Abstract:
The invention relates to a device ( 28 ) for coupling a heat exchanger, such as an evaporator ( 10 ), to an expansion valve ( 26 ), in particular for a vehicle, said exchanger and said expansion valve being provided with ports ( 18, 20, 22, 24 ) for the inlet/outlet of fluid, at least one ( 24 ) of the ports of the expansion valve not being aligned with one ( 18 ) of the ports of the exchanger, said device including a first part ( 30 ), intended for being assembled and seemed to the exchanger and/or the evaporator, said first part ( 30 ) being capable of defining, with at least one adjacent part, at least one first fluid passage intended for connecting said non-aligned ports ( 18, 24 ), said adjacent part being selected among a second part ( 32 ) of said device, said exchanger and/or said expansion valve.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a device for coupling a heat exchanger such as an evaporator to an expansion valve, in particular for a vehicle. 
       STATE OF THE ART 
       [0002]    An evaporator is known, intended for an air conditioning device of the interior of a vehicle, that comprises a bundle formed from a stack of plates allowing for a heat exchange between a flow of air passing through the bundle and a refrigerant circulating in the bundle. The bundle is arranged between two end plates. This type of evaporator is described in the document FR-A1-2 026 437 from the applicant and is well known to those skilled in the art. 
         [0003]    One of the end plates of the evaporator comprises two ports respectively for the refrigerant to enter into the evaporator and for this fluid to exit. 
         [0004]    It is also known practice to link the evaporator to an expansion valve via a coupling device which is generally formed by a metal block. The expansion valve comprises fluid inlet and outlet ports intended to be linked by internal passages of the coupling device respectively to outlet and inlet ports of the evaporator. The axes of the inlet and outlet ports of the expansion valve are parallel and extend in a plane passing substantially through a bulb of the expansion valve. 
         [0005]    In use the bundle of he evaporator is generally arranged vertically and the inlet and outlet ports of the evaporator then emerge horizontally. 
         [0006]    In the case where the expansion valve is positioned horizontally and the center distance of the ports of the evaporator is substantially identical to that of the ports of the expansion valve, that does not pose any design problems regarding the coupling device because its internal fluid passages can be rectilinear, which is relatively simple to produce. The document EPA2-1 515 104 describes a coupling of this type. 
         [0007]    However, to optimize the operation of the bulb of the expansion valve, it is preferable for it to be in a high position, which means positioning the expansion valve such that the abovementioned plane of its ports is in a vertical position or slightly inclined relative to the vertical. This nevertheless poses a design problem regarding the coupling device. In effect, although one of the passages of the device could be substantially rectilinear to couple aligned ports of the evaporator and of the expansion valve, the other passage is more complex to produce because it has to include one orifice aligned with the port of the evaporator, another orifice aligned with the port of the expansion valve, and a duct linking these orifices. A first solution for producing this duct would be to orient it in an inclined manner and to produce it by drilling into the body inside the block of the device during a machining operation. This would however be complex to implement and would entail overdimensioning the block because or the bends to be formed. 
         [0008]    The aim of the present invention is notably to provide a simple, effective and economical solution to this problem. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention proposes a device for coupling a heat exchanger, such as an evaporator, to an expansion valve, in particular for a vehicle, said exchanger and said expansion valve being provided with fluid inlet/outlet ports, at least one of the ports of the expansion valve not being aligned with one of the ports of the exchanger, said device comprising a first part, intended to be joined and fixed to the exchanger and/or the evaporator, said first part being suitable for defining, with at least one neighboring part, a first fluid passage intended to couple said non-aligned ports, said neighboring part being chosen from second part of said device, said exchanger and/or said expansion valve. 
         [0010]    The invention makes it possible to simplify the production of the coupling device, in particular when the expansion valve is not positioned horizontally, that is to say that at least one of its ports is not aligned with a port of the exchanger. According to the invention, the duct is in fact formed by making a number of parts cooperate with one another, in particular an parts such as the exchanger and/or the expansion valve. The formation of the duct in the part or parts of the coupling device is thus simplified compared to the production by drilling of a bent passage in the body of a single block. 
         [0011]    According to an advantageous embodiment of the invention, said first part is intended to be pressed flat onto the exchanger and comprises through holes intended to cooperate respectively with the ports of the exchanger. Said second part is intended to be pressed flat onto the first part and comprises two through holes intended to cooperate respectively with the ports of the expansion valve. The holes of the parts are further in fluidic communication to define said first passage as well as a second passage intended to couple the other ports of the exchanger and of the evaporator. 
         [0012]    It is in fact easy to form through holes in parts, for example by machining, or to form parts directly with holes, for example from casting. The parts of the device are preferably metal, and for example made of aluminum and/or aluminum alloys. 
         [0013]    In the present application, the concept of “through holes” should be understood to mean holes which pass through a part, that is to say whose ends emerge on opposite faces of the part, these passages extending preferably in a direction intended to be substantially parallel to the axes of the ports of the exchanger and/or of the expansion valve. 
         [0014]    The parts are stacked and fixed together and to the exchanger, for example by brazing. In the assembled position, the holes of the parts define the passages coupling the ports of the exchanger to the ports of the expansion valve. The fact that the first part is pressed flat and fixed onto the exchanger, and for example onto an end plate of this exchanger, makes it possible to close the first passage in a seal-tight manner, on the side of the exchanger. The fact that the second part is pressed flat and fixed onto the first part makes it possible to close the first passage in a seal-tight manner, on the side of said second part. Furthermore, the holes of said parts are linked in seal-tight manner to one another and with the ports of the exchanger and of the expansion valve. 
         [0015]    In a preferred embodiment of the invention, the holes of the first part are formed respectively by an opening or slit of elongate form, defining, with said exchanger and/or said second part, said first passage, and by an orifice, defining said second passage. 
         [0016]    At least a part of the slit can have an incurved form about en axis of the orifice of the first part. This incurved part can have a radius of curvature, taken substantially at the middle of the slit, which is substantially equal to a center distance between the holes of the second part. This makes it possible to allow the adjustment of the angular position of the second part with respect to the first, about the axis of the orifice of the first part. The angular range over which the incurved part of the slit extends corresponds substantially the angular range of adjustment of position of the second part with respect to the first. This also makes it possible to provide a single reference (called standard part) for said first part, this reference being able to be associated with a number of different references for the second part, the references of the second part being able to differ from one another by the positions of their holes. 
         [0017]    The slit can comprise a rectilinear part of which one end is linked to the incurved part of the slit and of which the opposite end is intended to cooperate with a port of the exchanger. 
         [0018]    One of the holes of the second part can emerge in the incurved part of the slit of the first part. 
         [0019]    The first part can be formed by a plate or a sheet. 
         [0020]    In the case where a sheet is used, the latter can be stamped, the sheet comprising at least two indented zones at the bottom of which the holes are formed, for example by drilling. 
         [0021]    The second part can be formed by a metal block, and its holes can be formed by orifices. 
         [0022]    Said device will be able to comprise tubular bushings into which some of the holes of the second part emerge. 
         [0023]    Some of these tubular bushings can protrude on a face of the second part, which is situated on the side opposite the first part, and which intended to be inserted into the ports of the expansion valve. These bushings simplify the assembly and the positioning of the expansion valve on the coupling device. 
         [0024]    Others of these tubular bushings can protrude on a face of the second part, which is situated on the side of the first part, and which are intended to be inserted into the holes of this first part. These bushings simplify the assembly and the positioning of the parts on one another. 
         [0025]    The present invention relates also to an assembly comprising a heat exchanger such as an evaporator, an expansion valve, and a coupling device as described above. 
         [0026]    The present invention relates also to a method tor assembling a device as described above, in which the part or parts are pressed flat and fixed onto one another and/or between said exchanger and said expansion valve, for example by brazing, depending on the desired angular position of the expansion valve. 
         [0027]    Advantageously, the second part is positioned in relation to the first part such that one of the holes of the second part is substantially aligned on the axis of a corresponding hole of the first part, the second part being positioned angularly in relation to the first part about the abovementioned alignment axis, to obtain the orientation desired for the expansion valve. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0028]    The invention will be better understood and other details, features and advantages of the invention will become apparent on reading the following description given as a nonlimiting example and by referring to the attached drawings, in which: 
           [0029]      FIG. 1  is a partially exploded perspective schematic view of an assembly comprising on evaporator, an expansion valve and a device for coupling the evaporator to the expansion valve, according to the invention; 
           [0030]      FIG. 2  is a view on a larger scale of the expansion valve and of the coupling device of  FIG. 1 ; and 
           [0031]      FIGS. 3 to 6  are views similar to those of  FIG. 2  and representing variant embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Reference is first of all made to  FIG. 1  which represents an exchanger  10  of the evaporator type, notably for an air conditioning device of the interior of a motor vehicle. This exchanger  10  comprises, for example, a stack of exchange plates  12  arranged between two end plates  14 ,  16 . 
         [0033]    The plates will be able to be grouped in pairs to form a tube allowing a flow of refrigerant between the plates of a some pair of plates. Between two neighboring tubes, said exchanger will be able to comprise separators making it possible to increase the exchange surface area with a flow of air passing through the exchanger by passing between the tubes. Said plates comprise, at at least one of their ends, connection means, such as added-on stamped parts or flanges, forming manifolds making it possible to pass the refrigerant from one pair of plates to the other and emerging at at least one 16 of said end plates. 
         [0034]    This latter comprises a fluid inlet port  18  in the exchanger and a fluid outlet port  20  of the exchanger, communicating here with said manifolds. As can be seen in  FIG. 1 , in the position (vertical) of use of the exchanger, the axes of the ports  18 ,  20  which are parallel extend in a horizontal plane P 1 . 
         [0035]    The ports  18 ,  20  of the exchanger  10  are linked to ports  22 ,  24  of an expansion valve  26  via a coupling device  28  according to the invention. 
         [0036]    In the case represented in  FIG. 2 , the expansion valve  26  is in the vertical position and the axes of its ports  22 ,  24  are parallel to one another and to the axes of the ports  18 ,  20 , and extend in a vertical plane P 2  which passes through a bulb  30  of the expansion valve, which is here in a high position. 
         [0037]    The part  22  of the expansion valve  26  is aligned on the port  20  of the exchanger  10  and the port  24  of the expansion valve  26  is not aligned on the port  10  of the exchanger. 
         [0038]    The coupling device  20  according to the invention ensures the fluidic communication between the ports  20  and  22 , on the one hand, and the ports  18  and  24 , on the other hand, and here comprises an assembly or stack of two parts  30 ,  32 . 
         [0039]    A first part  30  of the device  28  is pressed flat against the and plate  16  and comprises two through holes  34 ,  36  fluidically linking to the ports  18 ,  20  of the exchanger. This part  30  is here formed by a plate of small thickness (for example between 1 and 10 mm) with substantially rectangular outline. The passage of the holes  34 ,  36  is here produced in a direction parallel to the ports  1 B- 24 . 
         [0040]    The hole  34  is formed by a cylindrical orifice aligned on the axis of the port  20  of the exchanger. The hole  36  is formed by a substantially L-shaped slit of elongate form. This slit comprises a first rectilinear and vertical  38 , the top end of which is situated facing the port  18  of the exchanger, is in the plane P 1 , and serves to fluidically link with this port. The rectilinear part  38  is linked by its bottom and to the top end of an incurved part  40  of the slit, the bottom and of which is situated substantially facing the port  24  of the expansion valve, and is in the plane P 2 . The part  40  is incurved about an axis A which is the axis of the hole  34  and of the port over an angular range of approximately 45° in the example represented. The radius of curvature R of this incurred part  40  is measured between the axis A and the middle of the slit. 
         [0041]    When the part  30  is applied and fixed, for example by brazing, onto the end plate  16 , the ports  18 ,  20  are in fluidic communication with the top and of the hole  36  and with the hole  34 , respectively. The end plate  16  blocks the rest of the hole  36  in a seal-tight manner, on the side of the exchanger. 
         [0042]    The second part  32  of the device is pressed flat against the first part  30  and comprises two through holes  42 ,  44  fluidically linking to the ports  2 ,  24  of the expansion valve. This part  32  is here formed by a substantially parallelepipedal metal block that has, for example, a thickness of between approximately 5 and 20 mm. The passage of the holes  42 ,  44  is here produced in a direction parallel to the ports  18 - 24 . The holes  42 ,  44  are each formed by a cylindrical orifice. The orifice  42  is aligned on the axis A, that is to say on the hole  34  of the first plate  30  and on the ports  20  and  22 . The orifice  44  is aligned on the axis B of the port  24  of the expansion valve and is facing the bottom end of the incurved part  40  of the hole  36  of the first part  30 . The center distance between the holes  42 ,  44  is substantially equal to the abovementioned radius R. The hole  42  thus ensures the fluidic communication between the hole  34  and the port  22 , and the hole  44  ensures the fluidic communication between the hole  36  and the port  24 . 
         [0043]    The part  32  comprises, on its face oriented toward the expansion valve  26 , two protruding cylindrical bushings  46 , which surround the corresponding ends of the holes  42 ,  44 . These bushings  46  are intended to be inserted into the ports  22 ,  24  of the expansion valve  26 , to facilitate the positioning and mounting thereof. 
         [0044]    The part  32  further comprises, on this same face, two tapped holes  48  which are intended to receive fixing screws (not represented) for the expansion valve  26 , the expansion valve comprising two orifices  50  for the passage of these screws. 
         [0045]    When the part  32  is applied and fixed, for example by brazing, onto the part  30 , the holes  34  and  42  are in fluidic communication and the hole  44  is in fluidic communication with the hole  36  by its bottom end, the rest of this hole  36  being blocked in a seal-tight manner by the covering of the plate  30  by the plate  32 . 
         [0046]    The slit  36  of the part  30 , closed laterally here by the end plate  16  of the exchanger and by the neighboring part  32 , thus defines a duct for the fluid between the two non-aligned ports  18 ,  24 . By combining a number of parts together, a passage is therefore formed between said ports without having to involve complex machining or casting operations generally associated with the bulk production of bent ducts. 
         [0047]    The expansion valve is mounted on the plate  32  by inserting the bushings  46  of this plate  32  into the ports  32 ,  24  of the expansion valve, then the above-mentioned screws are mounted in the orifices  50  and screwed into the holes  40  to join together the assembly. 
         [0048]    The arrows f 1  to f 9  represent the path of the fluid from the outlet port  20  of the exchanger to the inlet port  22  of the expansion valve, by passing through the holes  34 ,  42  of the device and from the outlet port  24  of the expansion valve to the inlet  18  of the exchanger, by passing through the holes  44 ,  36  of the device. As a variant, this path could be reversed. 
         [0049]    In the exemplary embodiment of  FIGS. 1 and 2 , the expansion valve  20  is in the vertical position. In the variants represented in  FIGS. 3 and 4 , it is in the inclined position. In these variants, the part  30  is identical to that described previously and thus constitutes a standard part that can be used for a number of embodiments of the invention. 
         [0050]    In the variant of  FIG. 3 , the part  32 ′ differs from the part  32  described above through the position of its hole  44  which is intended, in the assembled position, to be facing the top end of the inclined part of the hole  36  of the part  30 . In this case, the plane P 2  of orientation of the expansion valve in which the axes of the holes  42 ,  44  of the part  32 ′ extend, is inclined, here by an angle of approximately 45′. In the assembly position, the peripheral edges of the parts  30 ,  32 ′ are substantially aligned with one another. 
         [0051]    The embodiments of  FIGS. 2 and 3  show that a number of different parts  32 ,  32 ′ references can be associated with a single reference of a so-called standard part  30 . 
         [0052]    In the variant of  FIG. 4 , the part  32  is identical to the part  32  of  FIGS. 1 and 2  but is positioned differently in relation to the part  30 . The part  32  has undergone a rotation of 45° about the axis A such that its hole  44  is facing the top end of the inclined part of the hole  36  of the part  30 . 
         [0053]    The embodiments of  FIGS. 2 and 4  show that two standard parts  30 ,  32  can be used to produce a coupling of the exchanger to an expansion valve having any orientation, so long as the second part  32  laterally closes the hole  36 . 
         [0054]      FIGS. 5 and 6  represent other variant embodiments of the coupling device according to the invention, in which the first part  130 ,  130 ′ is formed by a stamped sheet, which has a substantially rectangular outline. 
         [0055]    The part  130  of  FIG. 5  comprises two zones  152 ,  154  indented by stamping. The bottoms of these zones  152 ,  154  are substantially flat and extend in a plane parallel to and at a distance from the plane of the sheet. The first hole  134  is formed in the bottom of the first zone  152  and has a substantially circular outline. The second hole  136  is L-shaped comparable to the shape of the abovementioned hole  36 , and is formed in the bottom of the second zone which is also generally L-shaped. 
         [0056]    The holes  134 ,  136  can be formed during the stamping operation or thereafter. 
         [0057]    The second part  132  of  FIG. 5  differs from the part of  FIG. 2  essentially in that it further comprises, on its face oriented toward the first part  130 , two protruding cylindrical bushings  155  which surround the corresponding ends of the holes  142 ,  144  of the part  132 . The bushings  156  are intended to be inserted into the holes  134 ,  136  of the first part  130 , to facilitate the positioning and mounting thereof. The bushing  156  of the hole  142  is intended to be inserted into the hole  14 , and the bushing  156  of the hole  144  is intended to be inserted into the bottom end of the incurved part of the hole  136 , such that the expansion valve, intended to be fixed onto the part  132  has a vertical position. 
         [0058]    For that, the hole  134  has a diameter slightly greater than the outer diameter of the bushing  156  of the hole  142 , and the bottom end of the incurved part of the hole  136  has a transverse dimension slightly greater than the outer diameter of the bushing  156  of the hole  144 . 
         [0059]    The second part  132  is configured to laterally close the hole  136 . 
         [0060]    The part  130 ′ of  FIG. 6  differs from the part  130  of  FIG. 5  that the hole  136 ′ formed in the bottom of the zone  154  has a circular outline and is situated at the level of the top and of the incurved part of the hole  136  of  FIG. 5 . This hole  136 ′ has a diameter slightly greater than that of the bushing  156 . The part  132  of  FIG. 6  is identical to that of  FIG. 5 , except that it will be able to have a reduced extension because its function is no longer to laterally close the duct linking the port  18  to the orifice  136 ′, said duct being here laterally closed by the bottom of the stamped part, on the side of said second part  132 . 
         [0061]    The parts  130 ,  132  and  130 ′,  132  can also be fixed together and to the exchanger by brazing, notably when brazing the different parts of the exchanger.