JP7383687B2 - Collection box and corresponding heat exchanger - Google Patents

Description

The present invention relates to a recovery box for a heat exchanger, in particular for motor vehicles. The invention also relates to a corresponding heat exchanger. Such heat exchangers are used, for example, in motor vehicles, in particular as radiators for cooling systems, or in high-pressure applications, for example as condensers for air conditioning systems.

Generally, such heat exchangers include a core tube bundle and at least one collection box. The collection box is configured to receive the ends of the heat exchanger tubes.

For this purpose, the collection box is usually equipped with a header, for example in the form of a header plate. Typically, the collection box also includes a cover that secures the header plate and closes the collection box.

The header plate allows fluid to be distributed to a plurality of heat exchange tubes or allows fluid from the heat exchange tubes to be collected. The header plate usually consists of aluminum and can be manufactured by stamping, for example.

Header plates typically have a flat bottom.

However, in applications where pressure-bearing is intended, it is known to provide the header with an at least partially rounded bottom for pressure-bearing purposes. Additionally, header plates with flat or recessed bottoms typically have flanges surrounding an opening through which the ends of the tubes of the heat exchanger core pass.

For the introduction of tubes, openings such as slots are provided in the header plate by removing material or, on the other hand, without removing material. In the latter case, the material is forced by the tool into the volume defined by the collection box, thereby forming a flange around the opening for introducing the tube. Such flanges are called standard flanges.

The flange makes it possible to ensure contact between the tube and the opening in the header plate, as well as to obtain a high brazing quality when brazed, e.g. in all-aluminum exchangers. .

Generally, the tube is inserted into the aperture in the same direction as the tool used to form the flange around the aperture. To ensure accurate brazing and a highly robust and leak-tight assembly, the inserted tube typically extends partially into the collection box. In a particular solution, the tube projects up to approximately half the volume of the collection box into a volume that forms a reservoir for fluid.

However, by protruding the tube into the volume defined by the internal volume of the collection box and forming a reservoir for the fluid, a pressure loss is created in the fluid circuit. This internal pressure loss requires increased pumping capacity to maintain a particular flow rate of fluid.

According to known solutions, the collection box with a flat bottom can have a flange, referred to as an inverted flange. This means a flange made in the opposite direction to the insertion direction of the heat exchanger tube. Therefore, such a flange has a shape that widens away from the volume defined by the collection box. However, such inverted flanges are only slightly flared. In other words, this means that known inverted flanges define only a small inlet cone for the insertion of heat exchange tubes. The inlet cone may therefore not be sufficient to allow easy insertion of the heat exchange tube, and the solutions known from the prior art may present disadvantages regarding the insertion of the heat exchange tube into the header.

Since it is difficult to insert heat exchange tubes into headers with such reverse flanges, solutions such as the use of reverse flanges for headers with rounded bottoms have been replaced by conventional methods in which so-called standard flanges are preferred. It is never assumed in technology.

The aim of the invention is to provide a collection box capable of solving these problems of the prior art.

To this end, one subject of the invention is a collection box for a heat exchanger with a header having an at least partially rounded shape, said header comprising a plurality of heat exchangers of a heat exchanger. The header includes a plurality of openings for passing a tube through and a plurality of flanges surrounding the openings, and the header further includes a plurality of ridges, and the flanges are formed in the ridges of the header. and each have a substantially flared shape oriented away from the volume defined by the collection box.

According to a preferred embodiment, the flange is formed at the top of the ridge pointing away from the volume defined by the collection box.

Such an at least partially rounded bottom is suitable for pressure-bearing in high-pressure applications, and headers with such reverse flanges, i.e., facing in the direction opposite to the normal direction in which the tubes are inserted, are conventionally If so, the end of the tube that would have protruded into the volume defined by the collection box can be received.

Therefore, the end of the tube no longer opens into the volume defined by the collection box. This significantly reduces pressure losses associated with fluid flow through the heat exchanger tubes.

In short, by combining the at least partially rounded header and the plurality of ridges, there is sufficient material to form a fully flared inverted flange to facilitate the introduction of the heat exchanger tubes. It happens. In particular, the inverted flange according to the invention defines an inlet opening for the insertion of a substantially tulip-shaped heat exchange tube, which inlet opening is sufficiently wide due to the abundance of such material.

The collection box may further include one or more of the following features alone or in combination.
- the header has at least one wall, the shape of which is substantially concave towards the outside of the volume defined by the collection box;
- the ridge is formed on the wall;
- the ridges each have a maximum height of the order of 30% of the pitch of the tubes; - said flanges each have a substantially conical shape;
- The cone formed by the flange has an angle of the order of 30°, which facilitates the simultaneous introduction of several heat exchange tubes into the header opening surrounded by the flange.
- the flange has a first width and a second width, which is larger than the first width, for example about twice the first width, so that all the heat exchange A sufficiently wide opening is provided so that the tube can be easily introduced into the header opening.
- said first width is substantially equal to the width of a tube intended to be inserted into said opening;
- said flanges each have two convex substantially flared edges, said convex shape facing outward of the volume defined by said collection box;
- the flange has a height approximately half of the height of the ridge;
- the flanges are thinned relative to the ridges on the header, such that the ridges each have a first thickness and the flanges are thinned relative to the ridges on the header; each have a second thickness smaller than the thickness.
- The thinning of the material at the flange is at least 30%, or locally more than 50%, of the original thickness of the material. By thinning the material, the flange can be lengthened to provide sufficient flare to facilitate tube insertion.

The invention also relates to a heat exchanger, in particular for motor vehicles, with a bundle of heat exchange core tubes, the ends of said tubes being fixed in at least one collection box as mentioned above.

The heat exchanger may be a brazed heat exchanger.

As another option, the heat exchanger may be a heat exchanger in which the elements forming the collection box are mechanically assembled together.

According to one embodiment, the heat exchange tube has a height comprised between 0.8 mm and 2.5 mm, preferably between 1.2 mm and 1.8 mm.

The pitch of the heat exchange tubes, ie the distance between the centers of two heat exchange tubes, is comprised, for example, between 5 mm and 10 mm, preferably between 6 mm and 8 mm.

Further features and advantages of the invention will become more apparent from reading the following description, given by way of illustrative and non-limiting example, and from studying the accompanying drawings, in which: FIG.

1 is a perspective view of a collection box according to the invention for a heat exchanger; FIG. FIG. 2 is a partial cross-sectional view of the collection box of FIG. 1 receiving the end of one of the tubes of the heat exchanger core illustrated; FIG. 2 is a cross-sectional side view of the header of FIG. 1; FIG. 4 is a first perspective view of the header of the collection box of FIGS. 1 to 3; FIG. 4 is a second perspective view of the header of the collection box of FIGS. 1 to 3; Figure 4a and 4b is a cross-sectional view of the header of Figures 4a and 4b; FIG. 6 is an enlarged view of the header of FIG. 5 receiving the ends of the heat exchanger tubes;

Identical elements are provided with the same reference symbols in these drawings.

FIG. 1 shows in a schematic and simplified manner a fluid recovery box 1 for a heat exchanger (not shown), in particular in the automotive sector. The heat exchanger can be used as a radiator or as a condenser, especially for motor vehicles.

In particular, the invention may be applied to brazed heat exchangers.

The heat exchanger includes three bundles of core tubes. In FIG. 2 only one end of one tube 3 is shown. The tube 3 is made of aluminum or an aluminum alloy, for example. The tube 3 is, for example, a substantially flat tube 3.

The collection box 1 is configured to receive at least one end of the tube 3 of the heat exchanger. More specifically, it is configured to receive multiple ends of multiple tubes 3 of a heat exchanger (not shown). In FIG. 2 only one end of one tube 3 is shown.

For this purpose, the collection box 1 is equipped with a header 5. The collection box 1 also includes a cover 6 fixed to the header 5 to close the collection box 1.

The header 5 is made of, for example, aluminum or an aluminum alloy. The cover 6 may be constructed from aluminum or an aluminum alloy, or alternatively from plastic.

The cover 6 can be fixed to the header 5, for example by clipping, by brazing, or even by crimping.

Furthermore, the header 5 is provided with a plurality of openings 7 for passing the ends of the plurality of tubes 3.

The opening 7 has a substantially elongated shape, for example a slot.

The end of the tube 3 received in the opening 7 can be brazed to the header 5, for example.

According to one embodiment, the heat exchange tube 3 has a height comprised between 0.8 mm and 2.5 mm, preferably between 1.2 mm and 1.8 mm.

The pitch of the heat exchange tubes 3, ie the distance between the centers of two heat exchange tubes 3, is comprised, for example, between 5 mm and 10 mm, preferably between 6 mm and 8 mm.

According to the illustrated embodiment, the header 5 has a wall 8 forming a box end. Further, the collection box 1 includes a side wall 8' connected to the box end 8.

This box end 8 has an at least partially rounded shape.

According to the illustrated embodiment, the wall 8 forming the end of the box, also referred to as end wall 8, has a substantially concave shape towards the outside of the volume defined by the collection box 1. are doing. The end wall 8 of the header 5 is therefore of a substantially concave shape with respect to the internal volume defined by the collection box 1 and substantially concave with respect to the core of the tubes 3 of the heat exchanger. It has a convex shape. The convex portion faces outward from the volume defined by the collection box 1.

As shown in FIGS. 1 to 3, the collection box 1 further comprises a predetermined number of flanges 9 formed in the opening 7 in the header 5 for receiving the end of the tube 3. As shown in FIGS. More specifically, each opening 7 is surrounded by a flange 9. The flange 9 is produced in this example without removing material.

The header 5 further includes a plurality of deformable parts 11. The deformation 11 is made in the substantially recessed end wall 8 of the header 5 . For example, the deformed portion 11 is manufactured to form a regular pattern.

According to the illustrated embodiment, this pattern consists of ridges or corrugations 11.

The ridges 11 can be made symmetrically with respect to the longitudinal axis of the end wall 8 of the header 5. The ridges 11 thus have peaks extending alternately on one side and the other side of the longitudinal axis of the end wall 8 of the header 5. In other words, the ridged portion 11 includes, for example, a plurality of peaks facing inward of the volume defined by the collection box 1 and a plurality of opposing peaks oriented in a direction away from the volume defined by the collection box, i.e. It has a plurality of opposing tops facing towards the outside of the collection box 1 and towards the core made up of the plurality of tubes 3 of the heat exchanger.

A flange 9, better shown in FIGS. 4a and 4b, is formed in the ridge 11. More specifically, they are formed at the opposing tops of the ridged portions 11 facing away from the volume defined by the collection box. In particular, a plurality of openings 7 are formed by drilling or punching out the header 5 at the top of the ridge 11 pointing away from the volume defined by the collection box, and the flange 9 is formed by drilling or punching out the header 5 at the top of the ridge 11 pointing away from the volume defined by the collection box. It is made of surrounding materials.

In order to ensure that there is sufficient material in the ridge 11 to form the flange 9, the ridge 11 has a sufficient height h (see FIG. 5), for example a maximum of about 30% of the tube pitch. It is manufactured to have a height h.

The flange 9 thus formed faces away from the volume defined by the collection box 1, ie towards the core of the tubes 3 of the heat exchanger. For this reason, these flanges are referred to as reverse flanges 9.

Referring again to FIGS. 2 and 6, when the end of the tube 3 of the heat exchanger is inserted into the opening 7 surrounded by such an inverted flange 9, the end of the tube 3 is removed by the collection box 1. present in the region Z located between the top of the ridge 11 facing inward of the defined volume and the flat part of the box end 8 of the header 5, but protruding into the volume defined by the collection box 1; Not there. The absence of open tubes 3 within the volume of the collection box 1 improves performance in terms of fluid flow.

The flange 9 has a height h' that is sufficient to allow insertion of the end of the tube 3, for example, a height h' that is approximately half the height h of the ridged portion 11.

Furthermore, the flange 9 has a generally expanded shape, such as a tulip shape.

More specifically, the flanges 9 each have a substantially conical shape with an angle α (see FIG. 5) of, for example, about 30°.

The flange 9 thus has two flared edges 9a, 9b corresponding to two long edges joined to each other by two short edges 9c, 9d.

This flared or substantially conical shape facilitates the introduction into the header 5 of the end of the tube 3 from outside the volume defined by the collection box 1 towards the interior of the volume defined by the collection box 1. shall be taken as a thing.

The two flared edges 9a, 9b have, for example, a substantially convex shape, the convex shape pointing towards the outside of the volume defined by the collection box 1.

Referring to FIG. 5, the tulip-shaped flange 9 is
- a first width l ₁ at the top of the perforated or punched counter-ridge 11, which corresponds to the shortest width of the flange 9;
- an outer second width l ₂ corresponding to the maximum width of the flange 9;
They each have

The first width l ₁ is substantially the same as, or slightly larger than, the width of the tube 3 intended to be inserted into the opening 7 .

The maximum width l ₂ defines an opening 7 for the insertion of the end of the tube 3, surrounded by a flange 9. The second width l ₂ is made wide enough so that the ends of all tubes 3 of the heat exchanger (not shown) can be inserted into each opening 7 easily and especially simultaneously. For example, the second width _l2 is approximately twice the first width _l1 of the flange 9.

Furthermore, the flange 9 is made thinner than the ridged portion 11 provided on the header 5. Specifically, referring to FIG. 6, the ridge 11 has a first thickness e 1, for example, and the flange 9 has a second thickness e ₁ , which is smaller than the first thickness e ₁ of the ridge 11. It has a thickness _e2 .

The flange 9 can be simply thinned both at the long flared edges 9a, 9b and at the short connecting edges 9c, 9d.

For example, the thinning of the material is carried out at the flange 9, where the thinning may exceed 30% or locally 50% of the original thickness of the material.

By making the material thinner in the flange 9, the flange 9 can be made longer.

A header 5 with such an inverted flange 9 can therefore be used to connect the ends of a plurality of heat exchange tubes 3 of a heat exchanger without the need for special purpose tools to guide each tube 3 into the corresponding opening 7. It should be understood that this facilitates the simultaneous and easy introduction of

In particular, the reversed and flared flange 9 provides a sufficient opening for introduction into the interior of the volume defined by the collection box 1 from the outside of the collection box 1 .

Finally, these inverted flanges 9 allow the end of the tube 3 to be inserted into the volume defined by the collection box 1 without it opening, thereby preventing the fluid inside the collection box 1 from being removed. flow is promoted.

Claims (9)

A recovery box (1) for a heat exchanger comprising a header (5) having an at least partially rounded shape,
The header (5) is
- at least one wall (8);
- a plurality of ridges (11) formed on the wall (8);
- a plurality of openings ( 7) formed in said wall (8) for passage of a plurality of heat exchange tubes (3) of a heat exchanger;
- a plurality of flanges (9) surrounding said opening (7);
- two side walls (8') connected to said wall (8);
Equipped with
- the two side walls (8') each include a flat portion extending parallel to each other;
- the shape of said wall (8) is substantially concave towards the outside of the volume defined by said collection box (1);
- said ridges (11) have a plurality of peaks facing inward of the volume defined by said collection box (1) and a plurality of ridges oriented in a direction away from the volume defined by said collection box (1); having opposing tops of;
- said flanges (9) are formed on said opposite tops and each have a substantially flared shape oriented away from the volume defined by said collection box (1); collection box. The collection box according to claim 1 , wherein each of the ridged portions (11) has a height (h) of about 30% of the pitch of the tubes (3). Said flanges (9) each have two convex substantially flared edges (9a, 9b), said convex shape pointing towards the outside of the volume defined by said collection box (1). , The collection box according to claim 1 or 2 . The collection box according to claim 2 , wherein the flange (9) has a height (h') approximately half the height (h) of the ridged portion (11). The collection box according to any one of claims 1 to 4 , wherein the flange (9) is thinned relative to the ridged portion (11) on the header (5). Collection box according to claim 5 , wherein the thinning of the material at the flange (9) exceeds at least 30% of the original thickness of the material. A heat exchanger, in particular for automobiles, comprising a bundle of heat exchange core tubes (3), comprising:
an end of said tube (3) is fixed to at least one collection box (1);
The recovery box (1) is a heat exchanger according to any one of claims 1 to 6 . Heat exchanger according to claim 7 , wherein the heat exchange tube (3) has a height comprised between 0.8 mm and 2.5 mm. Heat exchanger according to claim 7 or 8 , wherein the pitch of the heat exchange tubes (3) is comprised between 5 mm and 10 mm.

Images