EP3262895A1

EP3262895A1 - Induction cooking appliance with improved cooking performance

Info

Publication number: EP3262895A1
Application number: EP15706254.8A
Authority: EP
Inventors: Serdar Gokhan DOGANAY; Selcuk SOYYIGIT; Gamze DAG; Ugur Camli
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2015-02-26
Filing date: 2015-02-26
Publication date: 2018-01-03
Also published as: WO2016134779A1

Abstract

The present invention relates to an induction cooking appliance (1) comprising a top surface (2) which has a flexible zone (3, 4, 5) with two side-by-side subzones (9), two induction coils (11), two driving units each for driving a corresponding coil (11) within a power range and a control unit (12) with a flexible mode. In the induction cooking appliance (1) of the present invention, the control unit (12) allows in the flexible mode a user to select the two subzones (9) and a common power level inside or outside said power range and turns each of the driving units corresponding to the selected two subzones (9) ON/OFF in accordance with a respective routine in which each corresponding induction coil (11) is driven at a respective power level within said power range such that the average power for the two selected subzones (9) over a period equals to the common power level.

Description

INDUCTION COOKING APPLIANCE WITH IMPROVED COOKING PERFORMANCE

The present invention relates to an induction cooking appliance, in particular to a so-called “flexible” induction cooking appliance in which two individual subzones each for separately heating a comparatively small cookware can be combined into a single zone for jointly heating a comparatively large cookware.
Induction cooking appliances have become increasingly more favored as they enable a relatively energy-efficient way of cooking food. In order to increase the customer convenience, induction cooking appliances are usually provided with cooking zones which can be flexibly combined to match with various cookwares having different sizes and shapes. Such flexible induction cooking appliances are commonly known. A flexible induction cooking appliance generally comprises a top surface which has a flexible zone for inductively heating a comparatively large cookware, wherein the flexible zone includes two side-by-side subzones each for inductively and individually heating a comparatively small cookware, two induction coils which are respectively arranged under the two subzones and two driving units each for driving a corresponding induction coil at one of a plurality of preset power levels which define a discrete power range. In the flexible induction cooking appliance, the control unit generally allows, in the flexible mode, a user to combine the two subzones so as to jointly heat a comparatively large cookware and to select a preset power level. The control unit generally causes in the flexible mode the driving units of the combined two subzones to drive the corresponding induction coils respectively at the selected preset power level. In the flexible induction cooking appliances the available preset power levels are usually limited. In the flexible induction cooking appliance, the driving units generally comprise quasi-resonant inverters which have limited regulation ranges for setting the power levels. The minimum settable power level in the quasi-resonant inverter is commonly about 700 Watts to 800 Watts. Resonant half-bridge inverters are also commonly used in the flexible induction cooking appliances. The resonant half-bridge inverters have improved regulation ranges for setting the power levels, but are relatively cost-intensive.
A drawback of the flexible induction cooking appliance is that some food products such as chocolate which particularly require gentle cooking conditions can easily scorch when they are jointly heated through the subzones of the flexible zone even when the minimum settable power level is selected.
An objective of the present invention is to provide an induction cooking appliance which overcomes the aforementioned drawbacks of the prior art in a cost-effective way and which enables an improved cooking performance.
This objective has been achieved by the induction cooking appliance as defined in claim 1. Further achievements have been attained by the subject-matters respectively defined in the dependent claims.
In the induction cooking appliance of the present invention, the control unit allows in the flexible modes the user to select two or more than two side-by-side subzones in the same flexible zone and a common power level. In the induction cooking appliance of the present invention, the common power level is not limited to the power range of the individual driving units and can assume, in the flexible modes, values which lie inside or even outside said power range depending on the user-selection. In the induction cooking appliance of the present invention, the control unit turns in the flexible mode each of the driving units which correspond to the selected side-by-side subzones ON or OFF in accordance with a respective routine in which each corresponding induction coil is driven at a respective power level within said power range such that the average power for the selected side-by-side subzones over a predetermined period equals to the respectively selected common power level.
With the present invention, the users are enabled to more flexibly heat food products in a relatively broad power range which extends across the upper or lower limits of the power range of the individual driving units of the induction cooking appliance. With the present invention, particularly the food products which require gentle heating conditions can be treated more adequately. Thereby, the risk of scorching has been eliminated or reduced as much as possible. Thus, with the present invention, the cooking performance of the induction cooking appliance at relatively low power levels has been improved. With the present invention also the usability of the induction cooking appliance has been further improved. Thereby, the customer satisfaction can be further increased.
In the present invention the user can initiate one or more than one instances of flexible modes for cooking in a same flexible zone and separately therefrom, if desired, concurrently in another flexible zone. For instance, in the flexible modes, the user can select in one of the flexible zones with four side-by-side subzones, the two rear side-by-side subzones and a respective common power level and independently therefrom the two front side-by-side subzones and another respective common power level. Of course, each instance of flexible mode can be conducted concurrently with one or more than one instances of single modes for cooking in an individual subzone of any flexible zone and separately therefrom, if desired, concurrently in an individual subzone in any other flexible zone. For instance, in the flexible mode, the user can select in one of the flexible zones with four side-by-side subzones, the two rear side-by-side subzones and a respective common power level and independently therefrom in the single mode, the front subzone and another respective common power level.
In an embodiment, the flexible modes include a flexible mode for gentle cooking. When the flexible mode for gentle cooking is activated, then in the ON/OFF routines the corresponding induction coils are driven at power levels which are as close as possible to the lowest power level of the power range of the individual driving units. Thereby, the food products can be gently cooked and prevented from experiencing instantaneously high temperatures in the flexible mode. In alternative versions of this embodiment, the flexible mode for gentle cooking is activated when the user selects a common power level which is close to, or particularly smaller than the lowest power level of the power range of the individual driving units.
In the present invention, the ON/OFF routines in the flexible/single modes can be defined in many different ways. During the ON/OFF routines in the flexible modes some or all of the corresponding driving units can be turned in various intervals of the predetermined period simultaneously ON or OFF. The predetermined periods may comprise one or more than one interval. The intervals may have same or different durations. In another embodiment, in the flexible modes, the corresponding driving units are turned, in some or in all of the intervals of the predetermined period, sequentially ON. Thereby, the food products inside the large cookware can be uniformly cooked in the flexible modes. In another embodiment, in the flexible modes, it is avoided that all of the corresponding driving units are simultaneously turned ON. Thereby, the food products inside the large cookware can be prevented from experiencing instantaneously high temperatures in the flexible modes.
In alternative embodiments, the top surface is divided into two or three separate flexible zones which are elongated in the forward/rearward direction. Each flexible zone has an array of subzones which are elongated in the left/right direction. Thereby, the user can more flexibly use the top surface.
In other alternative embodiments, the induction coils have shapes which match the subzones. In these alternative embodiments, the induction coils may be identical with each other, or at least some of the induction coils may be different.
In other alternative embodiments, the driving units have quasi-resonant inverters and/or resonant half-bridge inverters which can drive the induction coils at power levels down to a few hundred Watts. Also other type of inverters known to those skilled in the art can be used.
Additional advantages of the induction cooking appliance according to the present invention will become more apparent with the detailed description of the embodiments with reference to the accompanying drawings in which:
Figure 1 – is a schematic view of an induction cooking appliance according to an embodiment of the present invention, wherein the dashed lines show the zones and the subzones and the hatched areas show various cookwares.
The reference signs appearing on the drawings relate to the following technical features.

Induction cooking appliance
Top surface
Left flexible zone
Mid flexible zone
Right flexible zone
Large cookware
Large cookware
Large cookware
Subzone
Small cookware
Induction coil
Control unit

The induction cooking appliance (1) of the present invention comprises a top surface (2) which has one or more than one flexible zone (3, 4, 5) each for inductively heating a comparatively large cookware (6, 7, 8), wherein each flexible zone (3, 4, 5) comprises two or more than two side-by-side subzones (9) each for inductively heating a comparatively small cookware (10), induction coils (11) which are arranged under the subzones (9) respectively, driving units each for separately driving a corresponding induction coil (11) respectively at a power level within a power range defined by a lowest power level and a highest power level and a control unit (12) which has a plurality of flexible modes. In the induction cooking appliance (1) of the present invention, the control unit (12) is adapted in the flexible modes to allow a user to select two or more than two side-by-side subzones (9) in the same flexible zone (3, 4, 5) and a common power level which can be smaller than said lowest power level or within said power range or larger than said highest power level and to turn each of the driving units which correspond to the selected side-by-side subzones (9) ON or OFF in accordance with a respective routine in which each corresponding induction coil (11) is driven at a respective power level within said power range such that the average power for the selected side-by-side subzones (9) over a predetermined period equals to the respectively selected common power level (Fig.1).
In an embodiment, the flexible modes include a flexible mode for gentle cooking. The control unit (12) is adapted in the flexible mode for gentle cooking to turn each of the driving units which correspond to the selected side-by-side subzones (9) ON or OFF in accordance with the respective routine in which each corresponding induction coil (11) is driven at a respective power level as close as possible to the lowest power level such that the average power for the selected side-by-side subzones (9) over the predetermined period equals to the respectively selected common power level.
In another embodiment, the control unit (12) is further adapted to execute the flexible mode for gentle cooking when the user selects two or more than two side-by-side subzones (9) in the same flexible zone (3, 4, 5) and a common power level which is smaller than said lowest power level.
In another embodiment, the control unit (12) is adapted in the flexible modes to turn the driving units which correspond to the selected side-by-side subzones (9) sequentially ON or OFF.
In another alternative embodiment, the control unit (12) is further adapted in the flexible modes to avoid turning all of the driving units which correspond to the selected side-by-side subzones (9) simultaneously ON.
In another alternative embodiment, the control unit (12) is further adapted in the flexible modes, where the user has selected three side-by-side subzones (9) in the same flexible zone (4), to turn each of the corresponding three driving units ON or OFF in accordance with a respective routine in which the predetermined period comprises a time interval during which the driving units corresponding to the mutually furthest selected subzones (9) are turned ON and the driving unit corresponding to the intermediate selected subzone (9) is turned OFF and another time interval during which the driving units corresponding to the mutually furthest selected subzones (9) are turned OFF and the driving unit corresponding to the intermediate selected subzone (9) is turned ON.
In another alternative embodiment, the control unit (12) is further adapted in the flexible modes where the user has selected three side-by-side subzones (9) in the same flexible zone (4), to turn each of the corresponding three driving units ON or OFF in accordance with a respective routine in which said predetermined period comprises a time interval during which the driving units corresponding to the selected two rear side-by-side subzones (9) are turned ON and the driving unit corresponding to the selected front subzone (9) is turned OFF and another interval during which the driving units corresponding to the selected two front side-by-side subzones (9) are turned ON and the driving unit corresponding to the selected rear subzone (9) is turned OFF.
In another embodiment, the top surface (2) has two separate side-by-side rectangular flexible zones (3, 5) each elongated in the forward/rearward direction, wherein the left flexible zone (3) has an array of four side-by-side rectangular subzones (9), wherein the right flexible zone (5) has an array of four side-by-side rectangular subzones (9) and wherein the side-by-side rectangular subzones (9) are elongated in the left/right direction and each has an equal size.
In another embodiment, the top surface (2) has three separate side-by-side rectangular flexible zones (3, 4, 5) each elongated in the forward/rearward direction, wherein the left flexible zone (3) has an array of four side-by-side rectangular subzones (9), wherein the mid flexible zone (4) has an array of three side-by-side rectangular subzones (9), wherein the right flexible zone (5) has an array of four side-by-side rectangular subzones (9) and wherein the side-by-side rectangular subzones (9) are elongated in the left/right direction and each has an equal size.
In another embodiment, the induction coils (11) are identical and oval shaped so as to match the subzones (9) respectively.
In another embodiment, the driving units comprise quasi-resonant inverters, wherein the lowest power level is in the range of 700 Watts to 800 Watts.
In another alternative embodiment, the driving units comprise resonant half-bridge inverters, wherein the lowest power level is about 500 Watts.
In another embodiment, the control unit (12) further comprises a plurality of single modes. The control unit (12) is adapted in the single modes to allow a user to singly select a subzone (9) in any flexible zone (3, 4, 5) and a common power level which can be smaller than said lowest power level or within said power range and to turn the driving unit which correspond to the singly selected subzone (9) ON or OFF in accordance with a respective routine in which the corresponding induction coil (11) is driven at a respective power level within said power range such that the average power for the singly selected subzone (9) over a predetermined period equals to the respectively selected common power level.
In another embodiment, the single modes include a single mode for gentle cooking. The control unit (12) is adapted in the single mode for gentle cooking to turn the driving unit which corresponds to the singly selected subzone (9) ON or OFF in accordance with a respective routine in which the corresponding induction coil (11) is driven at a respective power level as close as possible to the lowest power level such that the average power for the singly selected subzone (9) over the predetermined period equals to the respectively selected common power level.
In another embodiment, the control unit (12) is further adapted to execute the single mode for gentle cooking when the user singly selects a subzone (9) in any flexible zone (3, 4, 5) and a common power level which is smaller than said lowest power level.

Claims

An induction cooking appliance (1) comprising a top surface (2) which has one or more than one flexible zone (3, 4, 5) each for inductively heating a comparatively large cookware (6, 7, 8), wherein each flexible zone (3, 4, 5) comprising two or more than two side-by-side subzones (9) each for inductively heating a comparatively small cookware (10), induction coils (11) which are arranged under the subzones (9) respectively, driving units each for separately driving a corresponding induction coil (11) at a power level within a power range defined by a lowest power level and a highest power level, characterized in that a control unit (12) which has a plurality of flexible modes, wherein the control unit (12) is adapted in the flexible modes to allow a user to select two or more than two side-by-side subzones (9) in the same flexible zone (3, 4, 5) and a common power level which can be smaller than said lowest power level or within said power range or larger than said highest power level and to turn each of the driving units which correspond to the selected side-by-side subzones (9) ON or OFF in accordance with a respective routine in which each corresponding induction coil (11) is driven at a respective power level within said power range such that the average power for the selected side-by-side subzones (9) over a predetermined period equals to the respectively selected common power level.
The induction cooking appliance (1) according to claim 1, characterized in that the flexible modes includes a flexible mode for gentle cooking, wherein the control unit (12) is adapted in the flexible mode for gentle cooking to turn each of the driving units which correspond to the selected side-by-side subzones (9) ON or OFF in accordance with the respective routine in which each corresponding induction coil (11) is driven at a respective power level close to the lowest power level such that the average power for the selected side-by-side subzones (9) over the predetermined period equals to the respectively selected common power level.
The induction cooking appliance (1) according to claim 2, characterized in that

the control unit (12) is further adapted to execute the flexible mode for gentle cooking when the user selects two or more than two side-by-side subzones (9) in the same flexible zone (3, 4, 5) and a common power level which is smaller than said lowest power level.
The induction cooking appliance (1) according to any one of claims 1 to 3, characterized in that the control unit (12) is adapted in the flexible modes to turn the driving units which correspond to the selected side-by-side subzones (9) sequentially ON or OFF.
The induction cooking appliance (1) according to any one of claims 1 to 3, characterized in that the control unit (12) is further adapted in the flexible modes to avoid turning all of the driving units which correspond to the selected side-by-side subzones (9) simultaneously ON.
The induction cooking appliance (1) according to claim 5, characterized in that the control unit (12) is further adapted in the flexible modes, where the user has selected three side-by-side subzones (9) in the same flexible zone (3, 4, 5), to turn each of the driving units which correspond to the selected three side-by-side subzones (9) ON or OFF in accordance with a respective routine in which the predetermined period comprises a time interval during which the driving units corresponding to the mutually furthest selected subzones (9) are turned ON and the driving unit corresponding to the intermediate selected subzone (9) is turned OFF and another time interval during which the driving units corresponding to the mutually furthest selected subzones (9) are turned OFF and the driving unit corresponding to the intermediate selected subzone (9) is turned ON.
The induction cooking appliance (1) according to claim 5, characterized in that the control unit (12) is further adapted in the flexible modes where the user has selected three side-by-side subzones (9) in the same flexible zone (3, 4, 5), to turn each of the driving units which correspond to the selected three side-by-side subzones (9) ON or OFF in accordance with a respective routine in which said predetermined period comprising a time interval during which the driving units corresponding to the selected two rear side-by-side subzones (9) are turned ON and the driving unit corresponding to the selected front subzone (9) is turned OFF and another interval during which the driving units corresponding to the selected two front side-by-side subzones (9) are turned ON and the driving unit corresponding to the selected rear subzone (9) is turned OFF.
The induction cooking appliance according to any one of claims 1 to 7, characterized in that the top surface (2) has two separate side-by-side rectangular flexible zones (3, 5) each elongated in the forward/rearward direction, wherein the left flexible zone (3) has an array of four side-by-side rectangular subzones (9), wherein the right flexible zone (5) has an array of four side-by-side rectangular subzones (9) and wherein the side-by-side rectangular subzones (9) are elongated in the left/right direction and each has an equal size.
The induction cooking appliance according to any one of claims 1 to 7, characterized in that the top surface (2) has three separate side-by-side rectangular flexible zones (3, 4, 5) each elongated in the forward/rearward direction, wherein the left flexible zone (3) has an array of four side-by-side rectangular subzones (9), wherein the mid flexible zone (4) has an array of three side-by-side rectangular subzones (9), wherein the right flexible zone (5) has an array of four side-by-side rectangular subzones (9) and wherein the side-by-side rectangular subzones (9) are elongated in the left/right direction and each has an equal size.
The induction cooking appliance (1) according to claim 9, characterized in that said induction coils (11) are identical and oval shaped so as to match the subzones (9).
The induction cooking appliance (1) according to claim 10, characterized in that said driving units comprising quasi-resonant inverters, wherein said lowest power level is in the range of 700 Watts to 800 Watts.
The induction cooking appliance according (1) to claim 10, characterized in that said driving units comprising resonant half-bridge inverters, wherein said lowest power level is about 500 Watts.
The induction cooking appliance according (1) to claim 12, characterized in that the control unit (12) further comprising a plurality of single modes, wherein the control unit (12) is adapted in the single modes to allow a user to singly select a single subzone (9) in a flexible zone (3, 4, 5) and a common power level which can be smaller than said lowest power level or within said power range and to turn the driving unit which correspond to the singly selected subzone (9) ON or OFF in accordance with a respective routine in which the corresponding induction coil (11) is driven at a respective power level within said power range such that the average power for the singly selected subzone (9) over a predetermined period equals to the respectively selected common power level.