EP2764317B1 - Heat exchanger - Google Patents

Description

The invention relates to a heat exchanger for an air supply circuit of a motor vehicle engine.

The invention applies to the general field of air supply of motor vehicle engines, and more particularly to engines whose air supply comes from a compressor or a turbocharger, it is called air of overeating.

It is known to cool the charge air leaving the compressor by means of a heat exchanger which is also called charge air cooler (abbreviated RAS).

In this case, the heat exchanger RAS makes it possible to cool the engine supercharging air by heat exchange with another fluid such as outside air or a liquid such as the water of the engine cooling circuit, thus forming a heat exchanger air / air or liquid / air type.

Such exchangers generally comprise a heat exchange bundle comprising a stack of tubes or plates defining respective circulation channels for the fluids, so as to allow a heat exchange between the two fluids circulating within the bundle.

The beam is in a known manner received in a housing. Such a housing may comprise end plates on either side of the stack of plates or tubes of the bundle defining the fluid circulation channels, and generally one or more lateral cheeks connecting these end plates.

In order to allow the admission into the bundle and the evacuation of the fluid, fluid intake and outlet manifolds are, according to a known solution, attached to the casing receiving the heat exchange bundle. The document FR 2 933 176 discloses such a heat exchanger for charge air cooling of a motor vehicle engine. The casing receiving the beam plays a structural role by participating in the rigidity of the exchanger.

However, in operation, the supercharging pressure can deform the housing, in particular the side cheeks of the housing.

This pressure generates a level of mechanical stress that may be greater than the limit of the material used.

It is known to increase the thickness of the material or to provide additional components to withstand such mechanical stresses.

Moreover, to limit in particular the manufacturing costs of an exchanger is tending more and more to a reduced thickness of the materials. However, this results in reduced resistance to mechanical stresses.

The invention aims to provide a heat exchanger does not have the disadvantages of the prior art.

• un faisceau d'échange thermique entre fluides,
• un carter de réception dudit faisceau, ledit carter comportant au moins deux plaques d'extrémité de part et d'autre dudit faisceau dans le sens d'empilement de canaux de circulation de fluide, et au moins une joue latérale reliant lesdites au moins deux plaques d'extrémité,
  • une boîte collectrice d'entrée de fluide, et
• une boîte collectrice de sortie de fluide, configurée pour l'admission de l'air de suralimentation audit moteur, caractérisé en ce que ladite au moins une joue latérale dudit carter présente au moins une zone d'absorption de contraintes, adjacente à ladite au moins une boîte collectrice d'entrée, présentant au moins une surface sensiblement convexe, la convexité étant orientée vers la direction générale de contraintes, de façon à résister aux contraintes mécaniques exercées sur ledit carter lors de l'écoulement dudit fluide dans ledit faisceau depuis ladite boîte d'entrée de fluide vers ladite boîte de sortie de fluide.

For this purpose, the subject of the invention is a heat exchanger, configured for the cooling of charge air of a motor vehicle engine, said exchanger comprising:

• a heat exchange beam between fluids,
• a casing for receiving said beam, said casing comprising at least two end plates on either side of said beam in the stacking direction of fluid circulation channels, and at least one lateral cheek connecting said at least two plates end,
  • a fluid inlet manifold, and
• a fluid outlet collecting box, configured for the admission of charge air to said engine, characterized in that said at least one lateral cheek of said casing has at least one stress absorption zone, adjacent to said at least one an inlet manifold, having at least one substantially convex surface, the convexity being oriented towards the general direction of stress, so as to withstand the mechanical stresses exerted on said housing during the flow of said fluid in said bundle from said box fluid inlet to said fluid outlet box.

• ladite au moins une surface convexe est ménagée sensiblement au centre de ladite au moins une joue latérale;
• ladite au moins une surface convexe s'étend sensiblement sur toute ladite au moins une joue latérale;
• ledit carter comporte des moyens de rigidification formés d'une seule pièce avec ledit carter;
• lesdits moyens de rigidification sont réalisés par déformation dudit carter;
• ladite au moins une zone d'absorption de contraintes comporte des moyens de rigidification;
• ladite au moins une joue latérale présente au moins une bordure repliée selon une arête de pliage, pour le raccordement à une plaque d'extrémité, et ladite au moins une joue latérale présente des moyens rigidification agencés sensiblement au niveau de l'arête de pliage;
• ladite au moins une joue latérale comporte des moyens de limitation de contraintes sur au moins une zone de raccordement à une plaque d'extrémité;
• ladite au moins une joue latérale présente au moins une gorge de limitation de contraintes sur au moins un contour périphérique de ladite au moins une joue latérale.

Said exchanger may further comprise one or more of the following characteristics, taken separately or in combination:

• said at least one convex surface is formed substantially in the center of said at least one side cheek;
• said at least one convex surface extends substantially over all of said at least one side cheek;
• said casing comprises stiffening means formed in one piece with said casing;
• said stiffening means are made by deformation of said housing;
• said at least one stress absorption zone comprises stiffening means;
• said at least one lateral cheek has at least one folded edge along a folding edge, for connection to an end plate, and said at least one lateral cheek has stiffening means arranged substantially at the fold edge;
• said at least one lateral cheek comprises stress limiting means on at least one end plate connection zone;
• said at least one lateral cheek has at least one constriction restriction groove on at least one peripheral contour of said at least one lateral cheek.

• la figure 1 représente un échangeur thermique,
• la figure 2 est une vue schématique et simplifiée d'une surface convexe d'une joue latérale du carter de l'échangeur de la figure 1, et
• la figure 3 représente une variante de l'échangeur thermique avec une joue latérale présentant deux surfaces convexes.

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

• the figure 1 represents a heat exchanger,
• the figure 2 is a schematic and simplified view of a convex surface of a lateral cheek of the casing of the heat exchanger of the figure 1 , and
• the figure 3 represents a variant of the heat exchanger with a lateral cheek having two convex surfaces.

In these figures, the substantially identical elements bear the same references.

We have shown on the figure 1 , a heat exchanger 1 especially for a motor vehicle.

This exchanger is intended to be disposed in an air supply circuit of an engine.

Such an exchanger 1 is configured to cool the charge air for a combustion engine of the motor vehicle.

This exchanger 1 comprises a bundle of tubes or plates for heat exchange between a first fluid such as supercharging air and a second fluid such as coolant.

This bundle of tubes or plates is received in a housing 3.

The exchanger 1 further comprises a first manifold 5 for the inlet of the first fluid, and a second manifold 7 for the fluid outlet.

According to the embodiment described, the outlet box 7 is fixed on the cylinder head of the engine (not shown) to allow the admission of the cooled air, and thus forms an intake box of the first fluid.

• deux plaques d'extrémité 9 de part et d'autre du faisceau dans le sens d'empilement des plaques ou des tubes définissant les canaux de circulation de fluide, et
• au moins une joue latérale 11,12 reliant les deux plaques d'extrémité 9.

According to the illustrated example, the casing 3 comprises:

• two end plates 9 on either side of the bundle in the stacking direction of the plates or tubes defining the fluid circulation channels, and
• at least one lateral cheek 11, 12 connecting the two end plates 9.

According to the illustrated embodiment, the heat exchanger 1 comprises a first lateral cheek 11 adjacent to the input box 5, and a second lateral cheek 12.

The first side cheek 11 is arranged near the inlet box 5 and is therefore substantially at the level of the intake of the supercharging air relative to the direction of air flow.

Frontal cheek 11 is referred to with respect to the flow direction of the fluid. The The rear part of the exchanger 1 is defined by the output box 7 mounted on the cylinder head of the engine (not shown).

The lateral cheek 11,12 have zones of connection to the end plates 9.

According to the illustrated example, the lateral cheeks 11,12 respectively have folded peripheral edges 15,17 for connection to the end plates.

These borders 15, 17 are folded along a folding edge 19.

These edges 15, 17 are held at the end plates 9, for example by crimping.

The set is for example soldered thereafter.

The casing 3 further comprises at least one stress absorption zone to withstand the stresses exerted on the casing 3 during the flow of the charge air.

The absorption zone or zones are arranged adjacent to the input box 5.

According to the embodiment illustrated on the figure 1 it is the first lateral cheek 11 which has such an absorption zone.

This is to provide a substantially convex surface 13 on the side cheek 11, as shown schematically on the figure 2 .

The convexity is oriented towards the general direction of the stresses exerted on the casing 3 during the flow of the supercharging air, as schematically illustrated by arrow F.

This convex surface 13 is here arranged substantially in the center of the lateral cheek 11.

In addition, this convex surface 13 extends substantially over the entire lateral cheek 11. This surface 13 thus extends substantially over the entire height and over the entire width of the lateral cheek 11.

Such a convex surface 13 makes it possible to limit the displacements of the surface of the lateral cheek 11 during the flow of the supercharging air from the inlet box 5 to the outlet box 7.

In fact, a lateral cheek 11 is obtained which is more rigid and therefore better resists the mechanical stresses exerted on the lateral cheek 11 during the flow of the supercharging air towards the engine (not shown).

For the same order of resistance to mechanical stresses, it can then provide a side cheek 11 thinner than in the prior art. By way of example, for the same order of resistance, it is possible to go from a cheek 3 mm thick to a cheek 1.5 mm thick having such a convex surface 13.

According to an alternative embodiment, it is possible for the lateral cheek 11 to have two convex surfaces 13 instead of just one, as shown in FIG. figure 3 .

With these two convex surfaces 13, the lateral cheek 11 is all the more resistant; which further reduces the thickness of the cheek 11.

The housing 3 may also have stiffening means (not shown in the figures).

These stiffening means are formed in one piece with the housing 3. For example, the stiffening means are made by deformation of the housing 3.

The stiffening means are for example provided at the stress absorption zone or zones of the casing 3.

In addition to the convex surface 13, the lateral cheek 11 may have such stiffening means.

As an example, there may be mentioned means for stiffening deformations that are substantially cross-shaped. Such cross deformation may be provided substantially in the center of the lateral cheek 11 or in the center of the convex surface (s) 13 of cheek 11.

We can alternatively provide deformations made substantially in the form of domes.

According to an alternative embodiment, the first lateral cheek 11 may have stiffening means at the folding edge 19 of the folded peripheral edges 15 for connection with the end plates 9.

Such stiffening means may for example be made by deformation of the material of the cheek 11, for example forming a hump, at the level of the folding edge 19. These stiffening means have for example a substantially triangular shape whose apex is at the level of the folding edge 19 and whose base connects the folded peripheral edge and the lateral cheek 11. Such stiffening means are generally called "bulldozers".

In addition, the casing 3 may comprise stress limiting means 21 on one or more connection zones of the lateral cheek 11,12 with the end plates 9.

According to the illustrated embodiment, the first lateral cheek 11 includes such limitation means 21 on its peripheral contours.

By way of example, the limiting means may include limiting grooves 21 (see FIG. figure 2 ).

According to the illustrated embodiment, the first lateral cheek 11 therefore has limiting grooves 21 on its peripheral contours forming zones of connection with the end plates 9.

Moreover, the casing 3 can still carry inlet and outlet pipes 23 for the second fluid (cf. figure 3 ).

Referring again to the figure 1 , the manifolds 5.7, for their part are for example made by molding.

The manifolds 5 and 7 are arranged so that after passing through the beam, the cooled air leaves the exchanger 1 to supply the engine.

For this, the input box 5 communicates with an air inlet duct 25.

In order to allow the admission of the cooled air into each of the cylinders of the engine (not shown), the outlet box 7 is open to allow the passage of the cooled air to the engine.

The positioning of the input and output boxes 7 is given for illustrative purposes.

Thus, the charge air enters the exchanger 1 via the inlet box 5 for the first fluid, circulates in the heat exchange bundle 3 and then leaves the exchanger 1 via the outlet box 7 for the first fluid to power the engine (not shown).

As for the second fluid, it enters the heat exchange bundle, through an inlet pipe 23 for the second fluid, circulates in the heat exchange bundle, to exchange heat with the supercharging air to cool and then leaves the heat exchange bundle by an outlet pipe 23 for the second fluid.

It will thus be understood that such a heat exchanger casing 3 for admitting the supercharging air to the heat engine, is more resistant to the stresses exerted during the flow of air in the exchanger 1 because of the zone of absorption provided for example by one or more convex surfaces of the lateral cheek 11 adjacent to the input box 5, and due to deformations of variable geometries of this side cheek 11.

Claims (9)

1. Heat exchanger configured to cool the supercharged charge air of a motor vehicle engine, said exchanger comprising:

   - a core bundle for exchanging heat between fluids,

   - a casing (3) for housing said core bundle, said casing comprising at least two end plates (9) one on each side of said core bundle in the direction of stacking of fluid circulation channels, and at least one side wall (11) connecting said at least two end plates (9),

   - a fluid inlet header tank (5), and

   - a fluid outlet header tank (7) configured to admit the supercharged charge air to said engine,

   characterized in that said at least one side wall (11) of said casing has at least one stress absorption zone adjacent to said at least one inlet header tank (5) having at least one substantially convex surface (13), the convex face facing in the general direction of stress, so as to withstand the mechanical stresses applied to said casing (3) as said fluid flows through said core bundle from said fluid inlet tank (5) toward said fluid outlet tank (7).
2. Exchanger according to Claim 1, characterized in that said at least one convex surface (13) is formed substantially at the center of said at least one side wall (11).
3. Exchanger according to Claim 1 considered in combination with Claim 2, characterized in that said at least one convex surface (13) extends substantially over the whole of said at least one side wall (11).
4. Exchanger according to any one of the preceding claims, characterized in that said casing (3) comprises stiffening means formed as one with said casing.
5. Exchanger according to Claim 4, characterized in that said stiffening means are produced by deforming said casing.
6. Exchanger according to either of Claims 4 and 5, characterized in that said at least one stress absorption zone comprises stiffening means.
7. Exchanger according to Claim 1 considered in combination with either one of Claims 4 and 5, characterized in that said at least one side wall (11) has at least one border (15) bent over along a bent edge (19) for connection to an end plate (9), and in that said at least one side wall (11) has stiffening means arranged substantially at the bent edge (19).
8. Exchanger according to Claim 1 considered in combination with any one of the preceding claims, characterized in that said at least one side wall (11) comprises stress limiting means on at least one zone of connection to an end plate (9).
9. Exchanger according to Claim 8, characterized in that said at least one side wall (11) has at least one stress limiting groove (21) on at least one peripheral contour of said at least one side wall (11).

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