FR2996295A1 - HEAT EXCHANGER, IN PARTICULAR FOR A MOTOR VEHICLE, AND ASSOCIATED ASSEMBLY METHOD. - Google Patents

Abstract

The present invention relates to a heat exchanger (1), comprising: - a bundle (7) of flat tubes (70) with wide ends (72), - a housing (3) surrounding said bundle (7) and sealingly attached at the widened ends (72) of the flat tubes (70), said casing (3) defining a sealed chamber in which a first fluid circulates between the flat tubes (70) from an inlet (37a) to an outlet (37b), - a an inlet housing (5a) and an outlet housing (5b) of a second fluid, said housings (5a, 5b) being positioned at the ends of the beam (7) and being sealingly attached to the ends of the housing (3 ), the ends of the housing (3) having a flare (32) at each end, said flare (32) forming, in cooperation with the ends of the beam (7), a fixing groove (34) into which is inserted the receiving housing (5a) or the output housing (5b).

Description

Heat exchanger, in particular for a motor vehicle, and associated assembly method.

The invention relates to a heat exchanger, in particular for a motor vehicle. The invention also relates to methods of assembling such a heat exchanger. A heat exchanger, for example used in the automotive industry and more specifically in an internal combustion engine of a motor vehicle, comprises heat exchange elements and fluid flow in which heat exchanging fluids circulate. between them. The heat exchange elements may for example comprise tubes or plates, gas flow disturbing fins and / or fluid flow disruptors or the like. Many structural configurations are possible. Exchangers are known comprising a bundle of flat tubes arranged parallel to one another on one or more parallel rows with one another, these tubes being arranged to allow the circulation of a first fluid between said flat tubes and, on the other hand, to allow the circulation a second fluid inside said flat tubes, exchanging heat with the first fluid.

A known structure of such a bundle is a stack of flat tubes with enlarged ends, the flat tubes being fixed together at their widened ends. According to a known solution, the bundle of flat tubes is contained inside a casing connected to a circuit of the first fluid and delimiting the circulation space of said first fluid between the flat tubes. The ends of the bundle and housing are also generally connected to a manifold and an inlet housing and an outlet housing of the second fluid for the circulation of the second fluid within the flat tubes.

Many fluid associations can be envisaged, be they liquids and / or gases. However, the manufacture of such exchangers is expensive because it requires many parts and a verification process to ensure the seal between the first and second fluid circuits. The invention therefore aims to at least partially meet the disadvantages of the prior art and to provide a low-cost heat exchanger and ensuring an optimum seal between the circulations of the first and second fluid. The invention therefore relates to a heat exchanger for transferring heat between a first and a second fluid, said heat exchanger comprising: - a bundle of flat tubes with extended ends, said widened ends being in direct contact with one of the other and fixed to each other in a sealed manner, - a casing surrounding said bundle and sealingly attached to the enlarged ends of the flat tubes, said casing defining a sealed chamber in which the first fluid flows between the flat tubes of the bundle from an inlet to an outlet of said first fluid, an inlet housing and an outlet housing of the second fluid, said housings being positioned at the ends of the bundle and being sealingly attached to the ends of the housing, said second fluid flowing inside the flat tubes of the bundle, the ends of the casing having a flare at each end, said flare ent forming, in cooperation with the ends of the beam, a fixing groove in which is inserted the inlet housing or the outlet housing of the second fluid.

The fact that the fixing groove is directly formed between the flaring of the casing and the end of the bundle makes it possible to simplify the assembly of the heat exchanger as well as to limit the manufacturing costs by limiting the number of parts required for its assembly.

According to one aspect of the invention, the housing comprises four independent walls fixed to each other and forming said housing. According to another aspect of the invention, the independent walls are fixed together by brazing.

According to another aspect of the invention, the housing is brazed to the beam. In another aspect of the invention, the enlarged ends of the flat tubes have a rectangular cross-sectional shape. According to another aspect of the invention, the inlet and the outlet of the first fluid are formed on the same wall of the housing. According to another aspect of the invention, the fixing groove comprises a sealing means. According to another aspect of the invention, at least two flares at the end of the casing comprise folded release appendages on the inlet casing or the output casing of the second fluid.

According to another aspect of the invention, the heat exchanger is configured to cool the charge air of an engine in a motor vehicle.

The invention also relates to a method of assembling a heat exchanger for transferring heat between a first and a second fluid, comprising: a bundle of flat tubes with an enlarged end, said widened ends being in direct contact with one another; on the other and sealed to each other, - a housing, - an inlet housing and an outlet housing of the second fluid, said method comprising the following steps: - formation of a flare at the ends of the housing sealing of the beam inside the casing at the widened ends of the flat tubes, so that the flare at the ends of the casing, in cooperation with the ends of the beam, forms a fixing groove, and that said casing defines a sealed enclosure in which a first fluid circulates between the flat tubes of the bundle from an inlet to an outlet of the first fluid, - tight fixing of the arrival box and the outlet housing of the second fluid in the attachment groove, so that the second fluid flows inside the flat tubes of the bundle. Such a method allows a reduction in production costs by simplifying the fixing steps of the inlet and outlet housings within the fixing groove. According to one aspect of the assembly method, the latter comprises, between the step of sealing the flat bundle inside the housing and the sealing step of the inlet housing of the second fluid outlet housing in the fixing groove, an additional step of setting up a sealing means in the fastening groove. According to another aspect of the assembly process, the formation of a flare at the ends of the casing is achieved by stamping. According to another aspect of the assembly method, the casing comprises four independent walls forming said casing and that the fixing of said four independent walls is carried out during the step of sealing the beam 10 inside the casing. According to another aspect of the assembly process, the step of sealing the beam inside the housing is carried out by brazing. Other characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and nonlimiting example, and the appended drawings among which: FIG. 1 shows a perspective representation of a heat exchanger, FIG. 1b shows a semi-exploded view in perspective of the heat exchanger of the preceding figure; FIG. 2 shows a perspective representation of a flat beam tube; FIG. 3 shows a perspective view of a heat exchanger before assembly of the beam and the casing; FIG. 4 shows a sectional side view of the connection between a beam, a casing and the casing of a heat exchanger; Figure 5 shows a flowchart of the steps of a method of assembling a heat exchanger according to the invention.

In these figures, the substantially identical elements bear the same references. Figure la shows a heat exchanger 1 for heat transfer between a first and a second fluid, having a housing 3 provided with an inlet 37a and an outlet 37b of the first fluid. At the ends of said casing 3, the heat exchanger 1 comprises an inlet casing 5a and an outlet casing 5b of the second fluid. The housing 3 further comprises at its ends intended to be connected, a flare 32 forming a fixing groove 34 (not visible in Figure la, but visible in Figure lb) in which is inserted the arrival housing 5a or 5b output of the second fluid. In addition, at least two flares 32 at each end of the casing 3 may have blocking appendages 38 in order to maintain the inlet casing 5a and the outlet casing 5b in the fixing groove 34. FIG. 1b shows in more detail the inside of the heat exchanger 1 without the presence of the arrival boxes 5a and 5b output of the second fluid. The exchanger 1 comprises within it a beam 7 composed of flat tubes 70 stacked on each other. As shown in Figure 2, the flat tubes 7o 20 have enlarged ends 72. The widened ends 72, for example substantially rectangular in cross section, are fixed together to form the stack of flat tubes 7o constituting the beam 7, the attachment between the widened ends 72 of the flat tubes 7o being joined. The casing 3 surrounds said beam 7 and is fixed thereto in a sealed manner so as to delimit a sealed enclosure, in which the first fluid can circulate in the interstices 74 (visible in FIGS. 3 and 4) between the flat tubes 70 of said beam 7. The flat tubes 70 are preferably made of metal, their widened ends 72 can thus be made by stamping. The enlargement height may be of the order of imm so that the interstices 74 have a height of the order of 2MM and also to limit the stretching of material at the enlarged ends 72. The fixing of said flat tubes 7o between them in order to form the beam 7, can thus be achieved by brazing.

The casing 3 may be more particularly fixed to the beam 7 at the lateral surfaces 72b of the flat tubes 7o and on the flat surface 72a of the widened ends 72 of the flat tubes 7o at the top and at the base of the beam 7. The casing 3 may be in particular attached to the beam 7 only at the widened ends 72 of the flat tubes 7o, a space between the housing 3 and the side surfaces 72b being left to allow the flow of the first fluid over the entire height of the beam 7. In addition, the having rectangular enlarged ends 72, allows a more efficient fixing and thus a better sealing of the housing 3 around the beam 7. The fact that the widened ends 72 of the flat tubes 70 are contiguous, allows the ends of the beam 7 to be when the latter is fastened inside the casing 3, the second fluid arriving at one end of said beam 7 can not infiltrate the inside of the casing 3 The second fluid can then circulate inside the flat tubes 70 of the bundle 7. According to an alternative fastening mode, the casing 3 is fixed over the entire length of the tubes. lateral surfaces 72b of the flat tubes 70 and to allow the circulation of the first fluid over the entire height of the beam 7, the casing 3 comprises stampings 39 (visible in Figures la, lb and 3). The inlet 37a and the outlet 37b of the first fluid are preferably made on the walls of the casing 3 facing the interstices 74 between the flat tubes 70 of the bundle 7, so that the first fluid passes into the latter in order to allow a good heat exchange. The inlet 37a and outlet 37b of the first fluid may in particular be made on opposite walls or on the same wall of the casing 3. In the case where the casing 3 comprises stampings 39, said inlet 37a and outlet 37b of the first fluid may be performed on these. The housing 3 may preferably be made of metal and its attachment with the beam 7 when the latter is metallic, be made by brazing.

FIG. 3 shows an alternative embodiment in which the casing 3 comprises four independent walls 3a, 3h, 3c and 3d, for example metallic, fixed to each other, for example by brazing, and forming said casing 3. These independent walls 3a , 3h, 3c and 3d can thus be fixed to each other at the time of attachment of the beam 7 with the housing 3, allowing a good fit of the housing 3 around the beam 7 and cost savings. FIG. 4 shows, in sectional view, an end of a heat exchanger 1. It is thus possible to see that the fixing groove 34 is formed on one side by the flaring 32 of the casing 3 and on the other by the end of the beam 7. The inlet casing 5a or output 5b of the second fluid thus fits into the fixing groove 34 to guide the second fluid in the beam 7, inside the flat tubes 70 .

The fact that the fixing groove 34 is directly formed between the flaring 32 of the casing 3 and the end of the bundle 7 makes it possible to simplify the assembly of the heat exchanger 1 as well as to limit manufacturing costs by limiting the number of parts needed for its assembly.

The fixing groove 34 may further comprise a sealing means 9 placed inside thereof in order to improve the sealing and / or the fixing of the inlet casings 5a and of the outlet 5b of the second fluid. . This sealing means 9 may for example be a seal or glue. The inlet casings 5a and 5b of the outlet are inserted into the fixing groove 34 and their attachment can be achieved by gluing or crimping. The locking means 38 may be, for example, appendages of the casing 3 folded onto said inlet 5a and outlet 5b casings (as shown in FIGS. 1a, 1b, 3 and 4) or tie rods and reinforce the fixing and the maintaining said arrival boxes 5a and 5b output. The inlet boxes 5a and 5b outlet 5b can also be metal and thus can be fixed for example by welding. The heat exchanger 1 according to the invention can be particularly configured to cool the charge air of an engine in a motor vehicle. As shown in FIG. 1, the supercharging air, corresponding to the second fluid, arrives at the arrival box 5a, and passes into the bundle 7, inside the flat tubes 7o. A heat transfer fluid, for example a water and glycol mixture, acting as a first fluid and coming from a cooling circuit, enters through the inlet 37a, circulates between the flat tubes 7o of the bundle 7 inside the casing 3. Inside the casing 3, there is exchange of heat between the charge air and the coolant and the cooled supercharging air exits the outlet casing 5b in order to go towards the engine cylinders, while that the heated heat transfer fluid exits through the outlet 37b of the casing 3 to be cooled for example at a radiator in the cooling circuit. In order to improve heat exchanges between the first and second fluids, it is known to have turbulators (not shown) inside the flat tubes as well as disrupters (not shown) between said flat tubes 70.

The present invention also relates to a method of assembling a heat exchanger 1 illustrated in FIG. 5 and comprising the following steps: A first step 100 of the assembly method corresponds to the supply of the bundle 7 as well as the supply of the 3. The beam 7 may be previously completely made for example by soldering a stack of flat tubes 7o at their enlarged ends 72. The beam 7 may nevertheless be incomplete and comprise flat tubes 70 with extended ends 72 not fixed. still to each other. Similarly the housing 3 10 may be provided complete or may be composed of four independent walls 3a, 3h, 3c and 3d being intended to form said housing 3. A second step 102 of the assembly process corresponds to the formation of a flare 32 at the ends of the housing 3, for example by stamping the latter or the four independent walls 3a, 3h, 3c and 3d. The third step 104 of the assembly process corresponds to the sealed attachment of the beam 7 inside the casing 3. This attachment is made at the extended ends 72 of the flat tubes 70, so that the flaring 32 20 ends of the casing 3, in cooperation with the ends of the beam 7, forms a fixing groove 34, and that said casing 3 delimits a sealed enclosure in which a first fluid circulates between the flat tubes 70 of the beam 7 from an inlet 37a to a 37b output of the first fluid. This attachment can be made for example by soldering if the housing 3 and the beam 7 25 are both metallic. In the case where the housing 3 has four independent walls 3a, 3h, 3c and 3d, the latter are fixed to each other during this third step 104. It is the same in the case where the flat tubes 70 of the beam 7 are not fixed between them. Thus, during the same brazing, the four independent walls 3a, 3h, 3c and 3d and the beam 7 are fixed together allowing adjustment of the different parts together and thus ensure a good seal. The assembly method may comprise, following the third fixing step 104, an optional step 106 of placing a sealing means 9 inside the fixing groove 34, for example a seal or glue. A fourth step 108 corresponds to the sealed attachment of the inlet casing 5a and the outlet casing 5b of the second fluid in the fixing groove 34, so that the second fluid circulates inside the flat tubes 7o of the beam 7. This fixing is carried out in particular by insertion of said inlet boxes 5a and 5b exit into the fixing groove 34. The arrival boxes 5a and 5b exit can be thus glued, crimped or welded if they are metallic and their reinforced fixation by the locking means 38.

Such a method makes it possible to reduce production costs by simplifying the fixing steps of the arrival and exit casings 5a and 5b within the fixing groove 34.

Thus, it can clearly be seen that, because of the presence of a fastening groove 34 directly formed between the casing 3 and the ends of the beam 7, it is possible to fit the arrival boxes 5a and the outlet boxes 5b in order to obtain an economical heat exchanger but which nevertheless keeps a good seal. 25

Claims (14)

REVENDICATIONS1. Heat exchanger (1) for transferring heat between a first and a second fluid, said heat exchanger comprising: - a bundle (7) of flat tubes (7o) with wide ends (72), said widened ends (72) being in direct contact with one another and sealingly secured to each other; - a housing (3) surrounding said bundle (7) and sealingly attached to the enlarged ends (72) of the flat tubes (7o) , said casing (3) defining a sealed enclosure in which the first fluid flows between the flat tubes (70) of the bundle (7) from an inlet (37a) to an outlet (37b) of said first fluid, - an arrival box (5a) and an outlet housing (5b) of the second fluid, said housings (5a, 5b) being positioned at the ends of the beam (7) and being sealingly attached to the ends of the casing (3), said second fluid flowing inside the flat tubes (70) of the bundle (7), characterized in that the ends of the housing (3) comprise a flare (32) 20 at each end, said flare (32) forming, in cooperation with the ends of the beam (7), a fixing groove (34) in which is inserted the inlet housing (5a) or outlet housing (5b) of the second fluid. 2. heat exchanger (1) according to claim 1, characterized in that the housing (3) comprises four walls (3a, 3b, 3e, 3d) independent fixed to each other and forming said housing (3). 3. Heat exchanger (1) according to the preceding claim, characterized in that the independent walls (3a, 3b, 3e, 3d) are fixed together by brazing. 4. Heat exchanger (1) according to any one of the preceding claims, characterized in that the housing (3) is fixed by brazing to the beam (7). 5. heat exchanger (1) according to any one of the preceding claims, characterized in that the widened ends (72) of the flat tubes (7o) have a rectangular shape. 6. Heat exchanger (1) according to any one of the preceding claims, characterized in that the inlet (37a) and the outlet (37b) of the first fluid are formed on the same wall of the housing (3). 7. heat exchanger (1) according to any one of the preceding claims, characterized in that the fixing groove (34) comprises a sealing means (9). 8. Heat exchanger (1) according to any one of the preceding claims, characterized in that at least two flares (32) at each end of the housing (3) comprise locking appendices (38) folded over the housing 20 of arrival (5a) or the outlet housing (5b) of the second fluid. 9. Heat exchanger (1) according to any one of the preceding claims, characterized in that it is configured to cool the charge air of an engine in a motor vehicle. 25 A method of assembling a heat exchanger (1) for transferring heat between a first and a second fluid comprising: - a bundle (7) of flattened flat tubes (70) with extended end (72), said ends wherein the widening members (72) are in direct contact with each other and sealingly attached to each other; a housing (3); an inlet housing (5a) and an outlet housing (5b); of the second fluid, said method comprising the following steps: - formation of a flare (32) at the ends of the casing (3), - tight attachment of the beam (7) inside the casing (3) at the extended ends (72) flat tubes (70), so that the flare (32) at the ends of the housing (3), in cooperation with the ends of the beam (7), forms a fixing groove (34), and in that said housing (3) delimits a sealed enclosure in which a first fluid circulates between the flat tubes (70) of the bundle (7) from an inlet (37a) to an outlet (37b) of the first fluid, - sealing of the inlet housing (5a) and the outlet housing (5b) of the second fluid in the fixing groove (34), so that the second fluid flows through the interior of the flat tubes (70) of the bundle (7). 11. Assembly method according to claim 10, characterized in that it comprises, between the step of sealing the beam (7) flat inside the housing (3) and the step of sealing the housing to arrive (5a) and the outlet housing (5b) of the second fluid in the fixing groove (34), an additional step of placing a sealing means (9) in the fastening groove 12. The assembly method according to one of claims 10 or 11, characterized in that the formation of a flare (32) at the ends of the housing (3) is formed by stamping. 13. The assembly method according to any one of claims 10 to 12, characterized in that the housing (3) comprises four walls (3a, 3h, 3e, 3d) forming said independent housing (3) and that fixing said four portions (3a, 3h, 3e, 3d) independent is performed during the step of sealing the beam (7) inside the housing (3). 14. The assembly method according to any one of claims 10 to 13, characterized in that the step of sealing the beam (7) inside the housing (3) is carried out by soldering.