EP1145670A2 - 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

The invention relates to a heating device electric heating elements for waterbeds between a bed frame and a security film is arranged and regulates the temperature of a metal plate that is under the Safety film of a water bed core lying on it is attached, the heating elements with the bottom the metal plate in a flat case over a well thermally conductive layer are thermally connected.

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

According to DIN-EN 60335-2-66 from February 1996 the temperature on the surface of a waterbed heater 60 ° C and the temperature of the surface of the Do not exceed waterbed mattress 37 ° C. Furthermore, the Temperature increase of the surface of the water bed heating Do not exceed 125 ° C.

The above can meet these requirements Water bed heating according to DE 195 08 315 C1 is not are sufficient because the NTC sensor on the metal plate attached and therefore only the temperature of the Metal plate measures and therefore only the temperature of the Can regulate metal plate. Such an NTC sensor moves on the principle that its electrical resistance all the more is smaller, the higher the temperature and vice versa. If the cable breaks, the resistance rises accordingly infinite and pretends a low temperature that gives the controller the command to heat up.

Furthermore, this heating device cannot different waterbed cores, i.e. Waterbed cores with different water volumes, with different texture of the metal frame, Foam or wood as well as different Covers, such as a covered and not covered waterbed core, because the different heat radiation losses the different circumstances mentioned above NTC sensor can not be detected. The Experience has shown that the temperature of the waterbed core deviates significantly from its desired control temperature. Furthermore, since the metal plate on its underside with relative small ceramic plates as heat exchangers, that take up only a small area of the metal plate zones in the heating phase on the metal plate different temperatures available. Consequently has a significant radiation surface Temperature ripple. Below this temperature ripple one understands deviations in temperature the surface of the metal plate in the form of Temperature peaks directly above the ceramic conductor and Temperature drops between each Ceramic ladders, which is noticeable in the heating phase makes.

This in turn means that the NTC sensor has a Forwarding temperature to the controller, which with the actual mean temperature of the heating phase is not matches, but at most in the stationary state.

In WO 98/36664 there is a water bed heater have been disclosed, in which a below the metal plate Layer with high electrical resistance attached and an electrical resistance wire heater is arranged thereon which is in turn a layer with a high electrical resistance to the housing is shielded. This heater has similar disadvantages afflicted like the one mentioned at the beginning, namely that for example with an unintentionally high load and Deflection of the metal plate completely or the conductor loops can partially tear, causing the current flow is interrupted. This is all the more true, especially since there is between the electrical conductor loops and the one below housing bottom often for thermal insulation an air layer or another insulation layer soft material, which is a deflection of the Favored metal plate. A protective device that the Failure of a control line leading to it overheating the metal plate automatically and therefore automatically under excludes all circumstances, is also with this Water bed heating not found. It is a matter of no more and no less than one in diverse Variations known with conventional resistance wire heating all known disadvantages.

From this closest prior art starting, the invention has for its object a Heating device of the type mentioned create that while avoiding the aforementioned drawbacks on the one hand, overheating of the metal plate safely excludes and on the other hand a reliable regulation of the Temperatures of the water bed core at different Water volumes and different nature of the Frame, be it made of metal, foam or wood, as well at different room temperatures and covers and thus with different Guaranteed heat transfer conditions.

This task is in conjunction with the beginning solved generic term according to the invention solved by that the heating elements from several force and / or form-fitting through current-conducting coupling elements held together, current and heat conductive Metal elements and clamped between them Current flow through 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 Water bed heating with real ceramic heating elements created, i.e. with such PTC heating elements, which at Current flow directly generate the desired heat and not as in the prior art just as Heat exchanger of a burned-in hybrid resistance conductor loop act. Now that the heating elements are off several non-positively and / or positively by current-conducting Coupling elements held together by electricity and heat-conducting metal elements, the entire Bottom surface of the metal plate completely even and can be heated without a ripple worth mentioning.

In addition, the PTC heating elements offer a automatic and thus automatically occurring Safety function, because its electrical Resistance at a temperature of e.g. 90 ° C rises steeply and goes towards infinity at a temperature of 100 ° C, so that the current flow through the metal elements is interrupted and consequently overheating is excluded.

In an advantageous development of the invention the metal elements made of aluminum or copper profiles large mass and thus also large storage capacity. The PTC heating element is advantageously made of barium carbonate, Titanium oxide and other additives manufactured while the Film layer from a permanently elastic, with a Acrylic adhesive-filled thermal foil.

The coupling element is advantageously of a resilient Contact bracket formed, each two in phase Metal elements with the arranged in between PTC heating elements are non-positive, current and positive couples with each other. This way, with simple A very compact overall heating element created, which is placed on any in between Can do without adhesive layers. To couple the Simplifying contact clips are the metal elements on their from the current-insulating and heat-conducting film opposite side with dovetail-shaped Recesses for positive engagement of the Provide contact clips.

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

After a particularly advantageous development of Invention is the heating device of two NTC sensors regulated, a first of which outside the Area of the metal plate in an outer area of the Housing is arranged so that it with the Waterbed core is in direct measurement contact and of which a second in a manner known per se 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 are with a micro-computer connected, which continuously evaluates both temperatures and the Temperature of the metal plate controls so that the Water temperature of the water bed core to the desired one adjustable temperature increases on a controller. Thereby will ensure that regardless of the size of the Volume of water, of completely different nature of the waterbed frame, be it made of metal, Foam or wood is made and completely independent of the room temperature and the coverage of the Waterbed core always the desired Water bed core temperature not only reached, but also is kept constant. The microcomputer is like this set that the surface temperature of the metal plate Does not exceed 60 ° C. Furthermore, in the event of a break, a or both NTC sensors or a line leading to them from the micro-computer through a plausibility detection of the Exclusion of a malfunction ensured and thus both the temperature of the surface of the metal plate and also the temperature of the waterbed core to that after the DIN standard permissible 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. Show:

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

2 shows the cross-sectional view through a water bed with a heating device according to FIG. 1 arranged between the upholstery of the bed frame and the security film,

Fig. 3 shows the detail enlargement III of Fig. 2 of a side region of the water bed heater.

4 is an exploded view of the heating device consisting of the metal plate, with metal elements with PTC heating elements and coupling elements arranged in between,

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

6 shows the sectional view along the line VI-VI of FIG. 5,

7 shows the enlarged detail VII of FIG. 6,

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

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

Fig. 10 is the 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. 10th

The new heating device 1 for a water bed 2 is according to 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 arranged. The regulator of Waterbed heater is at 6 which are flexible conduit with 7 and 7a and the connector is designated 8. On the in Trough shape designed security film 5 is the Waterbed core 9 placed. The tub-shaped Safety film 5 is intended to be used if the Water bed core 9 whose total water content to catch up. The water bed core 9, the security film 5 and the padding 3 are enveloped by one Cover upper part 10, which with a cover lower part 10a the cover 10, 10a by means of a not shown and circumferential zipper is connected at 10b (see Fig. 2).

In Fig. 2 with Fig. 1 matching parts with the same reference numerals. Of the Water bed heating 1 should be in the water bed core 9 located water 9a to the desired temperature be heated. This water 9a is completely subject different heat losses through radiation and by heat conduction, depending on whether, for example, on the Cover top 10 an upper bed is present or not or depending on whether the frame 4 made of wood, metal or There is foam. All previously known Waterbed heaters only measure with one NTC sensor 13, which is attached to a metal plate 11, the Temperature of this metal plate 11. Accordingly, a such NTC sensor 13 only the temperature of this Regulate metal plate 11. The different ones Radiation and heat dissipation losses of water 9a This NTC sensor 13 can be located within the water bed core 9 have no influence.

4 there is the inventive Heater 1 from the bottom up from a good heat-insulating and, if possible, the one facing downwards Upward heat by means of a coating 14b, e.g. made of aluminum or a vapor-deposited chrome layer reflective housing 14 made of plastic, of four Metal elements 15-18 made of extruded aluminum or copper profiles from a total of six with current flow heat-generating PTC heating elements 19-24 by current-conducting coupling elements 25, 26 force and are held together in a form-fitting and electrically conductive manner. Furthermore, the heating device 1 is a good one heat-conducting and current-insulating layer 27, the between the bottom 11a 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 the middle of one current-insulating layer 28, 28a encased so that the two coupling elements 25, 26 to avoid a Short circuit between the ends 25a, 25b of the Coupling element 25 and the ends 26a, 26b of the Coupling element 26 lying metal element 16 or 17 in no electrical contact to the area Coupling elements 25, 26, but only that in-phase metal elements 15 and 17 on the one hand and 16 and 18 on the other hand.

According to Figures 3 and 4, the Heating device 1 of two NTC sensors 12, 13 regulated, a first 12 outside the area the metal plate 11 on 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 made, whereas a second NTC sensor 13 in in a known manner with the bottom 11a of the Metal plate 11 is in measuring contact via the foil 27. With at least at their ends 25a, 25b or 26a, 26b Coupling elements 25, 26 designed in the manner of leaf springs both the metal elements 15-18 and the six PTC heating elements 19-24 non-positively and positively as well held together in a conductive manner. Grab for that purpose the ends 25a, 26b and 26a, 26b in cross section dovetail grooves 29 of the Metal elements 15-18 positively and non-positively. Thereby can be on glue or other fasteners to be waived for an excellent Heat transfer from those with surge current flow heat-generating PTC heating elements 19-24 on the Ensure metal elements 15-18.

FIGS. 5 and 6 show the heating device 1 4 in the assembled state removed housing 14. With FIG. 4 matching parts with the same reference numbers designated. Figures 5 and 6 show below the Metal plate 11 a strain relief area 14c and Power cable 7a and the ground connection 11b for the Metal plate 11. With Fig. 4 matching parts are with the same reference numerals. That also applies to the Fig. 7.

From this Fig. 7, the leaf spring-like character the ends 25a, 25b and accordingly also the Ends 26a, 26b of the coupling elements 25, 26 and the The fact that after a single clip behind this Ends 25a, 25b, 26a, 26b into the dovetail-shaped Grooves 29 of the metal elements 15-18 an automatic release is no longer possible. With the spring preload the 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 corresponding Power and therefore both good heat and electricity conductive connected.

8 is an equivalent circuit diagram of the Heating device 1 of Figures 4 and 5 shown. The parts in these figures are the same Designated reference numbers. A current path 30 is with the Coupling element 26 and a further current path 31 with the Coupling element 25 electrically connected.

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

The alternating current flows again over the Current path 30 and the coupling element 26 via its end 26b into the metal element 18, from this 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 current flow over the Current path 30, the end 26a 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.

This means that when an AC current is applied the ends 32 of the current paths 30, 31 all PTC heating elements 19-24 via the coupling elements 25, 26 as well as the metal elements 15-18 in both directions of the described current passages from the alternating current flow through, which generates heat. The degree of Heat generation and the achievable temperature depends depending on the composition of the PTC heating elements 19-24, those made of barium carbonate, titanium oxide and other additives consist. Depending on the composition, from one certain temperature, the PTC heating element 19-24 increase electrical resistance to current flow.

For a specific 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, the electrical resistance R of the PTC heating element of 10 ³ Ω rises steadily from about a temperature of 90 ° C. and reaches a resistance of 10 ⁸ Ω at 150 ° C. With increasing resistance, the current flow and thus the heat generation of the PTC heating elements 19-24 is automatically reduced.

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

Furthermore, since the metal elements 15-18 either made Large or large aluminum or copper profiles great heat storage capacity exist on the one hand steady state of heat transfer the Metal plate 11 not only very quickly and evenly reached, but also a current flow at low electrical resistance of the metal elements 15-18 ensured, whereby the heat generation exclusively left to the PTC heating elements 19-24.

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

The trained as resilient contact clips Coupling elements 25, 26 each couple two in phase Metal elements 15-18 with those arranged in between PTC heating elements 19-24 both force, current and with each other. Otherwise required adhesive layers with the appropriate Problems with a poorer power line due to the electrical resistance of such adhesive layers dispensable. Since also the resilient Contact clips 25a, 25b; 26a, 26b of Coupling elements 25, 26 no dynamic loads exposed is permanent durability guaranteed.

The first to measure the temperature of the Water bed core 9 used NTC sensor 12 (see FIG. 3) and the second for measuring the temperature of the metal plate 11 NTC sensor 13 used are according to FIGS. 10 and 11 connected to a microcomputer 33, which itself is located in the controller housing 6. This micro computer 33 continuously evaluates both temperatures and controls them 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. The microcomputer 33 takes care of this also for the fact that the surface temperature of the Metal plate 11 is limited to 60 ° C. The each desired temperature can be set using a plus-minus switch 34 on the controller housing 6 on the corresponding Temperature scale 35 per diode light strip 36 and thus can be set without a slider that was previously common.

This micro-computer 33 will in the event of a failure of the two or both NTC sensors 12, 13 or one Break of a line leading to them by a 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 Water bed core 9 limited.

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

Because these PTC heating elements 19-24 from certain Ceramic elements exist, it will be one for the first time real ceramic waterbed heating created.

Reference symbol list:

Heater

1

Waterbed

2nd

Lower part

3rd

Bed frame

4th

Security film

5

Control device

6

flexible cable

7, 7a

plug

8th

Waterbed core

9

water

9a

Cover top

10th

Cover lower part

10a

Metal plate

11

Underside of the metal plate 11

11a

NTC sensors

12, 13

Plastic housing

14

Outside area of the housing 14

14a

heat reflective 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, 26

25a, 25b, 26a, 26b

current insulating layer

28, 28a

dovetail-shaped grooves the metal elements 15-18

29

Current paths

30, 31

Ends of current paths 30, 31

32

Micro-computer

33

Plus-minus switch

34

Temperature scale

35

Diode light strip

36

electrical resistance

R

Claims (14)

Heating device with electrical heating elements for water beds, which is arranged between a bed frame and a safety film and regulates the temperature of a metal plate which is attached under the safety film of a water bed core lying thereon, the heating elements with the underside of the metal plate in a flat housing via a highly heat-conducting Layer are connected in a heat-conducting manner, characterized in that the heating elements consist of a plurality of non-positively and / or positively held together by current-conducting coupling elements (25, 26), current- and heat-conducting metal elements (15-18) and clamped therebetween, PTC heating elements generating heat when the current flows through ( 19-24), and that the heat-conducting layer between the underside (11a) of the metal plate (11) and the heating elements (15-24) is designed as a double-sided adhesive film layer (27) with good current-insulating properties. Heating device according to claim 1, characterized in that the metal elements (15-18) consist of aluminum or copper profiles of large mass and thus great heat storage capacity. Heating device according to claim 1 or 2, characterized in that the PTC heating elements (19-24) consist of barium carbonate, titanium oxide and other additives. Heating device according to one of claims 1 to 3, characterized in that the film layer (27) is made of a permanently elastic heat-conducting film filled with an acrylate adhesive. Heating device according to one of claims 1 to 4, characterized in that the coupling element (25, 26) is formed by a resilient contact clip, each of two in-phase metal elements (15, 17; 16, 18) with the PTC heating elements (19 -24) non-positively, positively and positively coupled. Heating device according to one or more of claims 1 to 5, characterized in that the metal elements (15-18) on their side facing away from the current-insulating and heat-conducting film layer (27) with dovetail-shaped recesses (29) for positive engagement of the contact clips (25, 26 ) are provided. Heating device according to one or more of claims 1 to 6, characterized in that a plurality of metal elements (15-18) with PTC heating elements (19-24) located between them are arranged almost over the entire surface of the metal plate (11). Heating device according to one of claims 1 to 7, characterized in that it comprises a total of four parallel metal elements (15-18) with a total of six PTC heating elements (19-24) arranged between them below the metal plate (11) and the film layer (27) having. Heating device according to one of claims 1 to 8, characterized in that the heating device (1) is controlled by two NTC sensors (12, 13), a first one (12) outside the area of the metal plate (11) in an outer area ( 14a) of the housing (14) is arranged such that it is in direct measurement contact with the waterbed core (9) and a second one (13) of which is arranged below the metal plate (11) in a manner known per se. Heating device according to claim 9, characterized in that the first NTC sensor (12) used to measure the temperature of the water bed core (9) and the second NTC sensor (13) used to measure the temperature of the metal plate (11) with a micro -Computer (33) are connected, which continuously evaluates both temperatures and regulates the temperature of the metal plate (11) in such a way that the water temperature of the water bed core (9) rises to the desired temperature which can be set on a controller (6). Heating device according to claims 9 and 10, characterized in that the micro-computer (33) limits the surface temperature of the metal plate (11) to 60 ° C. Heating device according to one of claims 1 to 11, characterized in that the PTC heating elements (19-24) are designed such that in the event of a fault, for example in the event of failure of the electronics and / or one of the NTC sensors (12, 13), automatically the increasing electrical resistance there is a temperature limit below the maximum permissible temperature of 125 ° C. Heating device according to one of claims 8 to 11, characterized in that in the event of failure of an NTC sensor (12, 13) or if a line leading to it from the microcomputer (33) breaks, the exclusion of a malfunction is ensured by a plausibility detection and both Temperature of the surface of the metal plate (11) and the temperature (9) of the water bed core are limited. Heating device according to one of claims 10 to 13, characterized in that the microcomputer (33) and the controller (6) are housed in a common housing.

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