EP0535664B1 - Tubular header box for heat-exchanger - Google Patents

Description

The invention relates to heat exchangers of the type comprising at least one fluid box having an elongated tubular wall, and a multiplicity of parallel tubes entering the fluid box through openings in the tubular wall.

Such an exchanger, used in particular as a condenser in a motor vehicle air conditioning installation, is described in EP-A-0 198 581. In this known exchanger, the tubular wall has, in each of its zones comprised between two consecutive receiving openings of tubes, a convexity turned outwards both in the longitudinal direction and in the transverse or circumferential direction. This transverse convexity does not easily immobilize the tubular wall in rotation about its axis during its assembly with the tubes, so that it risks pivoting under the force exerted by the tubes which penetrate into the openings, leading incorrect positioning of the fluid box with respect to the tubes or even preventing assembly from taking place.

The object of the invention is to remedy this drawback.

The invention relates to a heat exchanger fluid box comprising a tubular wall traversed by a multiplicity of openings aligned in the axial direction to receive fluid circulation tubes, characterized in that said tubular wall, in each of the portions of its length delimited by said openings, is entirely located on one side of a contact plane extending parallel to its axial direction, opposite said openings, and which comes into contact with it at at least two spaced contact points in the circumferential direction.

At least two different contact planes can be provided for different portions of the length of the tubular wall, for example for that or those housing a transverse wall whose periphery is in contact with the internal surface of the tubular wall on the one hand, and for those which do not comprise such a partition on the other hand.

Thanks to this configuration, the tubular wall can be applied stably, without the risk of pivoting, on one or more flat bearing surfaces on which the tubular wall is supported by all of its contact points, or on discrete support elements arranged in one or more planes on which the tubular wall is supported by its different contact points respectively. Such a surface or such support elements can be used, either to give the tubular wall a prior orientation, which will be maintained by clamping means during assembly with the tubes, or during this assembly itself. In the latter case, the support elements may if necessary belong to the bundle formed by the tubes and by fins extending between them.

Most often, the openings are elongated in the circumferential direction, and are symmetrical with respect to an axial plane of the tubular wall. The contact plane will then be chosen perpendicular to this axial plane of symmetry.

According to one embodiment of the invention, the tubular wall is in contact with the contact plane along at least one straight line perpendicular to its axial direction. In particular, it may include a flat surface portion located in the contact plane.

According to another embodiment, the tubular wall has, between its two contact points, or between two contact zones spaced in the circumferential direction and each extending over a certain axial length, a concavity facing the contact plane. Such a concavity has the advantage of improving the resistance to pressure of the tubular wall compared to the configuration comprising a transverse contact line segment or a portion of planar contact surface.

Contact segments, portions of planar contact surfaces and contact areas as described above, identical or different, are provided in each of the regions of the wall comprised between two consecutive openings.

• la figure 1 est une vue partielle d'une boîte à fluide selon l'invention, partiellement en coupe par un plan axial parallèle au plan de contact;
• la figure 2 est une vue partielle de cette boîte à fluide, en coupe par son plan de symétrie axial; et
• les figures 3 et 4 sont des sections prises selon les lignes III-III et IV-IV respectivement de la figure 2.

Other characteristics and advantages of the invention will emerge from the detailed description given below of a few exemplary embodiments, and from the appended drawings in which:

• Figure 1 is a partial view of a fluid box according to the invention, partially in section through an axial plane parallel to the contact plane;
• Figure 2 is a partial view of this fluid box, in section through its axial plane of symmetry; and
• Figures 3 and 4 are sections taken along lines III-III and IV-IV respectively of Figure 2.

The illustrated fluid box, intended in particular to be part of a condenser of an air conditioning installation of the passenger compartment of a motor vehicle, comprises a tubular wall 1 which can in particular be formed from a rectangular metal sheet rolled into a cylinder shape and welded on itself edge to edge in a leaktight manner according to a generator 2. In the wall 1 are formed openings 3 elongated in the circumferential direction and mutually aligned in the direction of its axis 4, intended to receive the ends of the condenser fluid circulation tubes.

The fluid box also comprises transverse partitions 5a, 5b, constituted by discs extending transversely inside the tubular wall 1, immobilized by crimping and brazed in a sealed manner by their periphery to the internal surface of the wall 1 Figure 1 shows such a partition 5a disposed in the vicinity of an axial end 6 of the wall 1 and constituting an end wall of the fluid box. FIG. 2 shows an intermediate partition 5b separating two compartments 7 and 8 of the fluid box into each of which opens a part of the openings 3.

Viewed from the outside of the fluid box, the openings 3 are located at the bottom of respective depressions 9 of the tubular wall.

As seen in Figures 2 and 3, the outer surface of the tubular wall 1 present in the region between two consecutive openings 3, in line with the partition 5b and in correspondence with a flat part of the edge thereof , a surface portion 10 included in a plane P parallel to the axis 4 and perpendicular to the longitudinal plane of symmetry of the wall 1. In other words, this outer surface is flattened over a certain length both in the axial direction only in the circumferential direction of the tubular wall.

Figures 2 and 4 show that the tubular wall, midway between two consecutive openings in a region free of transverse partition, is convex outward in the longitudinal direction, but has a concavity 11 in the circumferential direction. It therefore comes into contact with the plane P exclusively by two points A and B spaced in the circumferential direction.

In a variant not illustrated, the deformation of the tubular wall inwards to make the contact points is limited by the presence of the transverse partitions such as 5a and 5b, and is less significant in the length portions comprising such partitions than in the other portions. There are then two different contact planes for the entire fluid box, a plane closer to the axis of the tubular wall for the portions without partition and a plane further away from this axis for the portions with partition.

Other configurations than those which have just been described by way of examples are possible for the region of the tubular wall comprised between two consecutive openings. In particular, the tubular wall may be convex in the longitudinal direction and flattened in the circumferential direction, and come into contact with the plane P exclusively along a straight line extending in the circumferential direction, or flattened in the longitudinal and concave direction in the circumferential direction, thus coming into contact with the plane P exclusively along two lines extending in the longitudinal direction and spaced apart in the circumferential direction. All these configurations can be found both at the level of a transverse partition and in a region free of transverse partition.

As known per se, the openings 3 can be produced in particular by sawing or by punching. The dishes and hollows according to the invention can be obtained by localized deformations of the tubular wall, preferably before making the openings 3 so as not to modify the shape of these. The transverse partitions 5a, 5b may have at their periphery, before assembly, circumferential dishes or recesses corresponding to those of the tubular wall. Alternatively, the partitions can be circular, the deformation of the outer surface of the tubular wall being accompanied by a corresponding deformation of the partitions and / or a variation in the thickness of the tubular wall.

Claims (9)

1. A fluid manifold for a heat exchanger, comprising a tubular wall (1) having a multiplicity of through apertures (3) which are aligned in the axial direction for receiving fluid flow tubes, characterised in that the said tubular wall, in each of the portions of its length which are delimited by the said apertures, is situated entirely on one side of a plane of contact (P) which extends parallel to its axial direction, in facing relationship with the said apertures, and which comes into engagement with it in at least two points of contact (A, B) which are spaced apart in the circumferential direction.
2. A fluid manifold according to Claim 1, characterised in that the tubular wall defines at least two different planes of contact for the different portions of its length.
3. A fluid manifold according to Claim 2, characterised in that it includes at least one transverse bulkhead (5a, 5b), the periphery of which is in engagement with the internal face of the tubular wall, and in that the plane of contact is spaced further away from the axis of this latter for the portion or portions of its length containing a transverse bulkhead, than for the other portions.
4. A fluid manifold according to one of the preceding Claims, characterised in that the apertures are symmetrical with respect to an axial plane of the tubular wall at right angles to the plane or planes of contact.
5. A fluid manifold according to one of the preceding Claims, characterised in that the apertures are elongated in the circumferential direction.
6. A fluid manifold according to one of the preceding Claims, characterised in that the tubular wall is in engagement with the plane of contact in at least one straight segment at right angles to its axial direction.
7. A fluid manifold according to Claim 6, characterised in that the tubular wall includes a flat surface portion (10) situated in the plane of contact.
8. A fluid manifold according to one of Claims 1 to 6, characterised in that the tubular wall is in engagement with the plane of contact in at least two contact zones spaced apart in the circumferential direction, with each one extending over a particular axial length.
9. A fluid manifold according to one of Claims 1 to 5 and 8, characterised in that the tubular wall has, between its two points or zones of contact (A, B), a concavity (11) open towards the plane of contact.

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