FR3106398A1 - Heating body for electric heating device and liquid circulation - Google Patents

Abstract

Title of the invention: Heating body for an electric heating device and circulation of a liquid Heating body (1) for an electric heating device (2) of a heat transfer liquid (FC), the heating body ( 1) comprising at least a first support base (11) and a second support base (12) both transverse to a main axis (100) of extension of the heating body (1), the heating body (1) comprising a plurality of heating elements (3), at least one of the heating elements (3) comprising at least a first rectilinear termination (31) carried by the first base (11), a second rectilinear termination (32) carried by the second base (12), and at least one intermediate portion (33) disposed between the first rectilinear termination (31) and the second rectilinear termination (32), the intermediate portion (33) being at least partially curved by wrapping around of the main axis (100). Abstract figure: Figure 9

Description

Heating body for electric heating device and circulation of a liquid

The field of the present invention is that of electrical devices for heating and circulating a liquid, in particular for a ventilation, heating and/or air conditioning installation for the passenger compartment of a motor vehicle. More particularly, the invention relates to electric heating devices used for such installations in motor vehicles, electric or hybrid, equipped with a high-voltage power supply system.

The heating of the air intended for the heat treatment of the passenger compartment of a motor vehicle with combustion engine is ensured by heat exchange between a flow of air and a heat transfer liquid, by means of a heat exchanger. In the case of hybrid or electric vehicles, electric heating devices are known which form a source of calories and in which an electric current is circulated to raise the temperature of a heating element on board this heating device. The liquid to be heated thus passes through the heating device and is brought into contact with the heating element, an exchange of calories then takes place between the heating element and the liquid intended for heating the passenger compartment, which then heats up to his turn.

The heating element usually consists of electrical heating means, for example one or more heating resistors. In order to obtain sufficient heating power for the desired operation, it may be necessary to multiply the heating elements in the same electric heating device.

The multiplication of the number of heating elements can be accompanied by constraints. Indeed, the number of heating elements integrated in the electric heating device is limited due to the large size generated when the number of heating elements increases in order to reach the required levels of performance. Such a drawback is particularly observed in electric heating devices in which electrical terminals of the various heating elements are arranged on the same side of the electric heating device so as to ensure their connection to an electrical power supply system. Such an arrangement is accompanied by a limitation of the number of heating elements that can be integrated into the electric heating device and therefore a limitation of the power that can be generated by the latter. Moreover, such electric heating devices conventionally have a low capacity for regulating the power generated.

The constraints of limiting the size generated by the heating elements, while ensuring ever higher degrees of power and performance, remain essential problems for vehicles, in particular electric or hybrid motor vehicles, and it is in this context of the invention.

The object of the present invention is thus to propose a heating body whose power can be increased, by the addition of heating elements, and regulated in a more suitable manner, while limiting the size generated by the addition of such heating elements.

The present invention falls within this context and aims to provide a heating element for an electric heating device for a heat transfer liquid, the heating element comprising at least a first support base and a second support base, both of which are transverse to a main axis of extension of the heating body, the heating body comprising a plurality of heating elements, at least one of the heating elements comprising at least a first rectilinear termination carried by the first base, a second rectilinear termination carried by the second base, and at least one intermediate portion disposed between the first termination and the second termination, the intermediate portion being at least partially curved by winding around the main axis.

By convention, throughout this document, the qualifier “longitudinal” applies to the direction in which the main axis of the heating body extends. Thus, according to the invention, the plurality of heating elements is, at least in part, longitudinally interposed between the first base and the second base.

Such a heating body and such an electric heating device are in particular intended for a hybrid or electric motor vehicle, which can, for example, be designed to operate with a so-called high-voltage power supply, generally greater than 50V.

By “base” is meant both a support element or base of at least one of the heating elements which may, for example, be substantially planar, such as a plate, or which may have a more complex shape, for example a cup shape.

By “heating element” is meant, for example, one or more tubular electrical resistors which may be electrically connected in series or in parallel.

According to a particular embodiment, the first base and the second base are provided with orifices allowing the insertion and the fixing, in a sealed manner, of the various heating elements. In this way, each first rectilinear termination and second rectilinear termination crosses, respectively, the first base and the second base.

In particular, in order to prevent deformation of the first base and of the second base, said heating elements may comprise at least one non-heating zone, located at the level of their insertion seats in the first base and second base. Furthermore, or alternatively, the first base and/or the second base can be made of a heat-resistant material.

According to the invention, the first rectilinear termination and the second rectilinear termination of at least one of the heating elements are separated by an angular sector with an angle α greater than or equal to 90° in which the portion extends at least partially intermediate.

Said angular sector is defined by two half-lines included in a section plane orthogonal to the main axis, these half-lines coming from the same point on the main axis and passing through a center of a section of the first rectilinear termination for a first half-line, and by a center of a section of the second rectilinear termination for a second half-line.

According to a particular embodiment, the first rectilinear termination and the second rectilinear termination of at least one of the heating elements are separated by an angular sector whose angle α is greater than or equal to 360° and in which extends least partially the intermediate portion.

According to the invention, the plurality of heating elements can be arranged so that at least a part of the first rectilinear terminations fits into a first circle in the first base and/or at least a part of the second rectilinear terminations of the elements heating fits in a second circle in the second base.

In particular, the first circle and the second circle can be centered on the same axis. According to a particular embodiment, this axis can be the main axis.

Alternatively, the plurality of heating elements may be arranged so that at least a part of the first rectilinear terminations fits into a first polygon in the first base and/or at least a part of the second rectilinear terminations of the heating elements fits into a second polygon in the second base.

According to a first embodiment of the invention, the heating elements can be arranged according to a first subset and according to a second subset, the first subset delimiting a first volume in which the the heating element(s) of the second subassembly.

In other words, the first subset surrounds the heating element(s) of the second subset.

By way of example, at least part of the first rectilinear terminations of the heating elements of the first subset can be inscribed in the first circle or in the first polygon as previously explained. Similarly, at least part of the second rectilinear terminations of the heating elements of the first subset can be inscribed in the second circle or in the second polygon.

According to the first embodiment, the heating element(s) of the second subset delimit(s) a second volume, the first volume of the first subset and the second volume of the second subset being concentric. That is to say that a first circumference, specific to the first volume, and a second circumference, specific to the second volume, are centered on the same axis. According to a particular embodiment, this axis is the main axis.

According to this first embodiment, the intermediate portion of at least one of the heating elements is of helical shape.

A "helical shape" is understood to mean a regular movement combining translation and rotation around an axis so as to form at least a portion of a helix of specific diameter. In particular, this helical shape can be centered on the main axis.

Optionally, the heating elements of the same sub-assembly, for example the first sub-assembly and/or the second sub-assembly, can be characterized by a helical shape of the substantially identical intermediate portion.

According to a second embodiment, the intermediate portion of at least one of the heating elements comprises at least a first part and a second part respectively characterized by a first winding direction and a second winding direction around a extension axis of the heating element passing the centers of the section of a free end of the first rectilinear termination and of the section of a free end of the second rectilinear termination of the heating element considered, the first direction winding and the second direction of winding being opposite.

According to the invention, the intermediate portion of at least one heating element comprises an intermediate segment disposed between the first part and the second part, the intermediate segment being closer to the main axis of the heating body than the first part or the second part.

In other words, the intermediate segment converges, at least in part, towards the main axis of the heating body, that is to say that the distance measured between the main axis and a central point of a section of the intermediate segment is less than the distance measured between said main axis and a central point of a section of the first part or of the second part of the intermediate portion of the heating element.

In particular, the intermediate segment can be at least partially curved and/or at least partially straight.

According to a particular embodiment, the heating elements can be arranged according to at least a first subset and/or a second subset and a third subset, the intermediate portion of the heating elements of the third subset comprising the segment intermediary, at least one heating element of the first sub-assembly and/or of the second sub-assembly being interposed between two heating elements of the third sub-assembly.

The invention also relates to a device for electric heating of a heat transfer liquid comprising a casing which delimits an internal volume in which extends a heating body as described above, the internal volume being divided into at least:

- a first cavity delimited by at least a first end wall of the casing and the first base of the heating body and in which the first rectilinear terminations of the heating elements extend at least partially;

- a heat transfer liquid circulation chamber bordered by the first base and the second base and in which the heating elements of the heating body mainly extend;

- a second cavity delimited by a second end wall of the casing and by the second base of the heating body and in which the second rectilinear terminations of the heating elements extend at least partially.

According to the invention, the electric heating device comprises at least one electric heating device control device configured to selectively supply a first sub-group and/or a second sub-group of the plurality of heating elements of the heating body by electric energy.

Alternatively, the heating device according to the invention can be configured to independently power each of the heating elements that it comprises.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the detailed description given below, and several examples of embodiment given by way of indication and not limitation with reference to the appended schematic drawings, in which:

is a schematic representation in perspective of a heating body according to the invention produced according to a first embodiment;

is a schematic representation in perspective of part of the heating body shown in Figure 1;

is a schematic representation of the arrangement of heating elements of a first sub-assembly and of a second sub-assembly in the heating body as illustrated in FIG. 1;

is a schematic representation of the arrangement of one of the heating elements in the heating body when the latter is made according to an alternative of the first embodiment;

is a schematic representation of the arrangement of heating elements of the first sub-assembly and of the second sub-assembly in the heating body according to the alternative of the first embodiment;

is a schematic representation in perspective of part of the heating body produced according to a second embodiment;

is a schematic representation in perspective of a part of the heating body illustrated in FIG. 6, represented according to a first view;

is a schematic representation in perspective of part of the heating body illustrated in FIG. 6, represented according to a second view;

is a schematic representation in perspective of a device for electric heating of a heat transfer liquid comprising the heating body;

First of all, it should be noted that if the figures expose the invention in detail for its implementation, they can of course be used to better define the invention if necessary. It should also be noted that, in all of the figures, similar elements and/or fulfilling the same function are indicated by the same reference.

In the figures, the denominations longitudinal, transverse, lateral, left, right, above, below, refer to the orientation, in a trihedron L, V, T. In this frame, a longitudinal axis L represents a longitudinal direction, a transverse axis T represents a transverse direction, and a vertical axis V represents a vertical direction of the object under consideration.

Figures 1 to 3 illustrate an example of a heating body 1 intended for an electric heating device for a heat transfer liquid FC, for example glycol water, produced according to a first embodiment. Such an electric heating device is, for example, intended for a ventilation, heating and/or air conditioning installation of a hybrid or electric vehicle. The heating body 1 comprises a first support base 11 and a second support base 12 both transverse to a main axis 100 of extension of the heating body 1, here substantially parallel to the longitudinal direction. In this case, the first base 11 and the second base 12 are particularly arranged so as to extend parallel to each other and orthogonal to the main axis 100. Such bases 11, 12 can, for example, be made of a heat-resistant material.

In this case, the bases 11, 12 have a substantially planar shape, that is to say a plate shape. Alternatively, at least one of the bases 11, 12 may have a more complex shape, for example a cup shape.

The heating body 1 also comprises a plurality of heating elements 3 intended to heat the heat transfer liquid and consisting, for example, of heating resistors.

According to the invention, at least one of the heating elements 3 comprises at least a first rectilinear termination 31, a second rectilinear termination 32 and at least one intermediate portion 33 disposed between the first rectilinear termination 31 and the second rectilinear termination 32. Particularly , the heating elements 3 illustrated have a substantially tubular shape and extend from the first rectilinear termination 31, along the intermediate portion 33 and to the second rectilinear termination 32.

In the heating body 1 represented, each of the heating elements 3 illustrated comprises the first rectilinear termination 31, the second rectilinear termination 32 and the intermediate portion 33. It is understood that, throughout the description below, the characteristics described in relation to one of the heating elements 3 can be extended to all of the heating elements 3 of the electric heating device. In particular, in the example illustrated, the section of each heating element is circular and substantially identical, illustrating the fact that they are composed of resistive strands of dimensions, here of diameter, similar, or substantially similar. Alternatively, these dimensions may vary from one heating element 3 to another.

The first rectilinear termination 31 and the second rectilinear termination 32 extend in a direction substantially parallel to the main axis 100 of the electrical heating device and comprise, at their free ends, electrical terminals 34, comprising, for example, a terminal 35 so as to allow electrical connection of the heating element 3 to a supply system, not shown, of the vehicle.

The first rectilinear termination 31 is carried by the first base 11 while the second rectilinear termination 32 is carried by the second base 12. Each heating element 3 is thus inserted and fixed at the level of orifices 111, 121 made in the first base 11 and in the second base 12. The orifices 111, 121 shown in dotted lines illustrate, by way of example, different insertion sites of the heating elements 3 in the first base 11 and the second base 12 respectively. In this way, the first rectilinear termination 31 crosses at least in part the first base 11 which is thus interposed between the intermediate portion 33 and the terminal 35 carried by the first rectilinear termination 31. Similarly, the second rectilinear termination 32 crosses at least in part the second base 12 and the second base 12 is interposed between the intermediate portion 33 and the terminal 35 carried by the second rectilinear termination 32. By way of example, the heating elements 3 can be kept integral with the first base 11 and/ or the second base 12 by welding, in particular by electrofusion.

Advantageously, maintaining the various heating elements 3 at each of their rectilinear ends 31, 32, longitudinally opposite, contributes to reducing the vibrations of these heating elements 3 during operation of the electric heating device, thus reducing the noise generated, likely to inconvenience a user of the vehicle, and the risk of damage to these heating elements 3. Advantageously and as shown, the first base 11 and the second base 12 can be arranged on either side and at equal distance from a median plane 5500, substantially orthogonal to the main axis 100 and dividing the heating body 1 into two substantially equal parts.

The intermediate portion 33 is at least partially curved so as to wrap around the main axis 100. According to the first embodiment, illustrated in FIGS. 1 to 3, the intermediate portion 33 is particularly of helical shape, it is that is to say that it is comparable to a helix winding regularly around a winding axis 150, here merged with the main axis 100.

The winding direction of the intermediate portion 33 corresponds to the direction, clockwise or anti-clockwise, of the movement performed by the intermediate portion 33 considered by moving along the winding axis 150 and seen from the first rectilinear termination 31 of said heating element 3. Thus for the intermediate portion 33 illustrated, for example visible in Figures 2 and 3, the intermediate portion 33 winds clockwise.

Such a winding of the intermediate portion 33 contributes to increasing the length of the heating element 3, in particular of its intermediate portion 33, and therefore the heating power of the heating body 1, while limiting the size it generates.

In particular, the points of the same intermediate portion 33 furthest from the winding axis 150 are part of a surface, called the outer surface 331 of the intermediate portion 33, while the points of the intermediate portion 33 furthest close to the winding axis 150 are part of a surface called the inner surface 332.

The intermediate portion 33 is thus centered on the winding axis 150, and therefore on the main axis 100, and is characterized by a diameter, called the first winding diameter 330, which is constant throughout the entire intermediate portion 33 of the heating element 3. The first winding diameter 330 corresponds to the diameter of a disc situated in a plane orthogonal to the winding axis 150 of the heating element 3, this disc resulting from the projection of the points of the outer surface 331 of the intermediate portion 33 on said orthogonal plane.

The helical shape of the intermediate portion 33 is also characterized by a first pitch, not represented here, that is to say a regular interval separating two successive turns of the same intermediate portion 33. By “turn”, we mean a winding of the helix of the intermediate portion 33 corresponding to a complete rotation, that is to say a rotation of 360°, while a half-turn corresponds to a rotation of 180°. Also, for the sake of clarity, a length of half a turn of the intermediate portion 33 will be referred to as the first half step 335.

The first pitch and the first half-pitch 335 are measured along the winding axis 150, between two points respectively included in the outer surface 331 of two successive turns or half-turns of the intermediate portion 33 considered. This first step and this first half step 335 are constant throughout the entire intermediate portion 33.

According to one aspect of the invention and in particular in the first embodiment, the heating body 1 is configured so that the first rectilinear termination 31 and the second rectilinear termination 32 of the same heating element 3 are separated by an angular sector of angle α greater than or equal to 90°, at least part of the intermediate portion 33 extending in this angular sector. In other words, the intermediate portion 33 of the heating element 3 has, for the first embodiment, a rotation of a value substantially equal to the angle α. This angular sector is defined by two half-lines included in a section plane orthogonal to the main axis 100 and issuing from the same point of the main axis 100. A first half-line 1000 passes through a center 36 of a section of the first rectilinear termination 31 while a second half-line 2000 passes through a center 36 of a section of the second rectilinear termination 32.

In the example illustrated in Figure 1, the angular sector is characterized by an angle α of the order of 216°, it is understood that such a representation is made for information only and is in no way limiting.

Within the heating body 1, at least a part of the plurality of heating elements 3 can be characterized by a winding direction and/or a first winding diameter 330 and/or a first pitch, or first half pitch 335, and/or a substantially identical angle α. The heating element 1 illustrated in FIGS. 1 to 3 thus represents a particular embodiment in which the heating elements 3 represented are substantially identical to each other, that is to say that they are characterized by a direction of winding, a first winding diameter 330, a first pitch and an identical angle α. Such uniformity of the heating elements 3 is accompanied, advantageously, by a simplification of the production of the heating body 1 but also by a reduction in the costs of this production.

In the heating body 1, the plurality of heating elements 3 as previously explained can be arranged so that at least a part of the first rectilinear terminations 31 fits into a first circle 310, included in the first base 11, and/or so that at least a part of the second rectilinear ends 32 of the heating elements 3 fits into a second circle 320, included in the second base 12. In particular, the same heating elements 3 can fit into the first circle 310 and in the second circle 320. In particular, these first circle 310 and second circle 320 can be concentric, that is to say centered on the same axis, for example the winding axis 150 and/or main axis 100.

This first circle 310 and this second circle 320 are respectively defined by the centers 36 of the sections of the first rectilinear terminations 31 and by the centers 36 of the sections of the second rectilinear terminations 32.

Furthermore, and as illustrated, the heating elements 3 inscribed in the first circle 310 and/or in the second circle 320 can be regularly arranged. That is to say that adjacent first rectilinear terminations 31, inscribed in the first circle 310, can be separated by identical spacings 315, measured along the first circle 310, between the centers 36 of the sections of these first rectilinear terminations 31. The same goes for the second rectilinear terminations 32 arranged in the second circle 320. Optionally, the second rectilinear terminations 32 which may have a spacing 35 identical to that observed in the first circle 310. Such a spacing 315 will be all the more reduced as the number of heating elements 3 included in the heating body 1, and more particularly in the first circle 310 and/or in the second circle 320, increases. It should be noted that the heating elements 3 are nevertheless not in contact with each other, the spacing 315 present between the rectilinear terminations 31, 32 of these heating elements 3 being subjected, on the one hand, to the constraints of dimensions relating to the electrical connection of each heating element 3, and, on the other hand, to the prevention of contact between adjacent heating elements 3.

According to the first embodiment, the heating elements 3 of the heating body 1 can also be arranged according to a first sub-assembly 4 and according to a second sub-assembly 5. The first sub-assembly 4 thus delimits a first volume 400 in which extends the heating element(s) 3 of the second sub-assembly 5.

For purposes of clarity in the description of the first embodiment below, the terms "primary heating elements 43", "heating elements 3 of the first subassembly 4" or "first subassembly 4" will be used without distinction. on the one hand, and the terms “secondary heating elements 53”, “heating elements 3 of the second sub-assembly 4” and “second sub-assembly 5” on the other hand. It is understood that the terms “primary” and “secondary” have the function here of distinguishing the heating elements 3 of these different sub-assemblies 4, 5 and in no way reflect a hierarchy of the heating elements 3 within the heating body 1 .

The term "first volume 400" means a space included, moving along the direction defined by the main axis 100, in a first circumference 40 of the first subset 4, delimited by points included in the interior surfaces 332 of each of the heating elements 3 of the first subset.

In other words, the heating elements 3 of the first subset 4 surround the heating elements 3 of the second subset 5.

In this case, the first sub-assembly 4 comprises ten primary heating elements 43 and the first circumference 40 is of substantially circular shape due to the arrangement of the various heating elements 3 of the first sub-assembly 4 along the first circle 310 and of the second circle 320. The secondary heating elements 53 can, for example, be four in number, as illustrated in FIG. 9, examples of orifices 111, 121 for inserting these secondary heating elements 53 into the first base 11 and in the second base 12 being shown in dotted lines in Figures 1 to 3.

As previously explained, the secondary heating elements 53 are characterized by a winding direction of their intermediate portion 33. Also, these secondary heating elements 53 are characterized by a diameter, here referred to as the second winding diameter for the purposes of clarity. , and a second pitch or second half pitch, not shown, which are respectively similar to the first winding diameter 330 and to the first pitch, or first half pitch 335, of the primary heating elements 43. Also the descriptions of these characteristics can be transposed to the heating elements 3 of the second sub-assembly 5. In particular, as explained above, the winding direction and/or the second winding diameter and/or the second pitch, or second half pitch, of the secondary heating elements 53 can vary from one heating element 3 to another. Furthermore, the winding direction and/or the second pitch, or second half pitch, of at least one of the secondary heating elements 53 may or may not be substantially identical to the winding direction and the first pitch, or first half pitch 335, of at least one of the primary heating elements 3.

It should be noted that, due to the arrangement of the heating elements of the second sub-assembly 5 within the first volume 400, the second winding diameter specific to each of these secondary heating elements 53 is strictly less than the first diameters of winding 330 of the primary heating elements making up the first sub-assembly 4 as well as a diameter of the first circumference 40 of the first volume 400.

In particular, the heating elements 3 of the second sub-assembly 5 delimit a second volume 500, shown schematically in FIG. main axis 100, in a second circumference 50 of the second sub-assembly 5, here substantially circular, delimited by points included in the outer surfaces 332 of each of the heating elements 3 of the second sub-assembly 5. This second volume 500 is less than the first volume 400, and is arranged in the first volume 400 so that the heating elements 3 of the first sub-assembly 4 and the heating elements 3 of the second sub-assembly 5 do not come into contact with each other, whether either at their rectilinear ends 31, 32 or at their respective intermediate portions 33.

The second volume 500 can be arranged variably inside the first volume 400. According to the example illustrated, the first volume 400 of the first subset 4 and the second volume 500 of the second subset 5 can be concentric. That is to say that the first circumference 40 of the first volume 400 and the second circumference 50 of the second volume 500 are centered on the same axis, here the main axis 100. In this way, a distance separating the main axis 100 and all of the heating elements 3 of the second sub-assembly 5 is less than a distance separating the main axis 100 from different heating elements 3 of the first sub-assembly 4.

Figures 4 and 5 illustrate an example of an alternative of the first embodiment substantially identical to what has been previously explained except that at least one of the heating elements 3 is arranged so that its first rectilinear termination 31 and its second rectilinear termination 32 are separated by an angular sector with an angle α greater than or equal to 360°, the intermediate portion 33 of the heating element 3 extending at least partially in this angular sector. In other words, the intermediate portion 33 of this heating element 3 performs at least one rotation of 360°, thus advantageously increasing the length of the intermediate portion 33 of the heating element 3.

In this case, the first rectilinear termination 31 and the second rectilinear termination 32 of the heating element 3 shown are separated by an angular sector with an angle α equal to 360°. That is to say that the first pitch proper to the intermediate portion 33 of this heating element 3 is equal to a length of this intermediate portion 33, measured between two longitudinal extremes of the intermediate portion 33, along the axis main 100. Also, the centers 36 of the sections of the first rectilinear termination 31 and of the second rectilinear termination 32 of the heating element 33 are included on the same extension axis 3000, substantially parallel to the main axis 100.

It is understood that such an arrangement can be extended to all of the heating elements 3 of the heating body or, alternatively, to at least some of the heating elements of the first sub-assembly 4 and/or of the second sub- together 5.

Figures 6 to 8 illustrate the arrangement, according to a second embodiment, of a plurality of heating elements 3 of the heating body 1. For the purposes of clarity, the heating body 1 illustrated in Figure 6 is devoid of the first base 11. Furthermore, the first base 11 and the second base 12 are shown schematically in dotted lines in Figures 7 and 8, which illustrate part of the heating elements 3 of the heating body 1.

Similar to what was previously explained with reference to the first embodiment, the heating body 1 comprises the first base 11 and the second base 12, both transverse, here orthogonal, to the main axis 100 of extension of the body heating element 1. Likewise, the heating body 1 comprises a plurality of heating elements 3, at least one of which successively comprises, moving along the main axis 100, the first rectilinear termination 31, the intermediate portion 33 and the second rectilinear termination 32.

As previously explained, the first rectilinear termination 31 and the second rectilinear termination 32 are arranged so as to be separated by an angular sector with an angle α greater than or equal to 90° and in which the intermediate portion 33 extends at least partially. In this case, the angle α is substantially identical for each of the heating elements 3 of the heating body 1 illustrated, this angle α being approximately equal to 180°.

According to an alternative not shown of the second embodiment, at least one of the heating elements 3 can be arranged so that its first rectilinear termination 31 and its second rectilinear termination 32 are separated by an angular sector with an angle α greater than or equal to 360°.

In this second embodiment, the intermediate portion 33 of at least one of the heating elements 3 comprises at least a first part 37 and a second part 38, both substantially curved around an extension axis 3000 of the heating element which passes through the center 36 of a section of a free end of the first rectilinear termination 31 and through the center 36 of a section of a free end of the second rectilinear termination 32 of the heating element 3 considered.

The first part 37 is connected to the first rectilinear termination 31 and is characterized by a first winding direction around the extension axis 3000 of the heating element 3. Similarly, the second part 38 is connected to the second termination rectilinear 32 and is characterized by a second winding direction around the extension axis 3000 of the heating element 3. According to this second embodiment, the first winding direction and the second winding direction are opposite . As explained above, the direction of winding corresponds to the direction, clockwise or anti-clockwise, of the movement performed by the first part 37 or the second part 38 of the intermediate portion 33 considered seen from the first rectilinear termination 31 of said heating element 3 and by moving along the axis of extension 3000, that is to say from the first rectilinear termination 31 towards the second rectilinear termination 32.

According to a particular embodiment, not illustrated, the first part 37 and/or the second part 38 of the intermediate portion 33 may have a substantially helical shape.

The heating element 1 illustrated in FIGS. 6 to 8 comprises three distinct sub-assemblies, each of the heating elements 3 of the same sub-assembly being able, according to a particular embodiment, to be substantially identical to one another. For clarity, Figures 7 and 8 illustrate three heating elements 3: a first heating element 41, a second heating element 51 and a third heating element 61 respectively included in a first sub-assembly 4, a second sub-assembly 5 and a third sub-assembly 6 of the second embodiment.

In the first heating element 41, the first part 37 extends between the first rectilinear termination 31 and a first demarcation 71 while the second part 38 extends between the first demarcation 71 and the second rectilinear termination 32. The first part 37 wraps at least partially around an axis of extension 3000, called the first axis of extension 710, passing through the centers 36 of the sections of the free ends of the rectilinear terminations 31, 32 of the first heating element 41, in a first direction winding, here anti-clockwise. The second part 38 wraps at least partially around the first extension axis 710 according to an opposite winding direction, in this case clockwise. Such an arrangement can in particular be extended to all of the heating elements 3 of the first subset 4.

In the second heating element 51, the first part 37 extends between the first straight termination 31 and a second demarcation 72 while the second part 38 extends between the second demarcation 72 and the second straight termination 32. The first portion 37 of the second heating element 51 wraps at least partially around a second axis of extension 720, passing through the centers 36 of the sections of the free ends of the rectilinear terminations 31, 32 of the second heating element 51, according to a first direction of winding, in this case clockwise. Conversely, the second part 38 of the second heating element 51 is rolled up at least partially around the second extension axis 720 according to a second winding direction, opposite to the first winding direction of the second heating element 51, i.e. say counter-clockwise. Such an arrangement can in particular be extended to all of the heating elements of the second subset 5.

Alternatively, the heating elements 3 of the first sub-assembly 4 and of the second sub-assembly 5 can have the same first direction of winding, for example the clockwise direction, and the same second direction of winding, for example the direction anti-clockwise.

In the third sub-assembly 6, the intermediate portion 33 of at least one of the heating elements 3, here a third heating element 61, comprises an intermediate segment 39 placed between the first part 37 and the second part 38. In the example illustrated, the intermediate segment 39 is, in a non-limiting manner, substantially curved so that it wraps at least partially around a third extension axis 735 specific to the third heating element 61. In particular, this intermediate segment 39 is closer to the main axis 100 of the heating body 1 than the first part 37 or the second part 38, in particular so as to converge towards the main axis 100 to densify the available power. In other words, the distance measured, in a direction orthogonal to the main axis 100, between the main axis 100 and a central point, not shown, of a section of the intermediate segment 39 is less than the distance measured between said main axis 100 and a central point, not visible, of a section of the first part 37 or of the second part 38 of the intermediate portion 33 of the heating element 3.

In this third heating element 61, a first part 37 of the third heating element 61 extends between the first rectilinear termination 31 and a third demarcation 73 and wraps, at least partially, around the third axis of extension 735 along a first winding direction, here clockwise. A second part 38 of the third extends between a fourth demarcation 74 and the second rectilinear termination 32 of the third heating element 61 and is wound at least partially around the third axis of extension 735 according to a second winding direction, opposite to the first winding direction of the third heating element 61, that is to say in the anti-clockwise direction. In other words, the intermediate segment 39 extends between the third demarcation 73 and the fourth demarcation 74. Such an arrangement can be extended to all the heating elements of the third subset 6.

Similar to the first embodiment, at least a part of the first rectilinear terminations 31 of these heating elements 3 fits into the first circle 310, included in the first base 11, and/or at least a part of the second rectilinear terminations 32 of the heating elements 3 are inscribed in the second circle 320, included in the second base 12. In the example illustrated, all of the heating elements 3 are inscribed in the first circle 310 and in the second circle 320, these first circle 310 and second circle 320 being in particular concentric and centered on the main axis 100 of the heating body 1.

Furthermore, the relative arrangement of the heating elements 3 of the first sub-assembly 4, of the second sub-assembly 5 and of the third sub-assembly 6 illustrated by the first heating element 41, the second heating element 51 and the third heating element 61 , visible in Figures 7 and 8, can be reproduced and repeated within the heating body 1, as shown in Figure 6. Thus, the heating elements 3 included in the third subassembly 6 can be interposed between an element heater 3 of the first subset and a heating element 3 of the second subset. In other words, at least one heating element 3 of the first sub-assembly 4 and/or of the second sub-assembly 5 is interposed between two heating elements 3 of the third sub-assembly 6.

Specifically, these heating elements can be regularly inscribed in the first circle 310 and/or in the second circle 320. Optionally, these heating elements s3 can be separated, as previously explained, by substantially identical spacings 315. It is nevertheless understood that the different heating elements 3 are not in contact with each other.

FIG. 9 illustrates an electric heating device 2 for a heat transfer liquid FC comprising a heating body 1 as previously explained. In the example illustrated, the electric heating device 2 comprises an example of a heating body 1 produced according to the first embodiment, the electric heating device 2 may nevertheless comprise a heating body 1 according to any one of embodiments, or alternatives, previously exposed.

The electric heating device 2 comprises a casing 81 which delimits an internal volume 800 in which the heating body 1 extends. For clarity, this casing 81 is partially represented in transparency so as to make the heating body visible 1. In particular, the housing 81 may comprise at least one main block 82 which extends along a straight line of extension 5000, here substantially parallel to the longitudinal direction, and which comprises at least one side wall 821. In the example shown, the side wall 821 has, in a non-limiting manner, a substantially circular cross-section. In order to allow the insertion of the heating body 1, such a main block 82 is open on at least one side transverse to the longitudinal direction. Particularly, the main block 82 of the casing 81 can be opened on two sides extending transversely to the longitudinal direction.

The housing 81 also includes at least a first end wall 811 and a second end wall 812, extending transversely to the longitudinal direction. In particular, the first end wall 811 and/or the second end wall 812 can be included in at least one cover attached to a longitudinal end of the main block 82 of the box 81. In this case, the box 81 comprises two covers, a first cover 831 comprising the first end wall 811 of the casing 81 and closing a first open side 822 of the main block 82 and a second cover 832 comprising the second end wall 812 and closing a second open side 823 of this same main block 82.

When the electric heating device 2 is assembled and the heating body 1 is installed in the casing 81, the latter divides the internal volume 800 into a first cavity 801 and a second cavity 802, in which extend at least in part, respectively the first rectilinear terminations 31 and the second rectilinear terminations 32 comprising the electrical terminals 34 of the heating elements 3, and a chamber 803 for the circulation of the heat transfer liquid FC, in which the heating elements 3 of the heating body mainly extend 1.

The first cavity 801 is at least delimited by the first end wall 811 of the casing 81 and by the first base 11 of the heating body 1 while the second cavity 802 is at least delimited by the second end wall 812 of the casing 81 and by the second base 12 of the heating body 1.

The heat transfer liquid circulation chamber 803 FC is longitudinally interposed between the first cavity 801 and the second cavity 802 and thus delimited by the first base 11 and the second base 12. Advantageously, the electric heating device 2 can comprise at least one seal, not shown, such as an annular gasket, arranged at the level of the first base 11 and/or of the first base 11, so as to ensure the sealing of the chamber 803 and to prevent the infiltration of liquid coolant at the level of the first cavity 801 and/or the second cavity 802, housing electrical components of the electrical heating device 2.

The circulation of the heat transfer liquid FC within the chamber 803 is ensured by means of a supply pipe 84 and an evacuation pipe 85, connected to a heat transfer liquid circuit, not shown, and opening respectively into the chamber 803 of the electric heating device 2 at the level of a supply opening 841 and an evacuation opening, not visible. The heat transfer liquid to be heated is thus brought to the chamber 803 via the supply pipe 84, then circulates in the chamber 803, between the heating elements 3, and, by contact with these heating elements 3, is mounted in temperature. The heat transfer liquid thus heated is evacuated from the electric heating device 2 at the level of the evacuation pipe 85 and sent to the heat transfer liquid circuit, for example in order to ensure the heat treatment of a passenger compartment of the vehicle. It is understood that the supply line 84 and discharge line 85 are shown here for information only, their shape and position not being limiting in any way.

In the chamber 803, the heating body 1 is arranged so that the heating elements 3 do not come into contact with the side wall(s) of the box 81. In particular, the heating body 1 can be centered in the chamber 803, for example so that the extension line 5000 of the casing, substantially parallel to the longitudinal direction, and the main axis 100 of the heating body 1 coincide. Such an arrangement aims in particular to ensure a homogeneous distribution of the heating elements 3 within the chamber 803 as well as a good distribution of the volumes of heat transfer liquid FC in the chamber 803.

The electrical heating device 2 is also connected to an electrical power supply system, not shown, so as to supply electrical energy to the various heating elements 3 of the heating body 1.

Each heating element 3 is connected to the power supply system through its own electrical terminals 34. The electrical terminals 34 are connected to the power supply system via conductive members 86, for example cables, pins or conductive strips, examples of which are schematically illustrated for one of the heating elements 3. These members conductors extend at least partly in the first cavity 801 or at least partly in the second cavity 802 depending on whether they are connected to the electrical terminal 34 carried by the first rectilinear termination 31 or by the second rectilinear termination 32 of the heating element 3. All of these conductive members 86 then extend in the same housing 804, partially delimited by the side wall(s) 821 and by an annex block 87 of the casing 81, open on at least at least one side and intended to accommodate at least one control device 88 of the electric heating device 2. This housing 804 extends, by way of example, over the main block 82, along the chamber 803 and ensures the maintenance electrical and/or electronic components of the electric heating device 2 at a distance, and physically separated, from the circulation of the heat transfer liquid FC.

A cover 871 of the electric heating device 2, configured to close the annex block 87, carries at least one power connector 872 at the level of which the various conductive members 86 are assembled. By way of example, the power connector 872 can be oriented in the vertical direction, that is to say perpendicular to the extension line 5000 of the housing 81 of the electric heating device 2.

The annex block 87 notably comprises at least a first hole 873 and a second hole 874, respectively included in at least a part of a first extreme edge 875 and a second extreme edge 876 of the annex block 87, configured to let the conductive members pass 86 extending between the first cavity 801 or the second cavity 802 and the housing 804. According to a particular embodiment, the first cover 831 and/or the second cover 832 can extend at least in part facing the first edge extreme 875 and the second extreme edge 876 respectively, so that the first hole 873 opens into the first cavity 801 and the second hole 874 opens into the second cavity 802.

The control device 88 of the electric heating device 2 is particularly configured to ensure a selective supply of electric energy to at least a first sub-group 91 and/or a second sub-group 92 of the plurality of heating elements 3 of the heating body 1. In other words, the electric heating device 2 can implement, depending on the heating power required, different operating modes making it possible to electrically supply a defined number of heating elements 3, when a low heating power is required, or to power all of the heating elements 3, for example when the electric heating device 2 must provide a high heating power. Due to the large number of heating elements 3 within the heating body 1, the electric heating device 2 according to the invention advantageously allows, compared to conventional electric heating devices, a more refined control of the power generated by the electrical heating device 2, and therefore the electrical energy consumption of said device 2.

By way of example, each of the heating elements 3 can be supplied with electrical energy independently of the other heating elements 3, the first sub-group 91 thus corresponding to one of the heating elements 3 of the heating body 1 and the second sub-group 91 group 92 corresponding to a separate heating element 3.

Alternatively, the first sub-group 91 may comprise at least a part, or even all, of the heating elements 3 making up one of the sub-assemblies 4, 5, or even 6, as previously explained in the different embodiments while the second sub-group comprises at least one of the heating elements 3 of a distinct sub-assembly.

In this case, the heating body 1 illustrated is an embodiment of the heating body 1 according to the first embodiment. The first sub-group 91, selectively powered by the control device, can be the first sub-assembly 4 of heating elements 3 and the second sub-group 92 can be the second sub-assembly 5. Such an arrangement allows to selectively supply the heating elements 3 placed centrally in the chamber 803, that is to say close to the extension line 5000 of the box 81, and therefore to the main axis 100 of the heating body 1, and/or of the heating elements 3 arranged in a peripheral manner in the chamber 803, that is to say the heating elements 3 closest to the side wall(s) 812 of the case 81.

It is understood on reading the foregoing that the present invention proposes a heating body intended for an electric heating device for a heat transfer liquid, this heating body being configured to reduce the size of the electric heating device, while maintaining or increasing its thermal performance. This heating body, intended in particular to cooperate with a ventilation, heating and/or air conditioning installation for an electric or hybrid vehicle, has its dimensions optimized due to the particular arrangement of the various heating elements and allows a refined control of the heating power generated compared to prior art fluid heating devices.

The invention cannot however be limited to the means and configurations described and illustrated here, and it also extends to any equivalent means or configuration and to any technical combination operating such means. In particular, the number of heating elements, the pitch of the intermediate portions of said heating elements, their diameter or even their degree of rotation may be modified without harming the invention, insofar as the electric heating device for a vehicle, in fine, performs the same functionality as described in this document.

Claims (10)

Heating body (1) for an electric heating device (2) for a heat transfer liquid (FC), the heating body (1) comprising at least a first base (11) of support and a second base (12) of support both transverse to a main axis (100) of extension of the heating body (1), the heating body (1) comprising a plurality of heating elements (3), at least one of the heating elements (3 ) comprising at least a first rectilinear termination (31) carried by the first base (11), a second rectilinear termination (32) carried by the second base (12), and at least one intermediate portion (33) arranged between the first termination rectilinear (31) and the second rectilinear termination (32), the intermediate portion (33) being at least partially curved by winding around the main axis (100). Heating body (1) according to the preceding claim, in which the first rectilinear termination (31) and the second rectilinear termination (32) of at least one of the heating elements (3) are separated by an angular sector of angle α greater than or equal to 90° in which the intermediate portion (33) extends at least partially. Heating body (1) according to one of Claims 1 or 2, in which the first rectilinear termination (31) and the second rectilinear termination (32) of at least one of the heating elements (3) are separated by a angular sector with an angle α greater than or equal to 360° in which the intermediate portion (33) extends at least partially. Heating body (1) according to any one of the preceding claims, in which the plurality of heating elements (3) are arranged so that at least a part of the first rectilinear terminations (31) fall within a first circle (310) in the first base (11) and/or at least part of the second straight ends (32) of the heating elements (3) fits into a second circle (320) in the second base (12). Heating body (1) according to any one of the preceding claims, in which the heating elements (3, 43, 53) are arranged according to a first sub-assembly (4) and according to a second sub-assembly (5), the first sub-assembly (4) delimiting a first volume (400) in which the heating element(s) (3, 53) of the second sub-assembly (5) extend(s). Heating body (1) according to the preceding claim, in which the heating element(s) (3, 53) of the second sub-assembly 5 delimit(s) a second volume (500), the first volume (400) of the first sub-assembly (4) and the second volume (500) of the second sub-assembly (5) being concentric. Heating body (1) according to any one of the preceding claims, in which the intermediate portion (33) of at least one of the heating elements (3) is of helical shape. Heating body (1) according to any one of Claims 1 to 4, in which the intermediate portion (33) of at least one of the heating elements (3) comprises at least a first part (37) and a second part (38) respectively characterized by a first winding direction and a second winding direction around an extension axis (3000, 710, 720, 735) of the heating element passing through centers (36) of a section of a free end of the first rectilinear termination (31) and of a section of a free end of the second rectilinear termination (32) of the heating element (3, 41, 51, 61) considered, the first winding direction and the second winding direction being opposite. Heating body (1) according to the preceding claim, in which the intermediate portion (33) of at least one heating element (3) comprises an intermediate segment (39) arranged between the first part (37) and the second part (38 ), the intermediate segment (39) being closer to the main axis (100) of the heating body (1) than the first part (37) or the second part (38). Device (2) for electric heating of a heat transfer liquid (FC) comprising a casing (81) which delimits an internal volume (800) in which extends a heating body (1) according to any one of the preceding claims, the internal volume (800) being divided into at least:

• a first cavity (801) delimited by at least a first end wall (811) of the casing (81) and the first base (11) of the heating body (1) and in which the first terminations extend at least partially straight lines (31) of the heating elements (3),
• a heat transfer liquid (FC) circulation chamber (803) bordered by the first base (11) and the second base (12) and in which the heating elements (3) of the heating body (1) mainly extend;
• a second cavity (802) delimited by a second end wall (812) of the casing (81) and by the second base (12) of the heating body (1) and in which the second rectilinear terminations extend at least partially (32).