EP3668272A1 - Holding body, heating apparatus and method - Google Patents

Abstract

The invention relates to a holding body for heating elements (10), in particular oval and round heating elements (10), with an outer part assembly (11) and an inner part assembly (12), which is arranged inside the outer part assembly (11) and with the outer part assembly (11) forms an elastic connection which is under mechanical tension, the outer part assembly (11) and / or the inner part assembly (12) having / having a plurality of receptacles (13) arranged distributed in the circumferential direction, in which A heating element (10) is arranged in each case, and the outer part assembly (11) and the inner part assembly (12) each have a polygon profile (14, 14 ') with polygon corners (14a, 14a') and polygon sides (14b, 14b ') which connect the polygon corners (14a, 14a '). The invention is characterized in that the inner part assembly (12) and the outer part assembly (11) can be rotated relative to one another and are dimensioned such that a relative rotation between the inner part assembly (12) and the outer part assembly (11 ) the polygonal profiles (14, 14 ') deform elastically in such a way that a press fit in the area of the heating elements (10) is formed by the induced mechanical tension in the assembled state.

Description

The invention relates to a holding body for heating elements with the features of the preamble of claim 1. The invention further relates to a heater and a method for mounting the holding body.

A holding body of the type mentioned is, for example, from WO 2013/060645 A1 known.

The constant change of day and night temperature as well as permanently extreme climatic conditions can be problematic for the electronics in systems and control cabinets. They cause condensation or frost, which can lead to corrosion. Corrosion increases the risk of malfunctions and operational failures due to leakage currents or flashovers. In order to prevent the formation of condensation and frost, to ensure proper functioning and to increase the lifespan of the electronics, constant climatic conditions are essential. Heaters or fan heaters are used for this purpose.

Such heaters are usually equipped with electrical heating elements based on PTC semiconductor technology. The holders of such heating elements must have good heat transfer on the one hand and on the other hand ensure a secure fixation. Frequent temperature changes can lead to material fatigue and thus to a reduction in the holding force for the heating elements. If the bracket fails completely, the device may fail completely.

An example of such a heater with a PTC heating element is in DE 10 2006 018 151 A1 described. Here the heating element is arranged in a centrally arranged recess of a heat exchanger. The heating element lies flat against the inner surfaces of the recess. The heating element is held in position in that the ends of the side walls of the heat exchanger are bent inwards during assembly by using pressing tools. As a result, the inner surfaces lie so close to the heating element that the heating element is clamped flat.

The buckling of the side walls, however, represents a plastic deformation of the material, which, in combination with frequent temperature changes, impairs the holding function. It is not possible to replace the heating element due to the type of assembly that permanently plastically deforms the side walls.

WO 2013/060645 A1 describes a holding body which comprises an outer part and an inner part arranged in the outer part. The outer part and the inner part are designed as polygon profiles with polygon corners and polygon sides which are connected to the polygon corners. Between the inner part and the outer part, a plurality of receiving regions are formed in the circumferential direction, in which the heating elements are arranged. The recording areas are arranged in the corners of the polygon profiles. When assembled, the sides of the polygonal profile are elastically deformed and are under mechanical tension. The resulting contact pressure acts on the heating elements and keeps them in position. The holding function is possible without additional clamping elements.

For the assembly of the holding body described above, the diameter of the outer part is first increased. The outer part diameter is increased by heating and / or by applying a force acting radially outwards or inwards. Then the inner part is inserted so that the heating elements are arranged in the receiving areas. Is the inner part in position, the outer part is cooled again and / or relieved, so that the outer part shrinks onto the inner part. As a result, the polygon sides deform elastically and build up a mechanical tension that applies and fixes the heating elements with a pressing force.

The assembly step of changing the diameter of the outer part, which is necessary to fix the inner part and the heating elements within the outer part, is time-consuming and costly.

The invention is therefore based on the object of improving a holding body of the type mentioned at the outset such that a secure mounting of the heating elements in the holding body is possible despite frequent temperature changes and cooling of the heating device, the holding body being designed such that simple assembly, in particular an easier joining of the polygon profiles is possible. Furthermore, the invention is based on the object of specifying a heater with such a holding body and a method for mounting such a holding body.

• den Haltekörper durch den Gegenstand des Anspruchs 1,
• das Heizgerät durch den Gegenstand des Anspruchs 21,
• und das Verfahren durch den Gegenstand des Anspruchs 22

gelöst.According to the invention, the task is directed towards

• the holding body by the subject matter of claim 1,
• the heater by the subject matter of claim 21,
• and the method by the subject matter of claim 22

solved.

Specifically, the task is carried out by a holding body for heating elements, in particular oval and round heating elements, with an outer part assembly and an inner part assembly which is arranged within the outer part assembly and forms an elastic connection which is under mechanical tension with the outer part assembly , solved. The outer part assembly and / or the inner part assembly have a plurality of receptacles arranged distributed in the circumferential direction, in each of which a heating element is arranged. The outer part assembly and the inner part assembly each comprise a polygon profile with polygon corners and polygon sides that connect the polygon corners to one another. The inner part assembly and the outer part assembly are rotatable relative to each other and dimensioned such that by a Relative rotation between the inner part assembly and the outer part assembly, the polygonal profiles deform elastically in such a way that a press fit in the area of the heating elements is formed in the assembled state by the induced mechanical tension, in particular by a spring force.

The press fit according to the invention is present when the largest dimension of the inner radial extent of the outer part assembly is smaller than the smallest dimension of the outer radial extent of the inner part assembly. The radial expansion relates to all components that are assigned to the respective assembly. With press fits, an assembly force is required to create a non-positive connection. The assembly force is initiated by the relative rotation.

The radial dimensions of the inner part assembly and the outer part assembly of the holding body according to the invention are accordingly dimensioned such that they overlap in the area of the receptacles for the heating elements. As a result, the inner part assembly can be inserted into the outer part assembly such that a relative rotation between the assemblies is possible. The relative rotation and the geometry of the polygon profiles create contact between the two assemblies. The inner part assembly presses the outer part assembly, in particular the polygon profile of the outer part assembly, radially outward in the regions of the receptacles for the heating elements, as a result of which the polygon profiles deform elastically. Similarly, the inner part assembly in the areas of the receptacles is pressed inwards and thereby elastically deformed. The rotation continues, whereby the polygonal profiles continue to deform elastically until the heating elements are in the intended receptacles. The elastic deformation is retained. The mechanical tension or spring force induced by the elastic deformation in the polygon profiles, that is to say in the polygon profiles of the outer part assembly and the inner part assembly, acts on the heating elements with a pressing force and fixes them in their respective receptacles. The continuous pressure is maintained even during the heating phase and ensures optimal heat transfer and fixation. In particular, the joining of the heating elements and the polygon profiles by the rotation and the close connection formed therefrom improves the heat transfer of the heating device.

The heating elements are preferably each arranged in an edge area within the holding body. This is advantageous since the air flow that flows through the holding body during operation is more concentrated in the edge regions. It is therefore particularly advantageous to arrange the heating elements in this area in order to improve the heat transfer.

A holding body according to the invention enables assembly without having to change the diameter of the outer part in an additional assembly step. The mounting of the holding body can be done almost without tools and is associated with less work and time.

The holding body for heating elements according to the invention is not only limited to use in a control cabinet. Applications in other areas are not excluded.

Preferred embodiments of the invention are specified in the subclaims.

In one embodiment, the heating elements are arranged in the assembled state between the polygon sides and / or the polygon corners. This enables different variations of the holding body. For example, a holding body is conceivable in which the heating elements are arranged exclusively in the polygon corners. Designs in which the heating elements are arranged between the polygon sides of the inner part assembly and the polygon corners of the outer part assembly or vice versa are also possible.

In a preferred embodiment, the receptacles each have wall sections which are adapted to the heating elements and at least partially surround them circumferentially. The greater and closer the contact between the polygon profiles or the receptacles and the heating elements, the better the heat transfer between the components mentioned.

In a particularly preferred embodiment, the wall sections of a receptacle are each partially formed by the outer part assembly and the inner part assembly. A first wall section has a curvature angle of K> 180 ° and a second wall section has one Angle of curvature from K <180 °. This has the advantage that the heating elements are almost completely enclosed by the wall sections, which results in better transfer of the heat and the pressing force.

In a further preferred embodiment, the outer part assembly forms the receptacles and the inner part assembly supports for the heating elements or vice versa. When installed, the heating elements are pressed against the abutment. This results in a better transfer of the contact pressure and the heat. The holding function of the receptacles is sufficient to hold the heating elements for assembly. In the assembled state, the receptacles interact with the heating elements and the abutments and form an interference fit that fixes the heating elements in a force-fitting and form-fitting manner between the inner part assembly and the outer part assembly. The receptacles for the heating elements are advantageously arranged in such a way that the polygon sides have maximum elasticity and keep the heating elements continuously under tension.

In order to bring the heating elements into a suitable position before assembly, a contact surface is arranged in front of the abutments in the direction of the relative rotation. This simplifies the assembly of the inner part assembly and protects the heating elements during assembly. During the relative rotation, the heating elements remain in contact with the polygon profile of the outer part assembly. The heating elements rub against the polygon profile. Since the contact surfaces are arranged directly in front of the abutments, the relative rotation is limited and the stress on the heating elements due to rubbing is minimized.

In order to keep the heating elements in the appropriate position before assembly, the contact surfaces can be designed obliquely or concave. The contact surfaces can be designed such that they support the transfer of the heating elements into the receptacles during the relative rotation, i.e. less resistance due to friction. Alternatively, the contact surfaces can have other shapes that are advantageous for assembly.

In a preferred embodiment, a core is arranged concentrically in the inner part assembly and connected to the inner part assembly by webs. The webs are preferably spaced as far as possible from the receptacles of the heating elements. This has an advantageous effect on the elastic deformability of the Polygon profiles and the resulting mechanical tension or spring force that holds the heating elements in place. The core has an advantageous effect on the heat dissipation and the stability (honeycomb) of the holding body. If the receptacles are formed on the polygon sides, the webs are connected to the inner sides of the polygon corners. If the receptacles are formed on the polygon corners, the webs are connected to the polygon sides of the polygon profile of the inner part assembly. In this way, a greater elastic deformation or a greater contact force can be generated in the area of the receptacles. It is conceivable that the core is connected to the polygon profile in a different way.

In a further preferred embodiment, the core forms an inner profile for receiving a tool. The relative rotation is initiated via the inner profile. Different tools are possible. The type of tool depends on the shape of the inner profile, i.e. other tools are conceivable. Alternatively, the holding body can be designed such that the relative rotation can be initiated without a tool, in particular by hand.

In a particularly preferred embodiment, the inner profile of the core is designed as an internal hexagon. This has the advantage that the relative rotation can be initiated with a hex key. The hexagon wrench is a standardized tool that is available in different sizes. This facilitates the implementation of different sizes of the inner profile and the holding body, since no special tool has to be made. Furthermore, the hexagon shape (honeycomb) results in increased stability and better frictional connection between the assemblies.

It is advantageous if a control unit is arranged on the core, in particular within the inner profile, which comprises a temperature controller or a temperature monitor and a temperature fuse, which are connected to the heating elements via a star connection. This makes it easy to install the electronic components. Alternatively, further electronic components and options for attaching the control unit are conceivable. E.g. it is conceivable that two bimetal controllers or a bimetal controller and a protective fuse are arranged on the heater and regulate the temperature of the heater or switch off in the event of overheating.

The polygon profiles comprise at least three polygon corners and three polygon sides. Versions with more sides and corners, which can have more receptacles and heating elements, are therefore possible.

The adjacent polygon corners of the polygon profiles advantageously each have the same distance angle. The symmetrical cross-section allows even cooling during the manufacturing process. The symmetry and the similar structure of the two polygon profiles allow the polygon profiles to be plugged into one another without the radial dimensions overlapping.

It is advantageous if, in the assembled state, the polygon corners of the polygon profiles are offset from one another in such a way that the polygon corners are aligned at least approximately centrally to the polygon sides arranged opposite. This arrangement favors a uniform distribution of stress and thus a uniform distribution of the contact pressure. This determines the balance of power and the system is not under- or over-determined. Further advantageously, the offset arrangement of polygon corners and polygon sides forms air channels which enable more efficient cooling or heat transport.

For the same purpose, the polygon corners of the polygon profiles can be aligned approximately the same.

Advantageously, the polygon profiles are concave, convex or straight. Such a design of the polygon profiles causes a higher mechanical tension, which improves the interference fit between the inner part assembly and the outer part assembly. Other suitable geometric shapes of the profiles are also conceivable, which bring about a higher mechanical tension of the polygon profiles and improve the holding function.

The polygon profiles can have a rib structure or a lamella structure. The resulting enlargement of the surface improves the heat exchange with the surroundings. Almost all surfaces of the holding body are suitable for having a rib structure. The inner surfaces of the mounts and the abutments are adapted to the heating elements. they lie flat against the heating elements and largely enclose them. This enables good heat transfer between the heating elements and the polygon profiles. In principle, other structures for enlarging the surface are also conceivable. Alternatively, the surface structures can be manufactured separately and joined to the surfaces of the holding body or connected in other ways. This enables more complicated rib structures and better surfaces.

It is advantageous for the assembly if the inner part assembly and the outer part assembly are arranged concentrically. A concentric arrangement of the assemblies results in an even distribution of tension in the assembled state in the polygon profiles and centers the two assemblies.

It is preferable to make the heating elements cylindrical or oval-cylindrical. Heating elements with round or at least partially round outer surfaces do not tilt during the relative rotation. Alternatively, heating elements with other shapes are conceivable.

The outer part assembly can be composed of several parts and closed with plates, in particular aluminum plates. This allows a higher surface structure to be achieved during manufacture.

In the context of the invention, a heater with a holding body is disclosed and claimed. An axial end of the holding body is connected to a fan in such a way that air can flow through the holding body in the longitudinal direction.

Within the scope of the invention, a method for assembling a holding body according to the invention according to claim 1 is disclosed and claimed. The heating elements are arranged in the associated receptacles. The inner part assembly is then inserted into the outer part assembly and rotated with a tool that interacts with the core until the heating elements are fixed between the inner part assembly and the outer part assembly by the mechanical tension induced by the elastic deformation of the polygon profiles are.

The invention is explained in more detail using several exemplary embodiments with reference to the attached schematic drawings.

Fig. 1

eine perspektivische Ansicht eines erfindungsgemäßen Ausführungsbeispiels eines Haltekörpers

Fig. 2

eine Draufsicht des Haltekörpers nach Fig. 1

Fig. 3

eine perspektivische Ansicht eines weiteren erfindungsgemäßen Ausführungsbeispiels eines Haltekörpers

Fig. 4

eine Draufsicht des Haltekörpers nach Fig. 3

Fig. 5

eine perspektivische Ansicht eines weiteren erfindungsgemäßen Ausführungsbeispiels eines Haltekörpers

Fig. 6

eine Draufsicht des Haltekörpers nach Fig. 5

Fig. 7

ein schematisches Schaltbild eines Ausführungsbeispiels

Fig. 8

einen Schnitt eines erfindungsgemäßen Ausführungsbeispiels eines Heizgeräts

Show:

Fig. 1

a perspective view of an embodiment of a holding body according to the invention

Fig. 2

a plan view of the holding body after Fig. 1

Fig. 3

a perspective view of a further embodiment of a holding body according to the invention

Fig. 4

a plan view of the holding body after Fig. 3

Fig. 5

a perspective view of a further embodiment of a holding body according to the invention

Fig. 6

a plan view of the holding body after Fig. 5

Fig. 7

a schematic diagram of an embodiment

Fig. 8

a section of an embodiment of a heater according to the invention

1 and 2 show an inventive embodiment of a holding body. The holding body comprises an outer part assembly 11 and an inner part assembly 12, which is arranged concentrically in the outer part assembly and heating elements 10 arranged between the inner part assembly 12 and the outer part assembly 11. The holding body is preferably made of aluminum and fulfills, on the one hand a holding function and another a cooling function.

The outer part assembly 11 comprises a first or an outer polygon profile 14. The inner part assembly 12 comprises a second or an inner polygon profile 14 '. The first and second polygon profiles 14, 14 'each comprise three first and second polygon corners 14a, 14a 'and three first and second polygon sides 14b, 14b'. Variants and shapes with more than three first and second polygon corners 14a, 14a 'and polygon sides 14b, 14b' are also conceivable. The number of the first polygon corners corresponds to the number of the second polygon corners 14a '. The first polygon corners 14a are flattened and have a concave curvature. The first and second polygon sides 14b, 14b 'have a convex curvature. It is conceivable that the first polygon corners 14a have a concave curvature and the first and second polygon sides 14b, 14b 'have a convex curvature. The second polygon corners 14a 'are rounded. It is possible that the first and second polygon corners 14a, 14a 'and / or the first and second polygon sides 14b, 14b' are straight.

The outer part assembly 11 comprises a spacer frame 23 which encloses the first polygon profile 14. The spacer frame 23 is designed as a square. Alternatively, other shapes are possible (e.g. round). The spacer frame 23 can also be designed as a housing. The corners of the spacer frame 23 are rounded and each have a geometrically defined attachment point 24 on their inner sides. The attachment points 24 are formed as recesses over the entire axial length of the spacer frame 23. Other forms of fastening points 24, for example those that do not extend at all or only partially or in sections over the axial length of the spacer frame 23, are conceivable. By means of the fastening points 24, the holding body can be fixed in a control cabinet and / or a fan or a cover can be arranged on the holding body. It is conceivable to connect two or more holding bodies to one another by means of the fastening points 24. A web 19 is formed on each inside of the spacer frame 23, which connects the spacer frame 23 to the first polygon profile 14. The spacer frame 23 can also be connected to the first polygon profile 14 in other ways. The spacer frame 23 and the first polygon profile 14 are preferably connected to webs 19 and formed as one component. The webs 19 are advantageously spaced as far as possible from the receptacles for the heating elements 10 in order to achieve a better spring effect and to obtain the most concentrated possible air flow in the area of the heating elements 10. Alternatively, the spacer frame 23 can be manufactured as a separate component.

The first polygon profile 14 has a lamella or rib structure on the outer and inner surfaces of the first polygon sides 14b and on the outer surfaces of the first polygon corners 14a. The rib structure increases the surface of the first polygon profile 14 and enables a more efficient heat exchange with the surroundings. Other structures that increase the surface area are also suitable. The inner surfaces of the first polygon corners 14a and the inner surfaces of the receptacles 13 have no rib structure. The inner surfaces of the first polygon corners 14a form abutments 16 and interact with the receptacles 13. The surfaces of the abutments 16 and the receptacles 13 are adapted to the surfaces of the heating elements 10 for efficient heat transfer.

The abutments 16 form part of a press fit and have a convex area in the center, against which the heating elements 10 arranged on the inner part assembly 12 rest in the assembled state. The convex area reduces the gap between the heating elements 10 and the first polygon profile 14 and thus enables better heat transfer between the two assemblies. The abutments 16 can be shaped differently for better fixation. For example, the abutments 16 can be shaped such that they partially enclose the heating elements.

The inner part assembly comprises the second polygon profile 14 ', the heating elements 10 and a core 18. Receptacles 13 are formed centrally on the outer surfaces of the second polygon sides 14b'.

The receptacles 13 are each formed from two radially outwardly directed wall sections 15. The inner surfaces of the receptacles 13 are adapted to the outer surfaces of the heating elements 10. The heating elements 10 are cylindrical and extend approximately over the entire axial length of the holding body. Other heating elements 10, in particular oval-cylindrical heating elements 10 and those with other lengths, are conceivable. The wall sections 15 do not completely enclose the heating elements 10, but in such a way that the heating elements 10 are positively fixed radially outward and are movable in the longitudinal direction. The two wall sections 15 of the receptacles 13 accordingly have an angle of curvature with K> 180 °. In each case a section of the outer surfaces of the heating elements 10, which to the inner surfaces of the first polygonal profile 14 is oriented, is not enclosed by the receptacles 13. In the assembled state, these sections interact with the abutments 16 and form the interference fit between the inner part assembly 12 and the outer part assembly 11. In addition, the sections of the heating elements 10 which are not enclosed by the receptacles 13 have the function of heat to the outer part assembly 11 to transfer.

The core 18 is arranged concentrically within the second polygon profile 14 '. The core 18 is connected by webs 19 to the inside of the second polygon corners 14a '. As a result, the second polygon sides 14b 'can build up a higher mechanical stress. The core 18 has an inner profile. The inner profile is designed as a hexagon. Alternatively, other geometries of the inner profile are conceivable. The inner profile of the core 18 interacts with a tool, in particular with a hexagon wrench, during assembly. The type and size of the tool depends on the shape of the inner profile. An initiation of the relative movement is therefore conceivable with other tools or by hand. An attachment point 24 is arranged on each of two webs 19 of the core 18. The structural features of the fastening points 24 correspond to those which are arranged on the spacer frame 23. The attachment points 24 can be arranged at other positions.

A control unit 20 is arranged at the fastening points 24 by means of a screw connection. Other types of connection, for example brackets or locking hooks, are possible for fixation. The control unit 20 comprises a temperature controller or a temperature monitor 21 and a temperature fuse 22. It is conceivable that the control unit 20 includes other or additional components. The components of the control unit 20 are as in FIG Fig. 7 schematically shown, electrically connected to the heating elements 10 via a star connection. Alternatively, other types of circuit are possible. The temperature controller or the temperature monitor 21 has the function of keeping the temperature approximately constant. The temperature can be recorded or controlled by thermistors, thermocouples or bimetal temperature switches. Other methods can be used. In the event of a defect or failure of the temperature controller or the temperature monitor 21 and simultaneous occurrence of high temperatures, the temperature fuse 22 is triggered. The temperature fuse 22 comprises an electrical connection, that melts at a certain limit temperature. If this limit temperature is exceeded, the temperature fuse 22 interrupts the electrical circuit and switches the heater off in order to avoid damage. If the temperature fuse 22 has been triggered, the heater is only ready for use again after a new temperature fuse 22 has been inserted.

The second polygon profile 14 'has a rib or lamella structure on the inner surfaces and on the outer surfaces of the second polygon corners 14a' and polygon sides 14b '. The webs 19, which connect the polygon profile 14 'to the core 18, also have a rib structure. No rib structure is formed on the inner surfaces of the receptacles 13, since as close and flat a contact as possible between the receptacles 13 and the heating elements is necessary in order to enable good heat transfer. In general, all surfaces of the holding body that are not in direct contact with the heating elements 10 can have a lamella structure, a rib structure or alternatively another structure.

The radial dimensions of the outer diameter of the inner part assembly 12 and the inner diameter of the outer part assembly 11 of the holding body are dimensioned such that they preferably overlap in the areas of the receptacles 13 for the heating elements 10, so that in the areas of the receptacles 13 in each case an excess is formed. Before assembly, the inner part assembly 12 is arranged in the outer part assembly 11 such that the oversized areas of the outer part assembly 11 and the inner part assembly 12 are offset from one another. A relative rotation is initiated by a tool, in particular a hexagon wrench, which interacts with the core 18. Other tools adapted to the core 18 are also conceivable for initiating the relative rotation.

By initiating the relative rotation, the areas of the inner part assembly 12 and the outer part assembly 11 overlap. This enables a press fit between the two assemblies, which fixes the inner part assembly 12 in the outer part assembly 11. The relative rotation initially creates contact between the two assemblies in the oversized areas. More precisely, there is contact between the heating elements 10 and the outer part or inner part assembly 11, 12. The Inner part assembly 12 presses the outer part assembly 11, in particular the first polygon profile 14 of the outer part assembly 11, radially outward in the area of the receptacles 13 for the heating elements 10, as a result of which the first and second polygon profiles 14, 14 ′ deform elastically. The relative rotation continues until the heating elements 10 are arranged in the receptacles 13 provided. The first and second polygon profiles 14, 14 'remain elastically deformed after the relative rotation.

The mechanical tension or spring force induced by the elastic deformation in the first and second polygon profiles 14, 14 'acts on the heating elements 10 with a pressing force. The convex shape of the first polygon corners 14a and the concave shape of the second polygon sides 14b 'support the opposite mechanical stresses in the first and second polygon profiles 14, 14'. The heating elements 10 are positively and non-positively fixed in the receptacles 13 in such a way that temperature changes have a minor influence on the contact pressure.

3 and 4 show a further embodiment of a holding body according to the invention.

The spacer frame 23 is in the Figures 1 and 2 described distance frame 23 identical.

In this exemplary embodiment, no surface of the holding body has a rib or lamella structure. In principle, however, all surfaces of the holding body that are not in direct contact with the heating elements 10 are suitable in order to have a rib structure or another surface structure. It is therefore also conceivable that the spacer frame 23 has a rib or lamella structure.

With regard to their geometry, the first polygon profiles 14, 14 'essentially correspond to the first and second polygon profiles 14, 14' of the exemplary embodiment according to FIGS Figures 1 and 2 . The differences are discussed in more detail in the explanations below.

In contrast to the embodiment of the Figures 1 and 2 , The recordings 13 of the in the Figures 3 and 4 Holding body shown is not formed on the inner part assembly 12, but on the outer part assembly 11. More precisely, the recordings are on the inner surface of the first polygon corners 14a of the first polygon profile 14th

The wall sections 15 of the receptacles 13 extend radially inwards. The inner and outer surfaces of the wall sections 15 are curved. The angle of curvature of the wall sections 15 is K> 180 °. More than half of the circumference of the heating elements 10 is enclosed by the wall sections 15 of the receptacles 13. The angle of curvature is selected such that the heating element 10 arranged in the receptacle 13 can only be moved in the longitudinal axis of the holding body. Different shaped heating elements 10 and accordingly different shaped receptacles 13 are conceivable. The heating elements 10 are not completely enclosed by the wall sections 15 of the receptacles 13. The radially outermost section of the heating elements 10, starting from the center of the holding body, remains free. The remaining section of the heating elements 10 interacts with abutments 16 and forms the interference fit between the inner part assembly 12 and the outer part assembly 11.

The abutments 16 are arranged on the inner part assembly 12. More specifically, the abutments 16 are formed on the outer surfaces of the second polygon sides 14b 'of the second polygon profile 14'. The abutments 16 are adapted to the heating elements 10 and partially enclose the heating elements 10. For this purpose, the abutment 16 has an angle of curvature of K <180 °. The sum of the angles of curvature of the wall sections 15 and the abutments 16 is preferably approximately 360 °. The heating elements 10 are thus almost completely enclosed by the receptacles 13 and the abutments 16 and have an almost optimal heat transfer from the heating elements 10 to the first and second polygon profiles 14, 14 '.

The relative rotation of the inner part assembly 12, in which the inner part assembly 12 and the outer part assembly 11 are positively and non-positively connected, takes place in the exemplary embodiment according to FIGS Figures 3 and 4 anti-clockwise by design. A variant in which the assembly is carried out by turning clockwise is also conceivable.

A contact surface 17 is arranged in front of the abutment 16 in the direction of the relative rotation. The contact surface 17 is formed as a concave curvature in the second polygon side 14b 'of the second polygon profile 14'. In principle, other shapes for the contact surfaces 17 are also conceivable. The heating elements 10 are arranged on the contact surfaces 17 before the relative rotation, when the inner part assembly 12 is inserted into the outer part assembly 11, in order to bring the two assemblies into a suitable position for the relative rotation. Since the contact surfaces 17 are arranged directly in front of the abutments 16, only a small rotary movement or a small angle of rotation is necessary in order to fix the heating elements 10. This prevents the heating elements 10 from rubbing and being damaged over the second polygon profile 14 ′ during the relative rotation.

The core 18 essentially corresponds to the core 18 of FIGS Figures 1 and 2 example shown. The differences are explained in more detail below.

The one in the Figures 3 and 4 The core 18 shown does not include any attachment points 24. The control unit 20 has a groove for a snap ring. By means of the snap ring, the control unit 20 can be arranged in a holder 25 and clamped together with the holder 25 in the center of the inner profile of the core 18. For this purpose, the holder 25 has two laterally arranged clamping elements 26 which are aligned parallel to one another and, in the installed state, interact with two opposite inner sides of the inner profile of the core, in particular the hexagon socket.

The clamping elements 26 extend axially against the installation direction and each form an angle of at least 90 °. In order to achieve a higher clamping force, the clamping elements 26 have teeth that extend against the installation direction and are angled outwards. A stop is formed at each of the free axial ends of the clamping elements 26, which limits the installation depth of the holder 25.

5 and 6 show a further embodiment of a holding body according to the invention.

The spacer frame 23 and the outer part assembly 11 are made with the components from FIGS Figures 3 and 4 identical.

In this example, the inner part assembly 12 is designed such that the abutments 16 for the heating elements 10 are arranged on the second polygon corners 14a ′. As a result, the second polygon profile 14 'is designed to be smaller than in the previous examples. The abutments 16 essentially correspond to the abutments 16 from FIGS Figures 3 and 4 . In contrast, are in the Figures 5 and 6 Example shown no contact surfaces 17 formed, since the heating elements are only in contact with the second polygon side 14b 'for a short section anyway during the relative rotation.

The core 18 essentially corresponds to the core from FIGS Figures 1 to 4 with the difference that the webs 19 connect the core 18 to the inner surfaces of the second polygon sides 14b 'and not to the inner surfaces of the second polygon corners 14a'. This has the advantage that a greater elastic deformation of the first and second polygon corners 14a, 14a 'is possible.

The control unit 20 is arranged within the core 18 by a circular holder 25. The holder 25 has clamping elements 26. The clamping elements 26 each form an angle of 90 ° and extend axially in the direction of installation. The free axial ends are inclined inward so that the holder 25 can be inserted more easily into the core 18. The clamping elements 26 each have teeth that the teeth from the Figures 3 and 4 essentially correspond. Alternatively, other shapes or structures are conceivable that increase the clamping force.

Fig. 7 shows an exemplary schematic circuit diagram in which the heating elements 10 and the components of the control unit 20 are connected to one another via a star connection. The heating elements 10 are each connected to a phase of the voltage source. The temperature monitor 21 is arranged between the strands L1 and L3 and the heating elements 10. The temperature fuse 22 is arranged between the temperature monitor 21 and the heating elements 10 of the strands L1 and L3. Another arrangement of the Components of the control unit 20 are conceivable. In the event of an excessive temperature, it is sufficient to interrupt two lines to switch off the heater.

In Fig. 8 An embodiment of a heater is shown. The heater comprises the holding body with the spacer frame 23 and the first and the second polygon profile 14, 14 '. The first and second polygon profiles 14, 14 'have ribs. Otherwise, the polygon profiles 14, 14 'essentially correspond to those in FIGS Figures 1 and 2 described polygon profiles 14, 14 '. Between the polygon profiles 14, 14 'are analogous to the Figures 1 and 2 the heating elements 10 are arranged. A grating structure 30 is arranged at the end of the holding body that is axial in the direction of the air flow. The lattice structure 30 can be connected or connected to the holding body by the fastening points 24.

An attachment 29 is arranged at the opposite axial end of the holding body. The attachment 29 comprises a fan 28, a circular disk 27 with webs and a lattice structure 30 '. The attachment 29 can be connected to the holding body, for example by plugging it on and / or by means of the fastening points 24 or locking elements. The fan 28 is arranged in the interior of the attachment 29, concentrically to the holding body. A circular disc 27 is arranged on the pressure side of the fan 28. The diameter of the circular disk 27 corresponds approximately to the diameter of the inner profile of the core 18. Other shapes are conceivable for the circular disk 27. The circular disk has webs which extend radially and can be connected to the fastening points 24. The circular disk 27 protects the fan 28 from heat radiation. Furthermore, the circular disk 27 guides the air flow into the edge regions of the holding body. I.e. the air flow does not flow through the inner profile of the core 18, but preferably only through the edge regions, in which the heating elements 10 are preferably arranged. The heating elements 10 are arranged in the region of the highest air flow. A temperature controller 21 and a temperature fuse 22 are arranged in the core 18.

Reference symbol list

10th

Heating elements

11

Outer part assembly

12

Inner part assembly

13

admission

14

first polygon profile (outer part assembly)

14 '

second polygon profile (inner part assembly)

14a

first polygon corner (outer part assembly)

14a '

second polygon corner (inner part assembly)

14b

first polygon side (outer part assembly)

14b '

second polygon side (inner part assembly)

15

Wall section

16

Abutment

17th

Contact area

18th

core

19th

web

20th

Control unit

21st

Temperature monitor

22

Thermal fuse

23

Spacer frame

24th

Attachment points

25th

bracket

26

Clamping elements

27th

Circular disc

28

fan

29

Spacer frame

30th

Lattice structure

Claims (16)

Holding body for heating elements (10), in particular oval and round heating elements (10), with an outer part assembly (11) and an inner part assembly (12) which is arranged within the outer part assembly (11) and with the outer part assembly (11) forms an elastic connection that is under mechanical tension, the outer part assembly (11) and / or the inner part assembly (12) having / having a plurality of receptacles (13) arranged distributed in the circumferential direction, in each of which a heating element ( 10) is arranged, and the outer part assembly (11) and the inner part assembly (12) each have a polygon profile (14, 14 ') with polygon corners (14a, 14a') and polygon sides (14b, 14b ') which comprise the Connect polygon corners (14a, 14a '),
characterized in that
the inner part assembly (12) and the outer part assembly (11) can be rotated relative to one another and are dimensioned such that a relative rotation between the inner part assembly (12) and the outer part assembly (11) results in the polygon profiles (14, 14 ' ) deform elastically in such a way that a press fit in the area of the heating elements (10) is formed by the induced mechanical tension in the assembled state. Holding body according to claim 1
characterized in that
in the assembled state, the heating elements (10) are arranged between the polygon sides (14b, 14b ') and / or the polygon corners (14a, 14a'). Holding body according to claim 1 or 2
characterized in that
the receptacles (13) each have wall sections (15) which are adapted to the heating elements (10) and at least partially surround them in the circumferential direction of the heating elements (10). Holding body according to claim 3
characterized in that
the wall sections (15) of a receptacle (13) are each partially formed by the outer part assembly (11) and the inner part assembly (12), a first wall section (15) having an angle of curvature of K 180 180 ° and a second wall section ( 15) is flat or has a curvature angle of K <180 °. Holding body according to one of the preceding claims
characterized in that
the outer part assembly (11) forms the receptacles (13) and the inner part assembly (11) abutment (16) for the heating elements (10) or vice versa, the heating elements (10) being pressed against the abutment (16) in the installed state are. Holding body according to claim 5
characterized in that
a contact surface (17) for the heating elements (10) is arranged in the installation direction in front of the abutments (16) in order to position the heating elements (10) in a suitable position for assembly,. Holding body according to claim 6
characterized in that
the contact surface (17) is oblique or concave. Holding body according to one of the preceding claims
characterized in that
a core (18) is arranged concentrically in the inner part assembly (12) and is connected to the inner part assembly (12) by webs (19) and / or the core (18) forms an inner profile for receiving a tool, in particular the inner profile of the core (18) for receiving a tool is designed as a hexagon socket. Holding body according to claim 8
characterized in that
A control unit (20) is arranged on the core (18) and comprises a temperature monitor (21) or a temperature controller and a temperature fuse (22) which are electrically connected to the heating elements (10) by means of a star connection. Holding body according to one of the preceding claims
characterized in that
the polygon profiles (14, 14 ') comprise at least three polygon corners (14a, 14a') and three polygon sides (14b, 14b '). Holding body according to claim 10
characterized in that
the adjacent polygon corners (14a, 14a ') of the polygon profiles (14, 14') each have the same distance angle and / or in the assembled state the polygon corners (14a, 14a ') of the polygon profiles (14, 14') are offset from one another such that the polygon corners (14a, 14a ') are aligned at least approximately centrally to the opposing polygon sides (14b, 14b'). Holding body according to claim 11
characterized in that
in the assembled state, the polygon corners (14a, 14a ') of the polygon profiles (14, 14') are aligned approximately the same. Holding body according to one of the preceding claims
characterized in that
the polygon profiles (14, 14 ') sections concave, convex or straight are formed and / or the polygon profiles (14, 14 ') have a rib structure or a lamella structure. Holding body according to one of the preceding claims
characterized in that
the outer part assembly (11) is assembled from several parts and is closed with plates, in particular aluminum plates. Heating device with a holding body according to one of the preceding claims, wherein an axial end of the holding body is connected to a fan in such a way that air can flow through the holding body in the longitudinal direction. A method for assembling a holding body according to claim 1, in which the heating elements (10) are arranged in the associated receptacles (13), then the inner part assembly (12) is inserted into the outer part assembly (11) and with a tool which is used the core (18) cooperates, is rotated until the heating elements (10) are fixed by the mechanical deformation induced by the elastic deformation of the polygon profiles (14) between the inner part assembly (12) and the outer part assembly (11).

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