EP1145670B1 - Heating device with heating elements for a water bed - Google Patents

Abstract

The device has electrical heating elements between a bed frame and safety foil and regulates the temperature of a metal plate beneath the safety foil. The heating elements are connected to the plate via a thermally conducting coating and consist of current and heat conducting metal elements held together by current conducting coupling elements and positive temperature coefficient heating elements that generate heat when carrying current. The device has electrical heating elements between a bed frame and safety foil and regulates the temperature of a metal plate fitted beneath the safety foil of a water bed core, The heating elements are thermally connected to the underside of the plate in a flat housing via a thermally conducting coating. The heating elements consist of several current and heat conducting metal elements (15-18) held together by force and/or shape locking by current conducting coupling elements (25,26) and positive temperature coefficient heating elements (19-24) held between them that generate heat when carrying current.

Description

In a heater of this type according to the DE 195 08 315 C1, the electrical heating elements made of electrical conductors from a pasty mixture Particles of precious metals, such as gold, silver or Ruthenium, as well as of ceramic components, such as glass and aluminum oxides, which are in the form of a hybrid Conductor loop on a ceramic plate from a Aluminum oxide substrate are baked. This electrical Conductors generate current through a heat, which over the ceramic plates as heat exchangers as well as over the well thermally conductive layer on the metal plate of the housing this heater is transmitted. The ceramic plates do not act as a heat generator, but only as pure heat exchanger of the electrically burned Resistance conductor loops generated at Stromdurchfluß Warmth. For this purpose, the heat-conducting layer, with which the ceramic plates on the underside of Metal plate are glued, made of an adhesive high Thermal conductivity. At the bottom of the rigid Metal plate is an NTC sensor arranged while the too leading the branded resistance wire conductors Power conductors are connected to a TRIAC, which also attached to the underside of the metal plate. Both the NTC sensor and the TRIAC are equipped with a Control device connected.

According to the DIN-EN 60335-2-66 of February 1996 may the temperature at the surface of a waterbed heater 60 ° C and the temperature of the surface of the Waterbed mattress should not exceed 37 ° C. Furthermore, the Temperature increase of the surface of the waterbed heater Do not exceed 125 ° C.

These requirements, the above-described Waterbed heating according to DE 195 08 315 C1 not enough, because on the one hand the NTC sensor on the metal plate attached and therefore only the temperature of the Metal plate measures and thus only the temperature of the Metal plate can regulate. Such an NTC sensor moves according to the principle that its electrical resistance is so smaller is the larger the temperature becomes and vice versa. As a result, the resistance increases when the cable breaks infinite and pretends a low temperature, the gives the controller the command to heat up.

Furthermore, this heating device can not different waterbed cores, i. Waterbed cores with different volumes of water, with different texture of the frame made of metal, Foam or wood as well as different Covers, for example, a covered and not covered waterbed core, because the each with different heat radiation losses the different aforementioned circumstances of NTC sensor can not be detected. It has the Experience has shown that the temperature of the waterbed core deviates significantly from its desired control temperature. Further, since the metal plate on its underside with relative small ceramic plates are equipped as heat exchangers, which occupy only a small area of the metal plate are in heating phase on the metal plate zones highest different temperatures available. Consequently it has a considerable on its radiation surface Temperature ripple on. Under this temperature ripple one understands deviations of the temperature the surface of the metal plate in the form of Temperature peaks directly above the ceramic conductor and Temperature decreases between the individual Ceramic conductors, which is noticeable in the heating phase power.

This in turn has the consequence that the NTC sensor a Temperature to the controller, which with the actual mean temperature of the heating phase is not but at best in the stationary state.

In WO 98/36664 is a waterbed heater in which below the metal plate a Layer with high electrical resistance installed and arranged thereon an electrical resistance wire heater is, in turn, through a layer with a high electrical resistance to the housing is shielded. This heater has similar disadvantages Afflicted as the aforementioned, namely that for example, at an unintentionally high load and Bend the metal plate completely or the conductor loops can partially tear, reducing the current flow is interrupted. This is especially true, especially between itself the electrical conductor loops and the underneath housing bottom often for thermal insulation an air layer or other insulating layer soft material, which is a deflection of the Metal plate favors. A protective device in the Failure of leading to it control line overheating the metal plate automatically and thus automatically under excludes all circumstances, is also in this Waterbed heating not found. It is a matter of no more and no less than one in diverse Variations known conventional resistance wire heating with all known disadvantages.

From this closest state of the art starting, the invention is based on the object, a Heating device of the type mentioned create, while avoiding the aforementioned disadvantages on the one hand overheating of the metal plate safe excludes and on the other hand, a reliable regulation of Temperatures of the waterbed core at different Water volumes and different texture of the Frame, be it metal, foam or wood, as well at different room temperatures and covers and with different ones Heat transfer conditions ensured.

This task will be described in connection with the beginning mentioned generic term solved according to the invention, that the heating elements of several power and / or positive fit by current-conducting coupling elements held together, current and heat conducting Metal elements and clamped in between, at Current flow heat generating PTC heating elements exist, and that the good heat-conducting layer between the bottom of the metal plate and the heating elements as Double-sided adhesive film layer with good current insulating properties is formed.

This training is the first time a Waterbed heating with real ceramic heating elements to procure, i. with such PTC heating elements at Stromdurchfluß directly generate the desired heat and not as in the prior art merely as Heat exchanger of a branded hybrid resistance conductor loop act. Since now the heating elements off several non-positive and / or positive by current-conducting Coupling elements held together current and thermally conductive metal elements, the entire Base surface of metal plate completely even and be heated without a noteworthy ripple.

In addition, the PTC heating elements provide one automatic and thus automatically entering Safety function, because namely their electrical Resistance at a temperature of e.g. 90 ° C rises steeply and goes to infinity at a temperature of 100 ° C, so that thereby the flow of current through the metal elements is interrupted and therefore overheating is excluded.

In an advantageous embodiment of the invention exist the metal elements made of aluminum or copper profiles large mass and thus also great storage capacity. The PTC heating element is advantageously made of barium carbonate, Titanium oxide and other additives produced while the Foil layer of a permanently elastic, with a Acrylic adhesive filled heat-conducting film consists.

The coupling element is advantageous by a resilient Contact clip formed, each two in phase Metal elements with the interposed PTC heating elements positive, energetic and positive coupled with each other. This way is done with simple Means an extremely compact overall heating element created on any interposed Adhesive coatings can do without. To the coupling of To simplify contact clips are the metal elements at their from the current-insulating and heat-conducting film opposite side with swallowtail-shaped Recesses for positive engagement of the Provided contact clips.

According to an advantageous embodiment of the invention the heating device has a total of four parallel mutually extending metal elements with a total of six interposed PTC heating elements below the Metal plate and the film layer as the overall heating.

After a particularly advantageous development of Invention will be the heating device of two Regulated NTC sensors, of which a first outside the Area of the metal plate in an outdoor area of the Housing is arranged such that it with the Water bed core is in direct measuring contact and of which a second in a conventional manner below the Metal plate is arranged. As a result, the second measures NTC sensor always the temperature of the metal plate and the first NTC sensor always the temperature of the waterbed core. Both NTC sensors come with a microcomputer connected, which evaluates both temperatures steadily and the Temperature of the metal plate controls so that the Water temperature of the waterbed core to the desired temperature which can be set on a controller increases. Thereby ensures that completely independent of the size of the Water volume, of completely different texture the waterbed frame, whether it be made of metal, Foam or wood is made and completely independent of the room temperature and the covering conditions of the Waterbed core always the desired Waterbed core temperature not only reached, but also is kept constant. The microcomputer is like that adjusted that the surface temperature of the metal plate Does not exceed 60 ° C. Further, at a fraction of a or both NTC sensors or a leading cable from the micro-computer through a plausibility detection of Exclusion of a malfunction ensured and thus both the temperature of the surface of the metal plate as Also, the temperature of the waterbed core on the after DIN standard permitted values limited.

Fig. 1 eine perspektivische Explosionsansicht auf ein Wasserbett mit einer zwischen einer Polsterung des Bettgestells und der Sicherheitsfolie angeordneten Heizungsvorrichtung,

Fig. 2 die Querschnittansicht durch ein Wasserbett mit einer zwischen der Polsterung des Bettgestells und der Sicherheitsfolie angeordneten Heizungsvorrichtung gemäß Fig. 1,

Fig. 3 die Ausschnittvergrößerung III von Fig. 2 eines Seitenbereiches der Wasserbettheizung.

Fig. 4 eine Explosionsansicht der aus der Metallplatte, mit Metallelementen mit dazwischen angeordneten PTC-Heizelementen und Koppelelementen bestehenden Heizungsvorrichtung,

Fig. 5 die Unteransicht der Heizungsvorrichtung bei abgenommenem Gehäuse,

Fig. 6 die Schnittansicht entlang der Linie VI - VI von Fig. 5,

Fig. 7 die Ausschnittvergrößerung VII von Fig. 6,

Fig. 8 ein Ersatzschaltbild der Heizungsvorrichtung von Fig. 4 und 5,

Fig. 9 ein Diagramm des elektrischen Widerstandes eines PTC-Heizelementes in Abhängigkeit von seiner Temperatur,

Fig. 10 die Ansicht in Richtung des Pfeils X von Fig. 11 auf ein Reglergehäuse mit dem Mikro-Computer und

Fig. 11 die Seitenansicht in Richtung des Pfeiles XI von Fig. 10.

An embodiment of the invention is shown in the drawings. Showing:

1 is an exploded perspective view of a waterbed with a arranged between a padding of the bed frame and the security film heating device,

2 shows the cross-sectional view through a waterbed with a heating device according to FIG. 1 arranged between the padding of the bed frame and the safety foil, FIG.

3 shows the detail enlargement III of FIG. 2 of a side region of the waterbed heater.

4 shows an exploded view of the heating device consisting of the metal plate, with metal elements with PTC heating elements and coupling elements arranged therebetween.

5 shows the bottom view of the heating device with the housing removed,

6 is the sectional view taken along the line VI - VI of Fig. 5,

7 shows the detail enlargement VII of FIG. 6, FIG.

8 is an equivalent circuit diagram of the heating device of FIGS. 4 and 5;

9 shows a diagram of the electrical resistance of a PTC heating element as a function of its temperature,

Fig. 10 is a view in the direction of arrow X of Fig. 11 on a controller housing with the micro-computer and

11 is a side view in the direction of arrow XI of Fig. 10.

The new heating device 1 for a waterbed 2 is in accordance with Figures 1 and 2 between a Padding 3 of a bed frame 4, which is made of metal, Plastic or wood can exist, and one Security film 5 is arranged. The regulator of Waterbed heater is with 6, which are flexible line cables with 7 and 7a and the plug is designated 8. On the in Trough shape designed security film 5 is the Waterbed core 9 laid. The trough-shaped Safety film 5 is intended to leak when the Wasserbettkerns 9 its entire water content catch. The waterbed core 9, the security film 5 and the padding 3 are wrapped by a Cover upper part 10, which with a cover lower part 10a the cover 10, 10a by means of a not shown as well as circumferential zipper at 10b is connected (see Fig. 2).

In Fig. 2 with Fig. 1 matching parts denoted by the same reference numerals. Of the Waterbed heating 1 should be in the waterbed core 9 located water 9a to the desired temperature to be heated. This water 9a is completely subject different heat losses due to radiation and by conduction, depending on whether, for example, on the Cover top 10 a top bed is present or not or depending on whether the frame 4 made of wood, metal or Foam exists. All previously known Waterbed heaters only measure with one NTC sensor 13 which is fixed to a metal plate 11, the Temperature of this metal plate 11. Accordingly, a such NTC sensor 13 only the temperature of this Metal plate 11 regulate. On the different Radiation and heat dissipation losses of the water 9a Within the waterbed core 9, this NTC sensor 13 have no influence.

According to Fig. 4, the inventive Heating device 1 from bottom to top of a well heat-insulating and, if possible, the downward Heat upwards by means of a coating 14b, e.g. made of aluminum or a vapor-deposited chrome layer reflective housing 14 made of plastic, four Metal elements 15-18 of extruded aluminum or Copper profiles from a total of six at current flow heat generating PTC heating elements 19-24, which are manufactured by electrically conductive coupling elements 25, 26 force and be held together positively and electrically conductive. Furthermore, one of the heating device 1 is a good heat-conducting and current-insulating layer 27, the between the bottom 11 a of the metal plate 11 and the Metal elements 15-18 and the PTC heating elements 19-24 is arranged. The coupling elements 25, 26 are either partially or completely in its middle area of one Current insulating layer 28, 28 a wrapped so that of the two coupling elements 25, 26 to avoid a Short circuit that between the ends 25a, 25b of the Coupling element 25 and the ends 26a, 26b of the Coupling element 26 lying metal element 16 and 17 in In this area no current contact to the Coupling elements 25, 26 has, but only the In phase metal elements 15 and 17 on the one hand and 16 and 18 on the other.

According to Figures 3 and 4, the Heating device 1 of two NTC sensors 12, 13th regulated, of which a first 12 outside the area the metal plate 11 at an outer region 14a of the Housing 14 is arranged such that it over the Security film 5 with the waterbed core 9 in direct Measuring contact is, whereas a second NTC sensor 13 in in a known manner with the bottom 11a of Metal plate 11 is above the film 27 in measuring contact. With the at least at their ends 25a, 25b and 26a, 26b leaf spring-like coupling elements 25, 26 are both the metal elements 15-18 and the six PTC heating elements 19-24 positive and positive as well as held together conductively. To reach for this purpose the ends 25a, 26b and 26a, 26b in cross section dovetail grooves 29 of the Metal elements 15-18 positive and non-positive. Thereby May be on adhesives or other bonding agents be dispensed to an excellent Heat transfer from the at Stromstoßdurchfluß heat generating PTC heating elements 19-24 on the To ensure metal elements 15-18.

FIGS. 5 and 6 show the heating device 1 in accordance with FIG. 4 in the assembled state Removed housing 14. In this case, with Fig. 4th matching parts with the same reference numbers designated. The figures 5 and 6 below the Metal plate 11 a strain relief 14c and Power cable 7a and the ground terminal 11b for the Metal plate 11. Parts matching with Fig. 4 are with denoted by the same reference numerals. This also applies to the Fig. 7.

From this Fig. 7 is the leaf-spring-like character the ends 25a, 25b and also the corresponding Ends 26a, 26b of the coupling elements 25, 26 and the The fact that after a single clipping behind this Ends 25a, 25b, 26a, 26b in the dovetail Grooves 29 of the metal elements 15-18 an automatic release is no longer possible. At the spring preload of Ends 25a, 25b of the coupling element 25 and the corresponding bias of the ends 26a, 26b of the Coupling element 26, both the metal elements 15-18 as well as the PTC heating elements 19-24 with appropriate Force and thus both good heat and electricity connected.

In Fig. 8 is an equivalent circuit diagram of Heating device 1 of Figures 4 and 5 shown. The in these figures matching parts are the same Reference numerals designates. A current path 30 is connected to the Coupling element 26 and a further current path 31 with the Coupling element 25 electrically connected.

About the current path 30, the alternating current flows in both directions over the end 26a of the Coupling element 26 in the metal element 16 through the both PTC heating elements 19, 20 in the metal element 15 and from there via the end 25a of the coupling element 25 in the Rung 31.

Once again the alternating current flows over the Current path 30 and the coupling element 26 via its end 26b into the metal element 18, from the latter through the two PTC heating elements 23, 24 in the metal element 17 and from there over the end 25b of the coupling element 25 in the Rung 31.

And finally, there is a flow of current over the Rung 30, the end 26 a of the coupling element 26 in the Metal element 16, from there through the two PTC heating elements 21, 22 in the metal element 17 and from there over the end 25b of the coupling element 25 in the Rung 31.

As a result, when applying an alternating current the ends 32 of the current paths 30, 31 all PTC heating elements 19-24 via the coupling elements 25, 26th and the metal elements 15-18 in both directions of the described passageways of the alternating current flowed through, creating heat. The degree of Heat generation and the achievable temperature depends from the composition of the PTC heating elements 19-24, from barium carbonate, titanium oxide and other additives consist. Depending on the composition can start from one certain temperature, the PTC heating element 19-24 its increase electrical resistance to current flow.

For a particular PTC heating element 19-24, which increases its electrical resistance R from about a temperature - here of about 90 ° C - is shown in Fig. 9. As this diagram shows, rises from about a temperature of 90 ° C, the electrical resistance R of the PTC heating element of 10 ³ Ω steadily and reaches at 150 ° C, a resistance of 10 ⁸ Ω. With increasing resistance, the current flow and thus also the heat generation of the PTC heating elements 19-24 decreases automatically.

Since according to the aforementioned DIN-EN 60335-2-66 from February, 1996 the temperature of the surface - here the Metal plate 11 - 150 ° C may not exceed due to the automation of the PTC heating elements 19-24 an automatic and in any case functioning as well no longer dependent on any rule elements Temperature limitation with guaranteed safety created.

Further, since the metal elements 15-18 either out Aluminum or copper profiles of large mass and thus large heat storage capacity exist, on the one hand the stationary state of heat transfer of Metal plate 11 not only very quickly and evenly achieved, but also a flow of current at low electrical resistance of the metal elements 15-18 ensuring that heat production is exclusive is left to the PTC heating elements 19-24.

The good heat conducting layer 27 between the Bottom 11a of the metal plate 11 and the PTC heating elements 19-24 and the metal elements 15-18 provided with good current insulating properties and consists advantageously of a permanently elastic, with a Acrylic adhesive filled heat-conducting foil. The permanent elasticity is particularly important in this case, so that does not have a Embrittlement deteriorates the heat transfer Air gap between the PTC heating elements 19-24 or Metal elements 15-18 on the one hand and the bottom 11 a of Metal plate 11 may arise on the other hand.

The trained as a resilient contact clips Coupling elements 25, 26 each couple two in-phase Metal elements 15-18 with the interposed PTC heating elements 19-24 both force, current and positively with each other. Otherwise they will required adhesive layers with the appropriate Problems of poorer power line due to electrical resistance of such adhesive layers dispensable. In addition, since the resilient Contact clips 25a, 25b; 26a, 26b of Coupling elements 25, 26 no dynamic loads are exposed, is a durable durability guaranteed.

The first, to measure the temperature of the Waterbed core 9 used NTC sensor 12 (see Fig. 3) and the second for measuring the temperature of the metal plate 11 used NTC sensor 13 are shown in FIGS and 11 connected to a microcomputer 33 which is itself is located in the controller housing 6. This micro-computer 33 continuously evaluates both temperatures and regulates the Temperature of the metal plate 11 such that the Water temperature of the water bed core 9 on the desired, set on the controller housing 6 Temperature rises. At the same time, the microcomputer 33 provides also that the surface temperature of the Metal plate 11 is limited to 60 ° C. The respectively desired temperature can be via a plus-minus switch 34 on the controller housing 6 on the corresponding Temperature scale 35 via diode strip 36 and thus be set without a hitherto conventional slider.

From this micro-computer 33 is in case of failure of a the two or both NTC sensors 12, 13 or at a Break of a leading line by one Plausibility detection the exclusion of a malfunction ensured and both the temperature of the surface of the Metal plate 11 as well as the temperature of the Waterbed core 9 limited.

In this case, the PTC elements 19-24 are anyway that, in the case of an error, e.g. in case of failure of the electronics or one of the two NTC sensors 12, 13, due to the increasing electrical resistance from a certain Temperature is a temperature limit below the maximum allowable temperature of 125 ° C automatically given is.

Since these PTC heating elements 19-24 of certain Ceramic elements exist, is thus also the first time a real ceramic waterbed heating created.

LIST OF REFERENCE NUMBERS

Heating device

1

water bed

2

lower part

3

bedstead

4

Sure Heist film

5

control device

6

flexible cable

7, 7a

plug

8th

Waterbed core

9

water

9a

Covering shell

10

Covering the lower part

10a

metal plate

11

Bottom of the metal plate 11

11a

NTC sensors

12, 13

Plastic housing

14

Exterior of the housing 14th

14a

heat-reflecting layer

14b

metal elements

15, 16, 17, 18

PTC heating elements

19, 20, 21, 22, 23, 24

coupling elements

25, 26

Ends of the coupling elements 25, 26th

25a, 25b, 26a, 26b

current insulating layer

28, 28a

dovetailed grooves the metal elements 15-18

29

rungs

30, 31

Ends of the current paths 30, 31

32

Micro Computer

33

Plus-minus switch

34

temperature scale

35

Diode light strip

36

electrical resistance

R

Claims (14)

1. A heating device (1) having a metal plate (11). a layer (27) with good thermal conductivity properties, and electrical heating elements for waterbeds, which is able to be arranged between a bed frame (4) and a safety foil (5), wherein the heating elements control the temperature of the metal plate (11), which is able to be attached beneath the safety foil (5) of a waterbed core (9) lying thereon, wherein the heating elements are connected to the underside of the metal plate (11) in a flat housing (14) via a layer (27) with good heat conducting properties, characterized in that the heating elements are made from multiple thermally and electrically conductive metallic elements (15-18), held together positively and non-positively by electrically conductive coupling elements (25, 26). and from PTC heating elements (19-24) clamped therebetween that generate heat when a current is passed through them, and that the layer with good heat conducting properties between the underside (11a) of the metal plate (11) and the heating elements (15-24) has the form of a foil layer (27) with good electrical insulating properties and being capable of adhesion on both sides.
2. The heating device according to Claim 1,
   characterized in that the metallic elements (15-18) are made from aluminium or copper profile sections of large dimensions and thus also large heat retaining capacity.
3. The heating device according to Claim 1 or 2,
   characterized in that the PTC heating elements (19-24) are made from barium carbonate, titanium oxide and other additives.
4. The heating device according to any of Claims 1 to 3,
   characterized in that the foil layer (27) is made from a permanently elastic, thermally conductive foil filled with an acrylate adhesive.
5. The heating device according to any of Claims 1 to 4,
   characterized in that the coupling element (25, 26) is made from a spring-loaded contact clip, each of which non-positively and electrically couples two in-phase metallic elements (15, 17; 16, 18) with one another with the PTC heating elements (19-24) arranged therebetween.
6. The heating device according to one or more of Claims 1 to 5,
   characterized in that the side of the metallic elements (15-18) facing away from the electrically insulating and thermally conductive foil sheet (27) is provided with dovetail-shaped recesses (29) for positive engagement with the contact clips (25, 26).
7. The heating device according to one or more of Claims 1 to 6.
   characterized in that multiple metallic elements (15-18), each with PTC heating elements (19-24) located therebetween, are arranged over almost the entire surface on the metal plate (11).
8. The heating device according to any of Claims 1 to 7,
   characterized in that it has a total of four metallic elements (15-18) extending parallel to each other with a total of six PTC heating elements (19-24) located therebetween underneath the metal plate (11) and the foil layer (27).
9. The heating device according to any of Claims 1 to 8,
   characterized in that the heating device (1) is regulated by two NTC sensors (12, 13), of which a first (12) is disposed in an outer area (14a) of the housing (14) outside the area of the metal plate (11) in such manner that it is in direct measuring contact with the waterbed core (9), and of which a second (13) is disposed underneath the metal plate (11) in known manner.
10. The heating device according to Claim 9,
    characterized in that the first NTC sensor (12), used to measure the temperature of the waterbed core (9), and the second NTC sensor (13), used to measure the temperature of the metal plate (13), are connected to a microcomputer (33) which evaluates both temperatures constantly and controls the temperature of the metal plate (11) such that the water temperature of the waterbed core (9) rises to the desired temperature, which can be adjusted at a controller (6).
11. The heating device according to Claims 9 and 10,
    characterized in that the microcomputer (33) limits the surface temperature of the metal plate (11) to 60°C.
12. The heating device according to any of Claims 1 to 11,
    characterized in that the PTC heating elements (19-24) are constructed in such a way that in the event of malfunction, e.g. if the electronic system and/or one of the NTC sensors (12. 13) fails, a temperature restriction below the maximum permitted temperature of 125°C is assured due to the increasing electrical impedance.
13. The heating device according to any of Claims 8 to 11,
    characterized in that if an NTC sensor (12, 13) fails or if a wire leading thereto from the microcomputer (33) breaks, a plausibility recognition function ensures that misoperation is precluded and that the temperatures of both the surface of the metal plate (11) and of the waterbed core (9) are restricted.
14. The heating device according to any of Claims 10 to 13,
    characterized in that the microcomputer (33) and the controller (6) are accommodated in a common housing.

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