Support structure for heating substrate

Abstract

The invention relates to a support structure (1) for positioning a heating substrate in an exhaust section spatially delimited by a housing, the heating substrate being formed from a honeycomb body having a plurality of flow channels through which a flow can flow in a main flow direction, the heating substrate being supported by the support structure (1) relative to an inner surface of the housing, according to the invention, the base body is fixed relative to the support structure (1) by means of a plurality of coupling elements, the support structure (1) is designed in multiple parts, the support structure (1) has at least one central ring element (3) and a plurality of struts (2), the struts protrude from the ring element (3) in the radial direction and extend towards the inner surface of the housing, and all the components are optionally connected by a joining method.

Description

Field of the Invention

[0001] The present invention relates to a support structure for positioning / arranging a heating substrate in an exhaust section spatially delimited by a housing, wherein the heating substrate is formed by a honeycomb body having a plurality of flow channels that can be flowed through along the main flow direction, wherein the heating substrate is supported relative to the inner surface of the housing by the support structure, and the substrate is fixed relative to the support structure by means of a plurality of coupling elements. Background Art

[0002] In order to heat the exhaust gas in the exhaust section downstream of an internal combustion engine or the exhaust gas flowing in the exhaust section, electric heating elements are nowadays commonly used. Here, the aim is to reach a temperature threshold more quickly, above which the harmful substances carried in the exhaust gas can be converted more effectively. This is necessary because the catalytically active surface for exhaust gas aftertreatment of a catalytic converter installed in the exhaust section can only achieve sufficient conversion of the corresponding harmful substances above a minimum temperature, i.e., the so-called light-off temperature.

[0003] Known solutions in the prior art include so-called heated catalytic converters, which have a metal structure connected to a voltage source or a ceramic structure with a metal coating that can be heated using ohmic resistance.

[0004] The heatable metal structure can, for example, include a honeycomb body made of metal foil. For this purpose, a plurality of smooth and / or at least partially structured metal foils are stacked together and wound around at least one winding mandrel to form a honeycomb body. The substrate formed by the metal foil can be electrically contacted and heated using ohmic resistance.

[0005] For this purpose, the substrate must be arranged in the exhaust section and be located upstream or downstream of a catalytic converter designed for exhaust gas aftertreatment in the flow direction of the exhaust gas.

[0006] In order to position and support the substrate in the exhaust section and, in particular, to resist mechanical and thermal loads, a bracket must be provided, which in particular can withstand the high thermal cyclic loads and strong and irregular mechanical loads in the exhaust section, especially in the exhaust section of a motor vehicle.

[0007] The disadvantages of the known solutions in the prior art are, in particular, that the structure is very complexly constructed and thus its cost is not optimal. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide a support structure for a heating substrate for spatially positioning the heating substrate in an exhaust section, which support structure has a simple construction and improved performance in terms of support against mechanical and thermal disturbance variables.

[0009] The object related to the support structure is achieved by a support structure having the features of claim 1.

[0010] Embodiments of the present invention relate to a support structure for positioning a heating substrate in an exhaust section spatially defined by a housing, wherein the heating substrate is formed by a honeycomb body having a plurality of flow channels that can be flowed through along a main flow direction, wherein the heating substrate is supported relative to the inner surface of the housing by the support structure, and the substrate is fixed relative to the support structure by means of a plurality of coupling elements, wherein the support structure is designed in a multi-piece manner, wherein the support structure has at least one central annular element and a plurality of struts that project radially from the annular element and extend towards the inner surface of the housing.

[0011] The support structure is especially for permanently positioning the heating substrate in the housing of the exhaust section. The support structure must be able to withstand vibrations and thermal loads and reliably fix the heating substrate in the housing. Since the heating substrate is energized during operation and contact with the housing must be avoided to prevent short circuits or endanger personal safety, structural failures of the support structure must be excluded.

[0012] The multi-piece structure of the support structure enables different requirements for the strength of the support structure to be optimally met. Thus, the connection of the support structure to the inner surface of the housing can be designed to be particularly stable and rigid to ensure reliable retention. However, the struts extending to the annular element must have increased elasticity to compensate for thermally induced stresses. In addition, the fixing points for the coupling elements must be arranged on the support structure such that sufficient tolerance compensation can be ensured during assembly.

[0013] If the support structure consists of multiple components, different requirements can be best met, and the multiple components may have different material properties, especially different coefficients of thermal expansion, if necessary.

[0014] It is particularly advantageous that the annular element has at least one bridging portion that connects two points of the annular element to each other. By means of such a bridging portion passing through the center or at least close to the center of the annular element, additional stability of the annular element can be achieved. In addition, such a bridging portion also provides the feasibility of arranging coupling elements in the central region of the support structure without causing excessive pressure loss of the exhaust flow here.

[0015] It is also advantageous that the annular element is formed from a blanked or laser-cut sheet. The preferred embodiment is characterized in that the struts are formed from a blanked or laser-cut sheet. The above processes make it particularly easy to produce precisely fitting components.

[0016] Also preferably, the annular element and the brace are connected to each other by one of the following permanent joining methods: laser welding, soldering or fusion welding. Especially due to the high thermal load, a joining method that can achieve a reliable and permanent connection under the given load should be selected.

[0017] Furthermore, it is advantageous that the brace is formed by a profiled sheet, wherein the section modulus / flexural section modulus of the brace in the axial direction corresponding to the main flow direction of the exhaust section is higher than that in the radial direction. Through the profiled sheet, the direction-dependent strength of the component can be achieved, so that the component can have a higher section modulus in a specific spatial direction purposefully, and thus can be customized according to the application purpose.

[0018] In addition, it is advantageous that the brace is designed in an arc shape and is evenly distributed along the circumferential direction of the housing. Multiple braces are required to reliably position the annular element. Therefore, in order to ensure a uniform force distribution, it is advantageous that the braces are arranged distributed at equal intervals from each other along the circumferential direction of the housing.

[0019] Equally suitable is that the support structure has a plurality of coupling elements, and the base is fixed to the support structure through the coupling elements, wherein the coupling elements are arranged on the braces and the central annular element. The coupling elements are used to receive the heating base and are preferably designed to compensate for tolerances.

[0020] Advantageous improvements of the present invention are described in the dependent claims and the description of the following drawings. Description of the Drawings

[0021] The present invention will be described in detail below with reference to the drawings by way of examples. Among them:

[0022] Figure 1 A view of the support structure is shown, which includes an annular element and a plurality of braces protruding in the radial direction. Detailed Description of the Invention

[0023] Figure 1 The support structure 1 is shown, which includes a centrally arranged annular element 3 and a plurality of braces 2. The annular element 3 has an S-shaped bridging portion 4 that connects two points of the annular element 3 to each other.

[0024] The braces 2 protrude radially outward from the annular element 3 and are connected at their free ends to a housing not shown or another annular element not shown either. Figure 1In the example, the braces 2 are arranged at equal intervals and arc-shaped in the circumferential direction of the annular element 3. In an alternative design, the intervals in the circumferential direction can also be different. In addition, the braces 2 can also be configured to be straight or have other shapes. In addition, additional connecting elements can be provided, for example, connecting the respective braces 2 to each other. The connecting elements can be distributed uniformly or non-uniformly and can accordingly connect two or more braces to each other.

[0025] Figure 1 The embodiments are in particular not restrictive and are used to illustrate the concept of the invention.

[0026] List of reference numerals:

[0027] 1 Support structure

[0028] 2 Brace

[0029] 3 Annular element

[0030] 4 Bridging part

Claims

1. A support structure (1) for positioning a heating substrate in an exhaust section spatially defined by a housing, wherein, The heating substrate is formed by a honeycomb body having a plurality of flow channels through which a main flow direction can pass through. Among them, the heating substrate is supported relative to the inner surface of the housing by a support structure (1), and the substrate is fixed relative to the support structure (1) by means of a plurality of coupling elements. It is characterized in that the support structure (1) is designed in a multi-piece manner, wherein the support structure (1) has at least one central annular element (3) and a plurality of struts (2), and the struts project radially from the annular element (3) and extend towards the inner surface of the housing.

2. The support structure (1) according to claim 1, characterized in that, The annular element (3) has at least one bridging portion (4) that connects two points of the annular element (3) to each other.

3. The support structure (1) according to any one of the preceding claims, characterized in that, The annular element (3) is formed by a blanked or laser-cut plate.

4. The support structure (1) according to any one of the preceding claims, characterized in that, The struts (2) are formed by a blanked or laser-cut plate.

5. The support structure (1) according to any one of the preceding claims, characterized in that, The annular element (3) and the struts (2) are connected to each other by one of the following permanent joining methods: laser welding, brazing or fusion welding.

6. The support structure (1) according to any one of the preceding claims, characterized in that, The struts (2) are formed by profile plates, wherein the section modulus of the struts (2) in the axial direction corresponding to the main flow direction of the exhaust section is higher than that in the radial direction.

7. The support structure (1) according to any one of the preceding claims, characterized in that, The struts (2) are designed in an arc shape and are evenly distributed along the circumferential direction of the housing.

8. The support structure (1) according to any one of the preceding claims, characterized in that, The support structure (1) has a plurality of coupling elements through which the substrate is fixed to the support structure (1), wherein the coupling elements are arranged on the struts (2) and the central annular element (3).

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