Patent Document

BACKGROUND OF THE INVENTION 
     The invention concerns a device for fixing a first heat exchanger conduit on a second heat exchanger fluid reservoir, in particular for a motor vehicle. 
     Devices of this sort are already known, which are used, for example, for fixing an air conditioning condenser conduit on a motor vehicle engine cooling radiator fluid reservoir. 
     In such an application, the two heat exchangers are disposed in proximity to one another, so that one and the same air flow successively passes across the condenser body and the radiator body. 
     The condenser has passing through it a cooling or refrigerating fluid which enters in the vapour phase and emerges therefrom in the liquid phase after condensation by exchanging heat with the air flow. 
     In addition, the cooling radiator has passing through it a liquid used for cooling the engine, this liquid entering the radiator at high temperature and emerging therefrom at a lower temperature, after exchanging heat with the air flow. 
     Usually, the condenser is fixed on the cooling radiator, for example by appropriate fittings formed on the fluid reservoirs situated at the two ends of the radiator body. 
     The condenser has two conduits used respectively for the introduction and the evacuation of the cooling fluid. 
     Generally, provision is made to fix-at least one of these conduits on a fluid reservoir of the radiator by appropriate fixing means. 
     Until now this fixing has been accomplished with collars which are placed around the conduit and then fixed to the fluid reservoir by means of a screw which passes through the collar and engages in a blind hole made in a wall of the fluid reservoir. 
     However, this solution is not satisfactory since it requires a number of operations which are tricky and difficult to implement, notably on automated motor vehicle assembly lines. 
     Moreover there is always a risk of a collar being lost during assembly operations. 
     BRIEF SUMMARY OF THE INVENTION 
     The aim of the invention is notably to overcome the aforementioned drawbacks. 
     To that end, the invention proposes a fixing device, which has at least one fixing bracket formed integral with one of the conduit and the fluid reservoir and suitable for being fixed in a detachable manner on the other of the conduit and the fluid reservoir. 
     Thus, instead of using a collar added subsequently on to the fluid reservoir, at least one fixing bracket already formed integral with the conduit or with the fluid reservoir is utilized. 
     This results in not only a simplified assembly, but also eliminates any risk of loss of the fixing bracket. 
     In a first embodiment of the invention, the fixing bracket is moulded in one single piece with a wall of the fluid reservoir. This fixing bracket has an open part suitable for receiving the conduit. 
     Thus, assembly is simply accomplished by inserting the conduit into the open part of the fixing bracket. This fixing is performed quickly, without requiring any special tools. 
     Preferably, the open part of the fixing bracket has substantially a ‘C’ shape in order to allow force fitting of the conduit. 
     As a result, the this open part exerts a clamping action on the conduit, preventing it leaving the housing defined in the open part of the fixing bracket. 
     Advantageously, the open part of the fixing bracket has substantially the form of a cylindrical sleeve having a longitudinal opening. 
     The open part of the fixing bracket is advantageously connected to the wall of the fluid reservoir by two spaced wings. 
     This configuration allows easy moulding and removal from the mould by appropriate moulding techniques. 
     According to another characteristic of the invention, the fixing bracket is attached to a prominent region of the wall. 
     Advantageously, the fluid reservoir and the fixing bracket are moulded in one single piece from a thermoplastic material. 
     In another embodiment of the invention, the fixing bracket is welded to the conduit and may be fixed to a wall of the fluid reservoir by means of a fixing screw. 
     Thus the fixing of the bracket is performed simply with the help of a screw, with no risk of loss of the bracket on account of the bracket being integral with the conduit. 
     According to an advantageous characteristic of the invention, the fixing bracket has a first end welded to the conduit and a second end provided with a hole for the fixing screw to pass through. 
     Preferably, the first end has substantially a C shape adapted to the shape of the conduit and the second end is a continuation laterally of the C-shaped part. 
     The wall of the fluid reservoir is advantageously provided with a blind hole for receiving the fixing screw. 
     Advantageously, the wall forms part of a projection of the fluid reservoir. 
     In a preferential application of the invention, the conduit is intended to have a cooling fluid passing through it. 
     Thus, the first heat exchanger may be a condenser forming part of an air conditioning system, and the second heat exchanger a cooling radiator for an engine, in particular of a motor vehicle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following description, given solely by way of an example, reference is made to the accompanying drawings, in which: 
     FIG. 1 is a schematic top view of a fixing device according to the invention, applied to the fixing of a condenser conduit on a fluid reservoir of a cooling radiator; 
     FIG. 2 is a partial side view of a fluid reservoir and a fixing device according to a first embodiment of the invention, before installation of the conduit; 
     FIG. 3 is a partial perspective view of the fluid reservoir equipped with the fixing device of FIG.  2  and used for holding a conduit; and 
     FIG. 4 is a partial elevational view of a fluid reservoir equipped with a fixing device according to a second embodiment of the invention and used for holding a conduit. 
     FIG. 5 is a partial side view of a conduit and a fixing device according to a third embodiment of the invention, installed on a fluid resevoir. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is made first to FIG. 1 which depicts a condenser  10  suitable for forming part of an air conditioning system (not depicted) of a motor vehicle. The condenser  10  has a body  12  to which are connected two conduits  14  and  16  used respectively for the admission and the evacuation of a cooling fluid, as represented respectively by the arrows F 1  and F 2 . 
     The condenser  10  is disposed in proximity to a radiator  18  used for cooling the engine of the motor vehicle. This radiator has a body  20  which is disposed parallel to and facing the body  12  of the condenser  10 . As a result, a single air flow, as represented by the arrows A, can successively pass across the body  12  of the condenser  10  and the body  20  of the radiator  18 . 
     The radiator  18  has two fluid reservoirs  22 ,  24 , also referred to as “collecting reservoirs”, provided respectively with two pipes  26 ,  28  used respectively for the admission and the evacuation of a cooling fluid, as represented by the arrows F 3  and F 4 . This cooling fluid is usually a cooling liquid which passes through the engine of the motor vehicle. 
     The fluid reservoirs  22  and  24  have appropriate fittings (not depicted) to allow the fixing of the condenser  10 , in a manner known to those skilled in the art of the invention. 
     The conduit  14  is fixed to the collecting reservoir  22  by a fixing bracket  30  which will be described more particularly with reference to FIGS. 2 and 3. 
     The fixing bracket  30  is moulded in a single piece at a prominent region of a wall  32  of the fluid reservoir  22 . The fluid reservoir and the fixing bracket are advantageously moulded in a single piece from a thermoplastic material, in particular from a polypropylene type material. 
     The fixing bracket  30  comprises an open part  34  which has, in transverse section, substantially a ‘C’ shape (FIG. 2) in order to allow force fitting of the conduit  14 . This open part  34  has a longitudinal opening  36  whose width L (FIG. 2) is slightly less than the external diameter of the conduit  14 . As a result insertion of the conduit  14  into the open part  34  is performed with deformation of the latter in order to allow widening of the opening  36 . Then, when the conduit has been completely inserted, the opening  36  narrows again, which allows the conduit to be held inside the open part  34 . 
     The open part  34  has substantially the form of a cylindrical sleeve in which the longitudinal opening  36  is made. 
     In the example depicted, the open part  34  is connected to the wall  32  of the fluid reservoir by two spaced wings  38  (FIG.  3 ). This configuration can be easily obtained by moulding or use of appropriate broaching tools. 
     The other conduit  16  of the condenser  10  is fixed to the fluid reservoir  24  by a fixing bracket  30  analogous to the preceding one, moulded in a single piece with the fluid reservoir  24 . Of course, the conduits  14  and  16  could be situated on a single side of the condenser  10  and be fixed on the same fluid reservoir, for example the fluid reservoir  22 , by means of two fixing brackets  30  attached to the same wall of the fluid reservoir. 
     As can be seen in FIG. 3, the conduit  14  ends at a connection block  40 , which enables connection of the conduit  14  with other parts of the air conditioning system. 
     In the embodiment of FIG. 1, fixing bracket  30  is moulded in a single piece to conduit  14 . The fixing bracket include a substantially C-shaped open part  34  in order to allow force fitting of a region  32  of the fluid reservoir  22 . The open portion of the fixing bracket is joined to the conduit by spaced wings  38 . 
     In the embodiment of FIG. 4, the fixing bracket  40  is welded to the conduit  14  and is fixed in a detachable manner on a fluid reservoir  42  by means of a fixing screw  44 . 
     The fixing bracket  40  has an end  46  having substantially a C shape adapted to the shape of the conduit  14  in order to serve as a housing for the conduit. The end  46  and the conduit  14  are made integral with one another by welding or brazing and thus form an indissociable assembly avoiding any risk of loss of the fixing bracket. The fixing bracket and the conduit are advantageously both formed from a metallic material such as aluminium or an aluminium-based alloy. 
     The end  46  is extended laterally by an end  48  of generally flat form, which is provided with a hole  50  for the fixing screw  44  to pass through. 
     This screw has a head  52  coming to rest against the fixing bracket  40  and a threaded part  54  engaging in a blind hole  56  made in the fluid reservoir  42 . The blind hole  56  is formed in a wall  58  forming part of a projection  60  of the fluid reservoir  42 , situated close to a pipe  62  of the fluid resevoir. 
     Although the invention described in various illustrative embodiments, the invention intended to be is not limited to the embodiments described previously by way of examples and extends to other variants apparent to those skilled in the art in view of the foregoing description. 
     As already indicated, it would be possible to provide two fixing brackets in order to fix two conduits of a heat exchanger on the same fluid reservoir. 
     Furthermore, although the invention has been described with particular reference to fixing a condenser conduit on a cooling radiator fluid reservoir, it can be applied to other types of heat exchanger. 
     Thus this technique could be applied where the heat exchangers comprise a cooling radiator and a turbocharger air radiator.

Technology Category: 2