Method for producing an exhaust-gas aftertreatment device

Patent metadata

Field	Value
Publication number	US-9765681-B2
Application number	US-201314397580-A
Country	US
Kind code	B2
Filing date	May 13, 2013
Priority date	May 21, 2012
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A method for producing an exhaust-gas aftertreatment device inserts a monolith in a housing, assembled from a circumferentially enclosed jacket and two end funnels. The monolith is axially inserted into the jacket with a circumferentially enclosing support mat. The funnels are connected to the jacket via an axial connecting section shaped complementary to the cross-section of the jacket, such that each connecting section and an axial end section of the support mat axially overlap. The jacket, including the connecting sections of the funnels are reduced from a starting cross-section to an end cross-section. This produces a predetermined radial preload in the support mat in a support area extending from the one connecting section to the other connecting section to retain the monolith in the jacket.

First claim

The invention claimed is:

1. A method for producing an exhaust gas aftertreatment device comprising a housing assembled of a jacket, closed in circumferential direction, and two face end funnels and at least one monolith for the exhaust gas aftertreatment, the method comprising the steps of:
assembling and filling the housing, for the purpose of which the at least one monolith together with at least one bearing mat, enclosing the at least one monolith in the circumferential direction, is axially inserted in the jacket, and for the purpose of which the funnels are each plugged into the jacket or plugged onto the jacket with an axial connecting section which is formed complementarily to a cross section of the jacket in such a manner that the respective connecting section and an axial end section of the bearing mat axially overlap in an overlap region; and
calibrating the housing, for the purpose of which the jacket including the connecting sections of the funnel, starting out from an initial cross section, is reduced to a final cross section in order to create in the at least one bearing mat, at least in a bearing region extending from the one connecting section to the other connecting section, a predetermined radial preload for retaining the at least one monolith in the jacket, wherein the housing is calibrated after the funnels are each plugged into the jacket or plugged onto the jacket.

2. The method according to claim 1 , wherein calibrating is carried out so that an outer cross section of the jacket is constant over the entire axial length of the bearing region and comprises a stepped-section in end regions which are plugged in contact with the connecting sections.

3. The method according to claim 2 , wherein the cross-sectional reduction in the bearing region is greater by a wall thickness of a respective connecting section than in the connecting section.

4. The method according to claim 2 , wherein calibrating is carried out with a calibrating tool, which comprises a pushing contour formed complementarily to an outer contour of the jacket for applying pressure forces reducing the cross section of the jacket, wherein the calibrating tool comprises a step, in a region of one of the connecting sections.

5. The method according to claim 1 , wherein calibrating is carried out so that an outer cross section of the jacket, including end regions plugged with the connecting sections, is constant over an entire axial length of the jacket.

6. The method according to claim 5 , wherein the at least one bearing mat in the respective overlap region has at least one of a reduced wall thickness and a reduced density.

7. The method according to claim 1 , wherein the funnels are fastened to the jacket after assembling and before calibrating.

8. The method according to claim 1 , wherein the funnels, after calibrating, are each fastened to the jacket through at least one closed circumferential weld seam.

9. The method according to claim 1 , wherein:
before assembling the housing at least one of the at least one monolith and the at least one bearing mat is measured in order to determine parameters required for calibrating and
calibrating is carried out dependent on previously determined parameters.

10. The method according to claim 1 , wherein the funnels are formed separate from the housing, the at least one bearing mat comprising a planar bearing mat surface extending continuously, without interruption, from an end of one of the funnels to an end of another one of the funnels, the jacket comprising an inner planar jacket surface, the inner planar jacket surface being in direct contact with the planar bearing mat surface in the bearing region of the at least one bearing mat.

11. The method according to claim 1 , wherein the jacket comprises a planar jacket end portion, the axial connecting section comprising a planar axial connecting end portion, the planar jacket end portion being in direct contact with the planar axial connecting end portion during calibration of the housing.

12. A method for producing an exhaust gas aftertreatment device, the method comprising:
enclosing at least one monolith in a circumferential direction of the at least one monolith with at least one bearing mat to form a monolith bearing mat structure;
inserting the monolith bearing mat structure in a jacket of a housing in an axial direction of the jacket;
connecting funnels to the jacket, wherein one of the funnels is connected one end of the jacket and another one of the funnels is connected to another end of the jacket, each of the funnels comprising an axial funnel connecting section, the axial funnel connecting section being formed complementarily to a cross section of the jacket, the axial funnel connecting section axially overlapping an axial end section of the at least one bearing mat and an axial end section of the jacket axially with respect to the axial direction of the jacket to define an axial overlap region, the at least one bearing mat comprising a bearing region extending from the axial funnel connecting section of the one of the funnels to the axial funnel connecting section of the another one of the funnels;
applying a force to the housing after each end of the jacket is connected to a respective funnel such that a predetermined radial preload is created in at least the bearing region to retain the at least one monolith in the jacket, the housing comprising an initial cross section dimension prior to the force being applied to the housing, the housing comprising a final cross section dimension after the force is applied to the housing, the final cross section dimension being less than the initial cross section dimension.

13. The method according to claim 12 , wherein the force is applied so that an outer cross section of the jacket is constant over an entire axial length of the bearing region and the jacket comprises a stepped-section in end regions which are in contact with the connecting sections.

14. The method according to claim 13 , wherein a cross-sectional reduction in the bearing region is greater by a wall thickness of a respective connecting section than in the connecting section.

15. The method according to claim 13 , wherein the force is applied via a calibrating tool, the calibrating tool comprising a pushing contour formed complementarily to an outer contour of the jacket for applying pressure forces reducing a cross section of the jacket, wherein the calibrating tool comprises a step in a region of the axial funnel connecting section of one of the funnels.

16. The method according to claim 12 , wherein the force is applied to the housing so that an outer cross section of the jacket, including end regions connected with the axial funnel connecting sections, is constant over an entire axial length of the jacket.

17. The method according to claim 16 , wherein the at least one bearing mat in the respective overlap region has at least one of a reduced wall thickness and a reduced density.

18. The method according to claim 12 , wherein each of the funnels is formed separate from the housing, the at least one bearing mat comprising a planar bearing mat surface extending continuously, without interruption, from an area adjacent to an end of one of the funnels to a region adjacent to an end of another one of the funnels, the jacket comprising an inner planar jacket surface, the inner planar jacket surface being in direct contact with the planar bearing mat surface in the bearing region of the at least one bearing mat.

19. The method according to claim 12 , wherein

Assignees

• Eberspächer Exhaust Tech Gmbh & Co Kg

Inventors

• Wirth Georg
• Müller Bernd

Classifications

• B23P15/00

  Making specific metal objects by operations not covered by a single other subclass or a group in this subclass · CPC title

• B23P2700/03

  Catalysts or parts thereof · CPC title

• F01N2450/20

  by mechanical joints, e.g. by deforming housing, tube, baffle plate or parts thereof · CPC title

• F01N2450/02

  Fitting monolithic blocks into the housing · CPC title

• F01N2450/22

  by welding or brazing · CPC title