EP0145574A2 - Method of crimping a heat exchanger end plate onto a header box - Google Patents

Abstract

Tube heat exchanger (6) and dissipators (7), the tubes of which open into a collecting plate (5) covered by a water box (1) set by a rising edge (9), characterized in that the rising edge ( 9) has on its periphery a line of least resistance (11), in that stiffening means (12, 13) are provided in the rising edge (9) above the line of least resistance (11) and that said stiffening means (12, 13) are at least partially folded over a peripheral rim (4) of the water box in a position for which a heel (3) of this water box compresses a seal.

Description

The present invention relates to a new method for crimping a water box into a header plate of a heat exchanger so that the water box compresses a deformable seal which must ensure a perfect seal between the header plate and the water box .

In the known technique, the crimping of the water box is most often carried out by means of tabs which project from the peripheral rising edge of the collecting plate, these tabs being folded over a projecting rim which the water box has.

The above technique is used in particular in patent FR-79 09343, in patent FR-83 05785 as well as in patent FR-1 039 911. In certain cases, the folded legs are reinforced by ribs. This is the subject of patent application EP-A-0 054 815.

This widely used arrangement has the drawback that the tabs work on bending and that, when folded, they can, in certain cases, produce deformations of the rising edge of the collector plate from which they protrude, these deformations being able to affect the seal between said collector plate and the water box.

To remedy this drawback, the Applicant has proposed in patent FR - 69 24782 a water box-collector plate connection by providing stapling members protruding in the peripheral edge of the box. water and by engaging these stapling members in the openings of the rising edge of the collector plate. Similar arrangements have also been described in patent FR-79 29548.

This arrangement is satisfactory because the metal works under tension, but the installation of the water box sometimes poses relatively delicate problems. Indeed, depending on the nature of the metal of the collector plate, it is possible, if this metal is elastic, to carry out a snap fitting but, if the metal is not elastic, it is first of all necessary to flare the rising edge of the collector plate then tighten it against the water box while keeping this water boot under pressure.

The present invention relates to an embodiment which makes it possible to obtain the same advantageous results as those obtained by the introduction of protruding stapling members of the water box into the openings of the rising edge of the collecting plate while allowing easy placement of the water box, regardless of the nature of the metal which constitutes the collecting plate.

According to the invention, the method for crimping a header plate of a heat exchanger on a water boot in which there is provided a peripheral rising edge to fit an extra thickness delimited by the water box is characterized in that 'is created in the peripheral edge of the collector plate, substantially at the edge of the water box, a line of least resistance, in that the portion of the rising edge of the collector plate extending above is stiffened of the line of least resistance and in that the stiffened part of the edge is folded back, at least partially amount of the collector plate on the edge of the water boot.

The invention also extends to a heat exchanger obtained in accordance with the above method. According to this second arrangement of the invention, the heat exchanger of the tube and dissipator type, the tubes of which open into at least one collecting plate which is covered by a water box crimped by a peripheral rising edge of the collecting plate. is characterized in that the rising edge of the collector plate has, over at least most of its periphery, a line of least resistance, in that stiffening means are provided in the rising edge above the line of lower resistance and in that said stiffening means are, at least partially folded over a peripheral rim of the water box in a position for which a heel of this water box compresses a seal.

Various other characteristics of the invention will also emerge from the detailed description which follows.

• La fig. 1 est une perspective partielle, en partie éclatée, d'un échangeur de chaleur faisant application de l'invention.
• La fig. 2 est une coupe vue sensiblement suivant la ligne II-II de la fig. 1.
• La fig. 3 est une coupe vue sensiblement suivant la ligne III-III de la fig. 1.
• La fig. 4 est une perspective partielle, analogue à la fig. 1, illustrant une caractéristique supplémentaire.
• La fig. 5 est une coupe transversale schématique montrant une position particulière d'une plaque collectrice de l'échangeur et de la boite à eau avant l'exécution d'une passe de travail.
• La fig. 6 est une coupe schématique illustrant la passe de travail par laquelle la plaque collectrice est sertie sur la boîte à eau.
• La fig. 7 est une coupe transversale, analogue à la fig.5, montrant la relation entre la plaque collectrice et la botte à eau après sertissage.
• La fig. 8 est une perspective d'une variante.

Embodiments of the object of the invention are shown, by way of nonlimiting examples, in the accompanying drawing.

• Fig. 1 is a partial perspective, partly exploded, of a heat exchanger applying the invention.
• Fig. 2 is a section seen substantially along line II-II of FIG. 1.
• Fig. 3 is a section seen substantially along the line III-III of fig. 1.
• Fig. 4 is a partial perspective, similar to FIG. 1, illustrating an additional feature.
• Fig. 5 is a schematic cross section showing a particular position of a header plate of the exchanger and the water box before the execution of a work pass.
• Fig. 6 is a schematic section illustrating the working pass by which the collector plate is crimped onto the water box.
• Fig. 7 is a cross section, similar to FIG. 5, showing the relationship between the collector plate and the water boot after crimping.
• Fig. 8 is a perspective of a variant.

In the drawing, 1 denotes a water box of a heat exchanger. The boot 1 is made of molded material, for example of synthetic material or metal, and delimits, at its lower part, an extra thickness 2 forming on its bottom a heel 3 and on its top a rim 4. The drawing shows that the extra thickness 2 is formed over the entire periphery of the water boot.

The water box is intended to cover a metal collecting plate 5 into which open tubes 6 which are tightly connected thereto and between which are, for example, heat sinks 7. The collecting plate defines a groove over its entire periphery or gutter 8.

The peripheral rising edge 9 of the collector plate has, substantially at the position which the rim 4 of the water box must occupy, holes or openings 10 intended to create a line of least resistance designated by 11 in the drawing.

Corrugations 12 are formed above the line of least resistance 11, these corrugations leaving free between them segments 13 which lie in the same vertical plane as that passing through the internal face of the rising edge 9.

Figs. 2 and 3 thus show that the corrugations 12 leave the groove 8 formed by the collector plate completely free, which allows an easy installation of the additional thickness 2 of the water box 1 in the groove 8 after having disposed there a flexible seal. deformable 14. The existence of the corrugations 12 has the effect of stiffening the upper part of the rising edge 9 above the line of least resistance 11.

To crimp the collector plate 5 on the water box, a tool designated as a whole by 15 in FIG. 6, this tool delimiting a passage 16 for the tubes 6 and dissipators 7 and forming, at its upper part, a shoulder 17 above which extend crimp walls 18. The height of crimp walls 18 is greater than the height of the rising edge 9 of the collector plate.

As illustrated in the drawing, the collector plate to which the tubes 6 and dissipators 7 are fixed is engaged in the tool 15 until the corrugations 12 abut against the top 19 of the tool.

Then put in place, if not already done, the flexible seal 14 in the groove 8 of the collector plate and then engage the water box 1 so that the heel 3 which it presents comes to bear on the seal 14. Next, the pressure on the water box 1 is directed along the arrow f ₁ . This pressure has first of all the effect of compressing the seal 14 in the bottom of the groove 8 then the pressure continuing to be exerted there is a progressive deformation of the part of the rising edge 9 at the height of the line of least resistance 11. This deformation is caused by the corrugations 12 which slide along the crimping walls 18 and therefore cause the segments 13 to tilt towards the top of the flange 4. The deformation occurs until the external wall of the corrugations 12 is brought into a substantially vertical plane. The corrugations 12 thus have a cam effect.

In this arrangement, the holes or openings 10 delimiting the line 11 of least resistance cover the lateral edge of the rim 4 which is thus partially at least embedded while the segments 13 are folded over the top of said rim 4.

Figs. 4 and 8 illustrate a slight variant according to which notches 20 are formed in the rim 4 to delimit, between them, teeth 21 which coincide with the holes 10 of the collector plate. It is advantageous that the holes 10 have a diameter or a width if they are oblong, rectangular or trapezoidal (FIG. 8) greater than the width of the teeth 21 to compensate for the manufacturing tolerances existing between the water box and the collector plate . The line of least resistance 11 is then situated substantially at the level of the base of the teeth 21.

Since the teeth 21 coincide with the holes 10 at the end of the crimping operation, said teeth are inserted into the holes 10 and, consequently, the connection by embedding is further reinforced.

Although this is not necessary, it is advantageous to facilitate the crimping operation to provide slots or notches 22, for example at the four corners of the rising edge 9 of the collector plate.

The invention is not limited to the embodiments shown and described in detail, since various modifications can be made thereto without departing from its scope. In particular, the slots or notches 22 can be replaced by corrugations which are tightened at the time of crimping. Likewise the line of least resistance can be delimited other than by lights; it is possible that it is formed by a thinned part, for example a continuous or discontinuous groove of the collector plate. It is also possible that the lights are connected by a part of less resistance, particularly when the water box forms teeth 21.

Claims (13)

1 - Method for crimping a header plate of a heat exchanger on a water box in which a peripheral rising edge is provided to fit an extra thickness that delimits the water box, characterized in that the part is stiffened from the rising edge (9) of the collector plate which must extend in the assembled state at least partly above the rim (4) of the water boot (1) and in that this flap is at least partially folded down stiffened part of the rising edge of the collecting plate on the rim (4) of the water box. 2 - Method according to claim 1, characterized in that one creates in the peripheral edge (9) of the collector plate a line of least resistance (11). 3 - Method according to one of claims 1 or 2, characterized in that the upper part of the rising edge of the collector plate is stiffened by forming, in this part, undulations projecting outwards and delimiting between them segments (13) which extend vertically. 4 - Method according to one of claims 1 to 3, characterized in that one realizes the line of least resistance (11) by forming holes or holes (10) in the rising edge of the collector plate at a level for which the edge of the rim (4) of the water box or the top of the legs (21) of this rim (4) is embedded in said holes or slots (10). 5 - Method according to one of claims 1 to 3, characterized in that teeth (21) are formed in the water box (1) in correspondence with at least some of the holes or lights (10) delimiting the line of least resistance, said holes or lights being of round, oblong, rectangular or trapezoidal shape and said teeth having a narrower width than the holes or lights. 6 - Method according to one of claims 1 to 5, characterized in that to fold the stiffened part of the rising edge of the collector plate, this rising edge is placed in a tool having crimping walls whose spacing corresponds to l spacing of the external face of the different planar sides of the rising edges of the collecting plate, in that a deformable seal (14) is placed in the collecting plate, in that the water box is placed so that a heel (3) which it has on said seal, in that pressure is exerted on the water box so that the seal is first deformed then that the projecting undulations (12) and the segments (13 ) placed between them are then folded towards a flange (4) of the water boot at the same time as the deformable seal (14) continues to be kept under pressure. 7 - Heat exchanger of the tube and dissipator type, the tubes of which open into at least one collecting plate which is covered by a water box crimped by a peripheral rising edge of the collecting plate, characterized in that the rising edge ( 9) of the collector plate has, over at least most of its periphery, a line of least resistance (11), in that stiffening means (12, 13) are provided in the rising edge (9) au- above the line of least resistance (11) and in that said stiffening means (12, 13) are at least partially folded over a peripheral rim (4) of the water box in a position for which a heel (3) of this water box compresses a seal (14). 8 - Exchanger according to claim 7, characterized in that the stiffening means consist of corrugations (12) separated by segments (13). 9 - Exchanger according to one of claims 7 or 8, characterized in that the line of least resistance (11) is delimited by holes or lights (10). 10 - Exchanger according to one of claims 7 or 9, characterized by teeth (21) formed by the water box opposite the holes or lights (10) of the rising edge of the collector plate. 11 - Exchanger according to one of claims 7 to 10, characterized in that the teeth (21) of the water box are delimited by notches (20) for the passage of the segments (13) during the insertion of the teeth (21) in the holes or lights (10). 12 - Exchanger according to one of claims 7 to 11, characterized in that the width of the teeth (21) is smaller than the diameter or the width of the openings (10). 13 - Exchanger according to one of claims 7 to 12, characterized in that at least one slot, notch or corrugation (22) is provided in each rising edge to extend to the vicinity of the line of least resistance ( 11).

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