FR3062344A1 - FRAME FOR AN ELECTRIC HEATING DEVICE COMPRISING RIGIDIFICATION RIBS - Google Patents

Abstract

The invention relates to a frame (2) for an electric heating device (10) for a flow of air flowing inside a ventilation, heating and / or air-conditioning system of a vehicle. automobile, said frame (2) comprising at least one heating compartment (6) having at least one housing (8, 80, 81) or more housing for receiving at least one heating element (5). According to the invention, the frame (2) comprises a plurality of stiffening ribs (7), all the stiffening ribs (7) extending respectively, in their entirety, in a housing (8, 80, 81).

Description

@ Holder (s): VALEO THERMAL SYSTEMS Simplified joint-stock company.

® Agent (s): VALEO THERMAL SYSTEMS.

® FRAME OF A RIGIDIFICATION HEATING DEVICE.

(57) The invention relates to a frame (2) of an electric heating device (10) of an air flow circulating inside a ventilation, heating and / or air conditioning installation d 'a motor vehicle, said frame (2) comprising at least one heating compartment (6) having at least one housing (8, 80, 81) or several housings intended (s) to receive at least one heating element (5).

According to the invention, the frame (2) comprises a plurality of stiffening ribs (7), all the stiffening ribs (7) extending respectively, in their entirety, in a housing (8, 80, 81).

ELECTRIC COMPRISING RIBS OF

The invention relates to electric heating devices, in particular for a ventilation, heating and / or air conditioning installation of a motor vehicle.

The heating of the air intended for heating the passenger compartment of a motor vehicle with an internal combustion engine, as well as for demisting and defrosting the glazed surfaces, is ensured by heat exchange between an air flow and a circulating fluid. in a heat exchanger.

When the engine starts and for a certain period of time following the start time, the calories transported by the fluid are insufficient to ensure rapid and efficient heating of the passenger compartment. This is observed more particularly with certain types of engine and has a drawback in cold weather, because not only the internal temperature of the passenger compartment cannot be raised quickly, but also the functions of demisting and defrosting cannot be effectively ensured.

To remedy these drawbacks, it has been proposed to mount an additional electric heating device in the air flow directed towards the passenger compartment.

Such an electric heating device generally comprises a frame having a heating body comprising a plurality of parallel conductive plates, between which are mounted resistive heating elements, for example resistors with positive temperature coefficient (PTC), and radiating elements increasing the heat exchange surface with the air flow passing through the heating device. These various elements are assembled so as to form at least one heating element, the heating element or elements constituting the heating body then being inserted into a housing thereof.

Such an electric heating device is liable to be subjected, when the vehicle is running, to vibrations. Such vibrations can cause embrittlement or even contribute to mechanical failure of the heating elements.

In this context, the invention aims to propose an alternative to known frames of additional electric heating devices, which is at least as effective, more rigid while being lightened, for a lower cost and simplified assembly.

To this end, the invention provides a framework for an electric heating device for an air flow circulating inside a ventilation, heating, and / or air conditioning installation of a motor vehicle, said frame comprising at least one heating compartment having a housing or several housings intended to receive at least one heating element, characterized in that the frame comprises a plurality of stiffening ribs, all the stiffening ribs extending respectively, in their entirety, in accommodation.

In other words, the stiffening ribs are located only at the level of a housing. If the frame has several housings, a first group comprising at least one rib is located in a first housing, a second group is located in a second housing and so on. The stiffening ribs do not extend beyond the housing in which they are located.

Such targeting of the location of the stiffening ribs in the housing (s) makes it possible to arrange the ribs at the points of the frame most likely to vibrate, thus the total number of stiffening ribs present on the frame is reduced compared to to a framework of the prior art. Therefore, less raw material is necessary for the manufacture of a frame according to the invention, it is therefore reduced and cheaper to manufacture compared to a frame of the prior art.

The frame of the electric heating device for an air flow according to the invention may also include one or more of the following characteristics, alone or in combination:

- a housing being delimited by at least two walls, at least one of the stiffening ribs extends, in its entirety, in the housing and between the at least two walls. In other words, the walls defining a housing delimit entirely, or from end to end, each rib present in this housing.

- for the same housing, a first stiffening rib extends from a first vertical end edge of one of the walls and a second stiffening rib extends from a second vertical end edge of the same wall, the first vertical end edge and the second vertical end edge being opposite to each other.

- a housing being delimited by a first longitudinal wall and a second longitudinal wall, the plurality of stiffening ribs extends from the first longitudinal wall to the second longitudinal wall. Such stiffening ribs make it possible to maintain and reinforce the longitudinal walls of the housing in the event of vibrations. The ribs also make it possible to avoid any movement of the heating element inside the housing and can serve as a guide during the insertion of the heating element into its housing.

- for the same housing, a first stiffening rib extends from a first vertical end edge of a longitudinal wall and a second stiffening rib extends from a second vertical end edge of the same longitudinal wall, the first vertical end edge and the second vertical end edge being opposite to each other. A vertical end edge is defined as being a surface perpendicular to the internal face of the longitudinal wall, the internal face of the longitudinal wall being the face intended to come into contact with the heating element when the latter is located in the housing. Thus, the stiffening ribs are flush with the face of the vertical end edge. If the housing includes an additional rib, it preferably extends from the same vertical end edge as the first rib. Thus the three ribs are arranged alternately in the same housing.

- for the same housing, a third stiffening rib extends from one of the vertical edges of the longitudinal wall and a fourth stiffening rib also extends from this same vertical end edge of the longitudinal wall .

- Each stiffening rib comprises at least one curved arm. By curve, we mean that the arm has a form of non-linear equation, this equation being for example a sinusoid.

- Each stiffening rib has a main direction of elongation comprising a longitudinal component. In other words, each rib extends obliquely to the longitudinal walls defining a housing, "oblique" being defined as neither parallel nor perpendicular.

- At least one of the stiffening ribs comprises at least two curved arms placed end to end.

- At least one of the stiffening ribs comprises at least two intersecting curved arms.

- the curved arms cross in their center.

- the curved arms forming the stiffening rib are made in one piece with the frame. More specifically, the stiffening rib is injection molded on the frame.

- the frame includes at least one element for resistance to air flow.

the ribs extend in their entirety in one and / or the other of the housings, without overlapping of the air resistance elements or of the at least one air flow resistance element .

- the frame has alternating housings and air resistance elements.

- the frame includes elements of resistance to the flow of air located on either side of a housing.

- an air flow resistance element is located between a housing and an edge of the frame.

- At least one air flow resistance element is located between the first longitudinal wall of a first housing located closest to one end of the frame and an edge of the frame located at said end.

- the frame comprises at least one element for resistance to the flow of air situated between several housings.

- at least one air flow resistance element is located between the longitudinal wall of a first housing and the longitudinal wall of a second housing.

- the air flow resistance element includes openings.

- the openings are circular. These circular openings are, for example, obtained by perforation.

- the air flow resistance element comprises a plate having openings, these openings making it possible to define several fins.

- The frame comprises at least one stiffening bar located at a longitudinal end of a housing.

- At least one stiffening bar crosses at least one stiffening rib.

- one of the longitudinal walls of a housing includes a protruding extension relative to a front face or a rear face of the frame. Such a prominent extension then forms a projecting edge on at least one of the faces of the frame.

- At least one of the walls forming the housing comprises at least one plastic deformation means configured to irreversibly deform a heating element. Thus, such a plastic deformation means makes it possible to press the heating element by deforming it in the direction of the wall opposite to that on which it is located, which has the effect of keeping the heating element in the housing while s freeing from elastic elements capable of vibrating and generating noise inside the installation.

The plastic deformation means is distinguished from a guide rail by the fact that it is intended to irreversibly deform the heating element. In other words, the plastic deformation means arranged on one of the walls of the housing is located in the housing intended to receive the heating element. More particularly, the deformation means is located in the path of the heating element when it is inserted into the housing.

The plastic deformation is for example a compression of the heating element.

The invention also relates to a heating device characterized in that it comprises a frame as defined above and at least one heating element disposed in a housing of the frame.

- Said plastic deformation means is located between a deformed side face of the heating element and a longitudinal wall defining the housing.

- the plastic deformation means is configured to compress the heating element, in a plastic and irreversible manner, in the direction of the wall opposite to the longitudinal wall on which the plastic deformation means is located.

Other characteristics and advantages of the present invention will appear more clearly with the aid of the description and the drawings, among which:

- Figure 1 is a front view of a heating device according to the invention, in which are made visible the front face of a frame and three heating elements housed in this frame;

- Figure 2 is a perspective view of the frame of the heating device of Figure 1 without the heating elements illustrating in particular its front face;

- Figure 3 is a detail of the frame illustrated in Figure 2, from a different perspective angle and without the heating elements;

- Figure 4 is a view of the front face of the frame of Figure 2;

- Figure 5 is a perspective view of the frame of Figure 2, illustrating in particular its rear face;

- Figures 6 and 7 are detail views of the frame of Figure 2 without the heating elements and illustrating in particular a stiffening rib and a guide rail from different perspectives;

- And Figures 8A and 8B are perspective views of the heating device of Figure 1, respectively on the front face and on the rear face of the heating device.

It should first of all be noted that the figures show the invention in detail in order to implement the invention, said figures can of course be used to better define the invention if necessary. However, it should be noted that these figures show only part of the possible embodiments according to the invention.

In the description which follows, reference will be made to an orientation as a function of the longitudinal axes L, vertical V and transverse T, as they are arbitrarily defined by the trihedron L, V, T represented in the figures. The longitudinal axis L corresponds to the direction of elongation of the frame. The choice of names for these axes is not limiting of the orientation that the heating device can take in its application to a motor vehicle.

The additional heating device according to the invention is capable of being housed in an air circulation duct of a ventilation, heating and / or air conditioning installation, so as to transform the electrical energy taken from the vehicle into thermal energy returned in the air passing through this duct. The installation is not shown here, but it will be understood that a main duct of this installation conventionally comprises an opening made in the wall for the insertion of the additional heating device.

The additional heating device 10 according to the invention, illustrated in particular in FIGS. 1, 8A and 8B, comprises a frame 2 and heating elements 5, constituted in particular by heat sinks 3 and electrodes 40, between which stones are arranged. with PTC effect 4 (for Positive Temperature Coefficient), so that the heating elements 5 are capable of transforming an electric current into thermal energy.

The additional heating device 10 is in particular arranged so that the frame 2 comprises at least one heating compartment 6, forming a receiving casing for the heating elements 5, and a connection interface 12 disposed at one end of the frame 2 for the connection of the additional heating device 10 to an electrical network of the vehicle for the supply of the heating elements 5.

The heating compartment 6 has the shape of a rectangular parallelepiped, the two main faces of which, a front face 61 and a rear face 62, are perforated to allow the passage of air and a diffusion of heat in the duct where the heating device 10 is installed.

Each heating element 5 comprises heating resistive elements, for example resistors with a positive temperature coefficient (PTC) 4, as well as radiant elements 53 increasing the heat exchange surface with the air flow passing through the heating device 10. The resistors with a positive temperature coefficient 4 can be bonded directly to the radiant elements 53. The heating elements 5 are inserted into housings 8 formed inside the heating compartment 6.

The heating compartment 6 here comprises three housings 8, among which one can define a central housing 80 and two peripheral housings 81. The housings 8, 80, 81 are closed at a first longitudinal end by a bottom wall 35 and at the opposite end by the connection interface 12 when the latter is attached to the heating compartment 6. The bottom wall 35 and the connection interface 12 delimit the housings according to planes defined by the transverse axis T and the vertical axis V.

The bottom wall 35 comprises elastic elements 16, here in the form of hooks. These elastic elements 16 can be metallic or plastic and are configured to repel the heating elements when these are inserted into the housings and constrain the elastic elements: this makes it possible to ensure correct positioning of the heating elements 5 vis-à-vis of the connection interface 12, bypassing the manufacturing tolerances of the frame 2 and the heating elements 5.

Without limitation, the frame 2 can be in one piece, that is to say made in one piece. The heating elements 5 are then inserted along the longitudinal axis L in the direction of the wall of the bottom 35 then the connection interface 12 is made integral with the heating compartment 6 in order to close the frame 2, and more precisely by closing orifices of insertion 15 of the frame 2 through which the heating elements 5 are inserted beforehand. Alternatively, the frame 2 is produced in two shells, with the first shell comprising the front face 61 of the frame 2 and the second shell comprising the rear face 62 of the frame 2. In this case, the direction of insertion of the heating elements 5 can be the same as before or follow the vertical axis V towards one of the two shells.

As can be seen in Figure 2, each housing 8, 80, 81 is defined by longitudinal walls 31, 32, here two in number, parallel to each other and among which there is a first longitudinal wall 31 and a second wall longitudinal 32, which define the longitudinal sides of the housing 8, 80, 81. According to this exemplary embodiment, the longitudinal walls 31, 32 extend at least along the entire length of the heating elements 5.

It should be noted that all or part of the longitudinal walls 31, 32 may have, on one of their edges, also called vertical end edge 33, 34, a notch forming a step 37. This step 37 makes it possible to remove material to lighten the heating device 10 without weakening it.

The housings 8, 80, 81 can have variable sizes as a function of the distance separating the longitudinal walls 31, 32 defining it. As shown in FIG. 2 or 4, here all the housings 80, 81 have an identical width Al, along the transverse axis T. Here, each of the housings 8, 80, 81 is dimensioned to receive a heating element 5 comprising two suitable means to exchange heat such as radiant elements 53 (Figure 1, 8A, 8B).

Furthermore, as can be seen in FIGS. 2, 5, 8A and 8B, at least one of the longitudinal walls 31, 32 of one of the housings 8, 80, 81 comprises a protruding extension 38 relative to a front face 61 and / or a rear face 62 of the frame. In the case shown, the protruding extension 38 is present both on the front face 61 and on the rear face 62 of the frame 2 or of the heating device 10. Such a protruding extension 38 then forms a projecting edge on at least one of the faces of the frame, which makes it possible to distribute the air flow over the entire frame 2 or the heating device 10 by guiding it.

At least one of the longitudinal walls 31, 32, forming the housing 8, 80, 81 comprises at least one plastic deformation means 13 intended to irreversibly deform the heating element 5 during its insertion into the housing. For this, the plastic deformation means 13 projects from the longitudinal wall 31, 32 towards the interior of the housing 8, 80, 81 so as to reduce the space allocated for the heating element 5 in the housing 8. , 80, 81 corresponding and form a constriction. It follows that the heating element 5 is constrained during the passage at the level of this constriction and that the plastic deformation means 13 generates a plastic deformation of the heating element 5. More precisely, in order to generate this plastic deformation, the means deformation 13 has a rigidity greater than the rigidity of the heating element 5 and more particularly of the radiant element 53. Thus, it is ensured that only the heating element 5 is deformed while the plastic deformation means 13 and the walls longitudinal 31, 32 of the frame 2 remain intact.

Such a plastic deformation means 13 thus makes it possible to press the heating element 5 into its housing 8, 80, 81 by deforming it in the direction of the longitudinal wall 31, 32 opposite to that on which the deformation means 13 is located. This irreversible deformation has the effect of keeping the heating element 5 in its housing 8, 80, 81 and of preventing any movement of the heating element.

The plastic deformation means 13 is distinguished from a guide rail 14 by the fact that it is intended to irreversibly deform the heating element 5. In other words, the plastic deformation means 13 arranged on one of the walls of the housing 31, 32, 35 is located inside the housing 8, 80, 81 intended to receive the heating element 5. More particularly, the deformation means 13 is located in the trajectory of the heating element 5 during its insertion in the housing 8, 80, 81, on the internal face 36 of the walls. The plastic deformation is for example a compression of the heating element 5.

The plastic deformation means 13 has a maximum thickness, measured along the transverse axis T. This maximum thickness has been fixed by taking π

account of the rib chains of the heating elements 5 and of the dimensions of the housings 8, 80, 81. More specifically, the maximum thickness of the plastic deformation means 13 is at least equal to the difference between the width Al of the housing 8, 80, 81 and the width of the heating element 5.

It should be noted that the plastic deformation means 13 can extend partially or entirely from a vertical end edge 33 to an opposite vertical end edge 34 of the longitudinal walls 31, 32. These two edges 33, 34 vertically delimit the internal face 36 of the longitudinal wall 31, 32 on which the plastic deformation means 13 is located. In other words, the plastic deformation means 13 can have a height identical to the height H1, H2 of the longitudinal wall 31, 32 on which it is located. The heights Hl, H2 extend along the vertical axis V, as can be seen in FIG. 2 or 3, the height Hl representing the maximum height of the longitudinal wall 31, 32 and the height H2 represents the height of the longitudinal wall 31, 32 in the offset zone 37. The dimension of the plastic deformation of the heating element 5 then depends on the height of the plastic deformation means 13. In general, the larger the dimension of the plastic deformation, the more the heating element 5 is constrained in its housing 8, 80, 81.

The figures show that all of the longitudinal walls 31, 32 include several plastic deformation means 13. The plastic deformation means 13 projecting from the first longitudinal wall 31 are respectively located on the same transverse axis T as the plastic deformation means 13 arranged projecting from the second longitudinal wall 32. In other words, the plastic deformation means 13 are arranged face to face, from one longitudinal wall 31, 32 to the other. It should be noted, in this embodiment, that the plastic deformation means 13 have the same dimensions.

Each plastic deformation means 13 has a free end face 130. This free end face 130 is located in the housing 8, 80, 81. The free end face 130 here has a rounded shape, namely a face curved and without edges. The deformation means 7 takes, for example, the shape of a boss having the shape of a cylinder portion extending from one vertical end edge 33, 34 to the other.

Of course, several different arrangements of the plastic deformation means 13 are possible. Indeed, these arrangements can differ by the size, the number and / or the position of the plastic deformation means (s) 13.

According to the invention, the frame 2 comprises a plurality of stiffening ribs 7, and all the stiffening ribs 7 extend respectively, in their entirety, in a housing 8, 80, 81. In other words, the stiffening ribs 7 are located only at at least one of the housings 8, 80, 81. Here, each housing 8, 80, 81 comprises a plurality of stiffening ribs 7 each extending in their entirety in this housing 8, 80, 81 By "integrality" is meant that the rib extends from its first end to its second end in the same housing. In other words, the stiffening ribs 7 do not extend beyond the housing 8, 80, 81 in which they are located.

These stiffening ribs 7 make it possible to stiffen the heating compartment 6, and more precisely each housing 8, 80, 81, without penalizing the release of heat by not completely closing each housing 8, 80, 81. The stiffening ribs 7 also make it possible to avoid any deflection of the heating element 5 inside the housing 8, 80, 81 and can serve as a guide during the insertion of the heating element 5 into its housing 8, 80, 81, as as will be described below.

It should be noted that the stiffening ribs 7 extend in the illustrated embodiment from a first longitudinal wall 31 to a second longitudinal wall 32, or vice versa. By this is meant that each stiffening rib 7 is intended to cover the housing 8, 80, 81 transversely from one edge to the other. According to a variant embodiment not shown here, it can be envisaged that at least one stiffening rib extends partially transversely in the housing 8, 80, 81, that is to say that it originates in a first wall longitudinal, extends curved in the housing and comes to resume at its opposite end on the same first longitudinal wall. Similarly, a stiffening rib extending partially transversely in the housing 8, 80, 81 may extend from a first longitudinal wall 31 to the bottom wall 35. That the overlap by the stiffening ribs 7 is total or partial, it is constant according to the invention that the ribs 7 extend only in the housing, that is to say that they do not extend transversely beyond the longitudinal walls 31, 32 participating in defining housing 8, 80, 81.

In FIG. 2, it should be noted that for the same housing, here the central housing 80, at least one first stiffening rib 71, extends from a first vertical end edge 33 of the first longitudinal wall 31 towards the first vertical end edge 33 of the second opposite longitudinal wall 32 and a second stiffening rib 72 extends from a second vertical end edge 34 of the first longitudinal wall 31, towards the second edge vertical end 34 of the second opposite longitudinal wall 32, the first vertical end edge 33 and the second vertical end edge 34 being opposite to each other. Thus, it is understood that the first rib 71 and the second rib 72 extend in parallel planes situated vertically on either side of the central housing 80, with the first rib 71 located on the rear face 62 of the frame 2 and the second rib 72 located on the front face 61 of the frame 2.

As is more visible in FIG. 3, the vertical end edge 33, 34 is defined as being a surface perpendicular to the internal face 36 of the longitudinal wall 31, 32, the internal face 36 of the longitudinal wall 31, 32 being the face turned towards the heating element 5 when the latter is located in the housing 8, 80, 81. Thus, the stiffening ribs 7 are flush with the vertical end edge 33, 34 and more precisely the face forming the edge d vertical end 33, 34. The first vertical end edge 33 is for example coincident with the rear face 62 of the heating device 10 or the frame 2 and the second vertical end edge 34 is coincident with the front face 61 of the heater 10 or frame 2.

In general, the stiffening rib 7 has a height, measured along the vertical axis V. The stiffening rib 7 extending from a vertical end edge, its height defines a space in the housing 8, 80, 81 This height is on the one hand sufficiently large to stiffen the longitudinal walls 31, 32 defining the housing 8, 80, 81 and the heating compartment and on the other hand sufficiently small not to interfere with the heating element 5 during its insertion into the housing 8, 80, 81. More specifically, the stiffening rib can be flush with the heating element 5 then playing a role of guide during the insertion of the heating element 5 into the housing 8, 80, 81.

In the central housing 80, a third stiffening rib 73 extends between the first vertical end edges 33 of the longitudinal walls 31, 32. Thus, the third rib 73 extends in the same plane as the first rib 71. This arrangement of the ribs alternately on the front face 61 and the rear face 62 of the frame contributes to the correct guiding of the heating element 5 during its insertion into the housing 8, 80, 81. Of course, the number of stiffening ribs 7 per housing 8, 80, 81 is not limiting, there could be as many ribs 7 as necessary or even more to achieve the stiffening of the housing 8, 80, 81 and this arrangement alternately of the ribs 7 on the edges d the vertical end 33, 34 can just as easily be applied to the peripheral housings 81.

A particular arrangement of the ribs 7 in a housing 8, 80, 81 can be observed at the level of the peripheral housings 81, in which two ribs 7 are arranged between the longitudinal walls 31, 32 defining this peripheral housing 81, the two ribs 7 being arranged at the same vertical end edge 33, 34. Thus, a fourth stiffening rib 74 extends from the second vertical end edge 34 of the longitudinal wall 31, 32 and a fifth stiffening rib 75 also extends from this second vertical end edge 34 of the longitudinal wall 31, 32. In other words, the ribs 7 of the peripheral housings 81 are present on a single face of the heating device 10 or of the frame 2.

With these different arrangements of the ribs 7 on the frame 2, it is noted that a second alternation exists. This second alternating arrangement is located transversely relative to the frame 2. In fact, there is an alternation of the position of the ribs 7 at the front face 61 and the rear face 62 of the frame 2 on the same transverse axis, c 'that is to say from one housing 8, 80, 81 to another. In other words, transversely, a rib is disposed in the vicinity of the front face 61 of the frame

2, in one of the peripheral housings 81, a neighboring rib is arranged in the vicinity of the rear face 62 of the frame 2, in the central housing 80, and a rib is arranged in the vicinity of the front face 61 of the frame 2 again, in the other peripheral housing.

Each stiffening rib 7 comprises at least one curved arm 70. By curve, it is meant that the arm 70 has a form of non-linear equation, this equation can for example be a sinusoid.

Each curved arm 70 has a first end 76 and a second end 77. The first end 76 is located on the first longitudinal wall 31 and the second end 77 is located on the second longitudinal wall 32.

Several arrangements of the curved arms 70 are possible. According to a first embodiment, the stiffening rib 7 comprises at least two curved arms 70 placed end to end. One of the ends of one of the curved arms 70 is then joined to one of the ends of another curved arm 70, in particular at the level of a longitudinal wall 31, 32 and more precisely at the same edge of vertical end 33, 34. The two curved arms 70 are placed end to end so as to form a complete period of sinusoid. In other words, the curved arms 70 are symmetrical with respect to a transverse axis T1 passing through their ends 76, 77 joined together. Such a rib 7, comprising two curved arms 70 placed end to end, extends in the same plane.

According to a second embodiment, the stiffening rib 7 comprises at least two intersecting curved arms 70. According to this example, the two curved arms 70 cross at their center thus forming a cross. More specifically, the cross comprises an axis of symmetry coincident with a transverse axis T2 passing through the point of intersection between the two curved arms 70.

The frame 2 includes both ribs 7 produced according to the first exemplary embodiment and the second exemplary embodiment. Preferably, the ribs 7 according to the first embodiment are made in the peripheral housings 81 and the ribs 7 according to the second embodiment are made in the central housing 80. This arrangement has a particular orientation so that the frame 2 includes a symmetry in the arrangement of the set of ribs 7. Thus, seen from above and without perspective, the frame 2 comprises an axis of symmetry coincident with a longitudinal axis L1 passing through the center of the frame 2.

Preferably, the stiffening ribs 7 are molded by plastic injection on the frame 2. It is then understood that the curved arms 70 forming a stiffening rib 7 are made in one piece with the frame 2 and more precisely with the walls. longitudinal 31, 32.

More specifically, FIG. 6 illustrates a stiffening rib 7 extending between the two longitudinal walls 31, 32 of one of the peripheral housings 81. This point of view makes it possible to visualize that the curved arm 70 comprises a base 78 forming an extra thickness located at each junction between the curved arm 70 and one of the longitudinal walls 31, 32. In other words, the bases 78 are located at each end 76, 77 of the curved arm 70 and make it possible to delimit a path on either side of insertion for the heating element 5. A recess 79 situated between the two bases 78 of a curved arm 70 is intended to form a space above the heating element 5. This space above the element heater 5 allows, firstly, to leave free a space intended to accommodate a central zone of the heating element 5. More precisely this central zone of the heating element 5 corresponds to the electrodes 40 enclosing the CTP stones may have a greater height than the height of the radiant elements 53. Secondly, this space above the heating element 5 allows a release of heat from the heating element 5 in its immediate environment.

Furthermore, it should be noted that the recesses 37 of the longitudinal walls 31, 32 are located between two ribs 7 or on either side of a rib 37. Thus, the height of the rib 7 is substantially equal to the height of the notch forming the step 37 in the longitudinal wall 31, 32.

In addition to the stiffening ribs 7, the frame 2 includes guide rails 14 for guiding the heating element 5 when it is inserted into the housing. More specifically, each housing 8, 80, 81 comprises at least one guide rail 14. Each guide rail 14 extends from one of the vertical end edges 33, 34 of the longitudinal wall 31, 32 independently of the stiffening ribs 7, that is to say at a distance from these ribs 7.

In FIG. 7, a guide rail 14 is visible from a point of view taken inside the housing 8, 80, 81. The guide rail 14 is flush with the same longitudinal axis L2 as the stiffening rib 7. More precisely , the internal face of the guide rail 14 extends in the same plane as the internal face of the base 78 of the curved arm 70, an internal face being defined as a face located towards the interior of the housing 8, 80, 81. In other words, the guide rails 14 participate in defining the insertion path with the stiffening ribs 7.

When the guide rail 14 extends from one of the vertical edges 33, 34 in an offset, the guide rail is reduced in thickness so as to always be flush with the same longitudinal axis as the stiffening ribs 7.

As can be seen in FIGS. 2 to 5, the guide rails 14 can have different lengths, the length of the guide rails 14 being measured along the longitudinal axis L. The width of the guide rails 14, measured along the transverse axis, is substantially the same for all the guide rails 14.

Furthermore, the frame 2 comprises at least one stiffening bar 11. The stiffening bar 11 is preferably located at one end of the housing 8, 80, 81. In the various figures, and in particular in FIG. 5, it is possible to see that a bar 11 is present in each housing 8, 80, 81 on the side of the bottom wall 35 and on the front face of the frame 2, and that four bars 11 are located on the side of an insertion orifice 15 of the heating element 5. Each stiffening bar 11 extends only in the housing 8, 80, 81 and extends from one longitudinal wall 31, 32 to the other, along the transverse axis. In other words, each bar 11 extends in a rectilinear manner and perpendicular to the internal face 36 of the longitudinal walls 31, 32. More specifically, a stiffening bar 11 differs from a stiffening rib 7 in the direction in which its direction of main extension does not include a longitudinal component.

Rigidification ribs 7 can cross the stiffening bars 11 making it possible to improve the recovery of forces opposite the insertion orifice 15 of the heating elements 5. More specifically, the ribs 7 in sinusoid cross the bars of stiffening 11.

Furthermore, the frame 2 comprises at least one element for resisting the flow of air 9 situated between a housing 8, 80, 81 and an edge 20 of the frame 2 or between two adjacent housings 8, 80, 81. More specifically, at least one of the air flow resistance elements 9 is located between the first longitudinal wall 31 of a peripheral housing 81 located closest to one end 20 of the frame 2 and an edge of the frame 2 situated at this end 20, and one of the air flow resistance elements 9 is situated between the first longitudinal wall 31 of the central housing 80 and a second wall of a peripheral housing 81.

It should be noted that the air flow resistance elements 9 can have variable sizes depending on the distance separating the walls 31, 32 from two adjacent housings or depending on the distance separating the edge 20 of the frame and one of the walls 31, 32 of the housing 8, 80, 81. According to the embodiment shown in the figures, the frame 2 comprises four air flow resistance elements 9 having substantially the same length, measured along the longitudinal axis. One of these air flow resistance elements 9 has a width B2 smaller than a width B1 of the other air flow resistance elements 9, the width Bl, B2 being measured according to l 'transverse axis T (Figure 4). The dimensioning of these elements of resistance to the flow of air 9 depends, in particular, on the width of the desired frame.

In order not to completely block the installation and generate too great a resistance to the flow of air, the element 9 comprises openings 90. These openings 90 are delimited by edges which can take any shape. In the embodiment, the edges delimiting the openings define a rectangular shape, so that the air flow resistance element 9 takes the form of a fin bar. According to a variant, the edges delimiting the openings define a circular shape, the openings being able, for example, to be obtained by perforation in the material constituting the element for resistance to the flow of air 9.

It should be noted that according to the invention, the stiffening ribs 7 are configured so that they do not disturb the air flow passing through the openings 90 formed in the air flow resistance elements 9. Indeed, by placing the stiffening ribs 7 only in the housings 8, 80, 81, the latter, extending entirely in one and / or the other of the housings 8, 80, 81, do not come s extend over the air flow resistance elements 9 and therefore do not disturb the air flow passing through the openings 90, that the air flow resistance element 9 comprises openings 90 defining rectangular or circular shapes.

We will now describe the mounting of the additional heating device 10 comprising the frame 2 according to the invention in relation in particular to FIGS. 8A and 8B.

Firstly, the heating elements 5 are inserted into each of the appropriate housings 80, 81 inside the heating compartment 6. For this, the heating elements 5 are inserted through the orifices 15 formed in the frame

2. The presence of the stiffening ribs 7 at the level of the housings 8, 80, 81 helps to slide the heating elements 5 in translation towards the bottom wall 35, in particular in the direction materialized by an arrow I. Thus, the ribs of stiffening 7 perform a dual role by stiffening on the one hand the longitudinal walls 31, 32 defining the housing 8, 80, 81 and on the other hand by guiding the heating element 5 during its insertion. More specifically, the recesses 79 of the stiffening ribs make it possible to define the path for the insertion of the heating elements 5. The bars 11 and the guide rails 14 also participate in ensuring a good trajectory of the heating element 5 in the housing 8, 80, 81.

In passing of the plastic deformation means 13, the walls of the heating elements 5, in particular the faces of the radiant elements 53 facing the walls 31, 32, find themselves constricted or even deformed by the plastic deformation means 13. The higher rigidity of the means of plastic deformation 13 with respect to the rigidity of the heating elements 5 makes it possible to plastically and irreversibly deform the heating element 5 inserted. The lateral faces 50 of the heating elements 5 facing the plastic deformation means 13 undergo compression in particular in the direction of the longitudinal wall 31, 32 opposite to that on which the deformation means 13 is located.

At the end of insertion, each heating element 5 can come to bear on the elastic elements 16 of the bottom wall 35 depending on the manufacturing tolerances. In addition, the lateral face 50 of the heating element 5 facing the plastic deformation means 13 remains deformed over the entire portion having been in contact with the plastic deformation means 13. More precisely, the deformation is of substantially identical size to the thickness of the plastic deformation means 13 located directly upstream of the portion in question. In this position, the heating elements 5 are constrained in their housing both by the plastic deformation means 13 and by the opposite wall or the opposite plastic deformation means 13, thus making it possible to avoid any existing play. The heating elements 5 do not debate inside their housing 8, 80, 81.

Finally, once the heating elements 5 have been inserted, the heating compartment 6 is closed by the connection interface 12. The connection interface 12 is then placed at one end of the heating compartment 6 and allows the connection of the heating device. 10 to an electrical network of the vehicle. The heating device 10 is then inserted into a duct of the heating-ventilation and / or air-conditioning installation.

The foregoing description clearly explains how the invention makes it possible to achieve the objectives which it has set itself, and in particular to propose a reinforced heating device while being lightened, which generates lower manufacturing costs.

Claims (15)

1. Frame (2) of an electric heating device (10) of an air flow circulating inside a ventilation, heating, and / or air conditioning installation of a motor vehicle, said frame (2) comprising at least one heating compartment (6) having a housing (8, 80, 81) or several housings intended to receive at least one heating element (5), characterized in that the frame (2 ) comprises a plurality of stiffening ribs (7), all the stiffening ribs (7) extending, respectively, in their entirety, in a housing (8, 80, 81). 2. Frame according to the preceding claim, characterized in that a housing (8, 80, 81) being delimited by at least two walls (31, 32, 35), at least one of the stiffening ribs (7) extends , in its entirety, in the housing (8, 80, 81) and between the at least two walls. 3. Frame according to claim 1 or 2, characterized in that a housing (8, 80, 81) being delimited by a first longitudinal wall (31) and a second longitudinal wall (32), at least one of the stiffening ribs (7) extends from the first longitudinal wall (31) to the second longitudinal wall (32). 4. Frame according to the preceding claim, characterized in that, for the same housing, a first stiffening rib (7, 71) extends from a first vertical end edge (33) of a longitudinal wall (31, 32) and a second stiffening rib (7, 72) extends from a second vertical end edge (34) of the same longitudinal wall (31, 32), the first end edge vertical (33) and the second vertical end edge (34) being opposite to each other. 5. Frame according to claim 3 or 4, characterized in that, for the same housing (8, 80, 81), a third stiffening rib (7, 74) extends from one of the vertical edges (33 , 34) of the longitudinal wall (31, 32) and a fourth stiffening rib (7, 75) also extends from this same vertical end edge (33, 34) of the longitudinal wall (31, 32). 6. Frame according to any one of the preceding claims, characterized in that each stiffening rib (7) comprises at least one curved arm (70). 7. Frame according to the preceding claim, characterized in that at least one of the stiffening ribs (7) comprises at least two curved arms (70) placed end to end. 8. Frame according to claim 6 or 7, characterized in that at least one of the stiffening ribs (7) comprises at least two curved arms (70) intersecting. 9. Frame according to any one of claims 6 to 8, characterized in that the curved arms (70) forming the stiffening rib (7) are made in one piece with the frame (2). 10. Frame according to any one of the preceding claims, characterized in that it comprises at least one element for resistance to the flow of air (9). 11. Frame according to the preceding claim, characterized in that the stiffening ribs (7) extend in their entirety in one and / or the other of the housings (8, 80, 81), without covering the at least one air flow resistance element (9). 12. Frame according to any one of the preceding claims, characterized in that it comprises at least one stiffening bar (11) located at a longitudinal end of a housing (8, 80, 81). 13. Frame according to the preceding claim, characterized in that at least one stiffening bar (11) crosses at least one stiffening rib (7). 14. Frame according to any one of the preceding claims, characterized in that at least one of the walls (31, 32, 35) forming the housing (8, 80, 81) comprises at least one plastic deformation means (13) configured to irreversibly deform a heating element (5). 15. Electric heating device (10) characterized in that it comprises a frame (2) defined according to any one of the preceding claims and at least one heating element (5) disposed in a housing (8, 80, 81) of the frame (2). 1/8 ⁷ 13