Exhaust Gas Aftertreatment Device

Abstract

A device for treating exhaust gases of an internal combustion engine includes: a heating disk arranged in a housing; and a main catalytic converter arranged downstream of the heating disk in the flow direction in the housing. The flow can pass through the heating disk and the main catalytic converter in the flow direction along a plurality of flow channels. The heating disk is formed from a metallic honeycomb body and the main catalytic converter is formed from a ceramic honeycomb body fixed in relation to the housing by a fixing structure. The heating disk is electrically contacted by an electrical feedthrough guided through the housing from the outside to the inside.

Claims

1.-12. (canceled)

13. A device for treating exhaust gases of an internal combustion engine, comprising: a heating disk (2) arranged in a housing (1); and a main catalytic converter (3, 13) arranged downstream of the heating disk (2) in the flow direction in the housing (1), wherein the flow can pass through the heating disk (2) and the main catalytic converter (3, 13) in the flow direction along a plurality of flow channels, wherein the heating disk (2) is formed from a metallic honeycomb body and the main catalytic converter (3, 13) is formed from a ceramic honeycomb body fixed in relation to the housing (1) by a fixing structure (6), wherein the heating disk (2) is electrically contacted by an electrical feedthrough (4) guided through the housing (1) from the outside to the inside.

14. The device as claimed in claim 13, wherein the outside diameter of the heating disk (2) is smaller than the inside diameter of the housing (1), with an annular air gap being formed between the housing (1) and the heating disk (2).

15. The device as claimed in claim 14, wherein the heating disk (2) is supported by a plurality of support pins (5, 15, 16) in relation to the main catalytic converter (3) and is spaced apart from the latter.

16. The device as claimed in claim 13, wherein the heating disk (2) is inserted into a ceramic half-shell (11).

17. The device as claimed in claim 16, wherein the ceramic half-shell (11) is fixed in relation to the housing (1) by a second fixing structure (9).

18. The device as claimed in claim 17, wherein the heating disk (2) formed by a metallic honeycomb body is pressed into the ceramic half-shell (11).

19. The device as claimed in claim 13, wherein one of the end faces of the honeycomb body of the main catalytic converter (13) has a recess (12) adapted to the shape of the heating disk (2), the heating disk (2) being pressed into the recess (12) in the honeycomb body (13).

20. The device as claimed in claim 19, wherein the honeycomb body of the main catalytic converter (13) has at least one bore running in the radial direction in the region of the recess, the electrical contacting of the heated disk (2) being guided through this bore to the heating disk (2).

21. The device as claimed in claim 13, wherein support pins (14) are guided through individual flow channels formed in the honeycomb body of the main catalytic converter (3) from the gas inlet side to the gas outlet side of the honeycomb body.

22. The device as claimed in claim 17, wherein the support pins (14) are fixed in relation to the gas inlet side and/or the gas outlet side.

23. The device as claimed in claim 22, wherein the support pins (14) protrude beyond the gas inlet side of the honeycomb body of the main catalytic converter (3) and the heating disk (2) is pressed onto the protruding regions of the support pins (14).

24. The device as claimed in claim 13, wherein the heating disk (2) is supported by support pins (16) in relation to a metallic honeycomb body serving as a support catalytic converter (17), the support catalytic converter (17) being connected on its outer circumference to the inner surface of the housing (1).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will be explained in detail in the following text on the basis of exemplary embodiments with reference to the drawings. In the drawings:

[0032] FIG. 1 shows a sectional view through a housing with a ceramic main catalytic converter, a metallic heating disk and with support pins which space the heating disk in relation to the main catalytic converter'

[0033] FIG. 2 shows a sectional view through a housing, with the heating disk being inserted into a ceramic half-shell spaced apart from the main catalytic converter;

[0034] FIG. 3 shows a sectional view through a housing, with the heating disk being inserted into a recess on the end face of the main catalytic converter;

[0035] FIG. 4 shows a sectional view through a housing, with the heating disk being supported in relation to the main catalytic converter by support pins which are guided through the entire main catalytic converter; and

[0036] FIG. 5 shows a sectional view through a housing, with the heating disk being supported by support pins in relation to a support catalytic converter mounted upstream of the main catalytic converter.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0037] FIG. 1 shows a sectional view, in which a casing tube 1 serves as a housing, a heating disk 2, a main catalytic converter 3, an electrical feedthrough 4, and support pins 5 which space the heating disk 2 from the main catalytic converter 3 are shown.

[0038] The heating disk 2 is formed by a metallic honeycomb body. The main catalytic converter 3 is a ceramic honeycomb body, which can be coated with a suitable coating, for example, in accordance with its purpose. The main catalytic converter is fixed in relation to the casing tube 1 by a swellable mat 6. In addition to its fixing effect, the swellable mat 6 can also have an electrical insulating effect.

[0039] The electrical feedthrough 4, two electrical feedthroughs 4 are provided in the example in FIG. 1, is used for electrical contacting of the heating disk 2. For this purpose, the electrical feedthrough 4 forms a temperature-resistant electrical conductor guide that is electrically insulating in relation to the casing tube 1. The electrical feedthrough 4, which is formed by a sleeve for example, can preferably be welded to the casing tube 1.

[0040] The support pins 5 can be produced from a metallic material or from a ceramic material. The support pins 5 are preferably inserted into individual flow channels of the honeycomb bodies of the heating disk 2 and of the main catalytic converter 3. To further secure the connection, the support pins 5 can be soldered to the honeycomb bodies, for example. The core task of the support pins 5 is to fix the heating disk 2 within the casing tube 1 such that the electrically contacted heating disk 2 does not come into electrically conductive contact with the casing tube 1.

[0041] FIG. 2 also shows an exhaust gas aftertreatment device. Identical parts are provided with the same reference signs from FIG. 1.

[0042] The main catalytic converter 3 is also supported in relation to the interior of the casing tube 7 using a swellable mat 6. The casing tube 7 has shoulders 8 on its inner surface, which are used for the axial fixing of the honeycomb bodies 3, 2 and the swellable mats 6, 9 used.

[0043] The shoulders can be arranged all the way around in the circumferential direction or only in sections.

[0044] The heating disk 2 is inserted into a ceramic half-shell 11. The heating disk 2 is fixed by mandrels 10 which can engage in individual flow channels of the heating disk 2 or can lie on the outer circumference of the heating disk 2. The heating disk 2 can form an interference fit with the ceramic half-shell 11, as a result of which it is fixed in the half-shell.

[0045] The ceramic half-shell 11 is fixed between the shoulders 8 by a second swellable mat 9. An air gap is formed between the heating disk 2 and the ceramic honeycomb body 3, as a result of which the two elements are spaced apart from one another in the axial direction.

[0046] The electrical feedthrough 4 is guided in the radial direction through the casing tube 7, the swellable mat 9 and optionally through the ceramic half-shell 11 in order to contact the heating disk 2.

[0047] FIG. 3 shows an arrangement, wherein the heating disk 2 is inserted into a recess 12 in the ceramic honeycomb body 13. The honeycomb body 13 is supported in relation to the casing tube 1 by a swellable mat 6. The electrical feedthrough 4 is guided through the casing tube 1, the swellable mat 6, and the honeycomb body 13 to the heating disk 2.

[0048] The recess 12 is introduced into the honeycomb body 13 on the end side and can form an interference fit with the heating disk 2 or can have some other fixing structure for the heating disk 2 in the honeycomb body 13. As also in FIG. 2, mandrels which engage in the flow channels of the heating disk 2 can also be provided.

[0049] FIG. 4 shows a structure with a ceramic honeycomb body 3, which is supported by a swellable mat 6 in relation to the casing tube 1. The heating disk 2 is electrically contacted by the electrical feedthrough or the feedthroughs 4.

[0050] In contrast to the preceding FIGS. 1 to 3, support pins 14 which are guided through the ceramic honeycomb body 3 are now shown here. The support pins 14 are guided along individual flow channels from the gas inlet side to the gas outlet side. The support pins 14 are fixed, for example screwed or clamped, in relation to the ceramic honeycomb body 3 with detents 15.

[0051] The heating disk 2 is then pressed onto the protruding end regions of the support pins 14 as a result of which the heating disk 2 is fixed at a distance from the ceramic honeycomb body 2 and from the inner wall of the casing tube 1.

[0052] FIG. 5 shows an embodiment with the ceramic honeycomb body 3, the swellable mat 6, the casing tube 1, the heating disk 2, and the electrical feedthroughs 4, as have already been shown in the previous Figures.

[0053] In contrast to the other embodiments, here the heating disk 2 is connected to a further metallic honeycomb body 17 by support pins 16. The further metallic honeycomb body 17 forms a so-called support catalytic converter. The support catalytic converter is used to fix the heating disk 2 inside the casing tube 1.

[0054] The support catalytic converter 17 has a larger diameter than the heating disk 2 and is in particular of such a size that it can be supported against the inner wall of the casing tube 1.

[0055] The heating disk 2 is spaced apart in the axial direction from the support catalytic converter 17 and the latter in turn is spaced apart from the ceramic honeycomb body 3. The support catalytic converter can, for example, be soldered to the casing tube in order to ensure secure fixing.

[0056] The different features of the individual exemplary embodiments may also be combined with one another.

[0057] The exemplary embodiments of FIGS. 1 to 5, in particular, have no limiting character and serve to illustrate the concept of the invention.

[0058] Although exemplary embodiments are explained in the above description, it should be noted that numerous modifications are possible. It should moreover be pointed out that the exemplary embodiments are merely examples which are not intended to limit the scope of protection, the applications and the structure in any way. Instead, the above description gives a person skilled in the art a guideline for the implementation of at least one exemplary embodiment, wherein various changes may be made, especially with regard to the function and arrangement of the integral parts described, without departing from the scope of protection as it is apparent from the claims and combinations of features equivalent thereto.