FR2987673A1 - METHOD FOR MANUFACTURING A HEAT EXCHANGER TUBE FOR A VEHICLE, IN PARTICULAR A MOTOR VEHICLE, TUBE OBTAINED BY SAID METHOD AND HEAT EXCHANGER COMPRISING SUCH A TUBE - Google Patents

Abstract

The invention relates to a method for manufacturing a heat exchanger tube (2) for a motor vehicle, said tube (2) comprising a strip (10), folded on itself so as to define several channels (12a, 12b) of a fluid circulation, and a disruptor (14a, 14b), located within each of said channels, the method comprising a step of separating a sheet of material in one or more strip cut lines, located on either side of the at least one cutoff line, to define each disruptor (14a, 14b) of said tube (2) from one of said strips. The invention also relates to a tube obtained by said method and a heat exchanger comprising such a tube.

Description

A method of manufacturing a heat exchanger tube for a vehicle, in particular an automobile, a tube obtained by said method and a heat exchanger comprising such a tube The invention relates to a method for manufacturing a heat exchanger tube for a vehicle , especially automobile. It also relates to a tube obtained by said method and a heat exchanger comprising such a tube. It may in particular be cooling radiators, heating radiators, condensers, evaporators or charge coolers. It is known heat exchangers comprising a bundle of parallel tubes and two collectors (or manifolds) in which are connected in a fixed and sealed manner, the corresponding ends of the tubes. A fluid can thus flow through the tubes and exchange heat with an external air flow passing between the tubes. Many tube manufacturing technologies have already been proposed. Among these, it is known to make tubes by folding. More specifically, it has already been proposed tubes obtained from a thin wall which, when folded, has a cross-section in the form of flattened B, that is to say, with a base portion extending laterally by two top parts connected to said base portion by side portions or spokes. Said top portions are coplanar and parallel to the base portion and terminate in adjacent end legs, turned perpendicular to the base portion. Two longitudinal and parallel channels are thus defined on either side of the legs.

A disrupter or interlayer is or not introduced into said channels. These disrupters have, in particular, to improve the thermal performance of the heat exchanger and the mechanical strength of the tubes which must withstand not only the internal operating pressure in operation but also that imposed by the specifications. , in particular a resistance to bursting tubes that can go up to several tens of bars and even more than one hundred bars, depending on the applications. These disrupters are however not always necessary, especially if the needs in terms of heat exchange and / or resistance to internal pressure are relatively low. It may therefore be desirable to manufacture exchangers equipped with identical bent tubes, some of the exchangers being provided with disrupters and others not. A first solution is to use a common disrupter for the two channels of the tubes. Said disruptor passes below the legs of the tube and the size of said legs is adapted to absorb the thickness of the disrupter. In such a case, two bending tools are required for the tubes: a first tool making it possible to make legs having a first length for the tubes without interference and a second tool making it possible to make legs having a shorter length for the tubes with disruptors.

According to another solution, two separate spacers are used, one for each channel. One can then have a unique folding tool for both types of tubes because the size of the legs does not vary from one case to another. On the other hand, it is necessary to manage a separate manufacture of the spacers, which can be particularly complex.

More precisely, in order to have high production rates of the tubes, one solution is to introduce the spacers in parallel and continuously into the tube manufacturing tools, said spacers being simultaneously manufactured from two separate sheets of material, on separate tools. The constraint that must then be faced is to ensure a phasing of the production rates of each of the tools. The invention makes it possible to improve the situation and proposes for this purpose a method of manufacturing a heat exchanger tube for a motor vehicle, said tube comprising a strip, folded on itself so as to define several circulation channels. a fluid, and a disruptor, located within each of said channels, the method comprising a step of separating a sheet of material in one or more strip cut lines, located on either side of the or said cutoff lines, to define each disruptor of said tube from one of said bands. By providing two separate disruptors and obtaining said disrupters from the same sheet of material can thus both avoid the problems due to the differences in bending encountered in the tubes with common disrupters and the problems due to the independent manufacture of two disruptors in separate disruptor tubes. This optimizes the manufacture of the tubes.

In a first embodiment, the step of separating the sheet of material along one or more cut-off lines is a step of cutting said sheet of material. In this first embodiment, according to a first variant, said method may comprise a step of shaping said strips of material making it possible to obtain, in particular in parallel, said disrupters. In other words, the shaping step takes place after the cutting step. In a second variant, said method comprises a step of shaping said sheet of material so as to give it a disruptive form. In other words, the shaping step takes place before the cutting step. According to another embodiment, said method comprises a step of pre-forming said sheet of material, making it possible to obtain residual material links between said strips of material. According to this latter mode, the invention has the following characteristics, taken together or separately, - said method comprises a step of forming said sheet of preformed material, - the step of separating the sheet of material according to one or more cutoff lines is a step of breaking said residual bonds of said sheet of material. According to another aspect of the invention, said method comprises a step of insertion of the disturbers in parallel in each of said channels. As a variant, said method comprises: a step of partial folding of the strip defining housing zones of said disrupters; a step of introducing said disrupters into said housings; a step of completely closing the strip. The invention also relates to a tube obtained according to the method described above. According to different features that may be taken together or separately: said strip has legs joining a first wall of the tube to a second opposite wall of the tube so as to define said channels, said legs having a base formed of a bent portion of the tube; strip, - said disturbers are of corrugated shape, the said cutoff lines being located at a vertex of a ripple of said disturbers and forming a stop, said contact, - said contact edges are brazed to the strip close of said bent portion. The invention further relates to a heat exchanger comprising one or more tubes as described above. The appended figures will make it clear how the invention can be realized. In these figures, identical references designate similar elements. Figure 1 is an overview of a heat exchanger to which a tube obtained according to the method according to the present invention is intended. Figures 2a to 2d schematically show the various steps of a first embodiment of the method according to the invention, Figures 2a and 2b being top views and Figures 2c and 2d being cross sections. Figures 3a to 3d show schematically the various steps of a second embodiment of the method according to the invention, Figures 3a and 3b being top views and Figures 3c and 3d being cross sections. Figures 4a to 4e schematically show the various steps of a third embodiment of the method according to the invention, Figures 4a and 4b being top views and Figures 4c to 4e being cross sections. Figures 5a and 5b detail, for cross-sectional view, the bending of the tube according to an embodiment of the method according to the invention. Figure 6 is an enlarged view of a portion VI of Figure 5b. As illustrated in FIG. 1, the invention will find its applications in a heat exchanger 1 comprising tubes 2 forming, for example, a bundle in which said tubes 2 are parallel to each other. Each tube 2 has two longitudinal ends 2A connected in a fixed and sealed manner to manifolds 3, 4 of the exchanger for the circulation of a fluid, in particular a cooling liquid, a refrigerant, a charge air or the like. Said manifolds 3, 4 comprise, for example, a header plate and a lid defining an interior volume of the box. The tubes 2, in particular the longitudinal ends 2A of the tubes 2, open into said interior volume through orifices provided in the collector plates. The collecting plates are, for example metal, especially aluminum or aluminum alloys. The covers are, for example, plastic and crimped on the collector plates. Alternatively, the collector plates and lids are both metal, especially aluminum or aluminum alloys. To these manifold boxes 3, 4 are respectively reported flanges or inlet and outlet pipes 6. Between the tubes 2 may be arranged interlayers 7 increasing the heat exchange surface between the fluid flowing in the tubes 2 and a fluid, especially air, passing through the exchanger 1.

However, the invention relates more particularly to the tubes 2 of said exchanger and even more specifically to their manufacturing process. As illustrated in FIGS. 2a to 2d, 3a to 3d as well as 4a to 4d, the method according to the invention makes it possible to obtain tubes 2 of the type comprising a strip 10, folded on itself so as to define several channels 12a. , 12b fluid circulation, and a disrupter 14a, 14b, located inside each of said channels. Thus, according to the invention, it is placed in the configuration where the folding of the tube does not depend on the length of the legs because said tube comprises a specific disturbance 14a, 14b for each of the channels. In this way it will be possible to use the same folding tooling both for a tube provided with said interferers 14a, 14b and for a tube in which said interferers 14a, 14b are not useful. Said interferers 14a, 14b are configured, for example, to promote the heat exchange and the resistance of the tubes to the internal pressure. They are provided, in particular, over the entire axial length of the channels 12a, 12b. They present here undulations 30, in particular of the sinusoidal or crenellated type, the apices of said undulations 30 being subject to the strip 10. Said tubes 2 may in particular have a configuration in which said strip 10 has legs 16a, 16b joining a first flat wall 18 of the tube at a second flat wall 20 of the tube so as to define said channels 12a, 12b. By this is meant that the free ends of said legs 16a, 16b are in contact with said second wall 20. As is more readily apparent in Figure 6, said legs 16a, 16b have, for example, a base formed of a portion bent 17 of the strip 10 connecting them to the first flat wall 18. They are extended here against each other to finish against the second flat wall 20, in particular through their edge. They define here two channels 12a, 12b of substantially equal section. In other words, said legs 16a, 16b are located substantially along a median plane of the tubes 2. The invention can be applied in particular to B-folded tubes such as those described in the preamble.

Again according to FIGS. 2a to 2d, 3a to 3d as well as 4a to 4d, said method comprises a step, corresponding to FIGS. 2b, 3c and 4d, of separating a sheet of material 22 along one or more cut lines 24 in strips 26a, 26b, situated on either side of the at least one cut-off line 24. Said strips 26a, 26b serve to define each interferer 14a, 14b of said tubes 2.

Thanks to the invention, the disrupters 14a, 14b are thus produced from the same tooling through which said sheet of material 22 is fed, as illustrated in FIGS. 2a, 3a and 4a. The supply of said sheet of material 22 takes place, for example, continuously. The method according to the invention may further comprise a step of forming in parallel a profile of said interferers 14a, 14b, illustrated in FIGS. 2c, 3b and 4c, a step that may take place either before or after said separation step . Said steps of forming the profile of the interferers 14a, 14b and / or separation of the bands 26a, 26b are carried out, for example, continuously. As illustrated in FIGS. 2a to 2d and 3a to 3b, according to a first embodiment of the invention, the step of separating the sheet of material 22 along one or more cut-off lines 24 is a cutting step of FIG. said sheet of material 22. According to a first variant, corresponding to FIGS. 2a to 2d, the step of forming the profile of said interferers 14a, 14b is a step of shaping said strip of material 26a, 26b. In other words, the strip separation step 26a, 26b of said sheet of material 22 takes place before the step in which the undulations 30 of said interferers 14a, 14b are defined. As already mentioned above, said strips 26a, 26b are shaped, for example, in parallel. According to a second variant, corresponding to FIGS. 3a to 3d, the step of forming the profile of said interferers 14a, 14b is a step of shaping said sheet of material 22. In other words, in this variant, the corrugations 30 are formed. disruptors 14a, 14b on the sheet of material 22, before separation of said sheet of material 22. Still in other words, at the time of the strip separation, the undulations 30 of the disturbers 14a, 14b are already present. As illustrated in FIGS. 4a to 4e, according to another embodiment, the method according to the invention comprises a step of pre-forming said sheet of material 22, making it possible to obtain residual material links 32 between said strips. of material 26a, 26b, as is more particularly illustrated in Figure 4b. Said links 32 are located, for example, along the cut line or lines 24. Said pre-forming step takes place, for example, continuously. The step of forming the profile of said interferers 14a, 14b may then be a step of forming said pre-formed sheet of material 22. In this mode of implementation, as in that of FIGS. 3a to 3d, the corrugations 30 are thus formed before the separation of the sheet of material 22. Still in the embodiment of FIGS. 4a to 4e, the step separating the sheet of material 22 along the cut line or lines 24 is a step of breaking said residual links 32 of said sheet of material 22. This being so, according to a first variant, said interferers 14a, 14b are introduced, in particular in parallel, in said channels 12a, 12b, once the tube 2 folded. According to another variant, illustrated in FIGS. 5a and 5b, said method comprises a step of partially folding the strip 10 defining zones 28a, 28b for accommodating said interferers 14a, 14b, more particularly corresponding to the stage of folding of the tube represented in FIG. FIG. 5c, followed by a step of introducing, in particular in parallel, said disturbers 14a, 14b into said housings 28a, 28b. The folding of the tube then continues, according to the arrows marked 29, to arrive at a complete closing step of the strip 10, corresponding more particularly to Figure 5b. It will be noted in particular that the disrupters 14a, 14b are arranged in their housing 28a, 28b respectively at a distance from each other so as to allow the passage of legs 16a, 16b, provided preformed between said disrupters 14a , 14b. As the interest will appear below, they will be separated, for example, by a spacing substantially equal to twice the thickness of the sheet of material 22. Said insertion steps of the disrupters 14a, 14b and / or folding strips 10 take place, for example, continuously and / or simultaneously.

That is, said tube 2 is sealed, for example, by brazing, the brazing of the tubes 2 of the same exchanger taking place, in particular, simultaneously with brazing of the entire exchanger. In this regard, said strip 10 and said sheet of material 22 are, for example, aluminum or aluminum alloy.

As more particularly illustrated in FIG. 6, the at least one cut-off line is located at a peak 34 of a ripple 30 of said interferers 14a, 14b. Said vertex 34 thus forms an edge 36, referred to as a contact edge. More precisely, the apex 34 presenting the end of contact may have a flattened shape. In the embodiments of FIGS. 3a to 3d and 4a to 4e, the sheet of material 22 shaped to present the profile of the disturbers 14a, 14b comprises in this way a corrugation whose apex is provided with a larger plate 38 as the top of the other ripples. As illustrated in FIG. 6, said contact edges 36 are, for example, soldered to the strip near said bent portion 17 of the strip 10. This strengthens the resistance to the internal pressure of the tube. It may furthermore be noted that tubes having a disturbing end in said angled portion may be obtained by methods other than those mentioned above, without departing from the scope of the invention.

Claims (13)

REVENDICATIONS1. A method of manufacturing a motor vehicle heat exchanger tube (2), said tube (2) comprising a strip (10), folded on itself to define a plurality of flow channels (12a, 12b) a fluid, and a disruptor (14a, 14b), located within each of said channels, the method comprising a step of separating a sheet (22) of material along one or more cut lines (24) into strips (26a, 26b), located on either side of the at least one cutoff line (24), for defining each disruptor (14a, 14b) of said tube (2) from one of said strips (26a, 26b) ). 2. The method of claim 1 wherein the step of separating the sheet of material (22) along one or more cut lines (24) is a step of cutting said sheet of material (22). 15 3. Method according to claim 2 comprising a step of forming said strips of material (26a, 26b), for obtaining said interferers (12a, 12b). 20 4. The method of claim 3 wherein said strips (26a, 26b) are shaped in parallel. 5. The method of claim 2 comprising a step of shaping said sheet of material (22) so as to give it a disruptive form. 25 6. The method of claim 1 comprising a step of pre-forming said sheet of material (22) for obtaining residual material links (32) between said strips of material (26a, 26b). 30 7. A method according to claim 6 comprising a step of forming said pre-formed sheet of material (22). 8. The method of claim 7 wherein the step of separating the sheet of material (22) along one or more cut-off lines (24) is a step of breaking said residual links (32) of said sheet of material (22). ). 9. A method according to any one of the preceding claims comprising a step of insertion of the disturbers (14a, 14b) in parallel in each of said channels. 10. Process according to any one of claims 1 to 8 comprising: - a partial folding step of the strip (10) defining housing zones (28a, 28b) of said disturbers (14a, 14b), - an introduction step said disturbers (14a, 14b) in said housings (28a, 28b), - a step of completely closing the strip (10). 15 11. Tube (2) obtained by the process according to any one of the preceding claims The tube of claim 11 wherein said strip (10) has legs (16a, 16b) joining a first wall (18) of the tube (2) to a second (20) opposite wall of the tube (2) so that defining said channels (12a, 12b), said legs (16a, 16b) having a base formed of a bent portion (17) of the strip (10). 25 13. Tube according to claim 12 wherein said interferers (12a, 12b) are of corrugated shape, said at least one cut-off line (24) being located at an apex (34) of a corrugation (30) of said interferers. (14a, 14b) and forming a ridge (36), said contact. The tube of claim 13 wherein said contact edges (36) are soldered to the strip (10) near said bent portion (17). 15. Heat exchanger comprising one or more tubes (2) according to any one of claims 11 to 14.