Tubular electric heating device and system consisting of tubular electric heating device and object to be heated

Abstract

Tubular electric heating device (100, 200, 300) with an interior space for receiving an object to be heated (10, 10', 20, 30), with a heat-conducting body (120, 120', 220, 320) radially surrounding the interior space for receiving the object to be heated (10, 10', 20, 30), and with an electric heating element (130, 230, 330) running in a groove provided in the heat-conducting body (120, 120', 220, 320), wherein the heat-conducting body (120, 120', 220, 320) is radially penetrated by at least one heat-conducting body opening (121, 121', 221, 321) in which a fixing means (150, 151', 250, 350) is located for fixing the tubular electric heating device. (100, 200, 300) on the object to be heated (10, 10', 20, 10) is arranged by interaction of a contact section (152, 152', 252, 352) of the fixing agent (150, 150', 250, 350) with the object to be heated (10, 10', 20, 30), characterized in that the tubular electrical heating device (100, 200, 300) further - either at least in sections where a heat-conducting body opening (121, 221, 321) with a fixing agent (150, 250, 350) arranged therein is present, has an outer sheath (110, 210, 310), wherein the outer sheath (110, 210, 310) has an outer sheath opening (111, 211, 311) that allows access to the fixing agent (150, 250, 350), and wherein the cross-section of the outer sheath opening (111, 211, 311) is smaller than the cross-section of a section (151, 251, 351) of the fixing agent (150, 250, 350) facing the outer sheath (110, 210, 310), - or has a heat-conducting body opening (121') with a fixing agent (150) arranged therein, which has a section with a reduced cross-section (124') above the fixing agent (150') in which the cross-section of the heat-conducting body opening (121') is smaller than the cross-section of a section (151') of the fixing agent (150'), so that in both cases the fixing agent (150,150', 250,350) is secured in the heat-conducting body opening (121,121',221,321).

Description

[0001] Tubular electric heating devices are characterized by the fact that they can be arranged on objects to be heated, in particular by being pushed onto them, so that the object to be heated can be heated from the outside. In many cases it is desirable for the heating output to vary in the direction of extension of the tubular electric heating device, i.e. along its central tube axis. This can be achieved by providing a heat conducting body, which is usually made of metal, which is provided with a groove into which an electric heater, e.g. a tubular coil cartridge, is inserted as the actual heat source, so that the course of the groove provides sections of the electric heater of different lengths on a given section of the heat conducting body, thus providing different heating outputs.In particular, an important application for such tubular electric heaters is the use as nozzle heaters for spray nozzles, which are used, for example, for injection molding.

[0002] One problem that arises when using tubular electric heaters is the defined fixation on the object to be heated. A frequently used option is to use tensionable electric heaters, such as those known from DE 10 2013 111 303 A1 or DE 20 2011 003 451 U1. The clear interior of the tubular electric heater is designed so that its cross-section is variable and, in particular, can be reduced with a clamping device after being pushed onto the object to be heated, thus creating a flat fixation.

[0003] However, this approach requires that the tubular electric heater is penetrated by slots, which then means that the heating of the object to be heated cannot be carried out evenly in all radial directions, i.e. not in all directions perpendicular to the tube center axis of the tubular electric heater, and also makes the shape that must be given to the tubular coil cartridge and thus the groove more complicated because the former cannot simply be coiled over the slot.

[0004] Alternatively, the state of the art provides for local or punctual fixing, which in practice is achieved by radially inserting heat conducting body openings in the form of threaded holes into the heat conducting body of the tubular electric heating device, in which grub screws are arranged as fixing means.

[0005] By screwing the grub screws into the threaded holes, their ends can be pressed against the object to be heated, creating a frictional connection with the object to be heated, which secures the tubular electric heating device in position. The end section of the grub screw thus brought into contact with the object to be heated thus represents an end section for securing the tubular electric heating device to the object to be heated through the interaction of a contact section of the fixing means with the object to be heated.

[0006] However, this solution has shortcomings in terms of user-friendliness. In particular, grub screws are frequently lost; moreover, the process of loosening and securing the tubular electric heating device to the object to be heated is relatively time-consuming.

[0007] Further possibilities for fixing a tubular electric heating device to an object to be heated are disclosed in DE 10 2021 109 063 A1, JP 3 209 156 U, GB 1 584 205 A and DE 295 10 136 U1.

[0008] The object of the invention is therefore to provide a tubular electric heating device with such a local fixation or a system comprising such a heating device and an object to be heated, which are simpler and more reliable than the solutions known from the prior art.

[0009] This object is achieved by a tubular electric heating device having the features of claim 1 and a system having the features of claim 8. Advantageous developments of the invention are the subject of the respective dependent claims.

[0010] The tubular electric heating device according to the invention has an interior space for accommodating an object to be heated, a heat-conducting body that radially surrounds the interior space for accommodating the object to be heated—in most cases like a cylinder jacket—and an electric heater, in many cases a coiled tubing cartridge, that runs in a groove formed in the heat-conducting body. The heat-conducting body is penetrated radially by at least one heat-conducting body opening, in which a fixing means for fixing the tubular electric heating device to the object to be heated is arranged through the interaction of a contact portion of the fixing means with the object to be heated.

[0011] It is essential to the invention that the tubular electric heating device further - either has an outer shell, at least in sections in which a heat-conducting body opening with a fixing means arranged therein is present, wherein the outer shell has an outer shell opening which allows access to the fixing means, and wherein the cross section of the outer shell opening is smaller than the cross section of a section of the fixing means facing the outer shell - or has a heat conducting body opening with a fixing means arranged therein, which has a section with a reduced cross-section above the fixing means, i.e. further away from the tube center axis of the tubular electric heating device than the fixing means, in which the cross-section of the heat conducting body opening is smaller than the cross-section of a section of the fixing means, so that in both cases the fixing means in the heat conducting body opening is secured against falling outwards, i.e. away from the tube center axis.

[0012] This has the advantage that the risk of losing the fixing means is significantly reduced and also makes it possible to use fixing means that are arranged in a movable manner in the heat conducting body opening, which opens up the use of fixing means that allow a significantly faster change between a fixing and an open position compared to grub screws guided in threaded holes.

[0013] In a particularly simple embodiment of the invention, the heat-conducting body opening and the outer shell opening are positioned concentrically to one another and have circular cross-sections. It should be noted that, particularly for the cross-section of the heat-conducting body opening, this does not mean that the diameter of this circular cross-section must be constant. The heat-conducting body opening therefore has circular cross-sections, especially if it is designed as a stepped bore with two sections that have different diameters, which can preferably be larger, particularly for the section facing the outer shell.

[0014] This is actually a preferred embodiment, particularly in conjunction with the feature that the fixing means has a fixing means head pointing outward, i.e., away from the tube center axis of the tubular electric heating device, in particular facing the outer casing, with a larger cross-section than the cross-section of the contact section. In this embodiment, the fixing means is arranged completely captively in the heat conduction opening, with the section of the heat conduction opening with a smaller cross-section forming a stop for the fixing means head.

[0015] On the side of the fixing means head facing away from the pipe center axis, an engagement or a projection for a tool with which the fixing means is actuated can preferably be arranged.

[0016] Preferably, the fixing means can be transferred by a rotary movement from an open position into a fixing position in which the contact section is pressed into the interior of the tubular electric heating device, wherein it is particularly preferred if the rotary movement is a rotation of a maximum of 90°.

[0017] This is particularly easy to achieve if the surface of the fixing means facing the outer shell, in particular the corresponding surface of the fixing means head, is adapted to the shape of the outer shell and is in contact with it when the fixing means is in the open position. In particular, it is preferred that the outer shell has the shape of a cylindrical shell, and that the surface of the fixing means, in particular of the fixing means head, facing the outer shell has the shape of a wall section of a cylindrical shell, the outer side of which has the same geometry as the inner side of the outer shell.

[0018] If a rotational movement is initiated starting from such a geometric arrangement, the highest points of the surface of the fixing means are guided along the inside of the outer shell during the rotation and due to the curvature of the outer shell, a pressure is created on the fixing means in the direction of the tube center axis of the tubular heating device, which reaches its maximum when the connecting line of the highest points of the surface of the fixing means is perpendicular to the tube center axis of the tubular heating device, which defines the fixing position of the fixing means.

[0019] An alternative simple implementation option is that a surface of the fixing means directed outwards, i.e. radially away from the central axis, is curved and in the open position a section of the outwards directed surface of the fixing means engages in the section with reduced cross section of the heat conducting body opening, wherein the wall of the heat conducting body opening in this section is shaped such that when the fixing means is rotated the section which in the open position projects into the section with reduced cross section of the heat conducting body opening is pressed out of the section with reduced cross section of the heat conducting body opening.Such a wall shape exists, for example, if in the section with reduced cross-section of the heat conducting body opening, the cross-section of the heat conducting body opening is reduced on two sides by wall sections running parallel to the pipe center axis and projecting into the heat conducting body opening.

[0020] In a further advantageous embodiment of the electric heating device, it further comprises a thermocouple arranged on a side of the electric heating device opposite the heat-conducting body opening. In this way, the fixing of the electric heating device to the object to be heated can be used simultaneously to press the tip of the thermocouple against the object to be heated with a defined contact pressure.

[0021] The system according to the invention comprising a tubular electric heating device and an object to be heated, which is accommodated in the interior of the tubular electric heating device, is characterized in that the tubular electric heating device is an electric heating device according to the invention.

[0022] In a first advantageous development of such a system, the object to be heated has a recess, and the fixing means engages in the recess in the fixing position, thus creating a positive connection between the object to be heated and the tubular electric heating device. This additionally ensures that the electric heating device is located in a precisely defined position and in a predetermined orientation on the object to be heated.

[0023] Alternatively, the fixing means can be pressed against the object to be heated in the fixing position, so that there is a force-locking connection between the object to be heated and the tubular electrical heating device, which brings about the fixing.

[0024] The invention is explained in more detail below with reference to figures illustrating exemplary embodiments. It shows: Fig. 1a: An external view of a first system comprising a tubular electric heating device and an object to be heated, in which the fixing means is in the open position, Fig. 1b: a longitudinal section through the system Fig. 1a, Fig. 1c: a detailed enlargement from Fig. 1b, Fig. 1d: a cross-section through the system Fig. 1a, Fig. 1e: a detailed enlargement from Fig. 1d, Fig. 1f: a view of the object to be heated, Fig. 2a: an external view of the first system comprising a tubular electric heating device and the object to be heated, in which the fixing means is in the fixing position, Fig. 2b: a longitudinal section through the system Fig. 2a, Fig. 2c: a detailed enlargement from Fig. 2b, Fig. 2d: a cross-section through the system Fig. 2a, Fig. 2e: a detailed enlargement from Fig. 2d, Fig. 2f: a view of the object to be heated, Fig. 3a: an external view of a second system comprising a tubular electric heating device and an object to be heated, in which the fixing means is in the open position, Fig. 3b: a longitudinal section through the system Fig. 3a, Fig. 3c: a detailed enlargement from Fig. 3b, Fig. 3d: a cross-section through the system Fig. 3a, Fig. 3e: a detailed enlargement from Fig. 3D, Fig. 4a: an external view of the second system comprising a tubular electric heating device and the object to be heated, in which the fixing means is in the fixing position, Fig. 4b: a longitudinal section through the system Fig. 4a, Fig. 4c: a detailed enlargement from Fig. 4b, Fig. 4d: a cross-section through the system Fig. 4a, Fig. 4e: a detailed enlargement from Fig. 4d, Fig. 5a: a longitudinal section through a variant of the system from Fig. 3a and Fig. 4b, Fig. 5b: a cross-section through the variant of the system according to Fig. 5a, Fig. 6a: a first representation of the operation of the fixing mechanism of a system without outer jacket, Fig. 6b: a second illustration of the operation of the fixing mechanism of a system without outer jacket, Fig. 6c: a third representation of the operation of the fixing mechanism of a system without outer jacket, and Fig. 6d: a fourth illustration of the operation of the fixing mechanism of a system without an outer jacket.

[0025] Identical components of identical embodiments are identified below with the same reference symbols; however, to improve clarity, not all reference symbols are always shown in all figures.

[0026] The Fig. 1a to 1e show different views of a first system 1 comprising a tubular electrical heating device 100, which is designed here as a nozzle heater, and an object 10 to be heated, designed here as a nozzle, which is additionally Fig. 1f is shown alone, where it can be seen that the object 10 of the system 1 to be heated has a recess 11, which in this embodiment is designed as a circumferential groove.

[0027] One can see particularly in the Fig. 1a and Fig. 1b clearly shows that the tubular electric heating device 100 has a clear interior space with a tubular central axis R, into which the object 10 to be heated is inserted in a direction parallel to the direction of extension of the tubular electric heating device. The direction of extension itself runs parallel to the tubular central axis R, starting from its electrical connections 141, 142.

[0028] The tubular electric heating device 100 essentially has the geometry of a hollow cylinder, the cylinder axis of which is the tube center axis R. Accordingly, all connecting lines that can be seen in Fig. 1d can draw a radial direction from the tube center axis located at the center point to the outer surface of the tubular electric heating device 100.

[0029] The tubular electric heating device 100 has, as can be seen particularly well in the Fig. 1a to 1c, an outer casing 110 and a heat-conducting body 120, into which a groove is formed, into which an electric heater 130, designed as a coiled tubing cartridge with a variable pitch, is wound. Furthermore, the electrical connections 141, 142 of the electric heater 130 can be seen.

[0030] A heat-conducting body opening 121 is provided in the heat-conducting body 120, which is designed here as a stepped bore with a step 122 and thus has a circular cross-section and a section 121a with a larger cross-section facing the outer casing 110. A fixing means 150 with a fixing means head 151, in which a slot-shaped tool holder 153 is provided here, and with a contact section 152 is arranged in the heat-conducting body opening 121.

[0031] Concentric to the heat conducting body opening, an outer jacket opening 111 is provided in the outer jacket 110, the cross-section of which is also circular and smaller than the cross-section of the section of the fixing means 150 facing the outer jacket 110, which section is formed by the fixing means head 151, so that the fixing means 150 is secured in the heat conducting body opening 121. The fixing means 150 is in the heat conducting body opening 121, as can be seen particularly in the Fig. 1c and Fig. 1e, is freely displaceable between a position in which the surface of the fixing head 151 facing the outer casing 110 is in contact with the inside of the outer casing 110 and a position in which the surface of the fixing head 151 facing the step 122 is in contact therewith.

[0032] It should be noted that the Fig. 1c and Fig. 1e shown positions of the fixing means 150 can actually only be taken if a force brings the fixing means 150 into contact with the inside of the outer casing 110. However, this position was Fig. 1c and Fig. 1e was deliberately chosen because it ideally illustrates that the surface 154 of the fixing means 150 or of the fixing means head 151 facing the outer shell 110 has the shape of a wall section of a cylinder shell, the outer side of which has the same geometry as the inner side of the outer shell 110 and, in particular, is curved in the same direction as the outer shell 110.

[0033] In addition, the Fig. 1a and Fig. 1d, further heat conducting body openings 128,129 or outer jacket openings 118,119 are present, in which optionally further fixing means can be present in order to fix the tubular electric heating device 100 on the object 10 to be heated.

[0034] In the Fig. 2a to 2f is the same system 1 as in the Fig. 1a to 1f, the only difference being that the fixing means 150 is brought into the fixing position, which, as can be seen from the orientation of the tool holder 153, is achieved by a simple rotation of the fixing means 150 by 90°. As can be seen in Fig. 2c, the contact section 152 of the fixing means 150 is thereby brought into engagement with the groove 11 of the object 10 to be heated, so that a positive connection is created which fixes the tubular electric heating device 100 on the object 10 to be heated.

[0035] In Fig. 2e one can best see why the fixing means 150 is no longer displaceable in the heat conducting body opening 121: Due to the rotation of the fixing means 150 by 90°, the directions of curvature of the surface 154 of the fixing means 150 or of the fixing means head 151 facing the outer casing 110 and the inside of the outer casing 110 no longer coincide and the highest points of the fixing means 150 in the illustration are now determined by the curvature of the inside of the outer casing 110, as in the Fig. 2e is particularly clearly visible, is forced downwards, i.e. pressed into the interior of the tubular electric heating device 100, which then forces the engagement of the contact section 152 in the groove 11.

[0036] The Fig. 3a to 3e show different views of a second system 2 comprising a tubular electrical heating device 200, which is designed here as a nozzle heater by way of example, and an object 20 to be heated, designed here as a nozzle, which, in contrast to the object 10 to be heated of the first system, does not have a groove 11.

[0037] The tubular electric heating device 200 is constructed almost identically to the tubular electric heating device 100: It has a clear interior space with a tube center axis R, into which the object 20 to be heated is inserted in a direction parallel to the direction of extension of the tubular electric heating device, an outer casing 210, and a heat conducting body 220, into which a groove is formed, into which an electric heater 230, designed as a tubular coil cartridge with a variable pitch, is wound, as well as electrical connections 241, 242. The heat conducting body 220 again has a heat conducting body opening 221, which here is designed as a stepped bore with a step 222 and thus has a circular cross-section. A fixing means 250 with a fixing means head 251 with a slot-shaped tool holder 253 and with a contact section 252 is arranged in the heat conducting body opening 221.

[0038] Concentric to the heat conducting body opening, there is again an outer jacket opening 211, the cross section of which is smaller than the cross section of the section of the fixing means 250 facing the outer jacket 210, which section is formed by the fixing means head 251, so that the fixing means 250 is secured in the heat conducting body opening 221 and can be freely moved between the outer jacket 210 and the step 222 in the same way as described above.

[0039] Here again, the surface 254 of the fixing means 250 or the fixing means head 251 facing the outer casing 210 is adapted to the geometry of the inside of the outer casing 210.

[0040] In addition, the Fig. 3a and Fig. 3d, further heat conducting body openings 228,229 or outer jacket openings 218,219 are present, in which optionally further fixing means can be present in order to fix the tubular electric heating device 200 on the object 20 to be heated.

[0041] In the Fig. 4a to 4e is the same System 2 as in the Fig. 3a to 3e, the only difference being that the fixing means 250 is brought into the fixing position, which, as can be seen from the orientation of the tool holder 253, is achieved by a simple rotation of the fixing means 250 by 90°. Here, the Fig. 4c and Fig. 4e the essential difference between System 1 and System 2: How to Fig. 4c, the contact section 252 of the fixing means 250 is pressed back into the interior of the tubular electric heating device 200, but in doing so strikes the object 20 to be heated and is pressed onto it, so that a frictional connection is created which fixes the tubular electric heating device 200 on the object 20 to be heated.

[0042] In Fig. 4e it is best seen why the fixing means 250 is no longer displaceable in the heat conducting body opening 221: Due to the rotation of the fixing means 250 by 90°, the directions of curvature of the surface 254 of the fixing means 250 or of the fixing means head 251 facing the outer casing 210 and the inside of the outer casing 210 no longer coincide and the highest points of the fixing means 250 in the illustration are now determined by the curvature of the inside of the outer casing 210, as in the Fig. 4e is particularly clearly visible, which then brings about the frictional connection between the contact section 252 and the object 20 to be heated.

[0043] The Fig. 5a and 5b show a longitudinal and a cross-section through a system 3, which is a variant of the system 2 of Fig. 3a and Fig. 4b, wherein the fixing means 350 of the system 3 is brought into the fixing position.

[0044] The system 3 therefore again consists of a tubular electrical heating device 300, which is designed as a nozzle heater, and an object 30 to be heated.

[0045] The tubular electric heating device 300 again has a clear interior with a tube center axis R, into which the object 30 to be heated is inserted in a direction parallel to the direction of extension of the tubular electric heating device, an outer jacket 310 and a heat conducting body 320 with a groove and a coiled electric heater 330. However, here a thermocouple 360 ​​designed as a sheath thermocouple is coiled in an additional groove, accordingly, in addition to the electrical connections 341, 342, a connection 361 of the thermocouple 360 ​​is added. Fig. 5a and Fig. 5b the cutting line runs through the measuring point of the sheath thermocouple.

[0046] In the heat conducting body 320 there is also a heat conducting body opening 321 with a circular cross-section, designed as a stepped bore with a step 322, in which a fixing means 350 with a fixing means head 351 with a slot-shaped tool holder 353 and with a contact section 352 is arranged.

[0047] Concentric to the heat conducting body opening 321, there is again an outer shell opening 311, the cross section of which is smaller than the cross section of the section of the fixing means 350 facing the outer shell 310, which section is formed by the fixing means head 251, so that the fixing means 350 is secured in the heat conducting body opening 321 and can be freely displaced between the outer shell 310 and the step 322 in the same way as described above.

[0048] Here, too, the surface 354 of the fixing means 350 or the fixing means head 351 facing the outer sheath 310 is adapted to the geometry of the inside of the outer sheath 310; the fixing is carried out according to the same principle as in system 2, but here simultaneously results in the position of the tip of the thermocouple 360 ​​being fixed.

[0049] The Fig. Figures 6a to 6d show the structure and operation of the fixing mechanism in a system that does not have an outer jacket. Fig. 6a and Fig. 6b shows the open state and the Fig. 6c and Fig. 6d shows the state in which the fixing means fixes the tubular electric heating device to the object to be heated. Fig. The view shown in Figure 6a corresponds to that of Fig. 1c, the view of the Fig. 6b of those of Fig. 1e, the view of the Fig. 6c of those of Fig. 2c and the view of the Fig. 6d of those of Fig. 2e.

[0050] Even in the Fig. The fixing mechanism shown in Figures 6a to 6d for embodiments of the tubular electric heating device without an outer jacket includes a fixing means 150' with a fixing means head 151' with a slot-shaped tool holder 153', the surface 154' of which, directed outward, i.e., radially away from the center axis of the object 10' to be heated, is curved. This fixing means 150' is received in a heat conducting body opening 121' of the heat conducting body 120' of the tubular electric heating device, the cross-section of which is reduced inwardly, i.e., toward the object 10' to be heated, by a step 122', but also has one or more projections 123' above the outwardly directed surface 154' of the fixing means head 151'.

[0051] The projection(s) 123' are shaped in such a way that a section with a reduced cross-section 124' of the heat conducting body opening 121' is formed between them and that, in the open position, a section of the outwardly directed surface 154' of the fixing means 150' engages in the section with a reduced cross-section 124' of the heat conducting body opening 121', which can be seen particularly well in Fig. 6b recognizes.

[0052] The wall of the heat conducting body opening 121' formed by the projection(s) 123' is shaped in this section such that upon rotation of the fixing means 150', the section projecting into the section with reduced cross-section 124' of the heat conducting body opening 121' in the open position is pressed out of the section with reduced cross-section 124' of the heat conducting body opening 121', which can be seen particularly well in Fig.6c. As a consequence, the contact section 152' of the fixing means 150' is then pressed against the surface of the object 10' to be heated or into a recess 11' provided therein, so that the tubular electric heating device is fixed to the object 10' to be heated. List of reference symbols 1,2,3 system 10,10',20,30 object to be heated 11.11' deepening 100,200,300 tubular electric heater 110,210,310 outer jacket 111,211,311 Outer jacket opening 118,119,218,219 additional outer shell opening 120,120',220,320 heat sinks 121,121',221,321 Heat conducting body opening 121a,121a' Section 128,129,228,229 additional heat conducting body opening 122,122',222,322 level 123' lead 124' section with reduced cross-section 130,230,330 electric heating 141,142,241,242, 341,342 connection 150,150',250,350 Fixative 151,151',251,351 Fixative head 152,152',252,352 contact section 153,153',253,353 tool holder 154,154',254,354 surface 360 thermocouple R Pipe center axis

Claims

[1] Tubular electric heating device (100, 200, 300) with an interior space for receiving an object (10, 10', 20, 30) to be heated, with a heat conducting body (120, 120', 220, 320) which surrounds the interior space for receiving the object (10, 10', 20, 30) to be heated in the radial direction, and with an electric heater (130, 230, 330) which runs in a groove made in the heat conducting body (120, 120', 220, 320), wherein the heat conducting body (120, 120', 220, 320) is penetrated in the radial direction by at least one heat conducting body opening (121, 121', 221, 321) in which a fixing means (150, 151', 250, 350) for fixing the tubular electric heating device (100,200,300) is arranged on the object to be heated (10,10', 20,10) by interaction of a contact portion (152,152',252,352) of the fixing means (150,150',250,350) with the object to be heated (10,10',20,30), characterized by that the tubular electric heating device (100,200,300) further - either at least in sections in which a heat-conducting body opening (121, 221, 321) with a fixing means (150, 250, 350) arranged therein is present, an outer jacket (110, 210, 310), wherein the outer jacket (110, 210, 310) has an outer jacket opening (111, 211, 311) which allows access to the fixing means (150, 250, 350), and wherein the cross section of the outer jacket opening (111, 211, 311) is smaller than the cross section of a section (151, 251, 351) of the fixing means (150, 250, 350) facing the outer jacket (110, 210, 310), - or a heat conducting body opening (121') with a fixing means (150) arranged therein, which has a section with a reduced cross-section (124') above the fixing means (150'), in which the cross-section of the heat conducting body opening (121') is smaller than the cross-section of a section (151') of the fixing means (150'), so that in both cases the fixing means (150, 150', 250, 350) is secured in the heat conducting body opening (121, 121', 221, 321). [2] Tubular electric heating device (100,200,300) according to claim 1, characterized by that the heat conducting body opening (121,221,321) and the outer jacket opening (111,211,311) are concentric and have circular cross-sections. [3] Tubular electric heating device (100, 200, 300) according to claim 1 or 2, characterized bythat the heat conducting body opening (121,221,321) is designed as a stepped bore and that the fixing means (150,250,350) has an outwardly facing fixing means head (151,251,351) facing the outer casing (110, 210,310). [4] Tubular electric heating device (100, 200, 300) according to one of claims 1 to 3, characterized by that the fixing means (150,150',250,350) can be transferred by a rotary movement from an open position into a fixing position in which the contact section (151,151',251,351) is pressed into the interior of the tubular electrical heating device (100,200,300). [5] Tubular electric heating device (100, 200, 300) according to one of claims 1 to 4, characterized by that the rotational movement is a rotation of a maximum of 90°. [6] Tubular electric heating device (100, 200, 300) according to one of claims 3 to 5, characterized bythat the outwardly facing surface (154,254,354) of the fixing means (150,250,350) facing the outer casing (110,210,310) is adapted to the shape of the outer casing (110,210,310) when the fixing means (150,250,350) is in the open position. [7] Tubular electric heating device (100,200,300) according to claim 6, characterized by that the outer shell (110,210,310) has the shape of a cylindrical shell and that the outwardly facing surface (154,254,354) of the fixing means (150,250,350) facing the outer shell (110,210,310) has the shape of a wall section of a cylindrical shell, the outer side of which has the same geometry as the inner side of the outer shell (110,210,310) of the tubular electric heating device (100,200,300). [8] Tubular electric heating device (100, 200, 300) according to claim 4 or 5, characterized bythat an outwardly directed surface (154') of the fixing means (150') is curved and, in the open position, a portion of the outwardly directed surface (154') of the fixing means (150') engages in the portion with reduced cross-section (123') of the heat conducting body opening (121'). [9] Electric heating device (100,200,300) according to one of claims 1 to 8, characterized by that the electric heating device (100,200,300) further comprises a thermocouple (360) which is arranged on a side of the electric heating device (100,200,300) opposite the heat conducting body opening (121,121',221,321). [10] System (1,2,3) comprising a tubular electric heating device (100,200,300) and an object to be heated (10,10',20,30) which is accommodated in the interior of the tubular electric heating device (100,200,300), characterized bythat the tubular electric heating device (100,200,300) is a tubular electric heating device (100,200,300) according to one of claims 1 to 9. [11] System (1,2,3) according to claim 10, characterized by that the object to be heated (10, 10', 20, 30) has a recess (11, 11') and that the fixing means (150, 151', 250, 350) engages in the recess (11, 11') in the fixing position, so that there is a positive connection between the object to be heated (10, 10', 20, 30) and the tubular electrical heating device (100, 200, 300). [12] System (1,2,3) according to claim 10, characterized by that the fixing means (150,150',250,350) is pressed against the object to be heated (10,20,30) in the fixing position, so that there is a force-locking connection between the object to be heated (10,20,30) and the tubular electric heating device (100,200,300).

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