WO2018142063A1

WO2018142063A1 - Electric heater frame comprising stiffening ribs

Info

Publication number: WO2018142063A1
Application number: PCT/FR2018/050220
Authority: WO
Inventors: Pascal FOURGOUS
Original assignee: Valeo Systemes Thermiques
Priority date: 2017-02-01
Filing date: 2018-01-31
Publication date: 2018-08-09
Also published as: FR3062344B1; FR3062344A1

Abstract

The invention relates to a frame (2) of an electric heater (10) for heating a flow of air circulating inside a motor vehicle heating, ventilation and/or air conditioning system, said frame (2) comprising at least one heating compartment (6) having at least one recess (8, 80, 81) or a plurality of recesses intended to accommodate at least one heating element (5). According to the invention, the frame (2) comprises a plurality of stiffening ribs (7), all of the stiffening ribs (7) extending, in their entirety, in their respective recesses (8, 80, 81).

Description

FRAME FOR AN ELECTRIC HEATING DEVICE COMPRISING RIGIDIFI CATION RIBS

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

The heating of the air for heating the passenger compartment of a motor vehicle with a heat engine, as well as demisting and defrosting of the glazed surfaces, is ensured by heat exchange between a flow of air and a circulating fluid. in a heat exchanger. At the start of the engine and for a certain period following the start-up time, the calories transported by the fluid are insufficient to ensure a rapid and efficient heating of the passenger compartment. This is observed more particularly with certain types of engine and has a disadvantage in cold weather, because not only the internal temperature of the passenger compartment can be raised quickly, but also demisting and defrosting functions can not be ensured effectively.

To remedy these drawbacks, it has been proposed to mount an additional electrical 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 heating resistive elements are mounted, for example positive temperature coefficient (PTC) resistors, and radiant elements increasing the heat exchange surface with the flow of air passing through the heater. These different elements are assembled so as to form at least one heating element, the heating element (s) constituting the heater being then inserted into a housing thereof.

Such an electric heater is likely to be subjected to vibration when the vehicle is traveling. Such vibrations can cause embrittlement or even contribute to mechanical failure of the heating elements. In this context, the invention aims to provide an alternative to the known frames of additional electric heating devices, which is at least as effective, more rigid while being lightened, for less cost and simplified assembly.

The invention proposes for this purpose a frame of a device for electric heating of a flow of air circulating inside a ventilation, heating, and / or air-conditioning system of a motor vehicle, said frame comprising at least one heating compartment having a housing or several housings for receiving 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 a dwelling.

In other words, the stiffening ribs are located only at 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 a 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, so that the total number of stiffening ribs present on the frame is reduced compared to to a frame of the prior art. Therefore, less raw material is required for the manufacture of a frame according to the invention, it is found lightened and cheaper to manufacture compared to a frame of the prior art.

The frame of the electric heating device of an air flow according to the invention may further comprise 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 ribs stiffening extends, in its entirety, in the housing and between the at least two walls. In other words, the walls defining a housing integrally delimit, or 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 edge; vertical end being opposed 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 can maintain and strengthen the longitudinal walls of the housing in case of vibration. The ribs also prevent any displacement of the heating element inside the housing and can serve as a guide during the insertion of the heating element in 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 inner face of the longitudinal wall, the inner face of the longitudinal wall being the face intended to come into contact with the heating element when it is in the housing. Thus, the stiffening ribs are flush with the face of the vertical end edge. If the housing comprises 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 the same vertical end edge of the longitudinal wall. .

each stiffening rib comprises at least one curved arm. By curve is meant that the arm has a form of nonlinear equation, this equation being for example a sinusoid. each stiffening rib has a main elongation direction comprising a longitudinal component. In other words, each rib extends obliquely with respect 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 stiffening ribs comprises at least two curved arms intersecting.

- Curved arms intersect at 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 comprises at least one element for resistance to the flow of air.

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

- The frame has an alternation of housing and elements of resistance to air.

the frame comprises elements of resistance to the flow of air located on both sides of a housing.

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

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

- The frame comprises at least one flow resistance element of Γ located between several housings. at least one element for resistance to the flow of air is located between the longitudinal wall of a first housing and the longitudinal wall of a second housing.

the airflow resistance element comprises openings. - The openings are circular. These circular openings are, for example, obtained by perforation.

the element for resistance to the flow of air 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 comprises a protruding extension with respect to a front face or a rear face of the frame. Such a protruding 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 plastic deformation means allows to flatten 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' free of elastic elements capable of vibrating and generating noise inside the installation.

The plastic deformation means is distinguished from a guide rail in 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 for receiving the heating element. More particularly, the deformation means is in the path of the heating element during its insertion in the dwelling.

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 lateral face of the heating element and a longitudinal wall defining the housing.

- The plastic deformation means is configured to compress the heating element, plastically and irreversibly, in the direction of the wall opposite to the longitudinal wall on which the plastic deformation means is located.

Other features and advantages of the present invention will emerge more clearly from the description and the drawings, among which:

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

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

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

FIG. 4 is a view of the front face of the frame of FIG. 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 according to different perspectives; and FIGS. 8A and 8B are perspective views of the heating device of FIG. 1, respectively on the front face and on the rear face of the heating device.

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

In the following description, reference will be made to an orientation as a function of the longitudinal axes L, vertical V and transverse T, as arbitrarily defined by the trihedron L, V, T shown in the figures. The longitudinal axis L corresponds to the direction of extension of the frame. The choice of designations of these axes is not limited to the orientation that can take the heating device in its application to a motor vehicle. The additional heating device according to the invention is able to be housed in an air circulation duct of a ventilation, heating and / or air conditioning installation, so as to convert the electrical energy taken from the vehicle into thermal energy. restituted in the air passing through this conduit. 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, consisting in particular of heat sinks 3 and of electrodes 40, between which are arranged PTC effect stones 4 (for Positive Temperature Coefficient), so that the heating elements 5 are able to convert 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 housing for the heating elements 5, and a connection interface 12 arranged at one end of the frame 2 for connecting the additional heating device 10 to an electrical network of the vehicle for supplying the heating elements 5.

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

Each heating element 5 comprises heating resistive elements, for example positive temperature coefficient (PTC) resistors 4, as well as radiant elements 53 increasing the heat exchange surface with the flow of air passing through the heating device 10. The resistors with positive temperature coefficient 4 can be stuck directly on the radiant elements 53. The heating elements 5 are inserted in 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 housing 81. The housings 8, 80, 81 are closed at a first longitudinal end by a bottom wall 35 and to the opposite end by the connection interface 12 when it is attached to the heating compartment 6. The bottom wall 35 and the connection interface 12 delimit the housing in planes defined by the transverse axis T and vertical axis V.

The bottom wall 35 comprises elastic elements 16, here in the form of hooks. These elastic elements 16 may be metallic or plastic and are configured to push the heating elements when they are inserted into the housing and constrain the elastic elements: this ensures a good positioning of the heating elements 5 vis-à-vis of the connection interface 12, by avoiding the manufacturing tolerances of the frame 2 and the heating elements 5.

Without limitation, the frame 2 may be monobloc, 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 bottom wall 35 and the connection interface 12 is rendered secured to the heating compartment 6 to close the frame 2, and more specifically by closing the insertion holes 15 of the frame 2 through which the heating elements 5 are inserted beforehand. Alternatively, the frame 2 is made of 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 are 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 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 edge, also called the vertical end edge 33, 34, a notch forming a recess 37. This recess 37 allows removal of the material to lighten the heating device 10 without weakening it.

The housing 8, 80, 81 may have variable sizes depending on the distance between the longitudinal walls 31, 32 delimiting. As shown in FIG. 2 or 4, here all the housings 80, 81 have an identical width A1, along the transverse axis T. Here, each of the housings 8, 80, 81 is sized to receive a heating element 5 comprising two suitable means exchanging heat such as radiant elements 53 (Figure 1, 8 A, 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 with respect to a front face 61 and / or a rear face 62 of the frame. In the case shown, the prominent extension 38 is present both on the front face 61 and on the rear face 62 of the frame 2 or the heating device 10. Such prominent extension 38 then forms a protruding ridge on at least one sides of the frame, which allows to distribute the air flow over the entire frame 2 or the device of heating 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 for irreversibly deforming the heating element 5 when it is inserted into the housing. For this, the plastic deformation means 13 protrude from the longitudinal wall 31, 32 towards the inside 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 throttling. As a result, the heating element 5 is constrained during the passage at this constriction and 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 radiating 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 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 maintaining the heating element 5 in its housing 8, 80, 81 and prevent any displacement of the heating element.

The plastic deformation means 13 differs from a guide rail 14 in 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 for receiving the heating element 5. More particularly, the deformation means 13 is in the path of the heating element 5 when inserted in the housing 8, 80, 81, on the inner 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 taking into account the rib chains of the heating elements 5 and the dimensions of the housings 8, 80, 81 are counted. More precisely, 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 may extend partially or entirely from a vertical end edge 33 to an opposite vertical end edge 34 of the walls longitudinal 31, 32. These two edges 33, 34 define vertically the inner 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 may have a height identical to the height H1, H2 of the longitudinal wall 31, 32 on which it is located. The heights H 1, H 2 extend along the vertical axis V, as can be seen in FIG. 2 or 3, the height H 1 representing the maximum height of the longitudinal wall 31, 32 and the height H 2 representing the height of the longitudinal wall 31, 32 in the recess 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 greater the the heating element 5 is constrained in its housing 8, 80, 81.

The figures show that all the longitudinal walls 31, 32 comprise several plastic deformation means 13. The plastic deformation means 13 arranged projecting from the first longitudinal wall 31 are situated respectively on the same transverse axis T as the plastic deformation means 13 arranged in projection of the second longitudinal wall 32. In other words, the plastic deformation means 13 are arranged face to face, a 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 an end edge vertical 33, 34 to the other.

Of course, several different arrangements of plastic deformation means 13 are possible. Indeed, these arrangements may differ in size, number and / or position of the plastic deformation means 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 accommodation. 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 allow to avoid any displacement 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 in its housing 8, 80, 81, such that will be described below.

It should be noted that the stiffening ribs 7 extend in the illustrated embodiment of 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 transversely cover the housing 8, 80, 81 from one edge to the other. According to an alternative embodiment here not illustrated, 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 in a curved manner in the housing and is taken up at its opposite end on the same first longitudinal wall. Likewise, a rib of stiffening extending partially transversely in the housing 8, 80, 81 may extend from a first longitudinal wall 31 to the bottom wall 35. Whether 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 the 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 located 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 facing the heating element 5 when it is 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 of the vertical end 33, 34. The first vertical end edge 33 is for example merged with the rear face 62 of the heating device 10 or the frame 2 and the second vertical end edge 34 coincides 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 large enough to stiffen the walls longitudinal 31, 32 defining the housing 8, 80, 81 and the heating compartment

6 and on the other hand sufficiently small not to interfere with the heating element 5 when inserted into the housing 8, 80, 81. Specifically, the stiffening rib

7 can be flush with the heating element 5 then acting as a guide during the insertion of the heating element 5 in 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 alternating ribs on the front face 61 and the rear face 62 of the frame contributes to the good guidance 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 more to achieve the stiffening of the housing 8, 80, 81 and this arrangement alternately ribs 7 on the edges of vertical end 33, 34 can equally well be applied to the peripheral housing 81.

A particular arrangement of the ribs 7 in a housing 8, 80, 81 can be observed at the peripheral housing 81, in which two ribs 7 are arranged between the longitudinal walls 31, 32 defining the 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 housing 81 are present on a single face of the heating device 10 or 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 with respect to the frame 2. Indeed, 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, from one housing 8, 80, 81 to the other. 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 dwellings 81, a neighboring rib is disposed in the vicinity of the rear face 62 of the frame 2, in the central housing 80, and a rib is disposed in the vicinity of the front face 61 of the frame 2 again, in the other peripheral dwelling. Each stiffening rib 7 comprises at least one curved arm 70. By curve is meant that the arm 70 has a form of non-linear equation, this equation may for example be a sinusoid.

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

Several arrangements of the curved arms 70 are possible. According to a first exemplary 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 contiguous to one end of another curved arm 70, in particular at a longitudinal wall 31, 32 and more precisely at the same edge. 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 contiguous to each other. Such a rib 7, comprising two curved arms 70 placed end to end, extends in the same plane.

According to a second exemplary embodiment, the stiffening rib 7 comprises at least two curved arms 70 crossing one another. According to this example, the two curved arms 70 intersect at their center thus forming a cross. More precisely, 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 comprises both ribs 7 made according to the first embodiment and the second embodiment. Preferably, the ribs 7 according to the first embodiment are made in the peripheral housing 81 and the ribs 7 according to the second embodiment are made in the central housing 80. This arrangement has an orientation particular so that the frame 2 comprises a symmetry in the arrangement of all the 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 longitudinal walls 31, 32.

More precisely, 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 allow delimiting on both sides a path for insertion of the heating element 5. A recess 79 located 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 5 allows first, to leave free a space for accommodating 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 can Having a height greater than the height of the radiant elements 53. Secondly, this space above the heating element 5 allows the 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 the notch forming the recess 37 in the longitudinal wall 31, 32.

In addition to the stiffening ribs 7, the frame 2 comprises 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 rail of 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 according to 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 inner face of the guide rail 14 extends in the same plane as the inner face of the base 78 of the curved arm 70, an inner 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 recess, the guide rail is reduced in thickness 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 may 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 according to FIG. 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. 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 hole 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 rectilinearly and perpendicularly to the inner face 36 of the longitudinal walls 31, 32. Specifically, a stiffening bar 11 differs from a stiffening rib 7 in the sense that its direction of main lengthening does not include a longitudinal component. Rigidizing ribs 7 can cross the stiffening bars 11 to improve the recovery of forces opposite the insertion hole 15 of the heating elements 5. More precisely, the ribs 7 in sinusoid cross the stiffening bars 11.

Furthermore, the frame 2 comprises at least one airflow resistance element 9 located between a housing 8, 80, 81 and an edge 20 of the frame 2 or between two housing 8, 80, 81 adjacent. More specifically, at least one of the airflow resistance elements 9 is located between the first longitudinal wall 31 of a peripheral housing 81 located as close as possible to an end 20 of the frame 2 and an edge of the frame. 2 located at this end 20, and one of the elements of resistance to the flow of air 9 is located 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 airflow resistance elements 9 may have variable sizes depending on the distance separating the walls 31, 32 of two adjacent housings or as a function of 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 elements of resistance to the flow of air 9 having substantially the same length, measured along the longitudinal axis. One of these airflow resistance elements 9 has a width B2 smaller than a width B1 of the other elements of resistance to the flow of air 9, the width B1, B2 being measured according to FIG. transverse axis T (FIG. 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 much resistance to the flow of air, the element 9 comprises openings 90. These openings 90 are delimited by edges that can take any shape. In the exemplary embodiment, the edges defining the openings define a rectangular shape, so that the air flow resistance element 9 takes the form of a finned 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 flow of air passing through the openings 90 formed in the elements of resistance to the flow of air 9. Indeed, by placing the stiffening ribs 7 only in the housing 8, 80, 81, the latter, extending in full in one and / or the other housing 8, 80, 81, do not come s extend over the airflow resistance elements 9 and thus do not disturb the flow of air passing through the openings 90, that the airflow 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 particular relation with Figures 8 A and 8B.

At first, the heating elements 5 are inserted in 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 housing 8, 80, 81 helps to slide the heating elements 5 in translation towards the bottom wall 35, in particular in the direction shown by an arrow I. Thus, the stiffening ribs 7 provide 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 precisely, the recess 79 of the stiffening ribs make it possible to define the insertion path of the heating elements 5. The bars 11 and the guide rails 14 also contribute to ensuring a good trajectory of the heating element 5 in the housing 8, 80, 81. At the passage 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, are strangled or deformed by the plastic deformation means 13. The rigidity upper plastic deformation means 13 vis-à-vis the rigidity of the heating elements 5 plastically deforms and irreversibly the heating element 5 inserted. The lateral faces 50 of the heating elements 5 turned towards the plastic deformation means 13 undergo in particular compression 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 bear against the elastic elements 16 of the bottom wall 35 as a function of 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 that has been in contact with the plastic deformation means 13. More precisely, the deformation is of a 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 by both the plastic deformation means 13 and the opposite wall or the plastic deformation means 13 opposite thus avoiding any existing game. 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 disposed at one end of the heating compartment 6 and allows the connection of the heating device electrical 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 system. The foregoing description clearly explains how the invention makes it possible to achieve the objectives that it has set itself and in particular to propose a reinforced heating device while being lightened, which generates lower manufacturing costs.

Claims

1. Frame (2) of an electric heater (10) for a flow of air circulating inside a ventilation, heating and / or air-conditioning system of a motor vehicle, said frame (2) comprising at least one heating compartment (6) having a housing (8, 80, 81) or several housings for receiving 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 the 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 formed integrally 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 housing

(8, 80, 81) without overlapping the at least one airflow 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) intersects 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).