. F.-J. COPPER MAN

i'ü'-r.i.-awalt

Anr.; E: t'ar: £ 4. V. Philips Cbei'cmpenfabrfeken

File No. PHW- bZO'j
Registration from * _{2y # üicX} . , -jy γ - |

"Device for supplying fuel to the atomizers of an internal combustion engine"

The invention relates to a device

for the supply of fuel to the atomizers of an internal combustion engine, with a fuel pumping device, the inlet of which is connected to a fuel container and the outlet of which can be connected to the atomizers is, with a pressure regulating device available

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is in operation to maintain a constant fuel pressure at the outlet of the pumping device.

Devices of this type are shown in Fig. 1 of U.S. Pat. Patents 3,240,191 and 3,334,679 known. Depending on the choice of pumping device, the pressure regulating device, which ensures that the fuel is fed under constant pressure, if necessary one Pressure buffer tank (air tank) included. The mode of operation and structure of a pressure buffer tank are for example in the U.S. Patent 2,300,722.

In the case of the aforementioned U.S. Known patents devices is in the supply line an electronically controlled solenoid valve was added. The per working stroke in the cylinder of the The amount of fuel to be injected in the engine, which is in a certain ratio to the amount of fuel sucked in per working stroke The amount of air is here by changing the injection time with a constant fuel supply regulated per time unit. For this purpose, the solenoid valve is given an electrical impulse, which this valve opens for a short time, depending on the pulse duration, and fuel to the Cylinder can flow. In these known devices is through the use of by an electronic Control unit-operated solenoid valves enable precise and fast fuel metering.

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mm 4} mm

One disadvantage, however, is that a

a good mixture of the air drawn in and the fuel injected can often not be guaranteed can. This is caused by the fact that the fuel injection time is often shorter than the suction time of the air what from the following emerges.

At the maximum speed of the engine and at full load, the required amount of air is used often sucked in during and during the same time interval in which the required amount of fuel is injected.

If you now go over to partial load of the engine while maintaining the speed, then a smaller amount of air is sucked in during the same time interval as at full load. An adjustment the correspondingly smaller amount of fuel required can now only be reduced by shortening it the injection time, because of the constant fuel pressure in the supply line when the fuel is open Position of the solenoid valve a constant amount of fuel per unit of time passes through this valve.

If the speed is now also reduced, the one required per working stroke becomes Amount of air sucked in over a longer period of time, so that an even greater discrepancy between the air

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suction time and the fuel injection time arises.

As mentioned, this causes a

poor mixture of air and fuel, resulting in incomplete combustion of the Mixture and, as a result, to a low engine efficiency and dirty, harmful to health Exhaust gases leads.

The purpose of the present invention is to provide a device in which the aforementioned Disadvantage while maintaining the fast and precise metering of the amount to be fed to the motor Fuel quantity does not occur.

To achieve the desired goal, the device according to the invention has the Indicates that at least one throttle with an electrically controlled operating element between the fully open and the fully closed position continuously adjustable passage is present, with itself the throttle inlet connects to the outlet of the pumping device and the throttle outlet with a first pressure control valve is connected, which in operation a constant pressure at the throttle outlet maintains, which is lower than the constant pressure at the throttle inlet, which first pressure control valve a housing includes a fuel inlet chamber connected to the throttle and one thereof separate fuel outlet chamber between which

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a valve seat is arranged, wherein a valve body is present which cooperate with the valve seat and the passage of which can be fully or partially released, the one supplied to the control valve Fuel exerts a force on the valve body that faces away from the valve seat, and being resilient Means are present which exert a force in the direction of the seat on the valve body and which Means a small spring rate to create a flat fuel pressure-flow characteristic of the control valve have, which control valve is further formed such that the one facing away from the seat Direction exerted on the valve body forces due to the fuel pressure in the outlet chamber in relation to those due to the fuel pressure in the inlet chamber are small, with the outlet chamber connected to a manifold that supplies the various Nebulizer periodically and per nebulizer always during the same time interval with the aforementioned outlet chamber can connect.

As a result, both on the input and on the output side of the throttle during operation constant pressures prevail and thus there is a constant pressure difference across this throttle the amount of fuel flowing to the control valve can be adjusted by changing the passage of the throttle can be regulated quickly and easily with the help of an electronic control unit. The control valve ensures

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at the same time that the flow of fuel passed through the throttle does not flow through the in the Discharge of the control valve occurring pressure changes is influenced and that it is independent of it. The distributor ensures that the fuel supplied is evenly distributed over the atomizers will.

Due to the flat pressure-current characteristic of the pressure control valve, a change in the Fuel flow by changing the throttle passage minimal pressure change occurring at the throttle outlet immediately a large change in the passage the control valve result. The changed fuel flow is thus allowed through unhindered.

That the fuel in the outlet chamber of the pressure control valve is only subordinate Forces exerted on the valve body compared to the forces exerted on it by fuel in the inlet chamber Exerted forces offers the advantage that pressure changes occurring in the outlet chamber, for example originate from the distributor when alternately switching to the different atomizers, exert only a small influence on the pressure at the throttle outlet, so that the pressure difference over the throttle and thus the flow of fuel allowed through the throttle remain almost constant. The fuel flow delivered is thus practical regardless of the one facing the distributor

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Pressure changes occurring on the side of the pressure control valve,

With relatively small ones to be injected

However, fuel quantities can still cause the problem that the slight displacement of the valve body under Influence of the pressure changes in the outlet chamber too great a spread in the ones supplied to the atomizers Fuel amounts caused. Switches the distributor for example, alternately from an atomizer with spray pressure ρ to an atomizer with spray pressure ρ + Δ. ρ around, the position of the valve body changes between χ and χ + Λ x. The mentioned change in the injection pressure is caused by the production of the Atomizer occurring dimensional tolerances and one as a result occurring change in the flow resistance caused.

When switching from an atomizer with spray pressure ρ on an atomizer with spray pressure ρ + Δ ρ causes the displacement of the valve body A volume change ΔV emerges over the distance A x.

When taking up the new position

of the valve body, the constant flow of fuel originating from the throttle is momentarily an amount of fuel withdrawn with the volume ^ V, while the original constant fuel flow after the Adopt this new position during the remaining time that the atomizer with the injection pressure ρ + Δ ρ is connected to the distributor, the pressure control valve passes unhindered. Is that

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An amount of fuel with the volume V is supplied to the atomizer with the spray pressure ρ, then the atomizer with the injection pressure ρ + Δ P a quantity with the volume V - Δ V is allocated. Especially with small ones Injection quantities can result in too great an error in the distribution of the fuel over the various Atomizers are created. In order to avoid this disadvantage, there is a favorable embodiment the inventive device a second pressure control valve in the connection between the first pressure regulating valve and the manifold for maintaining a constant pressure difference between the inlet and outlet chamber of the first pressure control valve, which second pressure control valve a housing contains a fuel inlet chamber connected to the outlet chamber of the first regulating valve and a fuel outlet space separate therefrom and connected to the distributor, between which a valve seat is arranged, wherein a valve body is present which cooperate with the valve seat and the passage of which can completely or partially open and that with its from the valve seat remote side can change the volume of a further fuel space, which further space over a connection line with the fuel inlet chamber of the first pressure control valve in open connection stands, the fuel supplied to the inlet chamber of the second pressure regulating valve being one of the

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Exerts a force facing away from the valve seat on the valve body, and wherein at least one resilient element is present, which also exerts a force on the valve body facing away from the valve seat and which element has a small spring constant to create a flat fuel pressure-current characteristic of the second control valve, wherein the second control valve is further formed such that the forces exerted on the valve body in a direction away from the seat due to fuel pressure in the outlet space with respect to those due to the fuel pressure in the inlet space are.

Is now using an atomizer

Injection pressure ρ on an atomizer with the injection pressure ρ + Δ ρ switched, then both the valve body of the second move away in the first instance Pressure regulating valve as well as that of the first pressure regulating valve each via a specific one small distance from its associated seat.

The valve body of the second control valve takes one of the new injection pressure ρ + Δ ρ corresponding new position, which occurs during the time that the atomizer with the spray pressure ρ + Δρ is connected to the distributor, maintained remain. When taking this new position, the passing fuel flow is due to the associated with the displacement of the valve body

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Volume change momentarily withdrawn a certain amount of fuel. At the same time, however, becomes the same Amount of fuel through this valve body from the further fuel chamber via the connecting line driven to the inlet chamber of the first control valve and fed to the fuel flow passing there.

If the control action is sufficiently rapid, the valve body of the will shift second control valve no change in the amount of fuel supplied per atomizer.

The valve body of the first control valve returns to its original position after the deviation as a result of the switchover of the distributor to the atomizer with the spray pressure ρ + Q ρ, since the second pressure control valve after the control process the pressure difference between the inlet and outlet chamber of the first pressure control valve again constant and at the original value. If the return of the valve body of the first control valve to the original position sufficiently rapidly, the said passing flow of fuel currently extracted amount of fuel is due to the associated with the divergence of this valve body volume change of the above-mentioned stream are discharged again within the length of time that the atomiser with the Injection pressure ρ + Δ ρ is connected to the manifold. Also, this deviation, not permanent in this case, has no change in the per atomizer supplied

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Amount of fuel. Since, furthermore, through the Control process of the entire flow resistance of the two control valves and the connected atomizer is always constant, the pressure at the throttle outlet will always remain constant. The from the flow of fuel resulting from the throttle is also constant. From the foregoing it will appear that the atomizers are always supplied with the same amount of fuel.

The flat pressure-current characteristic of the second pressure control valve again ensures that a changed fuel flow is allowed to pass unhindered will.

In order to guarantee under all circumstances that occurring during the control process Oscillations are dampened within the time that a given atomizer reaches the manifold is connected, in a favorable embodiment of the device described, a damping Flow resistance added to the connection line. The amount of fuel supplied per atomizer is then always the same for all atomizers.

Another advantageous embodiment of the device according to the invention is thereby characterized in that a fuel discharge line is present, one end of which is connected to the connection between the throttle and the first pressure control valve connects and in which line

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another throttle is available.

This has the advantage that a leakage current through the unexcited throttle can still pass can be discharged through the discharge line. With another favorably chosen In this case, on the one hand, the pressure build-up upstream of the first control valve is not so great that the throttle the opening pressure of this valve is reached and the leakage current can flow to the atomizers, while, on the other hand, the further throttle ensures during normal operation of the device, that most of the fuel that has passed through the throttle passes through the pressure regulating valve and does not go through the discharge pipe.

The further throttle can

according to have a passage which by means of an operating element between a fully open and fully closed position is continuously adjustable. That way it gets an additional option for regulating the fuel flow to the pressure control valve.

According to the invention, the operating element the further throttle can be coupled to the operating element of the throttle in such a way that a reduction in the passage of the throttle an enlargement of the passage of the further throttle and that, conversely, an increase in the passage of the throttle leads to a reduction in size

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the passage of the further throttle leads. The advantage of this is that by making a small change a large change in fuel flow to the atomizers is achieved in the passage of the throttle becomes, which means a great sensitivity of the device.

The invention is based on some embodiments shown in the drawings. examples explained in more detail. Show it

Fig. 1, k and 5 embodiments of the device,

2 shows an embodiment of an electrically controlled throttle,

3a, 3b and 3c show some embodiments of a suitable for use in the device Pressure control valve.

In Fig. 1, the reference number indicates a pump device, the input of which is connected via a fuel filter 2 to a fuel container 3 and the output of which is connected via an air tank h to the input of a throttle 5, the passage of which by electrical control between the fully open and fully closed position is continuously adjustable. The output of the throttle 5 connects via a first pressure control valve 6 to a distributor 7 with a rotor 8 which is coupled to the cam axis of an internal combustion engine (not shown) and

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alternately connect the output of the first pressure control valve to one of the lines 9 during operation can. An atomizer 10 is connected to each line 9, only one of which is shown in the figure is shown. The situation shown with the four lines 9 or the atomizers 10 relates to a 4-cylinder internal combustion engine.

The connection between the

The pumping device 1 and the throttle 5 are connected to a return flow line 11 which opens into the fuel container 3 between the air vessel k and the throttle 5. A spring-loaded relief valve 12 is located in this line.

The operation of the device is as follows.

During operation, the pumping device 1 pumps fuel from the fuel container to the throttle 5. The air tank k and the relief valve 12 together form a pressure regulating device which keeps the pressure at the outlet of the pumping device or at the inlet of the throttle 5 constant at a certain value. An excess of the fuel supplied by the pump device 1 returns to the fuel container 3 via the relief valve 12.

The first pressure regulating valve 6 ensures that the pressure of the through the throttle 5 fuel allowed through at the throttle outlet

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is kept constant at a certain value, which constant pressure is lower than the constant Pressure at the inlet of the throttle. There is thus a constant pressure difference across the throttle. The through The fuel flow which has passed through the first pressure regulating valve 6 becomes uniform through the distributor 7 Distributed across the various atomizers by alternating the flow of fuel to each of the atomizers 10 is supplied during the same time interval. The quantities fed to the atomizers are then one below the other same. If the fuel flow is to be changed, a (not shown) is used Control unit that reacts, for example, to a change in the amount of air drawn in by the engine, the throttle 5 issued an electrical signal, whereby the passage of this throttle to the desired extent will be changed.

Since there is a constant pressure difference at the throttle 5, the change in the fuel flow to the distributor 7 depends exclusively on the change in the passage of the throttle. This is very advantageous because the passage of the throttle and thus the fuel flow can be changed very quickly by the electrical control, which is in contrast to such devices in which the fuel flow is changed by a change in the fuel pressure with all the inertia effects that occur.

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, As the runner of the distributor with
coupled to the cam axis of the internal combustion engine
is, the injection time of the fuel, regardless of the speed, always remains the same as the intake time of the combustion air and coincides with it, which guarantees a good mixture under all circumstances, while the amount of fuel per cylinder is always in the correct proportion to that per cylinder.
The fuel flow is always set to the correct value and a proportional part of this flow is fed to each atomizer.

This results in optimal combustion of the well-mixed air and fuel
Result and therefore a high engine efficiency and clean exhaust gases ^

The first pressure regulating valve 6 is

designed in such a way that it has a flat pressure-flow characteristic, ie that a small change in the pressure difference at the valve, for example due to a small change in the pressure at the valve inlet,
causes a large change in the flow of fuel allowed through the valve. This means that if the fuel flow changes, the new flow will pass the valve unhindered. Furthermore, the first pressure regulating valve 6 is designed such that pressure changes at the outlet of the valve
Pressure on the inlet side of this valve is practical

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cannot influence what is of great importance. That would be the change in pressure at the outlet of the pressure control valve 6, for example, when the manifold 7 from an atomizer with the injection pressure ρ switches to an atomizer with the injection pressure ρ + Δ ρ, to a change in the pressure on Entrance · of this valve lead, this means that the pressure is at the throttle outlet and thus the pressure difference at the throttle also changes. As a result, the would pass through the throttle and fuel flow fed to the manifold changed, which of course is undesirable because in the In the event that different amounts of fuel are fed to the atomizers from one another.

In which way the first pressure control valve 6 can be carried out to the two To meet requirements is illustrated in Fig. 3 using three embodiments that are shown in further discussed in more detail.

Fig. 2 shows an embodiment

an electrically controlled throttle with one between fully open and fully closed Position continuously changeable passage, as in the device of FIG. 1 is applicable. Here, the reference number 15 is a housing with an inlet chamber 16 and an outlet chamber 17 denotes, between which there is a seat 18, the passage of which is completed or more or less

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can be released by a closure element 19 forming part of an operating element 20 The operating element 20 can be moved more or less to the left and thus more or less open the passage by a more or less strong excitation of an electromagnet 21 with the electrical conductors 22. In the unexcited state of the electromagnet 21, the closure element 19 rests on the seat 18 and the connection between the inlet chamber 16 and the outlet chamber 17 is interrupted. This is done by means of a resilient membrane 22 fastened on the one hand to the housing 15 and on the other hand to the operating element 20, which at the same time separates the inlet chamber 16 from a space 23 that is in open communication with the outlet chamber 17 via a channel 2k. In the outlet chamber 17 there is also a slack membrane 26 provided with the openings 25, which is fastened on the one hand to the housing 15 and on the other hand to the operating element and is effective for guiding the operating element in a straight line.

Since the space 23 with the outlet chamber

17 is in open connection, the outlet pressure prevails on the left side of the membrane 22 while on the right side of the inlet pressure prevails. The result is a force on this membrane and thus on the control element 20, directed to the left. Likewise, a difference between the inlet and outlet pressure is applied to the closure element 19

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proportional rightward force exerted.

By a suitable choice of the effective cross section of the membrane 22 and the closure element 19 it is achieved that the aforementioned forces balance each other out. This means that the position of the control element 20 regardless of the on the throttle is the prevailing pressure difference.

The pressure control valve according to Fig. 3a

consists of a housing 30 with an inlet chamber 31 and an outlet chamber 32 between which a valve seat 33 is arranged, the passage 3 ^ by a valve body 35 connected to a piston-shaped body 37 via a valve spindle 36 can be more or less released or completed. There is also a compression spring 38, which exerts a force on the structure of the piston-shaped body 37 »valve spindle 36 and valve body 35 in the direction of the valve seat 33 and which has a small spring constant (slack spring). In room 39 there is an atmospheric pressure. The fuel supplied to the inlet chamber 31 applies the underside of the piston-shaped body 37 exerts a force on this body, which makes the structure piston-shaped body 37 »valve spindle 36 and valve body 35 in the direction facing away from valve seat 33 wants to move.

A small change in fuel

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There was pressure in the inlet cabin because of the slackness the compression spring 38 has a relatively large displacement of the structure and therefore a relatively large change in the flow of fuel that has passed through result.

Because of the great fuel pressure

in the inlet chamber 31 subjected surface of the piston-shaped body 37 compared to the effective The surface of the valve body 35 has practically no fuel pressure in the outlet chamber 32 remarkable function in the interplay of forces on the structure and a change in fuel pressure in the discharge chamber has practically no influence on the Pressure in the inlet chamber.

The foregoing is the same as before

mentioned for reasons of the constantness of the fuel flow of great importance.

When the pressure control valve according to Fig. 3b

are used for the Fig. 3 corresponding parts the same reference numerals.

The valve spindle 36 is with the

Holes 40 provided. After passing through the bores kO, the fuel supplied to the inlet chamber 31 can exert a force on a membrane 41 which faces away from the valve seat 33. Compression springs 38, formed as disc springs with a small spring constant, exert a force on this membrane in the direction of the seat 33. A compression spring kz ensures that

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the structure of valve body 35 and valve spindle 36 remains pressed against the membrane 41.

Also here is by a big one

effective surface of the membrane 41 compared to effective average of the valve body 35 ensured that pressure changes in the outlet chamber have almost no influence on the pressure in the inlet chamber 31.

When the pressure control valve according to Fig. 3c

the same reference numerals are used for the parts corresponding to FIG. 3 ^a.

The valve body 35 is designed in the shape of a piston here and on the housing via a bellows 45 30 attached. The compression spring 38 is located in the valve body 35 and the bellows 45.

The fuel located in the outlet chamber 32 can here practically only on the Cylinder surface of the valve body 35 exert radially inwardly directed forces, which the axial movement of the valve body. Pressure changes in the outlet chamber have therefore almost here does not affect the pressure in the inlet chamber.

The device of Fig. 4 is

those equal to Fig. 1 in Gressen trains, which is why Y ^ -YY -TiIx- to like parts same "tz-u-a-siiiffern. are used. Only about Ont xet difference of that, in sheet before! Iahenden case swiseäe "ά © ΠΕ first print Rege! Valve 6 and the distributor 7 s ± m.

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Pressure control valve 50 is present with a housing 51 »a valve body 52; a fuel inlet space 53 and a fuel outlet space 5 ^ ·, between which a valve seat 55 is arranged, and a further fuel space 56, the volume of which is changed by the valve body 52 with its side facing away from the valve seat 55 formed by a piston-shaped part 57 can. Between the valve seat 55 and the piston-shaped part 57 of the valve body there is a compression spring 58 with a small spring constant which exerts a force on the part 57, the direction of which is remote from the seat.

For simplicity are for parts

of the first pressure control valve 6 uses the same reference numerals as in Fig. 3a.

The fuel outlet chamber 32 of the

The first pressure regulating valve 6 is in open communication with the fuel inlet chamber 53 of the second pressure regulating valve 50, while the further fuel chamber 56 of the second pressure regulating valve 50 is in open communication with the fuel inlet chamber 3I of the first pressure regulating valve 6 via a connecting line 59. A damping flow resistance 60 is present in the connecting line 59. This device offers the following advantage in relation to that according to FIG. 1. When the distributor of the device according to FIG.

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pressure ρ + Δ P switches, so moves (see Fig. 3a) due to the pressure increase in the fuel outlet skammer 32 of the first pressure control valve 6, the structure of valve body 35 »valve spindle 36 and piston-shaped body 37 upwards and takes a new position. This is accompanied by an increase in the volume of the fuel inlet chamber 31. Accordingly, the constant fuel flow originating from the throttle 5 and supplied to the inlet chamber 31 is momentarily withdrawn from an amount of fuel with a volume corresponding to the volume change Δ V of the inlet chamber 31. After the structure has assumed the new position, the original, constant flow of fuel again passes through the first pressure control valve unhindered. If the atomizer is supplied with an amount of fuel with the volume V at the spray pressure ρ, the atomizer with the spray pressure ρ + Δ ρ receives an amount with the volume V - Δ V. If relatively small amounts of fuel, thus with a small V, are supplied to the atomizers, thus, Δ V may contain too great a deviation in the amounts of fuel supplied to the various atomizers.

This drawback is resolved in the apparatus in Fig. K.

When switching from an atomizer with the spray pressure ρ to an atomizer with the Injection pressure ρ + Δ ρ, move away in the first instance

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the valve body 52 of the second pressure regulating valve 50 and the valve body 35 of the first pressure regulating valve from their respective valve seats 55 and 33, respectively.

The valve body 52 takes a new one

A position that is maintained during the time that the atomizer is connected to the distributor with the spray pressure ρ + Δ ρ. The change in volume of the fuel inlet space 53 associated with the assumption of this new position leads to a momentary withdrawal of a fuel quantity with a volume corresponding to the volume change mentioned from the fuel flow passing through this space (on the way to the distributor 7), however, the piston-shaped part 57 of the valve body 52 transmits at the same time Time the same fuel volume from the fuel chamber 56 via the line 59 to the fuel inlet chamber 31 of the first pressure regulating valve 6, which fuel is supplied to the fuel flow passing there on the way to the second pressure regulating valve 50 .

Through suitable dimensioning

What is achieved is that the same amount of fuel as that which is momentarily withdrawn from the fuel flow in the inlet chamber 53 as a result of the displacement of the valve body 52 is fed back to this flow and has reached the distributor within the time that the atomizer is connected to the distributor with spray pressure ρ + L ρ is. The atomizer with spray pressure ρ + Δ ρ

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The amount of fuel supplied then does not differ from that the atomizer with spray pressure ρ and is not affected by the amount that occurs when switching over Displacement of the valve body 52 of the second pressure regulating valve. 50 influences. The valve body 35 of the first pressure control valve 6 returns to the original position back, since after the control action of the second pressure control valve 50 this the latter again the pressure difference between the inlet chamber 31 and the outlet chamber 32 of the pressure control valve 6 keeps constant at the original value · Made by suitable dimensioning the return to the original position so quickly that the result of the deviation of the structure from valve body 35, valve spindle 36 and piston-shaped Body 37 that passes through the inlet karamer 31 Amount of fuel withdrawn from fuel flow this stream is supplied again and the atomizer with spray pressure ρ + Δ- Ρ reaches before the connection is interrupted between this atomizer and the manifold. The current evasion of the Valve body 35 of the first pressure regulating valve 6 then likewise does not cause any change in the pro Amount of fuel supplied to the atomizer.

The damping flow resistance ensures that oscillations in the control valve system are extinguished quickly enough to allow a certain atomizer to reach the

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Manifold is connected to this atomizer the to supply the desired amount of fuel.

Because of the deviation of the valve body 35 of the first pressure control valve 6 remain the pressure at the outlet of the throttle 5 during the control process and thus also that resulting from the throttle Fuel flow constant. After the regulation process is at least for the remaining time that the atomizer is connected with spray pressure ρ + Δ ρ is, a steady state has arisen with a permanent deviation from the original position for the valve body 52 and with the original Position for the valve body 35. Switching to an atomizer with higher flow resistance had a larger passage and thus a smaller flow resistance of the second pressure control valve 5 * 0 result »so that the entire flow resistance between the outlet of the throttle 5 and the atomizer outlet remained constant. The pressure at the Drosselausgar "?: and consequently also the fuel flow originating from the throttle 5 are thus also after the Rage 1 process remained constant.

In this way is achieved ;, i- 3 ^ the atomizers when switching to atomizer off ^ r among each other different flow resistances sä; . - ■ - = each other nevertheless always the same Brenne coil quantityη be supplied by a constant flow of fuel.

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The valve body 35 of the first

Pressure control valve 6 only takes a permanent new one when the passage of the throttle 5 changes Position.

In order to ensure that changes occurring in the fuel from the lasing chamber 5 as a result of the switchover of the distributors have almost no influence on the pressure in the inlet chamber 53 or the outlet chamber 32, the control valve 50 is designed in such a way that the fuel is in the outlet chamber 5k can only exert small forces on the valve body 52 in comparison to the forces exerted thereon by the fuel in the inlet chamber 53. Accordingly, the piston-shaped part 57 is subjected to the fuel pressure in the inlet chamber 53 in Fig. K is the relatively large surface. Of course, all sorts of other embodiments of the second pressure regulating valve 50 are possible, which for example are for the most part constructed in accordance with the pressure regulating valves shown in FIGS. 3h and 3c.

For the device of Fig. K

The same reference numerals are used in FIG. 5 for corresponding parts. The device in Fig. 5 differs 4 only to the extent that in the present case the connection between the throttle 5 and the first pressure control valve 6 are connected to a fuel discharge line 65, the other of which Endo together with the return flow line 11 in the

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Fuel tank 3 opens.

In the fuel discharge line 65

there is another throttle 66, the passage of which can be continuously regulated between the fully open and fully closed positions. The further throttle 66 is coupled to the throttle 5 via a coupling 67 (not shown in more detail) in such a way that when the passage of the throttle 5 is reduced, the passage of the further throttle 66 is increased and vice versa. The further throttle 66 can, for example, like the throttle according to FIG. 2, be designed without an electromagnet. If the throttle 5 is formed in accordance with FIG. 2 in this case, the operating elements 20 can be coupled to one another.

Due to the presence of the fuel discharge line 65, the throttle 5 in the de-energized state, the leakage current can be returned to the fuel tank 3 without the risk of a such a pressure build-up at the entrance of the pressure control valve 6 that this valve opens and fuel the atomizer could reach.

The further throttle 66 increases the

Sensitivity of the device, because now a small change in the passage of the throttle 5 a large change in fuel flow to the atomizers results.

In the described embodiments

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The device has four nebulizers, each connected separately to the distributor. Of course it is also possible, for example, to connect 6 - 8 - 12 etc. atomizers, and either one at a time, or several at the same time.

209821/0594

Claims (3)

PATENT CLAIMS 1 ) Device for supplying fuel to the atomizers of an internal combustion engine, with a fuel pumping device, the input of which is connected to a fuel container and the output of which can be connected to the atomizer, whereby a pressure regulator is available to maintain a constant fuel pressure on the Output of the pumping device during operation, characterized in that there is at least one throttle with a passage continuously controllable by an electrically controlled operating element between the fully open and fully closed position, the throttle inlet being connected to the outlet of the pumping device and the throttle outlet with a first Pressure control valve is connected, which maintains a constant pressure during operation at the throttle outlet, which is lower than the constant pressure at the throttle inlet, which first pressure control valve contains a housing with a fuel connected to the throttle ffeinlasskammer and a fuel outlet chamber separated therefrom, between which a valve seat is arranged, wherein a valve body is present which can cooperate with the valve seat and partially or completely open its passage, the fuel supplied to the control valve exerting a force on the valve body that is directed away from the valve seat Exercises, and that resilient means advance are in hand that exert a force on the valve body in the direction of the seat and what means of creating a flat fuel pressure-flow characteristic of the control valve have a small spring constant, which control valve continues in such a way is formed that the forces exerted on the valve body in a direction facing away from the seat due to the fuel pressure in the discharge chamber are small with respect to those due to the fuel pressure in the inlet chamber, the Outlet chamber is connected to a manifold that periodically and the various atomizers per atomizer always during the same time interval can connect to the mentioned outlet chamber. 2. Apparatus according to claim 1, characterized characterized in that a second in connection between the first pressure regulating valve and the manifold There is a pressure control valve to maintain a constant pressure difference between the inlet and outlet chamber of the first pressure regulating valve, which is the second pressure regulating valve a housing includes a fuel inlet chamber connected to the outlet chamber of the first control valve and a fuel outlet space separate therefrom and connected to the distributor, between which a valve seat is arranged, wherein a valve body is present which cooperate with the valve seat and its passage completely or partially free 209821/0594 can give and with, its facing away from the valve seat Page can change the volume of a further fuel space, which further space has a Connection line with the fuel inlet chamber of the first pressure control valve in open connection stands, the fuel supplied to the inlet chamber of the second pressure regulating valve being one from the valve seat exerts remote force on the valve body, and wherein at least one resilient element is present which also exerts a force on the valve body facing away from the valve seat and which element for creating a flat fuel pressure-flow characteristic of the second control valve has a small spring constant, the second control valve is further formed such that the exerted on the valve body in a direction facing away from the seat Forces due to the fuel pressure im Outlet spaces are small with respect to those due to fuel pressure in the inlet space. 3. Apparatus according to claim 2, characterized characterized in that there is a damping flow resistance in the connecting line. k . Device according to claim 1, 2 or 3, characterized in that a fuel discharge line is present, one end of which is connected to the connection between the throttle and the first pressure control valve and in which line there is another throttle. 20982 1/0594 5. Apparatus according to claim h, characterized characterized in that the further throttle has a passage; by means of an operating element between the fully open and fully closed position is continuously adjustable. 6th Device according to claim 5> thereby characterized in that the operating element of the further throttle with the Bedxenungselement the Throttle is coupled such that a reduction in the passage of the throttle is an increase in the The passage of the further throttle has the consequence and vice versa an increase in the passage of the Throttle leads to a reduction in the size of the passage of the further throttle. Blank page