Exhaust gas aftertreatment device having small cavities

A device for aftertreatment of exhaust gases from an internal combustion engine, comprising:

• at least one first casing;
• a honeycomb body through which a flow can pass along a main flow direction from a gas inlet side to a gas outlet side;
• a ceramic mat and with at least one first casing that receives the honeycomb body, wherein the ceramic mat is arranged between the honeycomb body and the at least one first casing and surrounds the honeycomb body as a ring in a peripheral direction,
• wherein the ceramic mat is configured such that a cavity formed between the honeycomb body and the at least one first casing is completely filled by the ceramic mat;
• and
• a second casing in which the honeycomb body is received, and the second casing is surrounded by the ceramic mat as a ring in the peripheral direction,
• wherein the second casing has, at an end region facing a gas inlet side, a portion having a structure which is different from a remainder of structure of the second casing,
• wherein the second casing has openings in the portion which are arranged spaced apart from one another on the gas inlet side.

A device for aftertreatment of exhaust gases from an internal combustion engine, comprising:

• at least one first casing;
• a honeycomb body through which a flow can pass along a main flow direction from a gas inlet side to a gas outlet side;
• a ceramic mat and with at least one first casing that receives the honeycomb body, wherein the ceramic mat is arranged between the honeycomb body and the at least one first casing and surrounds the honeycomb body as a ring in a peripheral direction,
• wherein the ceramic mat is configured such that a cavity formed between the honeycomb body and the at least one first casing is completely filled by the ceramic mat;
• and
• a second casing in which the honeycomb body is received, and the second casing is surrounded by the ceramic mat as a ring in the peripheral direction,
• wherein the second casing has, at an end region facing a gas inlet side, a portion having a structure which is different from a remainder of structure of the second casing,
• wherein the portion of the second casing on the gas inlet side is made from a material different from the remainder of the second casing, wherein the different material has a significantly reduced thermal capacity.

A method for producing a device for aftertreatment of exhaust gases, comprising:

• providing a second casing having at an end region facing a gas inlet side, a portion having a structure which is different from a remainder of structure of the second casing, wherein the portion has a lower thermal capacity than the remainder of the structure;
• inserting a honeycomb body in the second casing;
• inserting the honeycomb body and the second casing in a ceramic mat;
• inserting the ceramic mat and the second casing with the honeycomb body in a first casing;
• and
• exerting at least a radially acting force on the first casing, the ceramic mat and/or the honeycomb body.