EP3004758A1

EP3004758A1 - Domestic refrigeration device comprising a wall having a multi-layer structure and method for producing a multi-layer structure

Info

Publication number: EP3004758A1
Application number: EP14729271.8A
Authority: EP
Inventors: Frank Bailly; Andreas Kleiner; Jörg STELZER
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2013-06-06
Filing date: 2014-06-03
Publication date: 2016-04-13
Also published as: WO2014195298A1; DE102013210484A1

Abstract

The invention relates to a domestic refrigeration device (1), comprising an interior (5, 6) for accommodating foods, which is bounded by walls, at least one wall having a multi-layer structure (13), which comprises at least one first deformable thermally insulating layer (14) made of a first thermally insulating material, the first thermally insulating layer (14) being formed having at least two different thicknesses (d1, d2, d3) in the structure (13), wherein the multi-layer structure (13) has at least one second deformable thermally insulating layer (20) made of a second thermally insulating material that is softer than the first thermally insulating material, the second thermally insulating layer (20) being arranged in the structure (13) in the region (II) in which the first insulating layer (14) has the smaller thickness (d2). The invention further relates to a method for producing a wall that bounds an interior (5, 6) of a domestic refrigeration device (1).

Description

Domestic refrigeration appliance with a multi-layered wall and method for producing a multilayer structure

The invention relates to a household refrigerator with an interior for receiving food, which is limited by walls. At least one wall has a multilayer construction. This multilayer structure comprises at least a first deformable thermal insulation layer of a first thermally insulating material. The first thermal insulation layer is formed with at least two different thicknesses in the structure. Furthermore, the invention relates to a method for producing a wall defining an interior of a domestic refrigerator, which is formed with a multi-layered structure.

Domestic refrigerators, such as refrigerators, freezers or refrigerated combined freezers usually include an inner container, which limits with its walls an interior in which the food for storage and preservation are introduced. This inner container is usually surrounded by an outer housing, wherein at least one thermal insulation material is introduced in an intermediate space between this outer housing and the inner container. By the outer casing and the inner container and the insulating material mounted therebetween, a multilayer structure of a respective wall defining the inner space is formed.

In the context, it is known that such thermal insulation materials can be foams. In addition, vacuum insulation panels are also known, which can be introduced in such a space in addition to or instead of the foam material.

Since these walls bounding the interior may also be designed to be uneven, in particular on the sides facing the interior, the gap is then correspondingly designed to be unevenly thick. Such desired and defined unevenness on an inner side can preferably be used to secure compartment space divider on the vertical sides. On a door, which is also understood as a wall to limit the interior, such bumps can be used to attach door cabinets. Through this desired unevenness, which define and form by depressions in these insides of the wall, the gap is narrowed at these points, as it were. The introduced thermal insulation material is therefore thinner at this point than at locations in the intermediate space at which no such depressions or desired unevennesses are provided on the inside of these walls. Especially in the case of foams, but also, for example, in the case of aerogels, the effect occurs during manufacture that the material shrinks. This shrinkage also depends, in particular in the case of foams, essentially on how the respective material thickness of the foam is formed. Thus, a greater shrinkage in the areas can be seen, in which this insulation material thickness is greater than other areas. Even if a relatively discrete transition between a thicker and a thinner area is formed, which is given by the relatively stepped configuration of the transition from the normal inner side to such a recess, a relative abrupt increment of this insulating material also occurs. Especially in this transition region then forms an undesirable deformation of the inside of a wall bounding the interior during the shrinkage process of the insulation material, so that this no longer flat, but is deformed undesirable curved.

This may result in disadvantages in the attachment of other components on these insides, so that possibly the introduction and stable holding of partitions or door compartments may be affected. Also, by these undesirable deformations gives a poor quality impression, which is also to be avoided.

It is an object of the present invention to provide a household refrigerating appliance, in which such undesirable, visible on an inner side of an interior wall bounding bumps are prevented. It is also an object to provide a method for producing a wall bounding an interior space of a household refrigerating appliance, in which correspondingly such undesired unevenness is prevented.

These objects are achieved by a household refrigerator and a method according to the independent claims. An inventive household refrigerator comprises an interior for receiving food, which is limited by walls. At least one such wall has a multilayer structure which comprises at least a first deformable thermal insulation layer of a first thermally insulating material. The first thermal insulation layer is formed with at least two different thicknesses in the structure. An essential idea of the invention is to be seen in that the multilayer construction has at least one second deformable thermal insulation layer made of a second thermally insulating material softer to the first thermally insulating material. The second thermal insulation layer is disposed in the region in which the first insulation layer has the smaller thickness. Thus, a layer structure is formed in which an additional material component different from the first thermal insulation material is added at very locally specified locations. In addition, this additional material component is specified in terms of its properties in comparison to the first material in that it is softer of the composition and of the structure with regard to force effects or deformations than the first thermally insulating material. By means of such a configuration it is achieved that owing to the different shrinkages of the first thermal insulating material, the formation of undesired unevenness is at least significantly reduced precisely at the points where a thickness variation of the first material occurs.

It is preferably provided that the second thermally insulating material is a flexible foam. In particular, soft foam is a soft foam made of polyester. In addition, flexible foam panels made of polyurethane are possible.

In particular, it is provided that the material thickness of the second insulation layer is substantially the same at all points. However, it can also be provided that the thickness of this second insulation layer varies locally. Depending on the thickness configuration of the first insulation layer and in particular the shape of the transitions between two different thicknesses of this first thermal insulating material, the thickness configuration of the second insulation layer can be formed depending on the situation and needs. It is preferably provided that the second insulation layer has a thickness between 1 mm and 5 mm, in particular between 2 mm and 3 mm. Such material thicknesses of this second insulating layer in particular satisfy the requirements resulting from the thickness variation of the first insulating layer to prevent unwanted deformations of the visible inner side of the wall at the transitions between the thicknesses of the first insulating layer.

In particular, it is provided that the first insulation layer is thicker than the second insulation layer. In this context, even relatively thin second insulation layers are sufficient to prevent or compensate for the aforementioned disadvantageous effect of the shrinkage differences at different thicknesses of the first insulation layer. As a result, the thickness of the wall is not unnecessarily increased, so that the useful volume of the interior is not restricted.

It is preferably provided that the first insulating layer in the region with its smaller thickness is threefold thicker than the second insulating layer. This again makes it clear that the desired effect is achieved with a very thin second insulating layer, on the other hand seen that the first insulating layer can then be formed with the largest possible smaller thickness, so that here the thermal insulation effect is not undesirably reduced.

It is preferably provided that the second insulating layer is arranged closer to the inner space in the structure than the first insulating layer. As a result of this configuration, the immediate vicinity of the second insulation layer is virtually produced toward the inside, whereby the functionality of the second insulation layer is then also improved and improved, so that no undesired bumps are formed on the visible inner side of the wall.

It is preferably provided that the first insulating layer is at least partially formed as rigid foam, in particular polyurethane.

It is advantageously provided that the first insulating layer is formed at least partially from airgel. In particular, it is provided that the thickness of the first insulating layer in a cross section changes at least twice, in particular changes from a first larger thickness to a second smaller thickness and then again to a greater thickness. Such a thickness jump, which represents a groove-like depression, can be used for example for receiving door racks in a door or for receiving dividers on vertical side walls. In particular, the second insulating layer is applied only in the region of the second smaller thickness of this cross-sectional contour. In particular, it is provided that this second insulation layer is formed and arranged over its entire area in this area with the second smaller thickness. The advantages mentioned above are thereby further favored.

It is preferably provided that the multilayer construction is produced such that it is arranged in a foam mold during production and the foam mold has an uneven contact surface or molding surface at the region where the first insulation layer has a smaller thickness. By such a configuration, the unwanted effect of the different shrinkage in the transition between different thicknesses of the first insulating material is already counteracted by the mold itself. The uneven abutment surface may be shaped to be oriented away from the multi-layered structure to transition to the region of greater thickness of the first insulating layer. Additionally or instead, it may also be provided that this uneven contact surface is formed at the transition of the thickness variation of the first insulating layer away from the transition in the direction of the region with the thicker thickness of the first insulating layer oriented away from the structure. Thus, by a specific shaping of the inside of the foam mold, which then also faces with the material which results in the multi-layered layer structure, defined. In particular, the actual shaping and structuring depends on the respective configuration of the multilayer construction. Furthermore, the invention relates to a method for producing a wall delimiting an interior of a domestic refrigerator, which is formed with a multilayer structure having at least one first deformable thermal insulation layer of a first thermally insulating material. The first thermal Insulation layer is formed with at least two different thicknesses in the structure. The multilayer structure is formed with at least one second deformable thermal insulation layer made of a second thermally insulating material which is softer than the first thermally insulating material. The second thermal insulation layer is formed in the region in which the first insulation layer has the smaller thickness.

Advantageous embodiments of the household refrigerator according to the invention are to be regarded as advantageous embodiments of the method according to the invention. Walls delimiting an interior are given in particular by vertical opposite side walls, a rear wall, a ceiling wall, a bottom wall and by a front door. Each of these specified walls, taken as such, should be understood as a continuous plate-like structure, in each of which such a multi-layered construction is designed with at least a single thickness variation of the first thermal insulation layer.

By the foaming mold and in particular its inside, which faces the material from which the structure is to be formed, a kind of negative mask is virtually formed, which is adapted to the known and expected different degree of shrinkage at the transition of the different thicknesses of the first insulating material. By such a configuration is achieved in particular without additional additional material addition to the layer structure in the manufacturing process by the tool itself that undesirable deformations on the inside arise due to unwanted curvatures of the inside in the thinner first insulation layer in particular in the area at the transition of greater thickness first insulation layer arise.

It is preferably provided that in the region to be produced with the thinner thickness of the first insulating layer, the foaming mold is provided with a protrusion. As a result of this specific design of the unevenness of the contact surface, the level at which the final shrinkage is to take place is virtually predetermined. The survey can be formed as a flat surface. In this embodiment, it is then further advantageous that the survey is formed adjacent to the flat surface in concave curved contact surface areas. The flat surface then preferably extends over the dimensions in which the thinner thickness of the first insulating material is provided, and by the then relatively gentle, not discretely stepped transition of the unevenness of the contact surface but by concave curved transitions, the shrinkage behavior at the transition of the different Thickness of the first insulating material advantageously influenced accordingly, so that after completion of the shrinking process, the desired final shape of the inside of the wall is formed and here according to the individual generated inner side surface areas this is then designed as flat as possible.

It is preferably provided that in another embodiment, the elevation is formed as a convexly curved dome. In particular, this convexly curved dome, which is correspondingly convex in cross-section, extends beyond the dimensions of the region in which the first insulating layer is formed with a thinner thickness. By the shape of this survey is realized to the edge or towards the ends, which is remote from the structure or is formed oriented away from the structure, here also the desired shape of the inside in the final shape of the wall is taken into account. It can be provided that the elevation of the contact surface is integrated in the foam mold or designed as an additional separate insert, which is then introduced and secured accordingly.

In particular, the convex contour is formed such that the points of the transition region between the thicknesses of the first insulation layer are defined by their ends or edges. This convex contour thus ends with the ends and edges exactly at the points where the transition between the thinner thickness to the greater thickness of the first insulating layer is then to occur. By also provided here, not discrete, but continuously changing survey here the shrinkage behavior is taken into account in the transition area and adapted accordingly, so that here, a corresponding compensation can be realized. In particular, the shape and depth of the unevenness of the abutment surface is dependent on the difference in thickness of the first insulating layer at the transition between the smaller and the larger thickness and / or the absolute thickness of the first insulating layer.

It is preferably provided that the multilayer structure with at least one second deformable thermal insulation layer is formed from a second thermally insulating material which is softer than the first thermally insulating material. The second thermal insulation layer is formed in the region in which the first insulation layer has the smaller thickness.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and feature combinations mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination but also in other combinations or in isolation, without the frame to leave the invention. Thus, embodiments of the invention are to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, however, emerge and can be produced by separated combinations of features from the embodiments explained. Embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

Fig. 1 is a perspective view of an embodiment of a household refrigerator according to the invention;

Fig. 2 is a longitudinal sectional view through the household refrigerator of FIG. 1;

Fig. 3 is a horizontal sectional view of the door of the household refrigerator according to

Fig. 1;

Fig. 4 is an exploded view of an embodiment of a multilayer structure of a wall which defines an interior of the household refrigerator 1, the illustration in Fig. 4 at a such location is shown, on which a first insulating layer of this construction has a relation to other areas smaller thickness;

Fig. 5 shows another embodiment of a multilayer structure of a

Interior limiting wall in the area in which a smaller thickness of the first insulating layer is provided, wherein in addition an embodiment of a specific shape of a foaming mold is shown; and

Fig. 6 shows a further embodiment in comparison to Fig. 5, in which the

Embodiment of the foaming mold is different.

In the figures, identical or functionally identical elements are provided with the same reference numerals. In Fig. 1, a household refrigeration appliance 1 is shown in a perspective view, which may be designed as a refrigerator or freezer or fridge-freezer combination device.

The household refrigerating appliance 1 comprises an outer casing 2, which surrounds inner containers 3 and 4, which may be designed as separate inner containers or in one piece. The inner container 3 defines a first inner space 5, and the inner container 4 defines a second inner space 6. The two inner spaces 5 and 6 are provided for receiving food. The interiors 5 and 6 are each bounded by side walls, rear walls, floors and ceilings of the inner container 3 and 4. On the front side, the inner containers 3 and 4 have a loading opening, which can be closed by a door 7.

The inner container 3 comprises the walls 3a, 3b, 3c and 3d, whereas the inner container 4 has the walls 4a, 4b, 4c and 4d. The door 7 is in the sense of a wall that defines the interiors 5 and 6. Between the inner container 3 and the outer housing 2, a gap 8 (FIG. 4) is formed, in which thermally insulating material is introduced. Likewise, a correspondingly thermally insulating material is introduced in a corresponding intermediate space 8 between the inner container 4 and the outer housing 2. In Fig. 2, the household refrigerator 1 without the door 7 is shown on the front. The gaps 8 can be seen in this illustration in section (xy plane) as well.

As can be seen in the context, is formed between the inner containers 3 and 4 in a horizontal direction and thus in the x-direction considered area in which an introduced thermal insulation material in the form of a self-shrinking in the production material is thicker than at the Positions in which the inner container 3 and 4 are arranged and positioned at a distance from the outer container 2. Since such shrinkage processes occur in such thermal insulation materials as insulation foams and aerogels, and this shrinkage occurs depending on the respective prevailing material thickness of the thermal insulation material, undesired deformations occur precisely at these corresponding points according to the prior art, which are then deformed on the insides of the Interiors 5 and 6 delimiting walls 3a to 3d and 4a to 4d and 7 can be seen.

For this purpose, an enlarged representation of a horizontal section and thus of the section in the xz plane of the door 7 is shown in FIG. The door 7 also comprises an inner end part 9, which thus faces the inner space, and an outer end part 10, which form the shell, as it were. In the intermediate space 8 between the parts 9 and 10 is also at least partially a thermally insulating material, such as an insulating foam or an airgel. In this connection, it can be seen that a thickness d 1, which represents the thickness of the thermally insulating material, is greater in a region I than in a region II in which the thickness is only d 2. In a subsequent region III, the thickness d3 is given, which in turn is greater than the thickness d2. At the transition areas 1 1 and 12, in which the thickness variation changes relatively abruptly, occur in particular the Appearances of the different shrinking operations, so that in the state of the art in a final state, the inner end part 9 in the region II has a convexly curved shape.

In order here, as shown in Fig. 3, in the region II in particular in the final part 10 to achieve as flat a design of the contour, a according to an embodiment in Fig. 4 shown multilayer structure 13 is formed. In this context, it is provided that only in an area II of this door formed as a wall a correspondingly shown in the representation in Fig. 4 shown, multi-layer structure is formed. In this context, a first thermal insulation layer 14 of a first thermally insulating material, for example of an insulation foam or airgel, is arranged between the closure part 10 and the closure part 9. This insulation layer 14 is attached to the termination part 10 via an adhesive layer 15. In addition, a further adhesive layer 16 is provided, with which the first insulation layer 14 is fastened to the termination part 9. In order to be able to at least significantly reduce, in particular prevent, the undesired deformation in region II already explained in connection with FIG. 3 during production and in particular the subsequent shrinkage of the insulating material of layer 14, it may be provided that a foaming mold 17, as shown in FIG. 5 is designed specifically. In this connection, the foam mold 17 has a carrier 18 on which an insert 19 is arranged. The insert 19 is uneven on its side facing the material for the layer structure 13 side 19a. In the embodiment, it is provided that a convex curvature is formed. This convex curvature profile of the inner side 19a terminates with ends 19b and 19c preferably exactly at the locations where the transitions 1 1 and 12 are provided in the finished state. By means of this specifically formed foam mold 17 with the insert 19, during the manufacture of the door 7 and the introduction of the materials of the insulating material and of the adhesive into the foam mold 17, a preforming or setting is achieved by means of which during the subsequent curing of the insulation material, in which case Transitions 1 1 and 12 and the associated thickness variations of the insulation material different degrees of shrinkage go along, unwanted deformations of the end part 9 can be compensated. By this foaming mold 17, it is thus possible that already in the manufacturing process on the expected degree of shrinkage at the areas of Transitions 1 1 and 12 takes place a pre-compensation, so that then in the cured or when terminating the shrinkage, a desired shape, as shown in Fig. 3, is achieved. A thus undesirable, in particular convex deformation of the region II is thereby virtually prevented. In Fig. 5, another embodiment of a multilayer construction 13 is shown. In contrast to the embodiment according to FIG. 4, in which the foaming mold 17 is then present and designed accordingly, an additional second insulating layer 20 is provided in the exemplary embodiment in FIG. 5, which is arranged in particular directly following the first insulating layer 14. As can be seen from the representation in FIG. 5, this second thermal insulation layer 20 made of a second thermal insulation material is thinner than the first insulation layer 14. The thickness of the second thermal insulation layer 20 is preferably between 1 mm and 5 mm, in particular between 2 mm and 3 mm. The material of the second thermal insulation layer 20 is preferably flexible foam, in particular flexible polyurethane foam.

The material of the first thermal insulation layer 14 may be formed as rigid foam or airgel. In this embodiment according to FIG. 5, in which again this second thermal insulation layer 20 is formed only in the region II, and in the regions I and III this second thermal insulation layer 20 is not present, a compensation of due to different degrees of shrinkage is likewise provided associated undesirable deformations in the area II or in the areas at the transitions 1 1 and 12 reached.

In addition, in the exemplary embodiment according to FIG. 5, it may also be provided that in addition to the introduction of this second thermal insulation layer 20, the foaming mold 17 according to the explanation of FIG. 4 is additionally provided in the production. In addition to the introduction of the further insulating layer 20 can be counteracted even during the manufacturing process by the foam mold 17 and the insert 19 of this undesirable deformation in the region of the transitions 1 1 and 12. FIG. 6 shows a further exemplary embodiment in which an alternative embodiment of the foam mold 17 is formed in comparison to the representation in FIG. 5 and according to the use also for the exemplary embodiment in FIG. 4. In this embodiment, the foam mold 17, which is designed in particular in one piece, an uneven shape of the material of the layer sequence to be designed, as given by the multilayer structure 13, facing side 17a in particular a trapezoidal shape in cross-section, formed. Thus, in the longitudinal section, in which then the area II is to be formed, a survey 21 is formed, which has a flat side 21 a over the entire extent of the region to be generated II. This contact surface or shape specification surface of this page 21 a is thus designed flat. At the points where then the transitions 1 1 and 12 to the areas I and II I arise, the survey ends 21 and the side 17 a then falls off to the side in a curved, in particular concave shape. The survey 21 in Fig. 6 corresponds in terms of functionality and the insert 19. This insert 19 is thus to be seen as a survey.

In the foam molds 17, as shown and explained in the alternative embodiments, thus a production is possible, in which for forming the shape of the structure 13, the material is introduced and the foam mold 17 at a transition region 1 1, 12, in which a Thickness change of the first insulating layer 14 is formed, with an inner side 17 a provided with an uneven contact surface 21 a and 19 respectively. This unevenness is defined in a defined manner so that the outer end shape of the wall, in the present case the door 7, arises in the case of a subsequent different shrinkage of the first thermal insulation material due to the different layer thicknesses of the first insulation layer 14.

The explanations given to FIGS. 4 to 6 also apply to other walls which delimit the interior spaces 5 and 6. In this context, the walls are not understood as meaning the individual wall parts 3a to 3d and 4a to 4d of the inner containers 3 and 4, but each understood a wall formed by a multi-layered structure 13. For example, in the context of a vertical wall, the interior of the fifth limited, formed by the wall portion 3a, the layers 14, 15, 16 and 20 therein and the corresponding wall portion of the outer housing 2. The same applies to the other possible walls.

LIST OF REFERENCE NUMBERS

1 household refrigerator

2 outer housing

3 inner container

3a-d walls

4 inner container

4a-d walls

5 interior

6 interior

7 door

8 space

9 inner final part

10 outer end part

1 1 transition area

12 transition area

13 construction

14 First thermal insulation layer

15 adhesive layer

16 adhesive layer

17 foaming mold

17a page

18 carriers

19 depositors

19a inside

19b, c ends

20 Second thermal insulation layer

21 Survey

21 a page

Claims

claims

1. Household refrigeration appliance (1), with an interior space (5, 6) for receiving

Food bounded by walls, and at least one wall having a multi-layered structure (13) comprising at least a first deformable thermal insulation layer (14) of a first thermally insulating material, and the first thermal insulation layer (14) having at least two different ones Thickness (d1, d2, d3) is formed in the structure (13), characterized in that the multilayer structure (13) at least one second deformable thermal

Insulating layer (20) made of a second thermally insulating material to the first thermally insulating material, the second thermal

Insulation layer (20) in the region (II) in the structure (13) is arranged, in which the first insulating layer (14) has the smaller thickness (d2).

2. Domestic refrigerating appliance (1) according to claim 1, characterized in that the second thermally insulating material is a flexible foam, in particular flexible polyurethane foam.

3. Domestic refrigerating appliance (1) according to claim 1 or 2, characterized in that the second insulating layer (20) has a thickness between 1 mm and 5mm, in particular between

2mm and 3mm, has.

4. Domestic refrigerating appliance (1) according to one of the preceding claims, characterized in that the first insulating layer (14) is thicker than the second

Insulation layer (20).

5. Domestic refrigerating appliance (1) according to claim 4, characterized in that the first insulating layer (14) is at least 3 times thicker than the second insulating layer (20).

6. Domestic refrigerating appliance (1) according to one of the preceding claims, characterized in that the second insulating layer (20) the interior (5, 6) lying closer in the structure (13) is arranged as the first insulating layer (14).

7. Domestic refrigerating appliance (1) according to one of the preceding claims, characterized in that the first insulating layer (14) at least partially

Hard foam, in particular polyurethane, is formed.

8. Domestic refrigerating appliance (1) according to one of the preceding claims, characterized in that the first insulating layer (14) is formed at least partially from airgel.

9. Domestic refrigerating appliance (1) according to one of the preceding claims, characterized in that the thickness of the first insulating layer (14) viewed in a cross section changes at least twice, in particular from a first larger thickness (d 1) to a second smaller thickness (d2 ) and then again to a greater thickness (d3) changes, and the second insulating layer (20) only in the region (II) with the second smaller thickness (d2) is mounted, in particular over the entire area of the second area (II) attached there.

10. domestic refrigeration appliance (1) according to one of the preceding claims, characterized in that the structure (13) is formed so that it is arranged in the production in a foaming mold (17) and the foaming mold (17) at the area (II) in which the first insulation layer (14) has a smaller thickness (d2) has an uneven abutment surface (17a), in particular to the transition (1 1, 12) to the region (I, I II) with the greater thickness (d1, d3) the first insulating layer (14) oriented away from the structure (13) is oriented, and / or the contact surface (17a) at the transition (1 1, 12) of the thickness variation of the first insulating layer (14) from the transition (1 1, 12) away in the direction of the region (I, II I) with the greater thickness (D1, d3) of the first insulating layer (14) from the structure (13) oriented away shaped.

1 1. Method for producing a wall delimiting an interior space (5, 6) of a household refrigerating appliance (1), which has a multilayer structure (13) with at least one first deformable thermal insulation layer (14) made of a first material is formed insulating material, and the first thermal insulation layer (14) having at least two different thicknesses (d1, d2, d3) in the structure (13) is formed, characterized in that the multilayer structure (13) with at least one second deformable thermal Insulation layer (20) is formed of a second thermally insulating material softer to the first thermally insulating material, and the second thermal insulation layer (20) is produced in the region (II) in the structure (13) in which the first insulation layer (14) has smaller thickness (d2).