FR2789755A1 - Heat exchanger for car has metallic tape stamped to form indentations defining two semi-channels put together to create complete U-shaped channel - Google Patents

Abstract

Metallic tape (16) is stamped to form, successively on period (P), first indentation (18), second indentation (20) and separating section (22). Indentations are folded along line (24). Indentations define semi-channels (26, 28) that form complete U-shaped circulation channel when indentations are brought together.

Description

-4 Plate heat exchanger, brazed type, especially for

  motor vehicle The invention relates to heat exchangers, in

  especially for motor vehicles.

  It relates more particularly to a brazed heat exchanger comprising a multiplicity of plates each delimiting a fluid circulation channel, corrugated spacers arranged alternately between the plates, and at least one manifold communicating with the channels of

  circulation of the plates for the entry and exit of the fluid.

  Heat exchangers of this type are already known which are used in motor vehicles, in particular for

  form an evaporator forming part of an air conditioning circuit

  station. In this case, the exchanger is traversed by a fluid

refrigerant.

  The fluid circulates in each of the plates of the exchanger, and from one plate to another, exchanging heat with an air flow which circulates in the spaces delimited between the plates and occupied by the corrugated spacers, these

  the latter playing the role of fins.

  In known heat exchangers of this type, each of the

  plates, also called "blade", consists of two half

  plates produced by stamping a metal sheet and joined together by brazing at their periphery, to define a fluid circulation cavity. This cavity constitutes a channel which usually has a general U-shape, in the case of a heat exchanger with a single manifold at one end of the plates. In the case of a heat exchanger with two manifolds, one at each end of the plates, the plate has a generally elongated shape in I. These known heat exchangers therefore require a large number of parts which must be assembled, to know the half-plates joined in pairs to form the plates, the corrugated spacers arranged between the plates, as well as the manifold (s). As all these parts are metallic and assembled together by brazing, it is necessary to provide holding means for carrying out a pre-assembly of the latter.

  before brazing in a suitable oven.

  Indeed, if these parts are not correctly pre-assembled

  there is a risk that the soldering operation will not be carried out perfectly and that leaks will occur

  then on the heat exchanger, once put into service.

  The object of the invention is in particular to overcome the drawbacks

mentioned above.

  It aims in particular to provide a heat exchanger of the type defined in the introduction which has a greater number

  fewer parts than prior art heat exchangers

  and which can be manufactured by a simple and automatic process, without requiring any means of holding the parts

component of the heat exchanger.

  To this end, the invention provides a heat exchanger of the type defined in the introduction, in which the plates are formed from a deep-drawn and bent metal strip comprising pairs of imprints of complementary shapes arranged at spaced intervals, so that the imprints of the same pair are suitable for being reconciled

  one of the other by folding the ribbon to delimit conjoin-

a circulation channel.

  Thus, in its most general definition, all of the plates of the heat exchanger are formed from a single piece, namely a stamped and bent metal strip, which makes it possible to limit the number of pieces of the heat exchanger and also allows for pre-assembly in

easy conditions.

  In a first embodiment of the invention, the metal strip is designed to form only the plates of the exchanger. In this case, the spacers are made as separate parts and arranged between the plates, and likewise the or each manifold is also made in

  as a separate piece and assembled with the metallic tape.

  In this first embodiment, the metal strip advantageously comprises spacer sections which alternate with the pairs of imprints to define, after folding the

  ribbon, volumes used to each accommodate an interca-

wavy area.

  In another embodiment of the invention, the metal strip is designed to form both the plates and the spacers of the exchanger, while the or each manifold is produced as a separate piece and

  assembled on the metal tape.

  In this embodiment, the metal strip advantageously comprises corrugated sections which alternate with the pairs of imprints to form each, after folding the

ribbon, a corrugated interlayer.

  In either of the above two embodiments

  tees, it is advantageous that the channels delimited by the pairs of cavities each lead to at least one opening, and that the manifold communicates with the or

each opening.

  In an alternative embodiment, the or each collection box

  trice includes two stamped plates assembled, one of which

  form conical tips suitable for introduction respectively

  tively in the opening (s) of the channels.

  In another variant, the or each manifold

  includes separate tubes which respectively open

  in the channel openings.

  In a third embodiment of the invention, the metal strip is designed to form both the plates and the or each manifold of the exchanger, while the corrugated spacers are produced as parts

  separated and arranged between the plates.

  In this embodiment, the metal strip advantageously comprises shaped sections capable of constituting

  portions of manifold and grouped in pairs.

  Each half-plate can be extended by at least one portion of manifold, that is to say either a portion of manifold at one of its ends, or two portions of manifold, one at each end. The

  metal tape may further include spaced sections

  hearts which alternate with the pairs of imprints to define, after folding the ribbon, volumes used to

  each accommodate a corrugated interlayer.

  In a fourth embodiment of the invention, which constitutes an advanced version, the metal strip is designed to form both the plates, the corrugated spacers

  and the or each manifold of the exchanger.

  In this embodiment, the metal strip advantageously comprises corrugated sections which alternate with the pairs of imprints to form each, after folding the ribbon, a corrugated interlayer, as well as sections

  shaped to constitute portions of a collection box

  trice, these sections being in the extension of the footprints

half plates.

  In the two previous embodiments, the sections

  shaped to constitute portions of a collection box

  advantageously each have at least one opening.

  proper to come respectively in alignment with at least

  an opening of an adjacent shaped section.

  In the various embodiments mentioned above, the imprints of the same pair are connected by a fold line which can extend either in the direction of the width of the

  plates, either in the direction of the length of the plates.

  The heat exchanger of the invention can comprise either a single collecting box at one end of the plates, or two collecting plates, one at each end of the plates.

  In the following description, given by way of example, we

  refers to the accompanying drawings, in which: - Figure 1 is a partial side view of a heat exchanger

  heat according to a first embodiment of the invention

  tion; - Figure 2 is a partial view of a stamped metal strip, shown before folding, suitable for being part of a heat exchanger according to Figure 1; - Figure 3 is a side view corresponding to Figure 2; - Figure 4 is an exploded view similar to Figure 1; - Figure 5 is a partial side view of the manifold in an alternative embodiment; - Figure 6 is a partial side view of the manifold in another alternative embodiment; - Figure 7 is another partial side view of the manifold in another alternative embodiment; - Figure 8 is a partial view of a stamped ribbon, shown before folding, in an alternative embodiment; - Figure 9 is a partial view of a ribbon suitable for constituting a heat exchanger, according to another embodiment of the invention; - Figure 10 is a side view corresponding to Figure 9; - Figure 11 is a side view of a heat exchanger during assembly, obtained from a metal strip according to Figures 9 and 10; - Figure 12 is a partial view of a stamped ribbon, shown before folding, suitable for constituting a heat exchanger according to another embodiment of the invention;

  - Figure 13 is a view similar to Figure 12 corresponding

  dant a ribbon according to yet another embodiment of the invention; and - Figure 14 is a partial view of a stamped ribbon, shown before folding, suitable for constituting a heat exchanger

  heat to two manifolds.

  First of all, reference is made to FIG. 1 which shows a brazed heat exchanger, in particular for a motor vehicle, comprising a multiplicity of plates 10 spaced from one another and each delimiting a fluid circulation channel (not visible on the figure 1). Between the plates 10 are alternately arranged corrugated spacers 12 forming heat exchange fins. In addition,

  in the example shown, a manifold 14 communicates

  only with the plate circulation channels to allow the entry and exit of a fluid. Alternatively, the heat exchanger could include two manifolds, one

at each end of the plates.

  In the example considered, the heat exchanger constitutes an evaporator for a motor vehicle air conditioning circuit. Consequently, the exchanger is suitable for being traversed by a refrigerant which circulates in the plates and from one plate to another and exchanges heat with an air flow passing between the plates, to provide

  a flow of cooled air intended for air conditioning.

  According to the invention, the plates 10 are formed in one piece from a metal strip 16 (Figures 2 and

  3) which is stamped and then folded.

  As can be seen in Figures 2 and 3, the metal strip 16 is stamped to define each time a period P successively comprising (from top to bottom in the figures) a first cavity 18, a second cavity 20 and a spacer section 22. The impressions 18 and 20 are obtained by stamping the metal strip, which is advantageously made of aluminum or an aluminum-based alloy. The imprints 18 and 20 are adapted to be folded against each other by folding around a line 24 which extends transversely to the length of the ribbon. The imprints 18 and 20 respectively define half-channels 26 and 28 of complementary shapes which, after bringing the imprints 18 and 20 together, form

  together a complete channel, which in the example has sensi-

  definitely the shape of two successive U's.

  The half-channel 26 has two half-openings 30 and 32 arranged on the side opposite to the fold line 24 and, correspondingly, the half-channel 28 has two half-openings 34 and 36 located opposite the line. when the two indentations 18 and 20 are brought together, they are assembled one against the other along their periphery to be brazed, so that the half-openings 30 and 34, on the one hand, and the half-openings 32 and 36, on the other hand, define two openings for the inlet and the outlet of the fluid. The spacer sections 22 are each connected to an imprint 18 by a fold line 38 and to an imprint 20 by a fold line 40. All of the above fold lines are mutually parallel and transverse to the length of the ribbon. The distance between lines 24 and 38 is equal to the distance between lines 24 and 40. In addition, the distance between lines 38 and 40 corresponds substantially to the

width of the spacer section 22.

  To make the heat exchanger, the two cavities 18 and 20 of the same pair are folded against each other as shown by the arrow F1 in Figure 3 to form a plate, and each of the plates is then folded to come in parallel to an adjacent plate as shown by the

arrow F2.

  A one-piece assembly is thus produced, as shown in FIG. 4, which comprises only the plates 10, each formed from the assembly of an imprint 18 and an imprint 20, and the spacer sections 22. The spacers 12 are produced here as separate pieces and are then each introduced between two adjacent plates 10, as

  shown by arrows F3 in Figure 4.

  Similarly, the manifold 14 is produced here in the form of a separate part which is assembled on the aforementioned assembly. In the embodiment of FIG. 4, the manifold 14 comprises two stamped plates 42 and 44 assembled together around their periphery, the plate 42 forming conical end pieces 46 suitable for being introduced respectively into the openings of the channels, this is i.e. either in an opening resulting from the assembly of two half-openings 30 and 34 or in an opening resulting from the combination of two half-openings 30 and 34, or from the combination of two half-openings 32 and 36 as shown in the

  Figure 2. The tapered tips 46 are adapted to be intro

  duits in the aforementioned openings as represented by the

arrows F4.

  The aforementioned elements can be pre-assembled, then brazed in an appropriate oven, without requiring any particular holding means. To allow soldering, the various constituent parts of the heat exchanger are provided, on at least one of their faces, with a suitable solder plating. In the embodiment of Figure 5, the plate 44 of the manifold includes bosses 48 arranged

  respectively opposite the conical tips 46.

  In the embodiment of Figure 6, the holes 50 of the tips 46 have more or less large dimensions to allow to rebalance the flow rate of the fluid flowing between the channels. More particularly, it is made so that the hole 50-1 located closest to the injection orifice 52 has a smaller diameter than the hole 50-n disposed at

  the place furthest from the injection 52.

  In the alternative embodiment of Figure 7, the manifold 14 is formed by separate tubes 54 which end with bent ends 56 adapted to be introduced into the openings of the fluid circulation channels.

  In the alternative embodiment of FIG. 8, the footprints

  your 18 and 20 of the same pair, intended to make a plate, are connected to each other by a fold line 58 which extends in the direction of the length of the plate, instead of the direction of the width as shown in the Figure 2. As before, a spacer section 23 is introduced between the cavities of two adjacent plates to define a volume suitable for receiving a corrugated interlayer. However, in this configuration, the spacer section 23 is largely perforated (25) to allow the air flow to pass between the plates. Reference is now made to FIGS. 9 and 10 to describe another metallic strip 16 which is similar to that of FIG. 2 but which makes it possible to produce a more advanced heat exchanger, in the sense that this strip makes it possible to form both the plates 10, the corrugated inserts 12 and the

manifold plate 14.

  The metal strip 16 (Figures 9 and 10) includes

  indentations 18 and 20 arranged in pairs to form a joint

  tely a plate 10, and between which are arranged two shaped sections 60 and 62 adapted to constitute manifold portions. These sections 60 and 62 are grouped in pairs and are capable of being folded one against the other on either side of a fold line 64 to jointly form a manifold. The sections 60 and 62 are generally symmetrical and stamped to define a volume. Each of these sections has two openings 66 and 68 for the section 60 and 70 and 72 for the

section 62.

  Furthermore, between an imprint 18 of a pair of imprints and an imprint 20 of an adjacent pair of imprints is provided a corrugated interlayer which is here formed of two parts 74 and 76. The part 74 is of corrugated shape and can be folded relative to an imprint 20 along a fold line 78, while the portion 76 can be folded relative to an imprint 18 along a fold line

  80. In addition, the two parts 74 and 76 can be brought together.

  each other by folding around a line of

folding 82.

  The ribbon thus comprises periods P (FIG. 10) which successively include, and from top to bottom in the figures, an imprint 18, a shaped section 60, a shaped section 62, an imprint 20, an insert portion 74

and a part of insert 76.

  This tape can then be folded as shown in Figure 11 to form the heat exchanger. This embodiment is remarkable in that the whole of the heat exchanger is formed from a single piece,

  namely a metal ribbon stamped and folded on itself.

  It will be noted that, each time, an insert results from the assembly of two parts 74 and 76 folded against each other. It is also possible, within the framework of the invention, to

  realize other embodiments, which are intermediate

  diaries between that of Figures 1 to 8 and that of Figures 9 to 11. In the case of Figure 12, the metal strip 16 is designed to form both the plates and the corrugated inserts. Thus we find an arrangement similar to that of Figures 9 and 10, except that the shaped sections 60 and 62 of Figures 9 and 10 are here replaced by a spacer section 22 similar to that

shown in figure 2.

  In the embodiment of Figure 13, the metal strip 16 is designed to form both the plates and the manifold. We find a provision similar to that of Figures 9 and 10, except that the parts of tabs 74 and 76 are replaced by a section

  spacer 22 similar to that shown in FIGS. 2 and 3.

  In the embodiment of Figure 14, the heat exchanger comprises a manifold at each end of the plates. The plates and the manifold portions are formed on the same stamped ribbon, while the corrugated spacers are formed separately. The manifolds are formed by conforming sections

  arranged at the top and bottom of the footprints 18 and 20 of the half

  plates. The impressions 18 and 20 of the same pair are connected by a fold line 58, which extends in the direction of the length of the plates. Between the indentations 20 and 18 of two adjacent plates is located a spacer section 23, in

  large openwork part (25) to allow the passage of air.

  Two fold lines along the length of the plates

  are arranged on either side of the spacer sections.

  It will be understood that the invention is susceptible of numerous variants, provided that the plates of the heat exchanger are formed from the same metallic strip which

  is stamped and folded back on itself.

  In particular, the configuration of the circulation channels

  delimited between the plates can undergo many modifications

  cations and, in the simplest version, have a simple U shape in the case of a heat exchanger with a single manifold, or a simple elongated shape (I shape) in the case of a heat exchanger with two manifolds ..

  The invention finds a preferential application to exchanges.

  heat absorbers for motor vehicles, in particular for air conditioning evaporators. However, it could

  also be used to constitute a cooling radiator

  or a heating radiator, the fluid circulating in the exchanger then being a hot heat-transfer fluid, such as

  the coolant of the motor vehicle engine

the.

Claims (17)

Claims   1. Brazed heat exchanger comprising a multiplicity of plates (10) each delimiting a fluid circulation channel, corrugated spacers (12) arranged alternately between the plates (10), and at least one manifold communicating with the channels of circulation of the plates for the entry and exit of the fluid, characterized in that the plates (10) are formed from the same metallic strip (16) stamped and folded comprising pairs of indentations (18, 20) of complementary forms   arranged at spaced intervals so that the footprints   tes of the same pair are adapted to be brought closer to each other by folding (24) the metallic strip (16) to   jointly delimit a circulation channel.   2. Heat exchanger according to claim 1, character-   rised in that the metal strip (16) is designed to form only the plates (10) of the exchanger, in that the corrugated spacers (12) are produced as separate parts and arranged between the plates (10), and in that the or each manifold (14) is also made as   than a separate piece and assembled with the metal tape.   3. Heat exchanger according to claim 2, character-   rised in that the metal strip (16) comprises spacer sections (22) which alternate with the pairs of imprints (18, 20) to define, after folding the ribbon, volumes   serving to each accommodate a corrugated interlayer (12).   4. Heat exchanger according to claim 1, character-   risé in that the metal strip (16) is designed to form both the plates (10) and the corrugated spacers (12) of the exchanger, and in that the or each manifold (14) is made as that a separate and assembled room on the metal tape.   5. Heat exchanger according to claim 4, character-   risé in that the metal strip (16) comprises corrugated sections (74, 76) which alternate with the pairs of imprints (18, 20) to form each, after folding the ribbon, a corrugated interlayer (12).   6. Heat exchanger according to one of claims 1 to   , characterized in that the channels (26, 28) delimited by the pairs of cavities (18, 20) each lead to at least one opening (30, 34; 32, 36), and in that the or each manifold communicates with the or each opening.   7. Heat exchanger according to claim 6, character-   in that the or each collector plate comprises two assembled pressed plates (42, 44), one of which (42) forms   conical tips (46) suitable for being introduced respectively   in the channel openings.   8. Heat exchanger according to claim 6, character-   risé in that the or each collector plate comprises separate tubes (56) which respectively open into channel openings.   9. Heat exchanger according to claim 1, character-   risé in that the metal strip (16) is designed to form both the plates (10) and the or each manifold (14) of the exchanger, and in that the corrugated spacers (12) are made as that separate and arranged pieces between the plates (10).   10. Heat exchanger according to claim 9, character-   laughed in that the metal strip (16) comprises shaped sections (60, 62) capable of constituting portions of the manifold, in that each half-plate is extended by at least one portion of the manifold, and in that the   the metallic strip (16) further comprises spaced sections   hearts (22) which alternate with the pairs of imprints to define, after folding the ribbon, volumes used to   each accommodate a corrugated interlayer (12).   11. Heat exchanger according to claim 1, character-   risé in that the metal strip (16) is designed to form both the plates (10), the corrugated spacers (12) and   the or each collecting plate (14) of the exchanger.   12. Heat exchanger according to claim 11, character-   laughed in that the metal strip (16) comprises corrugated sections (74, 76) which alternate with the pairs of imprints (18, 20) to form each, after folding the ribbon, a corrugated interlayer (12), and in that the metal strip comprises shaped sections (60, 62) capable of constituting portions of the manifold, these sections being in the extension of the half-plates.   13. Heat exchanger according to one of claims 10   and 12, characterized in that the shaped sections (60, 62) capable of constituting manifold portions each have at least one opening (66, 68; 70, 72) adapted to come respectively in alignment with at least   an opening of an adjacent shaped section.   14. Heat exchanger according to one of claims 1 to   13, characterized in that the imprints (18, 20) of the same pair are connected by a fold line (24, 64) which   extends across the width of the plates.   15. Heat exchanger according to one of claims 1 to   13, characterized in that the imprints (18, 20) of the same pair are connected by a fold line (58) which extends   in the direction of the length of the plates.   16. Heat exchanger according to one of claims 1 to   , characterized in that it comprises a single collecting box   at one end of the plates.   17. Heat exchanger according to one of claims 1 to   , characterized in that it comprises two collection boxes   one at each end of the plates.