EP2407649B1 - Flange plate, flange connection and exhaust manifold - Google Patents

Description

The present invention relates to a flange plate for connecting exhaust pipes to an internal combustion engine. The invention also relates to a flange connection for fastening an exhaust system to an internal combustion engine. Furthermore, the present invention relates to an exhaust manifold for discharging exhaust gas from an internal combustion engine, in particular a motor vehicle.

An exhaust system is usually attached on the input side to an internal combustion engine in order to dissipate the resulting during operation of the internal combustion engine combustion exhaust gases can. The fixed to an engine block or on a cylinder bank of the engine input area of the exhaust system is usually formed by a so-called exhaust manifold, which combines a plurality of individual, inlet side exhaust pipes to a common outlet side exhaust pipe. Usually, the individual exhaust pipes are fastened via a common flange on the internal combustion engine. The problem with this is that during operation of the internal combustion engine high temperatures arise on the exhaust side, which lead to thermal expansion effects. Due to different temperatures on the one hand on the engine block or on the cylinder bank and on the other hand on the flange of the exhaust system and the exhaust manifold and / or due to different thermal expansion coefficients of the interconnected components can lead to thermally induced stresses within the interconnected components or within the compound. In particular, these voltages can lead to bulging in the region of the common flange, so that leakages occur there, through which exhaust gas can pass untreated into the environment.

From the EP 1 229 221 A1 a flange plate for connecting exhaust pipes with an internal combustion engine is known, which is equipped with at least two integrally formed on the flange plate connecting piece, to each of which an exhaust pipe is fastened, and with a plurality of through holes for fixing the flange plate to the internal combustion engine. In this known flange plate on a side facing the internal combustion engine, a groove-like channel is formed, can be supplied via the secondary air.

From the EP 0 861 975 A2 Another flange plate of this type is known, which in each case has a flanging to achieve a particularly high bending stiffness along its outer circumference and along the respective inner circumference of the respective, each receiving a connecting piece opening.

Also the JP 2001-207842 A shows a stiffened flange plate which is provided at its outer periphery and at the inner peripheries of their openings each with a circulation.

The present invention addresses the problem of finding a way for the connection between the exhaust system and the internal combustion engine, which is characterized in particular by the fact that the risk of damage to the interconnected components due to thermal expansion effects is reduced.

This problem is solved according to the invention by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea, a flange plate having at least two integrally formed on the flange plate connecting piece, to each of which an exhaust pipe is fastened, and the plurality provided for fixing the flange plate to the internal combustion engine, e.g. suitable for performing screws, through-openings has to be provided with at least one connection portion having at least one of the connecting piece, and which is bordered by a flange plate penetrating the slot. In order for said connection region to remain connected to the flange plate in spite of the slot, the respective slot has at least one interruption, in the region of which the respective connection region remains connected to the remaining flange plate, while otherwise being separated from the flange plate along the slot. This construction means that the connection area can move with the respective connecting piece relative to the rest of the flange plate. As a result, thermally induced strains can be absorbed elastically, whereby the risk of critical stresses can be reduced. The invention is based on the consideration that the connecting pieces reach higher temperatures than the flange plate connected to the internal combustion engine. With the help of the respective slot, the respective connection region, which contains the respective connection piece, is cut free from the remaining connection plate and separated, so that the connection pieces with the attached exhaust pipes can move relative to the remaining connection plate and thus relative to the internal combustion engine , Furthermore, the risk of dents due to thermal expansion effects is significantly reduced, especially in the area of the connection piece or in the connection areas.

According to a preferred embodiment, the respective slot extends within the bottle plate separately and spaced from nozzle openings, the each enclosed by a connecting piece and each penetrate the flange plate. In other words, the respective slot extends outside the outlet port or outside the port openings. As a result, for example, leaks can be avoided, which could then occur if the respective slot would open into such a nozzle opening or two such nozzle openings would fluidly interconnect.

Additionally or alternatively, it can be provided that the respective slot within the bottle plate runs separately and at a distance from the passage openings, ie outside the passage openings. This allows e.g. avoid adverse interactions with the fixation of the flange plate.

Also advantageous is an embodiment in which the respective slot is closed at its longitudinal ends or opens into another slot. This ensures that the respective slot extends completely within the flange plate. For example, this can prevent leaks.

Appropriately, it can be provided that a slot width of the respective slot is smaller than or at most equal to a plate thickness of the flange plate. Since the slots are intended to effect only a separation of the plate areas adjacent to the slot length laterally, a small slot width is sufficient, which at certain temperatures can also assume the value zero, so that the plate areas abut one another in the slot. For example, the slots can be produced by means of a laser cutting process or by means of a punching or cutting or separating process.

According to the invention, the passage openings are arranged outside the respective connection area in the remaining flange plate. Thus, in the mounted state, the rest of the flange plate in the region of the passage openings on the internal combustion engine fixed in position, while the largely cut-free terminal portions are movable relative thereto.

In another advantageous embodiment, a plurality of connecting pieces may each be formed in such a connection region. Preferably, all connecting pieces are each formed in such a connection region. Thus, all the connecting pieces can move relative to the rest of the flange plate.

In another advantageous embodiment, at least one such interruption between the respective connecting piece and a thereto adjacent passage opening may be arranged. This is particularly advantageous, since the respective passage opening represents an attachment point, in which the position fixing takes place between the internal combustion engine and the flange plate. Thus, there is no or only comparatively small in operation in the region of the respective attachment opening Optionally, it can be provided to allow the slots of the associated adjacent connection areas to merge into one another in the region of such a tongue and / or to provide them with a common section. As a result, particularly large relative movements between the areas adjacent to each other via a slot of the flange plate are made possible.

According to another advantageous embodiment, at least one such connection region in the region of at least one such interruption may comprise a connecting web which extends substantially radially in the direction of an adjacent through-opening with respect to the associated connecting piece and which is bordered laterally by slot sections, which are in particular parallel to the respective connecting web extend. For such a slot geometry, the mobility of the largely freely cut connection areas is improved compared to the rest of the flange plate.

The problem underlying the invention is achieved within a flange connection, which serves for fastening an exhaust system to an internal combustion engine, by the use of a flange plate of the type described above, are attached to the connecting piece exhaust pipes of the exhaust system. In addition to the flange plate, the flange connection also comprises at least one pressure plate which is arranged on the flange plate on a side remote from the internal combustion engine and which is screwed to the internal combustion engine through the passage openings of the flange plate. In particular, such a pressure plate may have at least one passage opening through which the respective connection piece is connected to the respective connection pipe. For this purpose, the respective connecting piece protrudes into this passage opening of the respective pressure plate or through it.

The problem underlying the invention is also solved by an exhaust manifold, which serves for discharging exhaust gas from an internal combustion engine, in particular a motor vehicle, wherein the exhaust manifold has a plurality of exhaust pipes, which are each fluidly connectable to a combustion chamber of a cylinder of the internal combustion engine. The exhaust manifold according to the invention now has a flange plate of the type described above, the connecting pieces are firmly connected to the exhaust pipes.

It is clear that the present invention basically also relates to an exhaust system for an internal combustion engine, in particular of a motor vehicle, having such an exhaust manifold.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Fig. 1

eine stark vereinfachte Prinzipdarstellung einer Brennkraftmaschine mit Abgasanlage,

Fig. 2

eine perspektivische Schnittdarstellung im Bereich einer Flanschverbindung,

Fig. 3

eine Draufsicht auf eine Flanschplatte,

Fig. 4

eine Schnittdarstellung wie in Fig. 2, jedoch bei einer anderen Ausführungsform.

Show, in each case schematically,

Fig. 1

a greatly simplified schematic representation of an internal combustion engine with exhaust system,

Fig. 2

a perspective sectional view in the region of a flange connection,

Fig. 3

a top view of a flange plate,

Fig. 4

a sectional view as in Fig. 2 but in another embodiment.

Corresponding Fig. 1 For example, an internal combustion engine 1 may be equipped in the usual way with a fresh air system 2 and with an exhaust system 3. In the example, the internal combustion engine 1 has an engine block 4, which contains a plurality of cylinders 5, each enclosing a combustion chamber 6. Instead of a single cylinder block 4, the internal combustion engine 1 may also have two cylinder banks, z. Eg with a V-engine.

The fresh air system 2 is used to supply fresh air 7 to the cylinders 5 and to the combustion chambers 6. For this purpose, the fresh air system 2 is mounted on the output side of the engine block 4.

The exhaust system 3 serves to discharge exhaust gas 8 from the cylinders 5 and from the combustion chambers 6. For this purpose, the exhaust system 3 is attached to the engine block 4 on the input side. The exhaust system 3 has on the input side an exhaust manifold 9, which has an exhaust pipe 10 for each cylinder 5 and is connected via a common pipe 11 with the rest of the exhaust system 3. Furthermore, the exhaust manifold 9 comprises a flange 12, with which all exhaust pipes 10 of the exhaust manifold 9 are fixed to the engine block 4. With the aid of this flange 12 is thus a flange 13 for attaching the exhaust system 3 to the internal combustion engine 1 or at the engine block 4 realized.

Preferred embodiments of this flange connection 13 will be described with reference to FIGS Fig. 2 and 4 explained in more detail.

According to the Fig. 2 and 4 The flange connection 13 comprises a flange plate 14, which is also in Fig. 3 is shown. The flange plate 14 has for each exhaust pipe 10 to a connection piece 15 to which the respective exhaust pipe 10 can be attached. Furthermore, the flange connection 13 according to the Fig. 2 and 4 at least one pressure plate 16 which is arranged on the flange plate 14 within the flange connection 13 on a side remote from the internal combustion engine 1 or from the engine block 4. The pressure plate 16 is fastened by the flange plate 14 to the internal combustion engine 1 or to the engine block 4.

The pressure plate 16 has at least one large opening 17 through which the connecting piece 15 of the flange plate 14 protrudes. Furthermore, the pressure plate 16 has at least one small opening 18 through which a screw or threaded rod for screwing the pressure plate 16 to the engine block 4 can be guided. So that this screw connection can take place through the flange plate 14, the flange plate 14 is in accordance with FIG Fig. 3 a plurality of through holes 19, through which the respective screw or threaded rod can be guided. Consequently, the respective passage opening 19 serves to fix the flange plate 14 on the engine block 4 or on the internal combustion engine 1.

The respective small opening 18 of the pressure plate 16 is arranged in alignment with one of the passage openings 19 of the flange plate 14.

The flange 12 is thus ultimately formed by the flange plate 14 and the at least one pressure plate 16.

Visible, the flange plate 14 may be thinner than the pressure plate 16, e.g. in the ratio 2/3. For example, the flange plate 14 has a thickness of 2 mm, while the pressure plate 16 has a thickness of 3 mm. In particular, the pressure plate 16 is formed as a sheet metal part or sheet metal part.

The engine block 4 includes in the region of the respective connecting piece 15 an outlet opening 20, which leads to the respective cylinder 5 and to the respective combustion chamber 6. In the example, the engine block 4 in the region of the outlet opening 20 also has an annular step 21 into which a seal 22, in particular a carbon seal, is inserted. For example, the respective exhaust pipe 10 can project through the connecting piece 15 through into the region of the outlet opening 20, so that the seal 22 then comes to bear sealingly against the respective exhaust pipe 10. In the example of Fig. 4 extends the exhaust pipe 10 freestanding in the outlet opening 20 and the seal 22 comes in this case axially sealingly against the flange plate 14 to the plant. In principle, a combination is conceivable in which the seal 22 is sealingly abutting both radially on the exhaust pipe 10 and axially on the flange plate 14.

At the in Fig. 4 In the embodiment shown, the exhaust manifold 9 is equipped with an outer shell 32, which largely encloses the exhaust pipes 10. Consequently, this is an air gap-insulated exhaust manifold 9 with largely inner exhaust pipes 10. To attach the exhaust pipes 10 and the exhaust manifold 9 to the flange plate 14 and to the outlet 15 welds 33 are preferred. Fig. 4 shows an exemplary designed as a three-sheet seam weld 33, which connects the outlet pipe 15, the exhaust pipe 10 and the outer shell 32 each with each other.

According to Fig. 3 has the flange plate 14 corresponding to the number of cylinders 5 a plurality of connecting pieces 15 which are integrally formed on the flange plate 14. For example, the connecting pieces 15 are formed by deep drawing a flat sheet metal blank. The respective connecting piece 15 in each case forms an enclosure for a nozzle opening 34, which penetrates the flange plate 14.

In the example, the internal combustion engine 1 has four cylinders 5 without restricting the generality. Accordingly, the flange plate 14 has four connecting pieces 15 here. At each connecting piece 15, one of the exhaust pipes 10 of the exhaust manifold 9 can be fastened.

As already stated, the connection plate 14 has a plurality of passage openings 19 for its fixation on the internal combustion engine 1, through which screws or threaded rods for fastening the flange plate 14 or the flange 12 to the internal combustion engine 1 or to the engine block 4 can be made.

At least one of the connecting pieces 15 is formed in a connection region 23. Preferably, a plurality of connecting pieces 15 are each formed in such a connection region 23. In the preferred embodiment shown here, all connecting pieces 15 are each formed in such a connecting region 23. The respective connection region 23 is characterized in that it is enclosed by a slot 24, which the Flange plate 14 penetrates. In this case, the connection regions 23 are not completely separated from the remaining flange plate 14, but the respective slot 24 has at least one interruption 25. The slots 24 therefore do not completely surround the respective connection region 23, but in each case with at least one interruption 25. In the region of the respective interruption 25, the respective connection region 23 is connected to the remaining flange plate 14. By contrast, the respective connection region 23 is separated from the remaining flange plate 14 in the region of the remaining slot 24.

Recognizable extends now the respective slot 24 within the bottle plate 14 separately and spaced from the nozzle openings 34. In addition, the respective slot 24 within the bottle plate 14 also extends separately and spaced from the through holes 19th

Furthermore, it can be seen that the respective slot 24 is closed at its longitudinal ends 35 or opens into another slot 24.

In the embodiment shown, an in Fig. 3 shown slot width 36 of the respective slot 24 is the same size as a maximum Fig. 4 Preferably, the slot width 36 is smaller, for example at least 50% smaller than the plate thickness 37th

Particularly expedient is the embodiment shown here, in which the passage openings 19 are arranged outside of the respective connection region 23, that is, in the remaining flange plate 14. As a result, relative movements between the connecting piece 15 and the through holes 19 are made possible, since the largely free cut Terminal areas 23 are movable relative to the rest of the flange plate 14 due to the slots 24.

In the embodiment shown here, the interruptions 25 of the slots 24 are each arranged in a region which is located approximately radially with respect to the respective connection piece 15 between the respective connection piece 15 and a passage opening 19 adjacent thereto. Furthermore, the respective slots 24 extend substantially coaxially or concentrically with the respective connecting piece 15. Thus, the slots 24 each have at least one circular arc-shaped portion 26 which extends coaxially with the respective connecting piece 15.

At the in Fig. 4 In the embodiment shown, the pressure plate 16 covers the slot 24 or the slot section 26.

At the in Fig. 3 In the embodiment shown, the respective connection region 23 also has at least one tongue 27 which extends from the associated connection piece 15 in the direction of the adjacent connection piece 15. The tongues 27 extend substantially radially to the respective connecting piece 15. The respective tongue 27 is appropriately bordered by the associated slot 24 without interruption. Thus, the tongues 27 are largely free to move relative to the rest of the flange plate 14.

Furthermore, the tongues 27 can be dimensioned such that in the region of such a tongue 27, the slots 24 of adjacent connection regions 23 merge into one another. A corresponding transition area or contact area is in Fig. 3 denoted by 28. Additionally or alternatively, the tongues 27 may be shaped such that the slots 24 of adjacent connection regions 23 have a common section 29. For example, encounter at the in Fig. 3 the embodiment shown embodiment, the two tongues 27 of the two inner terminal portions 23 along such a common portion 29 to each other.

Furthermore, according to the embodiment shown here, at least one such connection region 23 may have a connecting web 30 in the region of such an interruption 25. The respective connecting web 30 extends with respect to the associated connecting piece 15 substantially radially and in the direction of an adjacent passage opening 19. Furthermore, the respective connecting web 30 is laterally bordered by slot sections 31, which may extend in particular parallel to the respective connecting web 30. It is important that said side slot portions 31 terminate in front of the respective through-opening 19, so that the associated connection region 23 remains in contact via the respective connecting web 30 with the remaining flange plate 14.

In the case of a thermal load in the region of the flange connection 13, the flange 12 expands differently than the internal combustion engine 1 or the engine block 4. This leads to relative movements of the exhaust pipes 10 relative to the engine block 4, which can be largely compensated by the flange plate 14 presented here. While the through holes 19 are connected via the screw connection within the flange 13 fixed to the engine block 4, the exhaust pipes 10 are fixedly connected to the connecting piece 15. However, the connecting pieces 15 are each arranged in a connection region 23, which is movable relative to the rest of the flange plate 14 due to the respective slot 24. As a result, 1 relative movements between the exhaust pipes 10 and the engine block 4 can occur during operation of the internal combustion engine, which take place in the elastic region of the connection plate 14 and thereby reversible, which is the risk of permanent damage reduced. At the same time the risk of dents is significantly reduced in the respective connection area 23, which could lead to undesirable leakage of hot exhaust gases.

Claims (14)

1. A flange plate for connecting exhaust pipes (10) to an internal combustion engine (1), with at least two connecting pieces (15) integrally formed on the flange plate (14), to each of which an exhaust pipe (10) can be fastened, and with multiple passage openings (19) for fixing the flange plate (14) to the internal combustion engine (1), characterized in that at least one of the connecting pieces (15) is formed in a connecting region (23), which is surrounded by a slit (24) penetrating the flange plate (14), which comprises at least one interruption (25), wherein the respective connecting region (23) is connected to the remaining flange plate (14) only in the region of the respective interruption (25), wherein the passage openings (19) are arranged outside the respective connecting region (23) in the remaining flange plate (14), so that the connecting region (23) with the respective connecting piece (15) can move relative to the remaining flange plate (14) when the flange plate (14) is fixed to the internal combustion engine (1) in the region of the passage openings (19).
2. The flange plate according to Claim 1, characterized in that the respective slit (24) within the flange plate (14) runs separately and spaced from connecting piece openings (34), which are each surrounded by a connecting piece (15) and each penetrate the flange plate (14).
3. The flange plate according to Claim 1 or 2, characterized in that the respective slit (24) within the flange plate (14) runs separately and spaced from the passage openings (19).
4. The flange plate according to any one of the Claims 1 to 3, characterized in that the respective slit (24) at its longitudinal ends (35) is closed or opens into another slit (24).
5. The flange plate according to any one of the Claims 1 to 4, characterized in that a slit width (36) of the respective slit (24) is smaller than or maximally equal in size as a plate thickness (37) of the flange plate (14).
6. The flange plate according to any one of the Claims 1 to 5, characterized in that multiple connecting pieces (15) are each formed in such a connecting region (23).
7. The flange plate according to any one of the Claims 1 to 6, characterized in that all connecting pieces (15) are each formed in such a connecting region (23).
8. The flange plate according to any one of the Claims 1 to 7, characterized in that at least one such interruption (25) is arranged between the respective connecting piece (15) and a passage opening (19) adjoined thereto.
9. The flange plate according to any one of the Claims 1 to 8, characterized in that at least one such slit (24) has at least a section (26) in the shape of an arc of a circle, which is arranged coaxially to the respective connecting piece (15).
10. The flange plate according to any one of the Claims 1 to 9, characterized in that at least one such connecting region (23) comprises at least one lug (27), which extends from the associated connecting piece (15) in the direction of an adjacent connecting piece (15).
11. The flange plate according to Claim 10, characterized

    - in that the respective slit (24) encloses the respective lug (27) without interruption, and/or

    - in that in the region of such a lug (27) the slits (24) of the associated adjacent connecting regions (23) merge into one another and/or have a common section (29).
12. The flange plate according to any one of the Claims 1 to 11, characterized in that at least one such connecting region (23) in the region of at least one such interruption (25) comprises a connecting web (30), which with respect to the associated connecting piece (15) radially extends in the direction of an adjacent passage openings (19) and which is laterally surrounded by slit sections (31), which can extend in particular parallel to the respective connecting web (30).
13. The flange for fastening an exhaust system (3) to an internal combustion engine (1),

    - with a flange plate (14) according to any one of the Claims 1 to 12, to the connecting pieces (15) of which exhaust pipes (10) of the exhaust system (3) are fastened,

    - with at least one pressure plate (16), which is arranged on the flange plate (14) on a side facing away from the internal combustion engine (1) and which is screwed to the internal combustion engine (1) through the passage openings (19) of the flange plate (14).
14. An exhaust manifold for discharging exhaust gas from an internal combustion engine (1), in particular of a motor vehicle,

    - with multiple exhaust pipes (10), each of which can be fluidically connected to a cylinder (5) of the internal combustion engine (1),

    - with a flange plate (14) according to any one of the Claims 1 to 12, the connecting pieces (15) of which are connected to the exhaust pipes (10) in a fixed manner.

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