EP1253302B1 - Exhaust silencer - Google Patents

Description

The invention relates to a silencer for an exhaust system an internal combustion engine, in particular one Motor vehicle.

In modern motor vehicles, the exhaust system must increasingly perform more complex tasks, such as Emission control and Soundproofing. Powerful components build regularly relatively large and have a correspondingly high weight, which also makes the exhaust system overall heavy having. There is a need to add the exhaust system the same performance easier to train.

Due to the relatively high exhaust gas temperatures, silencers become usually made of sheet steel. The usage lighter materials, e.g. Light metals or So far, plastics have failed due to the high manufacturing costs and / or in terms of temperature, chemical Resistance (e.g. salt and condensate) and extreme strength Material stresses. Further problems arise with the integration of the stainless steel pipes of the exhaust system into one Silencer made of such a light material.

DE 200 00 155 U1 is a silencer at the beginning known type known, which has a housing, the one and can be connected on the outlet side to pipes in the exhaust system is. There are functional elements inside the housing added. To save weight with this silencer To be able to, the housing is made of a glass fiber reinforced and heat stabilized polyphthalamide (PPA).

To the plastic housing of the known silencer to protect the hot exhaust gases, this can be a thermal insulation layer, for example made of rock wool. The Pipelines of the exhaust system are in the intake port of the Housing inserted, each between the pipeline and the associated receptacle a fitted heat and Crimp ring, e.g. made of Teflon or in the form of a compressed and pressed wire mesh.

The known silencer must be connected to it Pipelines are held on the vehicle, because fasteners, that attack the plastic housing are unsuitable, because the plastic case under the prevailing Thermal stress is relatively soft and creepable inclines. Furthermore, the effort for connection increases of the exhaust system to the vehicle body, as in the Operation soft plastic case no moments between the connected pipes can be transferred. To this extent it is reduced by using this known one Muffler the stability of the exhaust system. At the same time, this makes the handling of the complete one more difficult Exhaust system when it is mounted on the vehicle

Another exhaust silencer is known from EP 0 337 877 A1 known, the housing of a lower shell made of plastic and an upper shell made of plastic. An inflow pipe penetrates a first end wall of the housing through the halves of each shell is formed. The inflow pipe is wound in two snakes inside the case and goes directly into a drain pipe, which is a second end wall of the housing penetrates, which are also halves is formed on the two shells. Inside the case two transverse walls are arranged, the two front Separate rooms from a middle room and the one in the known one Exhaust silencer from the inflow-outflow pipe each are enforced three times. The ones running through the middle room are three sections of the inflow-outflow pipe perforated.

Another exhaust silencer is known from US 5,147,987, whose housing is a lower shell made of metal and a Has top shell made of metal. There are two partitions in the housing arranged that a middle inflow space laterally limit and on the one hand by a deflection space and on the other separate from an outflow space. The cross walls are each interspersed by two coupling tubes, each on both axial ends are open and thereby a communicating Enable connection of the deflection chamber with the outflow chamber. The transverse wall separating the inflow space from the deflection space is also with at least one through opening provided, through which the inflow space communicates with the deflection space. The housing has an inflow opening that is transverse opens into the centrally arranged inflow space, as well as a Outflow opening, which also opens transversely into the outflow space.

The present invention addresses the problem an embodiment for a silencer of the type mentioned to indicate which has a reduced weight and sufficient stability for the exhaust system guaranteed.

According to the invention, this problem is solved by a silencer solved with the features of claim 1.

The invention is based on the general idea of the housing the silencer from a lower shell (bottom part) and build up from an upper shell (lid), the lower shell self-supporting and made of metal and strong is connected to an inflow pipe and an outflow pipe, while the top shell is made of a plastic. Due to this design, the lower shell with the inside firmly integrated pipes have high rigidity and stability, while the top shell is a lightweight element. Overall, this results for the housing of the invention Silencer the required stability as well a significant weight reduction. It is essential here the division of the housing functions, namely the one hand Providing the required stability and strength, what is fulfilled by the bottom part, and on the other hand the provision a volume required for sound absorption, what is filled by the lid.

The inlet pipe and the outlet pipe of the silencer are can be connected to the corresponding pipes of the exhaust system or already form components or sections of the exhaust system. According to the invention there are two transverse walls in the bottom part permanently installed, to which those attached to the bottom part Support pipes radially. This construction allows the bottom part or the silencer transmit moments between act on the pipes.

According to a particularly advantageous embodiment areas of the muffler through which exhaust gas flows, such as. Pipe areas and room areas, essentially in Bottom part arranged and / or formed. Through this Construction is achieved that the hot exhaust gases are essentially only stay in the heat-resistant part of the floor, without to act directly on the plastic cover. this makes possible a functional separation between gas routing in the bottom part and providing one necessary for sound attenuation Volume in the lid.

The bottom part has two angled upwards from a bottom, opposite end walls, of which one from the inlet pipe and the other from the outlet pipe is penetrated and firmly connected to the respective tube. In a special training, these end walls each have a greater height than arranged in between, also angled from the floor, opposite each other arranged side walls, the height substantially is measured perpendicular to the ground. Because of this design is between the hot, gas-carrying pipes and the plastic cover a relatively large distance realizable, whereby the thermal load on the plastic cover reduced. At the same time there is less thermal stress Area of the side walls of the lid accordingly increases, which increases the weight advantage of the lid affects more.

Since the lid is made of plastic according to the invention is, the outer contour of the lid can be one advantageous training particularly easy to the respective Installation situation of the silencer in the exhaust line or be adapted to the vehicle. Through appropriate manufacturing processes, such as. Thermoforming or blow molding relatively complicated three-dimensional shapes for the Realize covers that do not or only with sheet steel a much greater effort are possible. Accordingly it is possible with the silencer according to the invention, to make better use of existing installation space to accommodate large ones Realize damping volumes.

Relieved with the help of the silencer according to the invention the connection of the exhaust system to the vehicle body as well as its assembly, as fasteners directly on can attack the stable bottom part of the silencer.

Other important features and advantages of the invention result itself from the dependent claims, from the drawings and from the associated description of the figures using the drawings.

Preferred embodiments of the invention are in the Drawings are shown in the description below explained in more detail.

Fig. 1

eine perspektivische Ansicht auf einen geschnittenen Schalldämpfer nach der Erfindung, wobei ein Deckel von einem Unterteil abgehoben ist,

Fig. 2

eine perspektivische Ansicht auf ein Unterteil des erfindungsgemäßen Schalldämpfers, jedoch bei einer anderen Ausführungsform,

Fig. 3

eine perspektivische Ansicht auf einen Schalldämpfer wie in Fig. 2, jedoch bei einer geschnittenen Darstellung und.mit vom Unterteil abgehobenem Deckel.

Each shows schematically

Fig. 1

2 shows a perspective view of a cut silencer according to the invention, a cover being lifted off a lower part,

Fig. 2

2 shows a perspective view of a lower part of the muffler according to the invention, but in another embodiment,

Fig. 3

a perspective view of a muffler as in Fig. 2, but in a sectional view and. with the cover lifted from the lower part.

1 shows a silencer according to the invention 1 a housing 2, which is constructed with two shells. The Silencer 1 is for installation in a not shown Exhaust system of an internal combustion engine, in particular one Motor vehicle provided. This housing 2 thus has a trough-shaped base part 3 and a matching, trough-shaped cover 4. The bottom part 3. has a bottom 5 on that of two opposite end walls 6 and 7 and two, extending between the end walls 6, 7, opposite side walls 8 bordered is. In Fig. 1 the cut is made so that only one of the side walls 8 is shown. In this way the bottom part 3 receives a self-supporting structure. The bottom part 3 is made of a metal, e.g. made of sheet steel. A deep-drawing process is preferred here the end walls 6, 7 and the side walls 8 from the bottom 5 be formed.

In the bottom part 3 a U-profile part 9 is inserted approximately in the middle, which is made of metal and its U-leg two Cross walls, namely a first cross wall 10 and a second Form transverse wall 11, which are in the bottom part 3 of each other spaced and extend parallel to the end walls 6 or 7. The U-profile part 9 is at its base 12 with the Bottom 5, e.g. by a welded connection, firmly connected. Likewise, the transverse walls 10 and 11 with the side walls 8, e.g. be firmly connected by welds. Through the Incorporation of these transverse walls 10 and 11 increases the rigidity and stability of the bottom part 3. The transverse walls 10 and 11 can also be installed as individual parts in the bottom part 3 his.

The silencer 1 also includes an inflow pipe 13, through which the hot exhaust gases and the sound to be damped in enter the housing 2. This inflow pipe 13 penetrates the first end wall 6 facing the viewer and both transverse walls 10 and 11 and ends with one only partially visible mouth end 14 in an inflow space 15. This Zuscrömraum 15 is laterally from the side walls 8, the second transverse wall 11 and the second facing away from the viewer End wall 7 limited. The inflow pipe 13 is with the first End wall 6 firmly connected, in particular welded or soldered. In addition, the inflow pipe 13 is supported on the transverse walls 10 and 11 in the radial direction, without one in the axial direction of the inflow pipe 13 effective fixation between the inflow tube 13 and the transverse walls 10 and 11 must be provided. Accordingly results then for the inflow pipe 13 in the transverse walls 10 and 11 a kind of sliding seat. This storage enables relative movements between the inflow pipe 13 and the transverse walls 10 and 11, which can occur due to thermal loads. Alternatively, the inflow pipe 13 can also be fixed to the transverse walls 10 and 11, wherein thermal expansion of the Inflow pipe 13 then by elastic deformation of the transverse walls 10,11 be included. Furthermore, the Muffler 1 has a discharge pipe 16 which is the second end wall 7 and the two transverse walls 11 and 10 penetrates and with a mouth end 17 opens into an outflow chamber 18. This Outflow chamber 18 is laterally through the side walls 8, the first End wall 3 and the first transverse wall 10 limited. That too Outflow pipe 16 is fixedly connected to the second end wall 7 and mounted axially displaceably in the transverse walls 10, 11 or firmly connected, in both cases a radial Support of the outflow pipe 16 on the transverse walls 10 and 11 is realized.

In the embodiment shown here, the pipes run 13 and 16 parallel to each other and parallel to the floor 5. Also the tubes 13 and 16 are arranged relatively close to the bottom 5. Furthermore, the mouth ends are 14 and 17, respectively aligned with the floor 5 to deal with the hot exhaust gases to target the heat-resistant floor 5. In particular, this arrangement enables the expulsion of Condensate, which is at the bottom 5, e.g. in winter, accumulate can.

The transverse walls 10 and 11 separate in the housing 2 between the Inflow space 15 and the outflow space 18 also an intermediate space 19 from. Furthermore, it is axially open on both sides Coupling tube 20 is provided, the two transverse walls 10 and 11 penetrates and thus a communicating connection between inflow space 15 and outflow space 18. To this In the inflow space 15 and in the outflow space 18 several cross-sectional jumps within the flow path of the exhaust gases trained in a sound transmission counteract the outflow pipe 16. The coupling tube 20 is also made of a heat-resistant metal and is preferably with at least one of the transverse walls 10 and 11 firmly connected. Thus, the coupling tube 20 also contributes Increase the rigidity of the bottom part 3.

In the embodiments shown here, only that is Coupling tube 20 perforated in the area of the space 19 designed. Embodiments are also possible in which alternatively or in addition to the coupling pipe 20, the inflow pipe 13 and / or the outflow pipe 16 in the region of the intermediate space 19 and / or the transverse walls 10 and / or 11 perforated are designed.

This coupling tube 20 is in the area of the intermediate space 19 designed perforated and accordingly has one Plurality of radial openings 21. The one in the individual Rooms 15, 18 and 19 can propagate sound appropriate measures are dampened. The achievable damping effect especially the frequencies to be attenuated are about sizing the volumes of each Rooms 15, 18, 19 can be influenced. The occurring in the exhaust system Sound waves require relatively large-volume rooms 15, 18, 19 for their damping. Accordingly, the housing needs 2 of the silencer 1 has a relatively large volume. This volume is provided by the cover 4. This Lid 4 is made according to the invention from a plastic. This is possible because all gas-carrying elements and areas of the silencer 1 essentially in Bottom part 3 are arranged or formed. The leadership the hot exhaust gases are specifically so that only the heat-resistant metal parts of the silencer 1, So bottom part 3, tube 13, 16, 20 and transverse walls 10, 11, directly be exposed to the hot exhaust gases. To this The purpose of the coupling tube 20 is also relatively close to the bottom 5 arranged and parallel to the inflow pipe 13 or to the outflow pipe 16 aligned.

It is also of particular importance that the End walls 6 and 7 with respect to a measured perpendicular to the floor 5 Height have a greater height than the side walls 8. This ensures that the hottest Set the silencer 1 a relatively large distance to cover 4. The end walls 6 and 7 are special can be cooled as far as possible by applying a headwind, that the attached cover 4 no critical temperatures is exposed. The less highly educated Side walls 8 allow the cover 4 to be enlarged this area to make the weight advantage of the lid 4 stronger to be able to exploit.

In the embodiment according to FIG. 1, the cover 4 is on lined on the inside with an inner lining 22. This inner lining 22 suitably consists of a sound absorbing and thermal insulating material, which on the one hand, the spreading in rooms 15, 18, 19 Absorbs sound and on the other hand overheats the Plastic lid 4 is prevented.

The inner lining 22 consists, for example, of a temperature-resistant felt on the inside of the cover 4 is glued or melted. Such one Felt can in particular be made of E-glass fibers or quartz glass fibers getting produced. Such a felt can both be needled or sewn filament as well as carpet-like, standing perpendicular to the respective contact surface Fibers with adhesive or connection on the back are made. In addition to their thermal insulation effect these felts also dampen the pressure pulsations within the respective room 15, 18, 19 by absorption.

In the embodiment shown in Fig. 1 extend the transverse walls 10 and 11 each from the bottom 5 to one Blanket 23 on the inside of the lid 4. In particular, can End edges 24 of the transverse walls 10 facing away from the base part 3 and 11 in corresponding receptacles in the cover 4 and / or in the inner panel 22 may be included. The same applies to the lateral edges of the transverse walls 10 and 11 that over the side walls 8 of the lower part 3 protrude. Important is here that the individual rooms 15,18,19 also within the Lid 4 are sufficiently sealed against each other to avoid hot leakage flows in the plastic cover 4.

In the embodiment shown here, both have Bottom part 3 and the lid 4 each have a collar 25 or 26, each formed all the way round and to each other are complementary. In the area of these frets 25, 26 can base part 3 and cover 4, for example by gluing and / or rivets and / or positive locking, e.g. through attached clinging C-profiles, firmly connected become. It is also possible to have one in the region of the frets 25 Tongue and groove connection to realize, in which the one collar contains a groove in which one formed on the other fret Spring or in the other formed as a spring collar is insertable. In addition, a form-fitting Locking and / or gluing may be provided. alternative or in addition, the plastic collar of the cover 4 melted onto the metal collar of the base part 3 or with this be welded, creating a material connection is achieved. If necessary, can be riveted in any case and / or screwed.

In the embodiment according to FIG. 1, the spaces 15 form 18, 19 each reflection chambers, which also by the Interior trim 22 are damped.

2 and 3 is in another embodiment between the bottom 5 of the lower part 3 and the ceiling 23 of the lid 4, an intermediate floor 27 is arranged acoustically permeable by means of a plurality of openings 28 is designed. In this embodiment, extend the transverse walls 10 and 11 from the floor 5 to this Intermediate floor 27 and form a support for this. The intermediate floor 27 can be in the region of the federal government 25 End walls 6, 7 and optionally also on the transverse walls 10 and 11 be attached. Alternatively, it is possible to use the mezzanine 27 to attach in or on the lid 4. The mezzanine 27 is preferably made of metal.

Through the intermediate floor 27 is in the lid 4 from the bottom part 3 facing away cavity 29 separated between the intermediate floor 27 and the ceiling 23 extends. expedient is this cavity 29 with a sound absorbing material 30 filled or filled in, that in the present example can be formed by a full body. As a sound absorbing Material is also suitable here for temperature resistance Felt of the above kind as well as one suitable, heat-resistant wool. The sound absorbing Material 30 is in the cavity by means of the intermediate floor 27 29 positioned such that entrainment of the possibly loose Materials, e.g. Felt or wool, with the exhaust gas prevented becomes. Form in the embodiment according to FIGS. 2 and 3 the rooms 15, 18, 19 reflection chambers, while with absorption material 30 filled cavity 29 an absorption chamber represents.

According to Fig. 2 3 fasteners on the bottom part 31 attack, which are here in the form of rods, which are welded to the bottom part 3, for example. With With the help of these fasteners 31, the bottom part 3 and thus the entire silencer 1 via damping means, e.g. Suspension rubbers on a vehicle body, not shown be attached. To this extent, conventional suspension methods are used, which makes the Handling and attachment of the equipped with the silencer 1 Exhaust system simplified.

2 and 3 is in the range of Side walls 8 in contrast to the embodiment according to FIG. 1 no covenant formed. The attachment of the lid 4 on Bottom part 3 is done here by gluing from the side Aprons 32, which are formed on the lid 4 and Side walls 8 overlap when the lid 4 on the bottom part 3 is attached. If necessary, can also be riveted and / or screwed.

As materials for the base part 3 are particularly suitable Wise single or multi-layer stainless steel sheets or aluminized Steel sheets. For the transverse walls 10 and 11 as well as for those used Pipes 13, 16 and 20 and optionally for the Intermediate floor 27 is particularly suitable for single-ply Steel or stainless steel sheets used for acoustic tuning can also be locally perforated.

Temperature-resistant, sprayable are suitable for the cover 4 Plastics, e.g. Polyphenylene sulfides, polyarsulfones, Polyether sulfones, polyether ether ketones, polyether ketone ketones, Polyimides, bismaleimides and cyanate esters.

To ensure relatively high rigidity values even at high temperatures To be able to have reinforcing fibers made of glass, aramid, ceramic or coal in the spray material come. It is also possible to use reinforcing fiber fabrics arrange in the injection mold and then with the respective Overmolding plastic. Instead of thermoplastics thermosets are also used, which are also expedient are fiber reinforced. For example, polyester, Epoxy, phenolic and melamine resins.

The following are suitable for producing the plastic cover 4 Manufacturing process: spraying in molds, blowing out Preforming, pulling in the soft state, inserting impregnated Fiber fabrics (prepregs) and heating in the mold, laminating of fiber laid in the form (rolling, spraying), the respective reaction is triggered with light or heat.

LIST OF REFERENCE NUMBERS

1

silencer

2

casing

3

the bottom part

4

cover

5

ground

6

first end wall

7

second end wall

8th

Side wall

9

Channel member

10

first transverse wall

11

second transverse wall

12

Base of 9

13

inflow pipe

14

Mouth end of 13

15

inflow

16

outflow pipe

17

Mouth end of 16

18

outflow

19

gap

20

coupling tube

21

radial opening of 20

22

Interior lining from 4

23

Blanket of 4

24

Top edge of 10.11

25

Bunch of 3

26

Bunch of 4

27

false floor

28

Opening in 27

29

Cavity in 4th

30

sound absorbing material

31

fastener

32

apron

Claims (11)

1. An exhaust muffler for an exhaust line of an internal combustion engine, in particular of a motor vehicle,

   having a pan-shaped self-supporting bottom part (3) made of metal having a bottom (5) enclosed by two opposing side walls (8) and two opposing end walls (6, 7) and including two transverse walls (10, 11) which are fixedly connected to the bottom (5) and/or to the side walls (8) and run essentially parallel to the end walls (6, 7),

   having an inflow pipe (13) which passes through the first end wall (6) and the two transverse walls (10, 11), is fixedly connected to the first end wall (6) and is supported radially on the two transverse walls (10, 11),

   having an outflow pipe (16) which passes through the second end wall (7) and the two transverse walls (10, 11), is fixedly connected to the second end wall (7) and is supported radially on the two transverse walls (10, 11),

   having a pan-shaped cover (4) made of plastic which seals the bottom part (3) airtight,

   whereby the transverse walls (10, 11) separate in the interior of the muffler (1) an inflow space (15) bordered by the second end wall (7) with the inflow pipe (13) opening into it, an outflow space (18) bordered by the first end wall (6) with the outflow pipe (16) opening into it and an intermediate space (19) bordered by the transverse walls (10, 11),

   whereby a coupling pipe (20) which is open on both ends passes through the two transverse walls (10, 11) and connects the inflow space (15) to the outflow space (18) so they communicate.
2. The muffler according to Claim 1, characterized in that regions of the muffler (1) through which the exhaust passes are arranged and/or formed essentially in the bottom part (3).
3. The muffler according to Claim 1 or 2, characterized in that the coupling pipe (20) is arranged near the bottom (5), at least essentially within the bottom part (3).
4. The muffler according to one of Claims 1 through 3, characterized in that the cover (4) is lined with an inside lining (22) on'its inside, said lining consisting of a sound-absorbent and/or thermally insulating material.
5. The muffler according to one of Claims 1 through 4, characterized in that the end walls (6, 7) of the bottom part (3) each have a greater height than the side walls (8) of the bottom part (3), where the height is measured essentially at a right angle to the bottom (5) of the bottom part (3).
6. The muffler according to one of Claims 1 through 5, characterized in that each transverse wall (10, 11) extends from the bottom (5) up to a roof (23) of the cover (24).
7. The muffler according to one of Claims 1 through 5, characterized in that an acoustically permeable partition (27) is provided in the interior of the muffler (1) between the bottom (5) and a roof (23) of the cover (4), each transverse wall (10, 11) extending from the bottom (5) to the partition (27) whereby the partition (27) separates a hollow space (29) in the cover (4) which faces away from the bottom part (3) and is filled and/or packed with a sound-absorbing material (30).
8. The muffler according to one of Claims 1 through 7, characterized in that the inflow pipe (13) and the outflow pipe (16) and - if present - the coupling pipe (20) run essentially parallel to the bottom (5).
9. The muffler according to one of Claims 1 through 8, characterized in that the outside contour of the cover (4) is adapted to the respective installation situation of the muffler (1).
10. The muffler according to one of Claims 1 through 9, characterized in that the muffler (1) is mounted with mounting means (31) on a vehicle body, whereby the mounting means (31) act on the muffler side only on the bottom part (3).
11. The muffler according to one of Claims 1 through 10, characterized in that the cover (4) is connected to the bottom part (3) by at least one of the following measures:

    by gluing,

    by at least one C-shaped clamp placed on flange rims (25, 26) that protrude outward from the cover (4) and the bottom part (3),

    by a tongue-and-groove connection,

    by a snap connection,

    by melting the plastic cover (4) onto the metal bottom part (3),

    by welding the plastic cover (4) onto the metal bottom part (3),

    by riveting,

    by screw connection.

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