Kitchen utensil powered by induction hob

Abstract

Induction cookware powered by an induction cooktop. The invention relates to the power supply of cookware or containers for induction cooktops. The cookware or container (U) for induction cooktops according to the invention comprises at least one receiving induction coil (BR) to capture the energy emitted by an induction coil (BI) of an induction cooktop (PC). It then becomes possible to power, for example, an electronic circuit or a DC electric motor that rotates a mixing shaft. For the most sophisticated models, it also becomes possible to establish bidirectional communication between the electronics of the cooktop and the electronics of the cookware or container. Figure to be published with the abstract: Fig. 4.

Description

Title of the invention: Kitchen utensil powered by an induction hob

[0001] FIELD OF THE INVENTION TO WHICH THE INVENTION RELATES

[0002] The invention relates to the field of kitchen utensils or containers for induction hobs, their electrical power supply. PREVIOUS ART

[0003] In the case of a cooking appliance comprising one or more induction plates, heat is created by the magnetic field which heats the magnetic elements such as magnetic stainless steel present in the cooking utensil or container.

[0004] As shown [Fig. 1], the bottom (F) of the cooking utensil or container, in this case a frying pan, comprises several layers. The first layer (F1) is a layer of magnetic stainless steel which will create the heat, the second layer (F2) is a layer of aluminum which will diffuse the heat created, the third layer (F3) will be in contact with the food and will be made of non-magnetic stainless steel.

[0005] The induction coil (BI) will generate an electromagnetic field which will heat the magnetic elements by eddy current, in this case the layer (Fl).

[0006] Kitchen utensils or cooking plate containers are usually devoid of electronics or electrical accessories.

[0007] If this were the case, it would be possible for low powers of a few watts to power them by a battery and for higher powers to power them on the mains with alternating current 50 Hz 220 volts or other depending on the country.

[0008] The battery solution has the disadvantage of its size and the need to replace the batteries, and therefore also the need for a case and a cover.

[0009] The mains power solution has the disadvantage of the presence of the mains cord on the hob.

[0010] BRIEF DESCRIPTION OF THE INVENTION

[0011] The kitchen utensil or container for an induction hob according to the invention comprises at least one induction coil.

[0012] This receiving induction coil captures the energy from an induction hob (PC) on which the cooking utensil or induction hob container is placed.

[0013] The kitchen utensil or container may comprise a plurality of receiving induction coils.

[0014] According to one embodiment, at least one receiving induction coil has turns distributed angularly over an angle sector.

[0015] According to one embodiment, at least one receiving induction coil is integrated into the wall of the kitchen utensil or container but it can also be integrated into a strapping of the kitchen utensil or container.

[0016] In the latter case, it may be advantageous for at least one receiving induction coil to be produced on a flexible printed circuit.

[0017] In terms of operation, the receiving induction coil makes it possible to power a low voltage electronic circuit.

[0018] Preferably, the low voltage electronic circuit is integrated into the means for gripping the kitchen utensil or container.

[0019] According to a last embodiment, the receiving induction coil in a larger size makes it possible to power an electric motor.

[0020] For the most sophisticated models, it becomes possible to establish two-way communication between the electronics of the hob and the electronics of the kitchen utensil or container. Brief description of the drawings

[0021] Other characteristics and advantages of the invention will appear on reading the detailed description which follows, for the understanding of which reference will be made to the attached drawings.

[0022] [Fig. 1] shows a pan for induction hob in a classic configuration without electronics or electrical accessories.

[0023] [Fig.2] shows a pan for an induction hob having a low power receiving induction coil in its center.

[0024] [Fig.3] shows a pan for an induction hob having a low power receiving induction coil integrated into its wall.

[0025] [Fig.4] shows a pan for an induction hob having a high power receiving induction coil integrated under the bottom of the pan. DETAILED DESCRIPTION OF THE INVENTION

[0026] The kitchen utensil or container (U) for an induction hob according to the invention comprises at least one induction coil.

[0027] This induction coil is designed to be a receiving induction coil for picking up energy from an induction hob emitted by an induction coil thereof.

[0028] According to a first illustrated embodiment [Fig. 1], the receiving induction coil (BR) is a flat coil of the order of 16 turns of a Litz wire of approximately 1 millimeter in diameter.

[0029] The receiving induction coil (BR) is in this first embodiment placed in the center of the bottom (F) in a cavity without the presence of the magnetic layer (Fl) which fits into a diameter of approximately 5 centimeters.

[0030] It remains protected from contact with food by the layer (F3) for example in austenitic non-magnetic stainless steel, type 304 grade.

[0031] Thus this coil can be integrated into the thickness of the bottom (F) but will only capture a small part of the power of the induction plate, up to a few watts.

[0032] According to a second illustrated embodiment [Fig.2], the receiving induction coil (BR) is a rectangular flat coil of the order of 16 turns of a Litz wire of approximately 1 millimeter in diameter integrated or close to the wall (P).

[0033] In order for this receiving induction coil (BR) to be able to capture energy emitted by the induction coil (BI) of the cooking plate, it is necessary on the one hand that the wall (P) is not made of magnetic material, for example aluminum or non-magnetic stainless steel and on the other hand that the magnetic layer (Fl) does not cover the entire surface of the bottom (F).

[0034] For this purpose, the layer of magnetic material (Fl) is only present at the location of the six rectangles shown in dotted lines in [Fig.2].

[0035] In fact, sufficient presence of magnetic material (Fl) is required to heat the bottom (D) of the kitchen utensil or container (U) and for it to be detected by the detection of the presence of a kitchen utensil on the cooking plate (PC)

[0036] In this configuration, the energy captured by the receiving induction coil (BR) will not be uniform depending on the angular orientation over 360°.

[0037] It is then preferable that the kitchen utensil or container (U) comprises a plurality of receiving induction coils (BR).

[0038] These receiving induction coils (BR) are angularly distributed over 360°.

[0039] Alternatively, as shown [Fig.2], it is possible to use at least one coil with turns distributed angularly over an angle sector.

[0040] This or these receiving induction coils can be physically integrated into the thickness of the wall (P) but it is also possible to integrate them into a strapping of the kitchen utensil or container (U).

[0041] It remains possible to produce this receiving induction coil or coils (BR) in the form of a flexible printed circuit such as polyamide or kapton supports.

[0042] In these first two embodiments, the captured energy is a few watts.

[0043] The current collected at the terminals of the third induction coil (BI3) is an alternating current at the frequency of the induction coil (BI2), typically around 25 kHz.

[0044] The set of two coils (BI, BR) behaves like a transformer and the voltage received can be of the order of a few volts.

[0045] The alternating current thus obtained can be directly used as an example to visualize the power of the cooking plate for the user. This can take the form of the intensity of a bulb, the movement of a needle, the rotation of an element.

[0046] The alternating current thus obtained can also be used to power a low-voltage electronic circuit. In this case, the alternating current must be rectified by a diode bridge, stored in a high capacity to absorb, for most models, the cyclic modulation used by the cooking plate to modulate the power of the induction coil according to the setting made by the user.

[0047] The electrical power thus transmitted is in the form of a direct voltage across a capacitor which then powers a voltage regulator, or even a simple zener diode, to produce the stabilized voltage required by the electronic circuit.

[0048] The electronic circuit can, for example, display the temperature of the bottom of the pan (U) measured by a thermistor, i.e. by a resistor with a positive or negative temperature coefficient or by a thermocouple.

[0049] It will also make it possible to display the heating speed, which is difficult to assess in the case of an induction hob, unlike, for example, a gas cooker where the user can directly see the gas power setting.

[0050] Preferably the electronics will be located in the means of gripping the kitchen utensil or container (U) which generally remains at low temperature, in this case as illustrated [Fig.3] in the handle of the frying pan (U) with its control (C) and its display (D).

[0051] Advantageously, the gripping means will be removable and connected to the rest of the cooking appliance by a connector comprising at least the two terminals of the receiving induction coil (BR), and for example in the case of temperature measurement at the two terminals of the thermistor.

[0052] Thus the electronics will be less exposed and will not have to withstand the washing conditions of a dishwasher unlike the rest of the kitchen utensil or container (U) which can be put in the dishwasher.

[0053] In a third illustrated embodiment [Fig.4], for greater energy requirements, the receiving induction coil is similar to the induction coil (BI) of the cooking plate.

[0054] This will be, for example, an induction coil of 24 turns of Litz wire with a diameter of around 5 millimeters.

[0055] This receiving induction coil (BR) cannot be integrated into the thickness of the bottom (F) and will be placed under the bottom (F) which will therefore be raised by a few millimeters.

[0056] It is then advantageous for the kitchen utensil or container (U) to preferably have at its base magnetic material (M) capable of channeling the magnetic flux from the induction coil (BI) towards the bottom (F).

[0057] For this, the magnetic material (M) of the kitchen utensil or container (U) is distributed between a central part (MC) and a peripheral part (MP) opposite the induction coil (BI).

[0058] This magnetic material (M) may be a magnetic material of the type of that of the layer (Fl). It may for example be a martensitic stainless steel, grade 440C.

[0059] This variant also remains compatible with a temperature measurement in the center of the bottom (F) by the cooking plate (PC) due to the presence of the central part (MC).

[0060] It is also possible that the cooking robot (R) has a soft magnetic material instead of the previous magnetic material. This soft magnetic material will channel the magnetic flux without heating due to eddy currents.

[0061] Preferably, to avoid heat transmission, the soft magnetic material is spaced from the bottom (F) by an air gap.

[0062] These soft magnetic materials are those used in transformers.

[0063] Advantageously, the soft magnetic material comprises ferrite. This may be molded ferrite which may be brittle or ferrite embedded in a plastic material such as plastoferrite.

[0064] The set of two coils (BI, BR) behaves like a transformer and the voltage received can be of the order of the supply voltage of the coil if the number of turns is similar. The alternating current thus obtained can be rectified by a diode bridge then stored in a high capacity to absorb for most models the cyclic modulation used by the cooking plate to modulate the power of the induction coil according to the setting made by the user. The electrical power thus transmitted is in the form of a direct voltage at the terminals of a high capacity.

[0065] It then becomes possible to power, for example, a continuous electric motor which rotates a mixing shaft with blades to mix the food, or the blades of a fan, to heat locally or to cool by the Peltier effect, or to recharge a rechargeable battery.

[0066] For the most sophisticated versions, it also becomes possible to install bidirectional communication between the electronics of the cooking plate (PC) and the electronics of the kitchen utensil or container (U) which allows reciprocal identification, control of the cooking process and control of the energy transfer by the coupling of the two induction coils, transmitter (BI) and receiver (BR). Industrial application

[0067] In terms of industrial application, the invention applies to the electrical supply of kitchen utensils or containers for induction hobs.

[0068] The present invention is in no way limited to the embodiments described and shown, but those skilled in the art will be able to provide any variation in accordance with its spirit for a range of products in different fields.

Claims

Claims

1. Kitchen utensil or container (U) for induction hob characterized in that it comprises at least one induction receiving coil (BR) integrated in the wall of the kitchen utensil or container (U) or close to the wall of the kitchen utensil or container (U), that the wall (P) of the kitchen utensil or container (U) is not made of magnetic material and that a magnetic layer (Fl) does not cover the entire surface of the bottom (F).

2. Kitchen utensil or container (U) according to claim 1 characterized in that the receiving induction coil (BR) captures the energy from an induction cooking plate (PC) by being positioned at the level of the wall (P), inside or close to this wall (P).

3. Kitchen utensil or container (U) according to any one of claims 1 to 2 characterized in that at least one receiving induction coil (BR) has turns distributed angularly over an angle sector.

4. Kitchen utensil or container (U) according to any one of claims 1 to 2, characterized in that at least one receiving induction coil (BR) is integrated into a ring of the kitchen utensil or container (U).

5. Kitchen utensil or container (U) according to any one of claims 1 to 4, characterized in that at least one receiving induction coil (BR) is produced on a flexible printed circuit.

6. Kitchen utensil or container (U) according to any one of claims 1 to 5 characterized in that the receiving induction coil (BR) supplies a low voltage electronic circuit.

7. Kitchen utensil or container (U) according to claim 6 characterized in that the low voltage electronic circuit is integrated into the gripping means of the kitchen utensil or container (U).

8. Kitchen utensil or container (U) according to claim 7 characterized in that there is a bidirectional communication between the electronics of the cooking plate (PC) and the electronics of the kitchen utensil or container (U).

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