Heat exchanger, in particular for a motor vehicle, tube for such an exchanger and method of manufacturing such a tube

Abstract

Heat exchanger, in particular for a motor vehicle, said exchanger being intended for heat exchange with a first fluid, said exchanger comprising a plurality of tubes (2) for circulation of said first fluid and a collector box (4), said tubes (2) having a longitudinal extension direction from a longitudinal end and opening through said end into said box (4) for passage of said first fluid between said tubes (2) and said box (4), said exchanger comprising stops (30) intended to limit insertion of said tubes (2) into said box (4) in said longitudinal extension direction. Figure for abstract: Figure 5

Description

Title of the invention: Heat exchanger, in particular for a motor vehicle, tube for such an exchanger and method of manufacturing such a tube

[0001] The invention relates to a heat exchanger as well as a tube for such an exchanger and a method of manufacturing such a tube. It is intended, in particular, for motor vehicles.

[0002] In this field, heat exchangers are known comprising a plurality of tubes for circulating a heat transfer liquid intended to exchange heat with a flow of air circulating between the tubes. The exchangers further comprise manifolds into which the tubes open through one of their longitudinal ends. To ensure good sealing, it is necessary for the tubes to be inserted sufficiently deeply into the manifolds.

[0003] However, the part of the tubes present inside the boxes causes pressure losses on the heat transfer fluid. If such pressure losses can possibly be sought in a portion of the tubes at the level of which the heat transfer fluid exchanges heat with the air flow, this to improve the heat exchange, it is not however of interest at the level of the collector boxes because these are parts of the heat exchanger which are not or only slightly involved in the heat exchange. They thus harm the overall efficiency of the heat exchange. In addition, a dispersion of performance of the exchangers has been observed due to differences in pressure losses from one exchanger to another.

[0004] The invention aims to at least partially overcome the above drawbacks and to this end proposes a heat exchanger, in particular for a motor vehicle, said exchanger being intended for heat exchange with a first fluid, said exchanger comprising a plurality of tubes for circulating said first fluid and a collector box, said tubes having a longitudinal extension direction from a longitudinal end and opening through said end into said box for passage of said first fluid between said tubes and said box, said exchanger comprising stops intended to limit insertion of said tubes into said box in said longitudinal extension direction.

[0005] Thanks to said stops, it is possible to control and limit the insertion of the tubes into the collector boxes. It is thus possible to fix the pressure losses due to the boxes within a desired limit and to optimize the overall efficiency of the exchanger while ensuring good sealing between the boxes and the tubes. In addition, this makes it possible to avoid producing exchangers with too great a dispersion of character- characteristics from one exchanger to another.

[0006] According to various additional characteristics of the invention, which may be taken together or separately and which form as many embodiments of the invention: - said box comprises a collector plate provided with passages for inserting the tubes, - said box comprises a cover located opposite the end holes of the tubes, - said collector plate and said cover are fixed to each other, - said box, in particular said collector plate and / or said cover, is in aluminum and / or aluminum alloy, - said tubes have one or more conduits for circulation of said first fluid, - said conduits open separately into said box, - said tubes are obtained by folding, - said tubes are obtained by extrusion, - said exchanger is configured to be a condenser of a refrigerant fluid, - said box, in particular said collector plate, is provided with collars at the level of the tube insertion passages, oriented towards the inside of the box, to form contact surfaces with the tubes.

[0007] According to a first aspect of the invention, said stops are located at the level of said tubes while projecting externally relative to said tubes.

[0008] According to various additional characteristics of this aspect of the invention, which may be taken together or separately and which form as many embodiments of the invention: - said stops rest on an external face of said box, - said stops bear against said collector plate, - said stops are presented in a point form or in the form of a cord making one turn of the corresponding tube, - said stops are made from the material of said tubes, - said stops are obtained by deformation of material of said tubes under the boss shape, - said tubes comprise deformations distributed longitudinally along said tubes and said stops are formed from at least one first of said deformations along said direction of extension of said tubes, - said stops are attached to said tubes, - there are one or two of said stops per conduit, - said stops are located at the level of a median axis of said conduit(s), - said stops have a circular profile, - said stops have a rectangular profile, - said stop(s) extend over a majority of the width of the corresponding conduit.

[0009] According to another aspect of the invention, said stops are formed from a fold of the box, said fold being oriented towards the inside of the box, said fold being configured to cooperate with the longitudinal end of said tubes.

[0010] According to various additional characteristics of this aspect of the invention, which may be taken together or separately and which form as many embodiments of the invention: - said fold comes from the material of said box, - said fold extends substantially along a height of said box, - said fold has a substantially rectilinear free edge, - said fold extends opposite a thickness of material of the tubes so as not to limit a passage section of said first fluid at the inlet and / or outlet of said tubes, - the collector plate comprises at least one fallen edge defining said fold, - said cover covers said collector plate at the level of faces of mutual fixation, - said fallen edge extends from one of said fixing faces of the collector plate, - said cover comprises at least one fallen edge defining said fold, - said collector plate has flared longitudinal edges forming a seat for said dropped edge(s).

[0011] The invention also relates to a tube for a heat exchanger as described above according to the first aspect of the invention. The said stop(s) provided on the tube are thus intended to bear on the external face of said box.

[0012] The invention also relates to a method of manufacturing such a tube, said method comprising a step of forming said stop(s).

[0013] According to a first embodiment, said method comprises a step of inserting an olive into the tube and a step of actuating a retractable lug outside said olive to form said stop(s).

[0014] According to a second embodiment, said method comprises a step of stamping said stop(s) in a sheet of material and a step of folding said sheet to form said tube.

[0015] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the detailed explanatory description which follows, of at least one embodiment of the invention given as purely illustrative and non-limiting example, with reference to the attached schematic drawings among which:

[0016] [Fig.l] illustrates schematically in perspective, in exploded form, an example of a heat exchanger according to the invention;

[0017] [Fig.2] schematically illustrates in perspective a longitudinal end of a tube according to the invention;

[0018] [Fig.3] schematically illustrates in perspective a longitudinal end of a tube according to the invention;

[0019] [Fig.4] schematically illustrates in perspective a longitudinal end of a tube, inserted into a collector plate, partially shown, according to a configuration in accordance with the invention;

[0020] [Fig.5] schematically illustrates in cross-sectional view a heat exchanger, partially shown, in accordance with the invention;

[0021] [Fig.6] shows [Fig.5] in a perspective view;

[0022] [Fig.7] schematically illustrates in cross-sectional view a heat exchanger, partially shown, in accordance with the invention;

[0023] [Fig.8] shows [Fig.7] in perspective view.

[0024] It should be noted that the terms “first”, “second”, “third”, etc. are only used to distinguish the components concerned from each other and do not indicate an order or a possible importance of said components.

[0025] As illustrated in [Fig.l], the invention relates to a heat exchanger, in particular for a motor vehicle. Said exchanger is intended to be positioned, for example, on the front of the vehicle, in particular behind a grille of said vehicle. It is configured to be fixed to a chassis of said vehicle, for example, either directly or via a cooling module.

[0026] Said exchanger is intended for a heat exchange with a first fluid. Said exchanger forms, for example, a condenser or a condenser / evaporator. Said first fluid is then, in particular, a refrigerant fluid intended to undergo a thermodynamic cycle along a circuit in which said exchanger is integrated. As a variant, said exchanger forms, for example, a cooling radiator. Said first fluid is then, in particular, a heat transfer fluid, for example a mixture of water and an antifreeze such as glycol.

[0027] Said exchanger comprises a plurality of tubes 2 for circulating said first fluid and one or more collector boxes 4, here two collector boxes 4. Said tubes 2 extend in a longitudinal extension direction between two opposite longitudinal ends and open respectively through said longitudinal ends into one of said boxes 4 for passage of said first fluid between said tubes 2 and said boxes 4. An inlet and an outlet of said first fluid in the exchanger are illustrated by arrows marked Fl.

[0028] Said exchanger is configured to be crossed by a second fluid, in particular an air flow, illustrated by an arrow marked F2, passing between the tubes 2. Said second fluid is thus intended to exchange heat with said first fluid thanks to the exchanger.

[0029] Preferably, said exchanger further comprises additional exchange surfaces 20, located between the tubes 2. They are configured to be crossed by the air flow F2. Said additional exchange surfaces 20 comprise, for example, fins and / or corrugated spacers.

[0030] Said boxes 4 comprise, for example, a collector plate 12, provided with passages 13 for inserting the tubes 2 and / or a cover 16, located opposite end orifices 6 of the tubes 2. Said collector plate 12 and said cover 16 are fixed to each other.

[0031] Here, said collector plate 12 and said cover 16 jointly form an element having a substantially tubular configuration. Said boxes 4, in particular said collector plates 12 and / or said covers 16, have, for example, a substantially rounded shape. The boxes 4 further comprise closing partitions 18, located at each of the opposite longitudinal ends of said tubular elements formed by the collector plates 12 and the covers 16.

[0032] In the illustrated embodiment, said tubes 2 are arranged parallel to each other, according to their direction of extension, being arranged in a vertical row. Said boxes 4 are oriented substantially perpendicular to the tubes 2.

[0033] Said exchanger further comprises cheeks or side plates 10 bordering the row of tubes 2, on either side.

[0034] Said box 4, in particular said collector plate 12 and / or said cover 16, said tubes 2, said additional surfaces 20 and / or said side plates 10 are, for example, made of aluminum and / or aluminum alloy. They are, in particular, brazed to each other, advantageously in a single operation.

[0035] Alternatively, said cover 16 is made of plastic material. It is fixed to the collector plate 12, in particular by crimping, for example by means of a cover foot compressing a seal 60 located here in a groove 62 formed in said collector plate 12.

[0036] In the illustrated embodiment, said exchanger comprises flanges 22 for passage of the first fluid, in communication with one and / or the other of the manifolds 4. Said exchanger also advantageously comprises mounting flanges 24, fixed to one and / or the other of the manifolds 4. Said passage and / or mounting flanges 22, 24 are, for example, made of aluminum and / or aluminum alloy. They are, in particular, brazed to the rest of the exchanger, advantageously in a single operation with the other components of the exchanger.

[0037] As is better seen in Figures 2 to 4, said tubes 2 have one or more conduits 32 for circulation of said first fluid. Said tubes 2 here have two large opposite faces 42, 42' connected by longitudinal edges 44, possibly rounded.

[0038] In Figures 2 to 4, said conduits 32 are two in number. Alternatively, the number of conduits is one, as illustrated in [Fig.8], or more than two, even if this is not illustrated.

[0039] In the case of tubes 2 provided with several circulation conduits 32, said conduits are separated, for example, by a separating partition 34. Advantageously, said conduits 32 open separately into said boxes 4. In other words, said partition 34 extends to the longitudinal end of the tubes.

[0040] Said tubes 2 are obtained, for example, by folding a strip of sheet metal. In Figures 2 to 4, said tubes are folded in B so that longitudinal edges of the sheet metal are located side by side along a median axis of the tube 2 and define said separating partition 34 by a double thickness of sheet metal. In [Fig.8], said longitudinal edges of the sheet metal are located along one of the longitudinal edges 36 of the tube 2. As a variant, not shown, said tubes 2 are obtained by extrusion.

[0041] As can be seen in Figures 4 and following, said box(es) 4, in particular said collector plate(s) 12, are advantageously provided with collars 38 at the level of the passages 13 for inserting the tubes 2. Said collars 38 are here oriented towards the inside of the boxes 4. They surround a longitudinal portion of the tubes 2, in the vicinity of their longitudinal ends, and make it possible to form contact surfaces, in particular by brazing, between said boxes 4 and said tubes 2.

[0042] Preferably, said end orifices 6 of the tubes 2 protrude from said collars 38 inside said boxes 4.

[0043] As illustrated in all of Figures 2 and following, according to the invention, said exchanger comprises stops 30 intended to limit an insertion of said tubes 2 into said box(es) 4 in said longitudinal extension direction of the tubes 2.

[0044] By controlling the insertion of the tubes 2 into the box(es) 4 using the stops 30, it is possible to ensure that the length of the tubes 2 inside the boxes 4 is sufficient to have good contact and therefore good sealing between the tubes 2 and the boxes 4, in particular at the level of any collars 38, while avoiding this length being too great, in order not to generate unnecessary pressure losses.

[0045] In the embodiments of figures 2 to 4, said stops 30 are located at the level of said tubes 2 while projecting outwardly relative to said tubes 2. Said stops 30 are, for example, supported on an external face 40 of said box 4, in particular of said collector plate 12.

[0046] In Figures 2 and 3, said stops 30 are presented, in particular, in a point form, for example circular as in [Fig.2] or elongated, for example substantially rectangular, as in [Fig.3]. In the latter case, it is noted that they are here oriented transversely, in particular perpendicularly, to the longitudinal direction of the tubes 2.

[0047] Said stops 30 are, for example, made from the material of said tubes 2. Preferably, said stops 30 are obtained by deformation of the material of said tubes 2 in the form of a boss, that is to say, in the form of a localized deformation of the tubes 2, said deformation creating a cavity inside the tubes 2, rather than being defined by an excess thickness of material of said tubes 2.

[0048] As a variant, not illustrated, said tubes 2 comprise deformations distributed longitudinally along the entire length of said tubes 2, for example to disturb the flow of the first and / or second fluid. Said stops 30 are then formed from at least one of the first and / or last of said deformations along said direction of extension of said tubes 2.

[0049] According to the embodiment of [Fig.2], a single said stop 30 is provided per conduit 32. In other words, according to the example shown where the tube is provided with two conduits 32, said tube 2 has two stops 30. These are circular stops. The said stop(s) 30 are located, for example, at the level of a median axis of said conduit(s) 32. As a variant, not illustrated, said stops are of elongated shape, centered or not on said median axis of said conduit(s).

[0050] According to the embodiment of [Fig. 3], said stops 30 are two per conduit. In other words, according to the example shown where the tube is provided with two conduits 32, said tube 2 has four stops 30. These are stops elongated in the rectilinear extension of one another.

[0051] The said stop(s) 30 possibly extend over a majority of a width of the corresponding conduit 32. This is the case, for example, in [Fig. 3] where the stops 30 corresponding to the same conduit 32, taken in combination, extend over the majority of the width of said conduit 32.

[0052] According to the embodiments mentioned above, it is observed that said stop(s) 30 are located on only one 42 of said large faces, the other 42' of said large faces not having any.

[0053] It should be noted that the invention also relates to a tube as presented above as well as a method of manufacturing such a tube.

[0054] Said method comprises a step of stamping the said stop(s) 50 of a sheet of material and a step of folding said sheet to form said tube 2.

[0055] As a variant, not illustrated, said method comprises a step of inserting an olive into the tube 2 and a step of actuating a retractable lug outside said olive. to form said stop(s) 50. Such an embodiment is particularly suitable, for example in the case of extruded tubes 2.

[0056] As illustrated in [Fig.4], said stops 30 are attached to said tubes 2. In the example shown, said stops 30 are in the form of a cord 46 making one turn of the corresponding tube 2. As a variant, the stops 30 are attached to said tubes 2 by having other shapes such as the circular and / or elongated shapes presented above.

[0057] According to other embodiments, illustrated in particular in Figures 5 to 8, said stops 30 are formed from a fold 48 towards the inside of the box. Said fold 48 is preferably configured to cooperate with the longitudinal end of said tubes. Said fold 48 is advantageously made from the material of said box(es) 4.

[0058] Said fold 48 extends substantially along a height of said box 4. Said fold 48 has a substantially rectilinear edge or free edge 50. In other words, said fold 48 is not interrupted along said box 4.

[0059] Preferably, said fold 48 extends opposite a thickness of material of the tubes 2 so as not to limit a passage section of said first fluid at the inlet and / or outlet of said tubes 2. In other words, said free edge 50 does not encroach on a passage section of the first fluid at the level of said outlet orifices 6. In other words, said fold 48 does not create pressure losses at the level of the passage of the first fluid between the tubes 2 and the boxes 4.

[0060] It may be noted that, between two passages 13 for inserting the neighboring tubes 2, in particular between two neighboring collars 38, said boxes 4 have a straight, internal section for circulation of the first fluid defined, for example, at least for 30% by said collector plate 12 and at least for 30% by said cover 16, in particular, for 60 to 70% by said collector plate 12 and for substantially 30 to 40% by said cover 16.

[0061] According to the embodiment of figures 5 and 6, said collector plate 12 comprises at least one fallen edge defining said fold 48.

[0062] Said cover 16 covers said collector plate 12 at the level of faces 51, 51', called lateral faces, of mutual fixing. Said fallen edges defining the folds 48 extend from said lateral faces 51 of the collector plate 12. A spacing of said lateral faces 51 of the collector plate 12 is here less than a maximum internal width of said collector plate 12. Said lateral faces 51' of the cover 16 cover said lateral faces 51 of the collector plate 12.

[0063] According to the embodiment of figures 7 and 8, said cover comprises at least one fallen edge defining said fold 48.

[0064] Said collector plate 12 here has flared longitudinal edges 54 forming a seat 56 for said fallen edge(s) defining the folds 48. In other words said collector plate 12 covers said cover 16 at a base of the fold 48 forming said fallen edge.

[0065] Said collector plate 12 and said cover 16 are advantageously of the same configuration for each of the collector boxes 4 located on either side of said tubes 2, only the flanges 22, 24 for fixing and / or passage of the first fluid being adapted, where appropriate.

Claims

Claims

1. Heat exchanger, in particular for a motor vehicle, said exchanger being intended for heat exchange with a first fluid, said exchanger comprising a plurality of tubes (2) for circulation of said first fluid and a collector box (4), said tubes (2) having a longitudinal extension direction from a longitudinal end and opening through said end into said box (4) for passage of said first fluid between said tubes (2) and said box (4), said exchanger comprising stops (30) intended to limit insertion of said tubes (2) into said box (4) in said longitudinal extension direction.

2. Exchanger according to the preceding claim in which said stops (30) are located at the level of said tubes (2) while projecting externally relative to said tubes (2), said stops (30) being supported on an external face (40) of said box (4).

3. Exchanger according to claim 1 wherein said stops (30) are formed from a fold (48) of the box (4), said fold (48) being oriented towards the inside of the box (4), said fold (48) being configured to cooperate with the longitudinal end of said tubes (2).

4. Exchanger according to the preceding claim in which said fold (48) extends substantially along a height of said box (4), said fold (48) having a substantially rectilinear free edge (50).

5. Exchanger according to any one of claims 3 or 4 wherein said fold (48) extends opposite a thickness of material of the tubes (2) so as not to limit a passage section of said first fluid at the inlet and / or outlet of said tubes (2).

6. Exchanger according to any one of claims 3 to 5 in which said box (4) comprises a collector plate (12), provided with passages (13) for inserting the tubes (2), and / or a cover (16) located opposite end orifices (6) of the tubes (2).

7. Exchanger according to the preceding claim in which the collector plate (12) comprises at least one fallen edge defining said fold (48).

8. Exchanger according to claim 6 wherein said cover (16) comprises at least one fallen edge defining said fold (48).

9. Tube for heat exchanger according to claim 2, the said stop(s) (30) provided on the tube being intended to bear on the face external (40) of said box (4).

10. A method of manufacturing a tube according to claim 9, said method comprising a step of forming said stop(s) (30).

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