Abstract:
The invention concerns an air conditioning condenser for a motor vehicle passenger compartment comprising a reservoir mounted on a base. The reservoir is axially screwed in the base, itself soldered on a manifold box of the condenser, communicating therewith through ducts arranged in the base. The base further comprises a mounting pin for helping to fix the condenser on the support, and/or a linking duct for connecting the condenser to the rest of the refrigerating circuit.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a condenser capable of forming part of a fluid circuit, in particular for refrigerating fluid, in an air conditioning device of the passenger compartment of a motor vehicle. The condenser comprises a manifold box and an elongated intermediate reservoir for the treatment and/or the accumulation of the fluid, two communicating pipes being provided for the transfer of liquid between the manifold box with and the reservoir. 
     In such a condenser, as is well known, the intermediate reservoir may perform all or part of the following functions: filtration and/or dehydration of the refrigerating fluid, compensation of the variations in volume of the fluid, separation of the liquid and gaseous phases. Its intermediate position, i.e. its interposition between an upstream section and a downstream section of the condenser, allows only fluid in the liquid state to be circulated in the section upstream from the reservoir. The fluid is thus undercooled to the liquid/gas equilibrium temperature, improving the performances of the condenser and making the condenser relatively independent of the quantity of fluid contained in the circuit. 
     EP-A-0 480 330 describes, in a vehicle air-conditioning condenser, an intermediate circuit which is removably fixed to a base integral with the manifold box, through which the two communicating pipes pass. 
     The object of the invention is to simplify the mounting of the condenser, by making the base at least play a supplementary role with respect to the fluid and mechanical communications. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention in particular relates to a condenser of the type defined in the background, and specifies that the base comprises means for fixing the condenser and/or for establishing a fluidic communication between said condenser and the remainder of the circuit. 
     Complementary or alternative optional characteristics of the invention are given below: 
     The means for establishing fluidic communication comprise a connecting pipe passing right through the base. 
     The connecting pipe communicates directly by a first of its ends with the manifold box. 
     The second end of the connecting pipe forms the outlet of the condenser. 
     The first end of the connecting pipe is substantially aligned with the respective ends of the communicating pipes which communicate with the manifold box, in the longitudinal direction of the latter. 
     The communicating pipe communicates with the manifold box in the vicinity of the lower end thereof. 
     The means for fixing the condenser comprise a mounting pin suitable for being inserted into a connected cavity to contribute to the attachment of the condenser to a support. 
     The mounting pin is turned away from the reservoir in relation to the base. 
     The mounting pin is turned towards the bottom of the condenser. 
     The mounting pin is disposed substantially along an axis parallel to that of the reservoir. 
     The condenser comprises a bank of tubes that are parallel to one another and perpendicular to the longitudinal direction of the manifold box, each of which communicates with the manifold box at one of its ends, the bank of tubes bearing a second mounting pin offset in relation to that of the base in the longitudinal direction of the tubes. 
     The reservoir is equipped in the vicinity of a first of its ends with an axial thread which cooperates for attachment with the base, the communicating pipes extending therein until opposite the first end. 
     The reservoir has an axial pipe fitting for the passage of fluid which projects at its first end in order to be connected in the interior of the base to one of the communicating pipes. 
     The reservoir has at its first end apertures for the passage of fluid surrounding the axial pipe fitting and communication with the second of the said communicating pipes. 
     The first pipe extends substantially perpendicularly to the longitudinal direction of the reservoir. 
     The second pipe is oblique in relation to the longitudinal direction of the reservoir, and deviates from the first pipe in the direction of the manifold box. 
     The first and the second pipes are disposed respectively downstream and upstream from the reservoir. 
     The base is soldered onto the outer face of a tubular wall delimiting the manifold box. 
     The communicating pipes extend substantially tangentially in relation to the said tubular wall and open laterally through said wall. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The characteristics and advantages of the invention will be exhibited in further detail in the following description, with reference to the attached drawings, in which identical or similar elements are designated in all the figures by reference numbers. On these drawings: 
     FIGS. 1,  2  and  3  are front, side and top views of a condenser according to the invention, 
     FIG. 4 is a circuit diagram of a refrigerating fluid circuit incorporating the condenser; 
     FIG. 5 is an axial sectional view of the reservoir; 
     FIGS. 6 to  8  are front views of the base, 
     FIGS. 9 and 10 are perspective views of the base; 
     FIG. 11 is a top view of the base; 
     FIGS. 12,  13  and  14  are views similar to FIGS. 1 to  3 , in relation to a second embodiment of the condenser; 
     FIGS. 15 and 16 are front views of the base in the second embodiment; 
     FIGS. 17 and 18 are perspective views of the base; and 
     FIG. 19 is a top view of the base. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 4 is a circuit diagram of a refrigerating fluid circuit which forms part of an air-conditioning unit for the passenger compartment of a motor vehicle. In known manner, this circuit successively comprises a compressor  1 , a unit  2  hereinafter designated under the name of condenser, an expansion valve  8  and an evaporator  4 . The condenser  2  comprises an upstream section  2   a  in which the refrigerating fluid gives up heat to a flow of air so as to condense, after having been, if necessary, “de-overheated” from a inlet temperature greater than the liquid/gas equilibrium temperature. Section  2   a  is followed by an intermediate reservoir  2   b,  then by a downstream section  2   c  in which the fluid is undercooled by heat exchange with the flow of air. 
     An exemplified embodiment of the condenser  2  is shown in its general structure on FIGS. 1 to  3 . It comprises two manifold boxes  3 ,  4  that are extended vertically and separated from one another in a horizontal direction, and interconnected by a multiplicity of horizontal fluid circulation tubes  5 . Each manifold box is divided into different chambers by horizontal partitions  6  so that the fluid circulates, in the tubes  5 , alternately from a chamber of the box  3  to a chamber of the box  4 , and vice versa, from the upper chamber of the box  4 , which communicates with an inlet pipe fitting  7 , to the lower chamber of the box  3 . 
     One of the intermediate partitions of the manifold box  3 , designated by reference  6 - 1 , separates chambers  9 - 1  and  9 - 2  from one another, which are situated respectively above and below the partition  6 - 1 . The chambers communicate between themselves exclusively by means of the reservoir  2   b,  which is extended vertically and extends along the box  3 . The chamber  9 - 2  is in turn separated from the lower chamber of the box, designated by the reference  9 - 3 , by a partition  6 - 2 . 
     As can be seen more particularly on FIG. 5, the reservoir  2   b  comprises a housing formed of a cylindrical body  11  occupying the greater part of its height, and a narrowed neck  12  disposed at its lower part. The neck  12  in turn has a region  13  equipped with an external thread and, beneath this threaded region, a region  14  having a smaller diameter, bored by circumferential grooves for housing two O-ring seals  15 . At its lower end, the reservoir  2   b  has a transversal end wall  16  through which firstly an axial pipe fitting  17  passes, and protrudes upwardly inside the reservoir and downwardly outside said reservoir. Secondly, the transversal end wall has apertures  18  surrounding the pipe fitting  17 . The pipe fitting  17  extends upwards to a perforated intermediate partition  19 , which the pipe fitting passes through before opening into a free volume  20  contained between the partition  19  and the closed upper end of the reservoir. The pipe fitting extends over the major part of the height thereof. Two washers  21 ,  22  permeable to fluid surrounding the pipe fitting  17  and resting respectively upwardly on the partition  19  and downwardly on a shoulder connecting the regions  13  and  14 , delimit between them an annular treatment volume  23  capable of filtering and/or dehydrating the fluid. 
     The reservoir  2   b  is in mechanical and fluidic communication with the manifold box  3  by means of a base  30  which is represented in detail on FIGS. 6 to  11 . This base is preferably moulded from an aluminium alloy, and defines a wall  31  substantially generated by rotation around a vertical axis  32 , which delimits a receptacle  33  open upwardly for the neck of the reservoir  2   b.  The lateral surface of the receptacle  33  has, in an upper region, a internal thread  34  cooperating with the thread  13  of the reservoir, in such a manner that the thread of the reservoir also has axis  32  as its axis. A cylindrical median region  35  cooperates with the O-ring seal  15 , and a lower cylindrical region  36  surrounds the pipe fitting  17  and delimits an annular space with said fitting, whose free end rests on a seat  37  provided at the bottom of the receptacle  33 . 
     Externally connected to the wall  31  is a shell  39  extending substantially along a plane passing through the axis  32 . The shell has, on both sides of this plane, swellings  40  which enable two pipes  41 ,  42  that are extended parallel to this plane to be housed. In an intermediate production stage of the base, the pipe  41  extends from the free edge of the shell  39  at an angle to horizontal pipe  42  and opens in the receptacle  33 , at the level of the above mentioned annular space. The pipe  42  extends horizontally from the free edge of the shell to beneath the receptacle  33 , where the pipe  42  forms an elbow upwardly to open at the bottom of said shoulder into the annular seat  37 . In the finished base, soldered plugs (not represented) blank off in a tight manner the free ends of the pipes  41 ,  42  and said pipes open on the outside exclusively by passages  45 ,  46  provided in the lateral projections  47 ,  48  formed on the swellings  40 . 
     A projection  50  formed at the lower end of the shell  39  extends on both sides of the plane of said shell. A pipe  51  passes through the projection  50 . The projections  47 ,  48 ,  50  form, around the ends of the passages  45  and  46  and of the pipe  51  turned towards the manifold box  3 , cylindrical tubular end fittings  52 ,  53 ,  54 , which are mutually aligned with respect to the direction of the axis  32 . 
     The base  30  is fixed on the manifold box  3  by soldering projections  47 ,  48 ,  50  on the outer face of the tubular wall of the manifold box, at lest partly made of aluminum sheet, upon the assembly of the condenser. The passages  45  and  46  and the pipe  51  communicate with the chambers  9 - 1 ,  9 - 2  and  9 - 3  respectively of the box by holes provided in the tubular wall. The end fittings  52  to  54  engage in these holes. 
     The fluid penetrating through the tube fitting  7  into the upper chamber of the manifold box  4  passes through a first group of tubes as shown by arrow F 1  to reach the upper chamber of the box  3 , then through two other groups of tubes, as shown by arrows F 2  and F 3 , to pass into the intermediate chamber of the box  4  and into chamber  9 - 1  of the box  3 . The condensed fluid thus arriving in the chamber  9 - 1  passes therefrom into the annular space in the base by the passage  45  and the inclined pipe  41 , then penetrates into the reservoir  2   b,  which is screwed into the base, via the apertures  18 . The fluid then passes through the volume  23  where it is dehydrated and filtered by the particles  24 , and accumulates in the volume  20 , where the possible residual gaseous phase collects at the upper part. The fluid leaves the volume  20 , exclusively in the liquid state, by the tube fitting  17 , and reaches the chamber  92  of the manifold box  4  by the horizontal pipe  42  and the passage  46 . Thus, the tubes  5  and the chambers of the boxes  3  and  4  situated higher than the partition  6 - 1 , including the chamber  9 - 1 , form the upstream section  2   a  of the condenser, whereas the tubes and the chambers situated lower than this partition, including the chamber  9 - 2 , form the downstream section  2   c.  The fluid passes from the chamber  9 - 2  to the lower chamber of the manifold box  4  as shown by the arrow F 4 , then is directed towards the chamber according to the arrow F 5 . The fluid leaves the latter chamber, and the condenser, by the pipe  51 , the projection  50  playing the role of outlet pipe and thus replacing an additional connected tube fitting. 
     A retention flange  55  mechanically connects the upper end of the reservoir  2   b  to that of the manifold box  3  for a more stable attachment of the reservoir. 
     The condenser of FIGS. 12 to  14  has the same general constitution as that described hitherto, from which it differs slightly by known characteristics, without relation with the invention, which will not be described in detail. It also differs therefrom by its base, which is represented in detail on FIGS. 15 to  19 . This base  30  is identical to that described above with respect to its cooperation with the reservoir  2   b  and the communication between said reservoir and the chambers of the manifold box  3 . It differs therefrom essentially by the absence of the projection  50  and of the pipe  51 , and by the presence of a mounting pin  60 . The pin  60  is similar to a mounting pin  61  which forms part of an independent piece  62  fixed to the lower edge of the tube bundle  5 , in the vicinity of the manifold box  4 . Like the pin  61 , the pin  60  projects downwardly, along a vertical axis, from a horizontal disk  63 , its section being less/lower than the surface of the disk and becoming smaller towards its lower end. In the illustrated example, the axis of the pin  60  is offset in relation to the axis  32  of the reservoir in the direction of the median plane of the tube bundle  5 . The disk  63  is disposed perpendicular to the plane of and at the lower end of a cross piece formed by the shell  39  and a rib  64  extending on both sides thereof. The pins  60  and  61  are intended to engage in connected cavities of a support, belonging for example to the automotive body or to the chassis of a vehicle, and contribute to the attachment of the condenser  2 . The presence of the pin  60  avoids having to fix a second piece similar to piece  62  onto the bank of tubes in the vicinity of the manifold box  3  as usual in conventional practice. 
     Of course, the base of the condenser according to the invention may comprise attachment means and/or fluidic communication means which are different from those described by way of example. Similarly, attachment means and communication means may be combined on a single base.