FR3075326A1 - HEATING DEVICE FOR AN AIR CONDITIONING UNIT, IN PARTICULAR A MOTOR VEHICLE, AND AIR CONDITIONING UNIT EQUIPPED WITH SUCH A HEATING DEVICE - Google Patents

Abstract

 The invention relates to a heating device for an air conditioning unit, said heating device comprising a heating body (10) supplied with current for heating an air flow passing through said heating body (10), the heating body (10 ) comprising one or more heating elements, traversed by said current, the said heating element or elements being situated inside one or more housings (12) of said heating body (10) for electrically insulating the said element or elements heats from the outside, said device comprising a support, ensuring at least partial closure of said housing (s) (12), and one or more seals (30, 30 ′) attached to said support to seal the closure of the or housings (12).

Description

The present invention relates to a heating device for an air conditioning unit and an air conditioning unit equipped with such a heating device. It will find its applications, in particular, in the field of motor vehicles.

Electric heating devices are known which are intended to be integrated into vehicle air conditioning units. These are either additional radiators, combined with heating radiators through which a heat transfer fluid flows, in vehicles with an internal combustion engine, or main radiators, in electric or hybrid vehicles.

Such heating devices include a heating body accommodating heating units provided with heating elements supplied with electric current by electrodes. For electrical safety reasons, it may be necessary to isolate the heating elements and their supply electrodes from the outside. For this, the heating units include tubes, electrically insulating, inside which the heating elements and their electrode are located.

However, these tubes are open at each of their longitudinal ends. In use, liquids, especially water, are therefore likely to enter the interior of the tubes, which should be avoided. They thus planned to close the tubes at their ends, this in a sealed manner, using seals.

Currently, the seals are positioned individually, between the ends of the tubes and the components of the heating device used to close said tubes, simultaneously with the assembly of the assembly. Such solutions pose many problems, in particular the time required for assembly and the correct positioning of the seals. However, proper positioning of the joints is critical to ensure satisfactory sealing of the closure of the tubes and, consequently, good electrical insulation of the current-conducting components which they contain.

The invention aims to at least partially overcome the drawbacks mentioned above and for this purpose provides a heating device for air conditioning unit, said heating device comprising a heating body supplied with current to heat an air flow passing through said heating body, the heating body comprising one or more heating elements, traversed by said current, the said heating element or elements being located inside one or more housings of said heating body to electrically isolate the or said heating elements from the outside, said device comprising a support, ensuring at least partial closure of said housing (s), and one or more seals attached to said support to seal the closure of housing (s).

Thus, according to the invention, by predisposing the joint (s) on the support used to close the housing (s), it facilitates the mounting and the correct positioning of the joints. In particular, it is no longer necessary to mount them individually, which makes it possible to speed up and make the assembly of the device more reliable.

According to other characteristics of the invention which can be taken together or separately:

- the said housing (s) are respectively formed of a tube or tubes,

- the said tube or tubes are sealed in at least one of their longitudinal ends by the said support with the aid of one of the said joints,

said device comprises a distribution and / or control unit for the current flowing in said heating body,

- at least one of the joints, called the first joint, is located:

- heating element side, or

- on the current distribution and / or control unit side, said heating body or said distribution and / or control unit thus forming a first part of the support,

said first part of the support closes a first longitudinal end of said tubes,

said heating body comprises a frame for holding said housings,

- said frame is formed in one piece,

- as a variant, said frame of several separate elements,

- said frame is provided with an upright, said to be proximal, situated opposite said distribution and / or control unit,

- said first seal is attached to said proximal upright,

- said distribution and / or control unit comprises a box provided with a face for connection to the heating body,

- said first seal is attached to said connection face,

- said first part of the support comprises orifices for the passage of electrodes for supplying the heating elements,

the electrodes have ends opening into the housing,

- said ends form male connectors,

- said first seal includes lights for passage of the supply electrodes,

- said openings have a constant cross section along a thickness of the joint or increasing or decreasing in the direction of the orifices for passage of the electrodes,

- the cross section of the lights at one face of the first seal facing said orifices for passage of the supply electrodes is identical, smaller or higher than the cross section of said passage orifices,

- the lights are located opposite said orifices for passage of the supply electrodes,

- said first seal extends between said orifices for passage of the supply electrodes,

- at least one of the seals, said second seal, is located on said frame, said frame thus forming a second part of said support,

said second part of the support closes a second longitudinal end of said tubes,

said frame comprises an upright, said to be distal, facing which opens said tube or tubes by their second longitudinal end,

- said second seal is located at said distal post,

said frame also comprises two lateral uprights, connected to each other by said distal upright,

- said lateral uprights are fixed to the connection face,

- said second joint extends continuously over said distal post,

said device comprises means for fixing the heating body allowing compression of the joint (s) on their support,

- said seal is formed with the support by overmolding and / or by biinjection,

said seal is fixed to said support by gluing and / or mechanical attachment,

- Said seal is made of elastomeric material, silicone and / or foam.

The invention also relates to an air conditioning unit comprising a heating device as described above.

The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of non-limiting example and with reference to the appended drawings in which:

- Figure 1 schematically illustrates a front view of a heating device according to the invention,

FIG. 2 schematically illustrates a front view of a variant of the heating device according to the invention,

FIG. 3 schematically illustrates a front view of part of the heating body of a device according to the invention,

FIG. 4 illustrates in cross-sectional view a tube of a heating device according to the invention,

- Figures 5a, 5b and 5c are sectional views of the seal and the support of a heating device according to the invention, the sectional view being oriented along the section line illustrated in Figures 6 and 7, this according to different variants,

- Figure 6 schematically illustrates in side view the heater of Figure 3 with a seal according to a first embodiment of the invention,

- Figure 7 schematically illustrates in side view the heater body of Figure 3 with a seal according to a second embodiment of the invention.

As illustrated in Figures 1 to 3, the invention relates to an electric heating device. It is, for example, a heating device, called high voltage, that is to say intended to be supplied by a direct current (DC) or alternating current (AC) having an electrical voltage greater than 60 V , in particular between 60 and 1000 V, more particularly between 180 and 600 V, and / or allowing a heating power to be released on the air or a consumed electric power greater than 2 kW, in particular between 2 kW and 10 kW .

Said heating device comprises a heating body 10 supplied with electric current to heat a flow of air passing through said heating body 10.

Said heating body 10 here has a substantially parallelepiped configuration, extending on the surface. It is intended to be positioned transversely to the air flow to be heated. More specifically, said air flow is intended to be oriented perpendicular to said heating body 10, that is to say perpendicular to the plane of the figures, for Figures 1 to 3

The heating body 10 comprises heating elements 11 (visible in FIG. 6) traversed by said current. The heating elements 11 are, for example, PTC effect resistors (for positive temperature coefficient).

The said heating element (s) 11 are located inside one or more housings 12 of the said heating body 10 to electrically isolate the said heating element (s) 11 from the outside,

The housings 12 form with the heating elements 11 heating units 8. Said heating units 8 are selectively supplied with current. By this is meant that each heating unit 8 is supplied with current independently of the others and can therefore be traversed by a different current, in particular by its intensity, from the current flowing through the other heating units 8. The value of the current in play here is in particular the value of the average current or the effective current.

As can be seen more clearly in FIG. 4, the housings 12 are respectively formed of tubes 13.

The heating units 8 also comprises an electrode 15, located on either side of the heating elements 11 for their supply of electric current. Said heating units 8 also comprise layers of material 17, electrically insulating and thermally conductive, said layers being located between one of the electrodes and a wall of the tube 13. In this way, the tube 13 is electrically insulated from the electrodes 15 and heating elements 11.

Preferably, said heating elements 11 are electrically connected in parallel, in particular using the electrodes 15. Said heating elements are advantageously distributed regularly along the housings 12.

If we refer to Figures 1 to 3, we see that said heating body 10 may also include heat sinks 18, for example fins, in thermal contact with the tubes 13. The heatsinks 18 are positioned, in particular , between said tubes 13.

Said heating body comprises a frame 14, in particular made of plastic, accommodating said heating units 8 and serving to hold said housings 12. Said frame comprises two opposite lateral uprights 3, 4 as well as a proximal upright 5 and a distal edge 6 opposite, said proximal edge 5 and said distal edge 6 joining the lateral edges 3, 4 for example by their ends. The said tube (s) 13 open out through a first of their longitudinal end facing the proximal upright 5 and / or through a second of their second longitudinal end facing the distal upright 6. In FIG. 3, said frame 14 has not been shown and only the heating units 8 and the heatsinks 18 are visible.

Preferably, the heating device further comprises a unit 20 for distributing and / or controlling the current flowing in said heating body 10.

Said heating and / or control unit is advantageously configured to control the current supplying the heating body 10, in particular the various heating units 8, for example using piloted switches, making it possible to respectively control a flow of current in each of the heating units 8. These are, in particular, transistors, for example of the Mosfet or IGBT type, operating in particular by pulse width modulation.

Said distribution and / or control unit 20 comprises a housing 22. Said housing 22 comprises a connection face 24, used for mounting and / or for mechanical fixing of the heating body 10, in particular by the lateral uprights 3, 4 of said frame 14. In the first embodiment, corresponding to that illustrated in FIG. 1, said housing 22 is located along the proximal edge 5 of the frame 14. In other words, said proximal upright 5 is located opposite said unit distribution and / or control, 20. In the second embodiment, corresponding to that illustrated in FIG. 2, the frame 14 does not have a proximal edge 5 and the first end of the tubes 13 is directly opposite connection face screw

24.

Preferably, the electrodes 15 comprise ends 25 opening into the housing 22. Said ends 25 are configured to form male connectors cooperating with female connectors, not shown, located in the housing 22.

As is more particularly illustrated in FIGS. 1 and 2, said device comprises a support, ensuring at least partial closure of said housing (s) 12. It further comprises one or more seals 30, 30 ′ attached to said support to ensure sealing of the closure of the housing or housings 12. In FIGS. 1 and 2, the seals 30, 30 ′ are illustrated in transparency in order to visualize their positioning.

In other words, the seals 30, 30 ′ are previously fixed on their support, this before mounting the heating body 10 or before assembling the heating body 10 on the distribution and / or control unit 20. Such prepositioning promotes the good positioning and speed of assembly of the seals 30, 30 '.

In other words, according to the various embodiments illustrated, the said tube or tubes 13 are closed in leaktight manner at least at one of their longitudinal ends by said support with the help of one of said seals 30, 30 ’. Said seals 30, 30 ’are arranged between the longitudinal end of the tubes 13 and the support located opposite. They are advantageously compressed between an end edge of the walls of the tubes 13 and the corresponding support.

More specifically, in the embodiment of FIG. 1, at least one of the seals, known as the first seal 30, is located on said heating body 10, in particular on its proximal upright 5. Said heating body 10 forms so a first part of the support, said first part of the support closing the first longitudinal end of said tubes 13.

As a variant, in the embodiment of FIG. 2, the first seal 30 is fixed to the current distribution and / or control unit 20, in particular the connection face 24 of its housing 22. Said distribution unit and / or control 20 thus form a first part of the support, said first part of the support closing the first longitudinal end of said tubes 13.

Said first part of the support, in other words the proximal upright 5 of the frame 14 and / or the connection face 24 of the housing 22, includes orifices for passage of the supply electrodes 15 of the heating elements 11. Preferably, a cross section of passage of the orifices for passage of the supply electrodes of the proximal upright 5 is identical to a cross section of the orifices for passage of the supply electrodes of the connection face 24.

As illustrated in FIGS. 5a to 5c, said first seal 30 comprises openings 32 for the passage of the supply electrodes. The apertures 32 of the first seal are located opposite said passage orifices 34 of the supply electrodes. Here, for the sake of simplification, only the component serving as support for the first seal 30 has been illustrated, whether it is the proximal upright 5 of the frame 14, as in the first embodiment of FIG. 1, or the connection face 24 of the housing 22 as in the second embodiment of FIG. 2.

In FIG. 5a, said slots 32 have a constant cross section along a thickness of the joint 30.

In FIG. 5b, said slots 32 have a decreasing cross section in the direction of the orifices 34 for the passage of the electrodes, provided in the proximal upright 5 of the frame 14 and / or the connection face 24 of the housing 22.

In FIG. 5c, said slots 32 have a growing cross section in the direction of the orifices 34 for the passage of the electrodes provided in the proximal upright 5 of the frame 14 and / or the connection face 24 of the housing 22.

In these different figures, a cross section of the lumens 32 at one face of the first seal 30 facing said passage orifices 34 is identical to that of the passage orifices 34. As a variant, it may be smaller or larger.

In general, such a comparison of said cross sections is carried out before assembly, the compression of the joint taking place during assembly being liable to deform it.

Alternatively, not shown, the first seal 30 is full and the slots 32 are formed by drilling the first seal 30 by the electrodes 15 during assembly.

As illustrated in FIG. 6, the first seal 30 extends between said orifices for passage of the supply electrodes 15.

As illustrated in FIG. 7, as a variant, said first seal 30 is formed of first unitary seals 30i, ..., 30 _n independently attached to said support, that is to say here either the proximal upright 5 of the frame 14 , or the connection face 24 of the housing 22. Each of said first unitary seals is situated opposite one of said housings, namely here facing the first longitudinal end of said tubes 13. The first seals unit 301, ..., 30n are preferably of annular shape to match the contour of the tubes 13.

In this regard, it is understood that the relative positioning of the electrodes 15 in the frame 14 and of the orifices 34 for the passage of the electrodes 15 of the connection face 24 cause the relative positioning of the first seals 30 relative to the first end of the tubes 13 without that it is necessary to ensure individually such positioning, tube by tube, this is a case of a seal extending between said orifices 34 of passage or a seal formed of unitary seals. Indeed, in each case, the seal will have been prepositioned on its support.

If we refer again to Figures 1 and 2, we see that at least one 30 'of the joints, said second seal, is located on said frame 14, in particular on its distal amount 6, said distal amount 6 of the frame 14 thereby forming a second part of said support. Said second part of the support, in other words said distal edge 6 closes the second longitudinal end of said tubes 13.

According to a first variant, said second seal 30 ′ extends continuously over said distal upright 6. Such a configuration is to be compared to that of FIG. 6 for the first seal 30.

As a variant, said second seal 30 ′ is formed of second unitary seals independently attached to said distal upright 6. Each of said second unitary seals is located opposite one of said housings, namely here the second longitudinal end tubes 13. The second unitary seals preferably having the form of discs whose perimeter follows the outline of the tubes 13. Such a configuration is to be compared to that of FIG. 7 for the first seal 30.

Referring again to Figure 3, we see that the positioning of the first and second seals 30, 30 'relative to the first and second longitudinal ends of the tubes 13 is illustrated in dotted lines, such positioning being common to the two embodiments illustrated in FIGS. 1 and 2, that is to say that the first seal is attached to the distal upright 5 of the frame 14 or to the connection face 24 of the housing 22.

For example, said joint (s) 30, 30 ’are formed with the support by overmolding and / or by bi-injection. Alternatively, said joint or joints 30, 30 ’are fixed to said support by gluing and / or mechanical attachment.

The said joint (s) 30, 30 ′ are, in particular, made of elastomeric material, silicone and / or foam.

In order to allow good compression of said joint (s) 30, 30 'against the support (s), said frame 14, in particular its proximal upright 5 and / or its distal upright 6, as well as the housing 22, in particular its connection face 24, have a high rigidity, at least higher than that of the joint (s) 30, 30 '. For example, they are made of plastic materials such as PBT or PA. For the same purpose, said proximal post 5, said distal post 6 and / or said connection face 24 have an intrinsic bend, straightened during assembly.

Said device may also comprise means for fixing the heating body 10 allowing compression of the joint (s) 30, 30 ‘on their support. It may be, in particular a snap fastening.

The invention also relates to an air conditioning unit comprising a heating device as described above. Said housing comprises a body for circulating the air flow inside which said heating device is located.

Claims (20)

1. A heating device for an air conditioning unit, said heating device comprising a heating body (10) supplied with current for heating an air flow passing through said heating body (10), the heating body (10) comprising a or heating elements (11), traversed by said current, said heating element (s) (11) being located inside one or more housings (12) of said heating body (10) to electrically isolate the or said heating elements (11) from the outside, said device comprising a support, ensuring at least partial closure of said housing (s) (12), and one or more seals (30, 30 ') attached to said support to ensure sealing of the closure of the housing (s) (12). 2. Device according to claim 1 in which the said housing (s) (12) are respectively formed of a tube or tubes (13), the said tube (s) (13) being sealed in at least one of their longitudinal ends by said support with the help of one of said seals (30, 30 '). 3. Device according to claim 2 comprising a unit (20) for distributing and / or controlling the current flowing in said heating body. 4. Device according to claim 3 in which at least one of the seals, said first seal (30) is located: - heating element side (10), and / or - side (20) of current distribution and / or control unit, said heating body (10) and / or said unit (20) of distribution and / or control thus forming a first part of the support, said first part of the support closing a first longitudinal end of said tubes (13). 5. Device according to claim 4 wherein said heating body (10) comprises a frame (14) for holding said housings (12), said frame (14) being provided with an upright (5), called proximal, located in with respect to said distribution and / or control unit (20), said first seal (30) being attached to said proximal upright (5). 6. Device according to claim 4 wherein said distribution and / or control unit (20) comprises a housing (22) provided with a connection face (24) to the heating body (10), said first seal (30 ) being attached to said connection face (24). 7. Device according to any one of claims 4 to 6 wherein said first part of the support comprises orifices (34) for passage of feed electrodes (15) of the heating elements (11). 8. Device according to claim 7 wherein said first seal (30) comprises slots (32) for passage of the supply electrodes (15). 9. Device according to claim 8 wherein said slots (32) have a constant cross section along a thickness of the joint (30). 10. Device according to claim 8 wherein said slots (32) have a decreasing cross section in the direction of the orifices (34) for the passage of the electrodes (15). 11. Device according to claim 8 wherein said slots (32) have a cross section increasing in the direction of the orifices (34) for the passage of the electrodes (15). 12. Device according to any one of claims 8 to 11 wherein said slots (32) have a cross section substantially identical to that of the orifices (34) for passage of the supply electrodes (15). 13. Device according to any one of claims 7 to 12 wherein said first seal (30) extends between said orifices (34) for passage of the supply electrodes (15). 14. Device according to claim 4 wherein said heating body (10) comprises a frame (14) for holding said housings (12), at least one of the seals, said second seal (30 '), being located on said frame (14), said frame thereby forming a second part of said support, said second part of the support closing a second longitudinal end of said tubes (13). 15. Device in which said frame (14) comprises an upright, said to be distal (6), opposite which opens said tube (s) (13) by their second longitudinal end, said second seal (30 ') being located at said distal post (6). 16. Device according to claim 15 wherein said second seal (30 ’) extends continuously over said distal post. 17. Device according to any one of the preceding claims, in which said seal (30, 30 ') is formed with the support by overmolding and / or by bi-injection and / or said seal (30, 30') is fixed to said support by gluing and / or mechanical attachment. 18. Device according to any one of the preceding claims 5, in which said seal is made of elastomeric material, silicone and / or foam. 19. Device according to any one of the preceding claims comprising means for fixing the heating body allowing a 10 compression of the joint (s) (30, 30 ’) on their support. 20. Air conditioning unit comprising a heating device according to any one of the preceding claims.