FR2935912A1 - Lateral flange and collecting plate assembling method for supercharge air cooler of motor vehicle, involves forming assembling hole in tab of collecting plate, and pushing punch into assembling hole through tab of lateral flange - Google Patents

Abstract

The method involves forming an assembling hole e.g. cylindrical shaped through hole, in a tab (320) of a piece i.e. collecting plate (300). The tab of the collecting plate and a tab (220) of another piece i.e. lateral flange (200) are placed in a side-by-side manner between a punch (410) and a smooth anvil (420), where the tab of the collecting plate is placed against the smooth anvil. The punch is pushed into the assembling hole through the tab of the lateral flange. Independent claims are also included for the following: (1) a method for brazing a piece i.e. lateral flange, and another piece i.e. collecting plate, of a heat exchanger (2) a heat exchanger comprising mechanical connection units.

Description

2935912 METHOD FOR ASSEMBLING AND BRAZING TWO PARTS HAVING ASSEMBLY ELEMENTS

The present invention relates to a method of assembling two parts each provided with at least one connecting element and wherein the connecting element is at least one tongue carried by one of said parts.

The invention finds a particularly advantageous application in the field of heat exchangers and more particularly that of charge air coolers in motor vehicles with turbocharged engines. When a motor vehicle is equipped with a turbocharged engine, it is preferable to cool the charge air between the compressor outlet and the inlet of the intake air distributor, so as to increase the density of the engine. air entering the combustion chambers of the engine. A charge air cooler generally consists of a set of flat aluminum tubes through which the charge air is circulated to be cooled. These tubes are arranged to constitute a stack, or beam, in which two consecutive tubes are separated by an interval forming a space intended to allow the circulation of cooling air through the beam in a direction transverse to that of the flow. of charge air. The thermal contact between the cooling air and the tubes is provided by aluminum spacers placed in the gap between the tubes. These spacers may have the accordion shape whose ends folds are brazed to the tubes. The cooling of the charge air inside the tubes is favored by the presence of obstacles to the circulation of the air, called disrupters, whose shape is, for example, similar to that of the spacers. The cooling tubes are held in position relative to each other by means of two so-called collector plates, or collectors, arranged at each end of the bundle. These collecting plates 2935912 have the general shape of a grid consisting of a frame and a plurality of spacers defining parallel openings through which are disposed the ends of the tubes. Furthermore, the bundle of tubes receives two lateral cheeks, in the form of plates parallel to the tubes, intended to protect the end inserts, if not accessible from the outside, and to provide the chiller with the rigidity and the mechanical contacts necessary for brazing quality. It is known heat exchangers in which the side cheeks are not connected to the collector plates. The disadvantage of this solution is that, when pressure variations occur, the tubes can not withstand the corresponding variations in curvature experienced by the collector plates and, therefore, break at the junction with the collector plates. Therefore, other embodiments in which the side cheeks and the collector plates are mechanically bonded are preferred. This solution solves the aforementioned difficulties relating to pressure variations, but introduces another, namely that created by the thermal shock applied to the tubes during a rise in temperature of the charge air. In view of the general architecture of the cooler, such an increase in temperature causes the tubes to heat up before the lateral cheeks, so that they can not expand freely in the collector plates themselves held by the cheeks. , they crack at the right of the openings of the plates. This problem is solved by using side cheeks with dilatation lyre. In the context of this cheek-dilated solution, there are several techniques for making the mechanical connection between the two chiller parts consisting of a lateral cheek, on the one hand, and a collector plate, on the other hand. 'somewhere else. A first technique is simply to apply the edge of the cheek against the header plate and to braze all of the two parts. However, with this assembly method, it is not possible to guarantee 100% brazing quality due to the expansions that may occur during the soldering operation. According to a second technique, the edge of the side cheek is provided with planar connecting elements in the form of tongues, or crenellations, for example, which are introduced into slots provided at the ends of the collector plate. Then, the two pieces thus assembled are brazed. By testing the tightness of the cooler, the quality of the soldering can be guaranteed at 100%, but this at the cost of the disposal of the leaky coolers because of leakage occurring between the tabs of the cheek and the slits of the plate. collecting.

Another disadvantage of this technique lies in the increase in the length of the collector plates, and therefore the overall size of the cooler, related to the realization of the slots for receiving the tabs of the side flanges.

Finally, a third technique, called crimping, consists of providing the edge of the lateral cheek and the edge of the collector plate with planar connecting elements, tongues or crenellations, to apply the tongues of the cheek to the edge. of the plate, and turn and fold the tabs of the collector plate on the tabs of the cheek. This technique, no

20 through, is free of leaks, but has the disadvantage of increasing the size of the cooler due to the extra thickness induced by the stack of tabs at each end of the collector plates.

Also, an object of the invention is to propose a method of assembling two parts each provided with at least one assembly element, which

25 would provide a non-through connection, and therefore sealed after soldering parts, while limiting the extra thicknesses responsible for increasing the size of the parts after assembly.

This object is achieved, according to the invention, because said method comprises the steps of:

Making an assembly hole in the connecting element of one of said parts, said first part, placing between a punch and a smooth anvil said connecting elements joined to one another, the assembly member of the first piece being disposed against said anvil; - pushing the punch into the assembly hole through the assembly member of the second piece. Thus, it is understood that the depression of the punch produces a deformation of the material of the connecting element of the second part by compression and hardening on the edges of the assembly hole. This transfer of material from the second part into the hole of the first part ensures a sufficient assembly of the parts making it possible to keep them in position relative to each other during the entire duration of the soldering operation. the outcome of which the two parts are definitely solidarized. In terms of size, it can be observed that the excess thickness induced by the process according to the invention is limited to the single thickness of the planar connecting element, tongue or crenel, of the second part, whereas in the crimping technique described above the excess thickness produced is equal to the sum of the thicknesses of the two assembly elements. Another advantage of the assembly method 20 according to the invention is that no protrusion or bead of material from the second part outside the assembly hole can be formed. the anvil used is smooth, unlike the method known as clinching where the anvil is profiled. It is then necessary in this case to perform an additional operation to remove the bead formed. According to one embodiment, said assembly hole is of cylindrical shape. According to another embodiment, said assembly hole is of frustoconical shape. This particular shape has the advantage of better retaining the material of the second piece in the assembly hole. The invention also relates to a process for brazing two parts of a heat exchanger, wherein said method comprises the steps of: providing each of said parts with at least one planar assembly element - Assembling said parts according to the assembly method according to the invention, - soldering said parts thus assembled. The invention further relates to a heat exchanger, characterized in that it comprises at least two brazed parts according to the soldering method according to the invention. In particular, said heat exchanger is constituted by a charge air cooler in which said parts are a side cheek and a collector plate. Finally, the invention relates to a heat exchanger comprising at least one cheek and a collector plate each provided with at least one connecting element, in which the collector plate comprises a so-called receiving part of the tubes and a surrounding peripheral edge. the receiving portion of the tubes, said peripheral edge having a so-called end portion. The end portion extends in a so-called foreground plane and is provided with the so-called assembly assembly assembly member of the header plate. The cheek comprises at least one said connecting edge to the header plate, said connecting edge to the header plate being provided with the connecting element said assembly member of the cheek and extending in a plane said second 25 plan. According to the invention, the collector plate assembly member extends from the end portion of the peripheral edge and into the first plane, and the first plane is parallel to the second plane. According to a particular embodiment, the cheek assembly element is at least partly opposite the collector plate assembly member and the two cheek joint members and of the collector plate are secured by means of mechanical connection.

One variant proposes that the mechanical connection means be of the male-female type.

According to a particular embodiment, the connecting means of the collector plate assembly member comprises a hole accommodating the connecting means of the cheek assembly member and the cheek connection means is a part of the assembly element of the cheek compressed and screwed into the hole.

The following description with reference to the accompanying drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be achieved.

Figure 1 is an exploded perspective view of a heat exchanger.

Figure 2 schematically shows a sectional view of a header plate of the heat exchanger of Figure 1 provided with a lid.

Figure 3a and 3b are side views illustrating the assembly method according to the invention.

Figure 3c is a side view of two two-piece joining members assembled in accordance with the method illustrated in Figures 3a and 3b.

Figure 3d is a side view of an assembly variant of Figure 2c. FIG. 4 is a schematic perspective view showing a side cheek and a heat exchanger collector plate assembled in accordance with the method of the invention.

In Figure 1 is shown a heat exchanger 10 of a motor vehicle. Here it is a charge air cooler 10 for turbocharged engine.

As shown in Figure 1, the exchanger of 10 is built around

A bundle 100 consisting of a stack of tubes 110 provided with disruptors 111 folded accordion, two successive tubes being separated by an interval in which are placed interlayers 121 also folded

accordion, shown schematically in Figure 1, but that can be seen in Figure 3. The charge air from the compressor of the turbocharger is introduced into the beam 100 by a pipe 11 via a box 12 d inlet for distributing incoming charge air through the different tubes 110 of the bundle. The charge air thus circulates in the tubes 110 in the direction indicated by the arrow F1 of FIG. 1. After passing through the bundle 100, the cooled supercharging air is collected by an outlet box 13 and directed towards the motor admission by tubing, not shown. The heat exchanger 10 of FIG. 1 is a supercharging air cooler known as air cooling, the cooling of the charge air being carried out by the circulation of cooling air through the spacers 121 in the direction indicated by arrow F2 in Figure 1, perpendicular to the direction F1. It can be seen in FIG. 1, as well as in FIG. 3, that the heat exchange bundle has at its ends lateral cheeks 200. By lateral cheek 200 is meant a piece providing a connection between the two collecting boxes 12 and 13 of the heat exchanger. This part makes it possible, for example, to prevent the manifolds from being separated from the heat exchange bundle for example under the effect of a high pressure of the charge air circulating in the tubes 110 or under the effect of vibrations. These side cheeks 200 also serve to protect the heat exchange bundle 100, and especially the spacers 121 thereof. Here, the flange 200 comprises at least one said connecting edge to the collector plate 201 or 202. The connecting edge to the collector plate 201 or 202 is provided with at least one assembly element 220 called an assembly element 220 of the cheek. Here, the connecting element 220 extends in a plane called second plane. The tubes 110 of the bundle 100 are assembled at their ends by means of two collector plates 300 having openings 310 into which the ends of the tubes 110 are introduced.

In other words, the header plate 300 includes a so-called tube receiving portion and a peripheral edge surrounding the tube receiving portion.

The header plate 300 has a substantially rectangular shape with two so-called large sides 510 and 520 and two so-called small sides 301 and 302, the two so-called small sides will be referred to as end edges 301 and 302.

As more particularly visible in Figure 2, the peripheral edge further comprises a so-called receiving groove 530 for receiving a seal 535 and a portion of a cover called cover foot 536. This throat

Here, there is a U-shape throughout the periphery of the header plate 300. The shape of the groove can be seen as a U-shaped three-sided structure with a base 540 extending in a parallel plane. to the general extension plane of the header plate 300 and two wings 550 and 560. Here, the two wings 550 and 560 are perpendicular to said general extension plane 15 of the header plate.

The first wing 550 connects the base of the groove to the part of the receiving part of the tubes. In other words, it is the part of the receiving groove closest to the openings 310 for the passage of the tubes 110.

The second wing 560 is, for its part, the part of the throat of

20 receiving the farthest from the openings 310 for the passage of the tubes 110. Here, the second wing is still called end portion 560 and extends in a plane called said foreground. The end portion is further provided with an assembly member 320. In this embodiment, the connecting member 320 of the header plate 300 extends from the

End 560 and in the first plane. In other words, the connecting element 320 of the header plate 300 extends in the extension of the end portion 560 of the peripheral edge and only in the same plane as the latter.

It will be noted that here the first plane is parallel to the second plane.

In other words, here, the heat exchanger 10 comprises at least one cheek 200 and a collector plate 300 each provided with at least one assembly element 220, 320. According to the embodiment illustrated here, the connecting elements 220, 320 are a tongue.

In a flange architecture related to the collector plates, a mechanical connection is made between the side flanges 200 and the collector plates 300, with the advantage mentioned above of allowing the tubes to withstand the pressure variations of the charge air.

The cooler 10 thus assembled is then placed in a brazing furnace so as to permanently secure the various constituents of the cooler together by brazing.

We will now describe how a side cheek 200 is assembled before brazing to a header plate 300 according to the invention.

As shown in FIGS. 3a to 3c, the lateral cheek 200 is provided at each connecting edge with the collector plate 201, 202 of at least one element

220 assembly, here of planar general shape, such as a tongue or a crenel.

Similarly, the header plate 300 is provided at each end edge 301, 302 of at least one assembly element 320, also here planar, through which is formed a hole 321 assembly.

The two assembly elements 220, 320 are then placed facing each other and, placed side by side, between a punch 410 and a smooth anvil 420, the assembly element 320 bearing the assembly hole 321 being disposed against the anvil 420.

In other words, the connecting element 220 of the flange 20) is at least partly opposite the assembly element 320 of the collector plate 300.

The punch 410 is then pushed into the hole 321 through the material of the assembly member 220, which is then compressed and screwed into the hole 321, as shown in Figure 3c. In other words, both

Assembly elements 220 and 320 respectively: the cheek and the collector plate are secured by mechanical connection means, said mechanical connection means being of the male-female type.

In this way, an assembly of the two elements 220, 320 is obtained which is sufficient to hold the two parts 200, 300 against each other during the brazing period. Because the anvil 420 is smooth, and not profiled as for assembly by the conventional clinching method, no material overshoot, such as a bead, can be formed. This avoids having to perform an additional recovery operation to remove the bead formed. The assembly of the pieces is thus obtained in a single operation. Figure 4 illustrates an example of practical embodiment showing tongues 220, 320 assembled according to the method of the invention. Of course, the assembly hole can be made in one or the other of the assembly elements, the choice of the element 320 made in the figures is not limiting. The assembly hole 321 shown in Figures 3a to 3c is cylindrical. It may be advantageous, however, to use a frustoconical hole 321 ', as shown in Figure 3d, for better retention of the material of the element 220 in the assembly hole. In other words, the connection means of the connecting element 320 of the collecting plate 300 comprises a hole 321 accommodating the connection means of the connecting element 220 of the cheek 200 and the cheek connection means 200 is a part of the connecting element 220 of the cheek 200 compressed and screwed into the hole 321. Similarly, instead of making a hole 321 through, as in Figures 3a to 3c, one could just as well make a blind assembly hole.

Claims (9)

REVENDICATIONS1. Method for assembling two pieces (200, 300) each provided with at least one assembly element (220, 320), said element (220, 320) being at least one tongue (220, 320) carried by one ( said parts (200, 300), characterized in that said method comprises the steps of: - making a hole (321; 321 ') for assembly in the assembly element (320) to a (300) said pieces, said first piece, - placing between a punch (410) and a smooth anvil (420) said assembly elements (220, 320) contiguous to each other, the connecting element (320) with the first piece (300) being disposed against said anvil (420), - pressing the punch (410) into the assembly hole (321; 321 ') through the assembly member (220) of the second piece (200). 2. Method according to claim 1, wherein said hole (321) assembly is cylindrical. 20 The method of any one of claims 1 or 2, wherein said assembly hole (321; 321 ') is a through hole. 4. A process for brazing two pieces (200, 300) of a heat exchanger (10), characterized in that said method comprises the steps of: - providing each of said pieces with at least one element (220 320), - assembling said pieces (200, 300) according to the assembly method according to any one of claims 1 to 3, soldering said pieces (200, 300) thus assembled. 5. heat exchanger (10), characterized in that it comprises at least two parts (200, 300) brazed according to the soldering method according to claim 4. 6. Heat exchanger comprising at least one flange (200) and a collector plate (300) each provided with at least one assembly element (220, 320), said collector plate (300) comprising a so-called receiving portion of tubes and a peripheral edge (301, 302) surrounding said tube receiving part, said peripheral edge including a so-called end portion (560) extending in a plane called said first plane and being provided with said connecting element ( 320) and said cheek having at least one said connecting edge to the header plate (201, 202), said connecting edge to the header plate (201, 202) being provided with said connecting member (220) said element d assembly (220) of the cheek, said connecting element (220) extending in a so-called second plane plane, characterized in that said connecting element (320) of said collector plate (300) extends to from the end portion (560) of said peripheral edge and ns said first plane and in that said first plane is parallel to said second plane. 20 7. heat exchanger according to the preceding claim, wherein said connecting element (220) of the cheek (200) is at least partly opposite said connecting element (320) of the header plate ( 300) and wherein said two assembly members of the cheek and the collector plate (220, 320) are secured by mechanical connecting means. 8. Heat exchanger according to the preceding claim wherein said mechanical connection means are of the male-female type. 30 9. Heat exchanger of the preceding claim, wherein said connecting means of said connecting element (320) of the header plate (300) comprises a hole (321, 321 ') accommodating said connecting means of said connecting element. (220) of the cheek (200) and wherein said cheek connection means (200) is a portion of said assembly member (220) of the cheek (200) compressed and screwed into said hole (321, 321 '). ).