EP1176378B1 - Process for manufacturing a fin for a heat exchanger, fins according to said process and heat exchange module with such fins - Google Patents

Abstract

The method for making the shared cooling fins for a heat exchanger comprising two pipes for circulating cooling liquid and which consist of a metal strip divided into two heat exchange zones (18, 20) by longitudinal apertures comprises forming a series of longitudinal slits (22) in a metal strip (14). These are then enlarged to form the apertures. An Independent claim is included for a heat exchanger module containing the fins.

Description

The invention relates to heat exchangers, in particular for motor vehicles.

It relates more particularly to a manufacturing process of a fin for a heat exchange module which comprises at least two heat exchangers comprising each a body provided with fluid circulation tubes and further comprising cooling fins common to the exchangers, the fin consisting of a metal strip having a width divided into at least two heat exchange zones by at least one set of lights longitudinally spaced from each other. An example of this type is described in EP-A1-0431917

There are two main technologies for achieving heat exchangers for motor vehicles. According to one first technology, the constituent parts of the heat exchanger are assembled and then joined in a single operation of brazing. For this type of exchanger, the fins are formed corrugated inserts arranged between the tubes and parallel to these. According to another technology, the constituent parts of the exchanger are assembled exclusively by mechanical means such as crimping. This type of exchanger has fine and flat fins arranged perpendicular to the circulation tubes.

Generally, a motor vehicle has several heat exchangers, for example a cooling radiator of the engine, a condenser part of a circuit air conditioning, and possibly an air cooler supercharger or oil cooler. It is advantageous to group these exchangers in a single module that can be mounted in the vehicle in one operation.

Such exchange modules then advantageously comprise common fins and are crossed by the same flow air. The fact that the fins are common to different exchangers simplifies manufacturing and also allows for make the whole thing more compact.

Since the different exchangers that make up the module operate at different temperatures it is necessary to define, in these common fins, heat exchange zones specific to each exchanger. AT this end, it is known to practice series of lights separated by fine intervals of material in order to avoid thermal bridges between the different exchange zones of heat of the fin. According to the technique currently used, these lights are made by removing material, for example by perforation punching. This process has the disadvantage of generating material falls difficult to manage in production and very expensive.

The subject of the invention is precisely a manufacturing process of fins for a heat exchange module comprising several exchangers that suppresses the production of falls of matter.

• on pratique au moins une série de fentes longitudinales espacées les unes des autres dans la bande métallique ; et
• on élargit les fentes longitudinales pour former une série de lumières espacées les unes des autres.

This result is obtained according to the invention by the fact that:

• at least one series of longitudinal slots spaced apart from one another in the metal strip; and
• the longitudinal slots are enlarged to form a series of spaced apart lights.

Thanks to this process, material falls are suppressed since the lights are not obtained by removal of matter but by making a slit that is next enlarged to constitute the light. Because of this, the need to handle falls of material is removed. In addition, the fin can be made from a metal strip of smaller width, which also leads to a reduction of its manufacturing cost.

According to a first variant of the process, stampings are formed between the longitudinal slots and flattened these stampings to widen the slits and form the lights.

According to another variant of the process, at least one series of slots divided into two spaced parallel rows one from the other in the direction of the width of the band metal, and the metal strip is stretched in the direction of its width to widen the slits and form the lights.

Preferably, the slots of the two rows overlap partially in the longitudinal direction of the metal strip.

The invention also relates to a fin for a module heat exchanger comprising at least two heat exchangers each having a body provided with circulation tubes fluid and further comprising fins of cooling common exchangers. This wing is obtained by the process of the invention.

Finally, the invention relates to a heat exchange module comprising at least two heat exchangers comprising each a body provided with fluid circulation tubes and further comprising cooling fins common to the interchanges. The fins are obtained by method of the invention.

Other features and advantages of the invention will appear again on reading the following description examples of embodiments given for illustrative purposes in reference to the appended figures.

• la figure 1 est une vue partielle en perspective d'un module d'échange de chaleur constitué de deux échangeurs associés ;
• la figure 2 est une vue partielle de dessus d'une bande métallique pour la réalisation d'une ailette par le procédé de l'invention ;
• la figure 3A est une vue partielle en perspective d'un embouti formé entre les fentes de la bande métallique représentée sur la figure 2 ;
• la figure 3B est une vue partielle en perspective correspondant à la figure 3A, après aplatissement de l'embouti ;
• la figure 4 est une vue partielle de dessus de la bande métallique représentée sur les figures 1 et 2 à une étape ultérieure du procédé de l'invention ;
• la figure 5 est une vue en perspective d'une ailette obtenue à partir de la bande métallique représentée sur la figure 4 ;
• la figure 6 est une vue à échelle agrandie du détail VI de la figure 5 ;
• la figure 7 est une vue partielle de dessus, similaire à la figure 2, d'une bande métallique pour la réalisation d'une ailette selon une variante du procédé de l'invention ;
• la figure 8 est une vue partielle de dessus de la bande métallique représentée sur la figure 7 à une étape ultérieure du procédé de l'invention ;
• la figure 9 est une vue en perspective d'une ailette obtenue à partir de la bande métallique représentée sur la figure 8 ; et
• la figure 10 est une vue à échelle agrandie du détail X de la figure 9.

In these figures:

• Figure 1 is a partial perspective view of a heat exchange module consisting of two associated exchangers;
• Figure 2 is a partial top view of a metal strip for producing a fin by the method of the invention;
• Figure 3A is a partial perspective view of a stamp formed between the slots of the metal strip shown in Figure 2;
• Figure 3B is a partial perspective view corresponding to Figure 3A, after flattening of the stamping;
• Figure 4 is a partial top view of the metal strip shown in Figures 1 and 2 at a subsequent step of the method of the invention;
• Figure 5 is a perspective view of a fin obtained from the metal strip shown in Figure 4;
• Figure 6 is an enlarged view of detail VI of Figure 5;
• Figure 7 is a partial top view, similar to Figure 2, of a metal strip for producing a fin according to a variant of the method of the invention;
• Figure 8 is a partial top view of the metal strip shown in Figure 7 at a later stage of the process of the invention;
• Figure 9 is a perspective view of a fin obtained from the metal band shown in Figure 8; and
• FIG. 10 is an enlarged view of the detail X of FIG. 9.

The heat exchange module shown in FIG. consisting of a radiator 1 for cooling a motor of motor vehicle and an air conditioning condenser 2, these two exchangers are generally planar.

The radiator 1 consists in a known manner of a beam of vertical fluid circulation tubes 5 mounted between two collector boxes 6 (only one box has been shown), the collector boxes 6 being arranged along two parallel sides of the tube bundle and provided with tubing 8 inlet and outlet of the cooling fluid.

The condenser 2 also consists of a beam of vertical fluid circulation tubes 10 mounted between two collector boxes 12 (only one box has been shown), the collector boxes being arranged along two sides beams of the beam and provided with inlet and outlet coolant outlet (not shown).

The fins of the heat exchange module are common to two exchangers. In one embodiment they are constituted by spacers 30 of corrugated sheet disposed between the tubes 5 and 10.

The collector box 6 of the exchanger 1 (FIG. formed from metal sheets, advantageously aluminum, shaped by conventional cutting and stamping. It has a bottom 32 which is generally flat and elongated rectangular. This background 32 is intended to constitute the collector plate, again called "plate with holes", of the collector box 6. It comprises for this purpose a plurality of spaced holes 34 of elongate form for receiving the tubes 5 of the exchanger 1. The manifold box 6 further comprises two flanks side 36 folded vis-à-vis which are usually plans and parallel to each other. These flanks 36 are connected substantially perpendicular to the bottom 32 by two lines of folding which are parallel to each other. The tubing 8 is arranged in one of the lateral flanks 36.

The collector box 6 is closed by a metal strip 37 of given width which has parallel generatrices. This strap 37 can come to fit between the flanks lateral 36 of the collector box 6 to form a set ready to be brazed at the same time as the tubing 8.

The manifold 12 of exchanger 2 has the shape general of an elongated cylinder provided with perforations 39 intended to receive the tubes 10 of the exchanger.

FIG. 2 shows a strip of metal sheet 14 of great length for the realization of a fin 30 for a heat module such as the one shown in Figure 1. The metal strip 14 has a width L1 which is divided into a first heat exchange zone 18 and a second heat exchange zone 20 by a series of longitudinal slots 22 made in the sheet metal strip 14. The sheet metal strip 14 is divided into as many exchange zones of heat that there are exchangers in the module. Given that the module of FIG. 1 comprises two exchangers, know the radiator 1 and the condenser 2, the band 14 is divided into two heat exchange zones 18 and 20. In a another example embodiment, the heat exchange module could include three exchangers, for example a cooler charge air in addition to the radiator 1 and the condenser 2. In this case the metal strip 14 would divided into three heat exchange zones by two series longitudinal slots 22.

It should also be noted that the widths of zones 18 and 20 are not necessarily equal. The width of each of these areas corresponds to the width of the circulation tubes of fluid of each of the exchangers. If the tubes of the radiator 1 are longer than the condenser 2 tubes, the zone heat exchange 18 intended to establish an exchange of heat with the tubes of the radiator 1 will be longer than the heat exchange zone 20 for establishing an exchange of heat with the condenser tubes 2.

The slots 22 do not extend the full length of the 14. On the contrary, they are spaced the from each other by areas in which there is still material. In the exemplary embodiment shown on the FIG. 2 shows stampings 24 (see FIG. 3A) in FIG. these areas of matter. Conversely, it is possible to train first the embossed, then to realize the slots 22 between stampings. The stampings 24 are then flattened so to space apart the lips of the slots 22 and to forming lights 26 separated from each other by tabs 28, as shown in FIGS. 3B and 4. It will be noted that, unlike the method of the prior art, lights 26 were not made by abduction of material but by an enlargement of the strip of sheet metal 14 in the direction of its width. The latter thus presents a width L2 very slightly greater than its initial width L1, this width increase corresponding to the width lights 26.

In a next step of the process, the sheet metal strip 14 is corrugated in a known manner so as to form an interlayer corrugated 30 as shown in Figure 5. This spacer is divided into two heat exchange zones 18 and 20 by the lights 26 which are interrupted at regular intervals by the metal tabs 28 which make it possible to ensure mechanical strength of the interlayer.

This avoids a thermal bridge between the trading zones 18 and 20, the heat exchange can not be done only by the metal tabs 28 whose length is very reduced compared to the entire length of tab.

FIG. 7 shows a divided strip of sheet metal 32 in two heat exchange zones 18 and 20 by a series of longitudinal slots 22. In this variant, the slots 22 are not arranged in the extension of one another, as in the variant of Figures 2 to 6, but distributed in two parallel rows spaced apart from one another in the width direction of the strip 32. In addition, the slots 22 belonging to each of the two rows overlap partially at each of their ends. They delimit thus, between these ends, thin tabs 34. In a next step of the method, the strip 32 is stretched in the direction of its width L1 in a series of pebbles producing a spacing of the two exchange surfaces 18 and 20 and therefore a spacing of the lips of the slits 22. It As a result, the band then has a greater width L2 at L1.

Thus lights 26 extending longitudinally are formed and shifted alternately left and right one by relationship to each other and separated from each other by sheet metal strips 34. The sheet metal strip 32 is then corrugated so as to achieve in known manner a spacer corrugated 38 as shown in Figure 9.

Tab 38 is divided into two exchange zones of heat 18 and 20 separated from each other by the lights 25 interrupted at regular intervals by the tabs of sheet 34 arranged obliquely with respect to the longitudinal axis of the sheet metal strip 32, as can be seen on the Figure 10. This avoids, as far as possible, that a thermal bridge be established between the exchange zones of heat 18 and 20. Note that in this embodiment also, the lights 26 are obtained without removal of matter, which is a considerable advantage because it avoids having to handle such falls during manufacture of tab 38.

With reference to FIGS. 1 to 10, a module is described heat exchanger comprising brazed type exchangers. It goes without saying that the invention also applies to heat exchangers crimp type, mechanically assembled. In such exchangers, the fins are constituted by thin strips sheet metal arranged perpendicular to the circulation tubes fluid. In order to avoid the establishment of a bridge between the two heat exchange zones of the fins, the latter are divided, in an identical manner, in two areas by at least one series of longitudinal slots interrupted at regular intervals by tabs of way intended to ensure the mechanical strength of the fin.

The two embodiments of the method which have been described with reference to FIGS. 2 to 6 and 7 to 10 respectively apply in the same way to the achievement of such fins. Simply, the fins remain flat and we do not form them in corrugated metal strip like for a brazed type exchanger. In contrast, these fins must be perforated to allow passage of the tubes of exchangers 1 and 2.

Of course, the invention is not limited to the forms of previously described and extends to others variants.

Claims (6)

1. Process for manufacturing a fin for a heat exchange module which comprises at least two heat exchangers (1, 2) which are provided with fluid flow tubes and furthermore include cooling fins (30, 38) common to the exchangers (1, 2), the fin (30, 38) consisting of a metal strip (14, 32) having a width (L1) divided into at least two heat exchange regions (18, 20) by at least one series of longitudinal slots (26) that are spaced apart, characterized in that:

   at least one series of longitudinal slits (22) are made in the metal strip (14, 32), these slits being spaced apart; and

   the longitudinal slits (22) are enlarged in order to form a series of spaced-apart slots (26).
2. Process according to Claim 1, characterized in that embossments (24) are formed between the longitudinal slits (22) and in that these embossments (24) are flattened in order to enlarge the slits (22) and form the slots (26).
3. Process according to Claim 1, characterized in that at least one series of slits (22) are formed that are distributed in two parallel rows spaced apart in the direction of the width (L1) of the metal strip (32) and in that the metal strip (32) is elongated in the direction of its width (L1) in order to enlarge the slits (22) and form the slots (26).
4. Process according to Claim 3, characterized in that the slits (22) of the two rows partially overlap along the longitudinal direction of the metal strip (32).
5. Fin for a heat exchange module comprising at least two heat exchangers (1, 2) provided with fluid flow tubes and furthermore including cooling fins (30, 38) common to the exchangers (1, 2), characterized in that it is obtained by a process according to one of Claims 1 to 4.
6. Heat exchange module comprising at least two heat exchangers (1, 2), each comprising a body provided with fluid flow tubes and furthermore including cooling fins (30, 38) common to the two exchangers (1, 2), characterized in that the fins (30, 38) are obtained by a process according to one of Claims 1 to 4.

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