CN215057659U

CN215057659U - Exhaust muffler and vehicle having the same

Info

Publication number: CN215057659U
Application number: CN202121321757.2U
Authority: CN
Inventors: C·法依纳
Original assignee: Faurecia Emissions Control Technologies Germany GmbH
Current assignee: Faurecia Emissions Control Technologies Germany GmbH
Priority date: 2020-06-16
Filing date: 2021-06-15
Publication date: 2021-12-07
Anticipated expiration: 2031-06-15
Also published as: DE102020115859A1

Abstract

An exhaust muffler comprises two tubes (14, 16) inserted into each other, wherein an inner tube (16) is inserted into an outer tube. The two tubes are deformed from the inside in the overlapping region (22) to form two bulges (26, 28, 30, 34) by means of which the tubes (14, 16) are mechanically coupled to each other. The resulting flared end (32) of the inner tube (16) is located within the bulb (28) of the outer tube to prevent flow noise. Furthermore, a vehicle with such an exhaust muffler is proposed.

Description

Exhaust muffler and vehicle having the same

Technical Field

The invention relates to an exhaust gas muffler having an outer pipe which guides the exhaust gas and an inner pipe which guides the exhaust gas and which is pushed into the outer pipe on the end side, wherein the pushed-in section defines an overlap region of the pipes, and the pipes are jointly plastically deformed from the inside to the outside in the overlap region with the formation of two axially spaced elevations and are thereby connected to one another in a form-fitting manner.

Background

In exhaust mufflers, it is important that the tubes inserted into one another remain reliably and fixedly connected to one another despite vibrations and thermal expansions occurring during operation. In addition to the just mentioned mechanical connection by common plastic deformation of the tubes, the tubes can of course be connected to one another by welding or soldering.

In addition to mechanical fatigue strength, gas tightness is also an important property of the connection.

SUMMERY OF THE UTILITY MODEL

The task of the utility model is to additionally also be able to realize better gas flow in the interior of the gas guide formed by the pipe connection.

To this end, the invention proposes an exhaust gas muffler having an outer pipe which guides the exhaust gas and an inner pipe which guides the exhaust gas and which is inserted into the outer pipe at the end, wherein the inserted sections delimit an overlap region of the pipes and the pipes are jointly plastically deformed from the inside to the outside in the overlap region with the formation of two axially spaced elevations, thereby connecting them in a form-fitting manner to one another, wherein the end of the inner pipe located in the overlap region is flared outward and is located completely in the elevation of the outer pipe.

In the prior art, the end of the inner tube, which is spaced apart from the bulge located adjacent thereto, is always outside the bulge of the outer tube, thereby reducing the flow cross section. Furthermore, when exhaust gas flows from the outer pipe into the inner pipe, the insertion end of the inner pipe is subjected to frontal inflow, so that turbulence and noise may occur here. These disadvantages are avoided by the present invention. The insertion end of the inner tube is hidden in the bulge of the outer tube, which is formed when the two tubes are deformed (molded).

For example, when viewed in cross section, the flared, inserted end of the inner tube transitions from the cylindrical intermediate section between the bulges with a bend (Kr hummung) instead of a bend (kink) into the end section, which jointly comprises the flared (flared) end. The end section thus starts with a flared end and still extends out a certain portion along the inner tube in the overlap region. The flow guidance is further improved by the bend, since in the case of a flow from the outer pipe into the inner pipe, the bent section is subjected to an inflow, which is located at least partially outside the bulge.

In the end section, according to a variant of a first embodiment of the invention, the inner tube extends cylindrically, i.e. it has the same cross section over a certain axial length. By means of this cylindrical section, the positional tolerances of the inner and outer tube can be compensated.

The end section can be located completely in the bulge of the outer tube and thus be a flow shield: (

Concealed from incoming flow).

Preferably, the inner cross-section of the inner tube in the region of the end section (within manufacturing tolerances) is equal to the cross-section of the outer tube in the non-deformed section of the end section upstream of the bulge. This also improves the flow guidance, since there are no cross-sectional discontinuities.

Between the axially spaced elevations, the outer tube can have a cylindrical middle section, in particular without plastic deformation (deformation) in this section for connecting the tubes, as in the inner tube. The arrangement (seating) of the tubes is additionally improved thereby.

It is also advantageous for the arrangement (seating) of the tubes relative to one another that the outer tube is cylindrical at its borders on and between the elevations and has the same geometry there, i.e. the geometry between the elevations corresponds to the geometry outside the elevations. The same may additionally or alternatively be applied to the inner tube.

Since the length of the tubes is provided with tolerances and it is important that the finished product reaches the correct axial length, the overlap area of the different exhaust mufflers may vary slightly. This change is borne by the overlap area because, for example, a longer inner tube will push more into the outer tube than a shorter inner tube. In order to enable this to occur without loss of aerodynamics, according to one variant of the invention, provision is made for the ridge which receives the insertion end of the inner tube to be longer in the axial direction than the axially spaced ridges. By the increased length of the bulge, it is possible to compensate for the length difference, since the inner tube always ends in a bulge which is longer in the axial direction and is received there. For this purpose, it is further advantageous if the bulge, in which the pushed-in end of the inner tube is received, is cylindrical between its two ends.

For ease of manufacture, the protuberances axially spaced from the protuberances receiving the ends of the inner tube may be arcuate in cross-section (may be arcuate in cross-section).

Preferably, the two elevations are circumferentially closed around. Alternatively, however, the bulge which does not receive the end of the inner tube may also only partially (in sections) surround it.

In order to facilitate an optimized connection of the tubes, it is also advantageous for the gas tightness that the tubes bear against one another over their entire surface (in full-surface contact) in the region of the elevations and between the elevations.

In order to further stabilize the pipe connection between the elevations of the outer pipe, the circumferential edge of the holding element can be clamped in the axial direction and/or in the radial direction. When the two tubes are deformed from the inside, this edge is also deformed together.

The retaining element can be, for example, a ring, in particular a sheet metal ring, but also a connection of the wall of the exhaust muffler.

In order to improve the sound damping, the outer tube can be microperforated outside and additionally also in the overlap region and has a cross section of 0.02mm²To 0.2mm²Wherein the microperforation to be achieved is provided with a degree of perforation of at least 2%, i.e. in the region of the microperforations the total area of the openings amounts to at least 2% and preferably at most 7% of the total area of the tube. Although no gas flows out of the microperforations in the overlap region, the microperforations promote flexibility of the outer tube in the overlap region and provide easier modification (forming).

As already mentioned, it is advantageous that the flared (flared) end of the inner tube is the upstream end of the inner tube.

Furthermore, the invention relates to a vehicle with an exhaust muffler according to the invention.

The features described above in relation to the exhaust muffler also apply to the method.

Drawings

Other features and advantages of the present invention can be obtained from the following description and the accompanying drawings referred to below. Shown in the attached drawings:

figure 1 is a longitudinal section of a variant of the exhaust muffler according to the invention;

FIG. 2 is an enlarged longitudinal section through the connection of the inner tube with the outer tube shown in FIG. 1; and

fig. 3 is an enlarged longitudinal section through the connection of the inner and outer tubes present in fig. 1, together with the tool, at other tube lengths.

Detailed Description

Fig. 1 shows an exhaust gas muffler having a housing 10 with a circumferential wall (circumferential wall). An end wall 12 is provided in the housing 10, however, it can alternatively also serve as an outer wall of the outer housing 0 and thus together close the housing. Both variants can be used in the present invention.

In the outer casing 10, two pipes, a larger outer pipe 14 and a smaller inner pipe 16, which guide the exhaust gas, are inserted into each other. The

pipes

14, 16 may conduct the exhaust gas through the housing, or may conduct the exhaust gas only in certain sections (in sections) of the housing, for example only in the housing, or may conduct the exhaust gas into the housing and/or may conduct the exhaust gas out of the housing. All these variants are conceivable.

The two

tubes

14, 16 are connected to one another in a form-fitting manner, as will be shown in more detail below with reference to fig. 2 and 3. Furthermore, they are likewise fastened with a form fit at the end wall 12, so that the end wall 12 supports or even completely holds the

tubes

14, 16. Of course, additional fasteners may be provided for the tube.

It can be seen in fig. 2 that the outer tube 14 is significantly thinner than the inner tube 16, but this is only an option.

The outer tube 14 is designed and constructed for sound damping by means of a microperforation 18, here by means of a (thin) elongated slit having 0.2mm²And greater than 0.02mm²(from 0.02mm²To 0.2mm²) The maximum cross-sectional area of (a). In the perforated section 20 of the tube 14, i.e. the section starting from the first microperforation at the axial end up to the last microperforation in the axial direction, there is a perforation of at least 2% and at most 7%.

As the inner tube 16 is partially (in sections) inserted into the outer tube 14, an overlapping region 22 of tubes is created.

The end wall 12 has an axially extending junction 24, the junction 24 also being located in the overlap region 22 and defining an opening for receiving the two

tubes

14, 16.

The two

tubes

14, 16 are mechanically connected to each other by an internal deformation process. More precisely, after the two

tubes

14, 16 have been inserted into one another, a first bulge 26 and a second bulge 28 are formed in the outer tube 14 by a modification of the two tubes, wherein the inner tube 16 contains a respective bulge 30 formed complementary to the bulge 26.

The end 32 of the inner tube, which is located in the transition region 22 and delimits the overlap region, also delimits a bulge 34 in the inner tube 16, which bulge 34, in contrast to the bulge 30, no longer extends radially inward towards the end 32, but connects the tube 16 as a flared end 32.

At the second tube 16, a cylindrical end section 36 adjoins the end 32, the end section 36 largely defining the bulge 34. The end section 36 is formed by the tube 16 widening (flaring) from its original smaller shape. This initial shape is visible between the

bulges

30, 34 and below the bulge 30 with reference to fig. 2, in which sections the tube 16 is cylindrical and which sections also have the same cross-sectional shape, in particular a circular cross-section.

This means that between the

elevations

30, 34, the inner tube 16 and the outer tube have so-called

intermediate sections

38, 39, wherein the

tubes

14, 16 lie flat against each other in the intermediate sections 38, 39 (face-to-face contact). Furthermore, this also applies in the region of the

elevations

26, 30 and 28, 34.

This planar abutment is supported by the

tubes

14, 16 optionally being inserted into one another with a slight clearance fit when they are not deformed.

As can be seen in fig. 2, the second tube 14 also has a microperforated portion 18 in the overlap region 22.

The

elevations

26, 30 extend arcuately (arcuately) in cross section. The bulge 28 is significantly longer in the axial direction than the bulge 26, and the end section 36 is also longer than the bulge 30 of the inner tube 16.

In the illustrated, alternative embodiment, the outer tube 14 is an upstream tube, and thus, the end 32 is also an upstream end of the inner tube 16.

The flow guidance of the exhaust gas is achieved with low swirl (little swirl) in that the end 32 located in the overlap region 22, and even the entire bulge 34 of the inner tube 16 (i.e. the end section 36), is located within the bulge 28 of the outer tube 14. In other words, the internal cross section of the tube 14 upstream of the bulge 28 is smaller than or equal to the internal diameter of the inner tube 16 in the region of the end 32 and the following end section 36, which is preferably cylindrical. In this region, there is thus no direct inflow of the end face of the end 32.

To further optimize the flow, the end section 36 transitions with a bend 40 into an intermediate section 38, wherein the intermediate section 38 has a smaller cross section than the inner cross section of the tube 14 upstream of the bulge 28.

The

elevations

26, 28 and 30, 34 are circumferentially closed around.

During the manufacture of

ridges

28, 34, joint 24 is also deformed slightly radially outward so that there is radial clamping. Coupling portion 24 is preferably (and should not be construed as limiting) axially shorter than intermediate section 38. However, the coupling 24 abuts against the downstream end of the bulge 28 in the region of the bend. The joint 24 thus forms a holder together with the end wall 12, and the joint 24 itself forms a surrounding edge of the holder.

By making the bulge 28 receiving the end 32 of the inner tube 16 relatively long, positional tolerances of the inner tube 16 and the outer tube 14 can be compensated for by the bulge, as can be seen from fig. 3.

In fig. 2, the outer tube 14 and/or the inner tube 16 are longer than the corresponding tubes in fig. 3, so that the overlap region 22 in fig. 3 is smaller than in the case of the

long tubes

14, 16 in fig. 2. However, the end 32 is still located completely within the ridge 28 of the outer tube 14 shown in FIG. 3. It is still possible to work with the same tool to connect the

tubes

14, 16 to each other. As can also be seen in fig. 3, link 24 is longer than link 24 in fig. 2, so that it extends over the entire intermediate section 38.

The exhaust muffler is formed by first inserting the inner pipe 16 axially into the outer pipe 14 in the end side, forming the overlap region 22.

A modified tool 50, shown symbolically in fig. 3, is then inserted into the inner tube 16 and thus also into the outer tube 14. The modification tool 50 may, for example, have one or more rollers 52 seated on an axis or shaft 56. The

elevations

26, 30 and 28, 34 are then produced from the inside by means of the roller or

rollers

52, 54 and the pairs of

elevations

26 and 30 and 28 and 34 are carried out simultaneously in each case. If a tool with two

rollers

52, 54 is present, all ridges can also be produced simultaneously. Further, as described above, the coupling portion 24 is also deformed (deformed).

Instead of the end wall 12, the coupling 24 can also be provided separately, i.e. as a circumferentially closed retaining ring, which still supports the connection of the

tubes

14, 16.

The

tubes

14, 16 also need not both extend completely within or separately from the housing 10, but they may themselves form the housing. The microperforated portion 18 also functions as a sound damper without an outer shell surrounding the microperforated tube 14. In this case, the pipe 14 constitutes a boundary with the surroundings of the vehicle provided with the exhaust muffler.

Claims

1. Exhaust gas muffler having an outer pipe (14) which conducts exhaust gas and an inner pipe (16) which is pushed into the outer pipe (14) at the end side and conducts exhaust gas, wherein the pushed-in sections define an overlap region (22) of the pipes (14, 16), and the pipes (14, 16) are plastically deformed from the inside to the outside in the overlap region (22) while forming two elevations (26, 28, 30, 34) which are spaced apart axially and are thereby connected to one another in a form-fitting manner, characterized in that the end (32) of the inner pipe (16) in the overlap region flares outward and is located completely in one of the elevations (28) of the outer pipe (14).

2. The exhaust muffler of claim 1, wherein the flared end (32) of the inner pipe (16) transitions, as viewed in cross-section, from a cylindrical middle section (38) between the ridges (30, 34) into a bend (40) in an end section (36) that includes the flared end (32).

3. The exhaust muffler of claim 2, characterized in that the inner pipe (16) is cylindrical in the end section (36).

4. An exhaust muffler according to claim 2 or 3, characterized in that the end section (36) is located completely in the bulge (28) of the outer pipe (14).

5. An exhaust muffler according to any one of the preceding claims, characterized in that the outer pipe (14) has a cylindrical intermediate section (38) between the axially spaced elevations (26, 28).

6. An exhaust muffler according to any one of the preceding claims wherein the outer pipe (14) is cylindrical adjacent to and between the ridges (26, 28) thereof and has the same geometry in those regions, and/or the inner pipe (16) is cylindrical adjacent to and between ridges (30) separated from the flared end (32) and has the same geometry in those regions.

7. An exhaust muffler according to any one of the preceding claims wherein the hump (28) receiving the flared end (32) is longer in the axial direction than the axially spaced humps (26).

8. An exhaust muffler according to any one of the preceding claims wherein the protuberances (26, 30) spaced from the flared end (32) extend in an arcuate shape in cross-section in the inner and outer tubes (16, 14).

9. An exhaust muffler according to any one of the preceding claims, characterized in that the elevations (26, 28, 30, 34) surround circumferentially closed.

10. An exhaust muffler according to any one of the preceding claims, characterized in that the pipes (14, 16) bear against one another over their entire surface in the region of the elevations (26, 28, 30, 34) and in the region between the elevations.

11. An exhaust muffler according to any one of the preceding claims, characterized in that the circumferential edge of the holder is clamped axially and/or radially between the bulges (26, 28) of the outer pipe (14) and is deformed together.

12. An exhaust muffler according to any one of the preceding claims, characterized in that the outer pipe (14) is microperforated outside the overlap region (22) and in the overlap region (22), having an opening with a diameter of between 0.02 and 0.2mm²And a perforation of at least 2% and in particular at most 7%.

13. An exhaust muffler according to any one of the preceding claims, characterized in that the flared end portion (32) is an upstream end portion of the inner pipe (16).

14. A vehicle having an exhaust muffler according to any one of claims 1 to 13.