Provided is an exhaust gas purification device provided with a cover which can reduce radiated noise at low cost without impairing the heat shield function of the cover. Provided is an exhaust gas purification device comprising: an exhaust gas purification device body provided to the exhaust pipe of a diesel engine and purifying exhaust gas; and a substantially rectangular cover provided so as to cover at least a part of the exhaust gas purification device body and blocking heat radiated from the exhaust gas purification device body. The cover is provided with a plurality of protruding ribs formed on the surface thereof. The ribs comprise: radial ribs formed extending radially from a center section centered at the intersection of the diagonals of the cover; and a circumferential rib formed continuously along the entire circumference of a circle centered at the intersection.

Provided is an exhaust gas purification device provided with a cover which can reduce radiated noise at low cost without impairing the heat shield function of the cover. Provided is an exhaust gas purification device comprising: an exhaust gas purification device body provided to the exhaust pipe of a diesel engine and purifying exhaust gas; and a substantially rectangular cover provided so as to cover at least a part of the exhaust gas purification device body and blocking heat radiated from the exhaust gas purification device body. The cover is provided with a plurality of protruding ribs formed on the surface thereof. The ribs comprise: radial ribs formed extending radially from a center section centered at the intersection of the diagonals of the cover; and a circumferential rib formed continuously along the entire circumference of a circle centered at the intersection.

An exhaust-gas aftertreatment device for an internal combustion engine, for use in a motor vehicle, includes an exhaust tract with at least one exhaust pipe and at least one exhaust-gas aftertreatment element. The exhaust-pipe internal wall and/or the at least one exhaust-gas aftertreatment element have/has a vapor-sorbing material forming at least one exhaust-tract-side sorption element.

An exhaust-gas aftertreatment device for an internal combustion engine, for use in a motor vehicle, includes an exhaust tract with at least one exhaust pipe and at least one exhaust-gas aftertreatment element. The exhaust-pipe internal wall and/or the at least one exhaust-gas aftertreatment element have/has a vapor-sorbing material forming at least one exhaust-tract-side sorption element.

An exhaust gas heating arrangement includes a heating unit having a jacketed heating element having a jacket and at least one heating conductor which extends in the jacket and is surrounded by insulating material. The heating unit is spirally wound surrounding a longitudinal center axis (L), wherein a radially inner winding end region of the heating unit is offset with respect to a radially outer winding end region of the heating unit in the direction towards the longitudinal center axis (L).

An exhaust gas heating arrangement includes a heating unit having a jacketed heating element having a jacket and at least one heating conductor which extends in the jacket and is surrounded by insulating material. The heating unit is spirally wound surrounding a longitudinal center axis (L), wherein a radially inner winding end region of the heating unit is offset with respect to a radially outer winding end region of the heating unit in the direction towards the longitudinal center axis (L).

A honeycomb structure has a pillar-shaped honeycomb structure body having porous partition walls which defines cells which forms a passage of liquid extended from an inflow end face toward an outflow end face, a circumferential wall arranged to surround a circumference of the partition walls. The honeycomb structure body has an outermost circumference cell structure including a complete cell arranged at the outermost circumference of the honeycomb structure body, a center cell structure formed by the cells arranged at a center part at an inner side to the outermost circumference cell structure, and a boundary wall arranged at a boundary part between the outermost circumference cell structure and the center cell structure. The outermost circumference cell structure and the center cell structure are formed as different structures to each other, and a thickness of the boundary wall is set to be thicker than a thickness of the circumferential wall.

A heat-insulated pipe assembly includes a pipe allowing a fluid to flow therethrough, and a heat insulating member covers at least a part of the pipe. The pipe is used in an exhaust gas purification system using an SCR catalyst. The heat insulating member has a closed-cell structure and suppresses an increase in a temperature of the fluid due to heat exchange with air. In the exhaust gas purification system using the SCR catalyst, the interior of the pipes is thermally insulated from the exterior by the heat insulating member. Thereby an increase in the temperature of the fluid flowing through the pipe due to heat exchange with air is suppressed.

A heat-insulated pipe assembly includes a pipe allowing a fluid to flow therethrough, and a heat insulating member covers at least a part of the pipe. The pipe is used in an exhaust gas purification system using an SCR catalyst. The heat insulating member has a closed-cell structure and suppresses an increase in a temperature of the fluid due to heat exchange with air. In the exhaust gas purification system using the SCR catalyst, the interior of the pipes is thermally insulated from the exterior by the heat insulating member. Thereby an increase in the temperature of the fluid flowing through the pipe due to heat exchange with air is suppressed.

A chemical heat storage device includes a reactor disposed around an oxidizing catalyst and containing MgCl.sub.2 which chemically reacts with NH.sub.3 to generate heat, a storage connected to the reactor through a pipe to store NH.sub.3, an on-off valve disposed in the pipe, a temperature sensor detecting the temperature of the exhaust gas passing through the oxidizing catalyst, and a controller controlling the on-off valve based on the detected value of the temperature sensor. The controller controls the on-off valve such that the on-off valve unconditionally opens if the temperature of the exhaust gas is greater than a heat generating start temperature T.sub.L and is equal to or less than a heat generating end guide temperature T.sub.Q, and the on-off valve unconditionally opens if the temperature of the exhaust gas is greater than a regenerating temperature T.sub.H.