DE1526337A1 - Internal combustion engine with direct fuel injection and compression ignition - Google Patents

Description

Internal combustion engine with direct fuel injection and Compression ignition * »ORQ Q

The invention relates to an internal combustion engine with direct Fuel injection and compression ignition where the Combustion chamber center resp. the combustion chamber axis coincides with the cylinder axis or in the vicinity of the cylinder axis is arranged, wherein the combustion chamber is either in the piston or cylinder head and the combustion chamber is formed is that in it in the upper dead position of the piston during the compression stroke almost the total intake of combustion air is located, which was previously imposed by known means, especially during the intake stroke, in a circular movement on the combustion chamber axis (circumferential vortex), in which the injection dia. between the axis of the combustion chamber and the largest opening of the combustion chamber is arranged and the fuel by at least two fuel jets of different lengths, which when View in the direction of the cylinder axis - essentially running across the circumferential vortex and not the edge of the combustion chamber opening Over injection, is injected into the combustion chamber, whereby a Part of the fuel hits the combustion chamber wall and part of the injected fuel immediately hits the combustion air is distributed.

In known engines, in which the fuel jets are transverse to the Uafangswirbel when looking in the direction of the cylinder axis, the intersection of the injection hole axes and DUsenlangsacb.ee, hereinafter referred to as the center of the injection sphere, is arranged as close as possible to the axis of the combustion chamber or the direction of the fuel jets is selected so that all fuel jets have the same free jet length as far as possible and are therefore subject to the same mixture formation factors as possible. The disadvantage is that a result of the same Geaischbiidungsf aktorer i r, stVis force • fcoffstrahlen · several "Kund Lesions _t voaurci '.'; the # combustion under high 5 «smoke development is taking place»

00881S / 0603

BATH ORIGINAL

There is also an increase in the speed of the circumferential vortex the combustion air to an optimum is not possible because the fuel jets are blown into one another or at least the combustion noise cannot be optimally designed.

Furthermore, a method with a circumferential vortex and a spray direction of the fuel jets running transversely thereto is known, in which the spray ball center of the injection nozzle is intentionally arranged outside the axis of the combustion chamber «. To thereby reach different fieiss lengths represent fuel jets are in Varbindeng with different high Strahlaaftreffstelleffi on Brann room wall sur localization of ZUndortes lead · Is based on the idea ₉ that the ignition of Iraftstoffstr & lil 'it the shortest freisa length starts when Diás fuel jet is towards SJrsnnrauin -Sffn'Jißgskante is directed, with in particular a toilet of the force-.5ofies of the jacket of this fuel jet -33 aer Qu9tsöÄ8tröaisag sprayed against what sehnellai ¹ evaporation ^; xnü ÖV & lichfir GealgcfesttP®iaherung leads »All vu ^ igen fuel jets show less favorable in this regard? Conditions on _s "7-S & 3. They are deeper in the combustion chamber auitreffoE © Äasserdea is due to the syringe iit dia Quetsehst ^ ömung © Ie Purser 3üadveraag aagsstf®bt« ad vsr effective © Especially äls-jc ·? Kursa 5ündysi'Süg abe? Wlf ^ sttsiiäc for ii® Steigor-iiag cia.3 üsfaags-

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^ß AD ORIGINAL

The purpose of the invention is to make the economy known to improve direct injection combustion processes, to enable a higher mean effective pressure, to reduce the opacity of the exhaust gas and to lower the combustion noise.

The object of the invention is to achieve a combustion method which increases the volume vortex of the combustion air allows for an optimum in which the initial ignition is always based on only one fuel component one and the same fuel jet takes place, while all other fuel jets are designed and directed so that favorable ^ genetic formation conditions for something that is as homogeneous as possible The fuel-air mixture is given and a long ignition delay is achieved with the shortest possible heating law.

According to the invention, this "object is achieved in that a Fuel jet designed as the longest jet (ZUndstrahl) and is so directed that "in part of the Hanteis this longest The hottest or indirectly adjacent zone of the Brennrauaes touches, while all other fuel jets are directed in such a way that they are about the same height as the longest fuel jet on that combustion chamber - on the combustion chamber. wall, in which the spray ball center of the injection nozzle is located, whereby the combustion chamber is bisected by a plane perpendicular to the plane of the center of the spray ball and the combustion chamber axis is made through the axis of the combustion chamber. In one embodiment of the invention, when looking in the direction of the cylinder axis, the injection hole axis is the longest fuel jet placed almost or directly in the plane that runs between the axis of the combustion chamber and the center of the spray ball of the injection nozzle.

In a further embodiment of the invention, the injection hole axes of the fuel jets when looking in the direction of the cylinder axis with an arrangement of more than two fuel jets are symmetrical with respect to the plane of the injection ball center point-combustion chamber axis and the injection ball center point of the injection nozzle is at least 20 to 25 % of the largest combustion chamber diameter away from the combustion chamber axis .

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BATH ORIGINAL

The combustion noise of the combustion system according to the invention is low because the initial ignition is always in the longest Fuel jet takes place and because of the homogeneous mixture, especially a micro-mix, the rate of reaction is diminished; because it is not the amount of fuel injected but the amount of fuel that is important.

The embodiment according to the invention has the following conditions for an economical fuel combustion with optimal circumferential vortex of the combustion air calculation:

a) The ZUndverzug is relatively long, so not a liquid one Fuel is sprayed through the flame.

b) The fuel reaching the combustion chamber wall forms thin, short films seen in the plane of the circumferential vortex, thus is the risk of soot formation and a high reaction rate due to an excessively rich mixture Filiiende avoided and at the same time the evaporation rate small amount·

c) The fuel reaching the combustion chamber wall forms a large file area through the multi-jet nozzle, so that the fuel after ignition under the influence of the convective Heat transfer and the radiant heat evaporate quickly and a short stimulus law is created.

d) The fuel jets spray largely perpendicular to « Circumferential vortex.

To achieve a short heating law and security sharing of cold start · is · determined · in · fuel quantity · by the circumferential vortex blown out of the fuel jets.

e) The number of injection holes is greater than one, because for a given Overall spray hole cross-section, the homogeneity of the spray structure increases with an increasing number of spray holes, which on the one hand means an extension of the Zlindverzuges and on the other hand an improved cold start ability.

009819/0603

^ß AD ORIGINAL

f) A fuel jet has a greater free jet length on than the remaining fuel jets. He is so directed that he always provides the initial spark.

g) The sector angle between two adjacent fuel jets is according to the free jet length (jet resolution), the circumferential vortex speed and the direction of flow matched between the circumferential vortex and the direction of the fuel jets, thus under the influence of the circumferential vortex no impermissible disturbance of the mixture formation of the downstream jets by the upstream jets located entrance.

h) Depending on the spray direction, free jet length and shape of the combustion chamber have the jet impact points (thought of as Penetration point of the spray hole axis through the combustion chamber wall) at least almost the same height distances to the piston crown and are so deep in general the combustion chamber that no fuel from the jet jacket into the gap between the piston and cylinder head. is injected onto the piston crown "

i) In order to achieve optimal conditions for the thermal mixing of the To obtain the amount of fuel distributed across the wall, the film · in the vicinity of the maximum combustion chamber diameter on the combustion chamber wall arranged.

Because only «in fuel jet« la «larger · free« jet length · has fuel jets than the remainder, it is a Combustion system possible, especially “through coordinated jet direction and free“ jet length ”su“ iner high to get the optimal Uafangswirbeldrehzahl, and on the other hand The presence of a fuel jet with a large free jet length guarantees a good cold start and the localization of the initial ignition in this longest beam. After ignition, the flame spreads in the Combustion chamber off, with the amount of fuel injected in a distributed manner and the evaporated or evaporating from the combustion chamber wall Amount of fuel after mixing with the combustion air Y «r'orenat ·

009819/0603 _oiriNAL

BATH ORIGINAL

Desired favorable heating law form and short heating duration, caused by localized initial spark, homogeneous distribution of the air-distributed fuel to the combustion air, avoidance of high fuel concentrations de3 of the combustion chamber wall evaporating fuel in the combustion air at the end of the film, large film area and coordinated peripheral vortex speed allow a relatively late start of combustion to be achieved in terms of economy, whereby the engine runs smoothly at the same time «

The combustion system according to the invention has due to the eccentrically with respect to the combustion chamber axis arranged spray ball center furthermore the advantage of a large constructive Freedom both for the valve arrangement with two valves per cylinder and for the design of the inlet and outlet channels and, due to the central position of the combustion chamber, results in uniform piston temperature, especially in the vicinity of the piston ring grooves.

The invention will be explained below using examples will. In the accompanying drawings seig «at

Fig. 1t «la syst · * alt 3 asymmetrical concerns the level of the fuel sphere center point-Brennrauaacbs · arranged fuel jets,

Fig. 2 χ the section A-A of Fig. 1

Fig. 3t a system with 2 fuel jets, which in the Ibcn Spritskugelmittelpunkt-Breanriaa & chs · are arranged,

Fig "4" a system old 3 eymmetrical concerning "the Sben" Spritskttgelmittelpuakt-Brennraumaehsff Jetting arranged fuel

The cylinder axis 1 coincides with the combustion chamber axis 2. The injection nozzle and therefore the center of the spray sphere are located at a certain distance from this. The fuel jets h \ 5; 6 symbolized by the direction of the spray hole axes, meet at the fuel impact points 1o; 11; 12 on the combustion chamber wall so that the film 13; 14; Form 15 on the combustion chamber wall.

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BATH

In reality the beam axes have due to the circumferential vortex 9 roughly the dash-dotted course, d. H. both the impact points and the filae are in the direction of flow of the circumference vortex shifted. From the dumbbell of the longest fuel jet 4 is due to the large free jet length the blowing of the fuel is strongest · So that it does not affect the downstream fuel jet 6 unfavorably influenced, is the distance on the combustion chamber circumference between the fuel jet impact points 1o; 12 greater than between the positions 11; 12 resp. 1o; 11. The distance between the fuel jet impact points 1oj 11 may be smaller because the fuel jet 5 has a shorter jet length. this also applies to the fuel jet 6. Because the circumferential vortex 9 but the fuel jet 6 practically on the combustion chamber wall blows while the fuel jet 5 through the circumferential vortex 9 is practically pushed away from the combustion chamber wall, the distance between the fuel jet impact points must be and 11 will generally be larger than between impact points ii; 12.

Fig. 2 shows that the fuel jet impact points 1o; 11; above the largest combustion chamber diameter 8 _f, ie in the direction of the opening edge 7 of the combustion chamber, so that the centroids of the film 13; 14; 15 lie at least approximately on the largest combustion chamber diameter 8.

Fig. 3 shows a system in which because of the low number of beams the optimal Urafangswirbelspezahl is high and at which the as to the fuel jet impact point 1o downstream lying · sector in particular g «(« n Bnd · of the fuel injection is charged with air from the other sector, which is relatively little penetrated by fuel, whereby the matter the fuel jet impact point 1o downstream, from the fuel jet 4 originating mixture is practically emaciated, so that the left-distributed fuel below less Rußbilduhg burns.

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BATH

The fuel jet impact point 1o upstream Keeping the lying sector relatively free of airborne fuel EU is possible thanks to the short free jet length of the Fuel jet 5.

Fig. 4 shows a system that has almost the same high optimal Uafangswirbeid speed allows as shown in Fig. 3 system, because of the fuel jet impact point 1o downstream Until the next fuel jet impact point, the existing distance on the circumference of the combustion chamber has only changed slightly is. The sector between d * n impact points 1o; 11 is interspersed with little air-dispersed fuel here too, veil the free «jet length of the fuel jet 5 is small. The fuel jet 6 also has a short free jet length, whereby dl penetration force of the fuel jet 6 is great. Because it is also due to the small free jet length If it is not dissolved much, a lot of fuel reaches the combustion chamber wall over a short period of time, so that the fuel jet is wiped in the sector tr «ff set 11 {12 no« unacceptable · Mixture over-greasing as regards the air-distributed fuel from the fuel jet 6 is present.

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Claims (4)

Claim * 1. Combustion engine with direct fuel injection and compression ignition, in which the center of the combustion chamber, respectively. the axis of the combustion chamber coincides with the cylinder axis or is arranged in the vicinity of the cylinder axis, the rotationally symmetrical combustion chamber with a connection opening constricted towards the cylinder surface being either in the piston or cylinder head and the combustion chamber being designed in such a way that it is located in the cylinder head The top dead center of the piston during the compression stroke is almost all of the intake combustion air, which was previously imposed by known means, especially during the intake stroke, in a circular movement around the combustion chamber axis (circumferential vortex), in which the injection nozzle is between the combustion chamber axis and the largest diameter of the combustion chamber to the cylinder or combustion chamber axis is arranged in an inclined manner and the fuel is injected into the combustion chamber through at least «« white fuel jets of different length, which when looking in the direction of the cylinder axis run essentially transversely to the circumferential vortex and do not overlap the edge of the combustion chamber opening, whereby • in part of the fuel hits the combustion chamber wall and part of the injected fuel is immediately distributed to the combustion air, characterized in that a fuel jet (A-) is designed as the longest jet (INJECT jet) in that tr on d « The area of the fuel wall (8) is directed farthest away from the injection ball center of the injection nozzle (3) - that is, from the intersection of the injection hole after the injection nozzle with the nozzle longitudinal axis - and part of this fuel jet is the hottest · Or directly in front of it * »Adjacent zone around the combustion chamber, etc. Cylinder axis (1 {2) touches, while all «other fuel jets (5; 6) are directed so that they hit the combustion chamber wall (8) at about the same height as the longest fuel jet (4) in that combustion chamber belly side The center point of the injection ball is located, the combustion chamber being bisected by a combustion chamber axis (2) placed perpendicular to the center point (3) of the combustion chamber axis (2) through the combustion chamber axis (2). 009819/0603 New documents 1 ** 71 ^. ™ ^ 2. Internal combustion engine according to claim 1, characterized in that when looking in the direction of the cylinder axis, the spray hole axes of the fuel jets are asymmetrical to the plane between the axis of the combustion chamber and the center of the spray sphere the injector runs. 3. Internal combustion engine according to claim 1, characterized in that the use of only two fuel jets Injection hole axes of the ointments in the plane "injection ball center point-firing space axis" lie, 4. Combustion engine aaeh claim 1 _t characterized »that when» view ia direction Zyliaderachse in an arrangement with more than two fuel jets whose Spritzloehachsan symmetrically with respect to the plane · "Spritzkugelmittelpunki-Brenfiraismachse ¹¹ and Spritzkugilmittelpunkt the injection nozzle by at least so up to 25% of the largest The combustion chamber diameter is removed from the combustion axis. 009819/0603