FR2815702A1 - Method for attaching reservoir to collector tube of heat exchanger comprises mechanical assembly of two components using ribs or crimps on reservoir which fit around tube, followed by welding - Google Patents

Abstract

The method for attaching a reservoir (2) to the collector tube (3) of a heat exchanger comprises mechanical assembly of the two component followed by welding. Mechanical assembly uses ribs (4a) or crimps on the reservoir which fit around the tube. Independent claims are included for: (a) a reservoir as described above, for use in the method; and (b) a collector tube for use in the method with a profiled section (6) which fits between the ribs.

Description

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METHOD FOR ASSEMBLING A TANK ON THE COLLECTOR TUBE OF A HEAT EXCHANGER, TANK AND ASSOCIATED COLLECTOR TUBE
The present invention relates to a method of assembling a reservoir on the collecting tube of a heat exchanger such as an air conditioner or a radiator, for example. It also relates to the collecting tube as well as the reservoir and their respective improvements which are used during the implementation of the assembly or connection process.

 In the automobile, heat exchangers such as air conditioners use a tank which is connected to the collecting tube, itself connected to the cooling fins. The connection of these parts must be completely sealed and manufacturers use parts coated with a layer of aluminum which they assemble before passing them to the oven in order to achieve a perfectly sealed solder between the parts. At present, several solutions are used to carry out the prior assembly of the reservoir on the collecting tube; some use riveted spacers, others use a half of a collecting tube which is fixed on a tank, one side of which forms the other half of the collecting tube.

 These various prior assembly methods used essentially in air conditioners or radiators of motor vehicles have drawbacks related to their implementation. They most often require rework operations, preliminary transverse machining or the use of additional parts which slow down production and thus increase the cost of assembly. In addition, they do not always allow obtaining a reliable assembly despite the additional cost.

 Thus, the present invention aims to solve the aforementioned drawbacks using simple means, easy to implement and inexpensive. It proposes a method of assembling a

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 tank with a collecting tube of a heat exchanger which avoids any preliminary machining or any longitudinal recovery; this process does not require the addition of additional parts and does not fundamentally modify the design of the assembled parts which thus remain easy to produce.

 According to its main characteristic, the method of assembling by welding a tank on the collecting tube of a heat exchanger consists in a main step to carry out a prior mechanical assembly of the collecting tube on the tank before welding them together in a leaktight manner in a complementary step, and is characterized in that the prior assembly is carried out by the local deformation of portions of walls or fins holding the reservoir which trap the collecting tube.

 According to an additional characteristic, the method of assembling by welding a reservoir on the collecting tube of a heat exchanger is characterized in that the local deformation of the walls is obtained by crimping in at least two places along the length of the reservoir.

 According to another characteristic of the method of assembling by welding a reservoir on the collecting tube of a heat exchanger of the invention, it is characterized in that it comprises a preliminary step which consists in setting up the collecting tube between the fins of the reservoir by means of complementary positioning means located on the tube and on the reservoir.

 Furthermore, the invention also relates to a reservoir intended to be assembled to a collecting tube by the assembly method of the invention, said reservoir being characterized in that it has a generally cylindrical shape from which extend substantially parallel two retaining fins.

 According to another characteristic of the tank, it comprises positioning means formed by a specific profile portion intended to cooperate with a profile portion of complementary shape of the collecting tube.

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 According to the preferred embodiment of the tank of the invention, its specific profile is formed by a flat area located between the two retaining fins.

 According to this embodiment of the tank, the retaining fins extend over the entire length of the tank on either side of the specific profile portion.

 Furthermore, the invention also relates to a collecting tube intended to be assembled to a reservoir by an assembly method of the invention, said tube comprising positioning means formed by a profile portion intended to cooperate with a profile portion of complementary shape of the tank.

 According to another characteristic of the collecting tube, it is in the form of a rolled and welded tube, the transverse profile of which comprises at least one flat part.

 In addition, the collecting tube is advantageously coated with an aluminum layer to obtain soldering by brazing.

 Other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings which are given only by way of nonlimiting examples.

 Figures 1 to 6 illustrate the assembly process of the invention and the improvements to the component parts.

 Figure 1 shows in perspective a heat exchanger of the invention.

 Figure 2 illustrates in perspective a collector tube and a tank assembled.

 Figures 3a, 3b, 3c and 3d illustrate in cross section the prior assembly and the soldering of the assembly method of the invention.

 Figures 4a and 4b are two views respectively from above and from the side of the tank and the collector tube assembled.

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 FIG. 5 illustrates the transverse profile of the collecting tube.

 Figure 6 shows a side view of the collecting tube.

 Figure 7 shows the transverse profile of the tank.

 The present invention relates to a method of assembling by welding a reservoir (2) on a collecting tube (3) of a heat exchanger (1). It consists in a main step of carrying out a prior mechanical assembly of the reservoir (2) on the collecting tube (3) as illustrated in FIGS. 3a to 3c, before carrying out solder welding in a complementary step illustrated in FIG. 3d. The additional step is carried out in a manner known per se by heating the assembled assembly to around 600 ° C. to melt an aluminum layer which covers at least one of the parts and thus obtain a perfectly sealed connection between them. this.

 This welding assembly process is mainly used in the field of heat exchangers (radiators, condensers of air conditioners) for the automobile, as illustrated in FIG. 1.

 According to the invention, the main step of prior mechanical assembly is carried out by the local deformation of portions of walls (4a, 4b) called fins for holding the reservoir (2) which trap the collecting tube (3) at the level deformations performed. To do this, the collecting tube (3) is positioned between the retaining fins (4a, 4b) of the reservoir (2), as shown in FIGS. 3a and 3b, and said fins are then deformed transversely according to FI on the one hand and other side of the tube (3) to come and grip it in at least two places, as illustrated in FIG. 3c. Then, the rise in temperature illustrated in FIG. 3d makes it possible to achieve soldering by melting the aluminum layer which covers at least one of the parts (2,3).

 According to the invention, the local deformation of the retaining fins (4a, 4b) is advantageously carried out in three separate locations (A, B, C) along the collecting tube (3), as shown in FIGS. 4a and 4b, said operation can be likened to a crimping of the fins on the collecting tube at three points. The local deformation of the fins is obtained by

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 example using a specific tool adapted to solicit the fins in the direction (Fl) as shown in Figure 3c. Of course, the assembly process by welding of the invention has a preliminary manufacturing step which consists in producing, on the one hand, a reservoir (2) of generally cylindrical shape from which two lateral retaining fins extend in parallel. and, on the other hand, a collecting tube (3) intended to be positioned between the two fins.

 The invention also relates to a reservoir (2) and a collecting tube (3) intended to implement the assembly method of the invention. According to the preferred embodiment of the invention, the reservoir (2) has a generally cylindrical shape from which extend two lateral retaining fins (4a, 4b) between which the collecting tube (3) is positioned. The two fins (4a, 4b) extend along generators over the entire length (L1) of the profile forming the reservoir (2); they form with the hollow cylindrical profile a single piece and thus constitute extensions of said profile.

The reservoir is advantageously made in a manner known per se from aluminum on a die.

 According to the preferred embodiment of the reservoir (2), the thickness (el) of the profile is substantially between 2 mm and 7 mm while the thickness (e2) of the fins (4a, 4b) is between 0.5 mm and 4 mm and that their height (hl) is between 2 mm and 8 mm. It goes without saying that the retaining fins (4a, 4b) might not be perfectly parallel, but be slightly divergent, to move away from each other so as to have an opening at their apex wider than the width (L3) of the collecting tube (3) which is positioned between them. This inclination of the fins could thus make it easier to introduce or place the tube (3) therebetween.

 According to a possible variant not shown, the fins for holding the tank would not be produced by two lateral longitudinal walls which extend over the entire length of the profile, but by several portions of walls arranged opposite and spaced apart along the longitudinal axis of the tank. In this way, these wall portions form clamping or crimping tabs which can be

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 positioned at the two ends of the tank and substantially in the middle of it.

 According to the invention, the collecting tube (3) and the reservoir (2) intended to implement the method have positioning means (MP) intended to facilitate the positioning of the tube between the retaining fins (4a, 4b ), on the one hand, and the exact positioning of the latter so that their communication orifices (13) come opposite, on the other hand.

These positioning means (MP) are advantageously obtained by producing on the collecting tube (3) and on the reservoir (2) portions of specific complementary profiles (5,6) intended to cooperate together.

 According to the preferred embodiment of the reservoir (2) and the collecting tube (3), their specific positioning profile is advantageously a flat area (5,6) which carries the orifices (13) through which the fluid of the exchanger circulates. .

 The flat area (5) of the reservoir is located between the retaining fins (4a, 4b) and has a width (L2) equal to the clearance close to the width (L3) of the flat part (6) of the collecting tube (3) . It extends over the entire length (all) of the profile forming the reservoir (2). The flat area (6) of the collecting tube (3) also extends over the entire length (L4) of the tube.

 It can be noted, as shown in FIG. 7, that the internal profile of the bore of the reservoir (2) is perfectly cylindrical, the flat area (5) being located only on the external face of the latter.

 According to the preferred embodiment of the collecting tube (3), the latter is rolled, then welded, to present a transverse profile comprising at least one flat part (5). However, it can, as shown in Figure 5, have three flat faces (5,7a, 7b) and a rounded face (8). It further comprises internal transverse walls (15) crimped to separate its enclosure into several compartments. Cooling fins (9a, 9b, 9c ...) are intended to be positioned in lateral orifices (los, ob ...) located on one of the lateral faces (7a, 7b), and extending slightly in the rounding (8). It is important to note that only the collecting tube has an aluminum coating, said

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 coating covering the entire collecting tube (3) to allow a tight seal to be obtained with the reservoir (2) by brazing.

 It can be noted that the tank (2) does not require an aluminum coating like the collecting tube (3). In addition, the reservoir (2) and the collecting tube (3) have connection orifices (13) intended to allow communication between the enclosure of the reservoir and that of the collecting tube in order to allow the coolant to circulate. heat exchanger (1). When positioning the collecting tube (3) between the retaining fins (4a, 4b), the complementary planar zones (5,6) come into abutment against one another and the respective connection orifices (13) come into contact look at each other thanks to the longitudinal adjustment of the collecting tube (3) on the tank (2), their lengths (L1, L4) being identical: the prior mechanical assembly is then carried out by urging the retaining fins ( 4a, 4b) of the reservoir towards one another using a tool adapted to grip the collecting tube. This stress is advantageously carried out at the two ends (A, B) of the assembly and can also be carried out in other places to reinforce the strength of the prior mechanical assembly.

 It may be noted that the bore of the reservoir has at one of its ends a thread (11) for receiving a plug, not shown, as well as an internal shoulder acting as a stop.

 Of course, the invention is not limited to the embodiments described and shown by way of examples, but it also includes all the technical equivalents and their combinations.

Claims (10)

 1. Method of assembling by welding a tank (2) on the collecting tube (3) of a heat exchanger (1) consisting in a main step to carry out a prior mechanical assembly of the collecting tube on the tank before them weld together tightly in a complementary step, characterized in that the prior assembly is carried out by the local deformation of portions of walls (4a, 4b) or fins holding the reservoir (2) which trap the collecting tube (3 ). 2. Method of assembling by welding a reservoir (2) on the collecting tube (3) of a heat exchanger (1) according to claim 1, characterized in that the local deformation of the walls is obtained by crimping in at minus two places (A, B) along the length of the tank (2). 3. Method of assembling by welding a reservoir (2) on the collecting tube (3) of a heat exchanger (1) according to any one of the preceding claims, characterized in that it comprises a preliminary step which consists in placing the collecting tube (3) between the fins (4a, 4b) of the reservoir (2) by means of complementary positioning means (MP, 5, 6) located on the tube (3) and on the reservoir. 4. Tank intended to be assembled to a collecting tube (3) by an assembly process according to any one of the preceding claims, characterized in that it has a generally cylindrical shape from which two fins of substantially parallel extend maintenance (4a, 4b). 5. Tank according to claim 4, characterized in that it comprises positioning means (MP) formed by a specific profile portion (5) intended to cooperate with a profile portion (6) of complementary shape to the collecting tube. <Desc / Clms Page number 9>  6. Tank according to claim 5, characterized in that its specific profile is formed by a flat area (5) located between the two retaining fins.  7. Tank according to claim 5 or 6, characterized in that the holding fins (4a, 4b) extend over the entire length of the tank (2) on either side of the specific profile portion (5) .  8. Manifold tube (3) intended to be assembled to a reservoir (2) by an assembly method according to any one of claims 1 to 3, characterized in that it comprises positioning means formed by a portion of profile (6) intended to cooperate with a profile portion (5) of complementary shape to the reservoir (2).  9. Manifold tube (3) according to claim 8, characterized in that it is in the form of a rolled and welded tube whose transverse profile comprises at least one planar part (5).  10. Collector tube (3) according to claim 8 or 9, characterized in that it is coated with a layer of aluminum.