EP0624772B1 - Heat-exchanger for motor vehicle - Google Patents

Description

The invention relates to a heat exchanger heat, especially for motor vehicles.

It relates more particularly to an exchanger type heat including a collector plate with substantially circular holes and a bundle of tubes fitted with fins, in which each tube has an end of suitable shape, received at sealing in a hole in the collector plate.

By the expression "substantially circular" we intends to clarify that the holes in the collector plate and the sections of the ends of the tubes have a shape circular or a shape which can be an oval shape or elliptical determined by a major axis and a minor axis of symmetry.

In this type of heat exchanger, the sealing between each end of tubes and the collector plate is most often ensured by a gasket in elastomer comprising compressible collars of which each is compressed between the end of the tube and a collar bordering the corresponding hole in the plate collector.

In a heat exchanger of the aforementioned type, each end of the tube can be provided with a flare obtained by deformation of the wall of the tube, this deformation having the function of ensuring the retention of the collector plate on the finned tube bundle and contribute to the seal between the tube and the collector plate.

In addition, a fluid manifold is able to be attached to one end of the beam finned tubes thus formed and more particularly on the collector plate so that form a heat exchanger.

When used under conditions extremes of this type of heat exchanger, the Applicant has observed that a phenomenon is occurring that a force directed in the axial direction tubes tended to move some of the tubes relative to the collector by dragging them in the holes of the collector plate.

This phenomenon has the consequence of causing a loss of tightness between the ends of the tubes affected and the holes and, in extreme cases, a deterioration of the seal provided between the end of the tube and the hole.

In the state of the art, it is also known to have means of stops between the box manifold and at least one end of the tubes.

In particular, as described in the document US 5062476, these stop means come from the wall side and the ends of these tubes come rely on these stop means during the mounting tubes in the manifold.

These abutment means thus make it possible to correctly position the tubes so that they can't sink too deep into inside the manifold.

Once this assembly has been carried out, the tubes are rigidly attached to the collector plate and cannot be dismantled by a soldering operation carried out by a passage of the assembly to the brazing furnace.

Due to this soldering operation, no possibility of moving the tubes in the collector is not possible but it requires an operation fixing by brazing which is incompatible with the fixing of the tubes on the collector by a joint sealing and flaring of the ends of these tubes

In document EP 0567 397, the stop means are arranged so that they penetrate inside the tubes to immobilize in torsion or rotation of the tube bundle.

As described in this document, the means of stopper in no way prevents axial displacement of the tube during operation of the exchanger.

The present invention proposes to remedy the aforementioned drawbacks.

To this end, it offers a heat exchanger, especially for a motor vehicle, comprising a bundle of tubes fitted with fins in which the ends of the tubes are sealed in holes in a header plate on which is mounted a manifold and abutment means provided between the manifold and at least one end of the tubes to lean on said end, characterized in that the stop means come from the bottom wall of the manifold to lean on a surface radial from the end so as to limit the displacement in an axial direction of the end of the tube relative to the collector during operation of the exchanger.

Thanks to the invention the axial displacement of the entire tube concerned is limited or even prevented by the stop means.

According to another characteristic of the invention, the stop means consist of a finger from the manifold.

According to another characteristic, the means of stop consist of a rib from the box collector.

According to another characteristic, the means of stopper are connected to at least one of the side walls of the manifold by a veil.

According to another characteristic, the means of stopper are located between at least two tube ends adjacent.

According to another characteristic, the means of abutment rest on the terminal edge of the end.

According to another characteristic, the means of stop have a flat bearing surface on the end.

According to another characteristic, the means of stop are supported on a shoulder provided in the end.

According to another characteristic, the means of abutment are based on a localized region of the end.

• la figure 1 est une vue partielle en coupe longitudinale selon la ligne I-I de la figure 2 et montrant un échangeur de chaleur selon une première forme de réalisation de l'invention ;
• la figure 2 est une vue en coupe partielle selon la lige II-II de la figure 1 ;
• la figure 3 est une vue partielle en coupe longitudinale selon la ligne III-III de la figure 4 et montrant un échangeur de chaleur selon une seconde forme de réalisation de l'invention ;
• la figure 4 est une vue partielle en coupe selon la ligne IV-IV de la figure 3.
• la figure 5 est une vue partielle en coupe longitudinale selon la V-V de la figure 6 montrant un échangeur de chaleur selon une troisième forme de réalisation de l'invention ;
• la figure 6 est une vue partielle en coupe selon la ligne VI-VI de la figure 5.

The other characteristics and advantages of the invention will now emerge from the description which follows, with reference, by way of example, to the appended drawings, in which:

• Figure 1 is a partial view in longitudinal section along line II of Figure 2 and showing a heat exchanger according to a first embodiment of the invention;
• Figure 2 is a partial sectional view along line II-II of Figure 1;
• Figure 3 is a partial view in longitudinal section along the line III-III of Figure 4 and showing a heat exchanger according to a second embodiment of the invention;
• FIG. 4 is a partial sectional view along the line IV-IV of FIG. 3.
• Figure 5 is a partial view in longitudinal section along the VV of Figure 6 showing a heat exchanger according to a third embodiment of the invention;
• FIG. 6 is a partial sectional view along the line VI-VI of FIG. 5.

We now refer to Figures 1 and 2 which show a heat exchanger consisting of a bundle 2 formed of a multiplicity of tubes 4 of respective axes XX parallel being arranged in two rows parallels R1, R2.

The tubes pass through a multiplicity of fins 6 extending, here, perpendicular to the axes XX of the tubes.

The ends 8 of the tubes 4 are able to be received with sealing in a collecting plate 10 which comprises a core 12 of generally rectangular shape, at through which are arranged, in correspondence ends 8 of tubes 4, a multiplicity of holes 14 of shape corresponding to the shape of the ends 8 and of which each is bordered by a collar 16 extending from fins directions 6.

As shown in Figure 1, the plate manifold 10 has a peripheral rim 18 delimiting a peripheral groove 20 and forming a multiple folding legs 22.

On the face of the collecting plate opposite the fins 6 is arranged a compressible seal 24, produced, preferably, in an elastomeric material.

This seal includes a core 26 applied against the core 12 of the collector plate and provided with collars compressible 28 capable of being compressed between a collar 16 of the collector plate 10 and the end 8 of the tube 4 by any suitable means, such as mounting to force of the end 8 in the collars 28 or by flaring of said ends as is known per se.

The core 26 of the seal 24 is provided with a flange 30 received in the throat 20 and intended to be compressed by a peripheral edge 32 of a manifold 34.

The seal between the manifold 34 and the collector plate 10 is ensured by compression of the rim 30 after folding of the tabs 22 presented by the collector plate.

The manifold 34 has a form of bowl whose open edge corresponds substantially to the arrangement of the peripheral edge 32 and has a wall bottom 36 opposite the open edge while being disposed substantially parallel to the collector plate 10, this bottom wall coming to join the peripheral edge 32 by longitudinal side walls 38 and walls transverse lateral 40.

The general structure of the heat exchanger, as just described so far, is in itself known and will not be described in more detail.

The manifold 34 also carries stop means 42 making it possible to limit or even prohibit, the displacement of the end 8 of the tubes 4 in the holes 14 of the collector plate 10 and more particularly at the collars 28 of the joint sealing 24, these abutment means being arranged at vicinity of at least one end of the tube.

As shown in Figure 1, the stop means consists of a finger 44 originating inside of the manifold 34 and, more particularly in the case of this figure, from the internal face of the bottom wall 36 to reach the terminal edge 46 from the end 8 of the tube concerned, edge considered substantially perpendicular to the axis XX of the tube while being placed at a distance from the bottom wall 36 of the manifold 34.

More particularly, with reference in addition to Figure 2, the free end 48 of the finger 44 which has a flat surface substantially parallel to the edge terminal 46, relies on a localized region of edge 46 so as not to impede the circulation of the this tube, this finger being located near the end 8 but eccentrically to the XX axis of the tube 4 while having most of his body outside the perimeter delimited by the edge 46.

Also, as best shown in Figure 2, finger 44 can be replaced by a rib 50 from of the longitudinal side wall 38 of the box fluid and coming to rest by its free edge 48 on a localized region of the edge 46 of the end 8 of the tubes 4, this rib extending in whole or in part along of this side wall by being substantially parallel to the axis XX of the tube concerned and having a part terminal 52, opposite wall 38, located at distance from axis XX of tube 4.

The rib 50, previously described, can be also from the transverse side wall 40 of the manifold 34 and rely on a region located from the edge 46 of the end 8 of the tube 4 relates.

As shown in Figure 2, it can be expected a rib 50 associated with a tube 4 of each row R1, R2 of the finned tube bundle.

Thanks to these abutment means constituted either by a finger, either by a rib, arranged in the vicinity of the tubes concerned, these cannot be subjected to axial displacement along their axis XX and therefore guarantee a perfect seal between the ends of these tubes and the header plate.

We now refer to Figures 3 and 4 which show an alternative embodiment of the invention and which, for this, will include the same references.

In this variant, a finger 44 comes from the bottom wall 36 of the manifold 34 being located between two adjacent tubes 4 located on two rows R1, R2.

This finger, as visible in FIG. 4, presents a section of parallelepiped shape so that that, at its free end 48, the small sides of the finger come to rest on the edges 46 of ends 8 of two adjacent tubes.

This finger 44 can be connected to the side wall transverse 40 of the manifold by a veil 54 taking birth along a longitudinal edge of this finger to reach said transverse side wall.

With this finger and this veil, a stop means is formed for two adjacent tubes.

We now refer to Figures 5 and 6 which show another embodiment of the invention.

As best seen in these figures, the end 8 of the tubes 4 is mounted to seal in the plate collector 10 by deformation of this end, deformation obtained during a so-called flaring operation.

This flaring operation, known in the art Anterior, consists in increasing the section of the body 56 of the tube 4 at its junction with the plate manifold 10 so as to compress the collar 28 disposed between the outer wall of this end and the collar 16 of the collector plate by forming a first flare 58.

Thanks to this operation, sealing is ensured between the end 8 of the tube 4 and the collector plate 10 and the tube 4 has a radial shoulder 60 located between the body 56 of the tube and the first seam 58.

Preferably, it is planned to do a second flaring 62 following the first flaring in direction of the free edge 46 of the end 8, this second flaring of larger diameter than the first flare allowing a stop of the tube 4 in the hole 14.

This second flare 62 has the result of creating a second shoulder 64 disposed at a distance from the first shoulder 60 of the first flare 58 and being located between the first flare and the second flare.

With such a provision, it is intended that the stop means 42 bear on the end 8 of the tube 4 coming into contact on a shoulder, i.e. the shoulder 60 of the first flare 58, i.e. the shoulder 64 of the second flare 62.

To do this, a finger 44 is provided from the bottom wall 36 of the manifold and of which the free end 48 of the finger enters either the first flare 58, i.e. in the second flare 62 in supported by said free end on the shoulder concerned.

Referring to Figure 5, the free end 48 of finger 44 is supported on the second shoulder 64 of the second flare 62 and presents, in section, as visible in Figure 6, a form in which a body 66 substantially rectangular door to each end a larger guide portion 68 transverse thickness. These guide portions have a portion of outer cylindrical surface 70 whose diameter corresponds substantially to the diameter of the flare considered, here the flare 62, and two walls vertical 72 coming to join the body 66 of the finger 44.

Preferably, the distance A considered between the portions of the cylindrical surfaces 70 corresponds substantially to the diameter of the portions of the end concerned by this flaring, here the flaring 62 and two vertical walls 72 coming to join the body 66 finger 44.

Preferably, and as is visible in Figure 6 which shows one end of the tube oval with flares, the distance A of the portions of cylindrical surface corresponds substantially to the small dimension of the flare oval and the end free 48 carries a tilting support surface 74 corresponding to the inclination of the shoulder on which it presses and the thickness B of the body 66 is sufficient small to minimize the flow of fluid in the tube in question.

The present invention is not limited to exemplary embodiments described but encompasses all variant.

In particular, the description of the examples of embodiment reports abutment means for a tube and / or for two adjacent tubes of two rows different, and it can be considered using these stop means for several tubes each comprising a separate stop means and / or for two adjacent tubes belonging to the same row of tubes.

Claims (9)

1. Heat exchanger, especially for a motor vehicle, comprising a bank of tubes (4) equipped with fins (6) in which the extremities (8) of the tubes are mounted so as to be leaktight in holes (14) of a manifold plate (10) onto which a manifold box (34) is mounted, and abutment means (42) provided between the manifold box (34) and at least one extremity (8) of the tubes (4) in order to bear on the said extremity, characterised in that the abutment means issue from the back wall (36) of the manifold box (34) opposite the manifold plate (10) so as to bear on a radial surface (46, 60, 64) of the extremity (8) in such a way as to limit the shifting, in an axial direction, of the extremity of the tube with respect to the manifold while the exchanger is in operation.
2. Heat exchanger according to Claim 1, characterised in that the abutment means consist of a spigot (44).
3. Heat exchanger according to Claim 1 or 2, characterised in that the abutment means consist of a rib (50).
4. Heat exchanger according to one of the preceding claims, characterised in that the abutment means (44) are linked to at least one of the side walls (38, 40) of the manifold box by a web (54).
5. Heat exchanger according to one of the preceding claims, characterised in that the abutment means are situated between at least two extremities (8) of adjacent tubes (4).
6. Heat exchanger according to one of Claims 1 to 5, characterised in that the abutment means bear on the terminal edge (46) of the extremity (8).
7. Heat exchanger according to one of the preceding claims, characterised in that the abutment means (42) exhibit a flat surface (48) for bearing on the extremity (8).
8. Heat exchanger according to one of Claims 1 to 4, characterised in that the abutment means (42) bear on a shoulder (60, 64) provided in the extremity (8).
9. Heat exchanger according to one of the preceding claims, characterised in that the abutment means bear on a localised region of the extremity (8).

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