FR3078147A1 - FRAME FOR AN ELECTRIC HEATING DEVICE COMPRISING AT LEAST ONE DEVICE FOR MAINTAINING HEATING ELEMENTS - Google Patents

Abstract

A frame (3) of an electric heating device (1) for a flow of air circulating inside a ventilation, heating and / or air-conditioning system of a motor vehicle comprises at least one heating compartment (30) having at least one housing (7) for receiving a heating element (5), the housing (7) being defined at least by two longitudinal walls (23, 25) vertically defining an insertion path for the heating element (5), each longitudinal wall (23, 25) comprising an inner face (230, 250) oriented towards the insertion path, The frame (3) comprises at least one holding member in position of the heating element (5) in the housing (7), the holding member comprising at least one pin (4) configured to be inserted into a receiving orifice (231) arranged in one of the longitudinal walls (23, 25) .

Description

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

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

When the engine is started and for a certain period of time following the starting time, the calories transported by the engine coolant are insufficient to ensure rapid and efficient heating of the air brought into the passenger compartment. This is observed more particularly with certain types of engine and has a drawback in cold weather, since not only the internal temperature of the passenger compartment cannot be raised quickly, but also the functions of demisting and defrosting cannot be effectively performed. .

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

Such an additional electric heating device generally comprises a frame inside which are arranged a plurality of heating elements each arranged in a housing defined by walls of the frame. Each heating element, or heating rod, comprises parallel conductive plates between which are mounted resistive heating elements, for example resistors with positive temperature coefficient (PTC), and radiant elements attached to these conductive plates and increasing the surface area of heat exchange with the air flow passing through the electric heater. Each heating element is inserted into its own housing, then connected to an electrical connection element for supplying the resistive heating elements.

The manufacturing clearances, on the one hand, of the housings formed in the frame and, on the other hand, of the heating elements, generate a mounting clearance of each heating element which can be placed at a distance from the longitudinal walls delimiting the housing which l 'accommodates, so that these heating elements can debate and generate noise when the vehicle is running.

To avoid the deflection of the heating elements, an electric heating device frame can be equipped with elastic means for holding in position, which consist of tongues, the free end of which is arranged across the housing and the path for inserting the elements. heating, this free end tending to retract during the passage of the heating element, then to push this heating element against one of the walls of the housing to keep it in position by elastic return effect. These tabs are made integral with a wall defining the housing at one of their ends, they are free at the opposite end, and they have, in their original position, an arrangement such that the free end is released from the wall defining the housing. 11 results in a brittleness which can result in the breakage of this elastic tongue and in the loss of the function of holding in position of the heating elements.

An alternative is known in which the frame comprises means for plastic deformation of the heating elements, arranged projecting from the walls participating in delimiting the housing in which the heating element is inserted. These plastic deformation means make it possible to constrain and plastically deform each heating element in the direction of the opposite wall of the housing, in particular during the insertion of the heating element into the housing. These plastic deformation means allow the heating elements to be pressed into the housing, while eliminating the presence of elastic elements exerting restoring forces on the heating elements, elastic elements which are liable to break. However, the insertion of the heating elements into the heating body being done by a robot, the meeting of the heating elements with the plastic deformation means has the consequence of considerably increasing the insertion forces. The sensors fitted to the robot repeatedly detect that the increase in insertion forces corresponds to the heating elements being brought into abutment in the heating body. For security reasons, this abutment detection forces the robot to stop, so that an operator can verify it. Stopping the robot and checking by the operator interrupts the production chain, which generates a waste of time and an additional manufacturing cost.

In this context, the invention aims to propose an alternative to existing solutions, an alternative which allows simple, effective, reliable and inexpensive maintenance of the heating elements in the context of the electric heating device.

To this end, the invention provides a frame for an electric heating device for an air flow circulating inside a ventilation, heating and / or air conditioning installation of a motor vehicle, said frame comprising at least one heating compartment having at least one housing intended to receive a heating element, the housing being defined at least by two longitudinal walls vertically delimiting an insertion path for the heating element, each longitudinal wall comprising an oriented internal face towards the insertion path. According to the invention, the frame comprises at least one member for holding the heating element in position in the housing.

it should be understood here that the holding member is an independent element, attached in the frame according to the invention. 11 is therefore distinct from the above-mentioned longitudinal walls and insertion path. More specifically, the invention provides that the holding member comprises at least one pin configured to be inserted in a receiving orifice arranged in one of the above-mentioned longitudinal 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 aimed at holding said heating element in place in said housing.

Advantageously, the pin comprises a head intended to project into the interior of 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 previously defined. More specifically, the head of the pin has a substantially flat face, arbitrarily designated in the following as a lower face, advantageously placed against the internal face of the longitudinal wall in which the receiving orifice is arranged once the pin is installed in the latter. , and it extends, within the housing in which the heating element is received, in the direction of the other longitudinal wall which defines this housing. This direction, substantially perpendicular to the main direction of elongation of the longitudinal walls, or longitudinal direction will, in what follows, be designated as vertical direction.

Advantageously, the pin is made of a material chosen for its elastic properties, in such a way that, under the effect of the force exerted by the heating element during its insertion, along the insertion path, in its housing , the head of the pin deforms elastically, thus allowing the passage of said heating element without tearing the pin out of the aforementioned receiving orifice. By way of nonlimiting example, the pin can be produced by injecting, in a mold, a material of the elastomer type. Once the heating element is in place within its housing, the head of the pin, elastically deformed, then exerts, by an elastic return effect in its original position, an essentially vertical compressive stress on said element heating, keeping it that way, especially in the vertical direction, within its housing.

According to one or more characteristics which can be taken alone or in combination, provision may be made for:

- The receiving orifice of the pin passes right through the longitudinal wall in which it is arranged, that is to say that it extends from one face to the other of this wall in the vertical direction previously defined. In other words, the foot of the pin extends over the entire thickness of the longitudinal wall in which the abovementioned receiving orifice is arranged, and it opens, on the one hand, at the level of the internal face , previously defined, of this wall and, on the other hand, at the level of the external face, opposite to the internal face and parallel to the latter, of this same wall.

- The shapes and dimensions of the pawn's foot are defined complementary to those of the aforementioned receiving orifice. More precisely, the shapes and dimensions of the pin foot are defined, taking into account the manufacturing tolerances of said pin and the manufacturing tolerances of the reception hole defined above, so that the pin foot can be easily inserted into the receiving port, but without excessive play. In particular, the respective shapes and dimensions of the pin foot and the receiving orifice are defined in such a way that the extraction of the pin from this orifice can only result from a voluntary maneuver and an effort of a operator.

- The foot of the pin has at least one axis of symmetry coincident, when the pin is inserted into the reception hole defined above, with a vertical axis of symmetry of said reception hole. Advantageously, the dimension, in the direction of this vertical axis of symmetry, of the foot of the pin, is substantially equal to that of the receiving orifice. In other words, when the piece is inserted into its receiving hole, the foot of the piece is flush with the hole through which the receiving hole opens into the internal face of the corresponding longitudinal wall, and it is also flush with the hole through which this receiving orifice opens into the external face of said wall.

- The vertical axis of symmetry of the pawn's foot is also the axis of symmetry of the pawn's head.

- The length of the head of the pin, defined as the dimension of this head in the longitudinal direction previously defined, is greater than the longitudinal dimension of the receiving orifice. More specifically, the edges of the head of the pin project beyond the edges delimiting the hole through which the receiving orifice opens into the internal face of the longitudinal wall in which it is arranged. In other words, the surface of the underside of the head of the pawn is greater than the surface of this hole.

- The thickness of the head of the pin, that is to say its dimension in the previously defined vertical direction, is maximum at the right of the receiving orifice and it decreases towards the periphery of said head. According to a particularly advantageous, but not exclusive, embodiment of the invention, the head of the pin has substantially the profile of a portion of a sphere. Alternatively, it has a substantially frustoconical profile, the largest diameter of which is formed by the edges of the underside of this head. In other words, the head of the pin has, in particular in the longitudinal direction previously defined, a vertically inclined profile. It should be noted here that if a head having a shape of revolution has low manufacturing costs, such a shape is not exclusive and any other shape can be envisaged for the head of the pin forming the holding member.

- The pawn has a base which extends in the extension of the pawn foot, projecting from the foot opposite the head of the pawn in the vertical direction previously defined. In other words, the head of the pin projecting from the internal face of one of the longitudinal walls which delimits the housing in which the heating element is received, the base of the pin projects in projection from the external face of this longitudinal wall, the external face here being defined, as a reminder, like the face of this longitudinal wall parallel to the internal face and opposite to the latter.

- The vertical axis of symmetry, previously defined, of the foot of the pawn, is also vertical axis of symmetry for the base of the pawn.

- The edges of the base of the counter protrude from the walls which delimit the receiving orifice. It should be understood here that the base of the pin has a substantially planar face, designated in the following as an upper face, configured to be placed in contact with the external face of the longitudinal wall which delimits the housing in which the cbauffant element is received. when the pin is inserted into its receiving hole. In other words, the surface of the upper face of the base of the pin is greater than the surface of the hole through which the receiving orifice opens into the external face of the longitudinal wall in which said receiving orifice is arranged.

- The thickness of the base of the pin, that is to say its dimension in the previously defined vertical direction, is maximum with regard to the receiving orifice and decreases towards the periphery of said base. According to a particularly advantageous, but not exclusive, embodiment of the invention, the base of the pin forming the holding member has substantially the shape of a portion of a sphere. Alternatively, it has a frustoconical profile whose largest diameter is formed by the edges of the upper face of this base. In other words, the base of the pin has, in particular in the longitudinal direction previously defined, a vertically inclined profile. It should be noted here that if a base having a shape of revolution has low manufacturing costs, such a shape is not exclusive and any other shape can be envisaged for the base of the pin forming the holding member.

- The dimension, in particular longitudinal, of the base of the pawn is substantially less than the dimension, in particular longitudinal, of the head of this pawn. Advantageously, the same applies to the dimension of the base in the direction which defines, with the abovementioned longitudinal direction, the planes of the longitudinal walls which delimit the housing in which the heating element is received in the frame according to the invention. In other words, the surface of the upper face of the base of the pawn is less than the surface of the lower face of the head of the pawn.

- The foot of the pin has an opening configured to allow deformation, in particular longitudinal, of said foot when it is inserted into the receiving orifice arranged in the longitudinal wall of the frame according to the invention. Advantageously, the vertical axis of symmetry of the head, the base and the foot of the pawn, is also the vertical axis of symmetry for this opening. Advantageously, this opening crosses the entire base of the pin in the vertical direction previously defined, and it extends, in this same vertical direction, over all or part of the foot of the pin. In other words, this opening opens into an outlet at the vertical end of the base of the pin. This opening makes it possible to place the pin in the reception hole previously defined. Indeed, thanks to the elasticity of the material which constitutes the pin, the operator can exert, on the base of the pin, a pressure aimed at bringing the walls which delimit this opening towards the vertical axis of symmetry of the pin. It follows that the foot of the pawn and its base are deformed in such a way that the dimensions, perpendicular to the vertical direction, of the base of the pawn decrease. Thanks to its inclined profile, it is then possible to insert the base of this pin in the reception hole previously defined. Taking into account the respective dimensions of the foot and the base of the pawn, once the pawn is inserted into this orifice so that the underside of its head is in abutment against the internal face of the longitudinal wall in which is arranged l 'receiving orifice, the edges of the upper face of the base of the pin have crossed the edges of the hole through which the receiving orifice opens into the external face of the longitudinal wall. The walls of the pin foot and the base which delimit the aforementioned opening then return elastically to their initial position, and the pin is then blocked by a form of locking within the receiving orifice, the upper face of the base of the pin being placed against the external face of the longitudinal wall which delimits the housing in which the heating element is received. In other words, the longitudinal wall in which the orifice for receiving the aforementioned pawn is arranged is then sandwiched, or sandwiched between the head of this pawn and the base thereof, more precisely between the underside of the head of the pawn and the upper face of the base thereof.

- The pin extends over the entire transverse dimension of the longitudinal wall in which the receiving orifice is arranged. The width is here defined as being the dimension along the direction, here transverse, which, with the longitudinal direction, defines the longitudinal walls which delimit the housing in which the heating element is received. In the heating device in which the object of the invention frame is placed, it is also the direction followed by the flow which crosses the heating device in order to be heated there. According to this alternative embodiment, the head of the pin therefore substantially forms a bead which projects inwards towards the inside of the housing in which the heating element is received, substantially over the entire width of the longitudinal wall considered. Such a configuration allows, in particular, to distribute over the entire width of this longitudinal wall, the compressive stress that the pin and, more precisely, its head, exerts on the heating element once it is put in place in its housing the frame according to the invention. Another advantage of such a configuration is that, by increasing the surface of the underside of the head of the pin, it limits the risks of the latter being torn away from the receiving orifice during the insertion of the element. heating. However, it should be noted that, in such a configuration, the receiving orifice will advantageously not extend over the entire width of the longitudinal wall, in order to avoid weakening the latter by the arrangement of a slot over the whole of one of its dimensions.

- The same longitudinal wall comprises at least two receiving orifices arranged successively in the insertion path, each intended to receive a pin as previously described.

- At least one receiving orifice is provided in the vicinity of a bottom wall participating in delimiting each housing with the longitudinal walls.

- The frame comprises a plurality of receiving orifices and associated pins provided in the same housing, the pins having heights greater and greater according to the direction of insertion of the heating element in the housing.

The invention also relates to an electric heating device comprising at least one heating element and a frame defining at least one housing for receiving the heating element, characterized in that the frame is as defined above and in that the at least one heating element is held in position in the corresponding housing by a vertical compression stress generated by at least one pin inserted in a receiving orifice arranged in one of the longitudinal walls which delimit the housing in which the heating element is received.

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

- Figure 1 is a front view of an electric heating device according to a first embodiment of the invention, comprising a frame in which three heating elements have been inserted and at one end of which is fixed an electrical connection interface , the heating elements being separated from each other by an air passage zone formed by an openwork plate;

- Figure 2 is a perspective view of a detail of the frame of Figure 1, without one of the heating elements, so as to make visible different parts of this frame and the path of insertion of a heating element in within it,

- Figure 3 is a sectional view of a detail of the longitudinal wall of the frame illustrated in Figure 1, without a heating element so as to make visible a first variant of a member for holding the heating elements,

FIG. 4 is a schematic sectional view of the pin forming the holding member of FIG. 3,

- And Figure 5 is a schematic perspective view of one of the longitudinal walls of the frame illustrated in Figure 3> without heating element so as to make visible a second variant of the pin of a member for holding these heating elements.

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

In the description which follows, reference will be made to an orientation as a function of the longitudinal axes L, vertical V and transverse T, as defined by the trihedron L, V, T shown in the figures. The longitudinal axis L corresponds to the direction of elongation 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 passing through the device. heating, and the vertical axis V is perpendicular to both the longitudinal axis L and the transverse axis T. 11 It should be noted that the choice of names for these axes is not limiting of the orientation that can take the electric heating device in its application to a motor vehicle.

Referring to Figures 1 and 2, an electric heating device 1 according to the invention comprises a frame 3 in which heating elements 5> capable of transforming an electric current into thermal energy, can be inserted. To ensure the position of the heating elements 5 once they are inserted into their respective housings, the frame 3 includes various holding devices which will be described in detail below.

The electric heating device 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 into returned thermal energy 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 one of its walls for the insertion of the electric heating device.

Advantageously, 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 air flow passing through the electric heating device 1. The heating elements 5 also include electrodes 54 between which are arranged resistive heating elements, for example resistors with a positive temperature coefficient 55 (PTC), and against which the radiant elements are fixed 53 · The electrodes 54 and the PTC resistors 55 make it possible to transform an electric current in thermal energy to be transferred to the air flow passing through the electric heating device. It should be noted that the resistors with a positive temperature coefficient 55 can be bonded directly to the radiant elements 53 ·

The frame 3 comprises a heating compartment 30, forming a receiving casing for the heating elements 5, and a connection interface 100 formed at one of its ends. The heating elements 5 are inserted into housings 7 formed inside the heating compartment 30. It is understood that the connection interface 100 closes an access by which the heating elements 5 are inserted into the housings 7 of the heating compartment 30 at the same time as it allows the connection of the electrical 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 the general shape of a rectangular parallelepiped. The two main faces of the frame 3, respectively arbitrarily designated as front face 30a and rear face 30b (the rear face 30b is not visible in the figures), opposite along the transverse axis T, are perforated to allow the passage of the flow air to be heated and a diffusion of heat in the duct where the electric heating device 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 the transverse direction followed by the air flow circulating through the electric heating device 1. 11 it is understood that the front faces 30a and rear 30b of the frame 3 extend in planes parallel to the median plane. It is also understood that the terms front and rear are purely arbitrary and in no way prejudge the orientation of the frame 3 within the motor vehicle in which the heating device 1 is placed.

In the embodiment illustrated in Figures 1 and 2, it is also noted that the frame 3 comprises perforated plates 9 disposed between each housing 7 and extending in the median plane of the frame 3 · These perforated plates 9 participate in the stiffening of the frame 3 and form air passage zones. In the non-exclusive example, more particularly illustrated by FIGS. 1 and 2, the perforated plates 9 take the form of bars comprising ventilation slots 9θ authorizing the air flow to circulate through, the ventilation slots 9θ being positioned one after the other along the longitudinal axis L of the heating device 1. It will be understood that the perforated plates 9 can take the form of plates perforated with holes of circular section without departing from the context of the invention.

The housings 7 of the frame 3 are defined in particular by longitudinal walls 23, 25 extending along the longitudinal axis L. More precisely, each housing is defined by two longitudinal walls 23, 25, including a first longitudinal wall 23 and a second longitudinal wall 25 vertically defining an insertion path 26 for the heating element 5 · The insertion path 26 is the path taken by the heating element 5 when it is inserted into the housing 7 · In other words, the insertion path 26 corresponds to a volume occupied by the heating element 5 during its insertion. Thus, the spacing between the first longitudinal wall 23 and the second longitudinal wall 25 of the same housing 7 corresponds to the vertical dimension of the heating element 5> apart from the manufacturing clearance. According to the exemplary embodiment illustrated in FIGS. 1 and 2, the frame 3 comprises three housings 7 with a central housing and two lateral housings located on either side of the central housing.

Each longitudinal wall 23, 25 comprises an internal face 230a, 250a oriented towards the insertion path 26, as well as an external face, 230b, 250b, parallel to the corresponding internal face 230a, 250a and opposite to it according to the direction of the vertical axis V. The internal and external faces of the same wall are delimited by two end edges 23a, 23b, 25a, 25b extending longitudinally. For the first longitudinal wall 23, a first end edge 23a is defined which is opposite to a second end edge 23b (cf. FIG. 2). Likewise, for the second longitudinal wall 25, a first end edge 25a is defined which is opposite to a second end edge 25b, not visible in FIG. 2.

Each housing 7 is delimited, moreover, by a bottom wall 21. This bottom wall 21 is situated opposite an opening 5θ (cf. FIG. 1) through which the heating elements 5 enter the heating compartment 3θ> and which is intended to be covered by the connection interface 100. It should be noted that the heating elements 5 are inserted into the housings 7 in a direction of insertion parallel to the longitudinal axis L, the direction d insertion being defined from the opening 5θ towards the bottom wall 21.

Abutment elements 210 may extend from the bottom wall 21, in the direction of the opening 5θ · In other words, each abutment element 210 extends along the longitudinal axis L towards the interior of the housing 7 · Two abutment elements 210 can be provided per housing 7 · In general, the number of abutment elements 210 in a housing 7 is equal to the number of radiant elements 53 equipping the element heater 5 intended to enter this housing 7 ·

The frame 3 also includes ribs 6, 8 transversely delimiting the path of insertion of the heating element 5 · For this, the ribs extend in a plane defined by the vertical axis V and the longitudinal axis L, also called vertical longitudinal plane, perpendicular to the longitudinal walls 23, 25 · Among these ribs, there are ribs extending partially between two longitudinal walls 23, 25 forming the same housing 7, called guide ribs 6 in the following description, and ribs extending at least between two longitudinal walls 23, 25 forming the same housing 7, called stiffening ribs 8. The spacing between two ribs, whether they are guide or stiffening, located on either side other of the insertion path 26 along the transverse axis T, corresponds to the transverse dimension of the heating element 5, apart from the manufacturing clearances.

The stiffening ribs 8 connecting the two longitudinal walls 23, 25 participate in the stiffening of the frame 3 and the heating compartment 3θ · According to the embodiment illustrated in Figures 1 and 2, the guide ribs 6 and the ribs of stiffening 8 extend from an end edge 23a, 23b, 25a, 25b of the internal faces 230a, 250a, and projecting from the corresponding internal face.

According to the invention, and in order to ensure the maintenance in position of each heating element 5 inside its housing 7 between the longitudinal walls 23, 25 participating in delimiting the housing 7, the frame 3 comprises, as has been specified before, at least one holding member configured to extend at least partially across the housing 7 so as to be on the passage of the heating element 5 during its insertion. More specifically, the frame 3 according to the invention comprises at least as many holding members as it comprises housings 7 intended to receive a heating element 5 · In what follows, the holding member or members intended to equip a single housing 7 will be more precisely described, it being understood that the same description can apply to all of the holding members intended to equip all the housing 7 of the frame 3 and of the heating device 1 according to the invention.

FIG. 3 illustrates, in section along a plane parallel to the previously defined vertical longitudinal plane, a portion of a housing 7, delimited vertically by the first longitudinal wall 23 and the second longitudinal wall 25 · According to the invention, the member for holding is a pin 4 configured to be inserted into a receiving orifice 231 arranged in one of the longitudinal walls delimiting the housing, here the first longitudinal wall 23 ·

With reference to this FIG. 3 and to FIG. 4 in which the pin is illustrated alone, the pin 4 has a head 40 which extends projecting inside the housing 7 when the pin is made integral with the corresponding longitudinal wall , as well as a foot 41 which is configured to be placed in the receiving orifice 231 arranged in the longitudinal wall 23 and which is configured to lock the pin in position relative to the frame.

Advantageously, this pin is made in one piece, the head and the foot forming a single piece. The pin is, for example, produced by injection, into a mold, of a material chosen for its deformation properties, both elastic and plastic. By way of nonlimiting example, the pin 4 may be made of a material from the family of elastomers.

The receiving orifice 231 here extends over the entire vertical dimension, or height, of the first longitudinal wall 23 in which it is arranged. In other words, the receiving orifice 231 extends from the internal face 230a of this first longitudinal wall 23 to the external face 230b of this same longitudinal wall, so as to open into each of them. The reception orifice 231 therefore forms a conduit which passes vertically through the longitudinal wall 23 · According to the particularly advantageous, but not exclusive, embodiment illustrated in FIGS. 3 and 4, the reception orifice 231 has an axis of symmetry Y substantially parallel, except for manufacturing tolerances, to the vertical axis V previously defined. According to different variant embodiments, the receiving orifice 231 can be cylindrical with an axis Y, or it can be in the form of a slot extending in a transverse direction, parallel to that of the transverse axis T previously. defined, from one end edge to the other.

The head 40 of the pin 4 has a substantially planar face 4θθ projecting from which extends the foot 41 · In what follows, this substantially planar face 4θθ of the head 40 of the pin 4 will be arbitrarily designated as the lower face 4θθ of the head 40 of the pin 4, it being understood that the lower term in no way prejudges the orientation of the pin 4 and / or of the frame 3 in the motor vehicle in which the heating device 1 is installed.

This substantially planar face 4θθ is intended to be placed against the internal face 230a of the longitudinal wall 23 when the foot 41 of the pin 4 is housed in the receiving orifice 231, forming a stop surface for the insertion of the pin in this receiving port. To do this, it is understood that the lower face 4θθ of the head 4θ of the pin 4 extends so as to at least cover the surface of the receiving orifice 231, so that the peripheral edges of the lower face 4θθ of the head 4θ of the pin 4 come to bear against the internal face 230a of the first longitudinal wall 23 around the edges delimiting the receiving orifice 231 on this first longitudinal wall.

The head of the pin has a convex shape which extends, from its lower face 4θθ> in the direction of the vertical axis V, towards the second longitudinal wall 25 which delimits, with the first longitudinal wall 23, the housing 7 in which the heating element 5 is received. The head 40 of the pin 4 therefore extends vertically within the housing 7 and the insertion path 26. In other words, the head 40 of the pin 4 therefore constitutes an obstacle to the insertion of the heating element 5 in the longitudinal direction L within the insertion path 26.

Advantageously, the head 40 of the pin 4 has an axis of symmetry Y1 substantially coincident, when the pin 4 is inserted in the receiving orifice 231, with the axis of symmetry Y of the latter. Furthermore, according to the non-exclusive embodiment, more particularly illustrated by FIGS. 3 and 4, the shape, from its lower face 400, of the head 40 of the pin 4, is substantially that of a portion of sphere centered on this axis of symmetry Yl. More generally, the dimension, in the direction of the vertical axis V, of the head 40 of the pin 4, is maximum on the axis of symmetry Y of this head, and it decreases towards the edges of it. this. According to other embodiments, not shown, the head 40 of the pin 4 may have a substantially frustoconical profile from its lower face 400, frustoconical profile whose largest diameter is materialized by the peripheral edges of said lower face 400. In other words, the head 40 of the pin 4 forms, in the longitudinal direction L of insertion of the heating element 5 in the housing 7, an inclined surface from the internal face 230a of the longitudinal wall 23, in direction of the second longitudinal wall 25 ·

As previously specified, the foot 41 of the pin 4 is configured to fit into the receiving orifice 231 · In other words, the shapes and dimensions of the foot 41 of the pin 4 are defined complementary to those of the orifice 231, so that the foot 41 of the pin 4 can be inserted easily, but without excessive play, within the reception opening 231 · In the example illustrated, in which the reception opening has a shape cylindrical with an axis Y, the foot 41 of the pin 4 has a shape of a cylindrical barrel, which may have a diameter slightly greater than the diameter of the receiving orifice, so that it is necessary to force fit the foot of the pin in the receiving hole.

The foot 41 is attached to the head 4θ of the pin 4, more precisely to the lower face 4θθ thereof, at one of its ends in the vertical direction V, and it has in the example illustrated a base 42 to the opposite end. Advantageously, the dimension, in the direction of the vertical axis V, of the foot 41 of the pin 4, is defined in such a way that, when this foot 41 is inserted into the receiving orifice 23L on the one hand, the lower face 4θθ of the head 4θ of the pin 4 is placed against the internal face 230a of the longitudinal wall 23 and, on the other hand, the end of the foot 41 opposite the end by which it is attached to the head 40 is flush with the external face 230b of the longitudinal wall 23 · Arbitrarily, in what follows, the end of the foot 4L in the vertical direction V, by which this foot 41 is attached to the underside 400 of the head 40 of the pin 4 will designated as the upper end 410a, and the opposite end of this foot 41 in this same vertical direction V will be designated as the lower end 410b. It goes without saying that these denominations are arbitrarily chosen according to the orientation of the pawn 4 on the representations which are made of it by the different figures and which in no way prejudge the orientation and the arrangement of the pawn 4 and the frame 3 in the motor vehicle equipped with the heating device 1.

Advantageously, the vertical axis of symmetry Y1 of the head 40 of the pin 4 is also an axis of symmetry for the foot 41 of the pin 4 · According to various non-limiting embodiments, the foot 41 of the pin 4 can be cylindrical with an axis Yl, or it may be in the form of a rib extending both in a vertical direction parallel to that of the vertical axis V previously defined and in a transverse direction parallel to that of the transverse axis T.

When the heating element 5 is inserted, in the longitudinal direction L, into the housing 7, along the insertion path 26, its front end, that is to say the first of its ends to be inserted in the housing 7, first of all abuts against the head 40 of the pin 4 · 11 is then necessary to exert a longitudinal constraint to allow the crossing, by the heating element 5, of the vertical obstacle which constitutes the head 40 of the pin 4 on the insertion path 26. The inclined shape of this head along, in particular, the longitudinal direction, makes it possible to facilitate this crossing, while limiting the risks of tearing of the pin 4 and of entrainment thereof in the longitudinal sliding movement of the heating element 5 · The elastic deformation capacity of the material chosen to make the pin 4 also makes it possible to facilitate this crossing.

Once the obstacle formed by the head 40 of the pin 4 has been crossed in the housing 7, the heating element 5 is sandwiched between the second longitudinal wall 25 and the head 40 of the pin 4 · The elastic properties of the material which constitutes this head 40 force the head to return to its original position and therefore to exert a vertical stress on the heating element 5, maintaining the latter in this vertical direction within the housing 7, it being understood that the maintenance of the heating element in the transverse direction is provided by the ribs for guiding and stiffening respectively 6, 8, previously defined, against which the heating element slides longitudinally during its insertion along the insertion path 26.

In order to further reduce the risks of the pin 4 being torn off and entrained from the receiving orifice 231 during the longitudinal sliding of the insertion of the heating element 5 along the insertion path 26, the pin 4 has a base 42 configured so that, when the pin 4 is made integral with the corresponding longitudinal wall by cooperation of the foot 41 in the receiving orifice 23L, this longitudinal wall 23 is sandwiched, or sandwiched, between this base 42 and the head 40 of the pawn 4 ·

The base 42 of the pin 4 extends, from the lower end 410b of the foot 4L, that is to say the end opposite to the head 40, by extending this foot 41 both transversely and longitudinally. More particularly, as illustrated in FIGS. 3 and 4, the base 42 has a face 420 extending perpendicularly the lower end 410b of the foot 4L, the face 420 being advantageously flat so as to be placed against the external face 230b of the longitudinal wall 23 when the pin 4 is inserted into the receiving orifice 231 · Arbitrarily, this face 420 will be designated in the following as upper face 420 of the base 42, it being understood that this term is arbitrary and that it in no way prejudges of the orientation of the base 42 and of the pin 4 within the frame 3 in the motor vehicle equipped with the heating device 1. 11 results from the above that the upper face 420 of the base 42 and the lower face 400 of the head 40 are parallel or substantially parallel to each other.

The base 42 has a symmetry along the vertical axis of symmetry Y1 of the pin 4 · According to different exemplary embodiments, the base 42 of the pin 4 may or may not have a symmetry of revolution around this vertical axis Yl.

Furthermore, in this illustrated embodiment, the base 42 of the pin 4 has a substantially frustoconical shape whose largest diameter is located, in the vertical direction, at the upper face 420 of the base 42. Alternatively, the base 42 may, by way of nonlimiting example, have the shape of a portion of a sphere centered on the vertical axis of symmetry Yl of the pin 4 · In general, the dimension, in the vertical direction V, of the base 42, is advantageously maximum at the level of the upper face 420, and it decreases progressively towards the free end of base 42, so that the base 42 of pin 4 has, in the longitudinal direction L, an inclined ramp profile .

The pin 4 further comprises an opening 43 which extends from the lower end 421 of the opposite base 42, in the vertical direction T, at the end by which this base is attached to the foot 41 · En d ' in other words, this lower end 421 corresponds to the free end of the base. The opening 43 extends, in the vertical direction V, from the face defining the lower end 421 of the base 42, in the direction of the head 4θ of the pin 4> at least through the base 42 and in the case illustrated through the foot 41 in continuity. Advantageously, the vertical axis of symmetry Y1 of the foot 4L of the head 4θ and of the base 42 of the pin 4 is also an axis of symmetry for the opening 43 · According to various embodiments of the invention, non-limiting, the opening 43 may be cylindrical with an axis Yl, or it may have any other shape. According to the embodiment more particularly illustrated by FIGS. 3 and 4> the opening 43 is delimited, in the vertical direction V, by a bottom wall 43θ> substantially parallel to the upper face 420 of the base 42 and to the underside 400 of the head 40 of the pin 4 ·

The combination of the material with elastic properties used for the design of the pin 4, and in particular of the base 42, and the presence of this opening 43 allows an elastic deformation of the base and in particular a bringing together of the edges of this base to reduce the general dimensions and allow the insertion of the base into the receiving orifice as will now be described.

The insertion of the pin 4 into the receiving orifice 231 is done in the following manner. The base 42 projecting from the foot 41 of the pin 4 is first of all presented in front of the receiving orifice 23L more precisely on the side of the internal face 230a of the longitudinal wall 23 in which this receiving orifice is arranged. More precisely, taking into account the respective dimensions, in particular in the longitudinal direction L, of the receiving orifice 231 and of the base 42, the inclined walls of this base 42 are then placed against the edges delimiting the hole 231a by which the the receiving orifice 231 opens into the internal face 230a of the longitudinal wall 23 · When the operator exerts, on the pin 4, a force in a direction illustrated by the arrow E in FIG. 3> parallel to the vertical direction V, to insert the pin 4 into the receiving hole 23L, the particular profile of the base 42, combined with the properties, in particular elastic properties, of the material chosen to make the pin 4, lead to a deformation of the base 42 whose lower end 421 can then engage at least partially in the conduit formed by the receiving orifice 231 in the thickness of the longitudinal wall 23 · The inclined ramp profile that this base has allows the insertion of the pin to continue through the longitudinal wall with less effort to be provided by the operator. The presence of the opening 43. combined with the elastic properties of the material chosen to make the pin 4, leads to an additional deformation of the base 42 and, in particular, to an approximation towards the vertical axis of symmetry Yl of the pin 4, walls which delimit, along the vertical direction V, the opening 43 and, therefore, a form of tightening of the base 42 of the pin 4 around the vertical axis of symmetry Yl thereof, and the case due to a form of tightening of the foot 41 of the pin around this same axis Yl. 11 follows that it becomes possible to insert the entire base 42, deformed, within the receiving orifice 23L, until the edges of the upper face 420 thereof have crossed the edges of the hole 231b through which the receiving orifice 231 opens into the external face 230b of the longitudinal wall 23 · Released from the stresses exerted, in particular in the longitudinal direction L, by the walls which delimit the receiving orifice 23L the base 42 and the opening 43 then return elastically, thanks to the mechanical properties of the material chosen to produce the pin 4, to their initial shapes and dimensions. 11 then results from the dimensions, in particular in the vertical direction V, of the leg 4L and of the dimensions, in particular along the longitudinal direction L, of the head 4θ and of the base 42 of the pin 4, that the longitudinal wall 23 is then taken in sandwich between the lower face 4θθ of the head 4θ and the upper face 420 of the base 42 of the pin 4 · The latter is thus blocked, in the vertical direction V, in the receiving orifice 23L which further reduces the risks of tearing during the insertion, along the insertion path 26, of the heating element 5 in the housing 7 ·

In the foregoing, the pin 4 has been described by its characteristics in particular along the vertical V and longitudinal L directions of the trihedron L, V, T, previously defined. According to the embodiments of the invention in which the pin 4 has a symmetry of revolution about its vertical axis of symmetry Yl, the characteristics and particularities that the pin 4 has in the longitudinal direction L can be transposed in a similar manner to the transverse direction T. According to the embodiments which have just been described and which are illustrated by FIGS. 3 and 4, it should be noted that the pin 4 has a dimension in the transverse direction T previously defined which is less than the dimension in the same direction of the longitudinal wall 23 in which the receiving orifice 231 is arranged.

Figure 5 shows an alternative embodiment of the invention. With reference to this figure, the head 4θ of pin 4 extends over the entire width, that is to say the dimension, in the transverse direction T, of the longitudinal wall 23 · The pin 4 has here a plane of symmetry substantially parallel both to the transverse axis T and to the vertical axis V, and containing the axis of symmetry Yl previously defined. The head 4θ then forms a bead which extends vertically across the insertion path 26 and the longitudinal wall 23, perpendicular to this longitudinal wall 23 · 11 should be noted that, in this case, the receiving orifice 231 will advantageously take the form of a slot arranged, in the transverse direction T, over a major part of the longitudinal wall 23 · However, in order to avoid excessive embrittlement of the latter, this slot will advantageously only extend partially over the transverse dimension of this longitudinal wall 23 · Similarly, in this case, the foot 41 of the pin 4 will advantageously be in the form of a rib configured to fit into the slot formed by the receiving orifice 231 ·

Such a configuration makes it possible to further reduce the risks of the pin 4 tearing out of the longitudinal wall 23 when the heating element 5 is put in place along the insertion path 26. In fact, the head 4θ of the pin 4 having a larger volume, the longitudinal stress to be exerted to take off the lower face 4θθ of this head from the internal face 230a of the longitudinal wall 23 against which it is pressed, when the pin 4 is inserted in the receiving orifice 231 , will be greater than in a configuration in which the volume occupied by the head 40 on the longitudinal wall 23 is less.

Such a configuration also allows a distribution, in the transverse direction parallel to the axis T, of the compressive stress exerted vertically by the head 40 of the pin 4 on the heating element 5 once it has been put in place. in the housing 7 · This allows, on the one hand, to avoid any risk of partial deflection of the heating element in the housing 7, which could lead to generating parasitic noise. It is in fact understood that, as a function of the intended mounting clearances and the respective manufacturing tolerances of the heating element 5 and of the frame 3, it is possible, depending on the location, in the transverse direction of axis T, of the receiving orifice 231 and depending on the size, still in this transverse direction, of the head 4θ of the pin 4 on the longitudinal wall 23, that a residual clearance, potential source of relative movement of the heating element 5 within the frame 3, remains, for example at the edges 23a, 23b, previously defined, between the frame 3 and the heating element 5, once the latter installed in its housing 7 ·

As specified above, such a configuration allows a distribution of the compressive stress exerted transversely by the pin 4 on said heating element 5 · This makes it possible to limit the risks, over time, of localized damage, of the heating element 5 under the effect of this permanent mechanical stress, thus increasing the life of the heating device 1.

According to the invention, the arrangement and the number of pins 4 within the same housing 7 are also of particular importance. Thus, according to a particularly advantageous variant, but not exclusive, the invention can provide that several receiving orifices 231 and corresponding pins 4 can be configured within the frame 3 · 11 goes without saying, in this case, that the orifices 231 reception and 4 associated pins may all be identical or may have different characteristics described above, taken separately or in combination, without this harming the invention: for example, it is entirely conceivable, in this case, that some of the pins 4 arranged in the same housing 7 extend over the entire dimension, in the transverse direction T, of the longitudinal wall 23, while others occupy only partially this dimension. Similarly, in the longitudinal direction L, the pins and associated receiving holes 231 may, for all or part, be successively aligned or successively staggered relative to the median plane of the frame 3 previously defined. Finally, in the vertical direction T, the heads 4θ of the different pins 4 may or may not have the same dimension, or thickness: it is, by way of nonlimiting example, quite conceivable, without harming the invention , that the thickness of the heads 4θ of the different pins 4 configured inside the same housing 7 increases, in the longitudinal direction, from the opening 5θ> previously defined, of the insertion path 26, through which the heating element 5 is introduced into said housing 7, towards the stops 210 of the bottom wall 21 against which said heating element 5 is placed when it is inserted into its housing 7 ·

Whatever their number and their relative arrangement in the longitudinal direction L, the invention provides that at least one of the pins 4 and associated receiving orifices 231 is arranged in the vicinity of the bottom wall 21 previously defined.

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. their accommodation 7 ·

The invention as it has just been described, however, cannot be limited to the means and configurations exclusively described and illustrated, and it also applies to all equivalent means or configurations, as well as to any combination of such means or configurations. . In particular, if the invention has been described and illustrated here in a case where receiving orifices 231 and associated pins 4 are configured on the first longitudinal wall 23 of a housing 7, it goes without saying that the invention applies also in the case where these reception orifices and associated pins are configured on the second longitudinal wall 25 of such a housing 7, and that it also applies to the case in which reception orifices and associated pins are configured on each of these walls.

Claims (10)

1. Frame (3) of an electric heating device (1) of an air flow circulating inside a ventilation, heating and / or air conditioning installation of a motor vehicle, said frame (3) comprising at least one heating compartment (30) having at least one housing (7) intended to receive a heating element (5), the housing (7) being defined at least by two longitudinal walls (23, 25) delimiting vertically an insertion path (26) for the heating element (5), each longitudinal wall (23, 25) comprising an internal face (230a, 250a) oriented towards the insertion path, characterized in that the frame ( 3) comprises at least one member for holding in position the cbauffant element (5) in the housing (7). 2. Frame (3) according to claim 1, characterized in that the holding member comprises at least one pin (4) configured to be inserted in a receiving orifice (231) arranged in one of the longitudinal walls (23 , 25). 3. Frame (3) according to the preceding claim, characterized in that the pin (4) comprises a head (40) intended to extend vertically projecting inside the housing (7) in which the cbauffant element ( 5) is received and a foot (41) intended to be inserted into the receiving orifice (231) arranged in the longitudinal wall (23, 25) · 4. Frame (3) according to the preceding claim, characterized in that the dimension, in particular longitudinal, of a lower face (4θθ) of the head (40) of the pin (4) is greater than the dimension, in particular longitudinal, of the receiving orifice (231) 5. Frame (3) according to one of claims 3 or 4> characterized in that the pin (4) has a base (42) which extends, vertically, opposite the head (40) relative at the foot (41), the base (42) being configured so that the longitudinal wall (23, 25) in which the receiving orifice (231) is arranged is sandwiched between the lower face (4θθ) of the head (40) and an upper face (420) of said base (42). 6. Frame (3) according to one of claims 3 to 5> characterized in that the foot (41) of the pin (4) has an opening (43) configured to allow deformation, in particular longitudinal, of said foot (41) during its insertion into the receiving orifice (231) · 7. Frame (3) according to any one of claims 2 to 6, characterized in that the 5 pin (4) extends over the entire transverse dimension of the longitudinal wall (23, 25) in which the receiving orifice (231) is arranged · 8. Frame (3) according to any one of claims 2 to 7, characterized in that the holding member comprises at least two receiving orifices (231) and associated pins (4) 10 distributed over the longitudinal dimension of the longitudinal wall (23, 25) · 9. Frame (3) according to any one of claims 2 to 8, characterized in that the receiving orifice (231) is arranged in the vicinity of a bottom wall (21) of the housing (7). 15 10. Electric heating device (1) of an air flow circulating inside a ventilation, heating and / or air conditioning installation of a motor vehicle, characterized in that it comprises at least a heating element (5) received in a housing (7) of a frame (3) according to any one of the preceding claims.