HONEYCOMB BODY WITH AN ELECTRIC HEATING DEVICE

Abstract

The invention relates to a honeycomb body with an electric heating device. The electric heating device includes at least one electrically insulating heating wire which is fixed by a pin assembly to a front side of a honeycomb body. The electrically insulated heating wire is positioned at a distance of at least five times and a maximum of fifteen times that of the wire diameter.

Claims

1. A honeycomb body arrangement, comprising: an electric heating device; at least one electrically insulated heating wire having a wire diameter, the at least one electrically insulated heating wire being part of the electric heating device; a pin arrangement; and a honeycomb body having a front side; wherein the at least one electrically insulated heating wire is connected to the front side of the honeycomb body by the pin arrangement.

2. The honeycomb body arrangement of claim 1, the electric heating device further comprising: a single heating wire; and a heating disk formed by the configuration of the single heating wire; wherein the heating disk is fixed at a uniform distance from the front side of the honeycomb body.

3. The honeycomb body arrangement of claim 1, further comprising: a plurality of pins, the plurality of pins being part of the pin arrangement; and a plurality of cavities formed as part of the honeycomb body; wherein each of the plurality of pins extends and is secured into a corresponding one of the plurality of cavities in the front side of the honeycomb body.

4. The honeycomb body arrangement of claim 1, wherein the pin arrangement is metallic.

5. The honeycomb body arrangement of claim 1, the at least one electrically insulated heating wire further comprising an oval wire cross section.

6. The honeycomb body arrangement of claim 1, the pin arrangement further comprising a plurality of pin passages, wherein the at least one electrically insulated heating wire extends through at least one of the plurality of pin passages.

7. The honeycomb body arrangement of claim 1, the electric heating device further comprising two electrodes, each electrode connected to an end of the at least one electrically insulated heating wire.

8. The honeycomb body arrangement of claim 1, further comprising a housing, wherein the electric heating device and the honeycomb body are arranged in the housing.

9. The honeycomb body arrangement of claim 1, further comprising: a plurality of heating devices; and a plurality of controllable power supply units; wherein one of the controllable power supply units supplies power to a corresponding one of the plurality of heating devices.

10. The honeycomb body arrangement of claim 1, wherein the distance between the at least one electrically insulated heating wire and the honeycomb body is at least five times greater than the wire diameter.

11. The honeycomb body arrangement of claim 1, wherein the distance between the at least one electrically insulated heating wire and the honeycomb body is a maximum of fifteen times greater than the wire diameter.

12. A motor vehicle having an exhaust gas aftertreatment system, comprising: a power supply unit; a honeycomb body arrangement; an electric heating device being part of the honeycomb body arrangement; and a control unit; wherein the control unit is connected to the power supply unit and to the honeycomb body arrangement.

13. The motor vehicle having an exhaust gas aftertreatment system of claim 12, further comprising: at least one electrically insulated heating wire having a wire diameter, the at least one electrically insulated heating wire being part of the electric heating device; a heating disk formed by the configuration of the at least one electrically insulated heating wire; and a honeycomb body having a front side; wherein the heating disk is fixed at a uniform distance from the front side of the honeycomb body.

14. The motor vehicle having an exhaust gas aftertreatment system of claim 13, further comprising: a pin arrangement; and a plurality of pins, the plurality of pins being part of the pin arrangement; a plurality of cavities formed as part of the honeycomb body; wherein each of the plurality of pins extends and is secured into a corresponding one of the plurality of cavities in the front side of the honeycomb body.

15. The honeycomb motor vehicle having an exhaust gas aftertreatment system of claim 14, the pin arrangement further comprising a plurality of pin passages, wherein the at least one electrically insulated heating wire extends through at least one of the plurality of pin passages.

16. The honeycomb motor vehicle having an exhaust gas aftertreatment system of claim 13, wherein the distance between the at least one electrically insulated heating wire and the honeycomb body arrangement is at least five times greater than the wire diameter.

17. The honeycomb motor vehicle having an exhaust gas aftertreatment system of claim 13, wherein the distance between the at least one electrically insulated heating wire and the honeycomb body arrangement is a maximum of fifteen times greater than the wire diameter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0029] FIG. 1 is a perspective view of a honeycomb body arrangement, according to embodiments of the present invention;

[0030] FIG. 2 is a perspective view of an alternate embodiment of a heating wire used as part of a honeycomb body assembly, according to embodiments of the present invention;

[0031] FIG. 3 is a diagram of a pin arrangement used as part of a honeycomb body assembly, according to embodiments of the present invention; and

[0032] FIG. 4 is a diagram of a motor vehicle having an exhaust gas aftertreatment system which incorporates a honey comb body arrangement, according to embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0034] In the figures, identical components are generally provided with the same reference signs. However, it should be noted that the respectively depicted design forms of the components or the interaction thereof in one figure do not have to be interpreted as necessarily belonging together. On the contrary, it is possible to combine components and/or functions from one figure with components and/or functions of at least one other figure.

[0035] It is likewise also possible to extract partial aspects or individual components from the figures and to consider them in isolation. It is only if explicitly stated otherwise hereinbelow that this does not apply.

[0036] FIG. 1 shows a honeycomb body arrangement 1 having an externally indicated housing 16, which usually also forms the external boundary of the line 26 through which the exhaust gas may flow. A honeycomb body 7 with its front side 6 is shown on the right (or downstream). The exhaust gas usually enters the honeycomb body 7 via the front side 6. The honeycomb body 7 is supplied with at least one at least partially structured metallic layer, with a metallic nonwoven, with a woven structure, with a grid and/or from an extruded material. By means of a pin arrangement 5, the electric heating device 2 is positioned at a predetermined distance 8 and supported against the front side 6. The heating device 2 shown here is designed in the manner of a heating disk 10 with a uniform distance 8 over the entire front side 6 of the honeycomb body 7. In the case shown here, the heating device 2 is fitted with a single heating wire 3, which spans the front side 6 of the honeycomb body 7 (completely) in a meandering shape. Here, two electrodes 15 are provided opposite one another to enable the current to be passed in and out through the housing 16 (in an electrically insulated manner). Via these electrodes 15, the heating wire 3 is connected, for example, to a power supply unit (not shown here) or the electric ground.

[0037] FIG. 2 shows a preferred variant of a heating wire 3, which is embodied in the manner of a coaxial cable. Provided in the middle or centrally in this variant is the electrically conducting wire core 22, which forms a wire core cross section 28. The wire insulation 9 is provided in such a way as to surround this wire core 22 coaxially in the manner of a hollow cylinder. A metallic wire sheath 23 is provided over the sheath and completely surrounding it, once again coaxially. This construction is preferably implemented fully between the two electrodes of the heating device. It is likewise apparent from FIG. 2 that the (outer) wire cross section is of oval design and thus forms a maximum and a minimum wire diameter 4.

[0038] FIG. 3 shows a detail of a variant embodiment of a pin arrangement 5, wherein two different pins 11 are illustrated here by way of example, although this is not absolutely necessary in a pin arrangement 5. The end region of the pins 11, which is illustrated at the bottom here, is positioned in such a way that the pins 11 are secured in the honeycomb body 7, namely projecting into cavities 12 starting from the front side 6. For this purpose, use is made, in particular, of a joint 24, e.g. by means of a brazing material, especially if the pins 11 and the honeycomb body 7 are of metallic design in the region. To ensure that the heating wire 3 indicated here is now fixed permanently at the predetermined distance 8 from the front side 6 of the honeycomb body 7, the pins 11 have pin passages 14, in which the heating wire 3 is guided or held. In the left-hand configuration of the pin 11, the pin passage 14 is provided in the form of a (closed) eye, while the pin 11 illustrated on the right forms a pin passage 14 in the form of a hook or a loop, in which the heating wire 3 is received. The fixing of the heating wire 3 relative to the pins 11 is also achieved by means of a separate clamping element 27 (here in the form of a clamping screw, for example). However, a material joint between the (metallic) pin 11 and the (externally metallic) heating wire 3 is preferable under some circumstances.

[0039] Merely for the sake of completeness, it may be noted that it is not a complete section of the honeycomb body 7 which is shown here but only a partial region close to the front side 6. Here, the cavities 12 are formed, in particular, by metal layers 21, e.g. in the form of structured and/or smooth metal foils.

[0040] To illustrate the area of application, a motor vehicle 18 is furthermore shown in FIG. 4, the vehicle comprising an internal combustion engine 25 and a downstream exhaust gas aftertreatment system 19. The honeycomb body arrangement 1 proposed here, having a plurality of electric heating devices 2, is incorporated into this exhaust gas aftertreatment system 19, wherein the heating devices are once again supported against a downstream honeycomb body 7. The motor vehicle 18 furthermore has a control unit 20, by means of which power may be fed from a power supply unit 17 to the plurality of electric heating devices 2 as required, optionally on the basis of measured values and/or operating modes of the internal combustion engine 25.

[0041] In particular, the concept proposed here of a honeycomb body arrangement having an electric heating device allows incorporation into a 48V onboard electrical system of a motor vehicle, according to which an electrical resistance in a range of from 0.5-5 ohms is provided by the at least one heating wire. Precisely in the case of a heating wire of coaxial construction with an external metallic wire sheath, the pin arrangement is soldered directly to the heating wire, thereby simplifying production. Moreover, this concept allows heat input by heat conduction to the (coated) honeycomb body, thus making possible a rapid start of conversion. In particular, it is thereby also possible to set particularly low heat outputs (by virtue of the relatively high electrical resistance).

[0042] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.