WO2019158842A1

WO2019158842A1 - Frame for an electric heating device, comprising an elastically deformable element

Info

Publication number: WO2019158842A1
Application number: PCT/FR2019/050289
Authority: WO
Inventors: Frédéric PIERRON; Serif KARAASLAN; Pascal FOURGOUS; Yann COUAPEL; Romain DELCOURT; Laurent Tellier
Original assignee: Valeo Systemes Thermiques
Priority date: 2018-02-19
Filing date: 2019-02-11
Publication date: 2019-08-22
Also published as: FR3078021A1; FR3078021B1

Abstract

The invention relates to a frame (3) for an electric heating device (1) for heating an air flow circulating inside a ventilation, heating and/or air-conditioning system of a motor vehicle. The frame comprises at least one housing (7) intended to receive at least one heating element (5), said housing (7) being defined by a plurality of longitudinal and transverse walls (23, 25) forming a longitudinal insertion path for a heating element. According to the invention, at least one of the longitudinal and transverse walls (23, 25) of the housing (7) comprises a displacement reducing element (10) projecting from said wall and having a cross-dimension of the order of 1 to 2.5 millimetres.

Description

FRAME OF AN ELECTRIC HEATING DEVICE COMPRISING AN ELEMENT

DEFORMABLE ELAST1ALLY

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, as well as demisting and defrosting of the glazed surfaces, is ensured by heat exchange between an air flow and an engine coolant. circulating in a heat exchanger.

When starting the engine and for a certain period following the start-up time, the calories carried by the engine coolant are insufficient to ensure rapid and efficient heating of the air to be blown into 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 temperature. 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. For this purpose, the housing, defined by walls, comprises resilient elements formed of tabs inclined relative to the walls from which they are articulated, so as to be arranged in the housing and the insertion path during assembly of the 'heating element. These resilient tongues are thus constrained during the insertion of the heating element (s) and they then exert an elastic restoring force participating in the plating of the corresponding heating element towards the opposite wall of the housing. This ensures the reduction of movement of the heating element in its housing which must be provided with dimensions substantially greater than those of the heating element to allow its insertion. The disadvantage of using these elastic elements exerting a restoring force on the heating elements lies in the fact that during the rolling, or in case of fall of the heating device, the elastic elements are subjected to more vibrations or less important. These vibrations may cause a noise in the ventilation circuit serving the passenger compartment may cause discomfort for motor vehicle users. It is also possible that these vibrations weaken or even break the elastic elements, the heating elements are then no longer properly maintained in their housing, which can cause at least, again, a noise annoyance for users or contribute to mechanical failure 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, reliable.

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 housing for receiving at least one heating element, the housing being delimited by a plurality of longitudinal and transverse walls forming a longitudinal insertion path for a heating element. According to the invention, at least one of the longitudinal and transverse walls of the housing comprises a deflection reducing element projecting from said wall and having a transverse dimension of the order of 1 to 2.5 millimeters.

Thus, the invention provides an alternative for holding the heating elements in a heater. The presence of a deflection reducing element of small width relative to the width of the housing and therefore of the heating element implies a lower resistance of the displacement reduction element during the insertion of the heating element.

More particularly, it can be provided that the deflection reduction element has a transverse dimension, that is to say a dimension along an axis parallel to the main direction of the air flow brought to pass through the heating elements in the device heating, of the order of 1 to 2.5 millimeters. And it can be provided that the transverse dimension of the wall which carries said deflection reduction element is of the order of 8 to 18 millimeters. In these numerical examples, it is understood that the maximum ratio of the transverse dimensions of the displacement reduction element and the wall which carries it may be 5 to 6% for a displacement reduction element whose transverse dimension is 1 millimeter arranged on a wall whose transverse dimension is 18 millimeters. And that the minimum ratio of the transverse dimensions of the displacement reduction element and the wall which carries it can be of the order of 30% for a deflection reduction element whose transverse dimension is substantially equal to 2.5 millimeters arranged on a wall whose transverse dimension is substantially equal to 8 millimeters. More particularly, according to the invention, it is possible to provide a transverse dimension of the displacement reduction element of the order of 5 to 30% lower than the transverse dimension, along the same transverse axis, of the longitudinal and transverse wall. who wears it.

According to one or more characteristics that can be taken alone or in combination, it can be provided that:

- The deflection reduction element is arranged transversely so as to be centered substantially on the median longitudinal axis of the wall which carries it. In other words, the displacement reduction element is located on a median plane of the frame, and therefore the housing in which it extends. Thus, it is ensured, regardless of the width of the deflection reducing element, that the position of the heating element in the housing is balanced.

- The longitudinal and transverse walls defining the housing each comprise at least one displacement reduction element.

- At least one longitudinal and transverse wall comprises several displacement reduction elements. In this way, the heating element can be subjected to the mechanical stress of the displacement reduction elements in several places and its position in the housing all the more stable.

Several displacement reduction elements are aligned along the longitudinal and / or transverse direction of the wall which carries them.

- The insertion path is delimited longitudinally by a bottom wall which extends opposite an opening through which can be inserted the heating element intended to come into the housing, a direction of insertion being defined since opening to the bottom wall, and the deflection reducing element is in an area defined between the bottom wall and a central portion of the housing relative to its longitudinal dimension. It can be provided that the downstream end of the deflection reduction element is arranged at a longitudinal distance from the bottom wall of between 10 and 30 millimeters. In this way, the downstream end is sufficiently far from the bottom wall to allow, if necessary, a deformation of the portion of the displacement reduction element in contact with the heating element, while remaining in a reducing context. end of stroke travel insertion of the heating element, that is to say in the area where the heating element is most likely to debate. - The displacement reduction element is integral with the longitudinal wall on which the displacement reduction element is located. Such a configuration facilitates the manufacturing operations of the frame, the deflection reducing element can be obtained in the same frame molding operation for example.

- The deflection reduction element comprises a ramp extending progressively inwardly of the housing relative to the direction of insertion, in relation to the opposite longitudinal and transverse wall. In other words, the deflection reducing element protrudes from a longitudinal and transverse wall by having an inclined surface which forms a ramp, said inclined surface having an angle of inclination with respect to the longitudinal wall and on which the travel reduction element is located. The ramp keeps the heating element in the housing by compensating for the clearance between the heating element and the housing regardless of the size of the game, without requiring excessive insertion efforts. To compensate for the clearance, it is meant that the displacement reduction element is configured to come into contact with the heating element.

- The ramp shape of the deflection reducing element allows to gradually push, during its insertion, the heating element in the direction of the opposite longitudinal and transverse wall. This form of ramp extends from the upstream end of the displacement reduction element, that is to say the end to be first covered by the heating element during its insertion, which is located in the plane of the longitudinal and transverse wall. The downstream end may correspond to the top of the displacement reduction element, that is to say the innermost point of the housing. It is understood that this form of ramp, associated with the reduced width characteristic, ensures a deflection of the heating element during insertion and deformation of the displacement reduction element rather than the heating element when the deflected heating element meets the opposite longitudinal and transverse wall.

- The inclined surface may have bearings parallel to the longitudinal and transverse wall on which the displacement reduction element is located. In this way, the deflection of the heating element is progressively made towards the opposite longitudinal and transverse wall.

- It can be provided that the downstream face of the deflection reducing element, that is to say a face connecting the top of this element to the longitudinal and transverse wall, towards the bottom wall, is substantially perpendicular to the longitudinal and transverse wall and parallel to the bottom wall. - The displacement reduction elements are arranged alternately on a first longitudinal and transverse wall and on a second longitudinal and transverse wall. "Alternately" means for example that the displacement reduction elements of the first longitudinal and transverse wall do not share the transverse axes of the deflection reduction elements located on the second longitudinal and transverse wall. The offset can be constant. It is understood that this characteristic is also applicable in the case where there is only one element of reduction of deflection on each of the longitudinal and transverse walls.

- The deflection reducing element has at least one protruding edge arranged in the extension of the inclined surface and which forms the top of the deflection reducing element, this apex edge being the part of the reduction element of the deflection element. the most inside travel of the dwelling. In this way, this edge is a part of the displacement reduction element may always be in contact with the heating element during the insertion thereof, regardless of the games of manufacture of the frame and of the heating element.

According to another series of features of the invention, it can be provided that:

- The deflection reducing element comprises a contact face facing inwardly of the housing, said contact face being configured to include at least one recess.

- The recess is centered on the deflection reducing element, according to the longitudinal direction of insertion of the heating elements in the housing.

- The recess is a punctual recess.

- The recess is linear and has an axis of elongation substantially perpendicular to the axis of elongation of the longitudinal and transverse walls.

- The displacement reduction element comprises a single recess.

- The contact surface of the displacement reduction element, intended to come into contact with the heating element, is a rounded face, the recess being made at the top of this rounded face.

- The deflection reduction element comprises a plurality of recesses, forming a plurality of protuberances between which respectively extend each of the recesses.

Furthermore, the frame may comprise at least one holding member in position the heating element in the housing. It should be understood here that the holding member is an independent element, reported in the frame according to the invention. It is therefore distinct from the longitudinal and transverse walls and the aforementioned insertion path. More specifically, the invention provides that the holding member comprises at least one pin configured to be inserted into a receiving orifice arranged in one of the aforementioned longitudinal and transverse walls. The pin is advantageously defined to extend at least partially inside the insertion path, and to be constrained by the heating element during its passage, and to exert a stress on this heating element once it placed in its housing, constraint to maintain said heating element in place in said housing.

- Advantageously, the pin comprises a head intended to extend projecting inside the housing in which the heating element is received and a foot intended to be inserted into the receiving orifice arranged in the longitudinal wall defined above. More specifically, the head of the pin has a substantially flat face advantageously placed against the inner face of the longitudinal and transverse wall in which the receiving orifice is arranged once the pin installed in the latter, and it extends, within of the housing in which the heating element is received, in the direction of the other longitudinal and transverse wall which defines this housing.

The invention also relates to an electric heating device comprising at least one frame as described above and wherein the at least one heating element is disposed.

Said at least one heating element can be deflected in the vicinity of the displacement reduction element, in the direction of the wall opposite to the longitudinal wall on which the displacement reduction element 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 an overall perspective view of an electric heating device according to the invention, comprising a frame in which heating elements have been inserted and at one end of which is fixed an electrical connection interface;

FIGS. 2 to 4 show a first embodiment of the invention and its variants, in particular with a figure 2 consisting of an enlargement of part of the frame of an electric heating device according to the invention showing two elements of reduction of deflection equipping respectively a longitudinal and transverse wall participating in forming the frame; and FIGS. 5 to 7 show a second embodiment of the invention and its variants, wherein at least one deflection reducing element comprises a recess in a contact face facing the interior of the housing.

It should first be noted that the figures show the invention in detail and 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 of 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 defined by the trihedron L, V, T shown in the figures. The longitudinal axis L corresponds to the elongation direction of the frame of the electric heating device, the transverse axis T perpendicular to the longitudinal axis L, corresponds to the direction followed by the flow of air to be heated through the device. heating and the vertical axis V is perpendicular to both the longitudinal axis L and the transverse axis T. It should be noted that the choice of designations of these axes is not limiting the orientation that can take the electric heater in its application to a motor vehicle.

The electric heating device 1 shown in FIG. 1 is intended to be 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. in thermal energy restored 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 electric heating device 1.

FIG. 1 shows an electric heating device 1 according to the invention, comprising a frame 3 in which heating elements 5, capable of transforming an electric current into thermal energy, have been inserted. To compensate for the manufacturing gaps between the heating elements 5 and the frame 3, the frame 3 comprises displacement reduction elements 10 which will be described later.

The heating elements 5 comprise means capable of exchanging heat, such as radiant elements 53 making it possible to increase the heat exchange surface, with the flow of air passing through the electric heating device 1. The heating elements 5 comprise also electrodes 54 between which are arranged resistive heating elements, for example positive temperature coefficient resistors (PTC), and against which are fixed the radiant elements 53 · The electrodes 54 and the PTC resistors make it possible to transform an electric current into thermal energy. It should be noted that the resistors with a positive temperature coefficient can be glued directly on the radiant elements 53 · The frame 3 comprises a heating compartment 30, forming a receiving housing for the heating elements 5, and a connection interface 100 formed at one of its ends. The heating elements 5 are inserted in housings 7 formed inside the heating compartment 30. The connection interface 100 closes an opening 50 through which the heating elements 5 are inserted in the housings 7 of the heating compartment 30, at the same time as it allows the connection of the electric heating device 1 to an electrical network of the vehicle allowing the electrical supply of the heating elements 5

The frame 3 and the heating compartment 30 have a rectangular parallelepiped shape. The two main faces of the frame 3, respectively front and rear, opposite along the transverse axis T, are perforated to allow the passage of an air flow and a diffusion of heat in the duct where the electric heater 1 is installed. The frame 3 comprises a median plane corresponding to a plane passing through one half of the frame and being perpendicular to a direction followed by the flow of air flowing through the electric heating device 1. It is understood that the front and rear faces of the frame 3 extend in planes parallel to the median plane.

It is also noted that the frame 3 comprises strips 9 disposed here at the periphery of the heating compartment 30. These strips 9 participate in the stiffening of the frame 3 and include ventilation slots 90 allowing the flow of air to flow to through. The ventilation slots 90 are positioned one after the other along the longitudinal axis L of the heating device 1, it being understood that the shape and the number of the air passages here formed by the slots is not limiting. of the invention. It follows from the arrangement at the periphery of the bars 9 that the housing 7 are contiguous to each other.

The heating compartment 30 comprises a plurality of walls. Among these walls, there are longitudinal and transverse walls 23, 25 extending mainly along the longitudinal axis L. In what follows, it may be necessary to use the term of longitudinal wall to describe the longitudinal and transverse walls. These comprise in particular two lateral longitudinal walls 23 and at least one intermediate longitudinal wall 25. The lateral longitudinal walls 23 delimit between them a vertical dimension of the heating compartment 30, and the intermediate longitudinal walls 25 extend parallel to the lateral longitudinal walls. 23 and inside the heating compartment 30, so as to define, between them and with the longitudinal side walls 23, several housings 7 inside the heating compartment 30. Thus, each housing 7 of the frame 3 is delimited by walls. More specifically, each housing 7 is delimited vertically by two longitudinal walls 23, 25, which may be lateral 23 or intermediate 25. According to the illustrated embodiment, the frame 3 comprises two housings 7 with an intermediate longitudinal wall 25.

For each housing 7, a longitudinal longitudinal wall 23 and the intermediate longitudinal wall 25 delimit, between them and vertically, an insertion path for the heating element 5 · The insertion path corresponds to the path taken by the heating element 5 when inserted inside the frame. The spacing between the longitudinal walls 23, 25 of the same housing 7 corresponds to the vertical dimension of the heating element 5, to the manufacturing sets.

It is understood that the transverse dimension of the walls defines the transverse dimension of the housings, and therefore the transverse dimension of the heating elements that can be accommodated in the heating compartment. According to one characteristic of the invention, the width, that is to say the transverse dimension, of the longitudinal and transverse walls is between 8 and 18 millimeters.

Each housing 7 is delimited by a bottom wall 21 extending in a vertical transverse plane. This bottom wall 21 is situated opposite the opening through which the heating elements 5 are inserted in the heating compartment 30. It should be noted that, according to the embodiment shown, the heating elements 5 are inserted. in the housings 7 in a direction of insertion parallel to the longitudinal axis L. The insertion direction S is defined from the opening towards the bottom wall 21.

The frame 3 also comprises ribs 6 transversely delimiting the insertion path of the heating element 5 in the housing. For this, the ribs 6 extend at least between two longitudinal walls 23, 25 forming a same housing 7, and it should be noted that these ribs also have a role of stiffening the frame 3 and the heating compartment 30.

According to the invention and in order to compensate for the manufacturing clearance between a heating element 5 and the walls delimiting the housing 7 receiving this heating element, the frame 3, and more particularly at least one longitudinal and transverse wall 23, 25 participating in defining a housing receiving a heating element, comprises at least one displacement reduction element 10 mentioned above.

According to various practical cases, each of the longitudinal and transverse walls defining a housing comprise at least one deflection reducing element, so that these displacement reduction elements are distributed, for example regularly, between the longitudinal and transverse walls, and / or a longitudinal and transverse wall may comprise a plurality of displacement reduction elements, so that the heating element can interact with displacement reduction elements in several parts of the frame, its position in the housing being all the more stable. In the latter case, it is understood that several deflection reducing elements can be aligned along the longitudinal and / or transverse direction of the wall which carries them.

It is interesting that in the month a displacement reduction element is in an area defined between the bottom wall and a central portion of the housing relative to its longitudinal dimension, and for example in a zone arranged between 10 and 30 millimeters of the wall bottom, in particular to reduce the travel end of insertion stroke of the heating element, that is to say in the area where the heating element is most likely to debate.

FIG. 2 illustrates the frame without the heating elements, to make visible two displacement reduction elements 10 respectively arranged in a housing 7, across the insertion path of the heating element brought to occupy this housing, each reduction element. deflection being configured to have a width, i.e. a transverse dimension, determined to oppose a defined resistance to the insertion of the heating element.

A plurality of shapes that can take a displacement reduction element, will be described later as soon as it has a width corresponding to a determined ratio of the width value of the longitudinal and vertical wall that carries it.

More particularly, in the case described above of a longitudinal and vertical wall whose width is between 8 and 18 millimeters, the deflection reduction element may have a width of the order of 1 to 2.5 millimeters.

These values given by way of example make it possible to define a ratio between the width of the deflection reduction element and that of the longitudinal and vertical wall which carries it, and thus substantially of the heating element inserted in the defined housing. part by this wall. According to the invention, it has been defined that a ratio allowing deformation along an axis of the deflection reduction element under the insertion force of the heating element, when it is resting on the wall longitudinal and transverse transverse against which it is deflected, is of the order of 5 to 30%. It is understood that the figures are schematic here and are intended to represent the smaller width of the deflection reduction elements relative to that of the longitudinal and vertical walls, without they being limiting to a precise value of a ratio between the widths such as than previously mentioned. It follows from this feature that the deflection reducing element 10 has a width less than that of the wall. Advantageously, the deflection reduction element is arranged transversely so as to be centered substantially on the median longitudinal axis of the longitudinal and transverse wall 23, 25 which carries it. The heating element is deflected by the deflection reducing element in a balanced manner, on either side of this longitudinal median longitudinal and transverse wall, which corresponds to the median longitudinal axis of the heating element when this one is in place in the housing.

According to the invention, the function of reduction of travel is ensured without destruction of the heating elements since it is the displacement reduction element which deforms, if the efforts at the insertion are too important, because of the small amount of material that it represents. And it should be noted that the deformation, and therefore the sagging, of the displacement reduction element does not penalize the function that it must fulfill since it is in contact with the heating element, when the game has been filled since the heating element bears against the opposite longitudinal and transverse wall, that the displacement reduction element is deformed. It is understood that if the game was not to be filled completely, the force applied by the heating element on the deflection reducing element would be too small to deform the latter, which would retain its original shape and its role of reducing at most the deflection.

Furthermore, in terms of dimensioning, the deflection reducing element 10 may have a length, measured along the longitudinal axis L, which may for example be between 10 and 15 mm.

Furthermore, the height of a displacement reduction element, the height being measured along the vertical axis V, may be of the order of 1 to 10% of the height of the housing in which it extends. Preferably, the height of the deflection reducing element, measured along the vertical axis V, is between 0.5 and 1.5 millimeters, knowing that the production clearance between the heating element 5 and the housing 7 is generally between 0.2 millimeters and 1 millimeter.

It should be noted that in the case of a plurality of displacement reduction elements on longitudinal and transverse walls defining the same housing, the sum of the heights of each of the displacement reduction elements is taken into consideration, and especially when these elements are arranged in the same area of the housing, to ensure that the presence of the displacement reduction elements does not generate a bottleneck that would increase the insertion forces of the heating elements.

As the displacement of the heating elements 5 inside the housings may be greater at their longitudinal ends close to the bottom wall, it is preferable that the deflection reducing elements are located in the vicinity of the bottom wall, and in particular in an area defined between the bottom wall 21 and a central portion of the housing 7 relative to its longitudinal dimension.

In each of the embodiments and embodiments presented in the following, the displacement reduction element 10 may be formed by an insert, that is to say a part made separately and then secured to the corresponding longitudinal wall. or it may be integral with the longitudinal and transverse wall 23, 25 of the housing 7 · in particular by a single molding operation.

Of course, a mixture of the different forms and / or different arrangements of displacement reduction elements for the same frame 3, or even the same longitudinal and transverse wall, is possible.

According to a first embodiment, illustrated in particular in FIG. 2, each displacement reduction element 10 projects from a longitudinal wall 23, 25 and has an inclined ramp surface 11 which progressively extends towards interior of the housing 7, approaching the opposite longitudinal wall. More particularly, the deflection reducing element 10 has, in longitudinal section, that is to say in a longitudinal and vertical section plane, a triangular shape.

The inclined surface 11 extends from an upstream end 12 of the displacement reduction element, away from the corresponding longitudinal wall, and towards the opposite longitudinal wall. Specifically, the inclined surface 11 forms an angle G with the longitudinal wall 23, 25 from which the deflection reducing member is protruding.

The ramp formed by this inclined surface extends in the extension of the longitudinal wall and extends to an end edge forming a vertex edge 13, this end edge being the part of the reduction element displacement most inside the housing and therefore the portion likely to be in contact with the heating element regardless of manufacturing games.

According to one characteristic of this embodiment, the deflection reducing element may comprise a downstream end which extends away from the bottom wall 21. In this way, a clearance is formed between the displacement reduction element. and the bottom wall for facilitating the deformation of the deflection reducing element by the effect of the insertion of the heating element. In the example illustrated in FIG. 2, the ramp extends smoothly and continuously from the upstream end 12 to the apex edge 13, so that the insertion force of the heating element remains measured, smoothly that could form an element without ramp. Depending on the dimensions of the heating element, that is to say according to the production sets of this heating element and the frame, it is understood that the inclined surface will form an obstacle to the insertion of the heating element at the level of the heating element. its upstream end or at the edge of the summit. In any case, the presence of this deflection reducing element tends to deflect the heating element towards the opposite longitudinal wall, and to position the heating element in position in the frame, so as to reduce the flapping of the components when the heater is assembled. As has been previously stated, this is achieved with a small width displacement reduction element, that is to say having the dimensions as mentioned above, so that this displacement reduction element can be deformed. when the game is perfectly filled, under the effect of the thrust of the heating element also in contact against the opposite longitudinal and transverse wall.

The deflection reduction element further comprises a downstream face 14, which connects the apex edge 13 to the longitudinal wall, downstream of the apex edge, that is to say the opposite of the inclined surface 11 forming a ramp. In the example illustrated in FIG. 2, this downstream face 14 is straight, arranged in a vertical and transverse plane also comprising the vertex edge. In this way, the downstream face is perpendicular to the longitudinal wall and parallel to the bottom wall. It is understood that in a variant not shown, the downstream face could be inclined and have a vertical dimension gradually decreasing to the junction of the downstream end 15 with the longitudinal wall, since this junction with the longitudinal wall extends away from the bottom wall according to the feature of the invention described above.

The displacement reduction element has effect in a zone of the frame particularly sensitive to these deflections, but without the disadvantage of being integral with the bottom wall, which forms a surface for stopping the translation of the heating element. , perpendicular to its insertion into the housing, and the rigidity that would result.

The fact that the junction of the downstream end 15 of the deflection reducing element with one of the walls defining the housing is independent of the bottom wall allows a flexibility of the deflection reducing element in its zone of contact with the heating element and in particular at the vertex edge 13, and it is understood that this flexibility combined with the reduced width of the displacement reduction element allows this element to sag slightly under the effort insertion in the direction of the bottom wall 21 so as to slightly reduce this insertion force to provide. Advantageously, the deflection reduction element is in an area close to the bottom wall, and in any case in the second longitudinal portion of the frame, that is to say, relative to this longitudinal dimension, between a central portion housing and the bottom wall. It may be provided that the downstream end of the displacement reduction element, namely the downstream face 14 or the junction of this downstream face with the longitudinal wall in the case where the downstream face is not parallel to the wall of bottom 21, is arranged at a longitudinal distance from the bottom wall of between 10 and 30 millimeters. In this way, the downstream end is sufficiently far from the bottom wall to provide, if necessary, a certain flexibility to the deflection reducing element, in particular at its vertex edge 13, while remaining in a context of reduction of travel at the end of the insertion stroke of the heating element, that is to say in the zone where the heating element is most likely to debate.

According to a first variant embodiment of this first embodiment, illustrated in FIG. 3, the displacement reduction element differs from the above in that the inclined surface 11 forming the guide ramp for the heating element has bearings. 16, here three in number. These bearings regularly interrupt the slope of the ramp and they thus provide interruptions in the increase of the insertion force of the heating elements in the housing. It will be understood that the number of steps could be different from that illustrated here, without departing from the context of this embodiment of the invention.

FIG. 4 illustrates a second variant of this first embodiment of the invention, which is distinguished in particular by the configuration of the upstream face forming a ramp.

This inclined surface 11 here has a triangular shape having the effect of forming a projecting edge 17 oriented towards the housing 7 · The projecting edge 17 is intended to come into contact with the heating element 5 · The projecting edge 17 extends preferably in the direction of insertion S of the heating element in the housing. Thus, here the projecting edge 17 extends along the axis of longitudinal elongation of the longitudinal wall 23, 25 on which is located the displacement reduction element 10.

As before, the deflection reducing element has an inclined surface 11 forming an angle G with the longitudinal wall 23, 25 on which it is located, and this deflection reducing element is configured to extend away from the bottom wall, with a downstream end engaging the longitudinal wall.

A second embodiment will now be described, with reference to FIGS. 5 to 7, which differs from the foregoing in that the displacement reduction element (s) comprises (s) a recess 72. Each displacement reduction element 10 has a free end face forming contact face 70 for the heating elements 5 inserted in the housing equipped with such a displacement reduction element. This contact face 70 is the face facing the interior of the housing 7, opposite the corresponding longitudinal and transverse wall. The contact face 70 has here a rounded shape, namely a curved and without edges. The displacement reduction element 10 takes for example the shape of a boss.

The contact face 70 is configured to include at least one recess 72. The recess 72 is advantageously disposed at the top 71 of the deflection reducing element, that is to say at the top of the form. bulging of the contact face 70.

In the embodiment illustrated in FIG. 5, the displacement reduction element 10 consists of a boss having the regular shape of a dome, and a single recess 72 is formed on this displacement reduction element, in this case arranged substantially in the center of the contact face 70.

The recess 72 is thus centered on the displacement reduction element 10, here longitudinally, that is to say in the longitudinal direction L of insertion of the heating elements in the housing, and transversely, that is to say in the transverse direction T of elongation of the corresponding longitudinal and transverse wall perpendicular to said longitudinal direction.

The recess 72 is in this embodiment a punctual recess, made by punching the contact face. The shape of the recess corresponds in this way to the male shape of the punch, and the recess here has a straight cylindrical bore, of vertical axis, perpendicular to the longitudinal wall forming a support of the displacement reduction element 10.

The recess 72 is delimited by a wall whose free end, at the contact face, forms a projecting edge edge. In this case of a punctual recess, the protruding edge edge has a circular shape surrounding the recess. It may be noted that during its insertion into the housing, the heating element is successively encountered with a first projecting edge portion 74, upstream of the recess, and then a second projecting edge portion 76, downstream of the recess. this recess. During the insertion, the thrust force exerted on the heating element, being understood that it is deflected by the presence of the displacement reduction element in the housing, can generate a local deformation of the first portion of the protruding edge, which tends to fade in the free space formed by the recess 72. In this way, the stresses to the heating element in the narrowest zone of the housing, that is to say in the area where the displacement reduction element is the most across the insertion path, can be decreased, especially as the displacement reduction element meets the characteristic that its width is of the order of 5 to 20% of that the wall that carries it, and therefore approximately that of the heating element.

The depth of the recess 72 is obtained by the vertical depression more or less long punch in the thickness of the displacement reduction element, it being understood that this recess can extend over a height substantially equal to 10% the height of the deflection reducing element, sufficient to generate the local deformability of the projecting edge bordering the recess, and that it can extend over the entire height of the deflection reducing element, for in addition to this local deformability, bring a significant effect of reducing the frame weight.

In a variant not shown, the recess is linear, so as to extend significantly over the transverse dimension of the displacement reduction element. The recess 72 has an axis of elongation substantially perpendicular to the axis of elongation of the longitudinal walls, and it thus has a slot shape that extends perpendicularly to the direction of insertion of the heating elements in the dwellings. . The recess can thus extend over the entire width of the displacement reduction element, it being understood that according to the invention, this width is small, in a proportion of 5 to 20%, with respect to the width of the longitudinal and transverse wall. In this way, a flexibility of the displacement-reducing element is generated at an edge edge delimiting the recess, which is homogeneous over the entire width, or transverse dimension, of the reduction element of the deflection element. travel.

FIG. 6 represents a first variant of this second embodiment of the invention, in which the shape of the recess 72 is different, presenting here a triangular section instead of the rectangular section previously described. In other words, the point recess may be in the form of a point. In accordance with what has been described, the point recess has the corresponding shape of the punch used to make this recess.

This results in a tapered shape of the protruding edges 74, 76 delimiting the recess upstream and downstream, and therefore a greater faculty of local deformation under the effect of the passage of the heating element.

FIG. 7 represents a second variant of the second embodiment of the invention, in which the displacement reduction element this time comprises a plurality of recesses, forming a plurality of protuberances 78 between which each of the recesses respectively extends respectively. . Several of these protuberances can be configured to fit into a rounded envelope consisting of said contact face, here shown in dotted lines. Each recess 72 is delimited upstream and downstream by projecting ridges 74, 76, and each edge protruding upstream 74 forming a protrusion inscribed in the envelope acting as a contact face is likely to locally deform and collapse to the passage of the heating element

5.

We will now describe the mounting of the electric heater 1 comprising the frame 3 according to the invention.

At first, the heating elements 5 are inserted in the appropriate housings 7 inside the heating compartment 30. For this, the heating elements 5 are inserted through the opening formed at one end of the frame 3, and the heating elements 5 are slid in translation towards the bottom wall 21 of the housing 7, in particular along the insertion direction indicated by the arrow S.

During insertion into a housing equipped with at least one deflection reducing element, the heating element 5 comes into contact with the deflection reducing element arranged across the insertion path. This heating element 5 is then deviated from its initial rectilinear trajectory, being guided in the direction of the longitudinal wall opposite to that on which is formed the displacement reduction element. The fact that the deflection reducing element has a free downstream end, that is to say an end extending longitudinally away from the bottom wall, generates a flexibility that allows a slight deformation of the element. reduction of travel at the edge in contact with the heating element. In this way, the forces required to push the heating element to the bottom wall, while it is also pushed against a longitudinal wall through the displacement reduction element, are minimal.

The insertion of the heating element 5 continues until it meets the bottom wall 21 or another mechanical stop of the heating device.

Finally, the heating compartment 30 is closed by the connection interface 100. The connection interface 100 is then disposed at one end of the heating compartment 30 and allows the connection of the electric heating device 1 to an electrical network of the vehicle. . The heating device 1 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 which it has set itself and in particular to propose a heating device 1 in which the heating elements 5 are easily inserted and do not debate inside the device. their accommodation, by means of particular deflection reducing elements in that they have a width defined with respect to the width of the longitudinal and transverse walls which carry them, and therefore according to the width of the heating elements brought to penetrate the housing defined by these longitudinal and transverse walls. The width thus defined is such that it represents a percentage of the order of 5 to 30% of the width of the wall and therefore approximately of the heating element, which implies in the event of significant effort exerted by the element heating element on the displacement reduction element, and in particular when the heating element is blocked on the opposite side by the other longitudinal and transverse wall participating to define the ramp-shaped housing and therefore when the displacement of the heating element is completely reduced, deformation under the force of the displacement reduction element rather than the heating element. Thus we do not penalize the heat exchange performance.

It should be noted that the displacement reduction element according to the invention is not a deformable element brought to return to its original position by return force, but a fixed element whose position within the housing n ' is not modified by the passage of the heating element, and optionally with a locally generated flexibility at the edge edge formed at the end of ramp to allow the passage of this heating element.

The invention as just described can not be limited to the means and configurations exclusively described and illustrated, and also applies to any means or configurations, equivalents and any combination of such means or configurations. Similarly, if the invention has been described here according to alternative embodiments each implementing separately a type of arrangement of the displacement reduction elements, it goes without saying that the different arrangements presented can be combined without this adversely affecting the invention.

Claims

1. Frame (3) of an electric heating device (1) of a flow of air circulating inside a ventilation, heating and / or air-conditioning system of a motor vehicle, said frame (3) comprising at least one housing (7) for receiving at least one heating element (5), the housing (7) being delimited by a plurality of longitudinal and transverse walls (23, 25) forming an insertion path longitudinal arrangement for a heating element, characterized in that at least one of the longitudinal and transverse walls (23, 25) of the housing (7) comprises a deflection reducing element (ΐq) projecting from said wall and having a dimension transverse of the order of 1 to 2.5 millimeters.

2. Frame according to the preceding claim, characterized in that the deflection reduction element (ΐq) has a transverse dimension of the order of 5 to 30% of the transverse dimension of the longitudinal and transverse wall which carries it.

3. Frame according to claim 1 or 2, characterized in that the transverse dimension of the wall which carries said deflection reduction element is of the order of 8 to 18 millimeters.

4. Frame according to one of the preceding claims, characterized in that the deflection reducing element (ΐq) is arranged transversely so as to be centered substantially on the median longitudinal axis of the wall (23, 25) which the door.

5. Frame according to any one of the preceding claims, characterized in that the longitudinal and transverse walls (23, 25) defining the housing (7) each comprise at least one displacement reduction element (10).

6. Frame according to any one of the preceding claims, characterized in that at least one longitudinal and transverse wall (23, 25) comprises several displacement reduction elements (10).

7. Frame according to the preceding claim, characterized in that several deflection reducing elements (ΐq) are aligned along the longitudinal direction and / or transverse of the wall (23, 25) which carries them.

8. Frame according to any one of the preceding claims and wherein the insertion path is delimited longitudinally by a bottom wall (21) which extends opposite an opening through which can be inserted the heating element intended to come into the housing, a direction of insertion being defined since the opening to the bottom wall, characterized in that the deflection reducing element (ΐq) is in an area defined between the bottom wall (21) and a central portion of the housing (7) relative to its longitudinal dimension.

9. Frame according to any one of the preceding claims, characterized in that the displacement reduction element (ΐq) is integral with the longitudinal and transverse wall (23, 25) on which this displacement reduction element ( ΐq) is located.

Electrical heating device (1) comprising at least one heating element (5), characterized in that it comprises a frame (3) according to any one of the preceding claims wherein the at least one heating element (5) is willing.