FR2954468A1 - ELECTRIC HEATING DEVICE AND CORRESPONDING ASSEMBLY METHOD - Google Patents

Abstract

The invention relates to an electric heating device for heating an air flow therethrough, said heating device comprising: a predetermined number of electric heating modules (23) intended to be traversed by the flow of air to be heated and having first electrical terminals (45) to be electrically powered, and - a control box (47) of said heating modules (23) comprising second electrical terminals (51) connected on the one hand to said first terminals (45) and configured to be connected on the other hand to a power source for electrically powering said first terminals (45). According to the invention, the control unit (47) further comprises means (53) for positioning said heating modules (23) with respect to said housing (47) to delimit an appropriate operating position before connecting said first (45) and second (51) terminals during assembly of said heater. The invention also relates to a method of assembling such a device.

Description

The invention relates to an electric heating device intended to be traversed by a flow of air to be heated. The invention also relates to a method of assembling 5 such a heater. Such an electric heating device, otherwise called additional electric radiator, is generally mounted in an air circulation duct to be heated downstream of a heat exchanger to heat the air intended for heating the passenger compartment of a vehicle. and defogging and defrosting by heat exchange between a flow of air passing through the heat exchanger and a liquid, usually the engine coolant. The electric heater includes heating modules arranged to be exposed directly to the air passing through the heater to provide almost immediate heat build-up when heat-up by the heat exchanger is insufficient. The operation of the electric heater is temporarily controlled until the heat exchanger alone can provide adequate air heating. Control of the heater is provided by an electrical supply circuit mounted for example on a printed circuit board in a control box on the heater. This power supply circuit is connected to a power source and is further connected to the electrical terminals of the heating modules. For this purpose, the electrical terminals of the heating modules are connected to corresponding electrical terminals connected to the power supply circuit. However, during the assembly of the heating device, the movement to connect the corresponding electrical terminals is not limited and it has been found that the electrical terminals connected to the supply circuit can be put in strain as well as the supply circuit causing mechanical stress on the printed circuit, which should be avoided. The purpose of the invention is therefore to overcome this drawback of the prior art. To this end, the subject of the invention is an electric heating device for heating an air flow therethrough, said heating device comprising: a predetermined number of electric heating modules intended to be traversed by the flow of air to be heated and having first electrical terminals to be electrically powered, and a control box of said heating modules having second electrical terminals connected on the one hand to said first terminals and configured to be connected on the other hand to a power source for electrically powering said first terminals, characterized in that the control box further comprises means for positioning said heating modules relative to said housing to delimit an adequate operating position before connecting said first and second terminals during assembly of said heating device .

The positioning means therefore make it possible to limit the assembly movement of the electric heating modules to the control box when the heating modules are correctly positioned, thus avoiding stressing the electrical terminals of the control box. Said heating device may further comprise one or more of the following characteristics, taken separately or in combination: the positioning means are made in one piece with said housing, the positioning means comprise positioning stops against which said heating modules are supported, via an edge of the heating module, to define the appropriate positioning of said first terminals with respect to said second terminals, said heating device comprises a frame for holding said heating modules and the positioning means comprise guiding members configured to fit into complementary guide sleeves provided on the frame, the guide members are arranged parallel to said second terminals and that the positioning stops are formed by protuberances on the guide members extending towards said second terminals, the guide members respectively have a substantially parallelepipedal general shape with a window in which extends longitudinally a guide pin 5, the positioning means comprise clipping teeth configured to cooperate with clipping against-teeth provided on the frame, the clipping teeth are carried by the free ends of the guide fingers, the clipping teeth respectively have a height greater than or equal to the height of the counter-clipping teeth. The invention also relates to a method of assembling a heating device as defined above characterized in that it comprises the following steps: placing the first electrical terminals of said heating modules on the second electrical terminals of the control unit, said heating modules are positioned relative to said housing so that said heating modules are in abutment against the positioning stops, and the frame and said housing are fixed. Said assembly method may further comprise one or more of the following characteristics, taken separately or in combination: a translation of said heating modules in the direction of said housing until said heating modules bear against said stops, is carried out a translation of said housing in the direction of said heating modules until said stops abut against said heating modules, the heating modules are translated into receiving housings configured in the frame by pressing the stops on the edge of the heating module, said assembly method comprises a step in which the guide members are inserted into the complementary guide sleeves over a predefined guide distance during which the clipping teeth terminating the guide fingers remain free, and the clipping teeth are placed against the counter-teeth of TFR0757 2954468 -4- r fixing the frame and said housing by clipping, said assembly method comprises a preliminary step in which a rotation of the frame to place said first terminals on said second terminals. Other features and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and nonlimiting example, and the appended drawings in which: FIG. 1 is a schematic partial view of a heater for a motor vehicle, Figure 2 illustrates an electric heater of the heater of Figure 1, Figure 3 shows an embodiment of a heating module of the heater, Figure 4a. Fig. 4b is a partial perspective view of Fig. 4a, Fig. 4c is another partial perspective view of the heating device of Fig. 2 before assembly of the frame and the control box of said heater. FIG. 4a shows a partial view of the assembled heater of FIG. 2, FIG. 6 is a partial side view of FIG. 4a, FIG. st a partial view in longitudinal section of the heating device of FIG. 2 before fixing the frame and the housing of said heating device, and FIG. 8 is a partial view in longitudinal section of the heating device of FIG. frame and housing of said heater.

In these figures, the substantially identical elements bear the same references. Figure 1 shows a part of a heater and / or air conditioning 1 of a motor vehicle, comprising a housing 3 defining a channel 5 for the passage of the air flow to be heated. The channel 5 brings the air to the heating and defogging / defrosting vents 7,9 to be selectively distributed in the passenger compartment according to the mixing and distribution flaps 11. The air flow rate in the channel 5 is produced by a fan 13, or blower, receiving outside air or circulating air from the passenger compartment. The heating of the air, when necessary, is provided by an optional liquid heat exchanger 15, using the engine coolant as a coolant and by an electric heater 17, otherwise known as an electric heater. The exchanger 15 and the electric heater 17 are arranged in the channel 5, the first being located upstream of the second. In the absence of exchanger 15, the heating of the air is provided by the single electric heating device 17.

With reference to FIG. 2, such an electric heating device 17 comprises a heating block 19 having a generally parallelepiped-shaped frame 21, receiving electric heating modules 23 arranged so as to be traversed by the air flow through. warm up. Such an electric heater 17 can reach high temperatures during operation, for example of the order of 150 ° C, the frame 21 is made of a material, for example plastic, able to withstand these high temperatures reached in operation. These heating modules 23 are arranged parallel to each other and extend over the entire length of the frame 21 by being received in receiving housings 25 formed in the frame 21, these housings 25 being delimited in the illustrated example by longitudinal walls 27 of the frame 21. The heating modules 23 are for example interposed between perforated zones of the frame 21. The frame 21 has flexible tongues 31 for exerting a friction force on the heating module 23 during the insertion of the module 23 for this purpose, the tabs 31 form a non-zero angle with respect to the direction of insertion of the heating modules 23 in the housing 25. In addition, it can be provided that some of the longitudinal walls 27 delimiting the housings 25 for the heating modules 23, have at least one projection 33, 30 extending towards the interior of the housing 25, in such a way as to guide the heating module 23 when it is inserted into the housing 25 and its retention in the housing 25 once inserted. The frame 21 may also have guide ribs 35, for example in an "X" shape to enable the heating modules 23 to be guided during their insertion into the housings 25 and also to be retained once inserted. Furthermore, a heating module 23 may comprise resistive elements of positive temperature coefficient (PTC) type. These elements are protected against overheating or overcurrent. According to an alternative embodiment illustrated in FIG. 3, a heating module 23 comprises two electrodes 39 which extend longitudinally, each enclosing a heat sink 41 formed, for example, of a pleated or corrugated metal strip and bearing against the elements 43 For the sake of clarity, the heat sink 41 is not shown in full in FIG. 3. Of course, the heat sink 41 extends over the entire length in the electrode 39.

According to another alternative embodiment of the heating module 23 (not shown), the electrodes sandwich the resistive elements while the heat sinks formed by the metal ribbon are placed against the free outer faces of said electrodes. In other words, the heating module 23 consists of two heat sinks which enclose two electrodes between which 20 are placed CTP stones or resistive elements. The two electrodes 39 of a heating module 23 are traversed, by means of two first electrical terminals 45, by different electrical potentials, for example a first potential available in the vehicle, such as the battery voltage, and a second potential, such as mass.

In the example illustrated in FIG. 2, when three heating modules 23 are provided, there is then a row of six first terminals 45 to supply electrical energy. Control of the electric heater 17 is therefore provided by a power supply circuit (not shown) of the heating modules 23 mounted on one side of the frame 21 in a control box 47 otherwise called "driver". TFR0757 2954468 -7- The power supply circuit is mounted for example on a printed circuit board. This power supply circuit is connected to a power supply source via two metal conductors 49 and 49 ', also called "bus bars", of which a first 49 can be set to the first potential, and the second 49 'to the second potential. The power supply circuit can receive information on the power to be delivered through a connector 50. By way of example, the power supply circuit comprises transistors (not shown) to enable or disable the passage of current in the heating modules 23.

In addition, second electrical terminals 51 connected to the electrical supply circuit conduct the electric current to the corresponding first electrical terminals 45 of the heating modules 23 when the transistor concerned allows the passage of current. In the example illustrated in which the electric heating device 17 comprises three heating modules 23, six second electrical terminals 51 are provided for supplying power to the first six corresponding terminals 45 of the heating modules 23. The housing 47 further comprises means 53 of the heating modules better visible in Figures 4a to 4c. These positioning means 53 comprise in the illustrated example positioning stops 55 to limit the assembly movement, here a translation, and define the appropriate operating position of the terminals 45 and 51 relative to each other. For this purpose, the stops 55 extend towards the second terminals 51. According to the illustrated embodiment, a first stop 55 is above a terminal 51 and a second stop 55 is below the other terminal 51. for a better recovery of forces. As can be seen in FIG. 5, when the heating modules 23 are in abutment against the stops 55, a constant clearance is defined between the second terminals 51 and the heating modules 23.

Furthermore, referring again to FIGS. 4a to 4c, the positioning means 53 may also comprise guide members 57 for centering the frame 21 relative to the housing 47. These guide members 57 cooperate with each other. with complementary guide sleeves 59 provided on the frame 21. Specifically, the guide members 57 5 are inserted into the sleeves 59 complementary assembly of the frame 21 and the housing 47. These guide members 47 provide a centering side of the frame 21 (Figure 5) and a centering in the thickness (Figure 6). For this, the guide members 47 have slightly smaller dimensions than the complementary sleeves 49 10 to allow the insertion of the guide members 47 in the sleeves 49 complementary. In this case, the positioning means 53 thus make it possible both to guide and center the frame 21 before attaching it to the casing 47 as well as to function correctly positioning the electrical terminals 45 and 51 with respect to the other. In addition, according to the embodiment described, the guide members 57 are arranged parallel to the second terminals 51 and the stops 55 are formed by protuberances on the guide members 57 which extend towards the second terminals 51.

In addition, in the example illustrated in FIGS. 4a to 4c, the guide members 57 respectively have a substantially parallelepipedal shape with a window 61 in which a guide finger 63 extends longitudinally. According to the embodiment shown, each guide pin 63 ends at its free end by a clipping tooth 65 better visible in Figure 7. This clipping tooth 65 is configured to cooperate with a clipping against-tooth 67 provided in the sleeve 59 complementary to the guide member 57. These teeth 65 and counter-teeth 67 allow clipping attachment of the frame 21 and the housing 47. For this purpose, the teeth 65 have a height h greater than or equal to the height h 'against the teeth 67.

The teeth 65 being carried by the guide fingers 63, the latter have a length sufficient for that during the insertion of the guide members 57 into the complementary sleeves 59, the teeth 65 remain unconstrained on a guide distance d predefined, until abutting against the against-teeth 67 (Figure 7) and overlap to lead in the example shown in Figure 8, in a window 69 5 of the sleeves 59 complementary. The positioning means 53 thus still provide a third function of fixing the frame 21 and the housing 47. In the example described, the fixing of the frame 21 and the housing 47 is done by clipping, of course, any other variant of fixation.

In addition, it can be provided that the control unit 47 is formed of two half-housings fixed together, for example by clipping. In this case, each positioning means 53 is formed of two half-parts made respectively in one piece with an associated half-casing of the casing 47. The two half-parts of a positioning means 53 are fixed between them. , for example by clipping using a clipping means as seen in Figures 5, 7 and 8. This clipping means may be a clipping tab 71 carried by a half portion of the positioning means 53 which engages in an associated orifice provided on the other half-part of the positioning means 53. Moreover, referring again to FIG. 2, it can be seen that the heating device 17 may comprise a heel 73 on the side of the frame 21 opposite the side carrying the control box 47, and formed integrally with the frame 21 for example by molding. This heel 73 forms a lateral closure of the housings 25 of the heating modules 23 in the frame 21.

The heel 73 may comprise openings 75 intended to be traversed by the flow of air to be heated in order to balance the pressure drops, and to avoid temperature differences at the outlet of the electric heating device 17. This heel 73 may also have a hollow tubular shape which allows the heel 73 to be placed on an associated assembly support (not shown) for the assembly of the heating device 17. Such an assembly support may comprise a rotary base (not shown in FIG. shown) which engages in the hollow heel 73 so as to be able to rotate the frame 21 to place the first terminals 45 on the second terminals 51 and avoid an improper overlap of the terminals 45 and 51 or a frontal impact when the 'assembly.

Thus, the assembly of the heater 17 is carried out as follows. In a first step (FIG. 4a), the first electrical terminals 45 of the heating modules 23 are placed on the electrical terminals 51 of the housing 47 and the heating modules 23 are positioned in a predefined operating position with respect to the housing 47 more precisely relative to the second electrical terminals 51 by placing the heating modules 23 in abutment against the stops 55 of the positioning means 53 provided on the housing 47. To do this, the heating modules 23 are pushed in translation movement towards the housing 47 or conversely the housing 47 is pushed in a translation movement towards the heating modules 23. In both cases, the translational movement is implemented by the support of the stops 55 on the edge 100 of the module 23. Then, the frame 21 and the housing 47 are fixed, for example by clipping. For this purpose, the guide members 57 are inserted into the complementary guide sleeves 59 in order to center the frame 21 over a distance d (FIG. 7) until the clipping teeth 65 cooperate with the clipping counter-teeth. 67 (Figure 8). We can then connect the terminals 45 and 51 for example by welding or by clinching thus obtaining a clinching point 77 (Figure 2). This assembly method may comprise a preliminary step in which the housing 47, for example previously assembled, is positioned on an assembly support 25 and in which the heel 73 is placed on a rotary base enabling the frame to be rotated. 21 towards the housing 47 so that the first terminals 45 are placed above the second terminals 51 in the figures illustrated. The assembly method may further comprise a step in which the heating modules 23 are inserted into the housings 25 of the frame 21, the TFR0757 -11- heating modules 23 being guided by the protrusions 33 or the guide ribs 35. Of course, the order of the steps of this method of assembling the heater 17 can be reversed. It will thus be understood that the positioning means 53 carried by the housing 47 make it easier to assemble the heating device 17, more specifically the assembly of the frame 21 with the housing 47 and the connection of the corresponding electrical terminals 45 and 51, guaranteeing a good positioning of these. TFR0757

Claims (10)

REVENDICATIONS1. Electrical heating device for heating an air flow therethrough, said heating device comprising: a predetermined number of electric heating modules (23) intended to be traversed by the flow of air to be heated and having first terminals (45) electrically powered electrically and a control box (47) of said heating modules (23) having second terminals (51) electrical connected firstly to said first terminals (45) and configured to be connected to a source power supply unit for electrically powering said first terminals (45), characterized in that the control unit (47) further comprises means (53) for positioning said heating modules (23) relative to said housing (47) to delimit a proper operating position before connecting said first (45) and second (51) terminals during assembly of said chopper device; auffage. 2. Heating device according to claim 1, characterized in that the positioning means (53) are made in one piece with said housing (47). 3. Heating device according to one of claims 1 or 2, characterized in that the positioning means (53) comprise stops (55) for positioning against which said heating modules (23) are supported to define the appropriate positioning said first terminals (45) with respect to said second terminals (51). 4. Heating device according to any one of claims 1 to 3, characterized in that said heater comprises a frame (21) for holding said heating modules (23) and in that the positioning means (53) comprise guide members (57) configured to fit into complementary guide sleeves (59) provided on the frame (21). TFR0757 2954468 -13- 5. Heating device according to claim 3 taken in combination with claim 4, characterized in that the guide members (57) are arranged parallel to said second terminals (51) and in that the positioning stops (55) are formed by protuberances on the guide members (57) extending to said second terminals (51). 6. Heating device according to one of claims 4 or 5, characterized in that the guide members (57) respectively have a substantially parallelepipedal overall shape with a window (61) in which extends longitudinally a guide pin ( 63). 10 7. Heating device according to any one of claims 4 to 6, characterized in that the positioning means (53) comprise clipping teeth (65) configured to cooperate with clipping against-teeth (67) provided on the frame (21). 8. Heating device according to claim 6 taken in combination with claim 7, characterized in that the clipping teeth (65) are carried by the free ends of the guide fingers (63). 9. Heating device according to one of claims 7 or 8, characterized in that the clipping teeth (65) respectively have a height (h) greater than or equal to the height (h ') of the clipping of teeth ( 67). 20 10. A method of assembling an electric heater according to claim 3 taken in combination with any one of claims 4 to 9, characterized in that it comprises the following steps: the first electrical terminals (45 ) of said heating modules (23) on the second electrical terminals (51) of the control box (47), said heating modules (23) are positioned relative to said housing (47) so that said heating modules (23) being in abutment against the positioning stops (55), the heating modules (23) are translated into housings (25) configured in the frame (21) by pressing the stops (55) on an edge (100) of a At the end of the heating module (23), the guide members (57) are inserted into the complementary guide sleeves (59), in particular by placing the clipping teeth (65) against the clipping-in teeth. (67) to secure the frame (21) and ledi t case (47). TFR0757