EP3380709A1

EP3380709A1 - Fuel/air system for combustion engines

Info

Publication number: EP3380709A1
Application number: EP16805046.6A
Authority: EP
Inventors: Hermann Golle
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-11-26
Filing date: 2016-11-25
Publication date: 2018-10-03
Also published as: DE102015015518B4; DE102015015518A1; WO2017089581A1

Abstract

The injection methods for diesel and DI Otto engines are currently exclusively based on a purely hydraulic jet atomisation, and in the DI Otto method there are the rudiments of an air-supported pre-chamber. In order to improve the atomisation quality, the system pressures are continuously increased, with the diesel injection occurring at over 2500 bar. This borders on mechanical and physical limits. The new solution consists of the supply of pressurised air or other gaseous substances into an air/gas groove (4), which is arranged in the nozzle body (1) or the apex (3) of the nozzle needle (2) directly at the combustion chamber-side end of the injection nozzle. The breaking up of the fuel molecules is effectively supported by the pressurised air, until it is possible to blow a continuous air flow through the nozzle holes (9). A pump unit formed by a fuel pump (20) and a pressurised air pump (21) is also associated with this solution.

Description

Fuel / air system for internal combustion engines

The invention relates to an injection system in which the fuel is not exclusively by the hydraulic

Jet atomization is processed under high pressure.

Rather, by the supply of compressed air,

further substances, if necessary, reducing the

Particulate emission, e.g. B. also in conjunction with a

Reduction of NOx pollutants can be achieved.

Today's purely hydraulic atomization injection systems for diesel and gasoline engines are currently operated at ever higher system pressures. In the case of the diesel common rail systems (CR), it has arrived at 2700 bar, the Otto direct injection (DI) is working zz. with 350 bar. The fuel atomization by compressed air was the original and a very low-emission method. Until the 1920s, this process dominated the large diesel engines; however, the air compressor was a big additional component. His disappearance by the

Pioneering work by the Vickers, Bosch, MAN and Junkers companies ushered in the era of hydraulic atomization and thus the triumph of the vehicle diesel. In the truck sector, the direct injection soon prevailed, the harder

Diesel combustion was accepted. In the passenger car sector, the air remained a good fuel atomization partner through the pioneering work of Prosper L 'Orange. His

Pre-chamber engine with the pre-chamber, which is tied off from the main combustion chamber, "in which a partial combustion takes place, which takes all the remaining fuel under the overpressure of the

Partial combustion similar to the Einblaseverfahren with the resulting combustion gases in the main combustion chamber

blows in and whirls in ", made possible the high engine speeds required for the passenger car diesel and thus a

lower engine weight. The company Daimler Benz, in possession of the pre-chamber patents, held until the 1960s on the pre-chamber engine for the passenger car diesel because of the softer combustion. Other

"Chamber processes" also rely on the good mixing of fuel and air. In particular, the vortex chamber motor according to the patents Oberhänsli, 1930/31 of the company Vomag AG Plauen / V. initially brought to maturity under the name of Vomag-Oberhänsli for the truck, was later prevalent in most passenger car diesel engines, actually up to that

Time when the Swiss M. Ganser presented his CR injection and thus a new era of the

Diesel engine initiated.

There are already known proposals in which the

hydraulic jet atomization is supported by compressed air.

In DE 35 33 014 "a small amount of compressed air is the

Nachgeblasen injection jet ", said compressed air is taken from the engine cylinder with the interposition of an air reservoir.

In DE 32 41 679 "suction slots" are proposed in the nozzle body transverse to the spray holes. Compressing air from the combustion chamber penetrates into these suction slots and the outgoing fuel jet is intended to mix with the air in the intake slots for improved combustion. In both cases, the improvement effect seems to be low, an air re-blowing and simple transverse slots are not enough.

Furthermore, there are a large number of patent proposals that bring two liquid fuels, usually a pilot fuel and an ignition-deficient main fuel, in the injection nozzle for mixing.

In DE 29 24 128, the injection nozzle has two arranged above the nozzle needle seat partial pressure chambers for both Fuels. Two feed channels in the nozzle body lead the ignition fuel from a low pressure pump and the

Main fuel from a high pressure pump too. On

Check valve in the low pressure range prevents one

Backflow of the ignition fuel.

In DE 37 24 987 a second fuel in the

Pressure line are fed, in the phase in which the high-pressure injection is carried out and the system is under a static pressure. As with the previously mentioned systems, here too is a second fuel pump

required.

In DE 29 22 628 the second medium, mainly water, via a hollow-drilled nozzle needle in the combustion chamber

be introduced. This serves the spring chamber for the

Closing spring of the nozzle needle for receiving the water or the second medium. These media are going through

Low pressure pumps or pressure reservoir fed. DE 195 29 826 describes an injection valve for a CR injection system with a solenoid valve control, wherein the control with compressed air from an exhaust gas turbocharger

is supported.

In DE 198 34 867 two nested nozzle needles are provided, which are to be operated in stages and thus can release two, located at different heights injection holes.

In the gasoline DI methods, air-assisted injection methods are also known, wherein conventional intake manifold injection valves are coupled to an air injector. The fuel is atomized in the air injector to a mixture cloud and this mixture cloud into the combustion chamber

injected. The method is therefore based on a lying outside the combustion chamber antechamber, a

additional air compressor is required. The positive Influence of an atomization aid by the compressed air is clearly recognizable, in tests, the pollutants HC + NOx could be reduced by 30%.

These known proposals, of which a plurality of others exist, affect the essence of the present invention only indirectly. To investigate the beam propagation and incipient combustion, there are a variety of

theoretical and experimental work. The

Mixing of fuel and cylinder air is considered as the core of incipient combustion. These

Mixing directly on the cone of the injection nozzle

initiate, is the object of the invention. It is also the object to provide a combined pressure pump for the supply of multiple media. This object is achieved in that the sealing conical seat of the nozzle needle is seen in the flow direction divided into an upper and a lower seat and in the intermediate groove, the compressed air or more,

predominantly gaseous substances, are supplied. Thus, when lifting the nozzle needle, the fuel first encounters the gaseous substances, so that a first premix effect arises. Furthermore, microfine channels are provided in the upper seat, through which the high pressure supplied

Fuel in minimum amount enters this groove, so that a further premix takes place.

To solve the invention task also includes the creation of a pressure pump in which the cylinders are installed for fuel and compressed air to form a unit and the drive is via a single drive / camshaft. Further embodiments are given in the following embodiment. embodiment

The drawings show:

Fig. 1 The basic embodiment of the invention, shown on a seat hole injector.

Fig. 2 An analogous embodiment with a blind hole injection nozzle.

Fig. 3 shows another embodiment of an altered

Blind hole injector, wherein the supply of gaseous substances is controlled by the stroke of the nozzle needle.

Fig. 4 is a schematic overview of the new

Injection system.

In Fig. 1 is located in a nozzle body 1, the nozzle needle 2 with its cone tip 3 sealingly. It is raised abruptly or finely in the known manner by hydraulic pressure, or a piezo package, or another actuator and thus the ejection

initiated. This is the known state of the art.

According to the invention, the cone tip 3 is not continuous to the nozzle body 1, but through an air / gas groove 4, the cone tip 3 comes in two seats for concern and sealing, an upper seat 5 and a lower seat. 6

The highly pressurized fuel is supplied via the fuel space 7 of the cone tip 3, while the compressed air is introduced via the air channel 8 in the air / gas groove 4. When lifting the nozzle needle 2, the fuel flowing in via the upper seat 5 first impacts on the compressed air in the air / gas groove 4 and under a first mixing of

Fuel and air flows through the melee situation through the open lower seat 6 the spray holes 9 to.

In addition to the air duct 8 10 more, mainly gaseous media of the air / gas groove 4 can be supplied via an additional channel and thus for premixing, to break up the fuel molecules, but also to influence z. B. contribute to the NOx emission.

In order to make mixing even more intensive, the upper seat 5 may have microfine longitudinal grooves 11 through which a minimum amount of fuel enters the air / gas groove 4 even when the seat 5 is closed. The actual sealing edge of the nozzle needle 2 is located at the lower seat 6, including in the direction of the nozzle needle tip can, as especially in

Seat hole nozzles usual, an air gap in the hundredths of a millimeter range be attached. On the channels 8 and 10 check valves 12 are arranged in a conventional manner.

FIG. 2 shows the means according to the invention on a blind-hole nozzle. The injection holes 9 do not start from the apex 3, but from a blind hole 13. The air / gas groove 4 can be made enlarged and has a favorable for the outflow of the fuel / air mixture shape. The rest of the procedure corresponds to the information given in FIG.

In the Fig. 3 is the example of a blind hole die

Air / gas groove 4 placed in the apex 3, so that in the same way an upper seat 5 and a lower seat 6 arise. The nozzle needle 2 has - as a second needle guide - a low-backlash guided in the nozzle body 1 collar 14 with an annular groove 15. This is about transverse and longitudinal holes 16 with the air / gas groove 4 in combination. The compressed air flows from the air channel 8 from the annular groove 15 and further the air / gas groove 4, with the effect of

Premix as soon as the nozzle needle 2 opens and the Fuel flows in the direction of the injection holes 9.

With the position of the air channel 8 to the annular groove 15, the air supply can be controlled during the stroke of the nozzle needle 2, which is usually 0.2 mm - 0.3 mm. The vertical, in the

Blind hole 13 ending longitudinal bore 16 is through a

Plug 17 closable. But this plug 17 may also include a nozzle bore, so that a permanent

Coordinated air flow - even when closed

Nozzle needle 2 - in the blind hole 13 and through the

Spray holes 9 flows. For keeping clean the

Spray holes 9 is a positive effect.

The fuel is supplied from a fuel channel 18 to the lying here below the collar 14

Fuel space 7. At the height of the air / gas groove 4, a

Air accumulator 19 increase the volume of air held. The additional channel 10 for the supply of other media - here in the annular groove 15 - is outside the leaf level, the three channels 8, 10 and 18 are then seen in the circumferential direction in the 120 ° distance. 4, the new injection system is shown in the overview. From the pump unit, consisting of a fuel pump 20 and a compressed air pump 21, go

Pipes to the common rail 22, which consists of two pieces of pipe for fuel and compressed air. From this rail 22 branch off to the individual injectors 23 also two line pieces for fuel and compressed air. Both pipes can also be used as a twin-flow special pipe

be united. The fuel pump 20 is supplied in a known manner by a backing pump, usually a submersible pump A, in the compressed air pump 21 may, for. B. pre-compressed air from a turbocharger B are fed. The

Compressed air pump 21 is connected to the cooling circuit C of the

Internal combustion engine connected, with a cooling effect as well for the fuel pump 20 is quite desirable. The

Drive of the two pumps 20 and 21 via a common drive / camshaft 24. In the overview shown in Fig. 4, the measuring and control devices that belong to each injection system, not shown.

The new injection system is not based in principle on the original air injection of the early diesel engines back. It remains in the hydraulic jet atomization, but it is an effective mixing of fuel and air by the inventive agents on the

Fuel nozzle and a corresponding pressure pump

supported. This premix effect, this improved

Breaking up the fuel molecules can end the ever-higher-driving system pressures, so for the

Diesel injection 1000 bar can be sufficient. The

facilitates the expenses for the mechanical elements of the fuel pump and reduces the required

Driving power. These capacities can benefit the compressed air part. The possibility to feed further, above all gaseous substances up to - in special cases - oxygen, sets new accents also for the

Heavy oil combustion in large diesel engines, the

Gas engines with diesel combustion and the di-gasoline engines in cars.

LIST OF REFERENCE NUMBERS

1 nozzle body

2 nozzle needle

3 cone point

4 air / gas groove

5 upper seat

6 lower seat

7 fuel space

8 air duct

9 spray hole

10 additional channel

11 longitudinal groove

12 check valve

13 blind hole

14 fret

15 ring groove

16 transverse and longitudinal drilling

17 plugs

18 power supply channel

19 air storage

20 fuel pump

21 compressed air pump

22 Rail

23 Inj ector

24 drive / camshaft Considered pamphlets

DE 35 33 014

DE 32 41 679

DE 29 24 128

DE 37 24 987

DE 29 22 682

DE 29 32 325

DE 195 29 826

DE 198 34 867

DE 31 17 796

DE 33 10 049

DE 35 40 780

Claims

Fuel / air injection system for internal combustion engines with an injection nozzle, in which an inwardly opening nozzle needle (2) by fuel pressure, a piezo package or another actuator against the

Increased effect of a compression spring and one or more fuels and air in channels and chambers of a nozzle body (1) are fed to a conical nozzle needle seat, and one or more pumps or accumulators that separated fuels with high and low pressure or air of the injector in the

feed these chambers and after lifting the

Nozzle needle (1) the ejection takes place,

In this case, one in the nozzle body (1) at the level of the apex (3) of the

Nozzle needle (2) arranged air / gas groove (4)

To be sealed conical surface of the nozzle needle seat into an upper seat (5) and a lower seat (6) divided and introduced in addition to the fuel media via an air duct (8) and / or on a

Additional channel (10) of the air / gas groove (4) for a

Flow premix under pressure.

Fuel / air injection system according to claim 1, d a c h e c e n e c i n e that the

Air / gas groove (4) in the apex of the cone (3)

Nozzle needle (2) is arranged and compressed air and other media via transverse and longitudinal bores (16) of the air / gas groove (4) are supplied.

Fuel / air injection system according to claim 1 or 2, since you rchgekennzeichnet that compressed air and other media via a in the nozzle body (1) playfully guided collar (14) and an annular groove (15) in the apex (3) of the nozzle needle (2) and by the altitude of an air duct (8) and / or an additional channel (10 ) to the annular groove (15) of the inflow of the media during the stroke of the nozzle needle (2) is controllable.

Fuel / air injection system according to one of

Claims 1 to 3,

It can be concluded that a vertical longitudinal bore (16) acted upon by compressed air can be closed and / or by one in one

Plug (17) located nozzle bore a tuned air flow continuously through the injection holes (9) flows

Fuel / air injection system according to one of

Claims 1 to 4,

There is no such thing as

Longitudinal grooves (11) in the upper seat (5) of the cone tip (3) are introduced, such that even with the nozzle needle (2) minimal amounts of fuel entering the air / gas groove (4).

Fuel / air injection system according to one of

Claims 1 to 5,

It is not possible to use pressure pumps (20, 21) for multiple media in one unit.

Fuel / air injection system according to one of

Claims 1 to 6,

That is, one of a fuel pump (20) and a

Compressed air pump (21) existing pump unit via a common drive / camshaft (24) are driven Fuel / air injection system according to claim 7, since you rchgekennzeichnet that the

Compressed air pump (21) water cooled, as well as with

pre-compressed air is applied.

Fuel / air injection system according to one of

Claims 1 to 8,

That is, fuel and air are supplied separately from the pumps (20, 21) via a rail (22) to at least one injector (23) having an injection nozzle.

Fuel / air injection system according to one of

Claims 1 to 9,

It is also possible that air enriched with oxygen up to pure oxygen and substances which in particular reduce the NOx emissions are fed into the system via an additional duct (10).

Fuel / air injection system according to one of

Claims 1 to 10,

It is not possible to use the system with DI petrol engines.