A motor vehicle thermal device, comprising:
- a casing perforated by an opening for access to a filter, said casing being provided with a filter trap shaped so as to seal said opening, said filter trap being made of polymer material being of planar elongated shape, having a length and having two longitudinal edges extending along the length thereof connected by two lateral edges extending along a width thereof, said trap comprising:
- a first assembly tab extending in the plane of the trap along the length thereof, said first assembly tab being fixed to a first of the two lateral edges;
- a snap-coupling configured to block said trap in a direction perpendicular to the plane of the trap, said snap-coupling being fixed to a first of the two longitudinal edges and being located closer to a second of the two lateral edges than the first of the two lateral edges, the second of the two lateral edges does not bear the first assembly tab, said snap-coupling including a fixed end that is fixed to and extends from the first of the two longitudinal edges, a free end that is opposite to the fixed end, the free end extending in the direction perpendicular to the plane of the trap, and a curved portion between the free end and fixed end;
- a second assembly tab extending in the plane of the trap in a direction perpendicular to the first assembly tab, said second assembly tab being fixed to a second of the two longitudinal edges, which does not comprise the snap-coupling, and said second assembly tab being located closer to the second of the two lateral edges than the first of the two lateral edges,
- wherein said trap is configured to have a sufficient flexibility along the length thereof to permit twisting of said trap about a longitudinal torsion axis of the trap, wherein said thermal device further comprises, on a periphery of said opening:
- means for engagement which includes an opening that the snap-coupling of the trap extends through to block the trap in a direction perpendicular to the plane thereof, and
- a first retaining tab and a second retaining tab extending in the direction perpendicular to the plane of the trap, each retaining tab defining with the casing an opening having a shape which is complementary to one of the assembly tabs of the trap, the first and second assembly tabs extending through the openings defined by the first and second retaining tabs of the casing such that the first and second assembly tabs are respectively inserted between said retaining tabs and the casing when said trap seals the opening.