Patent Application
20160302263
This application claims priority to European Application No. 15163139.7, filed Apr. 10, 2015, the contents of which are hereby incorporated herein in its entirety by reference.
The invention relates to an induction hob and also to a flexible support for a plurality of sensor coils for installation into an induction hob below the hob plate of the induction hob.
U.S. Ser. No. 14/951,182, which has the application date of Nov. 24, 2015, and was not a prior publication, discloses arranging a plurality of sensor coils in an induction hob below the hob plate of the induction hob and above induction heating coils. In this case, the sensor coils are arranged in accordance with a specific pattern.
EP 2312908 A1 discloses arranging a large number of sensor coils in a layer between the hob plate and induction heating coils in a similar induction hob. In this case, the sensor coils can be applied to a flat support, for example by means of silk-screening methods or screen printing.
The invention is based on the problem of providing an induction hob of the kind mentioned in the introductory part and also a flexible support having sensor coils on it for installation into an induction hob of the kind, it being possible to solve problems in the prior art with the induction hob and flexible support, and it being possible, in particular, to provide simple and cost-effective production which is also suitable for series production.
This problem is solved by an induction hob and also by a flexible support. Advantageous and preferred refinements of the invention are the subject matter of the further claims and will be explained in greater detail in the text which follows. In the process, some of the features will be described only for the induction hob or only for the flexible support. However, irrespective of this, the features are intended to also be able to apply both for the induction hob and also for the flexible support independently. The wording of the claims is incorporated in the description by express reference.
It is provided that the induction hob has a hob plate, at least one induction heating coil which is arranged below the hob plate, advantageously a plurality of induction heating coils, and generally a plurality of sensors or inductive sensors, such as sensor coils for example, which are arranged below the hob plate and above the induction heating coil. Instead of sensor coils, other inductively acting sensors could also be provided and, under certain circumstances, even capacitive sensors, advantageously in order to be able to detect the presence of a pot on the hob plate above the sensors. Particularly advantageously, one temperature sensor or a plurality of temperature sensors can also be provided, wherein a temperature sensor can be arranged preferably close to the sensor coil or directly on the sensor or on the sensor coil.
The sensors or sensor coils are arranged on a flat flexible support according to the invention and electrical conductors make electrical contact with the sensors or sensor coils on the flat flexible support. The flexible support is composed of a flat material or is produced from a flat material of this kind. Any temperature sensors which may be present are likewise arranged on the flexible support and electrical conductors likewise make electrical contact with the temperature sensors on the flexible support. The flexible support has a single common connection device for electrical contact to be made for the sensor coils which are arranged on the flexible support and any temperature sensors which may be present. Therefore, the connection process can be carried out in a quick and reliable manner.
The flexible support according to the invention advantageously has a textile support part which is composed of a textile material, preferably of mechanically stable and temperature-resistant fibres for use in the induction hob. Glass fibres are considered to be advantageous, but other sufficiently temperature-resistant artificial fibres or other fibres such as aramid or Kevlar fibres can also be used as an alternative. The electrical conductors can be applied to the textile support part and fixed on the textile support part. The electrical conductors can be, for example, thin wires, either monofilaments or multi-filaments, which run on one side of the support, advantageously with a blank or conductive surface. It is also possible for the wires to run on both sides of the flexible support or of the textile support part. The electrical conductors can be fixed, for example, firstly by adhesive bonding or secondly by overstitching.
The sensors or sensor coils and possibly temperature sensors are also applied to the support part and fixed there. Owing to a textile support part of this kind, it is possible to be able to avoid expensive and technically complicated conductor foils, which are to be provided with conductors in a complicated manner, or so-called flexible printed circuits. This saves costs. At the same time, a textile support part of this kind can be deformed considerably more flexibly and simply than a conductor foil or flexible printed circuit.
The induction hob advantageously has at least two induction heating coils next to one another below the hob plate, preferably at least four induction heating coils, for example, also six or eight. In this case, all of the induction heating coils can be of the same size and/or of identical design, for example as is known from the abovementioned document U.S. Ser. No. 14/951,182. Approximately rectangular induction heating coils of this kind allow the surface of the induction hob to be largely completely covered without relatively large gaps between the induction heating coils.
In one refinement of the invention, at least two sensor coils can be provided for each induction coil and can be associated with the induction coil, for example, one sensor coil in the centre of the induction heating coil and one sensor coil in the edge region of the induction heating coil, under certain circumstances with slight coverage. Furthermore, at least one temperature sensor can be provided for each induction coil, but advantageously two temperature sensors are also provided. In an advantageous refinement of the invention, one temperature sensor is provided for each sensor coil, wherein a temperature sensor of this kind is arranged just close to the sensor coil. A sensor coil can have, in general, a free region without turns, particularly advantageously in the central region of the free region or in the centre of the free region. A temperature sensor can advantageously be arranged in this free region.
It is possible for a sensor coil and a temperature sensor to form a structural unit together, and in the process in each case have dedicated electrical connections, but with the option of the electrical connections potentially being combined for quicker and easier electrical connection. To this end, the two parts could be injection-moulded, adhesively bonded or encapsulated for integral strength. As an alternative and advantageously, a temperature sensor is arranged on the sensor coil or in the central region of the sensor coil, but not in the form of a structural unit and not mechanically connected to the sensor coil. In this case, the expenditure on assembly is somewhat higher, but standard components can be directly and individually installed.
A sensor coil in the form of an inductive sensor or generally in the form of a sensor can be wound flat with a maximum of two to three layers. This avoids an excessively high structural height for the induction hob overall and an excessively large distance between the induction heating coils and the hob plate. A sensor coil can have between 10 or 20 and 100 or 200 turns, depending on the desired level of sensitivity.
A temperature sensor can be designed in different ways. A standard component of so-called through-hole technology (THT) construction with two connection wires which can be easily connected to the electrical conductors on the flexible support or the textile support part is advantageous. Surface-mounted device (SMD) components are suitable only when mounting and electrical connection to the conductors is possible by means of soldering.
In a refinement of the invention, an additional flat rigid support which bears against the flexible support or textile support part, in particular in order to stabilize the flexible support or textile support part and/or to improve handling and mounting in the induction hob, can be provided. Therefore, this flat rigid support runs between the at least one induction heating coil and the bottom face of the hob plate. In this case, the flat rigid support should be mounted with a spring action in relation to the induction heating coil. The flat rigid support can completely cover the flexible support and/or the sensors or sensor coils which are arranged on the flexible support.
In a refinement of the invention, it is possible to arrange the flat rigid support between the induction heating coils and the flexible support. In this way, it is easier to accurately place or mount the flexible support above the at least one induction heating coil. The one induction heating coil or the plurality of induction heating coils specifically do not have a continuous flat and closed surface, and therefore positioning and/or displacement is often difficult. Furthermore, a uniform height level of the sensors or sensor coils and therefore also a uniform distance from the hob plate can be defined owing to the sensors or sensor coils bearing on the flat rigid support.
In a further refinement of the invention, it is possible for an abovementioned flat rigid support to bear against the bottom face of the hob plate and run above the sensors or sensor coils. Therefore, direct bearing of the sensors or sensor coils against the bottom face of the hob plate can be avoided.
In a further advantageous refinement of the invention, two additional flat rigid supports are provided, the additional flat rigid supports approximately overlapping over their area or covering the flexible support with the sensors and sensor coils which are arranged on it at least on both sides. The two flat rigid supports together with the flexible support between them can even form one structural unit in a manner connected to one another, this structural unit then being very easy to mount.
In one refinement of the invention, the flexible support can have a separate connection support, wherein this separate connection support once again has or forms the abovementioned common connection device. The separate connection support can overlap the flexible support or the textile support part and be fastened on the flexible support or textile support part by way of an end region. Furthermore, the textile support part and, respectively, the electrical conductors which are arranged on the textile support part can make electrical contact with the separate connection support or the separate connection support can be connected to the textile support part or the electrical conductors which are arranged on the textile support part. A separate connection support of this kind can project slightly from the textile support part in the manner of a connection cable. In this case, the connection support can be a component which was originally separate from the textile support part and has been subsequently connected to the textile support part. The connection support can advantageously also be composed of a different flexible material, particularly advantageously can be in the form of a foil support or conductor foil or flexible printed circuit with conductor tracks applied to it in a conventional manner.
Since the common connection device of the flexible support has to be connected to a mating connection of the induction hob during assembly of the induction hob, this usually being performed manually and requiring manual intervention, it is advantageous here to use a more robust and insensitive material than that of the textile support with the electrical conductors applied or stitched to it. It is possible to design the separate connection support to be much smaller than the textile support part, so that less of a more complicated and expensive material like the foil supports or flexible printed circuits is required. In this case, the connection support corresponds substantially to a kind of flat cable with a certain width but a very small thickness. When the textile support part is joined to the connection support, the conductor tracks of the connection support then also have to be connected to the electrical conductors on the textile support part. To this end, contact-connections, in particular in the form of contact fields, can be provided at an end region, which is opposite the end region with the common connection device, in the case of an elongate connection support. The contact-connections can extend over at least one third, preferably at least half, of the length of the connection support. The contact-connections are advantageously arranged in a row so as to run on or close to at least one outer side, advantageously on both outer sides.
The end region with the common connection device can project a few centimetres beyond the textile support part, for example, at most 10 cm to 15 cm. The flexible support preferably has only one single connection support of this kind with a total of one single connection device in the form of, for example, a plug-in connection apparatus which allows quick and easy electrical connection.
When the contact-connections of the separate connection support make electrical contact with the electrical conductors on the textile support part, electrical contact can be established by contact-pressure in the first instance. A mechanical connection can be improved by conductive adhesive or conductive paste. Soldering can also be performed depending on the material and heat resistance of the separate connection support, but soldering is usually not recommended on account of the relatively high temperatures in an induction hob.
One advantageous connection option is when the contact-connections of the separate connection support and the electrical conductors of the textile support part are held together by bent-over contact clips. To this end, a recess or a hole can run through the separate connection support and the textile support part next to the location of the connection of the separate connection support and the electrical conductors, advantageously as close as possible to the contact which is to be established or the connection which is to be established. In this case, a contact clip which has not yet been bent over can then be passed through and then bent over in a U-shape at least to such an extent that the two lateral U-limbs are bent towards one another and, in the process, press together the contact-connection of the separate connection support and the electrical conductor of the textile support part. A connection technique of this kind is known in the automotive sector by the term “splice technology”, a kind of crimping technique. If recesses of this kind through the separate connection support and the textile support part are produced next to the connection, which is to be established, on both sides, a clip can be bent over as it were once, this producing an even better connection. A contact clip of this kind can be composed of a relatively thin material, preferably a kind of flat wire. The requisite mechanical forces are not particularly large. Furthermore, fastening which is sufficiently stable overall is produced in the case of a large number of connections of this kind, which are to be established, between the separate connection support and the textile support part.
These and further features can be gathered from the claims as well as from the description and the drawings, wherein the individual features can each be implemented in their own right or in groups in the form of sub-combinations in the case of an embodiment of the invention and in other fields, and may represent advantageous and inherently patentable embodiments for which protection is claimed here. The subdivision of the application into individual sections and sub-headings do not restrict the general validity of the statements made therein.
Exemplary embodiments of the invention are illustrated in the drawings and will be explained in greater detail in the text which follows. In the drawings:
The textile support part 13 is produced from a fibre material, here woven. It is advisable to use appropriate fibres, such as glass fibres for example, for the temperatures of 250° C. to 270° C. which occur when used in an induction hob. The free edges could be lined for this purpose.
A connection support 15 is applied to the textile support part 13 or overlaps the textile support part. The connection support 15 is advantageously in the form of a so-called flexible printed circuit and can be a conductor foil with a large number of conductor tracks, not illustrated here, which are integrally formed on it. In its left-hand-side free end region 27, the connection support 15 has a plug-in connection 28 together with a laterally projecting holding lug 29. In this region, mechanical stabilization or reinforcement can be provided on the connection support, for example by an adhesively-bonded printed circuit board or a plurality of adhesively bonded layers of the same material. The holding lug 29 serves to provide a better grip when manually connecting the plug-in connection 28.
In the right-hand-side end region which overlaps the textile support part 13, the connection support 15 has a large number of recesses 24 in two rows, narrow webs 25 running between the recesses. The recesses serve to fasten the connection support 15 on the textile support part 13 and also to electrically connect the connection support and the textile support part.
In
Conductor wires 31 of this kind run on the textile support part 13 from the webs 20 and, respectively, 22 between recesses 19 and, respectively, 21 to the webs 25 of the recesses 24 in the connection support 15. These recesses 24 and webs 25 are specifically provided in identical form and arrangement precisely thereunder in the textile support part 13 beneath the connection support 15. The connection support 15 has, on its bottom face, blank contact fields, not illustrated here, in a manner associated with the webs 25 of the connection support 15. These contact fields are passed to plug-in connection contacts 30 of the plug-in connection 28 at the free end region 27 by means of conductor tracks 33 on the bottom face of the connection support 15.
As is clear from
The conductor wires 31 lead as far as the webs 20 and, in this case, are fixedly stitched up to shortly in front of the webs. Here, a temperature sensor 44 in the form of an abovementioned THT component is placed onto the textile support part 13. The temperature sensor 44 has two connection wire legs 45a and 45b which are bent away and likewise lie on the webs 20, where the ends of the two blank conductor wires 31 also lie. Here, they are electrically connected and mechanically fastened.
Two further conductor wires 31 run on the right-hand side on the webs 22 between the recesses 21a to 21c. The further conductor wires are also fixedly stitched up to the blank ends by a stitching thread 32.
A sensor coil corresponding to
In the enlarged sectional illustration for explaining the connection technique,
The connection of the connection wire legs 45a and 45b of the temperature sensor 44 to the respective connection wires 31 in the form of an electrical contact-connection and in the form of fastening to the textile support part 13 takes place as illustrated in
In
A detail of an induction hob 50 according to the invention which has a conventional hob plate 51 is illustrated in
On the basis of
Furthermore, instead of the flat sensor coils 35, other inductive sensors could also be used. In a yet further alternative, the sensors could be capacitive sensor elements which can likewise be used for pot identification, as is described, for example, by DE 102004016631 A1 to which reference is made in this respect.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15163139.7 | Apr 2015 | EP | regional |
