EP3066888A1

EP3066888A1 - Induction hob device

Info

Publication number: EP3066888A1
Application number: EP14806727.5A
Authority: EP
Inventors: Nicolas Blasco Rueda; Oscar Garcia-Izquierdo Gango; Ignacio Garde Aranda; Oscar Gracia Campos; Pablo Jesus Hernandez Blasco; Daniel Palacios Tomas
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2013-11-05
Filing date: 2014-10-27
Publication date: 2016-09-14
Anticipated expiration: 2034-10-27
Also published as: US20160262213A1; WO2015068077A1; US10694589B2; ES2535245B1; EP3066888B1; ES2535245A1; ES2747917T3

Abstract

The invention relates to an induction hob device (10) comprising at least one induction heating element (12) which is provided to heat cooking utensils and comprising at least one detection circuit (14) which is provided to co-operate with the at least one induction heating element (12) to detect cooking utensils. In order to provide a generic device with an advantageous construction, according to the invention the at least one detection circuit (14) is connected directly to the at least one induction heating element (12) independently of the operating mode.

Description

Induction hob device

The invention is based on an induction hob apparatus according to the preamble of claim 1.

From WO 2010/069788 A1 is already an induction cooktop device with an induction heating, which is intended for heating of cooking dishes set up, and with a detection circuit, which in cooperation with the

Induction heating is provided for a detection of erected cooking utensils, known. The induction heating element is connected via a relay either with a

Heating frequency unit or connected to the detection circuit. Of the

Detection circuit is thus connected only in the corresponding switching position of the relay with the induction heating.

The object of the invention is in particular to provide a generic device with an advantageous construction. 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 an induction hob apparatus with at least one induction heating element which is provided for heating cooking utensils, and with at least one detection circuit which, in cooperation with the at least one induction heating element, is provided at least for the detection of erected cooking utensils.

It is proposed that the at least one detection circuit is connected to the at least one induction heating element independently of an operating state. An "induction heating element" is to be understood as meaning, in particular, a part, in particular a subassembly, of an induction cooktop. An "induction heating element" is to be understood in particular as a wound electrical conductor which is flowed through in at least one operating state by high-frequency alternating current, in particular heating current. In particular, that is

Induction heating element designed to convert electrical energy into a magnetic alternating field, which is intended, in a metallic, preferably at least partially ferromagnetic, garland eddy currents and / or Ummagnetisierungseffekte cause, which are converted into heat.

Preferably, the induction heating element is intended to cause heating of the cooking utensil. Preferably, the induction hob device comprises at least two, in particular at least three, advantageously at least four, particularly advantageously at least eight, preferably at least ten, particularly preferably a plurality of induction heating elements. Under a "detection circuit" should

In particular, an electrical circuit can be understood, which is provided in response to mounted in an installed position above the induction heating Garware for changing at least one detection characteristic. In particular, the detection circuit is at least in an operating state of at least one

Flow through the detection current. In particular, the detection circuit is provided as a function of cooking utensils installed in an installed position above the induction heating element for changing at least one frequency of the detection current.

Alternatively, the detection circuit could be provided in response to a set up in an installed position above the induction heating Garware for changing at least one phase angle of the detection current. Also conceivable are further detection parameters that appear appropriate to a person skilled in the art. Preferably, the detection circuit is provided to be supplied by at least one sensor current supply unit, which is in particular formed separately from at least one power current supply unit to supply the at least one induction heating. Preferably, the

Induction hob device at least two, in particular at least three, advantageously at least four, more preferably at least eight, preferably at least ten, more preferably a plurality of detection circuits. Preferably, a number of induction heating elements and a number of detection circuits are at least substantially, in particular exactly the same. Alternatively, it is conceivable that a detection circuit with at least two, in particular with at least three, advantageously with at least four, particularly advantageously connected to a plurality of induction heating elements. The term "independent of an operating state" should be understood to mean, in particular, independently of at least one position of at least one switching element and / or independent of a current flow through the induction heating element

Operating state "directly" connected to the induction heater is intended in particular be understood that the detection circuit and the induction heating in any operating condition, in particular at least for alternating current form a closed circuit. In particular, in each heating operating state, electric current, in particular alternating current, flows through the closed circuit. In particular, the detection circuit in each operating state is flowed through by a detection current corresponding to a heating current. Independent of one

Operating state exists in particular at least one, in particular at least for alternating current, electrically conductive connection between the detection circuit and the induction heating. In particular, a connection between the

Detection circuit and the induction heater free of switching elements, in particular of relays and / or transistors. In particular, the term "provided" should be understood to mean specially programmed, designed and / or equipped.Assuming that an object is intended for a specific function should in particular mean that the object fulfills this specific function in at least one application and / or operating state and / or performs.

The embodiment according to the invention makes it possible to provide an induction hob unit with an advantageous construction. In particular, low production costs can be achieved. In particular, on switching elements for establishing a connection between the detection circuit and the

Induction heating be dispensed with. In particular, problems due to low current through contacts of a switching element, in particular a relay, can be avoided. In addition, a detection can advantageously be carried out independently of a switching position of a switching element, in particular of a relay.

Alternatively or in addition to the embodiment according to the invention is a

Induction hob with at least one induction heating element

proposed, the part is provided at least one power circuit and at least for heating cooking utensils, and with at least one

Detection circuit, which is provided at least for a detection of cooking utensils and in at least one operating state, the at least one induction heating, wherein the at least one detection circuit comprises at least one protection unit which is connected to the at least one induction heating element and branches off from the at least one power circuit. The protection unit is included in particular provided for independently of an operating state, in particular at least in a heating operating state, at least the at least one

Detection circuit to protect against external voltages. In particular, the at least one protection unit is provided to at least substantially prevent the penetration of, in particular, high-frequency heating current into the detection circuit. Preferably, a value of a frequency differs from one

Detection current of a value of a frequency of a heating current by a factor of at least 10, in particular of at least 100, advantageously of at least 500, more preferably of at least 1000. "External voltages" should be understood in particular voltages that advantageously in an operating state via at least one Heating frequency unit and / or over the at least one

Induction heating fall off. Alternatively or additionally, under "outer

Voltages "are understood in particular to be voltages which are in particular intended to be used in an operating state for operating the at least one induction heating element

Protection unit is provided to "at least substantially prevent the ingress of particular high-frequency heating current in the detection circuit, should be understood in particular that the protection unit is intended to a proportion of not more than 50%, in particular of at most 30%, preferably of maximum 15%, particularly advantageously of not more than 10%, preferably of not more than 5% and more preferably of not more than 2%, of heating current striking the protective unit on one side from passing, in particular reaching a second side facing away from the first side, to prevent the protective unit As a result, in particular an induction hob device with an advantageous construction can be provided, wherein advantageously an accurate detection of cooking utensil can be achieved.

It is further proposed that the induction hob device comprises at least one heating frequency unit for supplying the at least one induction heating element, wherein the at least one detection circuit is a connection between the at least one heating frequency unit and the at least one

Induktionsheizelement is branched off. A "heating frequency unit" should in particular be understood to mean an electrical unit which has an oscillating electrical signal, preferably with a frequency of at least 1 kHz, in particular of at least 10 kHz, advantageously of at least 20 kHz and in particular of not more than 100 kHz generates at least one induction heating element. In particular, the heating frequency unit is provided to provide a, required by the induction heating, maximum electrical power of at least 100 W, in particular at least 500 W, advantageously at least 1000 W and preferably at least 1500 W. The Heizfrequenzeinheit advantageously comprises at least one inverter, preferably at least two, preferably in series, bidirectional unipolar switches, which are formed in particular by a transistor and a parallel diode, and particularly advantageously at least one parallel to the bidirectional unipolar switches switched buffer capacity, which is in particular formed by at least one capacitor. A voltage tap of the heating frequency unit is arranged in particular at a common contact point of two bidirectional unipolar switches.

In particular, the at least one heating frequency unit and the at least one induction heating element form the at least one at least in an operating state

Power circuit off. A "connection" between the heating frequency unit and the induction heating element should in particular be understood as bridging at least one distance between the heating frequency unit and the induction heating element, which is electrically conductive in at least one operating state By means of the phrase that the detection circuit is "branched off" from a connection between the heating frequency unit and the induction heating element, it should be understood in particular that at least one and preferably exactly one electrically conductive contact point exists by means of which the detection circuit is connected to the Connection between the heating frequency unit and the induction heater is connected. This can be achieved in particular a precise detection of erected on the induction heating cookware.

In addition, it is proposed that the induction hob unit comprises at least one protection unit which is provided, at least the at least one detection circuit, independently of an operating state, in particular at least in a heating operating state, in particular during operation of the at least one

Induction heating occurring, external voltages to protect. This can in particular a penetration of high-frequency alternating current in the

Detection circuit can be avoided. In particular, components that are suitable for Low voltage are designed to be used instead of components that are designed for high performance, which in particular a low-cost design can be achieved.

Furthermore, it is proposed that the at least one protection unit be independent of an operating state between an input of the at least one

Detection circuit and a branch of the connection between the at least one Heizfrequenzeinheit and the at least one induction heating element is connected. In particular, the protection unit is independent of one

Operating state connected to a detection circuit side facing the branch of the connection between the heating frequency unit and the induction heating. In particular, the protection unit is independent of one

Operating state arranged outside the power resonant circuit. This can be achieved in particular a durable design.

It is also proposed that the at least one protection unit has at least one capacitor. In particular, the capacitor differs from a capacitor of the power resonant circuit, in particular of one

Attenuation capacitor and / or a resonance capacitor. As a result, in particular a cost-effective design can be achieved.

In addition, it is proposed that the at least one detection circuit and the at least one induction heating element be at least in an operating state,

form a resonant circuit, in particular outside a Heizbetriebszustands.

Under a "resonant circuit" in particular a resonant electric

Circuit can be understood, which comprises at least the induction heating element and at least one capacitance, which is in particular part of the detection circuit.

In particular, the detection circuit and the induction heating element are provided to perform electrical oscillations at least in one operating state.

As a result, particularly set up cooking utensils can be detected precisely.

Furthermore, it is proposed that the induction hob unit comprises a control unit which is provided to determine at least one cooking appliance characteristic as a function of a natural frequency change of the at least one detection circuit. Under a "control unit" is intended in particular an electronic unit be understood, which is preferably at least partially integrated in a control and / or regulating unit of an induction hob and which is preferably provided to control at least the heating frequency unit and / or to regulate.

The control unit preferably comprises a computing unit and, in particular in addition to the computing unit, a memory unit with a control and / or regulating program stored therein, which is intended to be executed by the computing unit. In particular, the control unit has at least one amplifier at least to an amplification of the detection current. In particular, the control unit has at least one analog-to-digital converter at least for a conversion of the detection current. In particular, the cooking utensil characteristic is designed as the presence and / or absence of erected cooking utensils. In particular, the cooking utensil characteristic is designed as a size and / or shape and / or material of cooking utensils. Alternatively, further embodiments of the cooking appliance characteristic appearing appropriate to a person skilled in the art are conceivable. This can be achieved in particular a high level of comfort for an operator. In particular, the cooking utensil characteristic can be determined exactly.

Furthermore, it is proposed that the at least one detection circuit is provided for cooking utensils, in particular exclusively, outside one

Heating mode to detect. In particular, the heating frequency unit, in particular the buffering capacity of the heating frequency unit, is provided to prevent, in particular to block, the detection of upright cooking utensils in the heating operating state. In particular, the buffering capacity is provided to short-circuit the detection circuit in the heating mode. As a result, in particular a durable and / or cost-effective design can be achieved. Further advantages emerge from the following description of the drawing. In the drawings, embodiments of the invention are shown. The drawing, 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 meaningful further combinations. Show it: Fig. 1 shows an induction hob with an inventive

Induction hob in a schematic plan view,

2 shows an application example of the induction cooktop apparatus from FIG. 1 in a schematic illustration,

3 shows a detail of the induction cooktop apparatus from FIG. 1 in a greatly simplified schematic representation and FIG

Fig. 4 shows a detail of an alternative embodiment of

induction hob according to the invention from Fig. 1 in a highly simplified, schematic representation. Fig. 1 shows an induction hob 30 with an inventive

Induction hob 10. The induction hob 30 has a base body 32 for setting up cooking utensils. The main body 32 is formed as a hob plate. The main body 32 forms a cooking surface. The induction hob 30 includes an operating unit 34 for inputting and / or selecting

Operating parameters, such as a heating power and / or a Heizleistungsdichte and / or a heating zone. The operating unit 34 is provided for outputting a value of an operating parameter to an operator. The induction cooktop apparatus 10 comprises a control unit 28, which is provided to execute actions and / or to change settings in dependence on operating parameters entered by the operating unit 34.

The induction hob device 10 comprises a plurality of induction heating elements 12, which are provided for heating up cooking utensils (see FIG. 2). In FIG. 2, for the sake of clarity, of components and / or objects which are present several times, only one is provided with a reference numeral. The induction heating elements 12 form a variable cooking surface area. The induction heating elements 12 form a hob matrix. In an alternative embodiment, it is conceivable that the

Induction heating are designed as classic induction heating and form a classic cooking surface. In this case, each induction heating element could form a separate heating zone for heating up cooking utensils. The induction hob unit 10 comprises a plurality of heating frequency units 16 for supplying the induction heating elements 12. The heating frequency units 16 are part of a power current supply unit 48, which is used to supply the Induction heating 12 is provided. Each heating frequency unit 16 includes an inverter. Each heating frequency unit 16 includes two series-connected bidirectional unipolar switches. Each heating frequency unit 16 comprises two buffer capacities 42 connected in series. In each case one buffer capacity 42 is connected in parallel with one of the unipolar switches. In an operating state, the generate

Heizfrequenzeinheiten 16 high-frequency alternating current to a supply of the induction heating elements 12. The high-frequency alternating current is as a heating current

educated. The heating current has a frequency of several kilohertz.

For example, in a heating mode, the heating current could have a frequency between 25 kHz and 75 kHz. Alternatively, further frequencies which appear reasonable to a person skilled in the art are conceivable.

The heating frequency units 16 are connected by means of an electrically conductive connection 18 to the induction heating elements 12. The induction heating elements 12 are connected to the heating frequency units 16 facing away from connection points 46 via a

Resonance unit 56 connected to ground. The Heizfrequenzeinheiten 16 form in a heating mode with the induction heaters 12 and a part of

Resonance unit 56 from a power circuit. The induction hob device 10 includes the resonance unit 56. The resonance unit 56 includes for each

Induction heating 12 a resonance capacity. Each resonant capacitance has two capacitors.

The induction hob device 10 comprises a circuit unit 36 which is provided to make or break the connection 18 between the heating frequency units 16 and the induction heating elements 12. The circuit unit 36 comprises a plurality of switching elements, wherein in each case one switching element in one of

Connections 18 between one of the heating frequency units 16 and one of the

Induction heating 12 is arranged. The circuit unit 36 is of the

Control unit 28 controllable. Alternatively, an embodiment while avoiding a circuit unit is conceivable, wherein the heating frequency units and the

Induction heating are connected directly to each other (see Fig. 4). In this case, the connection between the heating frequency units and the induction heating elements is uninterrupted, in particular electrically independent of an operating state. The induction hob apparatus 10 includes a plurality of rectifiers 38 connected to a phase 40 of a utility network (see Fig. 2). The rectifiers 38 rectify an AC coupled through phase 40. In each case a rectifier 38 is connected to two Heizfrequenzeinheiten 16. Two each

Heizfrequenzeinheiten 16 are connected via a rectifier 38 to the phase 40 of

Supply network connected.

The induction hob device 10 comprises a plurality of detection circuits 14. Each detection circuit 14 is provided in cooperation with a respective induction heating element 12 for the detection of erected cooking utensils. Everyone

Detection circuit 14 is directly connected to one of the induction heaters 12 regardless of an operating condition (see Fig. 3). The detection circuits 14 are independent of a switching position of the circuit unit 36 directly with the

Induction heating 12 connected. In the present embodiment, each detection circuit 14 with one of the heating frequency unit 16 facing

Connection point 44 of the induction heating 12 connected. The detection circuits 14 are branched off from the connections 18 between the heating frequency units 16 and the induction heating elements 12. The branches 24 of the connections 18 between the heating frequency units 16 and the induction heating elements 12 are arranged between the heating frequency units 16 facing connection points 44 and the circuit unit 36.

The induction hob device 10 includes a plurality of protection units 20, which are provided to protect the detection circuits 14 from external stresses regardless of an operating state. The protection units 20 are connected to the detection circuits 14 facing sides of the branches 24, regardless of an operating condition. The protection units 20 are connected independently of an operating state between an input 22 of the detection circuits 14 and the branches 24 of the connections 18 between the heating frequency units 16 and the induction heating elements 12. The protection units 20 each have a capacitor 26. In the present embodiment, the

Capacitors 26 capacitances of substantially 100 pF on. The protection units 20 have a resistance of between 200 kΩ and 600 kΩ in a heating operation state for the heating current. Alternatively, preferably, capacitors with a Capacity in a range of 50 pF to 150 pF conceivable. Additionally or alternatively, the protection unit could be any series and / or parallel connection of

Have capacitors. In addition, as an alternative to a capacitor, further protection units which appear sensible to a person skilled in the art are conceivable. The induction hob device 10 comprises a sensor current supply unit 50, which is provided to supply the detection circuits 14 with detection current. The sensor power supply unit 50 is provided to supply the control unit 28. The sensor power supply unit 50 and the power power supply unit 48 are formed separately. The sensor power supply unit 50 is connected to a phase 52 of the supply network. The phase 52 to which the sensor current supply unit 50 is connected is different from the phase 40 to which the power current supply unit 48 is connected. Alternatively, it is conceivable that the power current supply unit and the sensor power supply unit are connected to the same phase. In both cases, the induction heating elements 12 and the detection circuits 14 become independent

supplied from each other.

In a method of operating the induction hob device 10 is described in

Co-operation of the detection circuits 14 and the induction heating 12 detected cooking utensils detected. The detection circuits 14 act in an operating state, the induction heating 12 with high-frequency

AC, which is designed as a detection current. The detection current has a frequency of a few MHz. For example, the detection current in an operating state could have a frequency between 1.5 MHz and 2.2 MHz. Alternatively, further frequencies which appear reasonable to a person skilled in the art are conceivable. The

Protection units 20 have a resistance of between 0.7 kQ and 1 kΩ for the detection current. In the operating state forms one of

Detection circuits 14 and one of the induction heating 12 each from a resonant circuit.

In the case of an induction heating element 12 that is free of cooking utensils installed, a frequency of the detection current is substantially 1.5 MHz. When set up on the induction heater 12 Garware increases the frequency of the detection current depending on size, shape and material of set up Cooking containers. In each case an output 54 of one of the detection circuits 14 is connected to the control unit 28. The output 54 of the detection circuit 14 is connected via the control unit 28 to ground. The control unit 28 determines a function of a natural frequency change of the detection circuit 14 a

Gargeschirrkenngröße. The control unit 28 determines based on a size of the

Natural frequency change of the detection current Size, shape and material of

set up cooking utensils.

In an operating state in which the detection circuits 14 detect cooking utensils installed, the connections 18 between the heating frequency units 16 and the induction heating elements 12 are interrupted by the circuit unit 36. One

Operating state in which the detection circuits 14 detect cooking utensils set up is formed separately from a heating operating state in which the

Induction heating elements heat up 12 cooking utensils installed.

In a heating mode, at least one of the connections 18 between the heating frequency units 16 and the induction heating elements 12 is established. In a heating mode, those of the connections 18 between the

Heizfrequenzeinheiten 16 and the induction heating 12 branched off

Detection circuits 14 short-circuited by the buffer capacitances 42 of the heating frequency unit 16. The buffer capacities 42 are at a frequency of

Detection current to a low impedance, which directly with the

Induktionsheizelementen 12 connected detection circuits 14 are shorted. In a heating operation state, high-frequency alternating currents having a substantially same frequency as the heating currents flow through the oscillation circuits formed by the induction heating elements 12 and the detection circuits 14. The

Detection circuits 14 detect installed cooking utensils outside of one

Heizbetriebszustands. Outside of a heating operating state flow through the of the induction heating 12 and the detection circuits 14 formed

Oscillation circuits detection currents.

In an alternative embodiment, it is conceivable that a number of

Detection circuits is less than a number of induction heating elements. In this case, the detection circuits by multiplexing with several

Induktionsheizelementen be connected, wherein the protective unit between the Multiplexer and the induction heating could be arranged. It is also conceivable that the protection unit between the multiplexer and the input of the

Detection circuit is arranged.

As an alternative to connecting the outputs of the detection circuits to ground, it is conceivable that the outputs of the detection circuits with the

Heating frequency units facing away from connection points of the induction heating are connected. This could be between the outputs of the detection circuits and the heating frequency units facing away from the connection points

Induction heating each a further protection unit, in particular in addition to the protection unit, which branches off from the connection between the heating frequency unit and the induction heating, may be provided.

For example, it is conceivable that the control unit is provided to a

Heating operation state, in particular to allow operation of the induction heating, in particular exclusively when the cooking utensils are set up and to prevent in particular in gargeschirrfreien state.

reference numeral

10 induction hob device

12 induction heating element

14 detection circuit

16 heating frequency unit

18 connection

20 protection unit

22 entrance

24 diversion

26 capacitor

28 control unit

30 induction hob

32 basic body

34 operating unit

36 circuit unit

38 rectifier

40 phase

42 buffer capacity

44 connection point

46 connection point

48 power supply unit

50 sensor power supply unit

52 phase

54 output

56 resonance unit

Claims

claims

Induction hob device with at least one induction heating element (12), which is provided for heating cooking utensils, and with at least one detection circuit (14), which is provided in cooperation with the at least one induction heating element (12) for the detection of cooking utensils, characterized in that the at least one detection circuit (14) is directly connected to the at least one independent of an operating state

Induction heating element (12) is connected.

Induction hob device according to claim 1, characterized by

at least one heating frequency unit (16) for supplying the at least one induction heating element (12), wherein the at least one

Detection circuit (14) of a connection (18) between the at least one Heizfrequenzeinheit (16) and the at least one induction heating element (12) is branched off.

Induction hob device according to one of the preceding claims, characterized by at least one protection unit (20) which is intended to protect at least the at least one detection circuit (14) from external stresses, irrespective of an operating condition.

Induction hob device according to claims 2 and 3, characterized in that the at least one protection unit (20) is independent of an operating state between an input (22) of the at least one detection circuit (14) and a branch (24) of the connection (18) between the at least one heating frequency unit (16) and the at least one induction heating element (12) is connected.

5. Induction hob device at least according to claim 3, characterized

characterized in that the at least one protection unit (20) has at least one capacitor (26).

6. Induction hob device according to one of the preceding claims,

characterized in that the at least one detection circuit (14) and the at least one induction heating element (12) at least in one

Operating state form a resonant circuit.

7. Induction hob device according to one of the preceding claims,

characterized by a control unit (28) provided for as a function of a natural frequency change of the at least one

Detection circuit (14) to determine at least one Gargeschirrkenngröße.

8. Induction hob device according to one of the preceding claims,

characterized in that the at least one detection circuit (14) is provided to detect cooking utensils outside a heating operating condition.

9. Induction hob with at least one induction hob device (10) according to any one of claims 1 to 8.

10. A method for operating an induction hob device (10), in particular according to one of claims 1 to 8, with at least one induction heating element (12) and at least one detection circuit (14) which, independently of an operating state, is connected directly to the at least one induction heating element (12) is, wherein in a cooperation of the at least one detection circuit (14) with the at least one induction heating element (12) set up cooking utensils is detected.