DOMESTIC APPLIANCE

Abstract

A household appliance includes a receiving region and an insulation element attached to the receiving region for acoustic and/or thermal insulation of the receiving region. The insulation element is manufactured from a viscoelastic polyurethane foam and pressed against the receiving region in such a manner that the insulation element is sealed off in relation to the receiving region in a fluid-tight manner.

Claims

1.-10. (canceled)

11. A household appliance, comprising: a receiving region; and an insulation element attached to the receiving region for acoustic and/or thermal insulation of the receiving region, said insulation element being manufactured from a viscoelastic polyurethane foam and pressed against the receiving region in such a manner that the insulation element is sealed off in relation to the receiving region in a fluid-tight manner.

12. The household appliance of claim 11, constructed in a form of a water-guiding household appliance.

13. The household appliance of claim 11, wherein at 40° C. and at a frequency of 100 to 800 Hz, the polyurethane foam has a loss factor of more than 0.2.

14. The household appliance of claim 11, wherein at 40° C. and at a frequency of 100 to 800 Hz, the polyurethane foam has a loss factor of more than 0.35.

15. The household appliance of claim 11, wherein at 40° C. and at a frequency of 100 to 800 Hz, the polyurethane foam has a loss factor of more than 0.5.

16. The household appliance of claim 11, wherein the polyurethane foam has a thermal conductivity between 20 and 80 mW (m*K).

17. The household appliance of claim 11, wherein the polyurethane foam has a thermal conductivity between 40 and 60 mW (m*K).

18. The household appliance of claim 11, wherein the polyurethane foam has a thermal conductivity between 50 and 60 mW (m*K).

19. The household appliance of claim 11, wherein the polyurethane foam has a density of less than 300 kg/m.sup.3.

20. The household appliance of claim 11, wherein the polyurethane foam has a density of less than 250 kg/m.sup.3.

21. The household appliance of claim 11, wherein the polyurethane foam has a density of less than 200 kg/m.sup.3.

22. The household appliance of claim 11, wherein the insulation element includes an elastically deformable sealing lip, which is pressed against the receiving region, in order to seal off the insulation element in relation to the receiving region in a fluid-tight manner.

23. The household appliance of claim 11, wherein the polyurethane foam is hydrophilic.

24. The household appliance of claim 11, wherein the polyurethane foam absorbs water during a program sequence of the household appliance and releases the water toward an end of the program sequence.

25. The household appliance of claim 11, further comprising particles embedded into the polyurethane foam.

26. The household appliance of claim 11, further comprising structural parts arranged in the insulation element.

27. The household appliance of claim 26, wherein the polyurethane foam damps vibrations generated by the structural parts.

Description

[0030] Further advantageous embodiments and aspects of the household appliance form the subject matter of the subclaims and of the exemplary embodiments of the household appliance that are described below. The household appliance is described in greater detail below using preferred embodiments with reference to the accompanying figures, in which:

[0031] FIG. 1 shows a schematic perspective view of an embodiment of a household appliance;

[0032] FIG. 2 shows a significantly enlarged schematic sectional view of an embodiment of a receiving region for the household appliance in accordance with FIG. 1;

[0033] FIG. 3 shows a significantly enlarged schematic sectional view of a further embodiment of a receiving region for the household appliance in accordance with FIG. 1;

[0034] FIG. 4 shows a further significantly enlarged schematic sectional view of the receiving region in accordance with FIG. 2;

[0035] FIG. 5 shows a significantly enlarged schematic sectional view of a further embodiment of a receiving region for the household appliance in accordance with FIG. 1;

[0036] FIG. 6 shows a further significantly enlarged schematic sectional view of the receiving region in accordance with FIG. 5;

[0037] FIG. 7 shows a schematic sectional view of an embodiment of a mold for producing an insulation element for the receiving region in accordance with FIG. 2;

[0038] FIG. 8 shows a further schematic sectional view of the mold in accordance with FIG. 7;

[0039] FIG. 9 shows a further schematic sectional view of the mold in accordance with FIG. 7;

[0040] FIG. 10 shows a further schematic sectional view of the mold in accordance with FIG. 7;

[0041] FIG. 11 shows a schematic sectional view of a further embodiment of a receiving region for the household appliance in accordance with FIG. 1;

[0042] FIG. 12 shows a further schematic sectional view of the receiving region in accordance with

[0043] FIG. 11;

[0044] FIG. 13 shows a schematic sectional view of a further embodiment of a receiving region for the household appliance in accordance with FIG. 1;

[0045] FIG. 14 shows a further schematic sectional view of the receiving region in accordance with FIG. 13; and

[0046] FIG. 15 shows a further schematic sectional view of the receiving region in accordance with FIG. 13.

[0047] In the figures, elements that are identical or have the same function are provided with the same reference characters unless specified otherwise.

[0048] FIG. 1 shows a schematic perspective view of an embodiment of a household appliance 1. In particular, the household appliance 1 is a water-guiding household appliance, such as a household dishwasher or a household washing machine, for example. The household appliance 1 may also, however, be a refrigerator, a cooker, an oven or the like. Subsequently it will be assumed, however, that the household appliance 1 is a household dishwasher.

[0049] The household appliance 1 has a receiving region 2, which can be closed off via a door 3, in particular in a water-tight manner. A sealing facility may be provided for this purpose between the door 3 and the receiving region 2. The receiving region 2 is preferably cuboid in shape. The receiving region 2 may be a dishwasher cavity. The receiving region 2 may be arranged in a housing of the household appliance 1. The receiving region 2 and the door 3 may form a dishwasher interior 4 for washing items to be washed.

[0050] The door 3 is shown in its opened position in FIG. 1. The door 3 can be closed or opened by pivoting about a pivot axis 5 provided at a lower end of the door 3. A loading opening 6 of the receiving region 2 can be closed or opened with the aid of the door 3. The receiving region 2 has a base 7, a ceiling 8 arranged opposite the base 7, a rear wall 9 arranged opposite the closed door 3, and two side walls 10, 11 arranged opposite one another. The base 7, the ceiling 8, the rear wall 9 and the side walls 10, 11 can be manufactured from a stainless-steel sheet, for example. Alternatively, the base 7 may be manufactured from a plastic material, for example.

[0051] Furthermore, the household appliance 1 has at least one receptacle for items to be washed 12 to 14. A number of, for example three, receptacles for items to be washed 12 to 14 can preferably be provided, wherein the receptacle for items to be washed 12 can be a lower receptacle for items to be washed or a bottom basket, the receptacle for items to be washed 13 can be an upper receptacle for items to be washed or an upper basket, and the receptacle for items to be washed 14 can be a cutlery drawer. As additionally shown in FIG. 1, the receptacles for items to be washed 12 to 14 are arranged one above the other in the receiving region 2. Each receptacle for items to be washed 12 to 14 is optionally able to be shifted into or out of the receiving region 2. In particular, each receptacle for items to be washed 12 to 14 can be inserted or moved into the receiving region 2 in an insertion direction E (arrow) and extracted or moved out from the receiving region 2 against the insertion direction E (arrow) in an extraction direction A (arrow).

[0052] FIG. 2 shows a significantly enlarged schematic sectional view of an embodiment of the receiving region 2. In particular, only a cut-out of the side wall 11 is shown in FIG. 2. As already mentioned, the side wall 11 may be manufactured from a stainless steel sheet, for example. The side wall 11 comprises an inner side 15 facing toward the dishwasher interior 4 as well as an outer side 16 facing away from the dishwasher interior 4. The inner side 15 and the outer side 16 are placed in parallel with one another. The side wall 11 has a thickness d11. The thickness d11 may amount to 0.2 to 1 mm, for example.

[0053] The household appliance 1 comprises an insulation element 17 attached to the receiving region 2 for the acoustic damping or insulation of the receiving region 2. The insulation element 17 may also be referred to as damping element. The insulation element 17 also has thermal damping properties or thermal insulation properties. The insulation element 17 may envelop the receiving region 2. This means that the insulation element 17 may be provided on the base 7, on the ceiling 8, on the side walls 10, 11 and/or on the door 3. Alternatively, the insulation element 17 may also, for example, only be provided on the side walls 10, 11 or only on the side walls 10, 11 and on the rear wall 9. A plurality of insulation elements 17 may be provided. For example, each side wall 10, 11 can be assigned an insulation element 17 of this kind in each case.

[0054] The insulation element 17 is provided on the outside of the receiving region 2, facing away from the dishwasher interior 4. In particular, the insulation element 17 is attached to the outer side 16 of the side wall 11, as shown in FIG. 2. The insulation element 17 may be fused or adhesively bonded to the outer side 16, for example. The insulation element 17 may also only be applied to the outer side 16, or pressed against it. The insulation element 17 has a thickness d17 of preferably more than 2 mm, further preferably of more than 10 mm, further preferably of more than 15 mm. The thickness d17 is therefore preferably a multiple greater than the thickness d11.

[0055] The insulation element 17 comprises a foamed matrix material 18, in which particles 19 are embedded. In the present case, “foamed” means that a large number of cells or pores 20 are enclosed in the matrix material 18. The pores 20 may be filled with air, for example. The pores 20 may have any given geometry. For example, the pores 20 are in the shape of a sphere or ellipsoid. Together, the matrix material 18 and the pores 20 form a polyurethane foam 21 (PUR foam). A polyurethane can be produced by a mixture of multiple raw components, namely an isocyanate and a polyol. Furthermore, the mixture may also contain a propellant. The isocyanate and the polyol are each liquids. If the propellant is present in the mixture of the isocyanate and the polyol, which leads to outgas sing when the isocyanate reacts with the polyol, the matrix material 18 is foamed up as part of the chemical reaction, whereby the pores 20 occur in the matrix material 18 and the polyurethane foam 21 is formed. The insulation element 17 comprises a surface 22, which is facing toward the outer side 16, and a surface 23, which is facing away from the outer side 16.

[0056] The pores 20 are preferably closed. This means that the pores 20 are not connected to one another. The pores 20, however, may also be open or open-pored. In this case, the pores 20 are connected to one another. The matrix material 18 and thus the polyurethane foam 21 may be equipped with the widest range of material properties. The material properties substantially depend upon the chemical constituents of the raw components. The polyurethane foam 21 preferably has viscoelastic properties. In the present case, “viscoelasticity” refers to a partially elastic and partially viscous material behavior. Viscoelastic materials therefore combine the features of solids and liquids.

[0057] The polyurethane foam 21 has a thermal conductivity between 20 and 80 mW (m*K), preferably between 40 and 60 mW (m*K), further preferably between 50 and 60 mW (m*K). The polyurethane foam 21 may have a density of less than 300 kg/m.sup.3, preferably of less than 250 kg/m.sup.3, further preferably of less than 200 kg/m.sup.3.

[0058] The insulation element 17 is preferably directly foamed onto the receiving region 2, in particular onto the side wall 11. To this end, chemical additives that prevent the insulation element 17 from detaching from the receiving region 2 may be mixed into the matrix material 18. Furthermore, the outer side 16 of the side wall 11 may alternatively or additionally be pretreated, for example roughened, so that the connection between the insulation element 17 and the side wall 11 is not able to detach. Alternatively, the insulation element 17 may also be adhesively bonded to the receiving region 2, fused onto it or even only placed on it or pressed against it.

[0059] Due to the insulation element 17 being attached to the receiving region 2 over its entire area, an effective acoustic insulation of the receiving region 2 is ensured. One advantage of completely foaming around the receiving region 2 with the insulation element 17 is that any cracks present are closed off without gaps, whereby once again an improved acoustic insulation is ensured.

[0060] The particles 19 are arranged evenly distributed in the matrix material 18. Furthermore, the particles 19 may act as nucleus points for the pores 20. The particles 19 are preferably mixed into the raw components of the matrix material 18 to be mixed. Metals, rocks or other kinds of inorganic materials are eligible as particles 19. Organic materials, such as plastics for example, are also eligible if the density and the modulus of elasticity of the particles 19 are greater than those of the matrix material 18.

[0061] Particularly preferably, the particles 19 are graphite particles, in particular expanded graphite particles. The use of expanded graphite particles has the advantage that the particles 19 have intumescent properties in this case. In the present case, “intumescence” is to be understood as meaning an expansion or swelling, i.e. an increase in volume, of the particles 19 without a chemical transformation of the same, when acted upon by heat. This means that, when heat acts upon the insulation element 17, the matrix material 18 is able to disintegrate, while the particles 19 embodied as expanded graphite particles expand or swell up and thus form a carbon foam acting as a heat retardant at or on the receiving region 2.

[0062] As already mentioned, the particles 19 have a greater density than the polyurethane foam 21 and than the matrix material 18. The particles 19 may have a density between 500 and 8,000 kg/m.sup.3, in particular of 2,200 kg/m.sup.3. As already mentioned, the modulus of elasticity of the particles 19 is also greater than the modulus of elasticity of the matrix material 18. The particles 19 preferably have a particle size of less than 500 μm. The particles 19 are present as a powder and, due to their size, are small enough to be evenly distributed in the matrix material 18. The size of the particles 19 is substantially smaller than 500 μm. This means that particles 19 that are larger than 500 μm are also permissible, but it is advantageous if 60% of the particles 19 are smaller than 500 μm. Preferably 80%, in particular 90%, of the particles 19 are smaller than 500 μm. By mixing the particles 19 into the matrix material 18, the pore structure of the polyurethane foam 21 is changed. This means the size, the number and/or the geometry of the pores 20 in the insulation element 17.

[0063] To produce the insulation element 17, the particles 19 of one or more of the liquid raw components of the matrix material 18 are added and evenly distributed in the mixture of the raw components. It is also possible to add the particles 19 to the already-mixed raw components, while they are still liquid. Furthermore, different kinds of particles 19 of different substances can be combined. These particles 19 may also have differences in their size distribution and physical properties. If particles 19 of the same or different size, kind and amount are added, a wide range of differently optimized insulation elements 17 can be produced with the very same raw components. This can be used to produce insulation elements 17 for different application purposes at one production plant.

[0064] At 40° C. and at a frequency of 100 to 800 Hz, the insulation element 17 has a loss factor of more than 0.2, preferably of more than 0.35, further preferably of more than 0.5. In the present case, the “loss factor” is to be understood as meaning, in the case of physical vibrations that have different natures, the ratio of the imaginary part subject to loss to the loss-free real part of a complex variable. By adding the particles 19 to the matrix material 18, the loss factor of the insulation element 17 can be influenced. Advantageously, this relationship can be used if, as a result, an increase in the loss factor takes place over the entire frequency and temperature range or also if an increase is possible in the frequency and temperature range relevant to this individual case.

[0065] FIGS. 3 and 4 each show a schematic partial sectional view of a further embodiment of a receiving region 2. In particular, FIGS. 3 and 4 each show only the side wall 11 of the receiving region 2. As already mentioned, the insulation element 17 comprises the surface 22, which is assigned to the outer side 16 of the side wall 11 and rests against it, as well as the surface 23 facing away from the surface 22. An elastically deformable sealing lip 24 is provided on the surface 22. The sealing lip 24 is formed from the polyurethane foam 21. As shown in FIG. 4, the insulation element 27 is pressed against the side wall 11, in particular against the outer side 16, in such a manner that the sealing lip 24 is elastically deformed. The sealing lip 24 is therefore pressed in or compressed. This means that the insulation element 17 is sealed off in relation to the receiving region 2, in particular in relation to the side wall 11, in a fluid-tight manner. Even if the polyurethane foam 21 contracts, the sealing lip 24 provides enough material that the sealing lip 24 seals off in relation to the receiving region 2 in a fluid-tight manner.

[0066] FIGS. 5 and 6 each show a schematic partial sectional view of a further embodiment of a receiving region 2. Here too, only the side wall 11 is shown in FIGS. 5 and 6. In this embodiment of the receiving region 2, as opposed to the embodiment of the receiving region 2 in accordance with FIGS. 3 and 4, no sealing lip 24 is provided on the insulation element 17. Instead, the insulation element 17 lies with its surface 22 flat against the outer side 16 of the side wall 11 and seals off in relation to said side wall 11 in a fluid-tight manner.

[0067] With the aid of the insulation element 17, the thermal insulation of the receiving region 2 can be improved and/or the sound emission can be reduced. In this context, the insulation element 17, as already mentioned, is formed such that the function of sealing off in relation to water, in particular in relation to water vapor, is integrated into said insulation element 17. In accordance with FIGS. 5 and 6, for example, this may occur with a positive fit over the entire area, or supported by the sealing lip 24 shown in FIGS. 3 and 4. This means that the surface pressure is increased in the region of the sealing lip 24, and if a contracting of the polyurethane foam 21 possibly occurs over the service life of the household appliance 1, a material reserve can be kept available.

[0068] The polyurethane foam 21 preferably has hydrophilic properties. This can advantageously be used in order to slow down the transport of water vapor, for example during a rinse cycle. After the end of the rinse cycle, the polyurethane foam 21 can release the moisture absorbed from the water vapor back into the surrounding area in a controlled manner, without there being complications in the household appliance 1. In the event that the polyurethane foam 21 has hydrophilic properties, it is in particular open-pored. As a result, the polyurethane foam 21 is able to absorb a particularly large amount of moisture or water vapor.

[0069] FIGS. 7 to 12 show, in a step-by-step manner, the production of a further embodiment of an insulation element 17 and the assembly of the same on the receiving region 2. In this context, the polyurethane foam 21 is used to affix structural parts 25, 26 and enclose them at least partially in itself. The structural parts 25, 26 may be active structural parts or passive structural parts. One example of an active structural part is a fan. One example of a passive structural part may be a cable. In particular, the structural parts 25, 26 may comprise water-guiding structural parts, air-guiding structural parts, water reservoirs, plastic parts for introducing force into the receiving region 2, a fan, a motor, a spring, a cord, electrical lines or components, a non-woven material, a mat, a plastic structural part, foam structural parts, bitumen or the like.

[0070] In order to produce the insulation element 17, first a reinforcement element 27, for example a bitumen mat, and the structural parts 25, 26 are inserted into a mold 28, in particular a pouring mold or casting mold, which has a mold lower part 29 and a mold upper part 30 (FIG. 7). After inserting the reinforcement element 27 as well as the structural parts 25, 26 into a cavity 31 of the mold 28, a mixture 32 of the raw components of the polyurethane foam 21 is introduced into the mold 28 (FIG. 8). The mixture 32 is then able to chemically react under atmospheric pressure or under a vacuum, and in doing so foam up and fill up the cavity 31 entirely with the polyurethane foam 21 (FIG. 9). In this context, the polyurethane foam 21 surrounds the structural parts 25, 26 either fully or, as in the case of structural part 26, at least in sections. The structural part 25, during the foaming of the same with the mixture 32 in the cavity 31, may for example be held in position with the aid of rods or wires. The structural part 26 may be placed on the reinforcement element 27 or on the mold lower part 29 for positioning purposes.

[0071] After the polyurethane foam 21 has fully set and/or cured, the mold 28, as shown in FIG. 10, is opened and the insulation element 17 is demolded. Subsequently, the insulation element 17, as shown in FIGS. 11 and 12, is attached to the outside of the receiving region 2. To this end, for example, the insulation element 17 is pressed against the receiving region 2 in such a manner that a fluid-tight connection is produced between the insulation element and the receiving region 2.

[0072] In order to be able to affix the structural parts 25, 26, the properties of the polyurethane foam 21 as an adhesive may be used to hold the structural parts 25, 26 in place, without carrying out additional measures. If the structural parts 25, 26 involve active components, such as fans for example, then these are simultaneously also vibration-damped through the use of the viscoelastic polyurethane foam 21. As a result, it is further possible for other connection elements, such as screws, clips or the like, to be replaced. Above all, large-area structural parts are particularly suitable for this purpose. Due to the large area, a high holding force of the adhesive connection is produced for the basic design of the receiving region 2. If the polyurethane foam 21 has a large volume and is used as a connecting element between different components in the household appliance 1, then this may offer advantages for the case of transport. Particularly at cold temperatures, the rigidity of the polyurethane foam 21 increases and offers effective properties with regard to shock absorption.

[0073] FIGS. 13 to 15 show an alternative approach for producing the insulation element 17. To this end, the optional reinforcement element 27 as well as the structural parts 25, 26 are attached to the receiving region 2, in particular to the side wall 11, with the aid of a mold 33, which can be fastened directly to the receiving region 2. The mold 33 has a cavity 34 which, after the mold 33 has been attached to the receiving region 2, is filled with the previously mentioned mixture 32 of the raw components of the polyurethane foam 21 (FIG. 14). Subsequently, the polyurethane foam 21 sets and/or cures, and the mold 33, as shown in FIG. 15, can be removed from the receiving region 2 once more and can be used again.

[0074] By integrating the function of the sealing in relation to steam with the aid of the sealing lip 24, it is possible to achieve a saving of further structural parts with the aid of the use of the insulation element 17. By advantageously using the hydrophilic properties of the polyurethane foam 21, it is possible to ensure a targeted absorption of water vapor and subsequent releasing of air moisture to the surrounding area. By integrating the structural parts 25, 26 into the insulation element 17, it is possible to dispense with an additional affixing of the structural parts 25, 26. These are also mounted in the polyurethane foam 21 in a damping manner.

[0075] Although the present invention has been described with reference to exemplary embodiments, it can be modified in numerous different ways.

REFERENCE CHARACTERS USED

[0076] 1 Household appliance [0077] 2 Receiving region [0078] 3 Door [0079] 4 Dishwasher interior [0080] 5 Pivot axis [0081] 6 Loading opening [0082] 7 Base [0083] 8 Ceiling [0084] 9 Rear wall [0085] 10 Side wall [0086] 11 Side wall [0087] 12 Receptacle for items to be washed [0088] 13 Receptacle for items to be washed [0089] 14 Receptacle for items to be washed [0090] 15 Inner side [0091] 16 Outer side [0092] 17 Insulation element [0093] 18 Matrix material [0094] 19 Particle [0095] 20 Pore [0096] 21 Polyurethane foam [0097] 22 Surface [0098] 23 Surface [0099] 24 Sealing lip [0100] 25 Structural part [0101] 26 Structural parts [0102] 27 Reinforcement element [0103] 28 Mold [0104] 29 Mold lower part [0105] 30 Mold upper part [0106] 31 Cavity [0107] 32 Mixture [0108] 33 Mold [0109] 34 Cavity [0110] A Extraction direction (arrow) [0111] d11 Thickness [0112] d17 Thickness [0113] E Insertion direction (arrow)