Title:
SHEET METAL PART, IN PARTICULAR OF AN EXHAUST GAS SYSTEM
Kind Code:
A1


Abstract:
The present invention relates to a sheet metal component (1), in particular of an exhaust system, having a body (2) comprising at least two shells (3, 4), having at least one pipe (5), wherein at least two shells (3, 4) are joined together along butt edges (8, 9) that are in contact, wherein at least two shells (3, 4) form a tubular connecting area (10) in contact with the pipe (5) on the outside, into which the butt edges (8, 9) of the shells (3, 4) that have been joined together extend, wherein the pipe (5) is joined to these shells (3, 4) by a welded seam (11) which extends along an edge (12) of the shells (3, 4) in the connecting area (10), running around the pipe (5) on the end with regard to the longitudinal direction (13) of the pipe.

To improve the durability of the sheet metal component (1), the shells (3, 4) are designed in the connecting area (10) so that they protrude beyond a longitudinal end (14) of the butt edges (8, 9) in the longitudinal direction (13) of the pipe (5) and are spaced a distance apart from one another.




Inventors:
Hildebrand, Joachim (Aichwald, DE)
Application Number:
12/257800
Publication Date:
04/30/2009
Filing Date:
10/24/2008
Primary Class:
International Classes:
B21C37/08; F01N13/08; F01N13/18
View Patent Images:



Foreign References:
WO2007134865A12007-11-29
EP10612402000-12-20
Primary Examiner:
DRIGGERS, GWENDOLYN YVONNE
Attorney, Agent or Firm:
FISHMAN STEWART PLLC (39533 WOODWARD AVENUE SUITE 140, BLOOMFIELD HILLS, MI, 48304-0610, US)
Claims:
1. A sheet metal component for an exhaust system comprising: a body comprising at least two shells wherein the at least two shells include butt edges; at least one pipe; a tubular connecting area created by the at least two shells, the connecting area adjacent to the pipe on the outside; and a welded seam extending along an edge of the at least two shells in the connecting area, the edge surrounding the pipe on an end of the pipe with regard to the longitudinal direction of the pipe; wherein the at least two shells are joined together along the butt edges and are in contact with one another; wherein the interconnected butt edges of the at least two shells extend into the connecting area; wherein the pipe is connected to the at least two shells by the welded seam; wherein the at least two shells protrude in the connecting area over a longitudinal end of the butt edges in the longitudinal direction of the pipe and are spaced a distance apart from one another.

2. The sheet metal component according to claim 1, characterized in that the edge of the at least two shells has a symmetrical course at least in a section which leads away from the longitudinal end of the butt edges.

3. The sheet metal component according to claim 1, characterized in that in the connecting area the distance between the at least two shells increases with an increase in the distance from the longitudinal end of the butt edges.

4. The sheet metal component according to claim 1, characterized in that the at least two shells are shaped in the connecting area so that a tangent to the curve of the end edge in the longitudinal end of the butt edges runs at a right angle to the longitudinal direction of the butt edges.

5. The sheet metal component according to claim 1, characterized in that the at least two shells are shaped in the connecting area so that the curve of the end edge has an arc-shaped segment in the area of the longitudinal end of the butt edges.

6. The sheet metal component according to claim 1, characterized in that the at least two shells protrude approximately one-third of the diameter of the pipe beyond the longitudinal end of the butt edges in the connecting area.

7. The sheet metal component according to claim 1, characterized in that another pipe which is connected by a peripheral welded seam to an axial end of the outer pipe is inserted into the pipe.

8. The sheet metal component according to claim 7, characterized in that the axial end of the outer pipe is shaped to be run in the same way as the curve of the end edge of the at least two shells.

9. The sheet metal component according to claim 7, characterized in that the welded seam for connecting the inner pipe to the outer pipe and the welded seam for connecting the outer pipe to the at least two shells are designed as a two-plate lap seam or as a three-plate lap seam.

10. The sheet metal component according to claim 1, characterized in that the sheet metal component is one of a shell bend, a catalytic converter, a particulate filter, a muffler, a pipe assembly and a pipe branch.

11. The sheet metal component according to claim 2, characterized in that the sheet metal component is one of a shell bend, a catalytic converter, a particulate filter, a muffler, a pipe assembly and a pipe branch.

12. The sheet metal component according to claim 2, characterized in that in the connecting area the distance between the at least two shells increases with an increase in the distance from the longitudinal end of the butt edges.

13. The sheet metal component according to claim 2, characterized in that the at least two shells are shaped in the connecting area so that a tangent to the curve of the end edge in the longitudinal end of the butt edges runs at a right angle to the longitudinal direction of the butt edges.

14. The sheet metal component according to claim 2, characterized in that the at least two shells are shaped in the connecting area so that the curve of the end edge has an arc-shaped segment in the area of the longitudinal end of the butt edges.

15. The sheet metal component according to claim 2, characterized in that the at least two shells protrude approximately one-third of a diameter of the pipe beyond the longitudinal end of the butt edges in the connecting area.

16. The sheet metal component according to claim 2, characterized in that another pipe which is connected by a peripheral welded seam to an axial end of the outer pipe is inserted into the pipe.

17. The sheet metal component according to claim 3, characterized in that the at least two shells are shaped in the connecting area so that a tangent to the curve of the end edge in the longitudinal end of the butt edges runs at a right angle to the longitudinal direction of the butt edges.

18. The sheet metal component according to claim 3, characterized in that the at least two shells are shaped in the connecting area so that the curve of the end edge has an arc-shaped segment in the area of the longitudinal end of the butt edges.

19. The sheet metal component according to claim 3, characterized in that the at least two shells protrude approximately one-third of the diameter of the pipe beyond the longitudinal end of the butt edges in the connecting area.

20. The sheet metal component according to claim 8, characterized in that the welded seam for connecting the inner pipe to the outer pipe and the welded seam for connecting the outer pipe to the at least two shells are designed as a two-plate lap seam or as a three-plate lap seam.

Description:

The present invention relates to a sheet metal part, in particular of an exhaust gas system.

In a number of applications, sheet metal parts having a body comprising at least two shells and at least one pipe are used. For example, housings manufactured in the half-shell type of construction with a pipe leading out of the housing are conceivable. The half-shells are then joined together along butt edges, e.g., by a welded seam. The half-shells may form a tubular connecting area that is in contact with the pipe on the outside for connection of the pipe in which the butt edges of the half-shells that are joined together extend. The pipe may then be joined to the half-shells by a welded seam, such that this welded seam extends along an edge of the shells surrounding the pipe in the connecting area, said edge being on the end with respect to the longitudinal direction of the pipe. This edge on the end usually runs around the pipe by the shortest path and is thus usually in a plane extending perpendicular to the longitudinal direction of the pipe. In the case of a circular cross section of the pipe, the edge on the end thus has a circular course, so that the welded seam is also circular between the pipe and the half-shells.

It has been found that high loads occur during operation of vehicles equipped with exhaust gas systems in particular and may result in failure of the welded joint between the pipe and the shell body.

The present invention relates to the problem of providing an improved embodiment for a sheet metal component of the type defined in the introduction such that this embodiment is characterized in particular by the fact that it has an increased lifetime.

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

The invention is based on the general idea of lengthening the shells which are in contact with the pipe in the connecting area beyond a longitudinal end of the adjacent butt edges in the longitudinal direction of the pipe in such a way that the areas of the shells protruding beyond the longitudinal end of the butt edges are spaced a distance apart from one another. In a view from the side, this yields a wedge-shaped or valley-shaped pattern for the end edge in which this end edge approaches the longitudinal end along its course from an area of one shell at a distance from the longitudinal end of the butt edges and is again at a distance from the longitudinal end on the other shell. Due to the proposed embodiment of the shells in the connecting area, this yields an extension of the welded seam in proximity to the longitudinal end of the butt edges, which increases the connecting forces between the pipe and the shells or at least distributes the forces more uniformly. At the same time, this reduces the stress peaks in the area of the longitudinal end of the butt edges, which lowers the total load on the welded seam in the area of the longitudinal end. Accordingly, the durability of the welded joint between the pipe and the shell body is thereby increased.

An embodiment in which the end edge on the two shells has a symmetrical course at least in a section starting from the longitudinal end of the butt edges is advantageous. Due to the symmetry of the welded seam, the most uniform possible stress distribution within the welded seam under loads can be implemented.

According to another advantageous embodiment, the distance between the two shells in the connecting area may increase with an increase in the distance from the longitudinal end of the butt edges. This implements the smoothest possible transition between the part of the welded seam leading past the longitudinal end of the butt edges and the parts of the welded seam which are in the sections of the shells remote from the longitudinal end. This also leads to a reduction in stress peaks within the welded seam.

In another advantageous embodiment, it is also possible to provide for the two shells to be shaped in the connecting area so that a tangent to the course of the end edge in the longitudinal end of the butt edges runs perpendicular to the longitudinal direction of the butt edges. This design also achieves a reduction in stress peaks, especially in the area of the longitudinal end.

Other important features and advantages of the invention are derived from the dependent claims, the drawings and the respective description of the figures on the basis of the drawings.

It is self-evident that the features mentioned above and those yet to be described below may be used not only in the particular combination given but also in other combinations or alone without going beyond the scope of the present invention.

Preferred exemplary embodiments of the invention are depicted in the drawings and explained in greater detail in the following description, where the same reference numerals refer to the same or similar or functionally identical components.

They each show schematically:

FIGS. 1 through 5 each show a greatly simplified side view of a sheet metal component in the area of a welded joint between a pipe and a shell body in various embodiments.

According to FIGS. 1 through 5, a sheet metal component 1, which may preferably be a component of an exhaust system, comprises a body 2, which consists of at least two shells 3 and 4 and may also be referred to below as a shell body 2. It is clear that the body 2 may also consist of more than two shells 3, 4. If there are only two shells 3, 4 present, they may be half-shells, but that is not absolutely necessary. The shells 3, 4 are molded sheet metal parts, i.e., made of metal. Furthermore, the sheet metal component 1 has at least one pipe 5, which is connected by a welded joint 6 to the shell body 2. It is clear that the sheet metal component 1 may essentially also have two or more such pipes 5, which may be connected to the shell body 2 via corresponding welded joints 6. The pipe 5 is also made of metal.

The two shells 3, 4 shown here each have a butt edge 8 and/or 9 along a dividing line 7. In the assembled state, the two butt edges 8, 9 are in contact with one another along the dividing line 7. Furthermore, the two shells 3, 4 are joined together along their butt edges 8, 9, which are in contact with one another. To this end, a welded seam which is not shown in greater detail here may also be provided. Essentially, the butt edges 8, 9 may also be joined together by flanging.

The two shells 3, 4 form a tubular connecting area 10, which is symbolized here by curly brackets. In this connecting area 10, the shells 3, 4 are in surface contact with the pipe 5 on the outside. The butt edges 8, 9 extend into one another in this connecting area 10.

The pipe 5 is connected to the shell body 2 via the welded joint 6. To this end, the welded joint 6 comprises a continuous welded seam 11, extending in the connecting area 10 along an edge 12 of the shells 3, 4, which surrounds the pipe 5 and is designed with regard to a longitudinal direction 13 of the pipe 5 at the end.

The dividing line 7 along which the two butt edges 8, 9 are in contact with one another defines a longitudinal direction of the butt edges 8, 9. The butt edges 8, 9 end in the connecting area 10 at a longitudinal end 14. According to the invention the two shells 3, 4 are designed in the connecting area 10 so that they each protrude beyond the longitudinal end 14 in the longitudinal direction 13 of the pipe 5 and are spaced a distance apart from one another. To this end, the edge 12 at the end has the wavy pattern, which is shown here in a side view where the valley of the curve comes in contact with the longitudinal end 14 of the butt edges 8, 9. Since the welded seam 11 extends along the end edge 12, the welded seam 11 follows this specific curve of the edge 12. Due to this design of the shells 3, 4, the welded seam 11 is longer than a welded seam which surrounds the pipe 5 along a plane running at a right angle to the longitudinal direction 13. The strength of the welded joint 6 can be increased by this measure alone. However, the shaping of the shells 3, 4, which is performed in a targeted manner in the area of the longitudinal end 14, leads at the same time to a significant relaxation of tension on the welded seam 6 in the area of the longitudinal end 14 because through this measure the forces to be transferred from the pipe 5 to the shells 3, 4 are distributed over a larger area. The durability of the welded joint 6 can be increased in this way.

The sections of the shells 3, 4 protruding beyond the longitudinal end 14 of the butt edges 8, 9 are also referred to below as protrusions 15 and/or 16.

In the examples shown here, the end edge 12 has a symmetrical course. In particular the edge 12 and thus also the welded seam 11 are designed with mirror symmetry with respect to a plane in which the dividing line 7 is situated at least in the connecting area 10.

In the embodiments illustrated here, it is noteworthy that in the connecting area 10, the distance between the protrusions 15, 16 increases with an increase in the distance from the longitudinal end 14. This yields the wedge shape of the clearance formed between the protrusions 15, 16 tapering in the direction of the longitudinal end 14. It is possible in this way to achieve a gradual transition in the course of the edge 12 and thus the welded seam 11 between the area assigned to the longitudinal end 14 and the areas at a distance from that.

In FIG. 1, a tangent 17 has also been drawn to the curve of the end edge 12 and extends through the longitudinal end 14. This tangent 17 extends perpendicular to the longitudinal direction, which has the butt edges 8, 9 at least in the connection area 10. In this way, the stresses within the welded seam 11 can be reduced in the area of the longitudinal end 14. For this purpose, the two shells 3, 4 may be shaped in the area of their protrusions 15, 16 so that the course of the edge 12 in the area of the longitudinal end 14 has an arc segment of a circle. The radius of this arc segment of the circle may have, for example, 10% of the diameter 18 of the pipe 5, at least in the connecting area 10. Merely as an example and without any restriction on general validity, this radius may be 5 mm, for example.

The edge 12 may be a distance of up to a distance 19 away from the longitudinal end 14 within the protrusions 15, 16, for example. This distance 19 may amount to one-third of the diameter 18, for example.

The embodiments according to FIGS. 1 and 2 differ only in the design of the shell body 2. FIG. 1 shows an embodiment in which the sheet metal component 1 may be, for example, a pipe assembly or a pipe branch, which may be designed in the manner of a Y-hose or an X-hose, for example. In contrast with that, FIG. 2 shows an embodiment in which the sheet metal part 1 may be a catalyst or a particulate filter or a muffler. In addition, any other embodiments are also conceivable for the sheet metal component 1, e.g., an exhaust bend in the shell design and the like, such that not only may sheet metal components 1 be considered as components of an exhaust system, but also fundamentally any other applications are also conceivable.

In the embodiments according to FIGS. 3 through 5, another pipe 20, which is connected to the other pipe 5 via another welded joint 21 is also inserted into the pipe 5. The exterior pipe 5 is also referred to below as the outer pipe 5, while the interior pipe 20 is also referred to below as the inner pipe 20. The additional welded joint 21 joining the two pipes 5, 20 together comprises a peripheral welded seam 22 which joins an axial end 23 of the outer pipe 5 to the outside of the inner pipe 20. The inner pipe 20 and the outer pipe 5 may also be exchanged.

In the embodiment shown in FIG. 3, the outer pipe 5 extends only slightly beyond the end edge 12 of the shell body 2. This yields the possibility of designing the two welded seams 11 and 22 as two-plate lap seam in at least some areas. This two-plate lap seam also has an overlap in the marked area 24 at the part of the welded seam 11 which leads to the longitudinal edge 14 and returns back from that.

In the embodiment shown in FIG. 4, the outer pipe 5 protrudes comparatively far beyond the end edge 12 of the shell body 2, so that the two welded seams 11, 22 may be designed to be completely separate from one another.

In the embodiment shown in FIG. 5, the axial end 23 of the outer pipe 5 expediently has the same course as the end edge of the shell body 2. This leads to the possibility of welding the inner pipe 20, the outer pipe 5 and the shell body 2 to one another with a common three-plate lap seam. The individual welded seams 11, 22 coincide with this; likewise the welded joints 6, 21. In the side view shown in FIG. 5, the axial end 23 of the outer pipe 5 is designed to coincide with the protrusions 15, 16 of the shell body 2.