EP0512903B1 - Tubular header for heat-exchanger and method for its manufacture - Google Patents

Description

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

Such an exchanger, which can be used in particular as a condenser in such a motor vehicle air conditioning installation, is described in EP-A-0 360 362. In this known exchanger, the tubular wall has diametric slots, each partition being introduced laterally through the 'one of these slots and having a suitable contour allowing it to abut against the ends of the same slot. The partition thus immobilized is then brazed to the tubular wall. This arrangement has the drawback of complicating the production of the tubular wall by machining the slots, and imposes an irregular shape for the partition. In addition, these slots create additional risk of leakage.

This same document also provides means for limiting the penetration of the tubes into the fluid box, in the form of shoulders or projections made on the outside of the tubes and which abut against the tubular wall. This arrangement requires special machining of each of the tubes.

The object of the invention is to remedy at least some of the aforementioned drawbacks.

The invention relates to a heat exchanger of the type defined in the introduction, in which the transverse partitions are integral with a connecting piece elongated in the direction of the axis of the tubular wall. Such an exchanger is known from DE-A-3 923 511.

According to the invention, the connecting piece is a bar having notches, mutually spaced in its longitudinal direction, for receiving the transverse partitions, each partition also having a notch for receiving the bar and the latter coming substantially in contact with the wall. tubular in a diametrically opposite position relative to the openings for passage of the tubes.

The transverse partitions may comprise two end partitions defining with the tubular wall the interior space of the fluid box and / or at least one intermediate partition dividing the fluid box into at least two compartments in each of which opens out a part of the tubes.

According to an advantageous characteristic of the invention, the ends of the tubes abut against the connecting piece, which limits the penetration of each of them uniformly.

Preferably, the peripheral edges of the transverse partitions and / or the tubes are brazed to the tubular wall.

According to another embodiment of the invention, the bar is in the form of a gutter with a cross-section in an arc of a circle and has through openings mutually spaced in its longitudinal direction, each partition having along its perimeter a recess whose height and the circumferential extent correspond to the thickness and to the arc length of the gutter, this recess being interrupted by a radial projection which engages in an opening in the gutter to ensure the attachment of the partition to the gutter, and this resting on the tubular wall in a diametrically opposite region with respect to the tube passage openings.

In each of these last two embodiments, the connecting piece can have a multiplicity of regularly spaced notches or openings, some of them only being associated with transverse partitions, depending on the length of the compartments to be produced. . The same connecting piece can thus be used for fluid boxes of the same length but differing by the position of the partitions.

The invention also relates to a method of producing a heat exchanger as defined above, in which one introduces, by an open end of the tubular wall, the connecting piece carrying the transverse partitions and which slides it longitudinally until the partitions reach the positions they must occupy, before introducing the ends of the tubes into the fluid box through the openings in the tubular wall.

Advantageously, the peripheral edges of the transverse partitions and / or the tubes are brazed to the tubular wall by melting a fusible metal coating provided on at least one of the parts to be brazed.

• la figure 1 est une vue partielle en coupe longitudinale d'un échangeur de chaleur, prise selon la ligne I-I de la figure 2 ;
• la figure 2 est une vue partielle en coupe selon la ligne II-II de la figure 1 ;
• la figure 3 représente un sous-ensemble de cet échangeur en vue de dessus par rapport à la figure 1 ;
• les figures 4 et 5 sont des vues analogues aux figures 1 et 2 respectivement, relatives à un échangeur de chaleur selon l'invention ;
• la figure 6 représente une cloison transversale de l'échangeur de chaleur des figures 4 et 5 ;
• les figures 7 et 8 sont des vues analogues aux figures 1 et 2 respectivement, relatives à un autre échangeur de chaleur selon l'invention ;
• la figure 9 représente le sous-ensemble formé par les cloisons transversales et la pièce profilée en forme de gouttière de l'échangeur de chaleur des figures 7 et 8, cette dernière étant vue en coupe selon la ligne IX-IX de la figure 10 ; et
• la figure 10 est une vue en coupe selon la ligne X-X de la figure 9.

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 in longitudinal section of a heat exchanger, taken along line II of Figure 2;
• Figure 2 is a partial sectional view along the line II-II of Figure 1;
• FIG. 3 represents a sub-assembly of this exchanger in top view relative to FIG. 1;
• Figures 4 and 5 are views similar to Figures 1 and 2 respectively, relating to a heat exchanger according to the invention;
• Figure 6 shows a transverse partition of the heat exchanger of Figures 4 and 5;
• Figures 7 and 8 are views similar to Figures 1 and 2 respectively, relating to another heat exchanger according to the invention;
• FIG. 9 represents the sub-assembly formed by the transverse partitions and the profiled part in the form of a gutter of the heat exchanger of FIGS. 7 and 8, the latter being seen in section along the line IX-IX of FIG. 10; and
• FIG. 10 is a sectional view along line XX of FIG. 9.

The heat exchanger partially shown in Figures 1 and 2, intended in particular to serve as a condenser in an air conditioning installation of the passenger compartment of a motor vehicle, comprises a fluid box 1 formed by a tubular wall 2 closed in the vicinity from its ends by two transverse partitions 3a and 3b to define an interior space subdivided by intermediate transverse partitions 4a, 4b into several compartments 5a, 5b, 5c, 5d (the references 5b and 5c correspond to two different compartments or to the same compartment according to whether or not there is at least one other partition, not shown, between the partitions 4a and 4b).

The tubular wall 2 has a multiplicity of openings 6 in each of which engages a tube 7, the cross section of which is elongated in the transverse direction of the fluid box, the tubes 7 being parallel to each other and perpendicular to the longitudinal direction of the fluid box. An open end 8 of each of the tubes 7 is located inside the fluid box 1, the opposite end may be inside another fluid box not shown, similar to the fluid box 1 and extending parallel thereto. Interleaves 9 constituted by strips of metal sheets curved substantially in the form of a sinusoid are placed in the gaps between the tubes 7 (or between a tube 7 and an end plate 10) to come into thermal contact with the tubes.

According to the invention, the partitions 3 and 4, all identical to each other and having the shape of circular disks, have a central circular opening 11 in which an elongate cylindrical rod 12 is engaged practically without play, common to all the transverse partitions, this rod forming a connecting piece between the partitions. The rod 12 is flattened by a mechanical operation in zones 13 adjacent to the partitions, on either side of each of these, to form radial bulges, as shown in FIG. 3, transversely to the direction of the flattening. These bulges immobilize the partitions 3 and 4 in the longitudinal direction of the rod.

The subassembly thus formed is introduced, during the assembly of the heat exchanger, inside the tubular wall 2 by one of the open ends thereof, and slides longitudinally, the edge of the partitions 3 and 4 sliding against the internal surface of the wall 2, until the partitions reach the positions which they must occupy in the finished heat exchanger. The tubes 7 are then introduced through the openings 6, which may have been made either before or after the installation of the sub-assembly 3, 4, 12, until their ends 8 abut against the rod 12 .

The seal between the outer surface of the tubes 7 and the openings 6 on the one hand, between the edge of the partitions 3 and 4 and the internal surface of the tubular wall 2 on the other hand, is obtained by brazing by means of a fusible metal coating which is melted by heating the assembled heat exchanger. This coating is preferably provided on the outer surface of the tubular wall 2 for its connection with the tubes, and on the partitions for their connection with the tubular wall. This prevents the presence of such a coating on the internal surface of the tubular wall, which could cause partial closure of the ends of the tubes.

The general structure and the method of assembly of the heat exchangers illustrated in FIGS. 4 to 10 are the same as those of the heat exchanger of FIGS. 1 to 3, and the identical elements are designated by the same reference numbers. Only the transverse partitions and the profiled part differ from one embodiment to another and will be described below.

In the example of FIGS. 4 to 6, the cylindrical rod 12 of the first example is replaced by a bar 112 of rectangular cross section, having a multiplicity of notches 113 regularly spaced in its longitudinal direction, all adjacent to the same narrow edge 114 of the bar 112, extending over the entire width of the cross section thereof and thus giving it the appearance of a rack. These notches are limited by aces surfaces perpendicular to the longitudinal direction of the bar.

The transverse end partitions 103a, 103b and the intermediate transverse partitions 104 (only one of which is shown in FIG. 4) are circular disks whose thickness is substantially equal to the width of the notches 113. Each of these partitions has ( see Figure 6) a radial notch 115 extending over the entire thickness of the partition. The notch 115 is symmetrical with respect to an axial plane 116 of the partition and has a uniform width corresponding to that of the bar 112. The sum of the depths of a notch 113 and a notch 115 is substantially equal to the length of the rectangular section of the strip 112, so that each partition can be fitted onto the bar, at the level of one of the notches 113, as shown in FIGS. 4 and 5, the profile of the bar not projecting with respect to the circular contour defined by the partitions 103, 104. The sub -assembly formed by the bar 112 and the partitions thus associated is mounted in the heat exchanger in the same way as the sub-assembly 3, 4, 12 of the first embodiment, the tubes 7 coming to bear on the edge 114 of the bar.

In the example of Figures 7 to 10, the connecting piece has a gutter shape whose cross section represents a semicircle. This gutter has a multiplicity of openings 213 aligned in its longitudinal plane of symmetry and regularly spaced from each other. The end transverse partitions 203a, 203b and the intermediate transverse partitions 204a, 204b, identical to each other, each have the form of a circular disc whose edge has a recess in two parts 217a, 217b symmetrical to one another by with respect to an axial plane 216 and separated from each other by an unhollowed-out zone 215 extending over a short arc length on either side of the plane 216. The recess 217a, 217b and the zone 215 extend in total over a half-circumference, and the depth of the recess corresponds to the thickness of the gutter 212.

Each partition 203, 204 can therefore be placed in the gutter so that the projecting zone 215 engages in an opening 213, the profile of the gutter coming to fill the recess 217a, 217b to reconstruct the circular outline of the partition. The openings 213 can be slightly flared towards the outside of the gutter so as to allow mutual riveting by deformation of the projection 215.

During the establishment of the sub-assembly formed by the gutter 212 and the partitions 203, 204, the outer surface of the gutter comes to bear on the internal surface of the tubular wall 2, in the half-circumference of this- here opposed to openings 6. The ends 8 of the tubes 7 abut against the longitudinal edges 218 of the gutter.

In the last two embodiments, only part of the notches 113 or openings 213 is used to receive the partitions, depending on the number and the mutual spacing of these.

Claims (9)

1. A heat exchanger comprising at least one fluid header (1) having an elongate tubular wall (2) and at least two transverse baffles (3, 4) carried thereby and fixed to a connecting member (12) which is elongated in the direction of the axis of the tubular wall, together with a multiplicity of parallel tubes (7) penetrating into the fluid header through apertures (6) which are formed in the tubular wall, characterised in that the connecting member is a bar (112) having slots (113), spaced apart from each other in the longitudinal direction, for receiving the transverse baffles, each baffle (103, 104) also having a slot (115) for receiving the bar, with the latter coming substantially into contact with the tubular wall in a region which is diametrically opposed to the apertures through which the tubes pass.
2. A heat exchanger according to Claim 1, characterised in that the transverse baffles comprise two endmost baffles (3a, 3b) which, together with the tubular wall, define the internal space of the fluid header.
3. A heat exchanger according to Claim 1 or Claim 2, characterised in that the transverse baffles include at least one intermediate baffle (4a, 4b) dividing the fluid header into at least two compartments (5a, 5b, 5c, 5d), into each of which some of the tubes are open.
4. A heat exchanger according to one of the preceding Claims, characterised in that the ends (8) of the tubes abut against the connecting member.
5. A heat exchanger according to one of the preceding Claims, characterised in that the peripheral edges of the transverse baffles and/or the tubes are brazed to the tubular wall.
6. A heat exchanger according to one of Claims 1 to 5, characterised in that the bar (212) is in the form of a cradle, having a transverse cross section in the form of an arc of a circle and having transverse openings (213) which are spaced apart from each other in its longitudinal direction, with each baffle having a recess (217a, 217b) along its periphery, with the depth and circumferential extent of the recess corresponding to the thickness and to the arc length of the cradle, the said recess being interrupted by a radial projecting element (217) which engages in an opening (213) of the cradle so as to secure the baffle to the cradle, with the latter being in engagement on the tubular wall in a direction diametrically opposed to the apertures through which the tubes pass.
7. A heat exchanger according to one of Claims 1 to 6, characterised in that the connecting member has a multiplicity of slots or openings spaced apart at regular intervals, with only some of them being associated with transverse baffles.
8. A method of making a heat exchanger according to any one of the preceding Claims, in which the connecting member (12) carrying the transverse baffles (3, 4) is introduced through an open end of the tubular wall, and is caused to slide longitudinally until the baffles reach their final positions, prior to introduction of the ends of the tubes (7) into the fluid header through the apertures (6) of the tubular wall.
9. A method according to Claim 8, characterised in that the peripheral edges of the transverse baffles and/or tubes are brazed to the tubular wall by melting a meltable metallic coating which is provided on at least one of the components to be brazed together.

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