AT520741B1 - Internal combustion engine - Google Patents

Abstract

The invention relates to an internal combustion engine (20) with a gas distributor (1), in particular an EGR gas distributor, wherein the gas distributor (1) has at least one distributor chamber (5) provided with at least one charge gas supply line (3) for feeding charge gas into the distributor space (5) and at least two discharge channels (4) for discharging the charging gas from the distributor chamber (5) is connected, the distributor chamber (5) via a distributor opening (12) with the immediately adjacent to the distributor opening (12) discharge channels (4) is fluidly connected and wherein the distributor opening (12) is subdivided into a number of regions (13) corresponding to the number of subsequent discharge channels (4) and the total cross-sectional area of the distributor opening (12) is divided equally over the regions (13), each discharge channel (12) 4) an area is assigned. The object of the invention is to provide a gas distributor, which allows the best possible adjustable division of the charging gas to the discharge channels, without having to have a large flow resistance. This is achieved by arranging at least one deflection element (15) between the charging gas supply line (3) and the distributor opening (12).

Description

Description: The invention relates to an internal combustion engine with a gas distributor, in particular an EGR gas distributor (exhaust gas recirculation gas distributor), the gas distributor having at least one distributor space which has at least one charge gas supply line for supplying charge gas into the distribution space and at least two discharge channels for discharge of the charge gas from the distribution space is connected, the distribution space is connected in terms of flow via a distribution opening to the discharge channels directly adjoining the distribution opening, and the distribution opening is divided into a number of areas corresponding to the number of subsequent discharge channels and the total cross-sectional area of the distribution opening is divided equally into that Areas are divided, an area being assigned to each discharge channel.

It is a known measure, a part of the exhaust gases of an internal combustion engine via an exhaust gas recirculation line (EGR line, or "EGR" for "Exhaust Gas Recirculation") to the inlet, in particular to the intake manifold. This is an attempt to reduce undesired engine emissions (especially nitrogen oxides in diesel engines) and fuel consumption (especially in Otto engines in the partial load range) under certain driving conditions.

To prevent EGR devices from negatively influencing engine performance, including fuel efficiency and power output, the recirculated exhaust gas is mixed appropriately with intake air and the EGR / air mixture is distributed as evenly as possible to each cylinder of the internal combustion engine. For this, it is necessary to provide a suitable EGR distribution that can be easily and cost-effectively integrated into an existing engine structure.

For this purpose, US 2015/0020781 A1 describes gas mixers which also act as distributors, guide plates being provided which distribute the charging gas via discharge ducts. However, the division of the charge gas cannot be optimally selected over all discharge channels, since in particular the channels further away from the inlet are supplied with smaller amounts of gas. As a rule, an even distribution is desired.

[0005] KR 10 2007 0046570 A1 describes a gas distributor for uniformly distributing charge gas for an internal combustion engine, a perforated plate designed as a barrier with holes of different sizes being arranged in a distributor space. As a result, the inflowing charge gas is divided in a defined way, via discharge ducts below. However, it is disadvantageous that this design leads to a very large gas resistance for the charging gas.

AT 002 434 U1 describes a distribution of the charge gas via a distributor node. This embodiment has a lower flow resistance, but it is disadvantageous that despite the flow calming of the charging gas in the distributor node, the discharge channels are supplied in very different ways.

Is described a distributor space with a distributor opening, which has segments corresponding to the number of discharge channels, each of which is connected to a discharge channel. This has the advantage that the gas that is guided is distributed more evenly among the discharge channels. However, a particularly strong pulsation of the gas inlet can still lead to an uneven distribution.

The object of the invention is to provide an internal combustion engine with a gas distributor, which enables the most uniform possible distribution of the charge gas to the discharge channels, without having too great a flow resistance.

This object is achieved in that at least one deflection element is arranged between the charge gas supply line and the distributor opening.

[0010] The equal division of the total cross-sectional area over the regions ensures that 1/15

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Patent office provided that no discharge duct is supplied with more charging gas than another. At the same time, such an embodiment can be easily produced, since, for example, the distributor opening is created first and is subsequently divided into regions. This division can take place, for example, through walls which divide the distributor opening into the areas and delimit them from one another. The distributor opening can be circular, but can also have any other shape. The arrangement in the distribution space is particularly advantageous since the charge gas can mix in the distribution space or can calm down. This ensures an even distribution and reduces the dependence on pulsation.

In a preferred embodiment, the distributor opening is designed as a distributor star. A distribution star is understood to mean an arrangement which has a plurality of discharge openings which are delimited from one another by straight walls which are essentially arranged radially around a center point. This represents a particularly compact and simple arrangement, it being possible for the symmetrical arrangement of the walls to be adjusted so that the discharge channels are supplied uniformly. In the case of two discharge channels, it is also possible to provide only one wall which divides the distributor opening into two regions of the same size, preferably designed as semicircles. Alternatively, it can also be provided that the wall or the walls are arranged concentrically in the distributor opening and so the areas are delimited from the inside to the outside.

In this sense, a discharge channel is understood to be a flow path for the discharge gas, which discharges part of the exhaust gas from the gas distributor in the direction of a combustion chamber. This can be designed differently, for example as a pipe, as a cast channel or as a line.

In a preferred embodiment it is provided that the distribution space has at least one lateral surface and at least one base area, the charge gas supply line opening into the distribution space via a supply opening arranged in the lateral surface and the distribution opening being arranged in the base area of the distribution space. The lateral surface is arranged at the edge of the base area and surrounds it. In this case, for example, a second base surface, preferably opposite the first base surface, can also be provided and the lateral surface connect these to one another. Alternatively, the lateral surface can also converge pointedly or bluntly, as a result of which only one base surface is required. The arrangement of the distributor opening on a base surface ensures that the discharge channels are supplied evenly. Such an embodiment can also avoid the pulsation dependence of the supply of the discharge channels.

It is particularly advantageous if three discharge channels are connected to the distributor space via the distributor opening. In this case, radially arranged walls which delimit the regions from one another can be at an angle of 120 ° to one another.

[0015] It can further be provided that the distribution space has a substantially point-symmetrical shape in normal planes of a central axis and / or has a shape that is essentially rotationally symmetrical about the central axis. In this case, each point of the lateral surface of the distributor space is preferably point-symmetrical in the normal plane, particularly preferably rotationally symmetrical, with respect to a central axis of the distributor chamber. This symmetrical shape allows the charge gas to mix particularly well and the transmission of pulsations can be further prevented.

It is advantageous if the distribution space has at least an essentially pot-like or bowl-like shape with a lateral surface and at least one base surface. Due to a pot-like or bowl-like shape of the distribution space, the incoming charge gas is first distributed in the space before it is led into the discharge channels. This also leads to circulation currents and thus a uniform distribution of the charge gas in the distribution room.

The lateral surface of the distribution space preferably has a cylindrical shape, whereby cylindrical shapes are also meant not only with circular, but also with elliptical or oval base areas. The lateral surface can also be turned,

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Patent office, for example, a circular cylinder, cone or torus can be formed. The distribution space can also have projections or depressions.

It is also particularly advantageous if the distributor opening has discharge openings leading to the discharge channels, which are arranged in a rotationally symmetrical manner about the central axis. For example, discharge openings of the discharge channels can be designed as circular segments. Alternatively, bores can also be arranged in a rotationally symmetrical manner in the base area. The central axis is understood to mean an axis which, in embodiments with only one base area, runs through its center and extends essentially normal to the base area of the distributor space, or in embodiments with two base areas runs through the center points of both base areas.

[0019] It can be provided that a center point of the distributor opening lies on a central axis of the distributor space. This is particularly useful if the distribution space has one of the symmetries along the central axis already described.

It is advantageous if the charge gas supply line is arranged on the lateral surface of the distributor space in such a way that the charge gas can flow into the distributor space in a direction that is essentially normal to a central axis of the distributor space, preferably in a radial direction. It can also be provided that the charge gas feed line is arranged on the lateral surface such that the charge gas supplied flows eccentrically to the central axis into the distributor space. This improves the flow in the distribution space and a, for example circulating, main flow direction can be specified in the distribution space or the formation of a particularly strong main flow can be deliberately prevented with a suitable arrangement.

Furthermore, it can be provided that at least one charge gas supply line connected to the distribution space via at least one supply opening is arranged substantially normal to a central axis of the distribution space. This further improves the distribution of the charge gas in the distribution room.

It is also advantageous if the charge gas supply line is arranged radially on the lateral surface of the distributor space. This leads to a more homogeneous mixing and distribution of the charge gas in the distribution room. Alternatively, however, it can also be provided that the charge gas supply line is tangential to the lateral surface of the distributor space. As a result, the charge gas can be swirled irregularly in the distribution room.

It can also be advantageous if the charge gas supply line widens in the area of the supply opening or increases its cross section. This allows the flow to settle before the charge gas enters the distribution space.

It is particularly advantageous that at least one deflecting element is arranged between the charge gas feed line and the distributor opening, preferably in the distributor space between a feed opening of the charge gas feed line and the distributor opening, particularly preferably projecting from a base area of the distributor space. The deflecting element can lead to a deflection or swirling of the charge gas flows and thereby prevent unfavorable flows which shift the supply conditions between the discharge channels.

The deflection element can for example be arranged in the charge gas feed line. It can also be provided that the deflection element is arranged in the distribution space. This results in turbulence and mixing, especially in the distribution room.

In order to achieve an even better effect with a compactly designed deflection element, it can be provided that the deflection element is arranged on that base surface of the distributor space on which the distributor opening is arranged.

To prevent undesired direct flows from the feed opening to the distributor opening, the deflection element can be arranged between the feed opening and the distributor opening.

If it is provided that the deflecting element has at least one guide surface with

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AT 520 741 B1 2019-07-15 Austrian patent office, the charge gas flowing into the distribution space can be deflected in one direction along a lateral surface of the distribution space, the guide surface preferably being convex to a main flow direction of the charge gas flowing into the distribution space through the charge gas supply line, so so that an effective diversion of the charge gas can be achieved with low flow resistance. These directions along the lateral surface mean that the flow moves following the extension of the lateral surface. In the case of a cylindrical outer surface, these are, for example, circular flows. It is not essential that the entire inflowing charge gas is deflected, only a part of it can be deflected or only a part of the deflected charge gas can be deflected in the direction along a lateral surface.

It is particularly advantageous if the deflecting element has a height that is between 30% and 70%, preferably 50% of a distributor height of the distributor space, and / or that the deflecting element has a width that is between 75% and 120%, preferably 100% of a feed line width of the feed opening is. Sufficient swirling or redirection is thus achieved by the deflecting element. The term width is understood to mean the clear width between two opposite edges of the deflecting element and the distributor height means the clear height along the central axis. The deflecting element can be listed as a wall-like element with essentially constant height and width. However, it can also have different heights along its width or different widths along its height. However, the deflection element can also have any other, possibly multi-part shape, for example a ramp shape or a lattice shape. Openings in the deflecting element are also possible.

The gas distributor can be used to divide exhaust gas used only for recirculation over several discharge channels. For this purpose, it is advantageous if the charge gas is recirculated exhaust gas from the internal combustion engine. The parts of the exhaust gas can be mixed with fresh air after their division.

[0031] However, the gas distributor can also be used to split an already mixed charging gas. Accordingly, the charge gas can also be a mixture of exhaust gas and fresh air.

It can also be provided that at least one discharge channel opens into an intake line leading to a cylinder of the internal combustion engine, preferably each discharge channel opening into exactly one intake line leading to a cylinder of the internal combustion engine.

The present invention is explained in more detail below on the basis of the non-restrictive embodiment variant according to the invention shown in the figures. Show it:

Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 show an embodiment of a gas distributor 1 according to the invention on one Fresh air distributor in a perspective view; the gas distributor 1 in a side view; the gas distributor 1 in a plan view;

the gas distributor 1 in a section along a line IV-IV in Fig. 2;

the gas distributor 1 in a section along a line V-V in Fig. 2;

the gas distributor 1 in a section along a line VI-VI in Fig. 3;

a part of the gas routing containing the gas distributor 1 of an internal combustion engine 20 according to the invention in a schematic representation.

The embodiment of a gas distributor 1 shown in the figures is arranged on a fresh air distributor 2 (FIGS. 1, 2, 3). The fresh air distributor 2 is composed of two jacket parts. The gas distributor 1 has a charge gas supply line 3 in the form of a pipe section, three discharge channels 4 in the form of flat channels and a cylinder 14/15 arranged in between

AT 520 741 B1 2019-07-15 Austrian

Patent office look at distribution room 5. A distributor opening 12 arranged on a base surface 10 of the distributor chamber 5, parts of the charge gas supply line 3, the distributor chamber 5 and the discharge channels 4 are designed in one piece as a common housing part. The discharge ducts 4 are partly delimited by this common housing part and partly by the jacket of the fresh air distributor 2 on the side facing the fresh air distributor 2. This reduces the amount of jacket material used and represents a space-saving design suitable for production. Alternatively, the fresh air distributor 2 and the discharge channels 4 can also be designed as independent components. The arrangement of the discharge ducts 4 should preferably be such that the line lengths of said ducts have the same length or the same flow resistance as well as possible. This supports the corresponding equal distribution.

The discharge channels 4 are partially delimited in the downstream area by additional jacket parts 6, 6a. At the downstream end of each discharge channel 4 there is a mixing opening 7, which opens into an intake line 8 of an internal combustion engine 20, not shown. The three intake lines 8 are supplied with the charge gas transported through the mixing openings 7 and also with fresh air through the fresh air distributor 2. The discharge channels 4 run along the surfaces of the fresh air distributor 2 and the respective intake line 8.

The charging gas supply line 3 has at its upstream end a connecting member 3a for connection to an exhaust gas-carrying line or a charging gas-carrying pipe which supplies the gas distributor 1 with charging gas. In the illustrated embodiment, this is compressed and cooled exhaust gas. The charge gas feed line 3 has an initially round cross section in the area of the connecting member 3 a, which then flattens and widens somewhat further downstream. It increases its cross-section in the area of the feed opening 9 and assumes an essentially square shape with rounded edges. It ends in a feed opening 9 which leads into the distribution space 5. The charge gas is thus directed from the connecting member 3a to the feed opening 9 and thus defines a main flow direction 16 of the charge gas. A part of the charge gas supply line 3 and the distribution space 5 is formed by a cover part 11, which has a flange for sealing at its edges.

The charge gas supply line 3 opens into the distribution space 5 essentially radially with respect to a central axis 5a. In the exemplary embodiment shown, a longitudinal center plane E of the charge gas supply line 3 is spaced apart from the central axis 5a by an eccentricity e.

The distribution space 5 in the exemplary embodiment has a substantially cylindrical shape, only the base surface 10 facing the fresh air distributor 2 has an outer ring which tapers inwards and outwards (FIG. 6). In addition, the distributor space 5 has a flat further base surface 28 opposite the base surface 10 and a lateral surface 17 connecting the base surfaces 10, 28. The lateral surface 17 is point-symmetrical in the normal planes of the central axis 5a. In addition, it is even rotationally symmetrical along the central axis 5a, which extend through the central points of the base surfaces 10, 28 and extends normal to them. It thus has an essentially pot-shaped or bowl-shaped shape, which first widens conically along its height over a short section and then has a constant diameter. The supply opening 9, which has an essentially rectangular shape, is arranged in the center of the lateral surface 17 of the cylinder.

In the center of the base 10 facing the fresh air distributor 2, the distributor opening 12 is arranged, which is designed as a distributor star (FIGS. 4, 5). In an alternative embodiment, a further distributor opening can also be provided on the opposite further base area 28. The distributor opening 12 of the base area 10 has three areas 13 in the form of openings, which in the example are designed as equally large and equally shaped, 120 ° covering circular segments, being rotationally symmetrical about a center point R of the distributor opening lying on the central axis 5a of the distributor space 5 12 are arranged. They are delimited on the sides facing one another by star walls 14. In order to

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The patent office describes the areas 13 together the substantially circular distributor opening 12, which is divided by the star walls 14. The center R lies in the center plane 5a and also represents the center of the base area 10. Such an embodiment can be produced, for example, by first drilling this circular distributor opening 12 and subsequently arranging the star walls 14. Alternatively, the star walls 14 can be produced together with the surrounding parts of the distribution space 5. Each of the areas 13 as an opening leads to a discharge channel 4 arranged between the distribution space 5 and fresh air distributor 2.

Between the distributor opening 12 and the feed opening 9, a deflection element 15 is arranged on the base 10 facing the fresh air distributor 2, which is designed as a wall (FIG. 4). It has a guide surface 31 facing the inlet opening 9, which is curved along its width and is convex with respect to the main flow direction 16 and thus concave with respect to the distributor opening 12. The curvature describes a segment of a circle around the center R, with which the deflecting element 15 is concentric with the circular opening. It thus directs charging gas flowing in from the inlet opening 9 in several directions, including directions 30 along the lateral surface 17. In addition, there is a deflection via the deflection element 15 in the direction of the further base surface 28.

The deflection element 15 has a width extension 15b, which makes up 75% of a feed line width 9b of the feed opening 9. The deflection element 15 also has a height extension 15h, which makes up approximately 40% of a distributor height 5h of the distributor space 5. The charge gas introduced mainly in the main flow direction 16 is thus diverted and swirled by the deflection element 15 in the distributor space 5 in other directions. This creates a flow in the distribution space 5, which enables a substantially uniform distribution of the charge gas in the distribution space 5.

7 shows part of an embodiment for a gas duct of an internal combustion engine 20, in which the gas distributor 1 according to the invention can be used. The exhaust gas of an internal combustion engine 20 with three cylinders is collected from the combustion chambers via an exhaust manifold 23, partially discharged via an exhaust gas aftertreatment system 21 and partially recirculated. The recirculation takes place via a precooler 22, an EGR valve 24 for setting the amount of exhaust gas recirculated and a further high-pressure EGR cooler 25 until the recirculated exhaust gas is fed into the gas distributor 1 as charging gas. The non-recirculated exhaust gas also drives a turbocharger 26, which compresses fresh air drawn in. This compressed fresh air is also cooled via a fresh air cooler 27 and passed into the fresh air distributor 2, which also divides the fresh air into three parts. Each of the three parts of the exhaust gas divided by the gas distributor 1 is mixed with a part of the divided fresh air, as shown in the other figures, and passed into a cylinder.

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Patent Office

Claims (10)

claims 1. Internal combustion engine (20) with a gas distributor (1), in particular an EGR gas distributor, the gas distributor (1) having at least one distributor space (5), which has at least one charge gas feed line (3) for supplying charge gas into the distributor space (5) and at least two discharge ducts (4) for discharging the charge gas from the distribution space (5) are connected, the distribution space (5) is flow-connected via a distributor opening (12) to the discharge ducts (4) directly adjoining the distributor opening (12), and the distributor opening (12) is divided into a number of areas (13) corresponding to the number of subsequent discharge channels (4) and the total cross-sectional area of the distributor opening (12) is divided equally between the areas (13), with each discharge channel (4) having an area is assigned, characterized in that at least one deflection element (15) is arranged between the charge gas supply line (3) and the distributor opening (12). 2. Internal combustion engine (20) according to claim 1, characterized in that the distribution space (5) has at least one outer surface (17) and at least one base surface (10), the charge gas feed line (3) via a feed opening arranged in the outer surface (17) (9) opens into the distribution space (5) and the distribution opening (12) is arranged in the base area (10) of the distribution space (5). 3. Gas distributor (1) according to claim 1 or 2, characterized in that the distributor space (5) has a substantially point-symmetrical shape in normal planes of a central axis (5a) and / or has a substantially rotationally symmetrical shape around the central axis (5a). 4. Internal combustion engine (20) according to any one of claims 1 to 3, characterized in that a center point (R) of the distributor opening lies on a central axis (5a) of the distributor chamber (5). 5. Internal combustion engine (20) according to one of claims 1 to 4, characterized in that the charge gas supply line (3) is arranged on the lateral surface (15) of the distributor space (5) that the charge gas in a substantially normal to a central axis of the Distribution space (5) extending direction, preferably in the radial direction in the distribution space (5) can be flowed. 6. Internal combustion engine (20) according to one of claims 1 to 5, characterized in that the at least one deflection element (15) in the distributor space (5) between a feed opening (9) of the charge gas feed line (3) and the distributor opening (12), preferably projecting from a base area (10) of the distributor space (5). 7. Internal combustion engine (20) according to claim 6, characterized in that the deflecting element (15) has at least one guide surface (31) with which in the distributor space (5) flowing charging gas in one direction (30) along a lateral surface (17) of the The distributor space (5) can be deflected, the guide surface (31) preferably being convex to a main flow direction (16) of the charge gas flowing into the distributor space (5) through the charge gas supply line (3). 8. Internal combustion engine (20) according to claim 6 or 7, characterized in that the deflecting element (15) has a height extension (15h) which is between 30% and 70%, preferably 50% of a distributor height (5h) of the distributor space (5) , and / or that the deflection element (15) has a width extension (15b) which is between 75% and 120%, preferably 100%, of a feed line width (9b) of the feed line opening (9). 9. Internal combustion engine (20) according to one of claims 1 to 8, characterized in that the charge gas is recirculated exhaust gas from the internal combustion engine (20) or a mixture of exhaust gas and fresh air. 7/15 AT 520 741 B1 2019-07-15 Austrian Patent Office 10. Internal combustion engine (20) according to one of claims 1 to 9, characterized in that at least one discharge duct (4) opens into an intake line (8) leading to a cylinder of the internal combustion engine (20), each discharge duct (4) preferably in exactly an intake line (8) leading to a cylinder of the internal combustion engine (20) opens.