FR3056731A1 - COLLECTOR PLATE, HEAT EXCHANGER AND METHOD OF MANUFACTURING THE SAME - Google Patents

Abstract

The present invention relates to a collector plate (4) of a collector box (3) intended to be disposed within a heat exchanger (1), said collector plate (4) having insertion orifices (40) for receiving tube ends (2), said orifices (40) being bordered by first collars (42i, 42e) comprising peripheral walls for encircling the wall of the ends of the tubes (2), said first collars (42i, 42e) ) forming first internal collars (42i), whose peripheral wall is intended to protrude inwardly of the collector box (3), and first external collars (42e), whose peripheral wall is intended to protrude towards the outside of the manifold (3), said first outer collars (42e) and inner (42i) being arranged alternately on the collector plate (4). The invention also relates to a heat exchanger and its associated manufacturing method.

Description

(57) The present invention relates to a manifold plate (4) of a manifold box (3) intended to be disposed within a heat exchanger (1), said manifold plate (4) having orifices (40) d insert intended to receive the ends of tubes (2), said orifices (40) being bordered by first collars (42i, 42e) comprising peripheral walls intended to encircle the wall of the ends of tubes (2), said first collars ( 42i, 42e) forming first internal collars (42i), the peripheral wall of which is intended to project towards the inside of the manifold (3), and first external collars (42e), the peripheral wall of which is intended to protruding outwards from the manifold (3), said first external (42e) and internal (42i) collars being arranged alternately on the collector plate (4).

The invention also relates to a heat exchanger and its associated manufacturing method.

ί 40

Collector plate, heat exchanger and associated manufacturing process.

The invention relates to a heat exchanger, in particular for a motor vehicle, and its manufacturing process.

It relates more particularly to a heat exchanger of the type comprising a multitude of tubes between which spacers are inserted. The tubes are generally tubes of oval or oblong section, defined by a major axis and a minor axis, and having ends introduced into the orifices of a manifold plate. The collector plates are covered with a cover so as to form a collector box. There are mainly two types of heat exchangers, mechanical heat exchangers, where the different elements forming the exchanger are mechanically fixed together, for example by crimping, and brazed heat exchangers where the different elements forming the exchanger are fixed together by brazing.

When the fixing and sealing of the tubes with the collector plates is of the mechanical type, the collector plates comprise collars projecting towards the outside of the collector boxes and generally formed by stamping, into which the tubes are inserted. Sealing is ensured by a compressible seal placed between the tubes and the collars.

However, due to the presence of these collars, the pitch between two tubes along the collector plate cannot be less than a certain limit. For example, for a header plate with a thickness of 1mm, tubes with a thickness of 3.5mm at the collars, and a joint with a thickness of 0.7mm, the minimum pitch between two tubes can only be from:

3.5+ (0.7x2) + (lx2) + 0.5 = 7.4mm.

This is due to the fact that it is necessary to have a clearance of 0.5mm between two collars due to the stamping die.

One of the aims of the present invention is therefore to at least partially remedy the drawbacks of the prior art and to propose an improved heat exchanger and its manufacturing process.

The present invention therefore relates to a collector plate of a collector box intended to be disposed within a heat exchanger, said collector plate comprising insertion orifices intended to receive ends of tubes, said orifices being bordered by first collars comprising peripheral walls intended to encircle the wall of the ends of the tubes, said first collars forming first internal collars, the peripheral wall of which is intended to project towards the inside of the manifold, and first external collars, whose peripheral wall is intended to project outwardly from the manifold, said first external and internal collars being arranged alternately on the manifold plate.

The fact that the collector plates comprise first internal collars and first external collars alternately makes it possible to have a reduced distance between two tubes and therefore a reduced tube pitch. It is thus possible to increase the number of tubes on the same collector plate and therefore to increase the number of tubes in the same tube bundle. This therefore increases the heat exchanger’s exchange surface and therefore increases its performance.

According to one aspect of the invention, the pitch between two first collars is between 5 and 7.4mm, preferably between 5.5 and 7.1mm.

The present invention also relates to a heat exchanger comprising:

° a bundle of tubes comprising a multitude of tubes arranged parallel to each other, ° two manifolds, a manifold being disposed on each side of the bundle of tubes, each manifold comprising a manifold plate according to one of the preceding claims.

According to one aspect of the invention, the heat exchanger comprises at least one compressible seal forming second internal collars against an external face of the first internal collars and second external collars against an internal face of the first external collars.

According to another aspect of the invention, the heat exchanger comprises a single seal per collector box, said seal being pressed against the internal face of the collector plate, and, at the orifices, said seal seal forms the second internal collar against the external face of the first internal collars, covers the protruding end of the wall of the first internal collars, runs along the internal face of the collector plate to join the first external collars and form the second collar external against the internal face of said first external collars.

According to another aspect of the invention, the ends of the tubes have a first flare so as to compress the second collars of the at least one seal within the first collars.

According to another aspect of the invention, the ends of the tubes inserted in the first external collars comprise a second blocking flare produced on the part of said tubes projecting from said first external collars.

The present invention also relates to a method of manufacturing a heat exchanger comprising:

° a bundle of tubes comprising a multitude of tubes arranged parallel to each other, and ° two manifolds, a manifold being disposed on each side of the bundle of tubes, each manifold comprising a manifold plate, said manifold plate comprising orifices inside which the ends of the tubes are introduced, said method comprising the following steps:

° alternating formation of the first internal collars and the first external collars of the collector plates, ° placement of at least one compressible seal so as to form second internal collars against the external face of the first internal collars and of the second external collars against the internal face of the first external collars, ° insertion of the ends of the tubes into the first internal collars and the first external collars, ° realization of a first flaring of the ends of the tubes so as to compress the at least one joint of sealing.

According to one aspect of the method according to the invention, said manufacturing method comprises an additional step of producing a second flaring blocking the ends of the tubes inserted in the first external collars.

According to another aspect of the method according to the invention, the step of alternately forming the first internal collars and the first external collars is carried out by stamping.

Other characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and nonlimiting example, and the appended drawings among which:

• Figure 1 shows a schematic representation of a heat exchanger, • Figure 2 shows a schematic presentation in perspective and in section of the header plate, • Figures 3a to 3e show schematic representations in section of the connection between tubes and the collector plate according to different stages of the manufacturing process.

Identical elements in the different figures have the same references.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the characteristics apply only to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments.

In the present description, it is possible to index certain elements or parameters, such as for example first element or second element as well as first parameter and second parameter or else first criterion and second criterion etc. In this case, it is a simple indexing to differentiate and name elements or parameters or criteria that are similar but not identical. This indexing does not imply a priority of an element, parameter or criterion over another and one can easily interchange such names without departing from the scope of this description. This indexing does not imply an order in time for example to assess such or such criteria.

FIG. 1 shows a heat exchanger 1 comprising a bundle formed by a multitude of tubes 2 inside which a first heat transfer fluid can circulate. The tubes 2 are arranged parallel to each other. Between the tubes 2 are placed spacers 6 (also called spacers) which act as a disturbance and increase the heat exchange surface with a second heat transfer fluid passing between the tubes 2. The tubes 2 have an oblong section which can be defined along two axes of different length. The tubes 2 have a width corresponding to the longest axis of the oblong shape of their section, and a thickness corresponding to the shortest axis of the oblong shape of their section.

The tubes 2 and the spacers 6 are generally made of metallic materials. The tubes 2 and the spacers 6 form the bundle and can be fixed together mechanically. In this case, the spacers 6 are also called fins. The fins are generally superimposed plates and placed perpendicular to the tubes 2. The fins have holes in which the tubes 2 are inserted and fixed. The fixing of the tubes 2 is said to be mechanical, for example by widening the tubes 2 by means of a olive of size larger than that of tubes 2 which is inserted into tubes 2 in order to increase their size, then removed. We then speak of a mechanical beam.

Conversely, the tubes 2 and the spacers 6 forming the bundle can be fixed together by brazing. In this case, the spacers 6 can be what are called spacers. These spacers are for example corrugated or crenellated strips, placed between the tubes 2 and fixed to the tubes 2 by brazing. We then speak of a brazed beam.

The heat exchanger 1 also includes two manifolds 3 (also called water boxes), a manifold 3 being disposed at each end of the tubes 2. These manifolds 3 have a manifold plate 4 and a cover 8 covering the plate manifold 4 and close the manifold 3. These manifolds 3 allow the collection and / or distribution of the first heat transfer fluid so that it circulates in the tubes 2.

The collector plate 4 makes a sealed connection between the collector box 3 and the bundle of tubes 2. The collector plate 4 can be of generally rectangular shape and include (see FIG. 2):

• an internal face 4a oriented towards the inside of the manifold 3 or coming from the face of said manifold plate 4 oriented towards the inside of the manifold 3, and • an external face oriented towards the outside of the manifold 3 or coming from the face of said collecting plate 4 oriented towards the outside of the collecting box 3.

As shown in FIG. 2, the collecting plate 4 comprises a multitude of orifices 40 having a shape corresponding to the shape of the section of the tubes 2 and suitable for receiving the ends of the tubes 2. Each orifice 40 is bordered by a first collar referenced 42i, 42 ^{e in} order to distinguish two kinds of first collar. The first collars 42i, 42e can advantageously be made integral with the collecting plate 4 and be formed by stamping.

The first collars 42i, 42e are of two kinds as illustrated in FIG. 3a:

• first internal collars 42i, the peripheral wall of which is intended to protrude towards the inside of the manifold 3, and • first external collars 42e, whose peripheral wall is intended to protrude towards the outside of the box collector 3.

The first external collars 42e and internal 42i are arranged alternately on the collector plate 4.

The connection between a first internal collar 42i and a first external collar 42e has a shoulder E. This shoulder E may in particular be due to the fact that the first collars 42i, 42e are produced by stamping. The internal face 4a of the collector plate 4 at the level of the first internal collars 42i is preferably situated on the same plane A as the external face 4b of the collector plate 4 at the level of the first external collars 42e. This makes it possible to minimize the distance between the first internal collars 42i and external 42e, which then corresponds to two thicknesses of the collector plate 4.

The fact that the collector plates 4 comprise first internal collars 42i and first external collars 42e in alternation makes it possible to have a reduced distance d (see FIG. 3 a) between two tubes 2 and therefore a reduced pitch P of tube 2 (see Figures 3c to 3d). It is thus possible to increase the number of tubes 2 on the same collector plate 4 and therefore to increase the number of tubes 2 in the same bundle of tubes.

2. This thus increases the exchange surface of the heat exchanger 1 and therefore increases its performance.

The collector plate 4 can also be extended by a peripheral groove ending in a peripheral rim 45 forming foldable tabs. The peripheral groove 44 is intended to receive the edges of the cover 8 and the peripheral edge can be folded and folded in order to fix said cover 8 on the collector plate 4.

The collector plate 4 receives at least one seal 5 (see FIGS. 3b to 3d) which can be compressed to form second internal collars 52i against the external face 4b of the first internal collars 42i and second external collars 52e against the internal face 4a of the first external collars 42nd. The second internal collars 52i are arranged and compressed between the ends of the tubes 2 and the external face 4b of the collector plate 4 at the level of the first internal collars 42i, in order to ensure the tightness of the connection between the tubes 2 and the plate manifold 4. The second external collars 52e are arranged and compressed between the ends of the tubes 2 and the internal face 4a of the collector plate 4 at the level of the first external collars 42e.

According to a first embodiment, illustrated in FIGS. 3b to 3e, the collector plate 4 comprises a single seal 5 per collector box 3. This seal 5 is pressed against the internal face 4a of the collector plate 4. At the openings 40, the seal 5 forms the second internal collar 521 against the external face 4b of the first internal collars 42i, covers the protruding end of the wall of the first internal collars 42i, runs along the internal face 4a of the collector plate 4 to join the first external collars 42e and form the second external collar 52e against the internal face 4a of said first external collars 42e.

According to a second embodiment not shown, the collector plate 4 may comprise a multitude of individual seals 5 which form second internal collars 521 and external 52e which are introduced respectively into the first internal collars 42, and external 42e, to seal between the tubes 2 and the manifold plate 4.

The use of a single seal 5 or of a multitude of individual seals 5 to make the connection between the tubes 2 and the collecting plate 4, allows a certain flexibility of the connection which can absorb the expansions and retractions related to the temperature variations which the heat exchanger 1 undergoes during operation. The connection between the tubes 2 and the collector plate 4 is therefore more resistant to these temperature variations, in particular during thermal shocks.

Thus, the heat exchanger 1 can have a pitch P between two first collars 42i, 42e and therefore between two tubes 2, between 5 and 7.4mm, preferably between 5.5 and 7.1mm.

For example, as illustrated in FIGS. 3d and 3e, for a tube 2 with a thickness of 3.5mm at the level of the first collars 42i, 42e, seals 5 with a compressed thickness of 0.7mm and with first collars 42i, 42e with a thickness of 1mm, corresponding to the thickness of the collector plate 4, it is possible to obtain a pitch P of tube 2 of:

3.5+ (0.7x2) + (lx2) = 6.9mm

For a bundle of 2 brazed tubes, where the tubes 2 can be thinner and with a thickness of the order of 2.4 mm, it is even possible to obtain a pitch P of tube 2 of:

2.4+ (0.7x2) + (lx2) = 5.8mm

As illustrated in Figures 3d and 3e, the ends of the tubes 2 may include a first flare 20 so as to compress the second collars 52i, 52e within the first collars 42i, 42e. This first flaring 20 of the ends of the tubes 2 allows compression of the seal 5 and therefore seals the connection between the tube 2 and the collector plate 4.

As shown in FIG. 3e, the ends of the tubes 2 inserted in the first external collars 42e comprise a second flaring 20 ′ for blocking produced on the part of the tubes 2 projecting from the first external collars 42e. This second flaring 20 'blocks the tubes 2 in translation and makes it possible to prevent the tubes 2 from coming out of the orifices 40 of the manifold plates 4.

This second flaring 20 ′ of the ends of the tubes 3 can be produced over the entire periphery of the end of the tubes 2, or it can be local and concern only a portion of the periphery of the end of the tubes 2.

The present invention also relates to a method for manufacturing a heat exchanger 1 as illustrated in FIGS. 3a to 3e. As described above, the heat exchanger 1 comprises:

° a bundle of tubes 2 comprising a multitude of tubes 2 arranged parallel to each other, and ° two manifolds 3, a manifold 3 being arranged on each side of the bundle of tubes 2, each manifold 3 having a manifold plate 4 , said collecting plate 4 comprising orifices 40 inside which the ends of the tubes 2 are introduced.

The manufacturing process includes the following steps:

° alternating formation of the first internal collars 42i and the first external collars 42e of the collector plates 4, for example by stamping. This step is illustrated in FIG. 3a, ° placing at least one compressible seal 5 so as to form second internal collars 521 against the external face 4b of the first internal collars 42i and second external collars 52e against the internal face 4a of the first external collars 42e. This step is illustrated in FIG. 3b, ° insertion of the ends of the tubes 2 into the first internal collars 42i and the first external collars 42e. This step is illustrated in FIG. 3c, ° making a first flaring 20 of the ends of the tubes 2 so as to compress the seal 5. This step is illustrated in FIG. 3d.

As illustrated in FIG. 3e, the manufacturing process can also include an additional step of producing a second blocking flaring 20 ′ at the ends of the tubes 2 inserted in the first external collars 42e. Said step of making the second flares 20 ′ is carried out in particular after the step of making the first flares 20.

Thus, it can be seen that the heat exchanger 1, owing to the fact that it comprises a collecting plate comprising first collars 42i, 42e particular, allows a reduction in the pitch P of tube 2 and therefore an increase in its performance.

Claims (10)

1. Collector plate (4) of a collector box (3) intended to be disposed within a heat exchanger (1), said collector plate (4) comprising orifices (40) for insertion intended to receive ends of tubes (2), said orifices (40) being bordered by first collars (42i, 42e) comprising peripheral walls intended to encircle the wall of the ends of tubes (2), characterized in that said first collars (42i, 42e) form first internal collars (42i), the peripheral wall of which is intended to project towards the inside of the manifold (3), and first external collars (42e), of which the peripheral wall is intended to project towards the outside of the manifold (3), said first external (42e) and internal (42i) collars being arranged alternately on the collector plate (4). 2. Collector plate (4) according to the preceding claim, characterized in that the pitch (P) between two first collars (42i, 42e) is between 5 and 7.4mm, preferably between 5.5 and 7.1mm. 3. Heat exchanger (1) comprising: ° a bundle of tubes (2) comprising a multitude of tubes (2) arranged parallel to each other, ° two manifolds (3), a manifold (3) being arranged on each side of the bundle of tubes (2), each manifold (3) comprising a manifold plate (4) according to one of the preceding claims. 4. Heat exchanger (1) according to claim 3, characterized in that it comprises at least one compressible seal (5) forming second internal collars (521) against an external face (4b) of the first internal collars (421) and second external collars (52e) against an internal face (4a) of the first external collars (42e). 5. Heat exchanger (1) according to the preceding claim, characterized in that it comprises a seal (5) unique by manifold (3), said seal (5) being pressed on the inner face (4a) of the collector plate (4), and that, at the level of the orifices (40), said seal (5) forms the second internal collar (52i) against the external face (4b) of the first internal collars ( 42i), covers the protruding end of the wall of the first internal collars (42i), runs along the internal face (4a) of the collector plate (4) to join the first external collars (42e) and form the second external collar ( 52e) against the internal face (4a) of said first external collars (42e). 6. Heat exchanger (1) according to one of claims 4 or 5, characterized in that the ends of the tubes (2) have a first flare (20) so as to compress the second collars (52i, 52e) from to at least one seal (5) within the first collars (42i, 42e). 7. Heat exchanger (1) according to claim 6, characterized in that the ends of the tubes (2) inserted in the first external collars (42e) comprise a second flaring (20 ') blocking formed on the part of said tubes ( 2) protruding from said first external collars (42e). 8. Method for manufacturing a heat exchanger (1) comprising: ° a bundle of tubes (2) comprising a multitude of tubes (2) arranged parallel to each other, and ° two manifolds (3), a manifold (3) being arranged on each side of the bundle of tubes (2) , each manifold (3) comprising a manifold plate (4), said manifold plate (4) comprising orifices (40) inside which the ends of the tubes (2) are introduced, said method comprising the following steps: ° alternating formation of the first internal collars (42i) and the first external collars (42e) of the collector plates (4), ° installation of at least one compressible seal (5) so as to form second collars internal (52i) against the external face (4b) of the first internal collars (42i) and of the second external collars (52e) against the internal face (4a) of the first external collars (42e), ° insertion of the ends of the tubes (2) in the first internal collars (42i) and the first external collars (42e), ° making a first flare (20) of the ends of the tubes (2) so as to compress the at least one seal (5). 9. The manufacturing method according to the preceding claim, characterized in that it comprises an additional step of producing a second flare (20 ') for blocking the ends of the tubes (2) inserted in the first external collars (42e). 10. The manufacturing method according to one of claims 8 or 9, characterized in that the step of alternately forming the first internal collars (42i) and the first external collars (42e) is carried out by stamping. 1/4