Abstract:
A heat exchanger comprises a housing adapted to surround a heat exchange bundle. The housing is provided with an opening for receiving the heat exchange bundle in the interior of the housing. The heat exchange bundle comprises a first extremity adapted to close the opening in the housing when the heat exchange bundle is inserted in the interior of the housing. A second extremity of the heat exchange bundle opposite the first extremity is provided with at least one protuberance, and the wall of the housing is provided with a contact element adapted to support the protuberance in order to limit the movement of the second extremity of the heat exchange bundle in relation to the wall of the housing.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a heat exchanger, for example a heat exchanger intended for an automobile. More precisely, the invention relates to a heat exchanger permitting the exchange between a first fluid and a second fluid, in which the first fluid is a fluid such as air, for example, and the second fluid is a liquid fluid such as water, for example. The heat exchanger according to the present invention is particularly adapted for use for cooling of the charge air. 
       STATE OF THE ART 
       [0002]    These days, the internal combustion engines of automobiles are frequently supplied with compressed air in order to improve the performance of the said engines. This compressed air is often designated using the expression “charge air”. The compressed air is obtained by the use of a compressor driven by the exhaust gas. Consequently, the effect of compressing the air is to heat the compressed air. It has been found necessary to cool the compressed air prior to its introduction into the interior of the engine, in order to lower the temperature of the said compressed air prior to its introduction into a cylinder of the engine. 
         [0003]    Already familiar for the purpose of cooling the compressed air is the use of a heat exchanger comprising a heat exchange bundle constituted by an assembly of plates, positioned one on top of the other and forming, in combination, a conduit permitting a first fluid such as a liquid to be guided from an inlet towards an outlet. In order to improve the exchange of heat, the assembly of the plates is supplemented by corrugated spacer elements. The heat exchange bundle is positioned in the interior of a casing or a housing. This housing is provided with an inlet and an outlet for the second fluid to be cooled, such as air, and is adapted to guide the second fluid from an inlet towards an outlet. The housing performs the function of a header box enclosing the said heat bundle and permitting the admission and the regulation of the charge air. Such a housing is molded, for example, in a material such as aluminum or plastic. 
         [0004]    In practice, the walls of the housing are relatively thin and relatively flexible. Thus, when using the housing, the volume of the said housing may increase depending on the increase in the pressure and in the temperature in the interior of the housing. 
         [0005]    The housing of a heat exchanger is provided, according to the prior art, with an opening permitting the introduction of the heat exchange bundle into the interior of the housing. In practice, the housing is essentially in the form of a box comprising five walls. The sixth wall is omitted in order to permit the heat exchange bundle to be introduced into the interior of the housing by displacing the said exchange bundle towards the interior of the housing in a direction of introduction. When the heat exchange bundle is in place, the sixth wall of the housing is formed by a top cover, to which a first extremity of the exchange bundle is secured. For this type of application, the top cover permits the assembly consisting of the plates and the corrugated spacer elements of the heat exchanger to be connected and the whole to be secured to the said top cover. The top cover is provided with conduits permitting the fluid, such as a liquid, to enter into the interior of the heat exchanger and to exit from the heat exchanger. The top cover secured to the heat exchange bundle performs a function of closing the opening which permits the introduction of the heat exchanger. Thus, in a first stage, the heat exchange bundle is surrounded or enclosed by the walls of the housing and, in a second stage, is enclosed by the top cover. 
         [0006]    In its operating position, the top cover, to which the heat exchange bundle is secured, is in principle positioned in an essentially horizontal manner above the said heat exchange bundle. In other words, the heat exchange bundle is suspended from the top cover. 
         [0007]    The heat exchangers that are known from the prior art have a number of disadvantages. In the first place, the connection between the housing and the top cover is very fragile and is required to withstand both high pressure and the high temperatures that are present in the interior of the heat exchanger. In addition, the walls of the housing are capable, during normal use of the heat exchanger, of deforming under the pressure of the hot air that is present in the interior of the said heat exchanger. This deformation, which remains constant during operation of the heat exchanger, may give rise to premature wear of the material used during the manufacture of the housing. The reliability of the housing may be adversely affected as a result. 
         [0008]    In addition, to the extent that the heat exchange bundle is suspended from the top cover, the heat exchange bundle may exhibit pendular movements under the influence of the vibrations imposed by the operation of the engine of the vehicle with which the heat exchanger is being used. The repetition of these pendular movements, in particular in the presence of a resonance effect, may produce a negative influence on the reliability of the heat exchanger. 
       OBJECT OF THE INVENTION 
       [0009]    The heat exchanger according to the present invention is intended to overcome the disadvantages of heat exchangers, as disclosed in the prior art, by proposing a new design regarding the securing of a heat exchange bundle in the interior of the housing of a heat exchanger. 
         [0010]    For this purpose, the present invention relates to a heat exchanger comprising a housing adapted to surround a heat exchange bundle, the said housing being provided with an opening for receiving the said heat exchange bundle in the interior of the said housing, the said heat exchange bundle comprising a first extremity adapted to close the opening in the housing when the heat exchange bundle is inserted into the interior of the said housing, in which a second extremity of the heat exchange bundle opposite the said first extremity is provided with at least one protuberance, and in which the wall of the housing is provided with a contact element adapted to support the said protuberance in order to limit the movement of the second extremity of the heat exchange bundle in relation to the said wall of the housing. 
         [0011]    The limitation of the pendular movement of the heat exchanger resides in the fact that the second extremity of the heat exchange bundle is incapable of displacement in relation to the walls of the housing due to the presence of at least one protuberance and the contact element adapted to ensure contact with the said protuberance. In other words, the securing of the connection between the housing and the top cover is improved by the absence of pendular movement of the exchange bundle in relation to the housing under the influence of the vibrations imposed by the operation of the engine of the vehicle with which the heat exchanger is being used. 
         [0012]    According to one particular embodiment of the invention, the heat exchange bundle is introduced into the interior of the housing in a direction of introduction, the protuberance extending essentially in the said direction of introduction, and the said contact element being adapted to support the protuberance in order to limit the movement of the said protuberance in relation to the wall of the housing in a direction essentially perpendicular to the direction of introduction. 
         [0013]    According to one particular embodiment of the invention, the wall of the housing is provided with an opening allowing the said protuberance to pass through the said wall of the said housing. 
         [0014]    According to one particular embodiment of the invention, the contact element is adapted to be secured to the exterior of the wall of the housing in order to support the protuberance and to cover the said opening. 
         [0015]    According to one particular embodiment of the invention, the protuberance is essentially in the form of a peg. 
         [0016]    According to one particular embodiment of the invention, the contact element is essentially in the form of a cap. 
         [0017]    According to one particular embodiment of the invention, the heat exchange bundle comprises an assembly of plates together with corrugated spacer elements, in which the plates and the corrugated spacer elements and the said at least one protuberance are assembled by means of a brazing process. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0018]    The purpose, object and characterizing features of the present invention, as well as its advantages, will be appreciated more clearly from a perusal of the following description of the preferred embodiments of a heat exchanger according to the invention, which description is given with reference to the drawings, in which: 
           [0019]      FIG. 1  illustrates a view, in perspective, of a heat exchanger within a housing according to a first embodiment of the present invention, with an exterior part of the housing removed in order to reveal the elements that are present in the interior of the said heat exchanger, by way of example; 
           [0020]      FIG. 2  depicts in detail the securing of the heat exchange bundle to the walls of the housing of the heat exchanger, by way of example; 
           [0021]      FIG. 3  illustrates, in a schematic manner, the securing of the heat exchange bundle to the walls of the housing of the heat exchanger, the said securing including three protuberances that are secured to the second extremity of the exchange bundle and extending beyond the wall of the said housing, and 
           [0022]      FIG. 4  depicts, in a schematic manner, the securing of a protuberance permitting the movements of the said protuberance to be limited in relation to the wall of the housing through a contact element in the form of a “cap”. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0023]      FIG. 1  illustrates a perspective view of an embodiment of a heat exchanger  1  according to the present invention. One part of the exterior of the heat exchanger  1  has been removed in order to illustrate the interior of the said heat exchanger  1 . 
         [0024]    The heat exchanger  1  as illustrated in  FIG. 1  is adapted in particular for use in the automobile industry in order to cool the charge air of an internal combustion engine (as charge air coolers). The heat exchanger  1  allows the charge air to be cooled, for example, by the exchange of heat with a first fluid, such as the exterior air, or with a liquid, such as the cooling water of an engine, thereby forming an exchanger of the air/air or liquid/air type. 
         [0025]    First, the heat exchanger  1  comprises an inlet manifold  2 , frequently referred to by a person skilled in the art under the English designation “intake manifold”. The inlet manifold  2  is secured to the cylinder head of the combustion chamber of the engine (not illustrated here), that is to say to the inlet into the cylinder. Depending on the speed of the engine, the air may be cooled either totally or partially, or the air may not be cooled. The inlet manifold  2  is connected to a housing  3 . The housing  3  forms an envelope intended to surround a heat exchange bundle  4  that is present in the interior of the said housing  3 . 
         [0026]    The heat exchange bundle  4  according to the present invention is positioned in the interior of a housing  3 . The housing  3  is provided with an inlet and with an outlet for a first gaseous fluid and is adapted to guide the said first fluid from an inlet towards an outlet. 
         [0027]    The heat exchanger  1  according to the present invention comprises a heat exchange bundle  4  constituted by an assembly of plates, positioned one on top of the other and forming, in combination, a conduit permitting a second liquid fluid, used for cooling the first liquid fluid, to be guided from an inlet towards an outlet. In order to improve the exchange of heat, the assembly of the plates is supplemented by corrugated spacer elements. 
         [0028]    According to a known operating function, a first fluid, such as air, passes over the exterior of the heat exchange bundle  4 , and a second fluid, such as the water in the cooling circuit, circulates in the interior of the heat exchange bundle  4  and, by so doing, permits the air to be cooled. 
         [0029]    The heat exchange bundle  4  is formed by an assembly of stamped plates, also referred to as “half blades”. However, the invention also relates to other types of bundles, and in particular to bundles including tubes and fins. The heat exchange bundle  4 , as illustrated in  FIG. 2 , is formed by a stack of stamped plates arranged in pairs and of identical design. Only the two end plates forming the upper extremity and the lower extremity of the heat exchange bundle  4 , as illustrated in  FIG. 1 , are of a different shape in relation to the stacked stamped plates. 
         [0030]    Each stamped plate exhibits a rectangular shape and includes a substantially plane bottom wall, bounded by a peripheral edge of rectangular shape and elevated in relation to the bottom wall in order to form a shallow trough. Each pair of stamped plates delimits a chamber. The use of a plate of this type is familiar to a person skilled in the art. 
         [0031]    The stamped plates, arranged in pairs, form the heat exchange bundle  4 . The respective boss of a stamped plate belonging to a pair is in communication with the respective boss of an adjacent stamped plate belonging to a part of the neighboring stamped plates. 
         [0032]    The heat exchange bundle  4  comprises corrugated spacer elements  5 , as illustrated in  FIG. 2 , arranged between pairs of adjacent stamped plates. The different stamped plates and the corrugated spacer elements  5  are assembled, according to a known technique, by a brazing process. After assembly, the heat exchange bundle  4  delimits first channels for the gas to be cooled, present inside which channels are the corrugated spacer elements  5 , and second channels (not illustrated here) for the circulation of the cooling liquid obtained by the use of plates. 
         [0033]    The component parts of the heat exchange bundle  4  comprising the stamped plates, the corrugated spacer elements  5 , the inlet manifold and the inlet tubes and outlet tubes for the cooling liquid are produced advantageously in an alloy of aluminum, are assembled together and are brazed in a single operation in a brazing oven. 
         [0034]    As illustrated in  FIG. 1 , the upper part of the heat exchange bundle  4  is secured to a closing element  6 , such as a plate or a top cover  6 . The top cover  6  performs several functions. One of these functions is to permit an inlet and an outlet of the cooling liquid by means of tubes arranged in the top cover  6 . Furthermore, the top cover  6  forms the closing element of the housing  3 . Thus, when the heat exchanger  1  is assembled, the heat exchange bundle  4  is surrounded, on the one hand, by the walls formed by the housing  3  and, on the other hand, by the top cover  6 . 
         [0035]    As illustrated in  FIG. 2 , the heat exchanger  1  according to the present invention is provided with a protuberance  21  which is secured to the lower extremity of the heat exchange bundle  4 . The protuberance  21  is in the form of a peg and is adapted in order to pass through the lower wall  31  of the housing  3  and to be secured to the said lower wall  31  of the housing  3  by any suitable means, as illustrated in  FIG. 4 . 
         [0036]      FIG. 2  depicts in detail a first embodiment of the protuberance  21 .  FIG. 2  shows that the lower wall  31  of the housing  3  includes an opening allowing the said protuberance  21  to pass through. The protuberance  21  is secured to the lower extremity of a heat exchange bundle  4  by a brazing process. This signifies that, during assembly of the heat exchange bundle  4 , a single operation, carried out in a brazing oven, permits a heat exchange bundle  4  to be assembled and the protuberance  21  to be secured on the lower wall  31  of the heat exchange bundle  4 . 
         [0037]      FIG. 3  illustrates in a schematic manner the securing of the heat exchange bundle  4  in the interior of the housing  3  comprising three protuberances  21 ,  22 ,  23 . 
         [0038]    In the first place,  FIG. 3  shows that the heat exchange bundle  4  has been introduced into the interior of the said housing  3  by displacing the said heat exchange bundle  4  in the direction of introduction indicated by the arrow  45 . Such an introduction is achievable thanks to an almost total opening in the upper wall  32  of the housing  3 . The introduction of the heat exchange bundle  4  towards the interior of the housing  3  is also possible by the displacement of the heat exchange bundle of the upper wall  32  in the direction of the lower wall  31  of the housing  3 . 
         [0039]    When the heat exchange bundle  4  has been introduced completely into the interior of the housing  3 , the upper wall  32  of the housing  3  is formed by the top cover  6  from which the heat exchange bundle  4  is suspended. The top cover  6  is secured to the upper wall  32  using any suitable means, for example screws. The said lower wall  31  is provided with openings  35 ,  36 ,  37  in order to secure the second extremity of the heat exchange bundle  4  to the lower wall  31 . 
         [0040]    As illustrated in  FIG. 3 , the size of the openings  35 ,  36 ,  37  is relatively large in relation to the size of the protuberances  21 ,  22 ,  23 . Thus, the difference in size between the size of the openings  35 ,  36 ,  37  and that of the protuberances  21 ,  22 ,  23  facilitates the introduction of the heat exchange bundle  4  according to the invention as well as its assembly. Furthermore, the size of the openings  35 ,  36 ,  37  of the heat exchanger  4  according to the invention permits the component parts of the said heat exchanger according to the invention to be assembled with a relative tolerance with respect to the dimensions of the said component parts, but without compromising the assembly of the said heat exchanger  4 . When the heat exchange bundle  4  is correctly positioned in the interior of the housing  3 , the extremities of the protuberances  21 ,  22 ,  23  are secured in relation to the lower wall  31  of the housing  3 . The securing of the protuberances  21  on the lower wall  31  is illustrated in  FIG. 4 . 
         [0041]      FIG. 4  depicts the securing of the extremity of the protuberance  21  in relation to the lower wall  31 , the said securing using a contact element  50  in the form of a hat or a cap. The contact element  50  is provided with a first element  51  adapted to receive within it the extremity of the protuberance  21 . The contact element  50  comprises a second element  52  adapted to secure the said contact element  50  to the lower wall  31 . The second part  52  has dimensions adapted to close the opening  35  permitting the passage of the protuberance  21  through the lower wall  31 . 
         [0042]    As illustrated in  FIG. 4 , the movement of the protuberance in relation to the wall  31  is possible, in a normal function of the heat exchanger  4  and in the longitudinal direction of the protuberance  21 , when the extremity of the said protuberance  21  is secured in relation to the lower wall  31  of the housing  3 , using the contact element  50 . On the other hand, the movement of the protuberance  21  is limited, in relation to the movement of a heat exchanger according to the state of the art, in the direction perpendicular to the longitudinal direction of the protuberance  21 . 
         [0043]    Thus, with reference to  FIG. 3 , the movement of the protuberance  21  is possible in the direction of introduction  45  of the heat exchange bundle  4 . On the other hand, the movement of the said protuberance  21  is limited in a perpendicular direction in relation to the said direction of introduction  45 . 
         [0044]    The protuberances  21 ,  22 ,  23 , as illustrated in  FIGS. 1 ,  2 ,  3  and  4 , may be in an essentially cylindrical form or, alternatively, in a square form. The protuberances  21 ,  22 ,  23  may be made of aluminum. Thus, the said protuberances may be secured to the heat exchange bundle  4  in the course of the assembly of the said heat exchange bundle  4  during a brazing process. 
         [0045]    Alternatively, the protuberances  21 ,  22 ,  23  may be produced using a plastic material. The contact element  50  may be made of a plastic material. Thus, when the lower wall  31  of the housing  3  is made of the same type of plastic material, the contact element  50  may be secured to the lower wall  31  of the housing  3 , for example by a method of ultrasonic welding, by a method of welding that is familiar under the English designation “hot plate welding” or also by any suitable adhesive means such as a glue. 
         [0046]    As illustrated in  FIG. 4 , a first free space  61  is present between the lower extremity of the heat exchange bundle  4  and the lower wall  31 . This free space makes a clearance possible during the assembly and the utilization of the heat exchange bundle  4  and of the housing  3 . 
         [0047]    A second free space  62  is present between the extremity of the protuberance  21  and the interior of the first part  51  of the contact element  50 . This second free space  62  permits the avoidance of all pressure on the protuberance  21  and, consequently, on the lower extremity of the heat exchange bundle  4  after assembly. 
         [0048]    When the protuberances  21 ,  22 ,  23  are secured on the lower wall  31  of the housing  3 , a plurality of technical effects are produced. In particular, the rigidity of the heat exchanger  1  increases. 
         [0049]    Furthermore, when the lower wall of the heat exchange bundle  4  is secured to the wall  31  of the housing  3 , this heat exchange bundle  4  is no longer able to perform a pendular movement. In other words, the detrimental effect of wear caused by the pendular movements is consequently suppressed. 
         [0050]    Within the examples of embodiments described above, it is stated that the securing elements  21 ,  22 ,  23  may be secured to the lower extremity of the heat exchange bundle  4  by a brazing process. Any other method for the securing of securing elements may be envisaged, for example by the use of a suitable adhesive means.