EP3382284B1 - Domestic appliance and method for manufacturing same - Google Patents

Description

The invention relates to a hob according to the preamble of claim 1.

From the prior art, for example EP 2 427 032 A2 , a hob with a reflective shielding plate made of aluminum, with a hob plate and with an opaque coating applied to an underside of the hob plate is known. If the coating has defects, the shielding plate and the hob plate act together as a light guide and/or cause light artifacts which are visible through the hob plate. Post-processing of the hob plate may be necessary to prevent these light artifacts from occurring.

Furthermore, the FR 2 827 114 A1 a cooktop having a light guide disposed along an outer periphery of a heating element of the cooktop to visually indicate at least one heating zone of the cooktop.

In addition, from the WO 2012/085821 A1 a coating of a glass unit, in particular a hob plate, of a hob device is known, which is arranged directly on the glass unit at least in a partial area of a rear side.

Furthermore, the U.S. 8,168,925 B2 also a glass ceramic plate designed as a hob plate, which is intended to cover or accommodate at least one heating element, the glass ceramic plate having a coating with at least two contrasting zones for marking heating zones.

A hob according to the JP 2013 092361 A has a specially designed hob plate which allows an electromagnetic field generated by at least one heating element to pass through largely unhindered in order to enable particularly efficient heating of the cooking utensil that has been set up.

In addition, from the pamphlet WO 01/41510 A1 a hob with light sources for displaying a heating area of heating elements is known. The teaching of this publication focuses on using as few light sources as necessary to identify the heating area, namely an edge of the heating elements, for a user.

The object of the invention is therefore in particular to provide a generic device with improved properties in terms of efficiency. the The object is achieved by the characterizing features of patent claim 1, while advantageous refinements and developments of the invention can be found in the dependent claims.

The invention is based on a hob with at least one household appliance device with a heating unit, which has at least one heating element designed as an inductor, with at least one electronic system and with at least one shielding plate, in particular an aluminum plate, for electromagnetic shielding of at least one electronic system, the shielding plate being it is intended to carry at least the heating element directly or indirectly.

It is proposed that at least one section of the shielding plate is provided to substantially suppress at least one directed reflection of light, in particular visible light. This configuration can in particular increase efficiency, advantageously light absorption efficiency, manufacturing efficiency and/or component efficiency. Furthermore, a proportion of defective production can advantageously be reduced. In addition, light-shielding elements for light-shielding a control panel can advantageously be dispensed with. Furthermore, user comfort can be increased.

In this context, a “household appliance device” should be understood to mean in particular at least one part, in particular a subassembly, of a household appliance. The household appliance can be designed, for example, as a refrigerating appliance, in particular as a refrigerator and/or as a freezer, or also as a cleaning appliance. However, the household appliance is advantageously designed as a cooking appliance, in particular as an oven, as a microwave, as a grill and/or preferably as a hob. The household appliance device can have a plurality of shielding plates. However, the domestic appliance device advantageously has exactly one shielding plate. Furthermore, the domestic appliance device has a heating unit with at least one heating element, in particular a radiant heating element, a resistance heating element and/or preferably an induction heating element, which is designed as an inductor. In addition, the domestic appliance device includes the electronics, which are provided in particular at least for controlling the heating unit. “Provided” is to be understood in particular as being specially designed and/or equipped. The fact that an object is provided for a specific function is to be understood in particular to mean that the object fulfills and/or executes this specific function in at least one application and/or operating state.

A "shielding plate" is to be understood in particular as a flat and advantageously one-piece element which is intended to weaken an electrical, electromagnetic and/or magnetic field in at least one area, in particular to protect electronics. Furthermore, the shielding plate is intended to carry at least one heating element, in particular an inductor, directly or indirectly. The shielding plate includes a base plate and can in particular additionally have a coating. The entire shielding plate consists at least partially, preferably at least to a large extent and particularly preferably completely, of a metal, in particular aluminum. A "flat" object is to be understood in particular as an object in which a largest side surface of a smallest, in particular imaginary cuboid, which just completely encloses the object, by at least 50%, advantageously by at least 100%, preferably by at least 200% and more preferably at least 500% larger than each side face of the parallelepiped perpendicular to the largest side face. Furthermore, “in one piece” is to be understood as being at least cohesively connected and/or formed with one another. The material connection can be produced, for example, by an adhesive process, an injection molding process, a welding process, a soldering process and/or another process. Advantageously, one-piece from one piece and/or formed in one piece should be understood. This one piece is preferably made from a single blank, a mass and/or a cast, for example in an extrusion process, in particular a single-component and/or multi-component extrusion process, and/or an injection molding process, in particular a single-component and/or multi-component injection molding process. The expression "at least a large part" is to be understood in particular as at least 55%, advantageously at least 65%, preferably at least 75%, particularly preferably at least 85% and particularly advantageously at least 95%.

A "directed reflection" is to be understood in particular as a reflection of light in which an incident light beam and a reflected light beam run in a common plane perpendicular to a main plane of extension of the shielding plate. The reflection is advantageously formed at least as a light reflection of, in particular, visible light, advantageously with a wavelength between 380 nm and 780 nm. Furthermore, the expression “substantially suppress directed reflection of light” is to be understood in particular as meaning that the section is at least 50% advantageous at least 70%, particularly advantageously at least 85%, preferably at least 95%, preferably at least 98.5% and particularly preferably at least 99.7% of the light is absorbed and/or diffusely reflected.

In particular, in order to provide light absorption efficiency and/or user comfort, it is also proposed that the section has a reflection coefficient of at most 50%, in particular at most 30%, advantageously at most 15%, particularly advantageously at most 5%, preferably at most 1.5 %, and more preferably at most 0.3%.

In a further embodiment of the invention, it is proposed that the section has a coating, in particular different from an atmospheric oxidation layer, which at least partially causes the suppression of the directed reflection. As a result, a light absorption efficiency can advantageously be increased. The coating advantageously has a thickness of at least 100 nm, in particular at least 300 nm, advantageously at least 800 nm, particularly advantageously at least 2 μm and particularly preferably at least 5 μm, and at most 1 mm, in particular at most 300 μm of at most 100 μm, particularly advantageously of at most 50 μm and particularly preferably of at most 25 μm.

In addition, it is proposed that the coating be in the form of an aluminum oxide layer and/or an aluminum hydroxide layer. Thereby, a light absorption efficiency can be further increased. Furthermore, manufacturing efficiency can be increased. In particular, the base plate is designed as an aluminum plate. In particular, the coating consists at least partially, preferably at least to a large extent and particularly preferably entirely of Al ₂ O ₃ and/or Al(OH) ₃ .

In addition, it is proposed that the section has a surface with an average roughness of at least 1 μm, in particular at least 5 μm, advantageously at least 20 μm, particularly advantageously at least 60 μm, preferably at least 150 μm and particularly preferably at least 300 μm , Has, which at least partially causes the suppression of the specular reflection. In this way, particularly strong light reflections can be avoided since, in particular, diffuse light scattering can be made possible. In particular, the surface is designed as a ground, as a sandblasted and/or as an etched surface. Furthermore, a reflection on the surface is advantageously designed as a diffuse reflection. Under An "average roughness" is to be understood in particular as an average distance between a measuring point located on the surface and a center line, with the center line intersecting a profile of the surface within a reference section in such a way that the sum of deviations of the profile in relation to the center line is minimal.

It is also proposed that the domestic appliance device has at least one hob plate which is arranged at least essentially parallel to the shielding plate. In particular, a main plane of extent of the hob plate is arranged at least essentially parallel to a main plane of extent of the shielding plate. The hob plate is advantageously arranged on a side of the section of the shielding plate on which it is possible to suppress the reflection of light. The hob plate particularly advantageously has a control panel which is provided in at least one operating state for the domestic appliance to be operated by a user. A surrounding area of the control panel is preferably free of a light-shielding element, which is at least intended to provide a light-shielding of the control panel. “At least essentially parallel” is to be understood in particular as an orientation of a plane relative to a reference plane, with the plane deviating from the reference plane in particular by less than 8°, advantageously less than 4° and particularly advantageously less than 2°. Furthermore, a "main extension plane" of an object is to be understood in particular as a plane which is parallel to a largest side surface of a smallest, in particular imaginary cuboid, which just completely encloses the object, and which in particular is defined by a center point, in particular a geometric center point, of the cuboid runs. As a result, a storage area for cookware can advantageously be provided.

According to a further embodiment of the invention, it is proposed that the domestic appliance device has at least one, in particular artificial, light source which, viewed in particular in a direction which lies in a main extension plane of the shielding plate, is arranged between the hob plate and the shielding plate. As a result, user comfort can be further increased since, in particular, partial areas of the hob plate can be illuminated. Furthermore, the light source is covered by the hob plate, in particular when viewed in a direction perpendicular to the main extension plane of the shielding plate. The light source can in particular be connected to the hob plate. However, the light source with the shielding plate is advantageous tied together. The light source is advantageously in the form of an incandescent lamp, a halogen incandescent lamp, a gas discharge lamp and/or preferably a light-emitting diode or LED.

In order to further increase user comfort and/or to increase design flexibility and/or diversity, it is also proposed that the domestic appliance device has an at least essentially opaque coating which at least partially covers the hob plate on a side facing the shielding plate. The coating is intended to prevent a view through the hob plate, which is designed in particular to be transparent, into an interior area of the household appliance designed as a hob. Furthermore, the coating is intended to prevent light reflections from being visible on the shielding plate, at least in a partial section of the hob plate. An “at least essentially opaque coating” is to be understood in particular as an opaque coating which, within the scope of customary production methods, can have defects which at least partially allow light to be transmitted.

To produce the shielding plate, at least one section of a raw plate is preferably treated in at least one method step to suppress at least one directed reflection. This configuration can in particular increase efficiency, advantageously light absorption efficiency, manufacturing efficiency and/or component efficiency. Furthermore, a proportion of defective production can advantageously be reduced. In addition, light-shielding elements for light-shielding a control panel can advantageously be dispensed with. Furthermore, user comfort can be increased. The section of the raw board can be roughened in the method step, for example by means of emery, by means of sandblasting, by means of bristle blasting and/or by means of etching. Furthermore, the section of the raw plate can be coated in the method step and/or in a further method step, for example by means of anodizing, by means of electrophoresis and/or with an anti-reflection coating.

Further advantages result from the following description of the drawing. Two exemplary embodiments of the invention are shown in the drawings. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into further meaningful combinations.

Fig. 1

eine Draufsicht auf ein beispielhaft als Kochfeld ausgebildetes Haushaltsgerät mit einer Haushaltsgerätevorrichtung,

Fig. 2

eine Schnittdarstellung durch einen Teil der Haushaltsgerätevorrichtung mit einer teilweise aufgerauten Abschirmplatte, mit einer Kochfeldplatte und mit einer Lichtquelle und

Fig. 3

eine Schnittdarstellung durch einen Teil einer weiteren Haushaltsgerätevorrichtung mit einer teilweise beschichteten Abschirmplatte, mit einer Kochfeldplatte und mit einer Lichtquelle.

Show it:

1

a top view of a household appliance designed as a hob, for example, with a household appliance device,

2

a sectional view through part of the household appliance device with a partially roughened shielding plate, with a hob plate and with a light source and

3

a sectional view through part of another household appliance device with a partially coated shielding plate, with a hob plate and with a light source.

figure 1 shows a domestic appliance 10a designed as a cooking appliance in a schematic representation. In the present case, the household appliance 10a is designed as a hob.

The household appliance 10a has a household appliance device. In the present case, the domestic appliance device is designed as a hob device. The home appliance device includes a heating unit (not shown). The heating unit is intended to heat a cooking utensil (not shown). For this purpose, the heating unit has at least one heating element (not shown). In the present case, the heating element is designed as an inductor. In addition, the domestic appliance device has electronics (not shown).

Furthermore, the household appliance device includes a shielding plate 20a (cf. figure 2 ). The shielding plate 20a is flat. Furthermore, the shielding plate 20a is formed in one piece. In the present case, the shielding plate 20a is designed as an aluminum plate. The shielding plate 20a is designed as a base plate 24a. The shielding plate 20a is arranged between the heating unit and the electronics. In the present case, the shielding plate 20a is arranged above the electronics, viewed in the direction of gravity. Further, the shielding plate 20a is disposed under the heating unit as viewed in the direction of gravity. Furthermore, a main extension plane of the shielding plate 20a is arranged perpendicular to the direction of gravity in an installation position. Alternatively, a shielding plate could be composed of several components. In addition, a shielding plate could consist of a material other than aluminum, in particular an alloy, advantageously an aluminum alloy, a copper alloy, an iron alloy and/or a mu-metal, and/or a metal, advantageously copper and/or iron.

The shielding plate 20a is provided for electromagnetic shielding of the electronics. In the present case, the shielding plate 20a shields the electronics from an electromagnetic field generated by the heating element. In addition, the shielding plate 20a is provided to support the heating unit.

The domestic appliance device also includes a hob plate 12a. The hob plate 12a is formed in one piece. In the present case, the hob plate 12a is designed as a glass ceramic plate. The hob plate 12a is arranged at least essentially parallel to the shielding plate 20a. In the present case, the hob plate 12a is arranged above the shielding plate 20a in the direction of gravity. The hob plate 12a is provided for placing the cooking utensil. The hob plate 12a has a control panel 16a. In at least one operating state, the control panel 16a is provided for a user to operate the household appliance 10a. A surrounding area of the control panel 16a is free of a light-shielding member, which is provided at least for light-shielding of the control panel 16a.

The domestic appliance device also has a light source 18a. In the present case, the light source 18a is in the form of a light-emitting diode (LED). In figure 2 it can be seen that the light source 18a is arranged between the hob plate 12a and the shielding plate 20a. The light source 18a is fixed to the shielding plate 20a. The light source 18a is provided in at least one operating state, in particular a heating operating state, to illuminate a section of the hob plate 12a. Alternatively, a domestic appliance device could have a plurality of light sources.

In particular, in order to limit the illumination of the hob plate 12a by the light source 18a, the domestic appliance device has an at least essentially opaque coating 14a. The coating 14a covers the hob plate 12a at least partially on a side facing the shielding plate 20a. The coating 14a covers a further section of the hob plate 12a that is designed differently from the section of the hob plate 12a. The coating 14a is intended to prevent a view through the hob plate 12a into an interior area of the household appliance 10a designed as a hob. Furthermore, the coating 14a is provided to prevent the visibility, in particular of multiple light reflections, between the hob plate 12a and the shielding plate 20a. However, the coating 14a can have defects, in particular holes, as part of the usual manufacturing processes.

A section 22a of the shielding plate 20a is intended to substantially suppress at least specular reflection of light. For this purpose, the section 22a has a roughened surface. The section 22a has a surface with an average roughness of at least 1 μm. The surface at least partially suppresses the directed reflection, so that particularly strong reflections can be avoided. In the present case, the surface allows non-directional and/or diffuse reflection.

figure 2 FIG. 1 also shows an example of a light beam path in an intermediate area between the hob plate 12a and the shielding plate 20a. A first bundle of rays 28a emitted by the light source 18a travels through the intermediate region in a first direction. The hob plate 12a brings about a transition of the first beam 28a into a second beam 30a by means of directed reflection. The second bundle of rays 30a travels through the intermediate region in a second direction. The second direction encloses the same angle with the hob plate 12a as the first direction with the hob plate 12a. The roughened surface of the section 22a brings about a transition of the second bundle of rays 30a into a multiplicity of third bundles of rays 32a by means of undirected and/or diffuse reflection. The third bundles of rays 32a have different directions from one another. The third bundles of rays 32a thus impinge on different partial sections of the coating 14a. If the coating 14a has a defect, in particular a hole, then the third bundles of rays 32a penetrate the hob plate 12a at different points. As a result, a light that is diffusely reflected on the shielding plate 20a is distributed uniformly over the hob plate 12a. Furthermore, a directed movement of the light emitted by the light source 18a is prevented. In addition, strong reflections on the hob plate 12a and on the shielding plate 20a are avoided.

In the figure 3 another embodiment of the invention is shown. The following descriptions are essentially limited to the differences between the exemplary embodiments, with regard to components, features and functions that remain the same on the description of the exemplary embodiment of FIG Figures 1 and 2 can be referred. To distinguish between the exemplary embodiments, the letter a is in the reference numerals of the exemplary embodiment in FIGS Figures 1 and 2 by the letter b in the reference numerals of the embodiment of FIG figure 3 replaced. With regard to components with the same designation, in particular with regard to components with the same reference numbers, can in principle also on the drawings and / or the description of the embodiment of Figures 1 and 2 to get expelled.

In the present case, a section 22b of a shielding plate 20b has a coating 26b. The coating 26b at least partially suppresses the specular reflection.

The coating 26b is formed as an aluminum oxide layer. The portion 22b has a reflection coefficient of at most 50%. In the present case, section 22b has a reflection coefficient of at most 0.3%. Alternatively, a coating could consist at least partially of aluminum hydroxide.

In the present case, the coating 26b of the section 22b brings about a partial absorption of a second bundle of rays 30b. As a result, a directed movement of the light emitted by the light source 18b is partially prevented. Furthermore, the coating 26b brings about a transition of a non-absorbed part of the second beam 30b into a third beam 32b by means of directed reflection. The third bundle of rays 32b travels through the intermediate region in a third direction. The third direction encloses the same angle with the coating 26b as the second direction with the coating 26b. If the third bundle of rays 32b strikes a defect, in particular a hole, in a coating 14b, the third bundle of rays 32b penetrates a hob plate 12b. The third bundle of rays 32b has a reduced intensity compared to a first bundle of rays 28b emitted by a light source 18b. This avoids strong reflections on the hob plate 12b and on the shielding plate 20b.

Reference sign

10

household appliance

12

hob plate

14

coating

16

control panel

18

light source

20

shielding plate

22

section

24

base plate

26

coating

28

bundle of rays

30

bundle of rays

32

bundle of rays

Claims (8)

1. Hob comprising at least one household appliance device comprising a heating unit having at least one heating element embodied as an inductor, comprising at least one electronics assembly and comprising at least one shield plate (20a-b) for electromagnetic shielding of the electronics assembly, wherein the shield plate (20a-b) is provided to bear at least the heating element directly or indirectly, wherein the shield plate at least partially consists of a metal, characterised in that at least one section (22a-b) of the shield plate (20a-b) is provided to substantially suppress at least one directed reflection of light.
2. Hob according to claim 1, characterised in that the section (22b) has a reflection coefficient of a maximum of 50%.
3. Hob according to claim 1 or 2, characterised in that the section (22b) has a coating (26b) which at least partially causes suppression of the directed reflection.
4. Hob according to claim 3, characterised in that the coating (26b) is embodied as an aluminium oxide layer and/or as an aluminium hydroxide layer.
5. Hob according to one of the preceding claims, characterised in that the section (22a) has a surface with an average roughness of at least 1 µm which at least partially causes the suppression of the directed reflection.
6. Hob according to one of the preceding claims, characterised in that the household appliance device has at least one hob plate (12a-b) which is arranged at least substantially parallel to the shield plate (20a-b).
7. Hob according to claim 6, characterised in that the household appliance device has at least one light source (18a-b) which is arranged between the hob plate (12a-b) and the shield plate (20a-b).
8. Hob according to claim 6 or 7, characterised in that the household appliance device has an at least substantially opaque coating (14a-b) which at least partially covers the hob plate (12a-b) on a side facing the shield plate (20a-b), wherein the coating (14a-b) is provided to avoid visibility of light reflection on the shield plate (20a-b) at least in one subsection of the hob plate (12a-b).

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