EP1285212B2 - Manifold block for brazed heat exchanger - Google Patents

Description

The invention relates to heat exchangers, especially for a motor vehicle.

It relates more particularly to a header for a brazed heat exchanger comprising walls which define a chamber, one of the walls of the chamber being provided with an opening, a pipe being connected to this opening.

In a collector box of this kind, the collector plate, which is also called a perforated plate, has a multiplicity of holes in which the tube ends which constitute the heat exchanger bundle are received. To these tubes are associated fins contributing to increase the heat exchange surface. The collector plate is formed by a wall which delimits a chamber communicating with the tubes to allow the circulation of a heat transfer fluid in the beam. One of the walls of the chamber is provided with at least one tubing to allow the entry or exit of the coolant.

Brazed heat exchangers comprise a bundle mounted between two manifolds. The beam is formed of a multiplicity of tubes arranged parallel to each other and alternating with spacers. These spacers are of corrugated type, that is to say that they are formed from a deformed metal strip to form corrugations. Thus, a spacer disposed between two adjacent tubes comes into respective contact with the two tubes by end regions of the corrugations.

Usually, the heat exchanger further comprises two cheeks, also called sleepers, which frame the beam and are arranged parallel to the tubes. The different parts are formed of a metal material externally coated with a solder alloy.

After assembly, the different parts of the exchanger are brazed by passing through an oven. It is therefore necessary to temporarily hold them in place so that they can not move each other during their passage in the oven before being permanently joined together. In particular, it is necessary that the pipes do not move relative to the wall of the chamber.

Currently (see for example US Patent 4026456 ), the provisional fixing of the tubes is obtained by crimping them on the collector box. Such an operation requires adapted tools and a recovery of the box. It is therefore expensive to perform.

The present invention aims to provide a manifold, and a heat exchanger comprising such a box, which allow rapid and inexpensive temporary fixation of the tubing in an opening of a wall of the manifold.

This result is obtained thanks to a header box according to claim 1.

The tubing is introduced manually or automatically into the opening, the lug or lugs being placed opposite the corresponding notches made at the periphery of the opening. Then the tubular is angularly rotated by a certain angle so that the lug or the lugs are no longer facing the notches. Thus the tubing is temporarily maintained on the manifold box stably during the passage of the exchanger in the oven.

Advantageously, the tubing comprises at least two lugs. Preferably, the tubing comprises three lugs arranged at 120 ° from each other. The opening will then also include three notches arranged at 120 ° from each other. Preferably, the number of notches is equal to the number of lugs of the tubing, but this characteristic is not essential. The number of notches can also be a multiple of the number of lugs. One can imagine for example that the opening has six notches arranged at 60 ° from one another, which would limit the angle of rotation required to introduce the lugs in the notches.

Frequently, the tubing is bent and must extend in a given direction to be fitted with a flexible conduit. In this case, it is necessary to respect a precise angular orientation of the tubing with respect to the manifold. If the tubing is mounted manually, the wall of the chamber which has the opening is preferably provided with a stop which limits the rotation of the tubing by cooperation with a pin.

• Des moyens sont prévus pour immobiliser la tubulure dans une position finale de son mouvement de rotation, par serrage dans la direction de son axe de rotation.
• Lesdits moyens d'immobilisation comprennent une rampe formée sur la face interne de ladite paroi de manière à coopérer avec un ergot, et une saillie radiale formée sur la tubulure en regard de la face externe de la paroi de manière à serrer progressivement la paroi munie de la rampe entre ladite saillie et l'ergot, à l'approche de ladite position finale.
• Ladite butée est disposée de manière à arrêter ledit mouvement de rotation dans ladite position finale.
• La face interne de la paroi présente une saillie juxtaposée à une encoche dans la direction circonférentielle de manière à coopérer avec un ergot ayant franchi cette encoche pour permettre un mouvement de rotation seulement dans un sens déterminé.

Other optional features of the invention are set out below:

• Means are provided for immobilizing the tubing in a final position of its rotational movement, by clamping in the direction of its axis of rotation.
• Said immobilization means comprise a ramp formed on the inner face of said wall so as to cooperate with a lug, and a radial projection formed on the tubular facing the outer face of the wall so as to gradually tighten the wall provided with the ramp between said projection and the lug, at the approach of said final position.
• Said stop is arranged to stop said rotational movement in said final position.
• The inner face of the wall has a projection juxtaposed with a notch in the circumferential direction so as to cooperate with a lug having crossed this notch to allow rotational movement only in a given direction.

• la figure 1 est une vue partielle en perspective d'une boîte collectrice pour un échangeur de chaleur selon l'invention, comprenant une tubulure en cours d'assemblage ;
• la figure 2 est une autre vue partielle en perspective analogue à la figure 1 ;
• les figures 3 et 4 sont des vues agrandies analogues à la figure 2 montrant la tubulure respectivement avant et après assemblage ;
• la figure 5 est une vue en coupe longitudinale d'une tubulure, montrant également en coupe une partie de la paroi de la boîte collectrice dans l'ouverture de laquelle l'extrémité de la tubulure vient d'être introduite ;
• la figure 5a est un détail agrandi de la figure 5 ;
• la figure 6 est une vue analogue à la figure 5a, montrant la tubulure à la fin de son mouvement de rotation ;
• la figure 7 est une vue en perspective montrant la tubulure dans sa position finale et la partie adjacente de la paroi de la boîte collectrice ; et
• la figure 8 est une vue en élévation de la région de la paroi représentée sur les figures 5 à 7 comportant l'ouverture.

Other features and advantages of the present invention will become apparent upon reading the following description of an exemplary embodiment given by way of illustration with reference to the appended figures. In these figures:

• the figure 1 is a partial perspective view of a header for a heat exchanger according to the invention, comprising a tubing during assembly;
• the figure 2 is another partial perspective view analogous to the figure 1 ;
• the Figures 3 and 4 are enlarged views similar to the figure 2 showing the tubing respectively before and after assembly;
• the figure 5 is a longitudinal sectional view of a tubing, also showing in section a portion of the wall of the manifold in the opening of which the end of the tubing has just been introduced;
• the figure 5a is an enlarged detail of the figure 5 ;
• the figure 6 is a view similar to the figure 5a , showing the tubing at the end of its rotational movement;
• the figure 7 is a perspective view showing the tubing in its final position and the adjacent portion of the wall of the header; and
• the figure 8 is an elevational view of the region of the wall shown on the Figures 5 to 7 having the opening.

On the figure 1 , the manifold comprises a first portion 10 and a second portion 12, each formed from a metal sheet, preferably aluminum, which is shaped by conventional cutting and stamping operations.

The first part 10 has a bottom 14 which is generally flat and of elongated rectangular shape. This bottom 14 is intended to form the collector plate, also called "plate with holes", of the manifold. This bottom comprises for this purpose a plurality of spaced holes 16 of elongate shape for receiving tubes 18 forming part of the beam of the heat exchanger. In the example described, these are flat tubes 18 between which fins 20 are arranged in the form of corrugated inserts.

The portion 10 further comprises two lateral flanks 22 folded facing each other, and which are generally planar and parallel to each other. These flanks are connected substantially perpendicular to the bottom 14 by two fold lines 24 which are parallel to each other. The lateral flanks 22 comprise in their central part respective extensions 26 and 28. The extension 26 has an opening 30 while the extension 28 is completely closed. The opening 30 is circular in shape and is intended to allow the adaptation of a tubular 32 of circular section.

The second part 12 fits on the lateral flanks 22 so that these two parts jointly delimit a closed volume which communicates with the tubes 18 of the beam. It will be understood that it is thus possible to perform in a single brazing operation a heat exchanger comprising a beam formed by a multiplicity of tubes and fins, together with one or two manifolds.

We have shown on the figure 2 a perspective view of the respective extensions 26 and 28 of the lateral flanks 22. It is noted that the opening 30, formed in the extension 26, has notches 34, which are three in the embodiment shown. The notches 34 are arranged at 120 ° from each other. The end of the tubing 32 which engages in the opening 30 has three lugs 36, also arranged at 120 ° from each other. These lugs form protuberances protruding outwardly of the tubing.

When the lugs 36 are opposite the notches 34, it is possible to introduce the end of the tubing into the opening 30 as represented by the arrow F1 on the figure 3 . The tubing 32 comprises a flange 40 which limits the penetration of the tubing into the opening 30. When the flange 40 bears against the wall 26 of the manifold, the tubing is rotated in one direction or in the other. a certain angle, for example 10 or 20 ° (as shown by the arrow F2 on the figure 4 ), so that the lugs are no longer opposite the notches 34. The pipe is thus held firmly enough on the manifold box so that it is possible to perform the brazing operation without it being possible. moves. In particular, the lugs 36 are shaped such that a slight tightening of the tubing on the wall 26 is obtained.

However, it often happens that the tubular 32, instead of being straight cylindrical as shown in the example, has a bent shape. In this case, it must be arranged in a precise angular orientation relative to the manifold to connect to a flexible pipe of the fluid circulation circuit. If the tubing is introduced by a robot, the robot can be adjusted to provide a proper angular orientation and no further action is necessary. If the tubing is introduced manually by an operator, the wall 26 preferably include a boss 42 ( Figures 3 and 4 ), obtained for example by punching, and forming a stop which limits the rotational movement of the tubing relative to the manifold. When one of the lugs 36 abuts against the boss 42, the appropriate angle of rotation is obtained.

It is important that the notches 34 are small in size so that they can be filled by the solder alloy during the soldering operation.

The Figures 5 to 8 illustrate a variant of the heat exchanger according to the invention, in which means are provided for clamping the tubing in the final position of its rotational movement, defined by the abutment of the wall, so as to avoid an inversion of this movement. On the Figures 7 and 8 for clarity, only a square-shaped region of the wall, concentric with the opening, is shown.

The tubing 50 is bent and its end 52 which engages in the manifold here has a single lug 54, associated with a single notch 56 of the generally circular opening 58 through which the tubing. A stop 60 similar to the stop 42 of the Figures 3 and 4 is formed at the edge of the opening 58, at an angular distance from the notch 56, about the axis A of the opening, slightly greater than 90 ° so as to limit the rotation of the tubing at an angle of 90 ° counterclockwise, as seen from inside the manifold, according to arrow F of the figure 8 . In addition, a ramp 62 is juxtaposed to the stop 60, at an angular distance of 90 ° with respect to the notch 56. The ramp 62, like the stop 60, is produced by deformation, in the direction of the axis A. of the wall 64 of the header, in which the opening 58 is formed.

We see on the figure 5 , and even better on the figure 5a , that the gap 66 which axially separates the lug 54 from the flange 68, similar to the flange 40 of the Figures 1 to 4 , tubing 50 has a width greater than the thickness of the wall 64, so that the tubing can rotate freely about the axis A after the lug has been engaged through the notch 56. After a rotation at an angle close to 90 °, the lug comes opposite the ramp 62, which has vis-à-vis thereof a surface 70 inclined so as to move progressively away from the plane of the outer face 72 turned towards the flange 68, of the wall 64, up to a maximum distance slightly greater than the width of the gap 66 so as to effect an axial clamping of the wall 64 between the lug 54 and the flange 68, after a rotation of 90 °, while the lug 54 abuts in the circumferential direction on the stop 60, which protrudes up to a distance from the wall 72 substantially greater than the width of the gap 66. The continuation of the rotational movement is thus prevented by the stop 60, while a movement in the opposite direction is forbidden by the axial clamping of the ramp 62, which also avoids a perpendicularity defect between the axis of the tubing and the plane of the wall 72.

A projection 74 similar to the stop 60 is made by deformation of the wall 64, in a position slightly offset relative to the notch 56 in the opposite direction to that of the rotational movement of the tubing. This projection cooperates with the lug 54 to prevent rotational movement of the tubing in the wrong direction during its manual placement.

It is understood that the clamping means comprising the ramp 62 and the keying means comprising the projection 74, although incorporated herein in the same embodiment, can be implemented independently of each other. In addition, one and / or the other can be used in combination with a multiplicity of pins as described in the first embodiment.

The heat exchanger of the invention can be used in particular to constitute an engine cooling radiator or a heating radiator of the passenger compartment of a motor vehicle.

Claims (11)

1. Manifold block for a brazed heat exchanger comprising walls (12, 14, 22) which delimit a chamber, one of the walls (22) of the chamber being provided with an opening (30), a pipe (32) being connected to the opening (30), characterized in that:

   a. the said walls are defined by a first (10) and a second (12) part, each formed of a sheet of metal which is shaped using conventional cutting and pressing operations, said first part comprising a generally flat bottom (14) of elongate rectangular shape, provided with holes (16) intended to accept tubes (18) and two generally flat and mutually parallel side walls (22) bent up facing each other, the said side walls meeting the bottom (14) substantially at right angles along two bend lines (24) which are mutually parallel, the said lateral side walls comprising respective extension in their central part, the said opening (30) being provided in one of the said extensions,

   b. the said pipe (32) comprises at least one lug (36),

   c. the opening (30) comprises at least one notch (34) that the lug or lugs (36) can enter so that, during brazing, the pipe can be held temporarily in the opening by the lug or lugs once the pipe has been turned in the opening.
2. Manifold block according to Claim 1, characterized in that the number of notches (34) is equal to the number of lugs (36).
3. Manifold block according to Claim 1, characterized in that the number of notches (34) is a multiple of the number of lugs (36).
4. Manifold block according to one of the preceding claims, characterized in that the pipe (32) comprises at least two lugs (36).
5. Manifold block according to one of the preceding claims, characterized in that the pipe (32) comprises three lugs (36) positioned 120° apart.
6. Manifold block according to one of the preceding claims, characterized in that the wall of the chamber that comprises the opening (30) is provided with an end stop (42) that limits the rotation of the pipe (32) by interfacing with a lug (36).
7. Manifold block according to one of the preceding claims, characterized in that means (62) are provided for immobilizing the pipe in a final position with its rotational movement, by clamping in the direction of its axis of rotation (A).
8. Manifold block according to Claim 7, characterized in that the said immobilizing means comprise a ramp (62) formed on the internal face of the said wall (64) to interface with a lug (54), and a radial projection (68) formed on the pipe facing the external face (72) of the wall so as to gradually clamp the wall equipped with the ramp between the said projection and the lug as the said final position is approached.
9. Manifold block according to Claim 8, associated with Claim 6, characterized in that the said end stop (60) is positioned in such a way as to stop the said rotational movement in the said final position.
10. Manifold block according to one of the preceding claims, characterized in that the internal face of the wall has a projection (74) juxtaposed with a notch (56) in the circumferential direction so as to interface with a lug which has passed through this notch so as to allow a rotational movement in just one set direction.
11. Heat exchanger characterized in that it comprises at least one manifold block according to one of the preceding claims.

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