DE102011088675A1 - Hob plate use in induction hob, has electrical heating conductor fixed at outer surface of base plate, and positioning surface for positioning dishes, where outer surface is formed opposite to positioning surface - Google Patents

Abstract

The plate has an electrical heating conductor (12a) fixed at an outer surface of a base plate (10a), and a positioning surface (11a) for positioning dishes. The outer surface is formed opposite to the positioning surface, and the conductor is formed as a metallic conductive coating (16a) of the base plate. The coating is applied using a screen printing method or a cathodic sputtering method. A protecting layer is applied on the conductor that heats a heat holding zone (20a) at a temperature of 60-105 degree Celsius, where a portion of the conductor is formed in a loop, helical or star shape.

Description

The invention is based on a hob plate according to the preamble of claim 1.

It is known in hobs to provide a hob plate with a base plate made of a glass ceramic, which is provided for setting up to be heated Gargeschirr.

The object of the invention is in particular to provide a generic hob plate with an extended functionality. The object is achieved by the features of claim 1, while advantageous embodiments and modifications of the invention can be taken from the dependent claims.

The invention is based on a hob plate with at least one base plate with a mounting surface for cooking utensils.

It is proposed that the hob plate comprises an electrical heating conductor, which is fixedly arranged on the base plate. A "base plate" is to be understood, in particular, as an element of the cooktop plate which comprises at least 70%, in particular at least 80%, and preferably at least 90%, of a total mass of the cooktop plate. Preferably, the base plate limits a hob in an operational state upwards. Preferably, the base plate is at least partially and particularly advantageously completely formed from a glass ceramic. A "footprint" is to be understood in particular a surface of the base plate, which is provided in an operational state of the hob for setting up to be heated Garware. By "provided" is intended to be understood in particular specifically designed and / or equipped and / or programmed. A "heating conductor" is to be understood in particular as meaning an electrical conductor which, at an ambient temperature of 20 ° C. and a current flow of at most 20 A and in particular of not more than 16 A through the conductor, has a temperature of at least 50 ° C., in particular of at least 60 ° C and preferably of at least 70 ° C and preferably remains free of damage. An "electrical conductor" should in particular be an electrically conductive element having a specific electrical conductivity of at least 5 × 10 ⁵ (Ωm) ^-1 , in particular of at least 10 ⁶ (Ωm) ^-1 and preferably of at least 2 × 10 ⁶ (Ωm) ^-1 at 20 ° C, which in particular has at least one longitudinal extent which is at least 20 times, in particular at least 100 times and advantageously at least 500 times greater than at least one transverse to the longitudinal extent transverse extent. A "longitudinal extent" is to be understood in particular a maximum extent of the heating conductor in a developed and straight state. Including that the heating element is "fixedly arranged" on the base plate, should be understood in particular that the heating element and the base plate in a mounted state of the hob plate and a disassembled state of a cooktop, preferably inextricably tool-less, are interconnected. In particular, between the heating conductor and the base plate, a further layer, in particular a layer with a high thermal conductivity, be introduced. Preferably, however, the heating conductor and the base plate are connected directly to each other. The heating conductor may be completely or preferably partially embedded in the base plate. Particularly advantageously, the heating conductor is arranged on an outer surface of the base plate. By the fact that the heating conductor is arranged "on an outer surface of the base plate", it should be understood in particular that the heating conductor rests against the outer surface of the base plate at least partially and preferably completely. An "outer surface" is to be understood, in particular, as meaning a surface which is pierced by at least one beam emanating from a center of gravity of the base plate, the beam finally leaving the base plate at a puncture point.

By such a configuration, a hob can be provided with a hob plate, which includes an extended functionality, in particular a holding surface. This can be advantageously saved space in the hob, which costs and material can be saved. Furthermore, overheating of other components of the hob can be avoided because the heating element can deliver its heating power directly to the base plate. By a direct contact with the base plate energy can also be saved and an excellent temperature control of the holding surface can be achieved. Furthermore, a total weight of the hob can be reduced, which in particular transport costs can be reduced. Furthermore, reliability of a function of a holding surface may be advantageously increased over previous embodiments, and thermal stresses may be reduced. In further developments of the invention, complicated and several connected areas of a holding surface can be supplied with only one heat conductor. Furthermore, a simple retrofitting of existing hobs with a holding surface can be made possible.

In a preferred embodiment of the invention, it is proposed that the heating conductor is arranged on an outer surface of the base plate. This can be structurally simple and with low installation costs of the heating conductor on the Base plate can be arranged, which costs can be reduced. Furthermore, an existing hob plate can be retrofitted with a heating element.

Advantageously, the outer surface of the footprint opposite. As a result, the footprint can be advantageously kept smooth and flat. Furthermore, a mechanical and / or chemical stress on the heat conductor, in particular corrosion and / or exposure to a solvent, can be minimized. Furthermore, can be dispensed with an electrical insulation of the heating element.

In a particularly preferred embodiment of the invention, it is proposed that the heating conductor is a conductive coating of the base plate. A "coating" of the base plate is to be understood in particular to mean a unit which is connected to the base plate in a materially bonded manner by atomic and / or molecular forces. A "conductive coating" is to be understood in particular as a coating which conducts electrical current. Advantageously, a specific electrical conductivity of the conductive coating at 20 ° C. is at least 5 × 10 ⁵ (Ωm) ^-1 , in particular at least 10 ⁶ (Ωm) ^-1 and preferably at least 2 × 10 ⁶ (Ωm) ^-1 . By such a configuration can be provided on the base plate in a simple way an advantageously resistant heating conductor.

It is further proposed that the conductive coating is applied by means of a screen printing process. A "screen printing process" is to be understood in particular as a printing process in which a printing ink is printed on a material to be printed through a preferably fine-meshed fabric, in particular at those points of the fabric which are to remain color-free according to a printed image, mesh openings of the fabric through to make a template impermeable. Preferably, the ink is an electrically conductive ceramic paste. As a result, a conductive ceramic coating can be created inexpensively.

In a further embodiment of the invention it is proposed that the conductive coating is applied by means of a sputtering process. A "cathode sputtering process" is to be understood, in particular, as a vacuum-based coating process in which atoms and / or molecules from a solid, in particular a metal and preferably a noble metal, are dissolved out by bombardment with high-energy ions, preferably noble gas ions, into a gas phase and on To be deposited on a material to be coated. Preferably, following the sputtering process, a laser ablation process is performed to cut out the heat conductor. A "laser ablation process" is to be understood in particular as a targeted removal of material from a surface by bombardment with pulsed laser radiation. In this way, a purely metallic coating of the base plate can be provided.

Advantageously, the cooktop panel comprises a protective layer on the heating conductor. A "protective layer" is to be understood in particular as a layer which is intended to protect the heating conductor against mechanical stress, in particular abrasion, and / or chemical stress, in particular corrosion and / or exposure to solvents and / or cleaning agents to provide. In particular, the protective layer has a stronger adhesion to the base plate and / or a greater hardness and / or a greater corrosion resistance than the heating conductor. Preferably, the protective layer is electrically insulating. By "electrically insulating" should in particular be understood with a specific electrical resistance of at least 10 ⁸ Ωm, in particular at least 10 ¹⁰ Ωm and advantageously at least 10 ¹² Ωm at 20 ° C. In particular, the protective layer may be a jacket completely surrounding the heating conductor, in particular a protective lacquer. However, the protective layer is preferably a coating of the base plate, in particular a ceramic coating and / or a glass enamel and / or a protective lacquer, which is preferably arranged at least partially over the heating conductor designed as a conductive coating. By the fact that the protective layer is arranged "at least partially over" the conductive coating, it should be understood in particular that the protective layer has at least one partial area which is arranged on a side of the conductive coating facing away from the base plate. Advantageously, the entire conductive coating on a side facing away from the base plate of the conductive coating is covered by the protective layer, wherein contact surfaces of a power supply are free of the protective layer. Advantageously, the protective layer is at least partially directly on the conductive coating and particularly advantageously surrounds the conductive coating at least partially. By the fact that the protective layer at least partially surrounds the conductive coating, it should be understood in particular that the protective layer is arranged at least partially over and at least partially laterally next to the conductive coating. The fact that "the protective layer is arranged at least partly laterally next to the conductive coating" is to be understood in particular to mean that at least a partial area of the protective layer is arranged directly adjacent to the conductive coating in a direction parallel to the mounting surface of the base plate. Particularly advantageous is the heating element in at least one Cross section limited only by the protective layer and / or the base plate. By such a configuration, an advantageous protection of the heating element can be provided, in particular if the heating element is applied by a cathode sputtering process. In particular, an application of the heat conductor to the footprint of the base plate can be made possible.

It is also proposed that the heating conductor is arranged at least in a partial region at least substantially loop-shaped and / or spirally and / or star-shaped. "Loop-shaped" is to be understood, in particular, as a shape of the heating conductor in which the heating conductor pierces a plane several times, alternating alternately from one side to another side of the plane, and preferably alternately changing a sign of its curvature. By "helical" is intended to be understood in particular essentially in the form of a planar spiral, preferably a double spiral. By "star-shaped" should be understood in particular essentially in the form of an outer contour of a geometric star. In particular, the outer contour can have rounded corners. As a result, an advantageously large area coverage can be achieved. Furthermore, when used in an induction hob by a star-shaped design, a power loss can be minimized by induced eddy currents in the heating element.

Advantageously, the heating conductor is intended to heat a designed as a holding surface portion of the footprint. A "holding surface" is to be understood in particular a partial area of the footprint, which is provided at least for a warm keeping of parked on the portion cooking dishes. As a result, a hob with a small space requirement for a holding surface can be provided.

It is also proposed that the heating conductor is intended to heat the holding surface to a temperature between 60 ° C and 105 ° C. Preferably, the heating conductor is intended to heat the holding surface to a temperature of at least 70 ° C, in particular of at least 80 ° C and particularly advantageously of at least 90 ° C. Preferably, the heating conductor is intended to heat the holding surface to a temperature of at most 100 ° C. In this way, on the one hand, an advantageous keeping warm of food can be achieved. On the other hand, burning or boiling of food to be cooked or emptying a cooking utensil can be avoided. An "empty cooking of a cooking utensil" should in particular be understood as meaning a complete evaporation of a liquid from the cooking utensil.

In a preferred embodiment of the invention it is proposed that the holding surface is arranged in a region of at least one specially designed and different from a heating zone holding zone. A "warming zone" is to be understood, in particular, as a zone which is arranged on the set-up surface and is preferably specially marked and which is provided exclusively for keeping warm purposes. Preferably, a maximum power of the holding zone is at least 30%, in particular at least 50%, preferably at least 70% and particularly advantageously at least 80% smaller than a maximum power of each heating zone taken by itself. The heating zones are preferably associated with induction heaters and / or radiant heaters and / or resistance heaters. By the fact that the heating conductor is arranged at least "in a region of at least one warming zone" should be understood in particular that the heating element is in a vertical projection on the footprint in the area and that the warming zone comprises the area. As a result, a clearly defined warming zone can be provided.

In a further embodiment of the invention, it is proposed that the base plate at least partially surrounds the heating conductor. By the fact that the base plate "at least partially surrounds the heating conductor, it should be understood, in particular, that the base plate is arranged at least partially laterally next to the heating conductor. The fact that "the base plate is arranged at least partially laterally next to the heating conductor" is to be understood in particular to mean that at least one subregion of the base plate is arranged directly adjacent to the heating element in a direction parallel to the mounting surface of the base plate. In this way, an advantageous protection of the heating element can be achieved. Preferably, a material thickness of the base plate in a direction perpendicular to the main extension plane of the base plate in a partial region in which the heating conductor is arranged, lower than in an environment of the portion. As a result, a heat conduction through the base plate can be advantageously increased.

Further advantages can be found in the following drawing descriptions. In the drawings, embodiments of the invention are shown. The drawings, the descriptions 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 meaningful further combinations.

Show it:

1a a hob with a cooking zone comprising a holding zone in a plan view,

1b the hob plate in a not to scale sectional view taken along a line Ib-Ib in 1a .

2a another hob plate with a holding surface and a protective layer in a plan view,

2 B the hob plate in a not to scale sectional view along a line IIb-IIb in 2a .

2c the hob plate off 2a in a perspective partial view from below,

3 another hob plate with a holding surface and a protective layer in a plan view,

4a another hob plate with a holding surface with a embedded in a base plate of the cooktop heating element and

4b the hob plate in a not to scale section along a line IVb-IVb in 4a ,

1a shows an induction hob with a hob plate in a plan view. The hob plate comprises a base plate 10a from a glass ceramic. The base plate 10a has a footprint 11a for cooking utensils. The footprint 11a is arranged horizontally in an operational state of the induction hob and points upward. On the base plate 10a are four heating zones 24a . 26a . 28a . 30a in a known manner by means of a printing 34a marked. The four heating zones 24a . 26a . 28a . 30a are intended for cooking food in a cookware. Each of the heating zones 24a . 26a . 28a . 30a is one below the base plate 10a arranged induction heating element (not shown) assigned, which heats up the raised cooking utensils in an operating condition and the food to be cooked at temperatures up to 180 ° C. In addition to the heating zones 24a . 26a . 28a . 30a is on the base plate 10a an area 22a as a holding surface 20a intended. The holding surface 20a is in the area 22a from at least one specially trained and from the heating zones 24a . 26a . 28a . 30a different warming zone 32a arranged. The warming zone 32a is by another imprint 36a on the base plate 10a marked. The holding surface 20a is intended to keep cooked food cooked. For controlling and displaying an operating status of the heating zones 24a . 26a . 28a . 30a and the warming zone 32a is an area of the footprint 11a as a user interface 37a formed, which comprises touch-sensitive controls and display elements.

1b shows a not to scale sectional view through the hob plate along a line Ib-Ib in 1a , At one of the footprint 11a opposite side of the base plate 10a is a heating conductor 12a on an outer surface 14a the base plate 10a firmly arranged. To clarify that the heating conductor 12a on the footprint 11a is arranged opposite side, is the heating conductor 12a in the plan view of the induction hob in 1a schematically drawn as a dashed line. The heating conductor 12a is in a vertical plan view of the footprint 11a essentially spiral in the form of a double spiral within the range 22a arranged. The heating conductor 12a heats the as holding surface 20a executed part of the footprint 11a in an operating condition to a temperature in a range of 90 ° C to 100 ° C. The heating conductor 12a is as a ceramic conductive coating 16a executed and using a screen printing process on the base plate 10a applied. At both ends of the heating conductor 12a are contact surfaces 38a . 40a formed. In a mounted state of the hob plate in the induction hob are against the contact surfaces 38a . 40a electrically conductive spring elements pressed, over which the heating conductor 12a is powered. One from the heating conductor 12a discharged heat flow passes through the base plate 10a to the holding surface 20a and from there to a set up cooking utensils.

In the 2a c, 3 . 4a and 4b three further embodiments of the invention are shown. The following descriptions are essentially limited to the differences between the embodiments, with respect to the same components, features and functions on the description of the other embodiments, in particular the 1a and 1b , can be referenced. To distinguish the embodiments, the letter a in the reference numerals of the embodiment in the 1a and 1b by the letters b, c and d in the reference numerals of the embodiments of 2a c, 3 . 4a and 4b replaced.

2a shows a further embodiment of a cooktop panel according to the invention with a base plate 10b , A holding surface 20b includes a complete half of a footprint 11b a base plate 10b the hob plate. From a user interface 37b seen from the hob plate takes the keep warm surface 20b the entire right half of the footprint 11b one. A heating conductor 12b is in a vertical plan view of the footprint 11b essentially looped below the holding surface 20b arranged. This arrangement allows a cooking operation of two heating zones 24b . 30b in a simultaneous holding operation of the holding surface 20b , Alternatively, another subdivision of a footprint can be selected.

2 B shows a not to scale sectional view through the hob plate along a line IIb-IIb in 2a , The heating conductor 12b is as a substantially pure metallic conductive coating 16b educated. One of the footprint 11b opposite side of the base plate 10b is in an area of the heating conductor 12b from an enameled protective layer 18b overdrawn.

2c shows a partial perspective view of the footprint 11b opposite side of the base plate 10b , The conductive coating 16b is by means of a sputtering process on the base plate 10b applied. This is the whole of the footprint 11b opposite side of the base plate 10b completely coated. Thereafter, by means of a laser ablation process, the heating conductor 12b with molded at both its ends contact surfaces 38b . 40b from the conductive coating 16b cut out.

3 shows a further embodiment of a cooktop panel according to the invention. It differs from the previous embodiment 2a -C by having a holding surface 20c over almost a whole set-up area 11c a base plate 10c the hob plate extends. Here, every half of the footprint 11c from one of these half assigned heating conductor 12c heated. Alternatively, more than two heat conductors can be used so as to provide a further subdivision of a footprint.

4a shows a further embodiment of a cooking field according to the invention. A subarea of a footprint 11d a base plate 10d again comprises a holding surface 20d , A heating conductor 12d is as a ceramic conductive coating 16d executed, which is applied by means of a screen printing process. As in 4b in a non-perspective sectional view along a line IVb-IVb in 4a shown is the heating conductor 12d in a largely grave-shaped depression 42d one of the footprint 11d the base plate 10d introduced opposite surface. The depression 42d is burned into the surface by a laser ablation process. The base plate 10d surrounds the heating conductor 12d thus at least partially. By having a thickness of the base plate 10d in an area above the heating conductor 12d is reduced, a favorable higher heat transfer can be achieved.

In alternative embodiments, a specially marked holding zone with a large-area holding surface, which extends over several heating zones, can be combined. Furthermore, it is conceivable that a heating conductor is formed by a conductor wire, which is applied to the surface instead of a conductive coating. Advantageously, the conductor wire then has a protective layer in the form of an insulation, in particular an insulating varnish. Furthermore, it is conceivable that a heating conductor is applied as a conductive coating with a protective layer on a footprint of a base plate. This can save energy.

LIST OF REFERENCE NUMBERS

10

 baseplate

11

 footprint

12

 heating conductor

14

 outer surface

16

 Conductive coating

18

 protective layer

20

 Warming surface

22

 Area

24

 heating zone

26

 heating zone

28

 heating zone

30

 heating zone

32

 Warming zone

34

 Oppression

36

 Oppression

37

 user interface

38

 contact area

40

 contact area

42

 deepening

Claims (13)

Hob plate with at least one base plate ( 10a -D) with a footprint ( 11a -D) for cooking utensils, characterized by an electric heating element ( 12a -D) attached to the base plate ( 10a -D) is fixed. Hob plate according to claim 1, characterized in that the heating conductor ( 12a -D) on an outer surface ( 14a -D) the base plate ( 10a -D) is arranged. Hob plate according to claim 2, characterized in that the outer surface ( 14a -D) the footprint ( 11a -D) is opposite. Hob plate according to claim 1 or 2, characterized in that the heating conductor ( 12a D) a conductive coating ( 16a -D) the base plate ( 10a -D). Hob plate according to claim 4, characterized in that the conductive coating ( 16a ; 16d ) is applied by means of a screen printing process. Hob plate according to claim 4, characterized in that the conductive coating ( 16b ; 16c ) is applied by means of a sputtering process. Hob plate according to one of the preceding claims, characterized by a protective layer ( 18b ; 18c ) on the heating conductor ( 12b ; 12c ). Hob plate according to one of the preceding claims, characterized in that the heating conductor ( 12a -D) is arranged at least in a partial region at least substantially loop-shaped and / or spirally and / or star-shaped. Hob plate according to one of the preceding claims, characterized in that the heating conductor ( 12a -D) is provided as a holding surface ( 20a -D) executed portion of the footprint ( 11a -D) to heat up. Hob plate according to claim 9, characterized in that the heating conductor ( 12a -D) is provided, the holding surface ( 20a -D) to a temperature between 60 ° C and 105 ° C. Hob plate according to claim 9 or 10, characterized in that the holding surface ( 20a ) in one area ( 22a ) of at least one specially designed and heated zone ( 24a . 26a . 28a . 30a ) different holding zone ( 32a ) is arranged. Hob plate according to one of the preceding claims, characterized in that the base plate ( 10d ) the heating conductor ( 12d ) at least partially encompasses. Hob, in particular induction hob, with a hob plate according to one of the preceding claims.

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