The subject matter of the invention is a device and a method for connecting housing sections for soot particle filters, as well as a clamping U-bolt.
In the case of vehicles with combustion engines, filters and catalytic converters are being used to an increasing degree for treating exhaust gases. In this way, the environmental load due to pollutants such as soot particles, hydrocarbons, carbon monoxide, or nitrogen oxides can be greatly reduced. For treating diesel exhaust gases, catalytically active soot particle filters are also known in which soot particles are first held on the filter surface and then—when the temperature is sufficiently high—converted catalytically. As a rule, filters and catalytic converters comprise a ceramic carrier or monolith that is provided with a so-called wash coat making the surface larger. This monolith is held in a metallic housing or the so-called canning that is installed rigidly in the exhaust-gas line.
In the case of diesel particle filters, as a rule the combustion of the particles does not take place completely without residue. Over time, additives contained in motor oil and in diesel fuel can lead to ash deposits in the filter. Metal wear debris in the engine likewise leads to the formation of ash. This increases the exhaust gas back pressure of the filter and thus the fuel consumption. Soot particle filters therefore must be regularly serviced or cleaned, e.g., annually or after reaching a predetermined number of miles traveled. For this purpose, soot particle filters must be separated from the exhaust-gas line and can be reattached after cleaning.
From DE 20012812 U1, an exhaust-gas cleaning device is known with a housing constructed from several cylindrical modules in which a filter unit is installed in at least one of these modules. The individual modules can be placed one in the other or joined to each other by flange-like fastening elements. In the case of metallic housings, the modules are welded for mutual attachment. Because the housing modules are welded to each other, the filter unit can be removed only when the housing is separated. Even without welding, flanges that project outward on the housing take up a lot of space. In the case of housing modules pushed one inside the other, space and play for movements are likewise required in the direction of the housing axis, so that the individual modules can be separated from each other.