EP2180759B1 - Electric heating device - Google Patents

Description

The invention relates to an electrical heater designed as a heating element or tubular heating element with at least one coiled, wire-shaped heating element, which is embedded in a metal jacket, for example made of steel or stainless steel in a compact Isolierstofffüllung of metal oxide, in particular magnesium oxide, embedded, wherein the heating conductor with out of the metal shell provided out guided electrical connections and switchable via at least one temperature-dependent activatable, electrical switching and / or control element.

Both cartridge heaters and tubular heaters of the generic type have been known for some time. While the metal sheath of a heating element is closed at one end by a solid bottom and usually the electrical connections are led out from the other end of the metal shell, the metal shell of a tubular heater usually consists of a tube at both ends after filling by subsequently inserted end plates is closed, wherein the electrical connections of the heat conductor are usually passed through the two end plates to the outside.

Out DE 25 13 494 C2 as well as out DE 299 20 503 U1 Heating cartridges of the generic type are known.

In general, such cartridges have such a high heating power that they can destroy themselves in the absence or non-functioning power limitation or regulation. From the cited documents heating regulations are accordingly known, which serve to prevent such an "overload". So it is from the DE 25 13 494 C2 known to use a thermal circuit breaker.

In this heating cartridge, a bimetallic switch is disposed in a tubular insulating case inserted into a terminal-side end portion in the metal jacket tube of the heating cartridge. About terminal bolts, which are used in frontal closure disks of the insulating material, the bimetallic switch is on the one hand with the Heizdrahtwicklung and on the other hand with an energy source in combination. Whether the Heizdrahtwendel this heating cartridge is embedded in a compacted Isolierstoffmasse, can not be found in the description.

In order to achieve the lowest possible time delay and the best possible response, it is from the DE 299 20 503.7 U1 known, in an electric immersion heater with a wound on a wound body wire heating conductor a temperature-dependent insert electrical switch or regulator. In this electric immersion heater sits the temperature-dependent electrical switch or regulator axially outside a Isolierstofffüllung, in which the heating element is embedded in the cavity of a second metal jacket tube. The Isolierstofffüllung is completed axially by an insulating closure element and separated by this from the axially adjacent region. This second jacket tube extends from the region of the insulating material filling in the subsequent, lying outside the Isolierstofffüllung axial region and is enclosed by the metal shell of the heating element.

This is an improved thermal connection between the region of Isolierstofffüllung and the switch or regulator and thus a timely reaction of the switch or regulator can be achieved.

However, further measures are required here, in particular to protect the switch or controller or the connections against external influences and against short circuits. Thus, in particular, this mentioned cavity for fixing the switch or regulator and / or the connections must be poured separately by means of a synthetic resin. In another variant, the temperature-dependent switch and / or regulator within the second jacket tube can also be arranged in an insulating sleeve. In any case, additional installation work is to be provided here by which in particular the manufacturing process of this known heating cartridge is made more expensive. Furthermore, the integration of a compacted heating cartridge of the generally speaking "temperature component" only possible in the end regions of this heating cartridge, so that temperature fluctuations can only be detected in these end regions. Also, such "temperature components" are usually extremely sensitive to high temperatures, so that, for example, such a temperature component in the ground area can be difficult to integrate, as a rule, the bottom of such a heating element after the introduction of the temperature component still needs to be welded, resulting in high thermal loads of the temperature component. Accordingly, an arrangement of "temperature components", for example, between two Heizleiterabschnitten is not possible in particular in highly compressed heating cartridges. However, such high-density cartridge heaters are often used, and it is here, in order to achieve a targeted temperature control, desirable to be able to arrange the "temperature component" within the heating cartridge almost arbitrarily.

In FR 2 734 686 a method for producing a heating cartridge is described, in which in an end region of the metal shell regulating and securing elements for the remaining area of the cylindrical metal shell embedded in a compressed insulating material Heizdrahtwendeln are arranged. According to this method, prior to insertion of the electrical components, the end portion provided for receiving the regulating and securing elements is reduced in diameter to a dimension corresponding to the final dimension of the diameter to which the remainder of the jacket tube is reduced during compression of the insulating material package becomes. For the accommodation of the Regulation and security elements, the cavity of a Isolierstoffhülse is provided, which is used in the pre-reduced diameter portion and separated by an insulating disc consisting of insulating material of the Heizdrahtwendeln. The control and safety elements are located outside of the insulating material, in which the Heizdrahtwendeln are embedded. The thermal connection to the heating elements is thus inadequate. This deficiency is further increased by the fact that the control and securing elements receiving cavity with a thermally insulating potting compound, eg. B. silicone, is poured out.

At the DE 299 20 503.7 U1 known heating element, the temperature-dependent devices can be connected only after filling of the metal shell with the terminals of the heating element or and used in the still open end of the metal shell. This causes a considerable costly work, which should be avoided by the inventive solution.

From the FR 2 681 496 A1 an electric heating device with the features of the preamble of claim 1 is known, the switching and / or control elements are arranged in a separated by a partition chamber of the electric heater. This brings that already in connection with the DE 299 20 503 discussed considerably costly workload with it.

From the EP 0 086 456 It is known to arrange a switching and / or control element in a separate chamber, which is formed by a connecting pipe that is closed on one side by a connecting bolt or a conical end of the connecting pipe.

Accordingly, the invention has the object, in particular in highly compressed cartridge heaters to provide an embodiment in which arranged in a simple manner a temperature-dependent activatable electrical switching and / or control or a fuse element in different axial regions as close to the heating coil can be.

This object is achieved according to the invention in a heating cartridge with the features of the preamble of claim 1, that the one or more electrical switching and / or control elements in the spatial vicinity of the heating element or but are arranged axially offset relative to these in one or more lightly or uncompacted axial portions of the Isolierstofffüllung and the metal shell.

The inventive design a heating cartridge is provided, which is extremely easy to produce. In particular, it is possible by the different densified and light or uncompressed areas of Isolierstofffüllung to arrange an electrical switching or control or more together with the one or more heat conductors in the metal jacket, after which then the Isolierstofffüllung "filled" and then can be partially compressed , A "complete" compression takes place only in the areas or sections of the metal shell in which the heating element or conductors is or are arranged. This reliably prevents the electrical switching or control element from being damaged during the compression process. On the other hand, the switching or control element can be arranged in the immediate vicinity of the heating conductor, at the same time being embedded in the insulating material filling. Thus extremely timely "switching reactions" can be achieved due to the extremely favorable heat transfer from the Heizleiterbereichen to the switching or control, so that such a designed heating element with respect to the temperature control can drive extremely precise and in particular overheating is reliably prevented. Also, a "lightweight" compaction can also be in the areas of a Switching or control element may well be allowed. However, this is not done with the "strength" in the areas or sections in which the heating conductors are arranged to safely avoid damage to the switching or controls. Ultimately, the degree of "light" compression of Isolierstofffüllung in the range of these sections depends on the switching or control elements used or their pressure resistance.

Furthermore, the switching or control elements can be integrated axially outside the heating conductor (s) in approximately any axial position in the metal shell or in the heating cartridge. So, as required, in one or each of the end regions and / or in one or more regions in between.

Further advantageous embodiments can be found in the further subclaims.

Thus, it can be provided according to claim 2, that the portion of the metal shell with light or unverdichteter Isolierstofffüllung with the one or more switching and / or control (s) is in the end of the heating cartridge, from which the electrical connections of or from a the switching and / or control elements controlled heating element are led out of the front side of the metal shell. The connections can be led out of the heating cartridge only on one side or on both sides. In a one-sided lead out of the connections, the lightly or uncompacted portion is located in only one end region of the metal shell, while with two-sided lead-out of the connections, the light or uncompressed section in both end regions the heating cartridge is arranged. Depending on requirements, however, a "single-sided" arrangement of the switching and / or control elements in only one end region can be provided independently of the lead-out of the connections.

According to claim 3 it can further be provided that the portion of the metal shell is arranged with slightly or non-sealed Isolierstofffüllung with the one or more switching and / or control elements in an axially between two sections of the metal shell with compressed Isolierstofffüllung.

According to claim 4, the one or more portions of the metal sheath with lightly or uncompacted Isolierstofffüllung can each be in a portion of the metal shell whose cross-sectional shape and / or cross-sectional size of that corresponds to a portion of the metal shell with compacted Isolierstofffüllung.

Furthermore, it can be provided according to claim 5, that the sections of the metal shell before compacting in the region of the insulating material to be compacted have a larger inside diameter than the portions of the metal shell, which contain only slightly or non-densified Isolierstofffüllung after completion. This configuration ensures that only the area to be compacted with the recorded heating conductors is "strongly" compressed during the compression process, whereby a uniform outer contour of the heating cartridge is achieved after compression.

In such heating cartridges, fasteners, e.g. mounted in the form of a mounting flange and welded or soldered to the metal shell. Since high temperatures (melting temperatures) arise during welding and soldering, which can be detrimental to control or regulating elements, it is important and advantageous if these welding or soldering operations can be carried out even before the temperature-sensitive components are inserted into the metal jacket. For this purpose, it is necessary that the portion of the metal shell to which the fastener is welded or soldered, already has its final shape. Due to the embodiment of claim 6, this advantage is perceived.

According to claim 7 may further be provided that the metal shell is closed in its the outgoing terminals axially opposite end portion by an end wall. This reliably prevents the insulating material from escaping from the heating cartridge during the compression process.

In the same way, this can also be prevented by the embodiment according to claim 8, which provides that the metal shell is closed in the end region of the led out terminals by an end wall and that the connections are passed through this end wall. In the case of a connection on both sides, such an end wall is of course provided in both end regions of the metal shell or the heating cartridge. This end wall can be removed again after compacting or pressing the metal shell and may for this purpose consist of a ceramic material or of a plastic. Should it be necessary, then the end wall can also be replaced by a filler filling, a potting compound or the like after the compression, so that the heating device is substantially "flush" closed in its respective end region.

According to claims 9 and 10 may be provided in the metal shell an additional formangepasstes metal tube, which rests against the metal shell over the entire surface both before the compression process and after the compression process. By this configuration, a greater stability of the heating element is achieved. Due to the full-surface contact between the additional metal tube and the metal shell at the same time an extremely favorable heat conduction is ensured. This additional, integrated metal tube has a very good thermal conductivity, which directs the heat, especially for example in the "drying" of a provided in a washing machine heating element very quickly in the range of the temperature sensor or the temperature switch or the temperature fuse to these temperature elements faster to bring the "response". The additional metal pipe functioning as a heat pipe can be used e.g. Made of copper or aluminum or any other suitable material with high thermal conductivity.

In this case, the jacket tube according to claim 9 axially either over the entire length of the metal shell or only over a partial area, in particular only over the compressed or the light or uncompressed portion of Isolierstofffüllung extend.

According to claim 11, it can be provided that the sections of the metal shell before compression in the region of the "strong" to be compacted Isolierstofffüllung have the same inside diameter as the portions of the metal shell, which contain after completion light or uncompressed Isolierstofffüllung and that the sections of the metal shell have after compaction in the field of "strong" to be compacted Isolierstofffüllung a smaller inner diameter than the sections of the metal shell, which contain after completion light or uncompressed Isolierstofffüllung. As a result of this embodiment, after the compacting or pressing, the heating cartridge is given a stepped outer contour, which simplifies its tight fitting.

It can further be provided according to claim 12, that the switching and / or control elements are designed as a fuse, Platinmesswiderstand, NTC, bimetal switch or a combination of these. Thus, the heating element is customizable as needed to the present "switching or monitoring tasks" in a simple manner.

Furthermore, it can be provided according to claim 13, that the switching and / or control elements and / or their electrical connections to the heating conductor or the heating conductors are guided in an insulating, the switching and / or controls leading support body in the metal tube, which passages, in particular in the form of outside recesses and / or "inner" through holes for have the Isolierstofffüllung and / or form such passages with the metal shell.

Fig. 1

einen Vertikalschnitt durch eine erste Ausführungsform einer erfindungsgemäße Heizpatrone vor dem Verdichtungsvorgang;

Fig. 2

die Heizpatrone aus Fig. 1 nach dem Verdichtungsvorgang;

Fig. 3

einen Vertikalschnitt einer zweiten Ausführungsform einer erfindungsgemäßen Heizpatrone vor dem Verdichtungsvorgang;

Fig. 4

die Heizpatrone aus Fig. 3 nach dem Verdichtungsvorgang, wobei hier zwei Teilbereiche mit Heizleitern verdichtet sind;

Fig. 5

einen Vertikalschnitt einer Ausführungsform einer Heizpatrone mit zusätzlichem Mantelrohr, welches innerhalb des Metallmantels angeordnet ist, vor dem Verdichtungsvorgang;

Fig. 6

einen Vertikalschnitt der Heizpatrone aus Fig. 5 nach dem Verdichtungsvorgang;

Fig. 7

einen Vertikalschnitt eines Ausführungsbeispiels einer Heizpatrone, bei welcher ein Schalt- und/oder Steuerelement in Form eines Platinmesswiderstandes oder NTC im Bereich der Bodenplatte angeordnet ist;

Fig. 8

einen Vertikalschnitt der Heizpatrone aus Fig. 7 nach dem Verdichtungsvorgang;

Fig. 9

eine Schnittdarstellung einer Heizpatrone im unverdichteten Zustand;

Fig. 9a

eine Draufsicht auf einen in die Heizpatrone aus Fig. 9 eingesetzten Stützkörper;

Fig. 10

eine Schnittdarstellung der Heizpatrone der Fig. 9 in verdichtetem Zustand;

Fig. 11

eine Schnittdarstellung eines Rohrheizkörpers mit zwei aus seinen Endbereichen heraus geführten Anschlüssen in unverdichtetem Zustand;

Fig. 12

eine Schnittdarstellung des Rohrheizkörpers aus Fig. 11 in verdichtetem Zustand;

Fig. 13

eine der Fig. 1 entsprechende Darstellung einer Heizpatrone mit einem Befestigungsflansch;

Fig. 14

eine Stirnansicht XIV aus Fig. 13;

Fig. 15

eine der Fig. 2 entsprechende Darstellung einer Heizpatrone mit einem Befestigungsflansch;

Reference to the drawings, the invention is explained in more detail by way of example with reference to some embodiments. The invention is not limited exclusively to the illustrated embodiments. In particular, it should be noted that the areas or sections of the insulating material below referred to as uncompressed may also be weak or slightly compacted, provided that it is ensured that the switching and / or control elements or securing elements accommodated in these sections of the metal jacket are correspondingly pressure-resistant. It shows:

Fig. 1

a vertical section through a first embodiment of a heating cartridge according to the invention before the compression process;

Fig. 2

the heating cartridge off Fig. 1 after the compaction process;

Fig. 3

a vertical section of a second embodiment of a heating cartridge according to the invention before the compression process;

Fig. 4

the heating cartridge off Fig. 3 after the compression process, here two partial areas are compressed with heating conductors;

Fig. 5

a vertical section of an embodiment of a heating cartridge with additional jacket tube, which is disposed within the metal shell, before the compression process;

Fig. 6

a vertical section of the heating cartridge Fig. 5 after the compaction process;

Fig. 7

a vertical section of an embodiment of a heating element, in which a switching and / or control element in the form of a Platinmesswiderstandes or NTC is arranged in the region of the bottom plate;

Fig. 8

a vertical section of the heating cartridge Fig. 7 after the compaction process;

Fig. 9

a sectional view of a heating cartridge in the uncompressed state;

Fig. 9a

a plan view of a in the heating cartridge Fig. 9 used supporting body;

Fig. 10

a sectional view of the heating cartridge of Fig. 9 in a compacted state;

Fig. 11

a sectional view of a tubular heater with two guided out of its end portions outlets in uncompressed state;

Fig. 12

a sectional view of the tubular heater Fig. 11 in a compacted state;

Fig. 13

one of the Fig. 1 corresponding representation of a heating cartridge with a mounting flange;

Fig. 14

a front view XIV off Fig. 13 ;

Fig. 15

one of the Fig. 2 corresponding representation of a heating cartridge with a mounting flange;

Fig. 1 shows a vertical section of an embodiment of a heating cartridge 1 according to the invention, which has a metal shell 2 consisting for example of steel or stainless steel. This metal shell 2 is closed in its one end region by means of a bottom plate 3, which is tightly connected, for example by a welded connection with the metal shell 2. Furthermore, it is off Fig. 1 recognizable that the jacket tube 2 in its bottom plate 3 axially opposite end portion 4 has a smaller cross-section or clear width than the remaining portion 5. It provides Fig. 1 the unpressed state of the metal shell 2 is.

Within the metal shell 2 an insulating material 6 is provided, in which in the region of the section 5 a coiled heating conductor 7 is embedded. This heating element 7 is wound in the present embodiment on a bobbin 8. In the region of section 4 of the jacket tube 2, the Isolierstofffüllung 6 takes in the present embodiment, two electrical or electronic switches or regulators 9 and 10. These switches or regulators 9 and 10 serve for the temperature-dependent activation of the heating conductor 7.

For this purpose, corresponding connecting lines 11 and 12 are provided between the heating conductor 7 and the switch / controller 9 or 10. Of these switches / regulators 9 and 10, two terminals 13 and 14 lead out of the metal shell 2. In the outer end region of the section 4, a further end wall 15 is provided, through which the metal shell 2 is also sealed to the outside, so that no insulating material of Isolierstofffüllung 6 can escape to the outside. The two terminals 13 and 14 are accordingly passed sealingly through this end wall 15 to the outside.

To be sure that prevents the condition of the Fig, 1 subsequent compression process, the switch or controller 9 or 10 can take damage, a compression takes place only in section 5 of the metal shell 2 by this is compressed in this area, for example, including radially. The preparation of such a heating cartridge 1 with their switches / regulators 9, 10 is extremely simple, since the heating element 7 can be used with the winding body 8 together with the switches / regulators 9 and 10 in the pre-provided with the welded bottom 3 metal shell 2 and then the filling of the heating cartridge 1 can be done with usually granulated insulating material.

Subsequently, the end wall 15 is inserted, so that the interior of the metal shell 2 is "hermetically" closed to the outside. Due to the radial compression of the portion 5 of the metal shell 2, a compression of the Isolierstofffüllung 6 takes place exclusively in this area of this section 5, so that, for example, in Fig. 2 shown final form results as a continuous smooth cylinder.

This advantageously ensures that the heating cartridge 1 according to the invention can be acted upon by a high surface load in the region of the section 5 due to the compression of the insulating material filling 6. Furthermore, the two switches / controllers 9 and 10 in the immediate Neighborhood arranged to the heating element 7, so that an optimal heat transfer, inter alia, on the non-compacted in section 4 Isolierstofffüllung 6 can take place on the switch / controller 9 and 10. This extremely low reaction times of the switches / controllers 9 and 10 can be achieved, so that the heating element 1 is optimally controlled and in particular overheating is safely excluded.

In the Fig. 13 to 15 is the same heating cartridge 1 as in the Fig. 1 and 2 shown. However, this heating cartridge is provided with a mounting flange 45 which is placed on the diameter-tapered portion 4 of the metal shell 2 and secured by a weld 46 thereto. So that the switch / controller 9 and 10 is not exposed to harmful temperatures when welding the mounting flange 45, the attachment of the mounting flange 45 takes place before inserting the heating coil 7 and the switch / regulator 9 and 10 in the metal shell 2, already with the in diameter tapered end portion 4 is provided.

It is also conceivable that such heating cartridges can be heated differently over their axial length and accordingly can have a plurality of, for example, axially successively arranged heating conductors, which in turn are separately controllable.

Such an example shows Fig. 3 as a sectional view. Here, a heating cartridge 20 is shown, which also has a metal shell 21. This metal coat 21 has in its right end region and in its central region in each case a section 22 or 23 with respect to the respective adjacent sections 24 and 27 of smaller diameter. In the lying between these two tapered sections 22 and 23 radially expanded portion 24 of the metal shell 21, two coiled heating conductors 25 and 26 are arranged. In the radially widened section 27 which adjoins the radially tapered section 23, two coiled heating conductors 28 and 29 are likewise arranged. Between the heating conductors 25, 26 and 28, 29 in turn two switches or controllers 30 and 31 are provided in the region of the radially tapered portion 23, which via corresponding connecting lines 32 and 33 and 34 and 35 with the heating conductors 28 and 29 on the one hand and the Heat conductors 25 and 26 on the other hand in conjunction.

Of the heating conductors 25 and 26, two terminals 36 and 37 led out to the outside of the metal shell 21. In the region of the right, radially tapered portion 22 of the metal shell 21, a thermocouple or a temperature sensor 38 is provided by way of example, which is connected via two connecting lines 39, which are also led out of the metal shell 21, with an electronic control unit not shown in connection. By this control unit, the entire heating cartridge 20 via the terminals 36 and 37 is additionally regulated.

Furthermore, it is off Fig. 3 can be seen that the metal shell 21 is also closed in its left end by a bottom plate 40, said bottom plate 40 may also be tightly connected, for example by a welded joint with the metal shell 21.

In the right end region of the section 22, an end wall 41 is also arranged in the heating cartridge 20, which is penetrated by the terminals 36 and 37 and the connecting lines 39 to the outside sealingly.

Next is out Fig. 3 recognizable that the cavity of the metal shell 21 is also filled with a Isolierstofffüllung 42. It is in Fig. 3 the uncompressed state of this Isolierstofffüllung 42 and the unpressed state of the metal shell 21 is shown. That is, this representation of Fig. 3 shows the unpressed state of the heating cartridge 20th

Similar to the already after the Fig. 1 and 2 described embodiment, now this heating element 20 is now radially compressed in their originally extended sections 24 and 27, so that this then forms a heating cartridge 20 with a uniform outer contour in the form of a smooth cylinder, as in Fig. 4 is shown. How out Fig. 4 can be seen, the individual sections 22, 23 and 24 and 27 after pressing the same outer dimensions (diameter), so that the heating element 20 in the in Fig. 4 illustrated embodiment has a uniform cylindrical shape over its entire length.

Besides, it is off Fig. 4 It can be seen that, after the pressing process, the insulating material filling 42 in the regions of the heating conductors 28 and 29 and the heating conductors 25 and 26 are compressed is. Since a compression of the metal shell 21 takes place only in the sections 24 and 27, the Isolierstofffüllung 42 is not pressed in the sections 22 and 23, so that in particular damage to the switches / regulators 30 and 31 and the thermocouple 38 during the pressing safely excluded is.

For the production of the heating cartridge 20, the same applies as for the production of the heating cartridge 1. That is, first in the "unpressed" metal shell 21, the heating conductors 25, 26 and 28, 29 together with the switches / controllers 30, 31 and the thermocouple 38th be used. Subsequently, the filling is carried out with a corresponding insulating material of metal oxide, in particular magnesium oxide, so that then the previously provided with the bottom plate 40 metal shell 21 can be closed by the insertion of the end wall 41. By appropriate compression of the metal shell 21 in the sections 24 and 27 of the heating cartridge 20 from Fig. 3 Then follows exclusively in these sections 24 and 27, a compression of the insulating material or Isolierstofffüllung 42nd

This manufacturing process or this manufacturing method is extremely easy to carry out even in the embodiment of the heating cartridge 20. In particular, with reference to the embodiment of the 3 and 4 It can be seen that, due to this partial or sectional compression of the insulating filling 42, a plurality of heating conductors 25 and 26 or 28 and 29 can also be controlled by electrical or electronic switches / regulators 30, 31 or temperature sensors 38 or actuated in conjunction with one another are arranged in different axial sections 22 and 23, respectively.

Fig. 5 shows yet another embodiment of the heating element 1 from Fig. 1 , Here, the same reference numerals are entered for the same elements, so that the description of the Fig. 1 and 2 Also on the drawing figures 5 and 6 is readable.

In contrast to the embodiment of the heating cartridge 1 off Fig. 1 rejects the heating cartridge 1 Fig. 5 nor an additional, inner jacket tube 50, which is applied over the entire surface fitting in the metal shell 2 of the heating element 1. This inner jacket tube 50 is adapted to the unpressed cross-sectional shape of the metal shell 2 and accordingly also forms a radially expanded portion 51 and a radially tapered portion 52. This means that here also a sole compression of the metal shell 2 in the region of section 5 also a compression of the additional jacket tube 50 causes in the section 51. Thus, here too a compression of Isolierstofffüllung 6 takes place exclusively in this section 5 and 51, so that here too a heavy-duty heating cartridge 1 is formed. This additional jacket tube 50 is made of a highly heat conductive material, such as copper, aluminum or the like., So that an extremely fast heat conduction from the areas of the heating element 7 to the switching and / or control elements 9, 10 and thus the reaction time or the Response of the heating cartridge is further improved.

In summary, it can thus be stated that here as well a heating cartridge can be produced in a very simple manner and at the same time it is also possible to arrange the temperature-regulating or -controlling elements spatially in the immediate vicinity of the heating conductors, so that optimum heat transfer, in particular through the insulating material filling 6 or 42 is reached. This is an extremely efficient temperature control / regulation of the heating element and thus the compacted heating element in many ways possible.

In the FIGS. 7 and 8 For example, a variant of a heating cartridge 1 is shown, in which a switching and / or control element is provided as a "resistance sensor" 65, for example in the form of a platinum measuring resistor or NTC. The non-pressed or only slightly compressed section 4 with the slightly or unpressed insulating material filling is in this embodiment in the region of a portion 4 of the metal shell 2, which is arranged in the end region of the bottom plate 3. In the in Fig. 7 Here, too, the section 5 of the metal jacket 2, in which the heating conductor 7 wound onto the winding body 8 is arranged, has a larger outside diameter than the section 4 in the region of the resistance sensor 65. Corresponding connection lines 66 run through this resistance sensor 65 axially opposite end wall 15 of the metal shell 2 through outward. Especially for automotive applications or other devices with an electronic control, such as tumble dryers, dishwashers or other machines, such a resistance sensor is particularly suitable because of its temperature can be detected by an electronic control over its specific resistance characteristic and thus controlled. This means that heating elements with a resistance temperature sensor can - unlike traditional thermocouples such as Fe-CuNi or NiCr-Ni, etc. - be detected and controlled by the electronic control. Furthermore, this embodiment is comparable to the embodiment of the heating cartridge Fig. 1 formed, so that the same reference numerals are also entered and the relevant description to Fig. 1 on the embodiment of the heating cartridge 1 from the FIGS. 7 and 8 to read.

In the embodiments described here, the non-compacted (or slightly compressed) remaining sections 4, 22, 23 of the metal shell 2 and 21 are provided before the compression process with a reduced cross-section or diameter, so even after compression over its entire axial length cylindrical heating cartridge is present.

But it is also readily possible and easily imaginable to use a preferably cylindrical metal shell as a starting material, which has a uniform over the entire length of cross-section and diameter before compacting. In such an initial form of the metal shell this is pressed during the pressing process "only" in the region of the sections of the heating element. This results in the region of these sections of the metal shell after the pressing process also the compressed areas of Isolierstofffüllung. Since the metal shell is pressed only in these sections, this results in a axially stepped outer contour of the heating cartridge, since the areas with the switching and / or controls containing portions of the metal shell are not or at most only slightly (= weak) pressed. This axially stepped outer contour of the metal shell may be advantageous in particular for the final assembly of such cartridge heaters. Furthermore, this type of production offers the advantage that a "conventional" cylindrical tube can be used as the starting material for the metal shell, which does not have to be preformed in advance into an "oppositely" stepped outer contour to be predetermined.

The FIGS. 9 and 10 show a vertical section through a further embodiment of a heating cartridge 1, which from the heating element 1 from the FIGS. 5 and 6 is derived. In that regard, the description is to the FIGS. 5 and 6 also on the heating cartridge 1 from the FIGS. 9 and 10 to read. Accordingly, also in the FIGS. 9 and 10 the same reference signs entered. In the embodiment of the heating cartridge 1 of FIGS. 9 and 10 is in the region of the section 4 of the metal shell 2 and 52 of the jacket tube 50, a support body 55 used. This support body 55 serves to support the two switches / controllers 9 and 10. To fill the radiator 1 after insertion of the heating element 7 together with the winding body 8 and the two switches / regulators 9, 10 together with the support body 55 with the Isolierstofffüllung 6 can, the support body 55 on the one hand a plurality of evenly distributed on its circumference arranged recesses 56. Furthermore, two receiving bores 57 and 58 are provided in the support body 55, in which the two switches / controllers 9, 10 are received with play. Between these mounting holes 57, 58 are like this Fig. 9a can be seen, two through holes 59 and 60 are provided, which also facilitate the filling of the heating element or the metal shell.

It can be seen that in the in Fig. 9 illustrated uncompacted state of the heating element 1, the uncompressed Isolierstofffüllung 6 both in the region of the section 5 as in the region of the portion 4 of the metal shell and thus in the region of the recesses 56 and the through holes 59 and 60. The play between the receiving bores 57 and 58 and the switches / regulators 9, 10 may also be selected so that after filling in the space formed also uncompressed Isolierstofffüllung 6 is.

After pressing the jacket 2 of the immersion heater 1 in the region of the section 5, the Isolierstofffüllung 6 is now compressed in this area, while in the region of the section 4 no compression of Isolierstofffüllung 6 takes place. The support body 55 provides in the illustrated embodiment according to the FIGS. 9, 9a and 10 for an "additional" guidance of the two switches / rule 9, 10, in particular also when inserting into the metal jacket 2 or into the jacket tube 50 of the heating cartridge 1.

The FIGS. 11 and 12 show a further variant of a heating device of the type according to the invention, which is designed as a tubular heater 70. This tubular heater 70 forms a metal jacket 71, which in each case has a radially tapered section 72 or 73 in its two end regions. Between these two sections 72 and 73, the metal shell forms a radially expanded portion 74, in which a heating conductor 75 is arranged. This heating conductor is wound on a bobbin 75 in the illustrated embodiment.

In the left section 72, a switch in the form of a bimetallic switch 77 is arranged in the present embodiment. In the area of the right section 73, for example, a "switching element" in the form of a fuse 78 is provided. The bimetallic switch is connected via a connecting line 79 to the heating conductor 75 in connection, while the fuse 78 is connected via a connecting line 80 to the heating conductor 75. From the bimetallic switch 77, a terminal 81 leads through an inserted into the metal shell 71 in the left end wall end wall 82 to the outside. In the right end region of the metal jacket 71, a second end wall 84 is inserted, through which a second connection 83 is led out of the metal sheath 71 from the fuse 78 to the outside.

In the in Fig. 11 shown state of Rohrheizköpers 70 are the bimetallic switch 77, the heating coil 75 together with the winding body 76 and the fuse 78 in a non-compact Isolierstofffüllung 85th

After compacting, by pressing the metal shell 71 in the region of the section 74, the Isolierstofffüllung 85 is now compressed in this area. This condensed "final state" shows Fig. 12 , It can also be seen here that in the illustrated embodiment the tubular heater 70, this having a uniform outer contour over its entire length after compression.

Again, it is conceivable that the initial state of the metal shell 71 before pressing has a uniform cylindrical outer shape. Accordingly, the metal shell 71 forms after pressing an axially stepped outer contour, which is "radially tapered 'centered. This can be particularly advantageous for the fixed assembly.

Next shows Fig. 12 in that both the bimetal switch 77 and the fuse 78 in the sections 72 and 73 are each in an uncompressed (or slightly compressed) region of the insulating filling 85, while the heating conductor 75 is in a compacted state with a winding body 76 in the section 74 of the metal jacket 71 Area is arranged. Also from the FIGS. 11 and 12 It can be seen that a tubular heater with its two-sided terminals 81 and 83 in a simple manner by section-wise pressing the metal shell 71 and thus by sections compressing the Isolierstofffüllung 85 with integrated "switches / controllers" can be produced.

Claims (12)

1. An electrical heating apparatus designed in the form of a heating cartridge (1, 20) or a tubular heating body (70) with a metal jacket (2), and an insulating material filling (6, 42, 85) of metal oxide which is arranged inside the metal jacket (2) and which is sealed in the region of a portion (5) and in which at least one coiled heating conductor (7, 25, 26, 28, 29, 75) in the form of a wire is embedded in the region of the portion (5), wherein the heating conductor (7, 25, 26, 28, 29, 75) is provided with electrical connections (13, 14, 36, 37, 81, 83) extending out of the metal jacket (2, 21, 71) and is capable of being switched by way of at least one electrical switching and/or control element (9, 10, 30, 31, 38, 77, 78) capable of being activated in a manner dependent upon temperature,
   characterized in that
   the electrical switching and/or control element(s) (9, 10, 30, 31, 38, 77, 78) is/are arranged in the spatial vicinity of the heating conductor or the heating conductors (7, 25, 26, 28, 29, 75) but axially offset from the latter in one or more only slightly compressed or not compressed axial portions (4, 22, 23, 72, 73) of the insulating material filling means (6, 42, 85) and of the metal jacket (2, 21, 71), in such a way that the insulating material filling in the region of the non-compressed portion (4, 22, 23, 72, 73) of the metal jacket (2, 21, 71) receives the electrical switching and/or control elements (9, 10, 30, 31, 38, 77, 78).
2. An electrical heating apparatus according to Claim 1, characterized in that the portion (4) of the metal jacket (2, 21, 71) with only slightly compressed or not compressed insulating material filling (6, 85) with the switching and/or control element or elements (9, 10, 77, 78) is situated in the end region of the heating apparatus (1, 20, 70), from which the electrical connections (13, 14, 36, 37, 81, 83) of the heating conductor or the heating conductors (7, 28, 29, 75) controlled by one of the switching and/or control elements (9, 10, 38, 77, 78) extend out of the front face of the metal jacket (2, 21, 71).
3. An electrical heating apparatus according to Claim 1 or 2, characterized in that the portion (23) of the metal jacket (21) with only slightly compressed or not compressed insulating material filling (42) is arranged with the switching and/or control element or elements (30, 31) in a ... axially between two portions (24, 27) of the metal jacket (21) with compressed insulating material filling (42).
4. An electrical heating apparatus according to Claim 1, characterized in that the portion or portions (4, 22, 23, 72, 73) of the metal jacket (2, 21, 71) with only slightly compressed or not compressed insulating material filling (6, 22, 23, 72, 73) are present ... of the metal jacket (2, 21, 71), the cross-sectional shape and/or cross-sectional size of which corresponds or correspond to that of a portion (5, 24, 27, 74) of the metal jacket (2, 21, 71) with compressed insulating material filling (6, 42, 85).
5. An electrical heating apparatus according to any one of Claims 1 to 4, characterized in that the portions (5, 24, 27, 74) of the metal jacket (2, 21, 71) before the compression in the region of the insulating material filling (6, 42, 85) to be highly compressed have a greater internal width than the portions (4, 22, 23, 72, 73) of the metal jacket (2, 21, 71) which after the completion contain the slightly compressed or not compressed insulating material filling (6, 42, 85).
6. An electrical heating apparatus according to any one of Claims 1 to 5, characterized in that the metal jacket (2, 21, 71) in the only slightly compressed or not compressed end portion of the connections (13, 14 or 36, 37 or 81, 83 respectively) extending out, which initially has a smaller diameter or a smaller internal width respectively than in the portion or portions to be highly compressed, is provided with a fastening flange (45) or the like welded or soldered on.
7. An electrical heating apparatus according to any one of Claims 1 to 6, characterized in that the metal jacket (2, 21, 71) in the end region of the connections (13, 14 or 36, 37 or 81, 83 respectively) extending out extend[s] through this end wall (15, 41, 82, 84).
8. An electrical heating apparatus according to any one of Claims 1 to 7, characterized in that an additional jacket tube (50), which is adapted in its shape and which rests flat against the metal jacket (82) [sic] both before the compression procedure and after the compression procedure, is provided in the metal jacket (2).
9. An electrical heating apparatus according to Claim 8, characterized in that the additional jacket tube (50) extends axially optionally over the entire length of the metal jacket (2) or only over a partial area, in particular only over the portion (4 and/or 5) of the metal jacket (2) with only slightly compressed or not compressed insulating material filling (6).
10. An electrical heating apparatus according to any one of Claims 1 to 4, characterized in that before the compression the portions (5, 24, 27, 74) of the metal jacket (2, 21, 71) in the region of the insulating material filling (6, 42, 85) to be highly compressed have the same internal width as the portions (4, 22, 23, 72, 73) of the metal jacket (2, 21, 71) which after the completion contain the slightly compressed or not compressed insulating material filling (6, 42, 85),
    and
    after the compression the portions (5, 24, 27, 74) of the metal jacket (2, 21, 71) in the region of the insulating material filling (6, 42, 85) to be highly compressed have a smaller internal width than the portions (4, 22, 23, 72, 73) of the metal jacket (2, 21, 71) which after the completion contain the only slightly compressed or not compressed insulating material filling (6, 42, 85).
11. An electrical heating apparatus according to any one of Claims 1 to 4, characterized in that the switching and/or control elements (9, 10, 30, 31, 38, 55, 77, 78) are designed in the form of a fuse, a platinum measuring resistor, an NTC, a bimetal switch or a combination thereof.
12. An electrical heating apparatus according to any one of Claims 1 to 4, characterized in that the switching and/or control elements (9, 10) and/or the electrical connections (11, 12) thereof to the heating conductor (7) or the heating conductors extend in an insulating protective body (55) conducting the switching and/or control elements - which have passages, in particular in the form of apertures (56) on the outside and/or "internal" through bores (59, 60) for the insulating material filling (85), and/or form such passages with the metal jacket (2) - in the metal tube (50).

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