Support Pin For Catalytic Converter With Electrical Heating Disk

Abstract

A catalytic converter for aftertreatment of combustion gases from an internal combustion engine, having at least one catalyst and at least one electrically heatable heating disk. The catalyst and the heating disk are each formed by a honeycomb having a multitude of flow channels through which flow is possible in a main flow direction. The mechanical connection between the catalyst and the heating disk is formed by at least one support pin (having an inner core. The support pin has a thickening in each of the two end regions and, the core is formed by a ceramic material and the thickening is formed by a ceramic-metal mixture.

Claims

1.-10. (canceled)

11. A catalytic converter for aftertreatment of combustion gases from an internal combustion engine, comprising: at least one catalyst; at least one heating disk that is electrically heatable, wherein the at least one catalyst and the at least one heating disk are each formed by a honeycomb having a plurality of flow channels through which flow is possible in a main flow direction, and at least one support pin (1, 7, 10) configured to form a mechanical connection between the at least one catalyst and the at least one heating disk, comprising: an inner core formed by a ceramic material; and a thickening in each of its two end regions formed by a ceramic-metal mixture.

12. The catalytic converter as claimed in claim 11, wherein one or both thickenings at each end of the support pin have a cylindrical shape.

13. The catalytic converter as claimed claim 11, wherein one or both thickenings at each end of the support pin are formed by multiple superposed layers of a ceramic-metal mixture.

14. The catalytic converter as claimed in claim 11, wherein the thickenings at each end of the support pin, in axial direction of the support pin, have a distance from one another of at least 1 mm and not more than 10 mm.

15. The catalytic converter as claimed in claim 11, wherein a metal content in the ceramic-metal mixture increases with rising diameter, such that the metal content close to the inner core is lower than at an outer circumference of the thickening of the support pin.

16. The catalytic converter as claimed in claim 11, wherein the ceramic-metal mixture is nickel-based.

17. The catalytic converter as claimed in claim 13, wherein the layers that form the thickening form an adhesion promoter for bonding of the support pin to the respective honeycombs.

18. The catalytic converter as claimed in claim 17, wherein the adhesion promoter is one or more of copper, nickel, or alloys thereof.

19. The catalytic converter as claimed in claim 17, wherein the adhesion promoter has a coefficient of thermal expansion that is between a coefficient of thermal expansion of the honeycombs and a coefficient of thermal expansion of the ceramic material that forms the inner core.

20. The catalytic converter as claimed in claim 17, wherein the inner core projects at least on one side beyond the thickening at the end in a direction of axial extension of the support pin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The invention is described in detail hereinafter by working examples with reference to the drawings. The drawings show:

[0021] FIG. 1 is a sectional view through a support pin, especially the end region of the support pin;

[0022] FIG. 2 is a sectional view through a support pin with a ceramic core projecting beyond the thickening at the end; and

[0023] FIG. 3 is a sectional view through a support pin, with both end regions accommodated in a metallic honeycomb.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0024] FIG. 1 shows a section through a support pin 1. This has a ceramic core 2. At its two ends, although only one is shown, the support pin 1 has a thickening 3 formed by a coating 4 of a ceramic-metal mixture.

[0025] The support pin 1 is accommodated in a honeycomb 5. Only a portion of one corrugated layer of the honeycomb 5 is shown in FIG. 1. The support pin 1 is inserted here into one of the corrugations at the end. The corrugated layer indicated and the smooth layers that are not shown collectively form the flow channels of the honeycomb 5.

[0026] Between the support pin 1 and the honeycomb 5 is disposed an adhesion promoter 6 that serves for bonding between the honeycomb 5 and the thickening 3 of the support pin 1. An adhesion promoter 6 may, for example, be a solder, which is utilized for soldering of the honeycomb 5 to the ceramic-metal mixture 4 of the support pin 1.

[0027] The ceramic-metal mixture 4 may have different concentrations of ceramic or metal in the radial direction. For this purpose, the thickening 3 formed by the ceramic-metal mixture 4 may be formed, for example, from multiple layers each having different mixing ratios between the ceramic constituents and the metallic constituents.

[0028] FIG. 2 shows a further section view through a support pin 7, wherein, by contrast with FIG. 1, the support pin 7 has a ceramic core 8 that projects in axial direction beyond the end region of the support pin 7 defined by the thickening 8. The projecting section 9 of the ceramic core does not have any further ceramic-metal mixture coating. This is especially advantageous when the insulation distance created by the support pin is to be longer. By virtue of the purely ceramic section 9, the length identified by the letter s is obtained as an additional insulation zone. The section 9 preferably projects beyond the point of connection between the support pin and the honeycomb into the honeycomb.

[0029] Such a construction is especially advantageous when the support pin is utilized for electrical insulation of two metals in one of the end regions that bear different electrical charges, in order to prevent a short circuit between these.

[0030] FIG. 3 shows a further section through a support pin 10, wherein each end of support pin 10 in FIG. 3 is inserted into and bonded to a honeycomb indicated by a corrugated layer 11, 12. The support pin 10 likewise has thickenings at the end by a ceramic-metal mixture bonded to the honeycomb by an adhesion promoter and a suitable processing operation.

[0031] In FIG. 3, it can be seen how the two honeycombs connected to one another by the support pin 10 are spaced apart from one another by the distance 13. The distance 13 is defined essentially by the length of the support pin 10 and the length of the thickenings at the ends. The distance 13 is preferably large enough to prevent an electrical short circuit between the two honeycombs, and at the same time small enough for best possible assurance of the desired effects, for example the heating of a honeycomb by an electrically heated honeycomb.

[0032] The working examples of FIGS. 1 to 3, in particular, have no limiting character and serve to illustrate the concept of the invention.

[0033] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.