Title of Invention

HOUSING FOR A COMPONENT OF AN EXHAUST SYSTEM AND METHOD OF PRODUCING SUCH A HOUSING

Abstract

The invention relates to a housing (10) for a component (16) of an exhaust system, in particular for an exhaust gas purification device, having an envelope (12) which comprises a shrunk clamping portion (20) for the component (16), and a transition portion (24) which adjoins the clamping portion (20) in the axial direction, and a connecting portion (26) which adjoins the transition portion (24) in the axial direction and the diameter of which is larger than that of the clamping portion (20). The invention also relates to a method of producing a housing (10) for a component (16) of an exhaust system by means of the following steps A tubular envelope (12) is provided. The component (16) is then inserted into the envelope (12) A shrinking step is then carried out in the clamping portion (20) which terminates spaced apart from the ends of the envelope (12) as viewed in the axial direction, whereas the axial ends of the envelope (12) are not acted upon.

Full Text

PCT/EP2006/008683 Housing for a Component of an Exhaust System and Method of Producing Such a Housing The invention relates to a housing for a component of an exhaust system, in particular for an exhaust gas purification device. The invention also relates to a method of producing a housing for a component of an exhaust system. The component can be in particular a diesel particulate filter or a catalyst. These are mounted within the housing along with a support mat. Most recently, a manufacturing method which is generally called "calibration" has often been used therefor. In this method, the housing is provided so as to have an envelope which is closed in the circumferential direction. The component is then pushed into the envelope along with the support mat, and the envelope is then upset in the radial direction until the component, along with the support mat, is retained within the housing with the desired pressure. This method is also known as "shrinking process". In modern shrinking methods, each envelope is shrunk individually, that means that the individual dimensions of the component and of the support mat are taken into account. This results in the diameter of the shrunk housing varying within determined limits. To permit the coupling of the housing, along with the component inserted therein, to an exhaust system, an inlet cone and an outlet cone are usually mounted upstream and downstream of the housing. Since these are always made available with the same diameter, it is provided in modern shrinking methods to calibrate the axial ends of the housing for the component after the shrinking step such that independently of the individual shrinking, the housing has always the same diameter at least at its axial ends. This method is generally costly. The object of the invention is to provide a housing for a component of an exhaust system which permits the coupling of an inlet cone or of an outlet cone with low effort. The object of the invention also consists in providing a method for a simplified manufacturing of such a housing. -2- For this purpose, provision is made according to the invention for a housing for a component of an exhaust system, in particular for an exhaust gas purification device, the housing having an envelope which comprises a shrunk clamping portion for the component, and a transition portion which adjoins the clamping portion in the axial direction, and a connecting portion which adjoins the transition portion in the axial direction and the diameter of which is larger than that of the clamping portion. The following steps are provided in the method according to the invention: A tubular envelope is at first provided The component, along with the support mat, is then inserted into the envelope. The envelope is then shrunk in a clamping portion which terminates spaced apart from the ends of the envelope, as viewed in the axial direction, whereas the axial ends of the envelope are not acted upon. The invention is based on the surprising finding that if the envelope is shrunk only in a central region and a short portion at the axial ends of the envelope remains unworked, the diameter and also the angle of these unworked portions depend only to a very low degree on the diameter of the shrunk central region. In other words: An approximately truncated connecting portion is always produced at the axial ends of the envelope independently of the diameter to which the central region is shrunk, the diameter and the angular orientation of this connecting portion varying only to a small extent such that it is suitable for the coupling of the inlet cone or of the outlet cone without further working steps. According to the preferred embodiment of the invention, the envelope terminates approximately flush with the component in the axial direction when the latter is received within the housing. This constitutes a particular advantage of the method according to the invention and of the housing according to the invention, since it is possible to configure the envelope shorter than in the prior art. In the prior art, the envelope must project beyond the component in the axial direction, since otherwise, the calibration of the axial ends of the envelope is impossible The invention however takes the finding into account that the diameter of the envelope increases at the axial ends when the clamping portion is shrunk, so that enough space is available for receiving the inlet cone or the outlet cone. This is surprising in so far as the change in the diameter at the axial end of the envelope is exactly opposite to that of the diameter of the clamping portion. -3- The invention is described below with reference to one embodiment which is illustrated in the enclosed drawings, in which: - Figure 1 shows a schematic section of the housing according to the invention; - Figure 2 shows the detail II of Figure 1 on an enlarged scale; and - Figure 3 shows schematically the shape of the envelope before and after the shrinking process. Figure 1 shows a housing 10 which consists of an envelope 12 and of two coupling parts 14, only one of them being shown in the present case. The coupling parts are an inlet cone or an outlet cone by means of which the housing may be coupled to an exhaust system of a combustion engine. A component 16 of the exhaust system, in particular a diesel particulate filter or a catalyst, is arranged within the housing 12. The component 16 is surrounded by a support mat 18. In the initial state, i.e. before the mounting of the component 16, the envelope 12 has a diameter DA (cf. Figure 3). The envelope need not necessarily have a circular cross-section but may have an oval, a tri-oval or other cross-section. In the initial state, a length L of the envelope 12 projects beyond a clamping portion 20 in which a shrinking tool 22 engages the envelope and upsets the latter in the radial direction, as can also be seen in Figure 3. As a result of the upsetting of the envelope in the region of the clamping portion, the diameter at this location is reduced to the end diameter DE (cf. Figure 3 again) so that the component 16 is firmly retained within the envelope along with the support mat 18 During the upsetting or shrinking step, the region of the envelope, which projects beyond the shrinking tool 22 in the axial direction is deformed in the way shown in Figure 3. A transition portion 24 which has an arcuate cross-section and in which the diameter of the envelope is outwardly enlarged adjoins the radially inwardly upset clamping portion 20, and a connecting portion 26 which is approximately truncated and has its maximum diameter at the axial end of the envelope 12 adjoins the transition portion 24. The connecting portion 26 has an angle of inclination a, and the diameter of the envelope at the outer end of the connecting portion 26 is larger than the initial diameter DA. It must also be noted that the -4- total length of the envelope increases during the shrinking process since half of the reduction of the diameter of the envelope results in an increased wall thickness and the other half in an increased length. In modern shrinking methods, the end diameter DE is adapted to the respective diameter of the component 16. It is however remarkable that changes in the end diameter DE leads only to a negligible degree to changes in the diameter of the connecting portion 26 and in the angle a. It was found in tests that in case of a shrinking for example from an initial diameter of 158.4 mm to a set diameter of 152.8 mm and of an individual adaptation of the end diameter DE by ± 1mm in relation to the set diameter, an insignificant change in the diameter of the connecting portion in the range of ± 0.1 mm could be observed. The length L by which the envelope projects beyond the shrinking tool 22 in the initial state varied here between 15 and 24 mm. Since the diameter and the angle of the connecting portion 26 always remain almost constant despite changes in the end diameter DE, it is possible to apply a standard coupling part 14 to each individually shrunk envelope 12. As can be seen in Figures 1 and 2, this standard coupling part may have, for example, a conically extending coupling portion 15 which is inserted into the connecting portion 26. The envelope 12 and the coupling part 14 can then be connected, for example welded or soldered to each other. A further advantage which occurs if only part of the length of the envelope 12 is shrunk consists in that the connecting portion 26 is widened in comparison with the initial diameter so that the coupling part 14 can be inserted into the space between the component 16 and the envelope 12. As can be clearly seen in Figures 1 and 2, the coupling part 14 overlaps the component 16. This results in a housing which is particularly compact in the axial direction. The fact that the component 16 is freely received within the housing at its axial ends rather than clamped over its entire length does not impair the clamping between the envelope 12 and the component 16. -5- List of Reference Numbers: 10: housing 12: envelope 14: coupling part 15: coupling portion 16: component 18: support mat 20: clamping portion 22: shrinking tool 24: transition portion 26: connecting portion DA: initial diameter DE: end diameter a: angle of inclination L: projecting length -6- Claims 1. A housing (10) for a component (16) of an exhaust system, in particular for an exhaust gas purification device, having an envelope (12) which comprises a shrunk clamping portion (20) for the component (16), and a transition portion (24) which adjoins the clamping portion (20) in the axial direction, and a connecting portion (26) which adjoins the transition portion (24) in the axial direction and the diameter of which is larger than that of the clamping portion (20). 2. The housing according to claim 1, characterized in that the connecting portion (26) has the shape of a portion of a cone. 3. The housing according to claim 1, characterized in that the connecting portion (26) is part of a hyperboloid. 4. The housing according to any of the preceding claims, characterized in that the component (16) is received within the housing (10) and in that the envelope (12) terminates approximately flush with the component (16) in the axial direction. 5. The housing according to any of the preceding claims, characterized in that it comprises a coupling part (14) which is connected to the envelope (12) and has an obliquely extending coupling portion (15) which is inserted into or slipped on the connecting portion (26) and is firmly connected to the envelope (12). 6. The housing according to claim 5, characterized in that the coupling part (14) is welded, soldered or bonded to the housing (10). 7. The housing according to any of the preceding claims, characterized in that the component (16) is a ceramic substrate which is surrounded by a support mat (18). 8. A method of producing a housing (10) for a component (16) of an exhaust system by means of the following steps: a tubular envelope (12) is provided; the component (16) is inserted into the envelope (12); -7- the envelope (12) is shrunk in a clamping portion (20) which terminates spaced apart from the ends of the envelope (12) as viewed in the axial direction, whereas the axial ends of the envelope (12) are not acted upon. 9. The method according to claim 8, characterized in that a coupling part (14) is slipped on or inserted into the envelope (12) without further working steps for influencing the diameter of the axial ends being carried out. The invention relates to a housing (10) for a component (16) of an exhaust system, in particular for an exhaust gas purification device, having an envelope (12) which comprises a shrunk clamping portion (20) for the component (16), and a transition portion (24) which adjoins the clamping portion (20) in the axial direction, and a connecting portion (26) which adjoins the transition portion (24) in the axial direction and the diameter of which is larger than that of the clamping portion (20). The invention also relates to a method of producing a housing (10) for a component (16) of an exhaust system by means of the following steps A tubular envelope (12) is provided. The component (16) is then inserted into the envelope (12) A shrinking step is then carried out in the clamping portion (20) which terminates spaced apart from the ends of the envelope (12) as viewed in the axial direction, whereas the axial ends of the envelope (12) are not acted upon.

Documents:

01212-kolnp-2008-abstract.pdf

01212-kolnp-2008-claims.pdf

01212-kolnp-2008-correspondence others.pdf

01212-kolnp-2008-description complete.pdf

01212-kolnp-2008-drawings.pdf

01212-kolnp-2008-form 1.pdf

01212-kolnp-2008-form 2.pdf

01212-kolnp-2008-form 3.pdf

01212-kolnp-2008-form 5.pdf

01212-kolnp-2008-international publication.pdf

01212-kolnp-2008-international search report.pdf

01212-kolnp-2008-pct priority document notification.pdf

01212-kolnp-2008-pct request form.pdf

1212-KOLNP-2008-(06-11-2012)-CORRESPONDENCE.pdf

1212-KOLNP-2008-(21-03-2014)-ANNEXURE TO FORM 3.pdf

1212-KOLNP-2008-(21-03-2014)-CORRESPONDENCE.pdf

1212-KOLNP-2008-(21-03-2014)-OTHERS.pdf

1212-KOLNP-2008-(21-03-2014)-PETITION UNDER RULE 137.pdf

1212-KOLNP-2008-CORRESPONDENCE 1.2.pdf

1212-KOLNP-2008-CORRESPONDENCE OTHERS 1.1.pdf

1212-kolnp-2008-form 18.pdf

1212-KOLNP-2008-INTERNATIONAL EXM REPORT.pdf

1212-KOLNP-2008-INTERNATIONAL SEARCH REPORT 1.1.pdf

1212-KOLNP-2008-OTHERS.pdf

1212-KOLNP-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

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