EP1176378A1 - 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 a fin for a heat exchange module which includes 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 being constituted by a metal strip having a width divided into at least two heat exchange zones by at least one set of lights longitudinal spaced from each other.

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

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

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

Since the different exchangers that constitute it module operate at different temperatures it's necessary to delimit, 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 material intervals 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 punching perforation. This disadvantage of the process is that it can cause material to fall difficult to manage in production and very expensive.

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

• 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, in accordance with the invention by the fact that:

• at least one series of longitudinal slots spaced from each other in the metal strip is made; and
• the longitudinal slots are widened to form a series of lights spaced from each other.

Thanks to this process, the scraps of material are eliminated since the lights are not obtained by removing material, but by making a slit which is then widened to constitute the light. Therefore, the need to manage falling material is removed. In addition, the fin can be made from a metal strip narrower in width, which also leads to reduction of its manufacturing cost.

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

According to another variant of the process, at least one series of slots distributed in two spaced parallel rows from each other across the width of the strip metallic, and we stretch the metallic strip in the direction of its width to widen the slits and form the lights.

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

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

Other characteristics and advantages of the invention will appear again on reading the description which follows illustrative examples given 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 the production of a fin by the method of the invention;
• Figure 3A is a partial perspective view of a stamped 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 the stamped;
• Figure 4 is a partial top view of the metal strip shown in Figures 1 and 2 at a later stage 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 method of the invention;
• Figure 9 is a perspective view of a fin obtained from the metal strip shown in Figure 8; and
• FIG. 10 is an enlarged view of detail X of FIG. 9.

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

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

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

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

The manifold 6 of the exchanger 1 (Figure 1) is formed from metal sheets, advantageously in aluminum, conformed by conventional operations of 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 "hole plate", from the manifold 6. It has for this purpose a plurality of spaced holes 34 of elongated shape intended to receive the tubes 5 of the exchanger 1. The manifold 6 further comprises two sides side 36 folded opposite which are generally flat and parallel to each other. These sides 36 are substantially connected perpendicular to the bottom 32 by two lines of folding which are parallel to each other. Tubing 8 is fitted in one of the lateral flanks 36.

The manifold 6 is closed by a metal strip 37 of given width which has parallel generators. This strip 37 can come to fit between the sides side 36 of the manifold 6 to form a set ready to be soldered together with tubing 8.

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

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

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

The slots 22 do not extend over the entire length of the metal strip 14. On the contrary, they are spaced apart from each other by areas in which there is still material. In the embodiment shown in the Figure 2, stampings 24 are practiced (see Figure 3A) in these areas of matter. Conversely, it is possible to train first the stamps, then make the slots 22 between stamped. The stampings 24 are then flattened so to space the lips of the slots 22 from one another and to form lights 26 separated from each other by sheet metal tabs 28, as shown in FIGS. 3B and 4. Note that, unlike the process of the prior art, lights 26 were not made by removal material but by a widening of the sheet metal strip 14 across its width. The latter thus presents a width L2 very slightly greater than its initial width L1, this increase in width corresponding to the width lights 26.

In a following 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 interlayer is divided into two heat exchange zones 18 and 20 by the lights 26 which are interrupted at regular intervals by the sheet metal tabs 28 which ensure the mechanical strength of the interlayer.

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

FIG. 7 shows a strip of sheet metal 32 divided 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 FIGS. 2 to 6, but distributed in two parallel rows spaced from each other in the direction of the width of the strip 32. In addition, the slots 22 belonging to each of the two overlapping rows partially at each of their ends. They demarcate thus, between these ends, thin sheet metal tongues 34. In a next step of the process, the strip 32 is stretched in the direction of its width L1 in a series of rollers producing a separation of the two exchange surfaces 18 and 20 and therefore a spacing of the lips of the slots 22. It as a result, the strip then has a width L2 greater to L1.

Lights 26 extending longitudinally are thus formed and shifted alternately left and right one by compared to each other and separated from each other by sheet metal tabs 34. The sheet metal strip 32 is then corrugated so as to form a known interlayer corrugated 38 as shown in FIG. 9.

Tab 38 is divided into two areas for the exchange of heat 18 and 20 separated from each other by lights 26 interrupted at regular intervals by the tabs of sheet 34 arranged obliquely to the longitudinal axis sheet metal strip 32, as can be seen on the figure 10. This avoids, as far as possible, a thermal bridge is 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 huge benefit because it avoids having to manage such falls during manufacturing of tab 38.

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

The two variant embodiments of the process which have been described with reference to Figures 2 to 6 and 7 to 10 respectively apply in the same way to the realization of such fins. Simply, the fins remain flat and they are not formed into a strip of corrugated iron as for a brazed type heat exchanger. However, these fins must be perforated to allow the passage of the tubes exchangers 1 and 2.

Of course, the invention is not limited to the forms of realization described above and extends to other variants.

Claims (6)

Method of manufacturing a fin for a heat exchange module which comprises at least two heat exchangers (1, 2) provided with fluid circulation tubes and further comprising cooling fins (30, 38) common to exchangers (1, 2), the fin (30, 38) being constituted by a metal strip (14, 32) having a width (L1) divided into at least two heat exchange zones (18, 20) by at minus a series of longitudinal lights (26) spaced from each other, characterized in that : at least one series of longitudinal slots (22) spaced from each other in the metal strip (14, 32) are made; and the longitudinal slots (22) are widened to form a series of slots (26) spaced apart from one another. Method according to Claim 1, characterized in that stampings (24) are formed between the longitudinal slots (22) and that these stampings (24) are flattened to widen the slots (22) and form the slots (26 ). Method according to claim 1, characterized in that at least one series of slots (22) is formed, distributed in two parallel rows spaced apart from each other in the width direction (L1) of the metal strip (32 ), and in that the metal strip (32) is stretched in the direction of its width (L1) to widen the slots (22) and form the slots (26). Method according to claim 3, characterized in that the slots (22) of the two rows partially overlap in the longitudinal direction of the metal strip (32). Fin for a heat exchange module comprising at least two heat exchangers (1, 2) provided with fluid circulation tubes and further comprising 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. Heat exchange module comprising at least two heat exchangers (1, 2) each comprising a body provided with fluid circulation tubes and further comprising cooling fins (30, 38) common to the two exchangers (1, 2 ), characterized in that the fins (30, 38) are obtained by a method according to one of claims 1 to 4.

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