EP3198212B1 - Header plate for a heat exchanger, header box and heat exchanger - Google Patents

Description

The present invention relates to a collector plate (also called collector) of a motor vehicle heat exchanger, for example for engine cooling radiator, for air conditioning condenser, for charge air cooler, as well as a manifold box. and a heat exchanger. The present invention relates in particular to a header plate as defined by the preamble of claim 1, and as disclosed by JP 10232097 .

We already know, from the document JP2005 / 308366 , a header plate for a heat exchanger, comprising a wall provided with orifices, intended to be crossed by tubes arranged in a row in a longitudinal direction. This plate has a central portion for receiving the tubes which is curved inward or outward.

We know that the curvature of the collector plates is intended to avoid as much as possible the deterioration of the exchanger caused by local thermal differences which strongly constrain the tube and stress the junction between the collector plate and the tubes, in particular on the external rays of the tube. This junction can be materialized by a joint or by brazing or even a direct weld between the tube and the plate. In the long run, the junction may end up being no longer watertight, which puts the exchanger out of service. A high fluid circulation pressure inside the exchanger is of course an aggravating factor of this phenomenon.

Among the many solutions already proposed, none has so far completely eliminated this problem of deterioration of the junction between collector plate and tube.

The object of the invention is to provide a solution which overcomes these drawbacks, in particular by reducing the constraints which apply to the tube.

• ladite paroi présente, en section transversale, un profil constitué d'une portion centrale et de deux portions latérales,
• les portions latérales suivent globalement une première courbe d'un premier rayon de courbure,
• la portion centrale suit globalement une seconde courbe d'un second rayon de courbure, plus petit que le premier rayon de courbure.

The invention firstly relates to a header plate for a heat exchanger according to claim 1, comprising a wall provided with orifices, intended to be traversed by tubes arranged in a row in a longitudinal direction, characterized in that :

• said wall has, in cross section, a profile consisting of a central portion and two lateral portions,
• the lateral portions generally follow a first curve with a first radius of curvature,
• the central portion generally follows a second curve with a second radius of curvature, smaller than the first radius of curvature.

Preferably, by "smaller than" is meant representing less than 80% of the reference value. So, preferably, the second radius of curvature should be less than 80% of the first radius of curvature.

$$\mathrm{0,05}<\mathrm{H}2/\mathrm{TW}<\mathrm{0,3}$$

According to the invention, at least one of the orifices has, in a direction perpendicular to the longitudinal and transverse directions, an oblong projection with a major axis TW, (also called “width of the orifice for passage of the tube in the manifold”) and, relative to a plane passing through longitudinal edges of the wall, the height of the lateral portions is H1 and the height of the central portion is H2, and the ratio between the heights H1, H2 and the major axis TW respects the following inequalities: $$0.05<\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">H</figure-callout>}1/\mathrm{TW}<0.2$$

$$0.05<\mathrm{H}2/\mathrm{TW}<0.3$$

By respecting these recommendations, a heat exchanger is obtained in which the stress exerted on the tube is reduced as much as possible.

Preferably, the major axis (TW) of a tube (or passage width of the tube) is between 10 mm and 100 mm.

In a particular embodiment, the collar intended to cover a part of the wall of the tube passing through the wall through this orifice, projects outwards from the manifold. The function of such a collar is to improve the seal between the tube and the collector plate.

In a particular variant of this embodiment, the collar has a groove for receiving a seal interposed between said collar and the tube.

Preferably, the orifices are spaced apart by a pitch of between 5 mm and 10 mm, preferably between 6 mm and 8 mm.

In a particular embodiment, the collector plate is formed in a sheet of thickness between 0.7 mm and 2 mm, preferably between 1 mm and 1.5 mm.

The invention also relates to a manifold comprising a manifold plate as described above and a cover of plastic or metallic material, connected to the manifold plate by crimping, bonding, soldering or welding.

The invention also relates to a heat exchanger comprising such a manifold and tubes.

Preferably, the tubes are formed in a sheet of thickness between 0.1 mm and 0.5 mm, preferably between 0.2 mm and 0.3 mm.

Preferably, the tubes are obtained by electro-welding, bending in several channels or stapling.

• La figure 1 est une vue en perspective et en coupe transversale partielle d'une plaque collectrice et d'un tube selon un premier mode de réalisation de l'invention.
• La figure 2 est une vue analogue à celle de la figure 1 selon un deuxième mode de réalisation de l'invention.
• La figure 3 est une vue analogue à celle de la figure 1 selon un troisième mode de réalisation de l'invention.
• La figure 4 est une vue analogue à celle de la figure 1 selon un quatrième mode de réalisation de l'invention.

The invention will be better understood on reading the appended figures, which are provided by way of examples and have no limiting character.

• The figure 1 is a perspective view in partial cross-section of a manifold plate and a tube according to a first embodiment of the invention.
• The figure 2 is a view similar to that of the figure 1 according to a second embodiment of the invention.
• The figure 3 is a view similar to that of the figure 1 according to a third embodiment of the invention.
• The figure 4 is a view similar to that of the figure 1 according to a fourth embodiment of the invention.

We now refer to the figure 1 , on which we see the upper part of a tube 1 of oblong section. The tube 1 is presented here in a vertical orientation. The reference to its upper end is relative to the vertical direction V in the figure.

• grand axe TW = 34 mm (entre 10 et 100 mm)
• petit axe TT = 1,4 mm (entre 1 et 4 mm, préférentiellement entre 1 et 2 mm)

The oblong section of the tube has the following dimensions:

• major axis TW = 34 mm (between 10 and 100 mm)
• small axis TT = 1.4 mm (between 1 and 4 mm, preferably between 1 and 2 mm)

The tube is formed in a sheet 0.3 mm thick, by electro-welding, folding or stapling.

A collecting plate 3, designated plate below, is crossed by the tube 1.

Due to the partial section shown in the figure, we see only one section of this plate 3. This same section is repeated in the longitudinal direction L of the plate, as many times as the plate receives tubes, which are arranged in row parallel to each other, in this same longitudinal direction L. The spacing pitch between two neighboring tubes is between 5 and 10 mm, preferably between 6 and 8 mm.

We define the direction T which is perpendicular to the direction L, generally in the plane of extension of the plate. The direction T is that in which the long lengths of the ends of the tubes extend.

The plate 3 is formed in an aluminum sheet of thickness between 0.7 and 2 mm, preferably between 1 and 1.5 mm, by stamping.

The plate 3 has a wall 5 provided with orifices (only one of which is visible in the figure, as explained above), bordered by two longitudinal returns 9 which serve for the connection of the collector plate 5 with a cover (not shown). As is known, the cover closes the volume located above the collecting plate 5 to form a collecting box. The connection between the collector plate 5 and the cover is made by any suitable means, depending in particular on the material constituting the cover. For example, if the cover is made of plastic, the connection can be made by crimping or by gluing. Similarly, if the cover is made of metal, the connection can be made by crimping, gluing, soldering or welding. A seal (not shown) may, but is not compulsory, be interposed between the outer wall of the tube, a cover (not shown), the flange 9 and the collector plate.

Between the longitudinal returns 9 and the wall 5 provided with orifices, the collector plate is folded by forming two edges or spokes 11.

The wall 5 provided with orifices has, in cross section, a profile consisting of a central portion 13 and two lateral portions 15. The lateral portions 15 generally follow a curve 17 with a first radius of curvature R1. The central portion generally follows a curve 19 with a second radius of curvature R2, smaller than the first radius of curvature R1. The two portions, central 13 and lateral 15, form a bump towards the outside of the exchanger, therefore downwards in the figure.

The radii of curvature R1 and R2 can be defined by measuring the heights of the curves with respect to the plane defined by the two edges 11:
We designate H1 the height of the lateral portions 15 and H2 the height of the central portion 13. The radii R1 and R2 follow geometrically from these values H1, H2 and from the width 1 of the plate in the transverse direction.

$$\mathrm{0,05}<\mathrm{H}2/\mathrm{TW}<\mathrm{0,3}$$

Preferably, in order to optimize the reduction in stresses at the junction between the tube 1 and the plate 3 due to thermal expansions, the ratio between the heights H1, H2 and the major axis TW respects the following inequalities: $$0.05<\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">H</figure-callout>}1/\mathrm{TW}<0.2$$

$$0.05<\mathrm{H}2/\mathrm{TW}<0.3$$

$$\mathrm{H}2/\mathrm{TW}=\mathrm{0,12}$$

Here, given that H1 = 2 mm, H2 = 4 mm, TW = 34 mm, the inequalities are respected, because $$\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">H</figure-callout>}1/\mathrm{TW}=0.058$$

$$\mathrm{H}2/\mathrm{TW}=0.12$$

The orifice 7 has, in the vertical direction V of the drawing, which is a direction perpendicular to the longitudinal L and transverse directions T of the plate, an oblong projection of major axis TW, which is also designated more simply by width TW.

In addition, the orifice 7 comprises a collar 21 intended to cover part of the wall of the tube 1 passing through the wall 5 through this orifice 7, this collar 21 projecting towards the outside of the manifold. (so down in the figure). The collar 21 is obtained by stamping, during the forming of the plate 3. For this purpose, the material is pushed back by a punch during the stamping, as for the rest of the plate 3, which makes the operation easier. stamping. A disadvantage of this arrangement is that the tube 1 is less easy to insert into the orifice 7 during assembly of the manifold, because the end of the collar 21 through which the tube 1 must be inserted is a little narrower. On the other hand, this arrangement is advantageous in that it further reduces the stresses applied to the tube 1. It is therefore more favorable to the longevity of the exchanger.

The plate 3 may have a groove (not shown) for receiving a seal (not shown) interposed between a cover (not shown) and the plate 3.

The embodiment of the figure 2 differs from the previous one in that the collar 21 'projects from the wall towards the inside of the exchanger, that is to say upwards in the figure. Other information provided in relation to the figure 1 are valid for this figure 2 .

The embodiment of the figure 3 differs from the previous one in that the central portion 13 ′ of the profile forms a boss towards the inside of the exchanger, that is to say upwards in the figure. Other information provided in relation to Figures 1 and 2 are valid for this figure 3 .

The collar 21 'has the advantage that it facilitates the assembly of the exchanger because the tubes are easier to insert into the orifices than in the embodiment of the figure 1 .

This embodiment is also advantageous as regards the reduction of stresses exerted on the tube 1.

The embodiment of the figure 4 differs from the previous one in that the collector plate 3 'comprises a groove 23 in which a seal (not shown) can be inserted to ensure sealing with a cover (not shown).

The invention is not limited to the embodiments presented and other embodiments will be apparent to those skilled in the art.

Claims (9)

1. Header plate (3) for a heat exchanger, comprising a wall (5) provided with orifices (7), and through which tubes (1) arranged in rows in a longitudinal direction (L) are intended to pass, for which:

   - said wall (5) has, in cross section (T), a profile made up of a central portion (13, 13') and of two lateral portions (15),

   - the lateral portions (15) overall follow a first curve (17) with a first radius of curvature (R1),

   - the central portion (13, 13') overall follows a second curve (19) with a second radius of curvature (R2), smaller than the first radius of curvature (R1),

   the header plate (3) being bent to form two edges (11) between longitudinal turnups (9) and the wall (5),
   the header plate being characterized in that at least one of the orifices (7) comprises a collar (21) intended to cover part of the wall of the tube (1) passing through the wall (5) via this orifice, and in which at least one of the orifices (7) has, in a direction perpendicular to the longitudinal and transverse directions, an oblong projection of major axis TW, and in which, with respect to a plane passing through longitudinal edges (11) of the wall, the height of the lateral portions (15) is H1 and the height of the central portion (13) is H2, and in which the ratio between the heights H1, H2 and the major axis TW satisfies the following inequalities: $$0.05<\mathrm{H}1/\mathrm{TW}<0.2$$

   

   $$0.05<\mathrm{H}2/\mathrm{TW}<0.3.$$

   
2. Header plate according to the preceding claim, in which the major axis TW is comprised between 10 mm and 100 mm.
3. Header plate according to either one of the preceding claims, in which the collar (21) projects toward the outside of the header.
4. Header plate according to any one of the preceding claims, in which the orifices are spaced apart by a spacing comprised between 5 mm and 10 mm, preferably comprised between 6 mm and 8 mm.
5. Header plate according to any one of the preceding claims, formed in a metal sheet with a thickness comprised between 0.7 mm and 2 mm, preferably between 1 mm and 1.5 mm.
6. Header tank comprising a header plate (3) according to any one of the preceding claims and a cover made of plastic or of metal, connected to the header plate by crimping, bonding, brazing or welding.
7. Header tank according to the preceding claim, comprising a groove to accommodate a gasket interposed between the header plate and the cover.
8. Heat exchanger comprising a header tank according to either of Claims 6 and 7, and tubes formed in a metal sheet with a thickness comprised between 0.1 mm and 0.5 mm, preferably between 0.2 mm and 0.3 mm.
9. Heat exchanger comprising a header tank according to Claim 7 and tubes obtained by electric arc welding, bending into several canals, or clipping.

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