EP2943044A1 - Heater for a cooking appliance and cooking appliance, in particular a hotplate - Google Patents

Abstract

The invention relates to a heating element (8) for a cooking device (1), comprising a strip - shaped heating conductor (16) having a first end (16a) and a second end (16b), the heating conductor (16) having a first heating conductor section (18 ), which has a first heating power per unit area, and has at least one second heating conductor section (19) adjoining the first heating conductor section (18) and having a second heating power different from the first heating power per unit area. The invention also relates to a cooking appliance (1).

Description

The invention relates to a heating element for a cooking appliance, comprising a band-shaped heating conductor, which has an electrical connection at a first end and a second electrical connection at a second end. Furthermore, the invention relates to a cooking appliance, in particular a hob, with at least one such radiator.

From the DE 32 06 024 A1 is an electric hotplate known. In order to intensify a warm-up process there is a higher heat output. This increased heating power is to be achieved in that a radiant heater has two heating coils, wherein a heating coil largely covers, with the exception of the outermost peripheral region, the cooking zone area and is designed in the form of semicircular heating areas with mutually concentric winding layers. This heating coil is surrounded by a circular additional single-stranded heating coil, which is located directly on the periphery of the hob. The two separate heating coils are each designed as separate heat conductors, their respective two ends being formed with electrical connection points. In this known radiator, the conceptual design to improve the cooking time or to improve the Ankochvorgangs is relatively expensive, and it will require several different separate heating conductors.

It is an object of the present invention to provide a radiator and a cooking appliance with such a radiator, which or which is improved with respect to the conceptual design to achieve different heating performance.

This object is achieved by a radiator and a cooking appliance according to the independent claims.

A heating element according to the invention for a cooking appliance comprises a strip-shaped heating conductor which has an electrical connection at a first end and a second electrical connection at a second end. An essential idea of the invention is to be seen in that the heating conductor along its band-shaped configuration has a first Heizleiterabschnitt having a first heating power per unit area and thus a Heizleistungsdichte, and along its band-shaped configuration at least one adjoining the first Heizleiterabschnitt and second connected thereto Has Heizleiterabschnitt, which has a different first heating power per unit area second heating power per unit area of the same size. Such a configuration thus virtually provides a single heating conductor, which is designed as a strip or strand, which along its length comprises at least two different heating conductor sections which have different electrical heating powers per unit area of the same size. As a result of this refinement, an individual section design is thus integrated, so to speak, integrated in a single heating conductor, which has only two ends in its linear or single-track configuration, which makes it possible to provide different heating powers per unit area in the single heating conductor itself. By such a configuration, a radiator is created, which is formed on the one hand reduced component, on the other hand, a more flexible and variable possibility of different heating power provision allows. By such a configuration, an improvement of the Ankochvorgangs is also associated.

The unit area is preferably one square centimeter.

It is preferably provided that the first heating conductor section has a meander-shaped turn, which has ring-like winding sections. These annular winding sections preferably have a circumferential length greater than 270 °, preferably greater than 300 °. These ring-like winding sections thus also represent horseshoe-shaped winding sections.

These winding sections preferably run concentrically around a radiator axis.

Such a configuration on the one hand achieves the most uniform and thus homogeneous distribution of the turn sections. On the other hand, a densely packed arrangement of these turns sections is thus possible. Especially in this embodiment with a single band-shaped heating conductor having different heating powers per unit area at different Heizleiterabschnitten, then the above-mentioned advantages are given in particular.

It is preferably provided that the second heating conductor section has a meandering turn. Again, the above-mentioned for the first Heizleiterabschnitt advantageous embodiments with respect to the shape and / or orientation are to be regarded as advantageous embodiments, and thus then here also the advantages mentioned above go along.

It is preferably provided that the first heating conductor section is arranged radially further out than the second heating conductor section, in particular when the heating conductor sections are designed as ring-like windings. By this local specification of the respective Heizleiterabschnitte a locally very defined heating power provision can be made possible and transferred to a cookware or a preparation vessel.

Advantageously, the first heating power per unit area is higher than the second heating power per corresponding unit area. As a result, a greater heating power per unit area is virtually provided at the outer regions than in the inner region. This is particularly advantageous for a very fast and targeted warming up. Since usually a bottom of a cookware usually has a concave shape and the bearing surface concentrates on the outer surface, such a design also results in better heat transfer from the radiator to the bottom of the cookware. This heat transfer by heat radiation and heat conduction is particularly favored by this advantageous embodiment of the invention in terms of improved heat transfer.

Due to the small air gap in the middle of the heating system consisting of the radiator, a cooking plate and the cookware is reduced there

Heat transport predominantly on the heat radiation. This air gap thus arises in particular between the above-mentioned curved bottom of the cookware and a plate, in particular a hob plate on which the cookware is placed and under which the radiator is located.

A portion of this radiation is then reflected back from the bottom of the cookware to this plate and to the radiator, whereby the temperature inside increases disproportionately to the outer heated surface.

In an advantageous embodiment, it is provided that the heating conductor has a third heat conductor section, which has a first and second different third heating power per unit area. By virtue of such a specification, the flexibility and individuality with respect to an improved heating power distribution per unit area can be made even more finely adjusted and more detailed. The above advantages are thereby achieved again in an improved manner.

It is preferably provided that the third heat conductor section has a meandering turn and, viewed in the radial direction, is arranged at least in regions between the first and the second heat conductor section. Again, with respect to the preferably ring-like configuration of the winding with its Windungsabschnitten apply the above already mentioned to the first and the second Heizleiterabschnitt advantageous embodiments, which then leads here to the advantages already mentioned there.

It is preferably provided that the first Heizleiterabschnitt viewed in the radial direction of the windings of the heating element is at least partially arranged as the radially outermost Heizleiterabschnitt and the inside of the third Heizleiterabschnitt is arranged. Again, looking inward in the radial direction, the first heating conductor section is again arranged, and then, in turn, the second heating conductor section is arranged inwards. The winding arrangement of the heating conductor sections is thus arranged so that this interleaving results in the radial direction. This particular specification of the arrangement of the Heizleiterabschnitte viewed in the radial direction allows a very specific distribution of heating power, a particularly efficient introduction of heating power per Area unit in a bottom of a cookware, even if this cookware has a relatively large bottom surface.

It is preferably provided that the third heating power is greater than the first and the second heating power. Considered in the radial direction of the arrangement and design of the heating is thus initially seen from the outside a quasi-average heating power per unit area and then increases inward in the radial direction, the heating power to the highest heating power value, in turn then radially further inwardly going on to be reduced the average Heizleistungswert, in turn then radially further inward migrating to the smallest Heizleistungswert fall.

Also by such a specific embodiment, the above-mentioned advantages in terms of a return reflection of a portion of the radiation from the bottom of the cookware to the hob plate and radiator allows, which then increases the temperature in the radially inner region disproportionately to the outer heated surface.

Furthermore, by this specific embodiment and incidentally also by the invention generally a local overheating of the cooktop panel in the radially inner region of the cooking zone, which is defined by the dimensions of the radiator can be avoided.

By this specific layout of the heat conductor according to the invention and this avoiding overheating of the cooktop panel in the radially inner region is also up to the response of a temperature limiter of a protective circuit more energy in the entire cooking system, which includes the radiator and the cookware, in particular also the cooktop panel , transfer. This additionally reduces the cooking time.

Preferably, it is provided that the heating conductor sections are formed as separate bands, which are connected at connecting points to a single strand as a heating conductor, so that the strand is designed with a single track or single line. Thus, they can first be produced as separate tapes, which in this regard a high Individuality is achieved. This applies in particular to form-specific individuality and material-specific individuality.

By then these separate bands are connected to form a single strand or a single continuous band, then in turn results in a one-piece heating element, so that the strand is designed in one lane or in one line.

In an advantageous embodiment, it is provided that the heating conductor is formed as a one-piece, connectionless strand and in the context is virtually not composed of separate pieces, but is made as a part. By such a configuration of the assembly effort for connecting individual bands is avoided.

Preferably, it is provided that the heating conductor sections are different in their heights and / or widths and / or material compositions and thus the different heating powers are formed or defined. In this connection, a wide variety of shapes and specifications relating to height differences and / or width differences can be formed. With regard to the height, symmetrical or asymmetrical height changes can be formed relative to a longitudinal axis of the band-shaped heating conductor. It can also be provided that shaping of a heating conductor section from this longitudinal axis in the vertical direction, viewed upwards, forms a different shape than viewed in a downward direction in the vertical direction relative to this longitudinal axis. As a result, a wide variety of heating conductor sections can be configured in a variety of configurations, so that individual account can also be taken with regard to their respective lengths and / or space requirements.

It is preferably provided that the radiator has a temperature limiter unit, which is connected in particular in series with the heating conductor. In particular, it is provided that the temperature limiting unit has a sensing element and thus in particular a temperature sensing element and has a mechanically translated switching contact, which is connected in series with the heating conductor. This temperature limiter unit is preferably arranged between the heating conductor and the hob plate already mentioned above. As soon as a given or set limit temperature value is reached as the threshold value, the heating power supply is switched off or at least reduced by this temperature limiter unit.

Furthermore, the invention relates to a cooking appliance, in particular a hob, with at least one radiator according to the invention or an advantageous embodiment thereof.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and feature combinations mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination but also in other combinations or in isolation, without the frame to leave the invention. Thus, embodiments of the invention are to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, however, emerge and can be produced by separated combinations of features from the embodiments explained.

Fig. 1

eine schematische perspektivische Darstellung eines Ausführungsbeispiels eines erfindungsgemäßen Gargeräts;

Fig. 2

eine Draufsicht auf ein erstes Ausführungsbeispiel eines erfindungsgemäßen Heizkörpers;

Fig. 3

eine Draufsicht auf ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Heizkörpers;

Fig. 4

eine Draufsicht auf ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Heizkörpers;

Fig. 5

eine Seitenansicht auf ein Ausführungsbeispiel eines Heizleiters eines erfindungsgemäßen Heizkörpers; und

Fig. 6

eine Seitenansicht auf ein weiteres Ausführungsbeispiel eines Heizleiters eines erfindungsgemäßen Heizkörpers.

Embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

Fig. 1

a schematic perspective view of an embodiment of a cooking appliance according to the invention;

Fig. 2

a plan view of a first embodiment of a radiator according to the invention;

Fig. 3

a plan view of another embodiment of a radiator according to the invention;

Fig. 4

a plan view of another embodiment of a radiator according to the invention;

Fig. 5

a side view of an embodiment of a heat conductor of a radiator according to the invention; and

Fig. 6

a side view of a further embodiment of a heat conductor of a radiator according to the invention.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

In Fig. 1 a cooking appliance 1 is shown, which is a hob in the embodiment. The cooking appliance 1 comprises a hob plate 2, which may be formed of glass or glass ceramic. On an upper side 3 of the hob plate 2 are in the embodiment in terms of number, position and shape only to be understood by way of example cooking zones 4, 5, 6 and 7 formed. These can be seen on the top 3, marked by appropriate marks these cooking zones 4 to 7. The cooking appliance 1 further comprises at least one radiator 8, 9, 10 and 11 arranged below the hob plate 2. These radiators 8 to 11 are arranged positionally below the hob plate 2 in such a way that the surface areas of the identified cooking zones 4 to 7 are heated.

The radiators 8 to 11 are designed as radiant heaters and are operated by a control and / or regulating unit, not shown.

The cooking appliance 1 also includes an operating device 12, which is also to be understood as an example only with regard to their positional arrangement and design. The operating device 12 comprises by way of example at least one operating element and a display unit, wherein the operating element can be a manually operated and relative to the hob plate 2 movable operating element or can be a touch-sensitive control element.

In Fig. 2 an embodiment of a radiator is shown in a plan view, wherein the radiator 8 is shown here by way of example. This radiator 8 comprises a cup-shaped base body 13, which circumferentially has an insulation ring 14. This insulating ring 14 is arranged on a pot bottom 15.

In addition, the heating element 8 comprises a band-shaped heating conductor 16. This band-shaped heating conductor is formed as a single strand or as a single band and comprises only two ends, a first end 16a and a second end 16b. In particular, these ends 16a and 16b also each have an electrical connection 17a and 17b. This band-shaped heating conductor 16 is, as in Fig. 2 can be seen in the plan view, multiple wound, here meander-shaped turns are designed, which are arranged circumferentially around a center A of the radiator 8 ring-like. They are laid horseshoe-like. It is provided in the embodiment shown that this single heating element 16 has a first heating conductor section 18 and a second heating conductor section 19. These two heating conductor sections 18 and 19 are connected to one another at a connection point 20. Thus, the first Heizleiterabschnitt 18 opens with its first end, which is the end 16a of the entire heat conductor 16 in the embodiment, to the outside, and opens with a second end opposite this end 16a to the connection point 20. Accordingly, the second Heizleiterabschnitt 19 is formed in that it opens at a first end to the connection point 20 and to the outside with a second end, which in the exemplary embodiment represents the second end 16b of the entire heating conductor 16.

As in the illustration in Fig. 2 can also be seen, the first Heizleiterabschnitt 18 a plurality of these ring-like windings, viewed in the radial direction represent the more outer turns. In contrast, therefore, are also more numerous turns of the second Heizleiterabschnitts 19 viewed in the radial direction further inside.

The radiator 8 further comprises a temperature limiter unit 21, which has a temperature sensor or a sensor element 22 and a mechanically translated switching contact 23. This switching contact 23 is connected in series with the heating conductor 16.

In the exemplary embodiment, the heating conductor sections 18 and 19 have different electrical heating powers per respective same unit area, wherein the first Heating power per unit area of the first Heizleiterabschnitts 18 is greater than the second heating power per unit area of the second Heizleiterabschnitts 19th

In Fig. 3 a further embodiment of a radiator 8 is shown in a simplified plan view.

In contrast to the embodiment according to Fig. 2 It is provided here that the heating conductor 16 has a third heating conductor section 24 in addition to the first heating conductor section 18 and the second heating conductor section 19. This third heating conductor section 24 has a third heating power per unit area, which is different from the first heating power per unit area and the second heating capacity per unit area. In particular, this third heating power per unit area is greater than the first heating power per unit area and the second heating capacity per unit area. Here too, a connection point 20 is then formed between the first heat conductor section 18 and the second heat conductor section 19. In addition, a further connection point 25 is formed between the second heat conductor section 19 and the third heat conductor section 24. In this embodiment according to Fig. 3 it is then provided that one of the only two ends 16a and 16b, namely the second end 16b, also represents the end of the third heat conductor section 24. The first end 16a of only two ends of the entire heating conductor 16 is again formed by one end of the first heating conductor section 18.

With regard to the winding configuration of the heating conductor 16 in FIG Fig. 3 starting from the first end 16a, this starts with the first heating conductor section 18, which thus also initially starts circumferentially around the center A with a radially outermost turn. Following inward in the radial direction then preferably includes a plurality of winding sections of the third heating conductor section 24. Again following radially inward, a further turn section of the first heating conductor section 18 is then arranged, wherein in turn, following this, in the radial direction following inwards, a plurality of turn sections of the second heating conductor section 19 follow. These then also close off the entire turn sections towards the center A.

In the versions in Fig. 2 and Fig. 3 the entire single-stranded or single-band heating conductor 16 is composed of a plurality of sections arranged in series one behind the other composed, which form through the Heizleiterabschnitte 18 and 19 and additionally 24. It is thus here a one-piece heating element 16 is formed, which have only two ends 16a and 16b in its overall design.

In the illustration according to Fig. 4 is a further embodiment of a radiator 8 shown in a plan view. In contrast to the embodiment according to Fig. 3 Here, the three Heizleiterabschnitte 18, 19 and 24 are not provided as separate bands, which are connected via connecting points 20 and 25 to a one-piece strand, but this heating element 16 is manufactured and provided by default as a one-piece component. Connecting points 20 and 25, at which the separate bands are thus connected to one another according to their own respective production and production in an explicit connection step, is not formed here.

The different heating power per unit area of Heizleiterabschnitte 18 and 19 and in the embodiment according to Fig. 3 and Fig. 4 can be due to different heights (in the direction perpendicular to the plane of the figure in Fig. 2 to Fig. 4 ) and / or different widths and / or different material compositions.

With respect to the radial arrangement of the winding sections of the meandering turns of the heating conductor sections 18, 19 and 24 in FIG Fig. 4 is on the arrangement, as in Fig. 3 referred to. In principle, however, other radial arrangements of the winding sections of the individual heating conductor sections 18, 19 and 24 may be provided.

In the Fig. 2 to 4 the respective Heizleiterabschnitte are symbolized by the different dashed lines, so that in particular the respective preferred course and the arrangement are illustrated to each other.

In Fig. 5 is an example of an embodiment of a heat conductor 16 shown in a side view. It can be seen that the heating conductor section 24 forms a greater height, which is measured perpendicular to a longitudinal axis B of the heating conductor 16. The longitudinal axis B is measured between the ends 16a and 16b, and the height is measured perpendicular thereto, so that they are in the representations in Fig. 2 to Fig. 4 perpendicular to Figure axis measured. As in the illustration according to Fig. 5 can be seen, the third Heizleiterabschnitt 24 viewed from the longitudinal axis B upwards and thus the pot bottom 15 facing away from a trapezoidal elevation 24a. On the opposite side and thus facing the bottom of the pot 15, a plurality of tongues 24b are formed, of which only a few are provided with the corresponding reference numerals for clarity.

In contrast, the first heat conductor section 18 has a lower height than the third heat conductor section 24. He has no such trapezoidal elevation 24a in the embodiment. Only at its lower edge and thus to the pot bottom 15 in turn corresponding tabs or tongues 18a are formed.

The second heat conductor section 19 is formed in the embodiment with respect to its basic geometric shape design corresponding to the first heat conductor section 18. However, here the height of a median strip 19b is smaller compared to a median strip 18b. Otherwise, here also downwards and thus in the direction of the pot bottom 15 tabs or tongues 19a are formed.

In Fig. 6 is another embodiment of a heat conductor 16 is formed, in which case symmetrical shapes are designed to the longitudinal axis B. This means that the third heat conductor section 24 has trapezoidal elevations 24a and 24c, which are designed to be equally large, both upwardly and downwardly. In contrast, even in the first heat conductor section 18, only the center strip 18b is present and the tabs 18a are not formed. The height of this central strip 18b is smaller than the entire height of the trapezoidal elevations 24a and 24c. On the other hand, in turn, only the center strip 19b is formed in the second heat conductor section 19 and no corresponding tongues 19a are present. The height of this median strip 19b is smaller than the height of the median strip 18b. Due to the respective specific shapes of the heating conductor sections 18, 19 and 24, different electrical resistances are also formed, which then also result in the different heating powers per unit area.

LIST OF REFERENCE NUMBERS

1

Cooking appliance

2

Hotplate

3

top

4, 5, 6, 7

cooking zones

8, 9, 10, 11

radiator

12

operating device

13

body

14

insulation ring

15

pot base

16

heating conductor

16a

first end

16b

second end

17a, 17b

electrical connections

18

first heating conductor section

18a

tongues

18b

central reservation

19

second heating conductor section

19a

tongues

19b

central reservation

20

junction

21

Temperature limiter unit

22

sensing element

23

switching contact

24

third heating conductor section

24a

survey

24b

tongues

24c

survey

25

junction

A

Focus

B

longitudinal axis

Claims (15)

Radiator (8) for a cooking device (1), comprising a band-shaped heating conductor (16) having a first end (16a) and a second end (16b), characterized in that the heating conductor (16) has a first heating conductor section (18) which has a first heating power per unit area, and has at least one second heat conductor section (19) adjoining the first heating conductor section (18) and having a second heating power different from the first heating power per unit area. Radiator (8) according to claim 1, characterized in that the first heating conductor section (18) has a meandering turn. Radiator (8) according to claim 1 or 2, characterized in that the second heating conductor section (19) has a meandering turn. Radiator (8) according to claim 2 and 3, characterized in that the first Heizleiterabschnitt (18) is arranged radially further outward than the second Heizleiterabschnitt (19). Radiator (8) according to one of the preceding claims, characterized in that the first heating power per unit area is higher than the second heating power per unit area. Radiator (8) according to one of the preceding claims, characterized in that the heating conductor (16) has a third heating conductor section (24) which has a first and second different third heating power per unit area. Radiator (8) according to claim 6, characterized in that the third Heizleiterabschnitt (24) has a meandering turn and at least partially disposed in the radial direction of the turns of the heating conductor (16) between the first (18) and the second Heizleiterabschnitt (19) is. Radiator (8) according to claim 6 or 7, characterized in that the first Heizleiterabschnitt (18) in the radial direction of the turns of the heating conductor (16) viewed at least in sections as the radially outermost Heizleiterabschnitt is arranged and inwardly following the third Heizleiterabschnitt (24) is again and in turn following the first Heizleiterabschnitt (18) is arranged and in turn following the second Heizleiterabschnitt (19) is arranged inwardly following. Radiator (8) according to one of claims 6 to 8, characterized in that the third heating power per unit area is greater than the first and the second heating power per unit area. Radiator (8) according to one of the preceding claims, characterized in that the heating conductor sections (18, 19, 24) are separate bands which are connected at connection points (20, 25) to form a single strand as a heating conductor (16). Radiator (8) according to one of the preceding claims 1 to 9, characterized in that the heating conductor (16) is formed as a one-piece strand. Radiator (8) according to one of the preceding claims, characterized in that the heating conductor sections (18, 19, 24) in their perpendicular to a longitudinal axis (B) of the heating conductor (16) sized heights and / or widths and / or material compositions are different and thereby the different heating powers per unit area are defined. Radiator (8) according to one of the preceding claims, characterized in that a temperature limiter unit (21) is formed which is connected in series with the heating conductor (16). Radiator (8) according to claim 13, characterized in that the temperature limiter unit (21) has a sensor element (22) and a mechanically translated switching contact (23) which is connected in series with the heating conductor (16). Cooking appliance (1), in particular hob, with at least one heating element (8) according to one of the preceding claims.

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