EP0797066A1 - Headerbox of heat exchanger, more particularly for automotive vehicles - Google Patents

Abstract

The plate has a central section (3) with at least one row of apertures (7) to receive the ends of tubes. Each aperture (7) is made through a stamped boss (6-1, 6-2, 6-3) made from two or more in-line sections (8a - 8c) of selected dimensions. The apertures can be punched individually or in groups by dies of different dimensions along an axis (X - X) to receive tubes which are also of different dimensions in the same direction. The bosses can be shaped by dies of different dimensions in a direction (Y - Y) lying perpendicular to the line (X - X) of the apertures. Each one can have three aligned sections (8a, 8b, 8c) with three different dimensions along line (X - X) and five different dimensions along line (Y - Y).

Description

The invention relates to manifold plates, or manifolds, for heat exchangers, in particular for motor vehicles, and more particularly those which comprise in a central part at least one row of parallel holes suitable for receiving ends of tubes.

The parallel holes, the shape of which is adapted to that of the tube which must pass through them, are generally produced in stampings, by punching.

To manufacture such a collector, it is first necessary to start from a blank called a "medallion" which, in a first step, is stamped using a first tool, in order to form a plurality of parallel stamps.

In a second punching step, holes are made, one by stamping, and the shapes and dimensions of which are adapted to the cross section of tubes to be introduced. The stamping carried out in the first step can only correspond to a single type of tube, the dimensions of which are chosen.

Consequently, if it is desired to produce a heat exchanger provided with tubes of appreciably different dimensions, it is necessary to take a new blank blank for stamping, then to stamp it using a new tool stamping and finally punching it with a new punch.

There is therefore no manifold of a standard type, capable of being adapted to the dimensions of tubes of different sections.

Consequently, one of the objects of the invention is to provide a collector which does not have the drawback of the collectors of the prior art.

To this end, the invention provides a manifold for a heat exchanger of the type described in the introduction, in which each hole is made in a deep-drawn comprising at least two aligned indentations, of respective dimensions chosen, and capable of being punched individually or in combination , by punches of different characteristic dimensions in at least the alignment direction of the indentations, to allow the passage of tubes of different dimensions in at least this alignment direction.

According to another characteristic of the invention, each imprint is capable of being punched, by punches of different characteristic dimensions, in a direction perpendicular to the direction of alignment of the imprints of a stamped, to allow the passage of tubes d 'at least two different dimensions in this direction perpendicular to the alignment.

In this way, a single stamping tool makes it possible to produce stampings whose aligned imprints allow the production of holes of different sections. A single footprint will suffice to make a small hole, while two aligned and consecutive footprints will allow for example the production of a larger hole, or two smaller holes.

Preferably, at least one of the imprints of a stamped has a dimension in the direction of alignment which is different from the dimension (s) of the other (or the other) imprint (s).

In a preferred embodiment of the invention, each stamp includes three aligned indentations capable of being punched individually or in combination to allow the passage of tubes of three different dimensions in the direction of alignment, and of five different dimensions in a direction perpendicular to this direction of alignment.

Thus, starting from a standard blank, which is stamped using a single stamping tool capable of producing in a single operation a plurality of parallel stamps each comprising three aligned impressions, it is possible to produce, using punches of different shapes, at least fifteen collectors whose holes have different dimensions.

• prévoir une ébauche comportant une partie centrale plane;
• emboutir ladite partie centrale de l'ébauche de sorte qu'elle comporte une pluralité d'emboutis parallèles les uns aux autres et comprenant chacun au moins deux empreintes alignées de dimensions respectives choisies; et
• poinçonner l'une au moins des empreintes de chaque embouti de ladite pluralité d'emboutis, individuellement ou en combinaison, de sorte que l'on réalise des trous de dimensions adaptées pour autoriser le passage d'extrémités de tubes de dimensions différentes selon au moins la direction d'alignement.

The invention also provides a method of manufacturing a header plate for a heat exchanger, in particular for a motor vehicle, comprising the following steps:

• providing a blank comprising a flat central part;
• stamping said central part of the blank so that it comprises a plurality of stampings parallel to each other and each comprising at least two aligned imprints of respective dimensions chosen; and
• punching at least one of the imprints of each stamp of said plurality of stamps, individually or in combination, so that holes of suitable dimensions are made to allow the passage of tube ends of different dimensions according to at least alignment direction.

• la figure 1 illustre une vue en perspective d'une partie d'un collecteur selon l'invention dans un mode de réalisation préféré;
• la figure 2 est une coupe transversale selon la ligne II-II du collecteur de la figure 1;
• la figure 3 est une vue en coupe transversale selon la ligne III-III du collecteur de la figure 1;
• la figure 4 est une vue en coupe transversale selon la ligne IV-IV du collecteur de la figure 1; et
• la figure 5 est une vue en coupe longitudinale selon l'axe V-V du collecteur de la figure 1.

In the description which follows, given by way of example, reference is made to the appended drawings, in which:

• Figure 1 illustrates a perspective view of a portion of a manifold according to the invention in a preferred embodiment;
• Figure 2 is a cross section along line II-II of the collector of Figure 1;
• Figure 3 is a cross-sectional view along line III-III of the collector of Figure 1;
• Figure 4 is a cross-sectional view along line IV-IV of the collector of Figure 1; and
• FIG. 5 is a view in longitudinal section along the axis VV of the collector of FIG. 1.

A heat exchanger generally comprises one or two fluid boxes (not shown) into which open the ends of metal tubes 1 (see FIG. 5), and forming a bundle of tubes spaced by fins.

These tubes are generally held parallel to each other by a collector plate 2 (or collector) which also forms the cover of the fluid box.

The collector plate 2 comprises, on the one hand, a central part called "bottom", and on the other hand, over the entire periphery of its central part, a shaped peripheral edge 4, for example by folding, which delimits a groove 5 U-shaped arranged to accommodate a peripheral heel formed on the periphery of the wall forming the fluid box.

The collector plate 2 comprises, in its central part, a multiplicity of stampings or bosses 6-i (i = 1 to n, n being the total number of stampings), parallel to each other. Each pressed 6-i comprises a hole 7 (in the example illustrated in FIG. 1 only the pressed 6-3 is provided with a hole) capable of receiving one end of the tube 1.

The stampings are preferably intended to accommodate oblong tubes (also called flat tubes) having a small axis B (or width), and a large axis A (or length). Usually the tubes are positioned in the plate manifold 2 parallel to the short side, or transverse side, of the manifold plate 2. Consequently, in the following description, it will be considered that the length of a section of tube 1 (or of hole 7) corresponds to a direction substantially perpendicular to the long side (or longitudinal side) of the collector plate 2, while the width of a section of tube 1 (or hole 7) corresponds to a direction substantially perpendicular to the short side (or transverse side) of the plate collector 2.

As illustrated in Figure 3, the space between two consecutive stamps is flat.

According to the invention, each stamped part 7 is subdivided into at least two sub-stamps 8a and 8b each forming an imprint. In the example illustrated in the figures, each stamped 6-i is in fact subdivided into three sub-stamps 8a to 8c.

To make these stampings 6-i, one starts from a blank whose peripheral edges 4 surrounding the flat central part 3 preferably have already a conformation forming the U-shaped groove 5. Then by stamping using a stamping tool comprising a multiplicity of parallel stamping heads each comprising as many aligned sub-parts as necessary (three in the example illustrated), the central part 3 of the blank is stamped in order to form the multiplicity stamping 6-i each comprising as many sub-stamps (or imprints) 8 aligned as each head of the stamping tool has sub-parts.

It is clear that the number of undercuts (or cavities) subdividing a stamping depends on the total number of tubes of different sections used by a manufacturer to produce the different variants of heat exchangers that he markets.

There is then a "pre-collector" (or standard blank) which can be transformed by punching into a large number of collector plates 2 adapted to receive tubes of different sections, respectively.

For example, it is possible to produce a first type of collector 2 of which only the undercuts 8a have a hole 7 of length A1 (see FIG. 2) and of width B1 (see FIG. 5).

In the example illustrated in FIGS. 1 and 4, the hole 7 of the stamped 6-3 is made over the entire length of the three sub-stamps 8a to 8c (or indentations), so that said hole has a length A3 (see figures 2 and 4).

), ou bien différentes (si $\text{A1 ≠ A4}$

), ce qui permet, par exemple, de réaliser des échangeurs de chaleur à une seule boîte à fluide.It would obviously be possible to provide many other variants of manifold plates 2, such as for example a first variant in which the holes are made on two consecutive sub-stamps 8a and 8b, in order to accommodate tubes of length A2 (see FIG. 2), or else a second variant in which two rows of holes of length A1 and A4 are produced using, on the one hand, the undercuts 8a, and on the other hand, the combination of consecutive undercuts 8b and 8c. In the latter embodiment, it is thus possible to accommodate, in the width of a housing and consequently of a collector plate 2, two oblong tubes of substantially equal dimensions (if $\text{A1 = A4}$

), or different (if $\text{A1 ≠ A4}$

), which allows, for example, to produce heat exchangers with a single fluid box.

Just as one can play on the length of the holes 7, one can also play, according to the invention, on the width of the holes 7. Indeed, the invention also provides that the stampings 6-i, and therefore the undercuts 8, have a dimension in the direction YY perpendicular to the alignment direction XX of the undercuts, sufficient to allow the production of at least two different widths of holes (see Figure 5). Preferably, stampings 7 are wide enough to allow the production of holes of five different widths B. In the example illustrated in FIG. 5, only three different widths B1 to B3 have been materialized.

Thus, using a complete set of punches whose heads have different dimensions, it is possible, from a stamped blank according to the invention (or pre-collector), to produce a very large number of collector plates 2 suitable for accommodating tubes of different sections. This allows, on the one hand, to always have available a standard blank model (or pre-collector) ready to be punched as needed, and, on the other hand, to significantly reduce the costs of production of the plates collectors.

In addition, it is also possible, if necessary, to adapt collectors provided with holes of a first section, into collectors provided with holes of a second section greater in length and / or width than the first section.

• dans une première étape, on prévoit une ébauche comportant une partie centrale plane 3;
• dans une seconde étape, on emboutit la partie centrale 3 de l'ébauche à l'aide d'un outil d'emboutissage approprié, de sorte que cette partie centrale comporte une pluralité d'emboutis 6-i parallèles les uns aux autres et comprenant chacun au moins deux empreintes 8 (ou sous-emboutis) alignées, de dimensions respectives choisies; et
• dans une troisième étape, on poinçonne l'une au moins des empreintes 8 de chaque embouti de la pluralité d'emboutis 6-i réalisés à l'étape précédente, individuellement, ou en combinaison, de sorte que l'on réalise des trous 7 de dimensions adaptées à l'introduction de tubes 1.

In summary, to make a collecting plate according to the invention, the following steps must be carried out:

• in a first step, a blank is provided comprising a flat central part 3;
• in a second step, the central part 3 of the blank is stamped using an appropriate stamping tool, so that this central part comprises a plurality of stampings 6-i parallel to each other and comprising each at least two indentations 8 (or undercuts) aligned, of respective dimensions chosen; and
• in a third step, at least one of the indentations 8 of each stamp of the plurality of stamps 6-i made in the previous step is punched, individually or in combination, so that holes 7 are made of dimensions adapted to the introduction of tubes 1.

Once the collector plate has been produced, it only remains to introduce the tubes into the holes, then to join, by soldering or welding, the external wall of these tubes to the collector plate, at the punched imprints forming said holes.

The invention is not limited to the embodiment described above, but embraces all the variants which a person skilled in the art may develop within the scope of the claims below.

Thus, the number of under-stamps (or footprints) of the same stamp can be much greater than two, and the width of the stamps can be adapted to allow more than five different widths of holes.

Claims (6)

Collector plate for a heat exchanger, in particular for a motor vehicle, of the type comprising in a central part (3) at least one row of holes (7) suitable for receiving ends of tubes (1), characterized in that each hole (7 ) is produced in a deep-drawn (6-i) comprising at least two aligned indentations (8a-8c), of respective dimensions chosen, and capable of being punched individually or in combination, by punches of different characteristic dimensions in at least the alignment direction (XX), to allow the passage of tubes (1) of different dimensions along at least this alignment direction. Collector plate according to claim 1, characterized in that each imprint (8) is capable of being punched, by punches of different characteristic dimensions in a direction (YY) perpendicular to the alignment direction (XX) of the imprints a stamped, to allow the passage of tubes of at least two different dimensions in this direction perpendicular to the alignment. Collector plate according to one of claims 1 and 2, characterized in that at least one of the indentations (8a) has a dimension (A1) according to the direction of alignment different from the dimension (s) ( A2, A3) of the other (or the others) imprint (s) (8b, 8c). Collector plate according to one of claims 2 and 3, characterized in that each stamping (6-i) comprises three aligned indentations (8a-8c) capable of being punched individually or in combination to allow the passage of tubes (1) of three different dimensions in the direction of alignment (XX) and of five different dimensions in a direction (YY) perpendicular to this direction of alignment. Method for manufacturing a header plate for a heat exchanger, in particular for a motor vehicle, characterized in that it comprises the following steps: - provide a blank with a flat central part (3); - stamping said central part (3) of said blank so that it comprises a plurality of stampings (6-i) parallel to each other and each comprising at least two indentations (8a-8c) aligned with respective dimensions chosen; - punching at least one of the indentations (8) of each stamp (6) of said plurality of stamps, individually or in combination, so that holes (7) of suitable dimensions are made to allow the passage of 'ends of tubes (1) of different dimensions according to at least the alignment direction (XX). Method according to claim 5, characterized in that in the stamping step the respective dimensions of the indentations are chosen so that holes can be made whose dimension in the direction (YY) perpendicular to the direction of alignment (XX) can take at least two different values.

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