EP1019618A1

EP1019618A1 - Exhaust collector flange for an internal combustion engine

Info

Publication number: EP1019618A1
Application number: EP98955335A
Authority: EP
Inventors: Wolfgang Kleiner; Hans A. Härle; Albrecht Geiger; Helmut Held
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-10-02
Filing date: 1998-09-15
Publication date: 2000-07-19
Also published as: AU1223399A; DE19881446D2; WO1999018336A1

Abstract

The invention relates to an exhaust collector flange for an internal combustion engine, comprising a base part with cavities (21) for exhaust pipes (32) and openings (23) to cylinder entrances on the engine block of the internal combustion engine, and delivery means for secondary air and/or recirculated exhaust gases. Said delivery means are connected to the openings to the cylinder entrances. According to the invention, the delivery means comprise a channel positioned directly on the base part. A cover element (22) which only extends over a partial area of the base part is provided for forming said channel.

Description

"Exhaust manifold flange for an internal combustion engine"

The invention relates to an exhaust manifold flange for an internal combustion engine according to the preamble of claim 1.

State of the art:

In order to minimize pollutants in exhaust gas streams from internal combustion engines, so-called secondary air and / or recirculated exhaust gas has recently been fed into the combustion chamber of the engine. This influences the combustion reaction of the engine in such a way that the formation of undesired reaction products such as NOx and SOx is significantly reduced.

In known embodiments, the secondary air and / or the recirculated exhaust gas is preferably fed in via air guidance systems which are external components of forged and cast manifold flanges. However, the connection channels required for this from an air inlet system to the exhaust manifold flange and thus to the combustion chamber are associated with a large manufacturing outlay and thus high manufacturing costs. This led to the design of exhaust manifold flanges in a multi-layer construction (sandwich construction of at least three layers) in such a way that recesses in the form of channels were made in their middle layer. The layers in question (individual flanges) are regularly manufactured as stamped flanges and are then congruently placed on top of one another and soldered using holding devices. The copper solder required for the hard soldering of the individual layers is introduced in the form of solder paste into recesses (solder deposits) provided for this purpose in the individual flanges overlying the lowest layer. To ensure congruence, i.e. the positional stability of the individual layers, the individual partial flanges must also be welded to one another at several points before the soldering or heat treatment process.

The manufacturing process can be summarized as follows:

1. Production of the individual punch flanges with solder deposits

2. Congruent positioning of the individual layers on top of one another in special holding devices

3. Welding the individual layers on the circumference of the flange package

4. Application of solder paste into the solder deposits

5. Brazing the individual layers and the pipe socket under a protective gas atmosphere

Embodiments produced in this way are associated with an enormous use of materials and energy. This leads to high environmental and resource pollution. In addition, the high weight contributes to an unfavorable fuel consumption balance in motor vehicles. In addition to the very costly manufacturing process for cast and forged gas manifold flanges, the disadvantages of layer flange designs are even more diverse and therefore to be considered in more detail.

The following problems can arise in connection with the production of "exhaust manifold flanges with secondary and / or exhaust gas recirculation channels" by means of sandwich construction:

a) The process-reliable soldering of the relatively large-area layer flanges requires a very good flatness of the individual flange surfaces lying on top of each other. Non-uniformities in the flange surfaces lead to changed capillary filling forces and thus to different soldering qualities, which can result in inadequate strength of the soldered connection.

b) Large quantities of solder are required for the complete soldering of these relatively large-area layers, which drive up the total production costs.

c) The previous welding necessary to maintain the positional stability of the individual layers is an additional energy and cost-intensive production step.

d) The duct configuration used up to now is very cost-intensive in terms of material and manufacturing technology, since the complete middle flange layer only serves to create volume for the secondary air duct. A large part of the flange layer mass remaining around the channel is therefore of non-functional importance and unnecessarily represents almost 30% of the total weight of the flange. e) The complete heating necessary for the soldering process (100% heat penetration is required) of the flange package to soldering temperatures up to approx. 1080 ° C is only possible with high energy expenditure due to the relatively large and compact flange package mass.

f) The heat distortion caused by the soldering process in the form of concave or convex surface curvatures of the flange package must be compensated for by cost-intensive reworking.

g) The welding of the elbow and the soldered flange package can lead to the diffusion of the solder melt into the weld joint due to the local heating of the braze to the welding temperature, which can lead to a loss of strength of the weld seam.

Object and advantages of the invention:

The invention is based on the object of providing an exhaust manifold flange which can be produced more cost-effectively, with comparatively less material and energy expenditure and thus in a more resource-efficient manner. A weight saving is to be achieved with which a reduction in fuel consumption is achieved

Can bring internal combustion engines of motor vehicles.

This object is solved by the features of claim 1.

Advantageous and expedient developments of the device according to the invention are specified in the subclaims. The invention is based on an exhaust manifold flange for an internal combustion engine, which has a base part with recesses for exhaust ports and openings Cylinder accesses in the engine block of the engine as well as supply means for secondary air and / or recirculated exhaust gas comprises, the supply means being connected to the openings to the cylinder accesses. The essence of the invention is that the feed means comprise a channel arranged directly on the base part, for the formation of which at least one cover element is provided, which extends only over a partial area of the base part. This simplified structure results in significant material and weight savings compared to exhaust manifold flanges known in the prior art with integrated secondary air or exhaust gas recirculation channels.

In a further preferred embodiment of the invention, holes are provided for fastening the exhaust manifold flange and / or for securely connecting the openings in the base part to the cylinder accesses on the engine block in at least one cover element and in the base part, which can be penetrated by a screw connection. This measure has the advantage that the fastening of the cover element on the base part, the fastening of the exhaust manifold flange and the establishment of a tight connection of the secondary or

Exhaust gas recirculation duct on the engine block is made by the same screw connections. Furthermore, if the cover element, as described further below, is soldered to the base part, this prevents the solder joints from being thrown open or bursting, especially at high engine temperatures.

In a particularly preferred further embodiment of the invention, a sleeve element is fitted in at least one bore arrangement for the attachment of a screw connection in such a way that the sleeve after a predetermined deformation of the at least one cover element and / or the base part by the forces of the screw connection or connections absorbs further deformation forces on at least the cover element. In a preferred embodiment, the sleeve element is designed such that it is supported between a contact surface of the screw connection and the engine block in order to absorb forces that would cause undesirable deformations. By means of these measures according to the invention, the cover element for forming the channel can be made of comparatively thin-walled elastic material without running the risk that the cover element will give way to the screw connections until the entire manifold flange is detached, in particular in the area of the connection openings to the engine block. This would cause the engine to malfunction. The use of a thin-walled cover element saves manufacturing costs and reduces the weight of the exhaust manifold flange, which ultimately reduces fuel consumption.

In order to obtain a gas-tight design of the channel, it is also advantageous if the elements for channel formation are soldered to the base part or similarly connected.

Particularly when using sleeve elements according to the invention, particularly effective soldering can be achieved. Because the sleeve elements can be used before the soldering as position aids for the exact arrangement of the cover element on the base part by inserting them through the holes in the cover element and base part and if necessary. be jammed. The sleeve can advantageously be fixed by means of an interference fit. This is a stapling of the cover element on the base part z. B. unnecessary by welding spots before soldering.

In order to reliably avoid detachment of the manifold flange at high temperatures of the internal combustion engine, it is furthermore advantageous if means for stiffening the base part are provided on the base part. In a preferred embodiment, the means for stiffening comprise a flange that extends at least partially over the outer contour of the base part. In this context, it is also preferred if the base part is made from a steel sheet.

In order to achieve a particularly simple construction, it is also preferred if the cover element is shell-shaped to form the channel and rests on the base part. In the case of a flanging on the base part, it is also advantageous for this embodiment if the upturned areas on the cover element to form the shell lie against the flanging of the base part by suitable dimensions of the cover element, as if, as it were, two shells with the open side fit exactly into one another become. In this case, too, a previous fixing of the cover element by the precise insertion before z. B. a soldering process is not required. The adjacent flanges or upstands offer good flow paths for the solder. The channel cross-section can also be determined via the height of the upstand on the cover element or the flanging on the base part.

In a likewise advantageous embodiment of the invention, the cover element is a cover plate which is congruently arranged to form the channel on an intermediate plate lying on the base part with cutouts for the channel guides. This represents a comparatively simple solution, in which the channel parts z. B. can be produced by simple punching.

In order to be able to use existing flanges on the base part for channel formation, it is also preferred if the cover element has an L or U profile shape. To use standard components for channel formation, it is also advantageous if the cover element comprises a square tube which is placed on the base part.

It is also advantageous if the cover element is formed from a part of the base part by bending it into a box profile. In this way, the base element with secondary and / or exhaust gas recirculation channel can be made from a single sheet.

Finally, it is particularly preferred if the exhaust ports are soldered into the base part. This avoids an advantage of the flange and possibly cracking on the flange, which occurs during an otherwise usual welding process.

Drawings:

Three exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description, giving further advantages and details.

Show it

Fig. 1 shows a first invention

Exhaust manifold flange in top view,

1A-F sectional views of the embodiment of FIG. 1 according to the section lines A-A to F-F shown in FIG. 1,

Fig. 2 is a side view of the 1 according to the exemplary embodiment,

Fig. 3 shows a second invention

Exemplary embodiment of an exhaust manifold flange in plan view,

3A is a sectional view of the

3 along the section line A-A in Fig. 3,

Fig. 4 shows a third invention

Embodiment of an exhaust manifold flange in plan view and

4A - F different sectional views of the

4 along the section lines A-A to F-F shown in Fig. 4.

Description of the embodiments:

1 and 2, a first embodiment of the invention is shown. The sections AA to FF according to FIGS. 1A-1F are intended to further illustrate the exemplary embodiment. This exemplary embodiment comprises a base part 1 with four receiving openings 2 for each exhaust pipe 14 (see FIG. 1A) corresponding to the number of cylinders of an engine. Furthermore, this exhaust manifold flange has an intermediate plate 3 running along the manifold receiving openings, which has a recess 4 (shown in broken lines in FIG. 1) and, together with a congruent cover plate 5, forms a secondary air and / or exhaust gas recirculation channel arranged directly on the base part 1. The intermediate plate 3 is with the base part 1 and the cover plate 5 z. B. soldered to obtain the desired gas tightness of the secondary air and / or exhaust gas recirculation channel. Furthermore, the base part 1 is fastened together with the intermediate plate 3 and the cover plate 5 via screw connections 6 (only shown in the sectional view of FIG. 1A) to an engine block (not shown), for example. For this purpose, holes 7, 8 are provided in the base part 1 and in the cover plate 5 (see FIG. 1A). For further fastening of the exhaust manifold flange to an engine block, 2 further bores 13 are positioned on the base part 1 above each receiving opening. In order to provide access of the secondary air duct to the corresponding cylinder opening on an engine block, the base part 1 has openings 9 which are encompassed by the recess 4 in the cylinder plate 3. The cover plate 5 has a feed connector 10 for feeding secondary air and / or recirculated exhaust gas into the recess 4 of the channel

Edging 11, 12 on. The flanges give the base part a very high stiffness, in particular bending stiffness, so that with a given maximum bending stiffness, the entire flange made of very thin steel sheet, ie. H. can be manufactured with very little material.

3 and 3A show a second exemplary embodiment of an exhaust manifold flange according to the invention, in which a base part 20 which is similar in comparison to the first exemplary embodiment is used. The base part also comprises four receiving openings 21 for a corresponding number of exhaust ports.

In contrast to the first exemplary embodiment, however, only the secondary air and / or exhaust gas recirculation duct is formed a cover element 22 is used, which is shaped like a bowl (see section-wise representation in FIG. 3 and FIG. 3A). The shell-shaped cover element 22 sits directly on the base part 20, the channel volume formed thereby being connected to openings 23 which provide access to corresponding cylinder openings on an engine block. To attach this exhaust manifold flange with z. B. screws are provided on the base part 20 and in the cover element 22 holes 24, 25 or above the receiving openings 21 holes 26.

A sleeve 27 is inserted into the congruent bores 24 and 25, as can be seen in FIG. 3A. The sleeve 27 has a collar 28 which rests on the cover element 22. The sleeve 27 according to the invention has several advantages. First, it serves as a positioning aid for the cover element 22 in front of a z. B. Brazing process. For this purpose, the sleeve 27 is inserted through the bore 24 in the cover element 22 and into the bore 25 of the base part. In the case of a precisely fitting design of the sleeve (this can also be easily pressed in as in a press fit), the cover element 22 is exactly positioned and fixed with respect to the base part 20, so that it is not necessary, for example, to attach welding tack points before a brazing process. However, the brazing process is carried out so that the sleeve 27 is still movable in the bore 25 of the base part 20. By this measure, when tightening a screw 29, the screw head 30 of which rests on the collar 28 of the sleeve 27, the cover element 22 is only deformed until the end of the sleeve 27 located in the bore 25 of the base part 20 abuts an engine block (not shown).

FIG. 3A shows the relaxed state in which the end of the sleeve 27 located in the bore 25 is at a slight distance from the contact surface 31 of the base part 20, which rests on an engine block in the installed state "x" owns. Only in this area is deformation of the cover element 22 permitted. This measure thus prevents a z. B. thin sheet metal produced cover element 22 yields until the base part 20 can stand out from an engine block, which can ultimately lead to a leak between supply channels to an engine block and the openings 23 in the base part 20. Due to the size of the distance x between the end of the sleeve 27 and the contact surface 31 of the base part in a relaxed state, the size of the contact pressure on the cover element 22 and thus the base part 20 can be adjusted so that there is no permanent deformation of the cover element.

In the sectional view of FIG. 3A, an exhaust nozzle 32 inserted into the receiving openings 21 is shown in the left half. This can e.g. B. soldered instead of a welding process to avoid cracking in the high thermal load during welding in the bottle. In order to increase the rigidity of the base part 20, this has a flange 33 with the exception of the peripheral region on which the cover element 22 runs.

A third exemplary embodiment according to the invention is shown in FIG. 4 and the associated cuts. 4A-F shown along the section lines A-A to F-F. The exemplary embodiment comprises a base part 40 which is identical to the first exemplary embodiment, with the only difference that the outer flange 41 on the base part 40 is fully circumferential. Comparable construction elements are therefore provided with the same reference symbols.

In order to form a secondary air and / or exhaust gas recirculation channel, a shell-shaped cover element 42 is inserted into the base part 40 in such a way that the raised areas of the cover element 42 on the circumferential flange 41 of the base part 40 with the exception of one Section in the area of the two outer receiving openings 2 for exhaust pipe 43 (only indicated in Fig. 4A). In order to replace the flanging which is missing at the end points in the area of the two outer receiving openings 2 for exhaust ports 43 for the cover element 42 ending there, web elements 44 are provided which take over this task. In order to obtain a tight duct system, the cover element is soldered to the base part along the edge of the cover element. This shell construction results in a very high rigidity of the exhaust manifold flange, so that advantageously the individual shells (base part 40 and cover element 42) made of very thin, e.g. B. sheet steel, ie can be produced with very little material. According to the sectional drawings in FIGS. A to F, the base part 40 and the cover element 42 are designed in such a way that they can be inserted into one another in a simple manner in a positionally stable manner with the open sides pointing towards one another and possibly pressed together. In addition to the channel design shown in the drawing, larger channel cross sections can also be achieved without problems by varying the height of the flange 41 of the base part 40 and / or the edging of the cover element 42. For fastening the exhaust manifold flange, bores 13, 45, 46 are provided in the base part 40 and possibly in the cover element 42 (see in particular FIG. 4A, in which a screw connection 47 is indicated).

In order to prevent the cover element 42 from being deformed in an undesired manner at the points at which the exhaust manifold flange is screwed together with the base part 40 and the cover element 42, these points are underlaid or supported by sleeve or support elements 48.

In the case of the exemplary embodiments according to the invention, the work steps 1 - 3 mentioned at the beginning in the prior art are omitted due to the low use of materials resources are conserved and the weight saving of over 50% compared to conventional embodiments can save fuel in motor vehicles. This in turn leads to environmental protection. In the exemplary embodiments according to the invention, moreover, there is no interaction between the molten solder and the welded joints or problematic solder diffusion. Overall, the manufacturing costs are also greatly reduced by using a much lower amount of solder.

Reference symbol list:

1 base part 40 base part

2 opening 41 flanging

3 intermediate plate 42 cover element

4 Cut-out 43 Exhaust nozzle

5 cover plate 44 web elements

6 screw connection 45 hole

7 hole 46 hole

8 Hole 47 screw connection

9 opening 48 sleeve element

10 feed nozzles

11 flanging

12 flanging

13 hole

14 flue gas spigot

20 base part

21 receiving opening

22 cover element

23 opening

24 hole

25 hole

26 hole

27 sleeve

28 collar

29 screws

30 screw head

31 loading area

32 exhaust pipe

33 flanging

Claims

Expectations:

1. exhaust manifold flange for an internal combustion engine, which comprises a base part with recesses (2) for exhaust ports (14, 32, 43) and openings (9, 33) to cylinder accesses to the engine block of the engine and supply means for secondary air and / or recirculated exhaust gas, the Feed means are connected to the openings to the cylinder accesses, characterized in that the feed means comprise a channel arranged directly on the base part, for the formation of which at least one cover element (5, 22, 42) is provided, which extends only over a partial area of the base part (1, 20, 40) extends.

2. Exhaust manifold flange according to claim 1, characterized in that for fastening the exhaust manifold flange and / or for securely connecting the openings in the base part to the cylinder accesses on the engine block in at least one cover element (5, 22, 42) and in the base part (1, 20, 40 ) bores (7, 8; 24, 25; 45, 46) arranged one above the other are provided, which can be penetrated by a screw connection (6, 29, 47).

3. exhaust manifold flange according to claim 2, characterized in that in at least one bore arrangement (7, 8; 24, 25; 45, 46) a sleeve element (27, 48) is fitted such that the sleeve after a predetermined deformation of the at least one cover element and / or the base part absorbs further deformation forces on at least the cover element due to the forces of the screw connection.

4. Exhaust manifold flange according to one of the preceding Claims, characterized in that the elements (3, 5, 22, 42) for channel formation are soldered to the base part (1, 20, 40).

5. Exhaust manifold flange according to one of the preceding claims, characterized in that on

Base part (1, 20, 40) means are provided for stiffening the base part.

6. exhaust manifold flange according to claim 5, characterized in that the means for stiffening comprise a flange (11, 12, 33, 41) which extends at least partially over the outer contour of the base part.

7. Exhaust manifold flange according to one of the preceding claims, characterized in that the base part (1, 20, 40) consists of a steel sheet.

8. Exhaust manifold flange according to one of claims 1 to 7, characterized in that the at least one cover element (22, 42) is shell-shaped and rests on the base part to form the channel.

9. Exhaust manifold flange according to one of claims 1 to 7, characterized in that the at least one cover element is a cover plate (5) which is congruent to form the channel on an intermediate plate lying on the base part (3) with recesses (4) for the channel guide is arranged.

10. Exhaust manifold flange according to one of claims 1 to 7, characterized in that the at least one cover element has an L or U profile that cooperates with a correspondingly prepared area of the base part to form the channel.

11. Exhaust manifold flange according to one of claims 1 to 7, characterized in that the at least one cover element comprises a square tube which is placed on the base part.

12. Exhaust manifold flange according to one of claims 1 to 7, characterized in that the cover element is formed from part of the base part by this being bent into a box profile.

13. Exhaust manifold flange according to one of the preceding claims, characterized in that the exhaust pipe (14, 32, 43) in the base part (1, 20, 40) is soldered.