EP0757508B1 - Cooking hob with a plurality of cooking zones disposed underneath a plate - Google Patents

Abstract

The hob has several cooking points (12) contg. heating elements in a heating zone (13,13a) and thermal insulation, esp. radiation cooking points, arranged inside a trough (14) of flat material, esp. sheet metal. The thermal insulation for each cooking point is separately mounted directly on the trough. The unit (11) forms a prefabricated, connectable component with an integrated control, regulation, monitoring and connection system which contains all the control, regulation, monitoring and connection devices as far as the mains system and any adjustment and input devices.

Description

APPLICATION AREA AND PRIOR ART

The invention relates to a hob unit with several below a plate, in particular a glass ceramic plate, arranged, arranged in at least one heating zone Heating elements and hotplates containing thermal insulation, in particular radiant hotplates and a method for their Production.

Usual hob units of this type consist of one Metal trough on the underside of a glass ceramic plate is arranged or carries it itself. There are individuals in it Radiation hotplates arranged, which are themselves a sheet metal tray have in which on thermal insulation material Heating elements are attached, see e.g. US-A-3 870 862. Each individual radiant heater is by resilient bracket parts acting on the carrier shell pressed onto the underside of the glass ceramic plate (see DE 27 60 339 C2 and DE 36 13 902 A1).

It has also become known to use radiant heaters create multiple heating zones within a hob have, which can be switched on or off to the Change the shape and size of the hotplate (see DE 29 43 477 C2). From DE 27 60 339 C2 is also known on the to arrange rings lying on a support plate, the several heating fields with heating conductors one Delimit multiple unit cooking appliance. The previous concept with such hob units always assumed that the the radiant heaters that form the cooking zones are individual, in themselves manufactured and functioning units that are compatible with the share of control, monitoring or Provide control units or their sensors and connections are. These units were made independently checked and stored. In a second manufacturing stage these units were then placed in a sheet metal trough and finally with the independent control input or setting devices and the associated mains connections Mistake. This was and is in connection with this description for both independent, in the opening Cooking hobs that can be used on a worktop of a kitchen furniture, as well as for the hobs of a special cooker or stand-alone cooking appliances with several hotplates, all of which are referred to as cooktop units become.

TASK AND SOLUTION

The object of the invention is to provide a hob unit create a simplified manufacturing, assembly and Testing enables, in particular the saving of components enables and with given space conditions enables improved thermal insulation.

This object is achieved by claim 1 and the independent Process claim resolved.

Due to the individual arrangement of the thermal insulation in the trough, preferably in the form of separate molded parts, can use separate sheet metal trays for each hotplate omitted. This enables thermal insulation in particular down to make it thicker so that it covers the entire surface Space available, limited by the installation depth exploits. The thermal insulation can also be independent to the side of any basic form and must be in their shape does not always correspond to the heating zone.

The individual thermal insulation components can directly to Be receptacle belonging to the trough, for example on punched out of the trough and on the corresponding Place optionally bent sheet metal tabs. The desirable Pressing the upper, mostly ring-shaped boundary part the thermal insulation that surrounds the heating zone to the Bottom of the plate can be directly on this Resilient spacers acting on the limiting part happen. The heating element carrier, which is an independent one Component is, remain on the trough floor, so that the thermal insulation behaves practically telescopically and thereby exploiting the height in an ideal manner. It is also possible to form the trough in two parts, namely from a circumferential frame and one contained the floor Part, both by spring means provided on the edge in In the sense of a compression. This allows the Suspension for all hotplates can be made together, with plastically deformable spacers necessary alignment of the individual hotplates for adaptation can be done to the plate.

Due to the possibility of the hob unit immediately and without producing the intermediate stage of the individual radiant heaters, are numerous manufacturing, storage and Assembly steps saved. Most of all, the unit can be together with an integrated control, regulation, monitoring and Connection system a prefabricated, connectable component form. By combining the control functions of the individual hotplates can sometimes be more complex Components are used that are in parallel and serial Information processing control the individual functions, for example pot detection, i.e. the control of the Switching on depending on the placement of a suitable cooking vessel. By assembling all of them it is also the components of the hob unit possible to automate assembly processes that were previously due the problems with the positioning etc. not or only difficult to automate, for example the Wiring and welding the same to the individual Components.

It is also possible to optimize the thermal insulation use by the material of its kind, composition and density and processing exactly according to the Requirements can be chosen. For example, for the strength-critical parts, such as limiting the heating zones where there is a sharp optical separation arrives, a more form-fitting thermal insulation material be used as for the insulation pad, while e.g. in the case of the heating element carriers in addition to the thermal insulation property also particularly on the temperature resistance to watch out for.

If the boundary part is spanned by a ring, can this is an induction coil for a pot detection system form. But it is also suitable for an external, the Boundary part to form the clamp that holds especially if the delimiting part consists of several Ring sectors or sections is composed to one Summarize ring. It can be in a recess of the Boundary part an outer, e.g. flange-like projection of the heating element support to be positively enclosed, so that after the ring is tightened, a hotplate unit is created, which is self-contained without being special Carrier shell needs.

It is also possible without such a multi-part ring to produce a positive determination that the inserted heating element carrier tablet in your Edge area is deformed by a stamp so that it in Indentations on the inside of the limiting part penetrates. The limiting part can be fiber-free, for example consist of vermiculite and possibly also through air chambers or filled with even better thermal insulation material Chambers be designed as a "sandwich construction". The Ring that is mechanically closed, but electrically open can also be the mechanical bracket for others Form components, for example a temperature limiter, which can be fixed to it by means of snap connections. It is also possible to attack this element with an edge To provide brackets that the boundary part and Holding the heating element carrier together and possibly a spring element forms.

These and other features go beyond the claims also from the description and the drawings, wherein the individual features individually or separately several in the form of sub-combinations in one embodiment of the invention and in other fields be and advantageous as well as protective designs can represent, for which protection is claimed here. The division of the application into individual sections as well Inter-headings limit those made under them Statements are not generally applicable.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1

eine perspektivische Ansicht einer Kochstelleneinheit (ohne Glaskeramikplatte)

Fig. 2

einen vertikalen Teilschnitt durch die Einheit,

Fig. 3

eine perspektivische, teilgeschnittene Detailansicht eines Teils der Mulde

Fig. 4

ein Detail der Befestigung eines Temperaturbegrenzers,

Fig. 5

eine schematische Draufsicht auf eine Kochmuldeneinheit

Fig. 6

ein Detail der Befestigung einer Topferkennungsspule im Schnitt

Fig. 7

die Ausführung nach Fig. 6 in Draufsicht,

Fig. 8 und 9

weitere Ausführungsformen der Befestigung einer Induktionsspule für die Topferkennung,

Fig. 10

ein Detail der Verlegung von Anschlußleitungen,

Fig. 11

einen Teilschnitt mit einer zusammengesetzten Ausführung des Begrenzungsteils,

Fig. 12

ein Blockschaltbild eines Steuergerätes,

Fig. 13

eine perspektivische Ansicht einer Kochstellen-Einheit

Fig. 14

einen Teilschnitt durch Fig. 13

Fig. 15 bis 17

Varianten im Teilschnitt

Some embodiments are shown in the drawing and are explained in more detail below. Show it

Fig. 1

a perspective view of a hotplate unit (without glass ceramic plate)

Fig. 2

a partial vertical section through the unit,

Fig. 3

a perspective, partially sectioned detailed view of part of the trough

Fig. 4

a detail of the attachment of a temperature limiter,

Fig. 5

is a schematic plan view of a hob unit

Fig. 6

a detail of the attachment of a pot detection coil in section

Fig. 7

6 in plan view,

8 and 9

further embodiments of the attachment of an induction coil for the pot detection,

Fig. 10

a detail of the laying of connection lines,

Fig. 11

a partial section with a composite version of the boundary part,

Fig. 12

1 shows a block diagram of a control device,

Fig. 13

a perspective view of a hotplate unit

Fig. 14

a partial section through Fig. 13th

15 to 17

Variants in partial section

CONSTRUCTION OF THE COOKER

Figures 1 and 2 show a hob unit 11 with four Cooking zones 12, of which three individual cooking zones are different Size with only one heating zone 13 each while the fourth has two heating zones, one of which is like that of the other hotplates is circular, also individually can be switched on while the adjoining heating zone 13a to form an elongated hotplate, e.g. to Heating an oval oven, can be switched on.

The hotplates 12 are arranged in a trough 14 which an edge 15 with a horizontal, circumferential support shoulder 16 for receiving a plate 17, preferably one Glass ceramic plate. A raised outer edge 18 centers the plate and surrounds the outer edge. The hob usually has a rectangular shape with a corresponding one Arrangement of the hotplates in the square.

The trough 14 consists of a rectangular, relatively flat Tin bowl with side walls 19 and a bottom 20. Im Interior 21 are the hotplates without their own sheet metal tray arranged. They are made from individual thermal insulation components 22 built up individually and immediately, however in mutual interaction, attached to the trough are. One of the thermal insulation components is a disc-shaped one Heating element carrier, which is in a recess 26 of the sheet metal recess is partially recorded and centered. Between the surface 24 of the heating element carrier 23 and the plate 17 a distance that forms the heating chamber 27 of the heating zone 13.

It is surrounded in shape by the other thermal insulation component a limiting part 28 which is annular. It is via an angular, circumferential recess 80 to the Heating element carrier 23 connected to its outer circumference and extends to the plate 17, where it rests resiliently. This suspension is in the embodiment of FIG resilient spacers 81 are produced which are made of the material of the trough bottom 20 punched out and bent sheet metal spring parts are trained. You press on the bottom of the limiting part formed as a ring with an L-shaped cross section 28 and push it up against the plate 17. By overlapping and interlocking with the heating element carrier you can move vertically against it, without a radiation or convection gap in the boiler room 27 create.

They are also on one side of the limiting ring 28 Side holder 82 is provided, which is also made of sheet metal of the trough bottom L-shaped sheet metal tabs can be trained. They grab with their horizontal Legs in recesses 84 in the outer circumference 86 of the annular Limiting part 28 and lay it opposite to the side Movements in Fig. 2 to the left and also in the transverse direction to this firmly. You can use one or two of these side holders be provided relatively close to each other. Is opposite him a side holder 83, which is designed as a Z-shaped sheet metal tab is. Its upper, essentially vertical leg 85 lies parallel to the outer side 86 of the limiting part. In him a hole 87 is provided, which with a corresponding horizontal hole 29 in the limiting part is aligned. An additional, also designed as a sheet metal tab 89 lies in the same circumferential area as the side holder 82 and supports an outer surface 30 of the heater base 23 and grips with a diagonally inward curve also partially in an oblique corner recess.

For assembly, the heating element carrier 23 in FIG inserted so obliquely on the right that it with its outer surface 30 rests on the side holder 89, and then in the in Fig. 2nd shown position lowered so that it is then in the recess 26 is included. After that the ring-shaped Limiting part 28 inserted obliquely in the same way, so that its side holder 82 engages in the recess 84. This is large enough to be able to intervene Ensure inclination. After that, the limiting part by tipping it clockwise into the position shown, it being the heating element carrier partially surrounds. Then a rod-shaped temperature sensor 31 of a temperature limiter 32 through each other aligned holes 87 and 29 inserted. So they form a bolt 90 which the limiting part and thus the Heating element carrier 23 and the temperature controller 32 itself the trough defines, however, the limited vertical mobility of the limiting part. This is hole 29 designed accordingly large in the vertical direction.

With this arrangement, it is the limiting part 28 everyone individual hotplate possible, individually with its top surface to the underside of the plate 17 and to limit the boiler room 27 thermally and optically precisely.

This creates a hob unit that has several delimited against each other by outer edges and down thermally insulated cooking areas in a common hollow contains, without each radiator through a sheet metal tray closed to the outside and held together by this is. Rather, it is determined on the trough floor itself, except for the preferred definition by the Die-cut sheet metal tabs also other fastening options, like screws, put in holes Pins or other anchors are possible. It is also possible the entire trough floor in a certain grid with recesses or holes in the corresponding Side holders can be used optionally. In In this case, a larger body could be used with a unit trough Variety of types of different sizes and different arranged hotplates can be produced.

3 shows an embodiment in which the side walls 19 the trough are divided into two. They consist of an upward directed leg 91 and one adjoining the outer edge 15 downward leg 92, the parallel to the leg 91 around the trough. This edge component 93 formed from the edge 15 and the leg 92 is made from a sheet metal profile, which is then attached to the outer edge 18 a horizontal, slightly bent down outside Support edge 94 forms that on a countertop of a piece of kitchen furniture can rest in the opening Hob unit 11 is inserted. This profile could also be manufactured as a continuous casting profile.

Fig. 3 also shows that the two movable against each other Legs 91, 92 together by a spring wire 95 are connected that they try to reduce the trough height and thereby the contact pressure on the top of the Exercise limiting part 28. For this purpose, the spring wire 95 in outward-facing, hook-shaped retaining tabs inserted, each alternately on the two legs 91, 92 so are provided that the wire is wavy when inserted bends and thereby a corresponding spring force exercises.

In this embodiment, the spacers 81 can be designed in this way be that they are less elastic than plastic deformed. It can then be done through a general Alignment when installing the correct distance be made while the permanent suspension that also because of a certain tendency to deform in the thermal insulation materials is necessary due to the overall suspension is maintained between the plate and the trough.

4 shows an attachment of the temperature limiter 32 directly on the trough floor 20 by means of a on the temperature limiter provided, angled sheet metal connector, which on Trough bottom e.g. be fixed by spot welding can.

13 shows a hotplate 12 with a heating element carrier 23 and a multi-part limiting part 28. Es is ring-shaped overall, but from individual ring segments 28a composed, which are interlocked. At the Outer periphery 86 runs a pot detection sensor 44 forming clamp-shaped ring 97 um, which is open at one point and there are two outward turns 98 has, the ends of which form tab connectors 99. The Ring is made by means of an electrically insulating connecting means, for example a ceramic clip or one Screw 100, clamped together and thus clamps the hotplate unit together.

Corresponding tabs are on the tab terminals 99 plugged the sensor 44 with the corresponding Connect the control unit for an inductive pot detection system.

Openings 58 can also be provided in the ring 97, in the snap or connector 57 are inserted to the Define temperature limiter 32 (see also Fig. 2).

14 shows a partial cross section through the embodiment according to FIG Fig. 13. It can be seen there that the ring segments 28a of the Limiting part 28 in cross section towards the inside have open recess 101, in which a corresponding Ring projection 102 on the outer circumference of the heating element carrier 23 intervenes. Since the ring segments 28 through the tire or Clamp 97 are held together by the Attaching the pot detection coil a coherent Cooking area created.

Fig. 15 shows an embodiment in which the annular Limiting part 28 can be formed in one piece. Here is the cross section of the limiting part 28 L-shaped, the short leg of the L is on top and directed towards the inside is to about the surface 24 of the heating element carrier 23 protrude and secure this upwards. The tire 97 is also here, as in the other versions of the Outer circumference and extends to the upper edge of the boundary part, i.e. to the underside of plate 17.

16 shows an embodiment, also with a tire 97, in which the limiting part 28 is formed in one piece as a ring is. It has a modified L-shape in cross-section, whereby the inwardly protruding L-leg lies at the bottom, so that it is a a lower one provided with a circumferential recess 102 Forms the outer edge of the hob component. In the area this recess 102 are also blind holes 103 in the fastening part 28 brought into the corresponding during assembly Can engage projections on the trough. Also are they are suitable to be used during the automatic insertion process Alignment aids to serve.

The heating element carrier 23 is the inner shape of the limiting part 28 adjusted and accordingly has an upper, on Circumference protruding flange and is slightly smaller at the bottom Diameter executed. In the area of the outer flange 105, the heating element carrier 23 on the inside of the Limiting part 28 attached in that after insertion in several places on the circumference a depressing from above Stamp material of the heating element carrier (28) in the form 106 displaced into the inside of the limiting part 28. As a result, the heating element carrier 23 is on the limiting part 28 by deformation of the thermal insulation material locked. The stamp forms recesses or impressions 107 on the surface 24. This deformation happens preferably in several places on the circumference, can but also be carried out all around. It results in a good hold of both thermal insulation molded parts to one another, also because that the deformed material at the deformation points can be a little more compressed.

The resulting gearing can also, alone or in addition, be made vertically instead of as shown in Fig. 16 horizontal. The recesses could be undercut, i.e. expanding, being educated. Depending on the material properties can also connect the limiting part 28 be deformed.

The explanations according to FIGS. 13 to 16 make one Radiant heating cooktop created without the usual Tin plate gets along. It is also possible due to the Protection of the most stressed parts on reinforcing fibers to waive so that the entire radiant heater can be manufactured fiber-free. The edge can, like will be explained in the following, from a relatively stable Material exist, but with air chambers or with better thermal insulation material than the rest of the material Delimiting part 28 have filled chambers. It would be so for example also possible with the material of the heating element carrier 23 filled shape 106 to make larger and over a substantial portion of the height of that from the limiting portion 28 formed edge to extend so that a Execution similar to Fig. 11 arises. The the pot detection coil forming ring or tire 97 is mechanically closed, however electrically "open". The connection can be galvanic, as described or via an air transformer or different types of transformer, for example with ferrite, happen.

Fig. 17 shows an embodiment in which the rest of the similar 15 as the outer surface 86 of the limiting part 28 is designed so that individual brackets 108 can be recorded, which on the delimiting part 28 fixed and a piece above the floor 109 from the limiting part 28 and heating element carrier 23 and extend them stick together. There may also be a spring section thereon 110 may be provided, which is supported on the bottom 20 of the trough. Such a design is especially for the later Replacement of a hotplate is advantageous in the event of repairs. The clip 108 holds with a nose 111, which is in a groove 112 engages on the outer circumference 86 of the limiting part 28. The The clip can be made from resilient sheet metal.

INSULATION

When choosing the thermal insulation material and its design in addition to temperature resistance and if possible also electrical insulation mainly from each other normally excluding properties, namely good Thermal insulation properties and mechanical strength. Under this requirement is the material of the thermal insulation components 23 selected.

A pyrogenic silica airgel is for the heating element carrier 23 preferred that, with appropriate binders and Opacifiers, for example made of metal oxides, mixed, to a tablet-like shaped body, i.e. one more or less thick disc, adapted to the shape of the heating zone is pressed. To increase the mechanical strength reinforcing agents can also be added, however if possible fibers should be avoided.

In the upper surface 24 facing the boiler room 27 electrical resistance heating elements 25 embedded. she consist of thin wavy ribbons that stand upright with provided on its underside, by the curl spade-shaped feet pressed into the thermal insulation material after the tablet has been compressed. These heating elements due to their large surface area compared to Heating element mass has a very short glow time. You are under the applicant's "HiLight" brand. For details their nature, manufacture and function expressly refer to DE-42 29 373 and DE-42 29 375 taken.

The heating element support 23 has on the other level Surface 24 in the middle of an upward projection 33, on which the temperature sensor 31 of the temperature limiter 32 rests. This sensor protrudes depending on the size of the Heating zone up to the middle or a little further above, so that even with different heating zone diameters uniform temperature sensor length can be selected. Usually it is due to the HiLight press fitting technique possible, a heating element carrier with sufficient thermal insulation quality and mechanical strength, above all, if it can have a greater thickness. A special advantage of the integrated hob concept is that the space which was necessary to accommodate the radiator Arrange the carrier shell in the trough and press it upwards, is now available for thermal insulation so that with the same overall height of the trough, some thermal insulation Can be millimeters thicker. However, if there are special requirements, for example an even lower body height or Like. Require it can still under the heating element support a thermal insulation layer, then usually from even lighter and therefore better thermal insulation material of the same type. Also is a multilayer structure of the heating element carrier tablet possible.

The limiting part 28 consists of mechanically stronger Material that is both more shape-resistant and more abrasion-resistant is. Such materials can, for example, be made from slurries formed by ceramic fibers, felt or paper-like thermal insulation materials. However, it will strived to generally increase fibers in thermal insulation materials avoid. It is therefore preferred to be very stable Material, such as vermiculite, prefers an expanded mica that with good mechanical properties, a good electrical one Insulator with reasonable thermal insulation and temperature resistance properties is. That is from this material Boundary part 28 shaped, which especially with great edge sharpness is possible, so that it is particularly accurate Optical limitation of the heating zone is particularly suitable. in the Basically, the material has a mechanical consistency like Plastic or integral foam with a closed surface.

In places where particularly high temperature resistance and / or insulation is required can be in the limiting part 28 inserts 34 may be provided. Fig. 11 shows one Insert 34 on the side of the heating chamber 27 facing the Limiting part. It prevents heat from migrating to Side. The insert is in the form of a circumferential ring molded into a groove 35 in the limiting part 28. The above and Flanges that remain at the bottom are not so thermally endangered, as they are on the one hand on the plate 17 and on the other rest on the heating element carrier 23. Through these missions one different from the rest of the thermal insulation component Material is created a composite construction method the component the characteristics of both in themselves incompatible properties, mechanical strength / good Thermal insulation properties, gives. This composite construction can also be used in other respects, for example in the the positions surrounding the controller part to be explained later or other, provided from above or from the outside Recesses the boundary part.

CONTROL AND REGULATION

The arrangement of the hotplates shown in Fig. 1 in a common trough makes it possible to control, regulate, Monitoring and connection elements for all hotplates to summarize, while at least regarding the components related to the hotplates themselves, for example the temperature limiter and connecting cables, heat detectors or pan detection systems, assigned to each individual hotplate were.

In Fig. 1 it is shown that the temperature limiter 32 in a central area 36 between the four hotplates lie. It is also possible to use the four temperature limiters if necessary together with hot alarm contacts that are from the same Temperature sensors are acted upon in a common Housing 37, from which the temperature sensor go out in a star shape. The hotplate connections also run from there 38 directly to the heating elements. Of the common housing runs from one indicated in Fig. 1 and 4 Wiring harness 39 to the input or display field 40, the in this case to the top and through the glass ceramic plate has adjusting knobs 41 extending therethrough. Instead of one Wiring harnesses made of strands or solid wires can also be a multi-lane matrix of flat conductors can be used. Indicator lamps 42 for a hot display are in a corresponding manner Arrangement to the hotplates provided at a suitable location. Temperature or power control or regulation organs by the adjustment buttons 41 can be influenced in the area the setting field 40 or within the common Housing 37 may be provided.

The residual heat indicator, usually referred to as a hot indicator ensures that the user is made aware of it is that a hotplate is still dangerous for touch Could have temperature. To operate them normally a second contact in the temperature limiter provided, which is actuated by the sensor of the temperature limiter and switches at, for example, 70 ° C. The hot display but could also with others, for example electrical Resistance sensors work, especially when a common one Control electronics is available. Can do the same but also perform a control that depends on the switching on of the hotplates works time-dependent by addresses the hot display with appropriate safety margins, when the radiator is turned on for a period of time is. It runs for the average cooling time below a dangerous temperature after switching off the Heating element and only then switches the hot display out. It can be provided, for example, that only one brief, e.g. accidental switching on, the hot display not yet take effect.

12 is a central regulating and control circuit in the Block diagram shown. Controller 43 is for four Cooking areas 12 are provided, two of which (top left and bottom right) each have a heating element 25, while the two others (bottom left and top right) two each Have heating elements, e.g. for a hotplate with two heating zones 13, 13a.

The control unit also contains a pan detection electronics. For this purpose, induction coils 44 are located on the hotplates, one for each heating element, with the control unit are connected. These pan detection sensors are with one Multiplexer 45 connected, the serial processing of the Signals enabled. The signals arriving in sequence are in a specially adapted, integrated circuit (ASIC) 46 processed, partly under the control of a Microprocessor 47.

The resulting output signals are transmitted via a driver 48 Circuit breakers 49 supplied as electromechanical Relays are shown, but also as electronic Power components can be formed. In the embodiment 12, the power control takes place outside of the control unit 43 in power control units 50, which the adjustment buttons 41 are operated and as individual or can be combined in a common block 51. These power control devices, also known as energy controllers usually work with impulsive performance release and can work electrothermally or electronically.

However, it is also possible to use this power control in to include the control device 43 and only the setting elements pull it out. It could be any Act input means, for example rotary encoders, such as Potentiometer, or key inputs, preferably touch switches, possibly also through the glass ceramic plate Act. In such a case, the setting field could 40 a keypad can be created, by the Touching the user's choice of individual hotplates and their attitude can bring about.

The microprocessor also controls an appropriate one Control 52 the hot display field 42 in the form of light emitting diodes. In this case, the temperature limiters are wired provided outside the control unit 43, can however, also be largely structurally associated with it.

The control device is provided in the central area 36. With appropriate thermal insulation it is against heat from the Shielded heating zones. As Fig. 2 shows, it can heat Deliver over the floor 20, if necessary also upwards over the Glass ceramic plate, if that is tolerated by the electronics Temperature level is relatively high. Further measures can be taken contribute to cooling here, for example an interruption of the floor 20 around the central area 36, for example through the slots 52 in Fig. 2, through in this Area attached heat sink or even by active Cooling using a Peltier element.

In any case, a common control unit allows, too technically relatively complex functions, such as pot detection, to make usable because of the effort for several hotplates is hardly bigger than for one.

The evaluation of the signals of the pot detection sensors 44 can according to the prior art, for example according to the DE-40 04 129, the content of which is expressly referred to here is taken.

Due to the environmental conditions, especially the high and changing temperature, but is the arrangement of the pot detection sensors, which are designed as induction coils are particularly critical. In Figures 6 to 9 are different Variants shown, each as a single wind Coils are running. FIGS. 6 and 7 show an embodiment, in which the limiting part 28 one from its top outgoing, annular slot 75 in the inserted a single-turn loop as a pot detection sensor 44 is. It consists of metallic band material and is, as shown in Fig. 7, slightly wavy to be in the slot to hold on to yourself. Your connections are central Area 36 led and there with as little free space as possible Line length connected to the control unit 43. Since it is very it is important to keep these connections as short as possible, could also be close to individual pan detection components the individual hotplates arranged in the thermal insulation his. In this way it is possible to be relatively unsharp and possibly faulty signals of a single wind and possibly unshielded in their connection area To evaluate the induction coil with sufficient accuracy.

Fig. 8 shows an embodiment in which the pot detection sensor 44 induction coil in the form of a single-winding Round wire into the material of the limiting part 28 close to heating zone 27, but thermally shielded, is embedded.

Fig. 9 shows an embodiment in which as a pot detection sensor 44, as in Figures 6 and 7, an upright Tape made of flat material is used, which, similar to that Heating conductor 25, in the heating element carrier 23 by pressing is embedded over part of its height. Against one too Strong warming can be, for example, reflective Coating may be provided on the belt. Beneficial for this pot detection coils is that the respective hotplate is formed without a surrounding sheet metal edge that could form an unwanted shield.

9 shows that an indicator lamp 42 designed as an LED for the hot display directly into a recess in one Recess of the limiting part 28 can be inserted and then shines through the plate.

CONNECTIONS

The arrangement described also allows the connection to be laid to design particularly cheap. For one, can by merging the most diverse regulatory and Control units on a large part of internal wiring can be dispensed with and, on the other hand, the interconnection can also the individual hotplates with the central control unit or other organs already during the production of the hotplates and with it the trough. With summary in a wiring harness 39, in which the cables are originally attached individual switching elements, for example the temperature limiters 32, are provided, can finally be a common one Plug (97 in Fig. 1) for connection to the input or setting devices may be provided.

Above all, however, is the wiring using a cable harness 39 or a connection matrix possible with exactly specified Connection lengths and positions can be prepared. For example, solid wire connections in corresponding channels of the limiting part 28 may be guided. An electrical connection is particularly preferred from ribbons or strips 55, which in corresponding Channels 56 are inserted in the limiting part 28. The canals can, for example, by offset stamps easily manufactured even within the limiting part become. The flat conductors 55 are inserted into them or inserted. But it is also possible to use appropriate Recesses in the parting plane between the boundary part and to carry the heating element support, being put together these parts are automatically included.

The heating conductor tapes can, for example, be made of nickel-plated Steel band exist, possibly by spot welding 57 be connected to each other. You can also already as corresponding matrix can be produced by punching. The lower electrical conductivity of iron can result from appropriate dimensions are balanced. In each The case is heat-resistant and light weldable conductors.

PRODUCTION METHOD

The production of the hob unit can be done in one continuous Process flow take place because the radiant heater no longer manufactured separately for the individual hotplates and need to be installed in a hob, but only when installing the hob unit individual basic components arise.

In detail, the manufacturing process can proceed as follows: In the prefabricated bowl-shaped metal trough 14 the fasteners, so the spacers 81 and Side brackets 82, 83 provided by die cuts in the bottom were bent up accordingly. Then the heating element support 23 with heating elements 25 fastened thereon automatically, i.e. possibly from a handling machine, diagonally (from swung in at the top right in Fig. 2) and in the recess 26 positioned. After that, in the same way Limiting part 28 pivoted in and between the side holder 82 and 83 introduced. Then the temperature limiter 32 with its sensor 31 inserted through the holes 87, 88, so that the limiting part 28 and thus the entire hotplate locked in position. The temperature limiter can thereby by means of snap elements 57 on the side holder 83 be engaged. These snap elements are on the Feeler facing side of the head are provided and can be made a centrally slotted sheet metal part with a barb-like Head exist that in a corresponding opening on Side holder 83 snaps into place.

Before or after installing the temperature limiter, depending on their position and arrangement also other control and Controls arranged in the central region 36 of the trough, for example the control device 43.

Electrical connection connections can already be made to the control and Controls can be provided by, for example at the temperature limiters 32 already strands in the intended Length and welded with finished ferrules. They are then combined into a wiring harness, the is led out together. Another option is there in bringing in a pre-made wiring harness that already prepared ends on both sides in the corresponding lengths and arrangements.

Subsequently, in particular in the embodiment according to FIG. 6 and 7, the pot detection sensors in the form preferably single-winding coils are pressed into the limiting part. This is followed by preferably automatic welding all connections, i.e. for example the one at the temperature limiters provided connections for the heating elements 25 etc.

If an input or setting field 40 directly on the trough is provided, this is introduced beforehand and at the same time with the other connections by welding the Connections interconnected.

The entire hob unit can then be tested undergo where not just the right wiring is checked, but also the heating elements and the controller in Function.

Together with the pot detection sensors 44, if provided a hot indicator lamp 42 in the limiting part introduced and then connected.

Possibly. could have put the glass ceramic plate on beforehand are, with a possibly in the embodiment of FIG Height adjustment of the individual hotplates automatically manufactures. The test is done when the plate is already assembled, in use, so that the Plate-related influences already taken into account in the test can be.

Claims (13)

1. Cooking hob unit with several heating elements (25) in at least one heating zone (13, 13a) located below a plate (17), particularly a glass ceramic plate and cooking points (12), particularly radiant cooking points containing a thermal insulation (22) and which are located in a flat material, such as sheet metal hob (14), characterized in that the thermal insulation of the cooking points (12) is positioned individually and directly at the hob (14).
2. Cooking hob unit according to claim 1, characterized in that the unit (11) together with an integrated control, regulating, monitoring and connection system forms a prefabricated, connectable component and preferably the control, regulating, monitoring and connection system contains all the control, regulating, monitoring and connecting devices except for the mains connection and optionally setting or input devices (40).
3. Unit according to claim 1 or 2, characterized in that at least one thermal insulation component (22) of each cooking point (12) is led directly to reception means (26, 82, 83) belonging to the hob (14) and/or the reception means (81, 82, 83) are so constructed at the hob (14) that in the case of a repair an independent cooking point is usable.
4. Unit according to one of the preceding claims, characterized in that each cooking point (12) contains two separate thermal insulation components (23, 28) and namely a tray-like heating element carrier shaped from pressed, pourable thermal insulating material such as silica aerogel and an annular boundary part surrounding the heating zone and formed from a relatively dimensionally stable, preferably fibre-free thermal insulating material such as Vermiculite TM, said boundary part being variably guided in its spacing from the hob (14) by preferably resilient spacers (81) and in particular the annular boundary part (28) and the heating element carrier (23) are movable vertically relative to one another and/or the annular boundary part (28) is received at the hob (14) by steady arms (82, 83) and fixed thereon by a brace preferably formed by a temperature sensor (31) of a thermal cutout (32) and which is in particular fixed as a result thereof and optionally the spacers and/or steady arms (81, 82, 83) or their fixing points on the bottom (20) of the hob (14) are preferably provided as prestamped and outwardly bendable sheet metal cutouts and/or are located on the hob bottom (20) in a grid adaptable to different sizes and arrangements of cooking points (12).
5. Unit according to one of the preceding claims, characterized in that the hob (14) is resiliently mounted in its spacing from the plate (17), preferably by spring means (95) located between the hob (14) and a frame-like plate carrier (93).
6. Unit according to one of the preceding claims, characterized in that in a central area (36) formed between the cooking points (12) are provided electrical connections (38), thermal cutouts (32), control sensors, connections for saucepan detection sensors (44) and/or residual heat indicating signalling devices (42) and optionally thermal cutouts (32) with a holder are directly fixed to the hob bottom and/or in the central area (36) are provided electronic components (43), particularly for a saucepan detection system, which is optionally thermally insulated and cooled by thermal decoupling and/or passive or active cooling means.
7. Unit according to one of the preceding claims, characterized in that a residual heat indicating system (42) for indicating a burning risk on contact with the cooking point (12) is constructed in time-controlled manner without a temperature sensor and/or is connected as a prewired unit to spring plug connections.
8. Unit according to one of the preceding claims, characterized in that in a boundary part (28) of the heating zone (13) is introduced an inductive sensor for a saucepan detection system more particularly comprising a single winding or turn, optionally by embedding or by inserting a preferably corrugated, flat material ring in a groove (75) emanating from the side of the boundary part (28) facing the plate (17) and/or the sensor is located in the marginal area of a heating element carrier (23), preferably as an upright standing flat material strip partly embedded in the heating element carrier (23).
9. Unit according to one of the preceding claims, characterized in that thermal insulation components (22) are made from different insulation materials and preferably in a relatively dimensionally stable thermal insulation component (28) are provided inserts (34) from a better heat insulating material, particularly in the area of an annular boundary part (28) surrounding the heating zone (13).
10. Unit according to one of the preceding claims, characterized in that the electrical connections of the cooking points, which preferably emanate from the associated thermal cutouts (32), are provided in prefitted manner thereon and on fitting are combined into a cable harness (39) optionally provided with a common multiple contact plug (97) and/or the electrical connections (38, 55) are integrated into the thermal insulation components (22) or are enclosed between the same and in particular placed in partly undercut channels (56) and optionally the electrical connections are constructed as flat conductors (55), preferably iron-based and are optionally constructed as a punched out matrix.
11. Unit according to one of the preceding claims, characterized in that the boundary part (28) is spanned by a ring (44), which optionally forms an induction coil for a saucepan detection system and is in particular formed from several ring sectors (28a) and/or the boundary part (28) and ring (44) form the outer boundary of the cooking point (12).
12. Unit according to claim 11, characterized in that the boundary part (28) is positively connected to the heating element carrier (23) and in particular the boundary part (28) has at least one recess (101, 106), in which engages a part (102) of the heating element carrier (23) and which is optionally located in the vicinity of a deformation of the heating element carrier (23).
13. Method for the manufacture of a cooking hob unit (11) according to one of the claims 1 to 12 with several electric heating elements (25) arranged below a plate (17), particularly a glass ceramic plate and cooking points (12), particularly radiant cooking points containing a thermal insulation, wherein

    a) heating element carriers (23) provided with electrical heating elements (25) are positioned on the bottom (20) of a sheet metal hob (14) common to all the cooking points (12),

    b) boundary parts (28) are fitted and positively locked via heating element carriers (23),

    c) in the vicinity of the cooking hob (11), particularly in a central area (36) are provided regulating, monitoring and control devices, optionally accompanied by the locking of the boundary parts (28),

    d) saucepan detection sensors (44), optionally constructed as induction coils, are fitted in the marginal area of the openings in the boundary part (28),

    e) optionally an input or setting panel (40) is installed,

    f) electrical connections (57) are automatically welded between the connection lines (38, 39, 55) and the heating elements, regulating, monitoring and control devices and optionally the saucepan detection sensors (44) and the input and setting panel (40),

    g) and subsequently the complete unit undergoes a test procedure.

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