DE2704171A1 - METHOD AND DEVICE FOR SUPPLYING A COMBUSTION MIXTURE TO A COMBUSTION ENGINE - Google Patents

Description

? ATENTAN WALTE 2/04171

DIPL.-ING. ALEX STENGER

D-4000 DÜSSELDORF 1 - DIPL.-ING. WOLFRAM WATZKE

Malkastenstrasse 2 ^ DIPL.-ING. HEINZ J. RING

Our drawing: IY 6'jC ") Date: February 1st \ ⁽ ) '(' (

Edv / ard Davies, d [> Victoria Road, Catseldale, ÜPRItJGS, Transvaal Province, South Africa

Decay and device for supplying a combustion mixture to an internal combustion engine

The invention relates to the fuel supply for combustion amotoren and especially the supply of such motors with a combustion mixture of air and hydrocarbon fuel. GLe specifically has a method as its subject and a device for supplying such a mixture to an internal combustion engine, part of which. Fuel liquid and another TnLl gaseous i:; t. Particularly doubted the invention reduces air pollution by providing the internal combustion engine with a combustion mixture of air and a combination of fuels i ', ui; e introduces vitrd.

In Gobieten in which are operated with horkünimlichen liquid Kohlenv / asaerstoff fuels vehicles in large numbers involved in the volume of traffic is increasingly an air pollution verzeichnen.Überall there, v o the vehicles are often forced to pause and restart, with The likelihood of air pollution exceeding the respectively acceptable limits is to be expected, especially because the mixtures fed to the engines of these vehicles are only incompletely burned. Frequent stopping and driving of the vehicles and throttle valves that are opened too wide at certain engine speeds result in mixtures that are too rich, since the supply exceeds the respective fuel requirements of the machine.

In the following description, the term "gasoline" (gasoline) including those liquid coal

-A-

709832/0686

Ttltfon (0111) M OS1 «■ relrgumm» Jr «JM: Dabtpatcnt · PotUditiUonto Cologne XlJi 10

~ l ~ 27OA 17

wa.sijertitof f-Kraftntof fj, './Le χ Ίο Ία some IOi Leu of the woman also aib "PetroL" (Henzin) known and.

Task of the before He ^ onclen invention L ;; U uü, the air pollution unites by creation; Air, - Fuel-VerbronnuncsijemLiiehr, for Internal combustion engines to vert · Lucern, since ;; Lu sol.ehen; ', ofcor;.'; I 70IL-t; t auditor burns aiü the:.; in the case of the previously known fuel inü ^ i was.

Dati eri'indunf; i3 ^ emäüü Veri'aiirüii t'Ur the 'Zui'uhr einer Verbrennunijs [iomiijcl] i> lii ^ binem: nit t'LUüKi ^ ei ^ iohLuiiViaüi nfcotT operated and equipped with a throttle j; means:

a reduced / ui'ithr of _fLiUuJi: em KohLenwaüüerütoiT-iiraft otoi'i "to the engine;

the company de :; Engine:; with the · to _(-ei'ührten reduziorten L-'LlUjiiitfkrai'tiitot'i'inciujo, v / odiu'cii a Lut'tiitrom to flotoi · causes v / ill;

Precautions for the supply ¹ of FLüf. ^ I ^ gas in Uaüforiu ait; iLi'gäii / untjükr'at'tatoi'i ', the Ln dependence on liier voi'c neti Mindeüt-liUi'tmen ^ e im I, iii't. ^: Jtrom in dieiien aücypüiist

Supply deu ür ^ riiizun ^ iikraftiJtoffii Ln den iuiftiitroai Ln ", unehmen the quantities of air in the air stream.

Like gasoline ((lanolin, Put ro L), aucti Küisüi ^ gas is an i.oliLenuasiJui'Gtoff-Kraftutoff, mainly think of Uutan or Tropane or a (JeuiL.soh die:; ui "(l; use üiiid. Under normal atmospheres Uetlingun ^ en Lt; t ο -> gaüTörmi ^, while petrol under ümiLchen Verh ^: iitniiJüen l'Lüsüi ^ Lr ₃ t.

DLe l'ul'ulir von Er ^ üiu'.un ^ fuel to the engine! Rann aucti iiur then before ^ esclien v / erden, ', lana eLii Uiiterdruck von llölie Lm l.iii'tutroin occurs.

The Ileduziei'unt ¹ ; the 1 ' ¹ LiUiUitskraftatoffmen ^ e _{to LJ eflirten 7oLumenm; iiiL t} ; ütv; a I ■ S> bLt: 1.2. LeL eLnem Vertjasorniotor Laut uieh die:; e Veri'in ^ uriui) ¹ ; by VurMcLeLnern dec Durohniu:; £; uri; dei * diiiju de :; ilotors um jtv / a L / ^ ei'reLciien.

709832 / 0G86

The relative proportions of supplement and liquid fuel are adjustable by reducing the amount of liquid fuel used during operation the throttle is opened to a predetermined extent and then the amount of supplementary fuel supplied is adjusted until the motor is running at the rate for the respective throttle - ("ffnun-j 'Tiaximal speed is running.

The xJri'inüun.2 also relates to a supplementary fuel supply system :. for an internal combustion engine with an air inlet and a throttle to control the air flow to the Ilotor in the area de. ^c >Lul'tcinlasses, vjclclies contains:

A fuel tank for storage of supplements: ra ft substance in the form of liquid; in liquid and gaseous form :: usta:; d under a Di'uck that v. "j tones borrowed above the atmospheric DiMCk llöL't;

An iir ^ - 'in ^ ungG fuel supply line from the tank to ^ u'ii engine air intake;

a pressure reducing valve in the supply line for pressure reduction dec supplementary fuels in the tank to a low; i above atmospheric pressure ;;; ends up in the supply line do; r;

a counter for detecting the predetermined throughput of supplementary fuel in the supply line under a predetermined one Pressure and

a supplementary fuel supply valve in the supply line, which only opens when there is a negative pressure of a specified level in the air flow to the engine and corresponding to a minimum amount of air occurs in the air flow, and the feeding of increasing amounts of supplementary fuel into the air flow as a function of allows and enables increasing amounts of air in the air flow.

The supplementary fuel Versoismgsleitung can be designed be that the supplementary fuel is liquid from the container in she kicked; there can be relaxation devices, pressure reducers and heaters to compensate for the chill are provided.

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The system can be equipped with a lock, which only then allows the supplementary fuel supply valve to be opened allows when a specified minimum amount of air to the engine flows. The lock can contain a stop which is biased into an operative position in which the supplementary fuel supply valve is opened is prevented, and a suction connection to the air inlet of the engine to the stop in a To transfer rest position, in which the supplementary fuel supply valve can be opened.

The invention will now be described using exemplary embodiments with reference to the accompanying drawings; from the drawings shows:

1 shows a schematic arrangement of a supplementary fuel supply system, in which the supplementary fuel is taken from a storage tank in the liquid state,

2 shows a schematic section, which shows the feeding of supplementary fuel into the fuel fed to the engine Air flow shows

5 shows a schematic representation of a detail of a flow regulator, is part of the system according to FIG. 1,

Fig. 4 is a schematic section of the component the filter lock forming the system according to FIG. 1,

Fig. 5 schematically shows a further embodiment in which the supplementary fuel is taken from the tank in a gaseous state and

FIG. 6 shows a schematic view of a flow regulator forming part of the system according to FIG. 5.

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'* - 2 7 O 4 17 1

In the drawings, the reference numeral 10 denotes generally a supplementary fuel delivery system with a supplemental fuel tank 12 and a supplementary fuel supply line 14, through which fuel in full-fledged form through a Filter lock Io conveyed through it into a flow regulator IB where the supplementary fuel experiences its gasification and through the downstream line part 14.1 of the supplementary fuel supply line 14 the carburetor 20 of a not shown Internal combustion engine is supplied. The carburetor 20 sits on an intake line 22 of the engine.

The supplementary fuel tank 12 is arranged at a suitable location in the motor vehicle and fastened by clamping lugs 24. The supplementary fuel in the form of liquid or gaseous liquefied gas can inside the container 12 under a pressure of over 1500 kPa (approx. 200 p:; L), but also much lower e.g. only 200 - 300 kPa (approx. 30 -! 30 psi).

From one below the liquid level in the supplementary fuel tank 12 located point from fuel is withdrawn in liquid form. Appropriately, this is done by the upstream Linde of the supplementary fuel supply line 14 is submerged to below the liquid fuel level in the container 12 will.

The filling of the container 12 with supplementary fuel can be over a compensation valve 26 made with a relief valve is provided for blowing off gaseous liquefied gas under excess pressure. This is a security measure. The further filling of the container 12 is prevented by a float device 3o, the liquid gas level in the container 12 being prevented by a stand glass 32 is made visible. A shut-off valve 34 regulates the gas supply from the container 12. The various parts 26 to? 4 are by one Cover 36 protected with handles ^ 8.

709832/0688

The Filterehleuse 16 is via an electrical line 4o.l with connected to an ignition switch 4o of the vehicle, so that a flow of fuel through the filter lock 16 is prevented for so long becomes how the ignition switch 4o has not yet been operated. In connection 3 to the filter lock 16, the fuel passes through a part 14.11 of the fuel supply line 14 to the flow regulator 18, the other Position will have to be described later. The flow regulator 18 comprises an expansion valve in which the liquid fuel in the gaseous State passes. This relaxation causes a cooling. To dry the gas it is desirable that the cold of hot water is absorbed in lines 42 and 44 from the cooling system 46 of the motor flows and through a water jacket in the flow regulator 18 is performed.

The flow regulator 18 is provided with a supplementary fuel flow valve equipped, which supplementary fuel over the downstream Line part 14.I of the supplementary fuel supply line 14 feeds into the air stream 21 and via a counter device 48 at a point located in the flow direction upstream of the throttle 5o Carburetor 2o feeds. Liquid fuel reaches the float chamber 2o.l of the carburetor 2o via a line 52.

The flow regulator 18 further includes a lock which the Only allows the supplementary fuel supply valve to function when a predetermined minimum amount of air flows to the engine. That means, that a predetermined minimum negative pressure must prevail in the suction line 22 so that the lock responds and the opening of the Supplementary fuel flow valve in flow regulator 18 releases. The suction pressure for actuating the lock is supplied to the controller via the suction line 22 in the direction of flow below the Throttle 5o connected line 52 acted upon. The specified minimum suction pressure corresponds to a predetermined minimum air volume in the air flow to the engine.

As can now be seen from Figure 2, the supplementary fuel fed into an air duct 19 of the carburetor 2o, namely in one

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in the direction of flow below a choke 54, but above the Air funnel 56 located area, which in turn is located in front of the throttle 50. The line part 14.1 ends with an open end 14.2 of the central zone of the air duct of the carburetor 2o »The opening runs transversely to the direction of flow of the air stream 21 in the air duct 19, whereby this opening 14.2 is partially directed upstream.

The reference number 2o.2 denotes the positive fuel level in the üohwimmerkainmer 2o.l of the carburetor 2o. The liquid fuel occurs A main nozzle 2o.4 enters a channel 2o.3 and then arrives into the air flow in the air funnel neck, through an opening 2o.3> l. To reduce the supply of liquid fuel to the engine, the main nozzle 2o.4 was replaced by a smaller nozzle.

The flow regulator 18 will now be described in detail. It comprises a connection 60 for connection to the part 14.11 of the supply line 14. The fuel occurs at a pressure of approx 250 kPa and passes through a pressure reducing valve 62 to finally to get into a chamber 64, where the pressure is about 3o kPa. Supplementary fuel in the gaseous state passes from the chamber 64 via a supplementary fuel flow valve 66 into a supplementary fuel flow chamber 68 with a connection 70 via which the Connection to the downstream line part 14.1 of the fuel supply line 14 can be established. Through the relaxation of the supplementary fuel from the liquid to the gaseous state a cooling is effected. This cooling effect is due to Heat neutralized by using hot water from the engine cooling system by a jacket 72 (via connections 74 and 76 for Lines 42 and 44) is routed. The gas is dried at the same time.

The function of the pressure reducing valve 62 is controlled by a spring 78 and a membrane 80 or by a combination of springs, whereby the membrane 80 forms the wall of a chamber 84, which via a opening 86 is open to the atmosphere. via an adjusting screw 88 the stiffness of the spring 82 can be regulated.

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"α" ^2mrn

The lock, generally designated by the reference numeral 9o, consists of a spring 92 and a stop 94 with fastening on a membrane 96, which forms a wall of a chamber 98 with a connection loo, from which the connection via the line 52 can be made with the intake pipe 22 of the engine.

In the position shown in Fig.j5, the stop 94 rests on the rear end 66.1 of a lever 66.2 and prevents the opening of the supplementary fuel supply valve 66, which is pretensioned in the closed position under the action of a spring Io2. The spring 92 is compressed by the membrane 96 and the stop 94 is withdrawn from the rear end 66.1 of the lever 66.2 only when there is a predetermined minimum suction pressure, ie negative pressure, corresponding to a predetermined amount of air in the air flow to the motor in the chamber 98. If the pressure in the chamber 68 now drops accordingly due to suction at the opening 14.2, a membrane Io4 connected to the atmosphere on one side via an opening I06 drops and causes the spring Io2 to be compressed and thus the supplementary fuel tank to be opened. Feed valve 66. As a result, supplementary fuel reaches the supplementary fuel feed chamber 68 at a pressure of approx 14.2 can get into the air flow.

The structure of the filter lock 16 will now be described with reference to FIG. The filter lock 16 consists of a body 12o with a connection 122 for connection to the upstream part of the supplementary fuel supply line 14 ^ o and in a chamber 1J52. The chamber 132 is provided with an outlet 1 ^ 4, which can be connected to the part 14.11 of the supplementary fuel supply line 14 located between the filter lock 16 and the flow regulator 18. At the outlet 1 ^ 4, the chamber 132 is through a valve IJ> 6 at the end of a through a

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Spring 14o loaded armature 1 ^ 8 closed. A coil 142 is arranged around one end of the housing and is connected to the ignition switch 4o via the electrical line 4o.l. The valve is shown in the closed position. If a current flows in the coil l42, the armature Ij58 is drawn into a concentric position in this coil 142, so that the spring I4o is compressed and the valve lj? 6 is lifted from its seat, whereby the connection between the chamber lj) 2 and the connection Ijj4 is established and supplementary fuel can flow in liquid form through the part 14.1 of the feed line to the pressure reducing valve 02 in the flow regulator 18.

FIG. 5 shows a modified embodiment in which supplementary fuel is withdrawn from container 12 in gaseous form via a supplementary fuel supply line 15 at a pressure of approximately 250 kPa. The fuel reaches a pressure reducing valve l4o, then to a counter 142 and finally via part I5.I of the supplementary fuel supply line 15 to a supplementary fuel flow regulator 144 whose function is similar to that of the regulator 18, except that this does not involve a relaxation - and a reducing valve and a water jacket. The flow regulator 144 is also equipped with a lock generally designated by the reference numeral 90. Those parts of the controller 144 which correspond to comparable parts of the controller 18 are provided with corresponding reference numbers. The supplementary fuel flow chamber 68 has a port 146 for connection to the lying downstream of the reducing valve and said counting part 15.I of the supplementary fuel supply line 15 * wherein the injection of fuel into the chamber 68 at a pressure of ca j> o kPa. The chamber 98 of the lock 90 is provided with a connection loo in order to establish the connection with the air duct leading to the engine via the line 52 in an area located downstream of the throttle 50 in the direction of flow.

The connection 70 from the supplementary fuel supply chamber 68 is via the downstream portion 15 x 2 of the supplementary fuel supply line I5 led to the carburetor 2o. The supply line ends

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- original

fij> 2 '/ IKWl

with an opening I5.2 similar to the opening 14.2 described with reference to FIG. The ends of the tubes 2o.3 and I5.2 lie on the inside of a nozzle assembly 146, the lower end of which is arranged in the plane of the narrowest part of the air funnel 56. The supplementary fuel supply valve 66 is located in the immediate vicinity of the outlet of the fuel supply line 14.1 or 15.2.

When installing the system, smaller main nozzles 2o.4 take the place of the normally used nozzles. The new nozzles 2o.4 show compared to the normal nozzles have a diameter that is about 1/5 smaller. The will run under normal starting and idling conditions Motor with positive fuel from the float chamber 2o.l. This means, that liquid fuel is used for medium-sized machines with speeds of up to about 900 revolutions per minute. The controls 18 and 144 are adjusted so that the supplementary fuel supply valve 66 only opens at speeds above this value.

The quantity ratio of supplementary fuel to liquid fuel is adjusted by turning the motor at a given throttle position, which makes up about 1/4 of the full load position, for example, runs with the reduced amount of fuel supplied and by then the counters 48 and 142 are set so that in this throttle position the engine is idling at maximum speed. It has been found that in this way sufficient ratios between gaseous and liquid fuel over the full throttle opening range guaranteed.

With the dual fuel supply system, there is none Problems with the engine idling because it is idling always works with the supplied liquid fuel. Is that possible The engine turns off the liquefied petroleum gas, so he can still use the supplied gas reduced amount of liquid fuel until supplementary fuel is replenished. One advantage can be seen in the fact that the driving performance of the vehicle with a full filling of liquid fuel and LPG is greater than with liquid fuel alone. For some vehicles, the increase in mileage is around 3o #, with others over 5o #.

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ΐ. "27Q4171

It was also found that when using an air-fuel mixture, in which both liquefied petroleum gas and gasoline are used, a more complete burnout than when in use from gasoline alone. This knowledge was gained by analyzing the exhaust gases.

Liquefied petroleum gas has a higher octane number, i.e. a higher knock resistance than many of the commercially available petrol. Certain Engines require high octane gasoline, so using a combined gasoline and liquefied petroleum gas can do so Gasoline have a lower octane number than gasoline used alone in such engines, due to the high octane number of the liquefied gas, through which a mixture of low octane Gasoline and LPG results as a fuel suitable for such engines.

Depending on the relative cost of gasoline and liquefied petroleum gas, it can even be achieve cost savings, especially in those cases where the gasoline used is cheaper due to the lower octane number than high-octane gasoline is.

In South Africa and in other countries, liquefied petroleum gas is available in large quantities in stock and cheaper than gasoline. For this reason, the use of liquefied petroleum gas as a supplementary fuel in internal combustion engines is advantageous.

The present invention has the advantage over the known systems that supplementary fuel only when required, that is, when a predetermined minimum speed at which a to open the Supplementary fuel supply valve creates sufficient suction pressure, is added. An enlargement of the valve opening position is only achievable with increasing suction pressure, which in turn of a higher engine speed is dependent. In other words, this means that supplementary fuel is only added when it is the engine needs. As an example of a fuel supply before the The actual requirement is the fuel supply via an accelerator pump or to call the main jet of a carburetor.

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Claims (12)

patent claims; : .1 procedure for the supply of a combustion mixture to an internal combustion engine that runs on liquid hydrocarbon fuel and has a carburetor is characterized by: a reduced supply of liquid hydrocarbon fuel to the engine; the operation of the engine with the supplied reduced amount of liquid fuel, creating a flow of air to the engine is effected; Provisions for the supply of liquefied petroleum gas in gaseous form as Supplementary fuel that is fed into the air flow as a function of a specified minimum air volume will, and Supply of supplementary fuel in the air stream in increasing Amounts corresponding to the increasing amounts of air in the air flow. 2. The method according to claim 1, characterized in that The supply of supplementary fuel to the engine is only possible if there is a negative pressure of set height. J). Method according to Claim 1 or 2, characterized in that the reduction in the amount of liquid fuel supplied is approximately 1/1 to 1/2 in terms of volume. 4. The method according to at least one of claims 1 to J5, characterized in that in a carburetor engine the reduction in the amount of liquid fuel supplied by Reducing the diameter of the main carburetor jet (s) of the engine by about 1/5 is achieved. 709832/0688 ORIGINAL INSPECTED 2704 17t SL 5. The method according to at least one of claims 1 to 4, characterized in that the relative proportions of supplementary and liquid fuel are regulated by while the engine is running with a reduced amount of liquid fuel the throttle is opened to a predetermined extent and then the amount of the supplied to the engine Supplementary fuel is adjusted until the engine with the maximum speed for the respective throttle opening runs. 6. Supplementary fuel delivery system for an internal combustion engine with an air inlet and a throttle arranged in the area of the air inlet to control the The amount of air flowing in the engine, characterized by a Supplementary fuel tank (12) for securing Supplementary fuel in the form of liquefied petroleum gas in the liquid or gaseous state under a pressure that is essential is above atmospheric pressure; a supplementary fuel supply line (14, I5) from the container to the air inlet (22) of the engine; a pressure reducing valve (62, I4o) in the supply line (14, 15) to reduce the pressure of the supplementary fuel in the container (12) to a slightly above that atmospheric pressure value lying in the supply line; a counter (48, 142) for detecting the predetermined throughput of supplementary fuel in the discharge line under a predetermined pressure; and a supplementary fuel supply valve (66) in the supply line (14, l'j), which opens only when a negative pressure of a predetermined level and corresponding to a minimum air volume Lm air flow occurs in the air flow (Pl) to the engine, and the Infeed of increasing amounts of supplements 709832/0688 fuel in the air flow depending on the im Air flow allows increasing amounts of air. 7. Supplementary fuel supply system according to claim 6, characterized characterized in that the supplementary fuel enters the supplementary fuel supply line (14) in liquid form and that e'.ne expansion device (62), a pressure reducing valve (62) and a heating device (72) are provided to compensate for the relaxation cold. 8. Supplementary fuel supply system according to claim 6 or ¹ J, characterized by a lock (90) which prevents the opening of the supplementary fuel flow valve (66) until a predetermined minimum amount of air flows to the engine. 9. Supplementary fuel supply system according to claim 8, characterized characterized in that the lock has a stop (94) comprises, which assumes an operative position in which the opening of the supplementary fuel supply valve (66) prevents is, as well as a suction connection (52) to the air inlet of the engine, to the stop in a rest position, in which opens the supplementary fuel supply valve (66) can be convicted. 10. Supplementary fuel supply system according to claims 6 to 9, characterized in that the feeding of supplementary fuel into the air stream (21) in the direction of flow takes place in front of the throttle (50). 11. Supplementary fuel supply system according to claim 10, characterized in that the feed of supplementary fuel into the air flow via a pipe (14.1, I5.2) 709832/0686 with an opening (14.2, 1 ^ .2) in the central area Air flow (21) takes place, the opening running transversely to the direction of flow of the air flow. 12. Supplementary power to ff -Zufuhrsystem according to claim 11, characterized characterized in that the opening (14.2, 1 ^ .2) in the line in the form of an oblique over the line (14.1, 15-2) away executed cut is provided. IJ). lirgunzungskraf ts i; off feed system according to claims 6 to 12, characterized in that the counter (48, IkP.) is adjustable. 709832/0686