WO1999025967A1

WO1999025967A1 - Metal pipe

Info

Publication number: WO1999025967A1
Application number: PCT/EP1998/007272
Authority: WO
Inventors: Alfred Steck
Original assignee: Zeuna-Stärker GmbH & Co. KG
Priority date: 1997-11-18
Filing date: 1998-11-13
Publication date: 1999-05-27
Also published as: AU1338099A; DE19750959A1

Abstract

The invention relates to a metal pipe, especially an exhaust gas pipe for the exhaust system in a motor vehicle. The inventive pipe has a wall (2) and one end-side reinforcement (3). Said reinforcement forms a single piece with the wall (2) of the pipe, consisting of at least one crumpled section (4) resting against said wall (2).

Description

Metallic pipe

The present invention relates to a metallic pipe, in particular an exhaust pipe for the exhaust system of a motor vehicle, with a pipe wall and a reinforcement provided at the end and abutting the pipe wall.

Metallic pipes are subject to relatively high mechanical loads in a large number of applications. This applies in particular to the exhaust pipes of the exhaust systems of motor vehicles, in which both oscillations and vibrations of the drive motor and shocks due to bumps in the road place a great strain on the pipes in question. The loads concentrate on the pipe ends at which the pipe in question is connected to the adjacent components of the exhaust system.

Against this background, reinforcement is often provided at the end of metallic pipes, in particular exhaust pipes for the exhaust system of motor vehicles. This usually consists of a support sleeve which is pushed over the end of the pipe and welded to the pipe wall in the intended position.

A disadvantage of such a generic, reinforced metallic tube is the effort associated with its production, because the support sleeves must be manufactured, managed, fitted and welded separately, with the fact that the support sleeve only develops its optimal effect if its inside diameter is exact is matched to the outside diameter of the pipe wall. The object on which the present invention is based is derived from this and consists in reducing the costs associated with the production of a generic tube.

According to the present invention, this object is achieved in that the reinforcement is in one piece with the tube wall, in that it consists of at least one turned-up tube section lying against the tube wall. According to the invention, the pipe wall at the end of the pipe merges into the reinforcement under a 180 ° inversion. Or in other words, the reinforcement is formed from an upturned or turned-up tube section which previously protrudes beyond the later end of the tube, "turning inside out" in this sense meaning that the inner surface of the tube section used to form the reinforcement after the "turning upside down" points outwards and vice versa. A number of serious advantages are associated with the inventive design of a metallic tube with reinforcement provided at the end. In particular, there is no need to manufacture, manage and handle an insulated support sleeve, because the reinforcement - depending on requirements - is made from a section of the tube itself. This results in outstanding flexibility with regard to the design of the reinforcement; Because this can - depending on the requirements - be longer or shorter, two or three layers (see below).

A preferred development of the invention is characterized in that the reinforcement rests on the inside of the tube wall. In this case it is the reinforcement Kung forming tube section turned inside out, and the former inner surface of that tube section faces outwards and lies against the inner surface of the tube wall. The reinforcement can be formed in one layer. According to a preferred development of the invention, however, it is double-layered and consists of a rolled-up first reinforcement layer lying on the inside of the tube wall and a not turned-up second reinforcement layer lying on the inside of the first reinforcement layer. Such a double-layer structure of the reinforcement is reflected in a particularly efficient stiffening of the corresponding pipe end. In addition, there are advantages in terms of production technology in that the outer region of the tube section serving to form the reinforcement is not turned inside out, but rather without being turned inside out, forms the inner, second reinforcing layer solely by axial displacement.

If, according to the development of the invention explained above, the reinforcement lies against the inside of the tube wall, then according to a further particularly preferred embodiment the tube wall can be widened in the region of the reinforcement. Such a widening of the tube wall enables the tube in the area of the reinforcement to have the same clear width as in the non-reinforced area. The tube wall can be expanded in the area in which the reinforcement will later lie before the tube section forming the reinforcement is turned inside out. It is also possible to expand the tube wall (together with the reinforcement) after the reinforcement has been produced by turning the corresponding tube section inside out. Insofar as pipes according to the invention have been explained above, in which the reinforcement lies on the inside of the pipe wall, this represents a preferred, but not the only possible embodiment of the invention. Rather, it is also considered that the reinforcement lies on the outside of the pipe wall. This applies in particular to a double-layer reinforcement, the above explanations correspondingly applying in a corresponding manner. Instead of the tube wall, the area of the tube section forming the subsequent reinforcement, which forms the second reinforcement layer, lies on the outside of the first reinforcement layer, which in turn lies on the outside of the tube wall - and this before the reinforcement is formed.

The metallic tube according to the invention can have a flange at the end, in that a flange plate is welded to the tube wall and the reinforcement. However, the advantages of the present invention particularly come into play when a flange provided at the end is designed as a common widening of the tube wall and the reinforcement. In this case, the reinforcement and the flange can be produced particularly inexpensively and precisely in a single two-stage operation in the same machine.

The invention is explained in more detail below with reference to exemplary embodiments shown in the drawing. Show 1 to 4 different embodiments of a

Pipe without flange, each in longitudinal section,

5 and 6 two embodiments of a

Pipe having a flange according to the invention, likewise in longitudinal section,

7 shows four steps in the manufacture of a reinforced tube according to FIG. 1 and

Fig. 8 five steps in the manufacture of a reinforced tube with flange.

In each of the exemplary embodiments shown in FIGS. 1 to 6, the tube 1 in each case comprises a tube wall 2 and a reinforcement 3. The reinforcement 3 is in one piece with the tube wall 2. It is formed by reshaping a tube section initially projecting beyond the later tube end , wherein the reinforcement consists of at least one rolled-up pipe section 4 lying against the pipe wall 2.

In the case of Fig. 1, the reinforcement 3 is constructed in one layer. In other words, the reinforcement 3 of the tube consists exclusively of the above-mentioned upturned tube section 4. The reinforcement 3 is arranged on the inside, ie the tube section 4 lies against the inside of the tube wall 2. Before turning the pipe section 4 upside down, its current inner surface pointed outwards; and the outer surface of the rolled-up pipe section 4, which was in contact with the inner surface of the pipe wall 2, formed its inner surface before the pipe section 4 was turned inside out. The pipe shown in FIG. 2 differs from that according to FIG. 1 in that the pipe wall 2 is expanded cylindrically in the area of the reinforcement 3. To produce the tube shown in FIG. 2, the tube wall 2 can be expanded cylindrically in the area in question before the tube section 4 is turned inside out; in the same way, tube wall 2 and tube portion 4 which has already been turned inside out (cf. FIG. 1) can be cylindrically expanded in order to produce the tube shown in FIG. 2. Regardless of the type of production, it follows that the tube in the area of the reinforcement 3 has the same inside width as outside the reinforced area, which is often preferred for fluidic reasons.

Fig. 3 illustrates a pipe according to the invention, the reinforcement of which is constructed in two layers. The reinforcement 3 comprises a first, turned-up reinforcement layer 4 and a second, not turned-up reinforcement layer 5. The first reinforcement layer 4 lies against the inside of the tube wall 2, while the second reinforcement layer 5 lies against the inside of the first reinforcement layer 4. According to the tube shown in FIG. 2, the tube wall 2 is expanded cylindrically in the area of the reinforcement 3. The second reinforcement layer 5, which has been produced without having been turned upside down, by axially displacing the corresponding pipe section, has only a slightly smaller clear width than the pipe 1 outside the reinforcement.

FIG. 4 illustrates a pipe according to the invention with an external reinforcement 3. This is in turn constructed in two layers; it includes a rolled-up, first reinforcement layer 6 lying on the outside of the tube wall 2 and a second reinforcement layer 7 which is not turned inside out and which lies on the outside of the first reinforcement layer 6 corresponding pipe section and thereby turning inside out the pipe section forming the later first reinforcement layer 6, the double-layer reinforcement is formed.

5 shows a tube 1 which has a flange 8 at the end. This tube emerged from the tube according to FIG. 4 in that the tube wall 2 together with the two layers 6 and 7 of the reinforcement 3 was spherically widened at the end. In other words, the flange 8 is formed as a common widening 9 of the tube wall 2 and the reinforcement 3 in a partial end region of the reinforcement 3.

FIG. 6 shows a tube 1 with a flange 8, which has been formed by deformation from the tube illustrated in FIG. 2. Here, the conical flange 8 is designed as a common widening 9 of the tube wall 2 and the reinforcement 3 in an end portion of the reinforcement.

FIG. 7 illustrates, in four steps, a preferred way of producing a single-layer internally reinforced tube, as shown in FIG. 1 and described above. First (see step a), the pipe end is of a length L1, which is essentially the axial length L2 of that pipe section 4 corresponds to, which forms the reinforcement 3 in the finished tube (see step d), slightly retracted. In the case shown, the drawn-in end pipe section has a diameter four times the value of the wall thickness S smaller than the pipe in the remaining area. Of course, this is not mandatory; for example, the drawn-in end pipe section could also have a diameter that is only three times the value of the wall thickness S less than the diameter of the pipe outside the drawn-in pipe section.

According to steps b and c, the drawn-in pipe section is gradually pushed into the not drawn-in pipe section. A simple pressing tool, for example a pressure plate, is suitable for this.

A tool 10, which essentially consists of a stepped mandrel, serves to further roll up the drawn-in tube section to form the single-layer reinforcement. If the tool 10 is inserted into the partially formed tube, as shown in step c of FIG. 7 (arrow A), the retracted tube section is pushed in further through the step 11 of the tool 10 and completely turned inside out, as shown in FIG Step d of Fig. 7 is shown.

FIG. 7 is also suitable for illustrating the production of the tubes according to FIGS. 3 and 6. To produce the tube according to FIG. 3, the method illustrated in FIG. 7 has to be terminated in step c. The expansion of the pipe in the area of the reinforcement rt s ^> M 03 03 ^ o Qß 03 ö 3 Qß su N s: Hl 3 2: <er ≤ er er X d φ μ- φ • d SU 0 SU μ- SD μ- SD dd Φ 0 = μ- φ φ Φ Φ Hj Φ SD μ- d er SD = er Qß Ω 03 rt 03 Hi CQ Hj Hj rt μ- HJ rt μ- SU μ- d

• d rt CQ Φ rt rt Hi 0 er CQ pr 3 03 03 Hj rt Ω d rt φ Ω d Φ Φ Φ H {μ- ^ μ- Φ Φ N μ- d rt rt Φ Φ tr CQ

Φ Hj he Hj d Ω <! dd sS μ- Φ CQ d SD- "Hl Hi rr H- ¹ 1 μ- φ HD tr 0 SD Φ Ω d Φ rt ß Hj Hl φ to <! φ u φ d ^ d ^ μ- tr CQ d Φ SD Φ 0 ≤ μ- sS

Φ Φ er Φ> 03 μ- 03 μ- rt 03 Hj 03 0 d er Φ Ω μ-

Hj Hj Φ Hj 0 CQ D ß CQ Ω CQ Φ Qß er 0 D Φ Hj tr φ

Φ Hi d Hi Φ _^ - _^ SU Φ • tr • rt SU N & Hj μ- CQ Φ d Di N μ- o CQ 0 03 co CΛ 3 CQ 0 ω 0 dd φ Φ sS

Ω Hi Di φ Hi rt Ω l_l. 00 Φ CTι B Ω Ω μ- σ d μ- Φ tr 3 Φ 03 3 SU er CQ φ d 03 PO tr er ^ 0 to Φ • rt μ- rt 03 rt d 0 Hj Φ d <: rt Qß 0 0 < d Φ μ- 0 Hj μ- rt

0 • SD d Ω μ- 3 μ- Φ 03 SU tr o μ- d <Q to er Φ CQ φ

0 PO d CQ er r SU: CQ Hi rt Hi ß Hj H- ¹ rt Φ • φ Hj μ- H Φ Hj

Hj 0 Ω rt rt C> Φ SD Φ CQ SU Φ rt d rt su rt rt Hj d er er φ dd tr Φ CΛ d 03 I Hi he CQ Φ 0 φ H {rt μ- sS SU CD 03 rt CQ D rt H t- ¹ SD 03 HJ> er μ- Φ Φ d μ- - Ω IQ Ω • rt μ- Φ SD = t μ- Qß Ω Ω Qß d Φ d 0 d Φ H {tr Φ er Φ ddd SD er er SU SU Hi d

3 Hi Qß to CQ D Qß H {3 SD 03 Di SD μ- Hi rt d Hj rt sS

SD rt Φ Φ • SU μ- SD: d M φ SU μ- 0 φ CQ • μ- CQ μ- φ Φ

Φ 03 Hi rt CQ rr IΛ> rt μ- 3 CQ Hi d φ rt Φ μ- Hj μ- Φ d ö rt μ- Φ 0 rt Φ * • CQ rt rt

Qß,. μ- μ- po ^ Ω φ d su rt Φ Φ pr 0 SD =

0 tr CO Ω> d Φ 0 er μ- er Φ 3 Q- in d Φ 03 CQ SU: 0 d

Hj su Ω tr Φ 03 tr CQ rt d Φ O Q rt 3 CQ rt

Ω Hi er d Φ Hj d • Φ Qß φ Hj 3 φ <! - Φ Φ er rt Hj ≤ Hl SD 03 μ-? R ≤ Qß rt 0 Qß Hi

Φ μ- μ- 0 = Td d Ω -j <Φ d <Hj μ- Φ Φ Hj Φ Φ rt

Hi rt Hi Hi SU d tr Φ μ- N φ φ Hj d μ- D Hj

3 rt ß 3 rt μ- Hj rt μ- H {3 Di rt 21 Qß d μ- sS

Holy 2! φ μ- rt Φ Qß 3 Hl μ- CQ CQ O Φ Φ Φ φ φ <d

0 C er CQ Φ Hj Φ SD CQ Φ rt Φ er rt Hj 3 ω Φ HJ

Hj μ- Ω Φ φ 3 sS er d SU: Φ -r Hj D

3 03 μ- d μ-> Φ Hi <! Hj d μ- μ- NM d Z 03 Φ d φ er 3 03 0 M ∞ Φ Φ X 3 Q φ μ- Hl 0 rt d μ- ^ rt 03 μ- Φ d HJ Hj 0 Di rt dd ≤ Hj SD: 1

CQ sS 03 sS er dd 03 er 0 Φ M * CQ X Φ Di Hj μ- Φ SU Hi μ- N rt d rt Φ CQ Hj μ- Hf μ- Φ SU er HJ φ μ- dd = μ- H- ¹ d SU = μ- d Φ μ> Φ rt 0 d

Φ D- - rt CQ Hj i φ μ- rt Hj rt X <03 μ- 0 3 Φ 0 CQ

Φ Ω the Ω Φ PT 03 φ φ Ω d * d 0 the CQ Ω

SD Qß d Hi er Qß d Φ er Hj rt 03 CQ Hj tr φ Φ CQ Φ er

03 Φ μ- Φ φ μ- CQ d φ CQ Φ Ω Φ CQ μ- d H- "d Φ H rt Hi Ω d CQ φ d Ω er H- ¹ rt φ μ- d D Hi μ- μ- φ er Φ D tr to Hj Hi SD = er φ Φ SU d φ rt SU rt <J μ- Φ S φ 0 μ- 0 = Hj Φ φ D 03 CQ

• d 0 d CQ μ- tr rt Hj d CQ Qß φ Φ φ

Hi Hi φ D- Hj rt 3 0 Φ μ- Hi 03 d

CQ CQ Hj φ φ μ- 0 φ D φ Φ μ- rt CQ CQ Φ 03 d 03

Claims

Expectations

Metallic pipe, in particular exhaust pipe for the exhaust system of a motor vehicle, with a pipe wall (2) and a reinforcement (3) provided at the end, characterized in that the reinforcement (3) is in one piece with the pipe wall (2) in that it is made of at least one turned inside out , there is a pipe section (4, 6) resting on the pipe wall (2).

Metallic pipe according to claim 1, characterized in that the reinforcement (3) rests on the inside of the pipe wall (2).

Metallic pipe according to claim 2, that a double layer with the pipe wall

(2) one-piece reinforcement

(3) is provided, which consists of a rolled-up first reinforcing layer (4) resting on the inside of the pipe wall (2) and a non-turned-up first reinforcing layer on the inside of the first reinforcing layer

(4) adjacent second reinforcement layer (5).

Metallic pipe according to one of claims 2 or

3, characterized in that the pipe wall (2) is expanded in the area of the reinforcement (3).

5. Metallic pipe according to one of claims 1 to 4, characterized in that a flange (8) is provided at the end.

6. Metallic pipe according to claim 5, characterized in that the flange comprises a flange plate welded to the pipe wall and the reinforcement.

7. Metallic pipe according to claim 5, characterized in that the flange (8) is designed as a common expansion (9) of the pipe wall (2) and the reinforcement (3).