MXPA97001278A - Heat exchanger with welded fluid box, especially for automobi vehicles - Google Patents

Abstract

The invention relates to a heat exchanger of the type with welded fluid box, the heat exchanger comprises a collector plate (10) provided with a bottom (12) suitable to be connected to a tube bu (28), as well as a fluid box (38) terminated in a peripheral edge (36), suitable for coupling in a peripheral flange (14) of the collector plate, the bottom (12) comprising a plurality of recessed projections (32), arranged separately and in the surroundings of the peripheral flange (14) to ensure that the contact of said peripheral edge (14) and the peripheral flange (36) is maintained for connection by welding have application in heat exchangers for motor vehicles

Description

HEAT EXCHANGER WITH WELDED FLUID CASE, ESPECIALLY FOR VEHICLES AUTOMOVILES The invention relates to a heat exchanger with welded fluid box, especially for motor vehicles. More particularly, it relates to a heat exchanger of the type comprising a manifold plate provided with a suitable bottom to be connected to a tube az, as well as to a finished fluid case with a peripheral edge suitable for connecting it to a peripheral rim of the collector plate, in order to join them by welding. Numerous heat exchangers of this type are already known, whose constituent elements are usually formed of aluminum or aluminum-based alloys, and are assembled together by welding by baking in a suitable furnace. One of the problems that arise in the manufacture of said heat exchangers is that of obtaining a close contact between the edge of the fluid box and the flange of the collector plate to allow a tight connection by welding, without the risk of creating leaks As the welding is generally provided by a thin application, provided on the collector plate and / or the fluid box, it is necessary that the edge of the fluid box and the flange of the collector plate are in surface contact throughout the periphery. According to a known solution, the collecting plate is provided with a recessed throat in which the edge of the fluid box is coupled. Said solution facilitates the obtaining of a reduced set, suitable to guarantee a sealed welding between the fluid box and the collector plate, and those deformations of any type that are present in the fluid case before its introduction in the collector plate, or those deformations caused by heating the welding temperature. One of the drawbacks of this known solution lies in the difficulty of embedding a sufficiently narrow throat to correctly maintain the edge of the fluid box and in the accumulation of the collecting plate, both in the direction of the depth and in the direction of the height. Another known solution consists in using a collector plate in the form of a tray, in which the edge of the fluid box is coupled. However, this solution does not make it possible to guarantee that a narrow welding set is maintained between the edge of the fluid box and the flange of the collector plate. Additionally, it is known, by FR-A-2 712 384, a heat exchanger of a different type, that is to say, a mechanical assembly, in which projections are provided in a collector plate to guide the edge of a water box, a so that the edge of a watertight body is compressed, without being damaged or damaged. The purpose of the projections there is to guide the edge of the water box so that it arrives to compress the edge of the sealed body in the region where the edge of the sealed body is located; that is, in a peripheral groove of the collector plate. The purpose of the invention is mainly to solve the aforementioned drawbacks. Consequently, it proposes a heat exchanger of the type defined in the introduction, in which the bottom comprises a plurality of recessed projections, arranged separately and in proximity with the peripheral rim, to ensure that contact of the peripheral edge of the rim is maintained. fluid box against the peripheral flange of the collector plate, with a view to its union by welding. In this way, when the peripheral edge of the fluid box is engaged by drawing in the peripheral rim of the collector plate, said peripheral edge is guided and maintained in contact against the rim of the collector plate, which allows to obtain a preferential assemble between the collector plate and the fluid box. As a result, an intimate surface contact between said edge and the rim is obtained, along its entire periphery, which allows to obtain a sealed union by welding. In one embodiment of the invention, each embossed projection comprises at least one generatrix extending in a direction substantially parallel to the peripheral flange of the collector plate, and which is at a distance substantially equal to, preferably greater than, the thickness of the collector plate. of the peripheral edge of the fluid box. The presence of said generatrices facilitates that the peripheral edge of the fluid box is in contact with the peripheral rim of the collector plate. In a preferred embodiment of the invention, each embossed projection is formed in the shape of a peak of generally circular cylindrical shape, with parallel generatrices. In another embodiment, each projection is formed to the shape of a dome. The invention is particularly applied to a heat exchanger of the type defined above, in which the bottom of the collector plate comprises a multiplicity of holes, each of which is surrounded by an internal protrusion to receive the end of a tube. According to the invention, the projections are advantageously provided between adjacent internal protuberances. The bottom of the collector plate of said heat exchanger usually comprises external protuberances, each arranged between two adjacent internal protuberances. According to the invention, the projections are advantageously each located on the axis of an external protrusion.

The invention is particularly applied to a heat exchanger in which the collector plate has a substantially rectangular shape and is delimited by two longitudinal sides and two transverse sides. In similar case, the projections are advantageously provided along the longitudinal sides. It is generally not necessary to provide projections along the transverse sides. According to another characteristic of the invention, the flange of the collector plate comprises an end which is locally crimped against the fluid box to guarantee a provisional retention until the moment of welding. In a preferred embodiment of the invention, the collector plate and the fluid case are both formed of aluminum or of an aluminum alloy. In the description that follows, given only by way of example, reference is made to the accompanying drawings, in which: Figure 1 is a partial top view of a collector plate of a heat exchanger according to the invention , before assembly with a fluid box. Figure 2 is a partial sectional view, taken along the line II-II of figure 1. Figure 3 is a sectional view, taken along the line III-III of figure 1, after assembling the collector plate with a box of fluid and with a bundle of tubes. Figure 4 is a detail of figure 3; and Figures 5 and 6 are views similar to those of Figures 3 and 4, for another embodiment of recessed projections. Reference is first made to FIG. 1 which partially represents, seen from above, a collector plate 10 which is to be part of a heat exchanger according to the invention. The collector plate 10 is formed of a metallic material, for example, of aluminum or of an aluminum alloy. The collector plate 10 has the shape of a typical basin and comprises a generally flat bottom 12 of rectangular shape, bordered by a peripheral rim 14, which comprises two longitudinal sides 16, parallel to each other, only one of which is visible in Figure 1. The sides 16 and 18 are joined together by the rounded portions 20, which are in the form of quarter-circles. Additionally, the collector plate 10 comprises a leg 22 extending beyond one of the transverse sides 18, for serving, for example, as a support leg. At the bottom 12 of the collector plate (FIGS. 1 and 2) there is provided a row of holes 24 of oblong shape, each intended to receive the end 26 of a tube 28 (FIGS. 3 and 4) forming part of a beam of parallel tubes. In the example, the tubes 28 are flat tubes, between which corrugated separators (not shown) are provided which form fins. Each of the holes 24 is bordered by an internal protrusion 30 of a shape homologous to that of the hole and protruding from the side of the peripheral flange 14, as can be seen in figures 2 to 4. In other words, each of the protuberances 30 is disposed on the side of the fluid box, where it will remain further. The presence of the internal protuberances 30 facilitates a better surface contact between the collector plate 10 and the tubes 28, in order to facilitate their connection by means of welding. The bottom 12 of the collector plate 10 also comprises external protuberances 31 (FIGS. 1 to 4) each arranged between two adjacent internal protuberances 30. The outer protuberances 31 are oblong in shape and directed from the side opposite the fluid box. They have substantially co or its function to strengthen the bottom of the collector plate. The bottom 12 of the collector plate comprises a plurality of recessed projections 32, arranged along two parallel lines, respectively, on the two longitudinal sides 16 of the peripheral flange 14 (Figure 1). As best seen in Figures 3 and 4, each of the projections 32 forms a protrusion extending on the same side as the flange 14., that is, on the side of the protrusion 30, therefore, on the side opposite the protrusion 31. In the embodiment of FIGS. 1 to 4, each of the projections 32 has the shape of a substantially hemispherical dome. Each of the projections 32 is disposed between two adjacent internal protrusions 30 and on the axis of an external protrusion 31. The dome bottom of each projection 32 (Figure 1) is located at a determined distance d, from the peripheral flange 14, that is, with respect to the internal face of a longitudinal side 16. This distance d is substantially equal, or preferably greater than the thickness of the peripheral edge 36 of a fluid box 38, intended to be assembled to the collector plate 10 by welding . The fluid box 38 is formed of metallic material, advantageously of aluminum or of aluminum alloy, and comprises a wall 40, provided with reinforcement ribs 42, in a U-shape, as shown in figures 2 and 3. wall 40 is joined at peripheral edge 36 by means of a hob 44 (figures 3 and 4). The peripheral edge 36 has a rectangular contour with rounded wedges corresponding to those of the peripheral edge 14 of the collector plate, with a view to its assembly by embossing, as shown in figures 3 and 4. The heat exchanger of the The invention is fabricated in the following manner: The tubes 28 and their separators (not shown) are first assembled with the collector plate 10. The fluid box 38 is then assembled with the collector plate 10. For this, the peripheral edge 36 is inserted. of the fluid box in the peripheral flange 14 of the collector plate. Because the edge 36 and the flange 14 have homologous shapes, they tightly embed one in the other. At the end of the embossing, the edge 36 of the collecting box is guided by the projections 32, which guarantees an intimate contact between the edge 36 and the flange 14, with a view to its subsequent connection by welding. To allow a provisional retention of the collector plate and the fluid box, the flange 14 is locally deformed at its end (FIG. 4) to form connection points that rest against the shoulder 44. Said connections are formed in places distributed in the periphery, preferably only at the level of the longitudinal sides. Then proceed to weld by passing the heat exchanger through an appropriate furnace, which causes the fusion of the solder alloy, which has previously been placed on the elements that make up the heat exchanger. The heat exchanger of FIGS. 5 and 6 is similar to that of FIGS. 1 to 4, except for the shape of the recessed projections formed at the bottom of the collector plate. In effect, the bottom 12 here comprises recessed projections 34, placed on the same sides as the projections 32, in the same manner as in the preceding embodiment. However, said projections 34 are each formed in the shape of a peak of generally circular cylindrical shape, with parallel generatrices. In addition, each projection 34 comprises at least one generatrix G (FIG. 6) extending in a direction substantially parallel to the peripheral flange 14 of the collector plate and located at a distance d from it corresponding to the distance d of FIG. Said in another way, this distance is substantially equal, or preferably superior, to the thickness of the peripheral edge 36 of the fluid box. It should be understood that the invention is not limited to the embodiments described above by way of example, and that it extends to other variants. Thus, it is possible to design recessed projections of different configurations, provided that they allow to guide the peripheral edge of the fluid box, in order to obtain an intimate contact with the peripheral rim of the collector plate. It is also possible to provide projections along the transverse sides of the collector plate, mainly when it is a collector plate of greater width. The invention is particularly applicable to the manufacture of heat exchangers that can be used with cooling radiators for motor vehicles.

Claims (9)

NOVELTY OF THE INVENTION CLAIMS

1. - Heat exchanger of the type comprising a collector plate (10) provided with a bottom (12) suitable for connecting with a bundle of tubes (28) as well as with a fluid case (38) terminated by a peripheral rim (36) , suitable for coupling in a peripheral flange (14) of the collector plate (10), with a view to its connection by welding; characterized in said changer because the bottom (12) comprises a plurality of recessed projections (32, 34) arranged spaced apart and in the vicinity of the peripheral flange (14) to ensure that contact of the peripheral edge (36) of the box is maintained. of fluid (38) against the peripheral flange (14) of the collector plate (10) with a view to its connection by welding.

2. Heat exchanger according to claim 1, further characterized in that each recessed projection (34) comprises at least one generatrix (G) extending in a direction substantially parallel to the peripheral rim (14) of the collector plate ( 10) and located at a distance (d) from it that is substantially equal, or preferably higher, to the thickness of the peripheral edge (36) of the fluid box (38).

3. Heat exchanger according to claim 2, further characterized in that each recessed projection (34) is a peak of generally cylindrical, circular shape, with parallel generatrices (G).

4. Heat exchanger according to claim 1, further characterized in that each recessed projection (32) is formed in the shape of a dome.

5. Heat exchanger according to any of claims 1 to 4, wherein the bottom (12) of the collector plate (10) comprises a plurality of holes (24) each surrounded by an internal protrusion (30) for receiving one end (26) of a tube (28); characterized in said changer because the projections (32, 34) are each provided between two adjacent internal protuberances (30).

6. Heat exchanger according to claim 5, in which the bottom (12) of the collector plate (10) comprises external protrusions (31) each arranged between two adjacent internal protuberances (30), characterized said changer because the projections (32, 34) are each located on the axis of an external protrusion (31).

7. Heat exchanger according to any of claims 1 to 6, wherein the peripheral rim (14) of the collector plate (10) has a general rectangular shape with two longitudinal sides (16) and two transverse sides ( 18), characterized in the changer because the projections (32, 34) are provided in the vicinity of the longitudinal sides (16).

8. - Heat exchanger according to any of claims 1 to 7, further characterized in that the peripheral flange (14) of the collector plate (10) comprises an end (46) that is locally crimped against the fluid case (38) for ensure that the collector plate (10) and the fluid box (38) are provisionally held for welding.

9. Heat exchanger according to any of claims 1 to 8, further characterized in that the collector plate (10) and the fluid case (38) are formed of aluminum or of an aluminum-based alloy.