EP1321734A1 - Flat tubes heat exchanger and fabricating process associated - Google Patents

Abstract

Flat pipe heat exchanger comprises at least one collecting tube (211) and a number of flat pipe elements (209) connected to the collecting tube. Each flat pipe element has at least one torsion region. Two adjacently arranged flat pipe elements are joined together in a form-locking manner. <??>An Independent claim is also included for a process for manufacturing flat pipe elements for the above flat pipe heat exchanger. Preferred Features: Each flat pipe element has two torsion regions. Each torsion region is arranged adjacent to one of the collecting tubes.

Description

The invention relates to a flat tube heat exchanger, in particular for a heating or air conditioning system for a motor vehicle according to the preamble of claim 1, and a method for producing such Flat tube heat exchanger according to the preamble of Claim 22.

In the older German patent applications 100 49 256.8 and 101 05 201.2 are different flat tube heat exchangers, especially in Serpentine construction, described with flat tube connection structures, at which two serpentine flat tubes with flat side against each other Ends in a respective manifold open to a refrigerant parallel into the flat tubes in and out of the flat tubes out. Furthermore, there are examples of serpentine heat exchanger blocks shown, in which two adjacent multi-channel serpentine flat tubes with flat side abutting end portions in one Open the deflection pipe section. The serpentine flat tubes open at the other end in a cross-divided collection tube piece, one half as Distributor for feeding the refrigerant into a part of the channels each Flat tube and the other half acts as a collector, in the other Channels of each flat tube open. In the Umlenkrohrstücken is therefore the refrigerant in block depth direction from one to the other channels deflected the respective flat tube. For the preparation of these structures for Connection of two adjacent serpentine flat tubes to a manifold section or Umlenkrohrstück be the two serpentine flat tubes prefabricated as separate components, each with a straight Flachrohrendteil flat side together and with the abutting ends in the Collecting or deflecting tube piece inserted and sealed. Such flat tube heat exchanger allow, in particular with regard to production costs, still wishes open.

EP 0 414 433 discloses a duplex heat exchanger comprising a Refrigerant flow in cross-countercurrent allows by two of successively arranged flat heat exchangers, hereinafter referred to as Blocks designated, each with two headers, over a variety consists of flat tubes connected to each other. The two blocks are connected to each other by means of flange and O-ring seals, for which they are separated, clamped, soldered and soldered together after soldering need to be connected. Such a duplex heat exchanger Made of two blocks comes with a variety of items and one associated with relatively high production costs, making the production expensive is.

It is an object of the invention is a flat tube heat exchanger of the beginning to improve the type mentioned.

This object is achieved by a flat-tube heat exchanger with the Features of claim 1.

According to the invention, a flat tube heat exchanger, in particular for a heating or air conditioning system for a motor vehicle, with a plurality of flat tube elements and at least two with the flat tube elements connected collecting pipes provided, with two each Flat tube elements are connected to each other cohesively. This reduces the number of items and simplifies the assembly. It can a flat-tube heat exchanger according to the invention both as a gas cooler as well as being used as an evaporator

The flat tube elements preferably have two torsion regions. Such a design allows for easy production wherein the individual flat-tube elements are stable in themselves and thus process well to let. The dead space can be reduced by the fact that one each Torsionsbereich each flat tube element adjacent to each of the Collecting tubes is arranged.

Preferably, the flat tube elements are twisted by 90 °, in particular in the opposite direction, which offers manufacturing advantages. Alternatively, a torsion can be provided in the same direction, so that with two 90 ° turns a 180 ° rotation of the refrigerant over the entire width of the flat tube heat exchanger takes place.

According to a preferred embodiment, the flat tube elements so arranged between the headers and the manifolds interconnected, that they can be flowed through in countercurrent operation, wherein partition walls can be arranged in the headers, so that arranged within a block of between two headers Flat tube elements a subdivision is possible, and, for example, two blocks of manifold flat tube element assemblies arranged one behind the other are.

According to a preferred embodiment, the manifold is through formed into a groove shaped sheet metal strip whose edges in run substantially parallel to a longitudinal median plane of the channel and forming an open gap for receiving the free ends of the flat tubes serves. The edges can be a constant distance or a have repeated parallel offset (passes). This embodiment makes it possible in a simple way without any machining, Connecting flat tubes to each other through the manifold, the gap shaped edges being suitable for the soldering operation Form contact surfaces on the flat tube ends.

Preferably, in this case, the metal strip on its interior and / or Be outside lotplattiert, if he, what will be discussed, out a flat material is formed. This embodiment then offers the Possibility to simplify the soldering process.

In a further development, the edges of the metal strip may diverge outwards and so form an insertion bevel for the flat tubes, which the Assembly process much easier. The cross section of the gutter can in particular easy way to match an omega. It results in a stable Cross-section, which is also particularly easy for the insertion of the flat tube ends suitable. In this case, the closed area of the channel with cuts be provided for insertion of separation or end walls and also with openings that serve as inlet or outlet for the medium can serve.

According to a preferred embodiment, an end wall with provided a slot into which protrude one or more flat tubes.

It is also possible, however, to provide the separation or end walls to provide with recesses corresponding to the cross section of the channel, preferably So the Omega cross section, correspond and in the longitudinal direction let slide onto the gutters, so that the arrangement of incisions, optionally be provided later in the manifold must, is not necessary, and at the same time the space between Block ribs and feed pipes against misguided air. It will be later though also be shown that such cuts or openings also even before the transformation of the metal strip to its channel shape Punching can be introduced so that even then a cutting Editing is not required.

In development, the flat tubes with 90 ° twisted ends in the Spalt are used, with the twisted ends of several flat tubes in the interior of the gutter directly abut each other and so the distance set the individual flat tubes. At the same time but also the Distance of the twisted outer part of the flat tubes from the free end respectively be chosen so that the twisted part immediately as a stop to the can serve the gap-forming edges. Also towards the axis of Trough is possible in this way an alignment of the flat tubes, without that separate measures must be taken. Alternatively you can the twisted ends of the flat tubes spaced from each other. In In this case, there is not a continuous gap, but it is passages intended.

As previously indicated, it is particularly advantageous for the production the collection tube to provide a method in which as the starting material provided at least on one side solder plated flat sheet metal strip which is bent inwards to the gutter with the solder-plated side, whose edges are at least at one point away from each other, the one tailored to the strength of einzubeenden flat tubes Gap forms. Such a production also makes it possible in a simple way to provide punches in the initially flat sheet metal strip, which after forming such a metal strip to its final shape, such as in a multi-stage or progressive composite press tool can happen, the incisions for inserting the separation or End walls or the inflow and outflow openings for the medium form. Incidentally, the configuration can also be made such that after inserting the free flat tube ends in the gap between the Edge the later solder joint a certain distance from the flat tube end , so that is avoided by capillary forces in solder the flat tube channels runs. During manufacture, before soldering to Dichtlötung between the flat tubes also a solder foil or a thin lot-coated sheet metal are inserted.

In a manufacturing method according to the invention it is provided that a flat tube at the beginning of the flat tube, at a first point, which from Flat tube beginning at the length (L1) is spaced, at a second Position, which is spaced from the flat tube beginning by the length (L2), and at the flat tube end is rotated by 90 °, and the flat tube in his Center is provided with a Sollrisslinie and bent so that both Halves of the flat tube lie flat against each other in one end region come, wherein the wall of the flat tube at least partially, i. at the Outer radius, rips open.

In a further development of the invention, the two sheet halves at Circumference is straightened and compressed until touching lie together. The direct concern of the two End sections with their flat sides has a shape-stabilizing and space-saving effect In particular, this measure minimizes the width or height of the Slot on the terminal compartment component at least slightly more as the double thickness or height of the flat tube.

Since the two above the compressed and torn on the outside Arc in the Anschlußraumbeil opening flat tube parts Stay in one piece with each other on the inside of the arch is the Handling during assembly and assembly of this flat tube connection structure in comparison to the handling of two separate flat tube parts simplified. Another advantage of this manufacturing process is that the opening of the pipe bend at the outer radius without cutting takes place, so that no unwanted chips in the refrigerant circuit can reach or a removal of chips can be omitted. moreover This manufacturing process makes it very easy to set a stop limit for the insertion depth of the inserted into the terminal compartment part flat tube parts available by the widening transition from the compressed Arch to the two subsequent flat pipe sections as Stop can be used for the applied terminal compartment part, i.e. the length of the compressed bow area becomes smaller selected as the dimension of the terminal compartment component in the flat tube insertion direction.

In one embodiment of the invention is as a terminal compartment component Used manifold, a common, preferably on the entire collection tube length continuous longitudinal slot for insertion a plurality of juxtaposed pairs of adjacent flat tube part end portions has, what the building and assembling the flat tube connection structure and a whole, using this Heat exchanger flat tube block further facilitated. Alternatively, a Collecting tube to be used with passages. There is also a manifold with a common longitudinal slot for the Flachrohrstücke to be inserted therein easier to manufacture than a manifold, each with a slot for each flat tube part. In addition, when using a common and certainly not a continuous collection tube longitudinal slot so no exact manufacturing tolerances are met as in the case of individual Insertion slots for each two with flat side adjacent end portions einzusteckenden flat tube parts.

In a development of the invention, before carrying out the forming process Lot material inserted in the arc inner area, e.g. in shape a brazing sheet or a brazing foil. The solder material is during the forming process by squeezing the bow from the arch parts fixed and then stands in this area for Dichtlöten during a subsequent soldering available.

A development of the invention has the advantage that during the Process step for introducing the predetermined tear line simultaneously and thus without significant additional effort Lotflussstopprillen be introduced, with which stopped a flow of solder from the area of the joint or at least can be reduced.

Fig. 1

einen Teil eines zur Herstellung eines Sammelrohrs vorgesehenen flachen Blechstreifen,

Fig. 2

einen Abschnitt des aus dem Blechstreifen durch Umbiegen gebildeten Sammelrohres,

Fig. 3

das durch eingesetzte Trennwände in einen Zu- und in einen Abführabschnitt unterteilte Sammelrohr,

Fig. 4

eine perspektivische Darstellung eines Sammelrohrendes im noch nicht verschlossenen Zustand mit einem eingesetzten Sammelrohr,

Fig. 5

eine Darstellung ähnlich Fig. 4, jedoch mit einer eingesetzten Trennwand,

Fig. 6

eine Darstellung ähnlich Fig. 4, jedoch mit mehreren eingesetzten Flachrohren, deren Enden um 90° gegenüber den anderen Abschnitten verdreht sind,

Fig. 7

einen schematischen Längsschnitt durch einen Wärmeübertrager nach Fig. 6 mit eingesetzten Flachrohren,

Fig. 8

ein Sammelrohr ähnlich Fig. 4, jedoch mit einem Omegaquerschnitt zur Bildung einer Einführschräge,

Fig. 9

eine schematische Seitenansicht eines Teiles eines Wärmeübertragers, bei dem ein Sammelrohrquerschnitt nach Fig. 8 vorgesehen ist,

Fig. 10

die Ansicht eines der als Abschlusswand vorgesehenen Bleche der Fig. 9,

Fig. 11

eine Trennwand ähnlich Fig. 10, jedoch mit mehreren Aussparungen zur Nebeneinanderanordnung mehrerer Sammelrohre,

Fig. 12

ein Ausführungsbeispiel eines Wärmeübertragers mit mehreren nebeneinander liegenden Sammelrohren und einer Rohrausbildung in Serpentinenform,

Fig. 13

eine ausschnittweise Seitenansicht eines umgebogenen Flachrohrrohlings während des Einbringens einer Sollrisslinie am Bogenaußenradius,

Fig. 14

eine Draufsicht auf den Flachrohrbogen entlang des Pfeils II von Fig. 13,

Fig. 15

eine schematische Seitenansicht des Flachrohrrohlings nach Einbringen der Sollrisslinie und Verbringen in ein Umformwerkzeug,

Fig. 16

die Ansicht von Fig. 15 nach Durchführung des Umformvorgangs,

Fig. 17

eine Draufsicht auf den Flachrohrbogen entsprechend Fig. 14, jedoch nach beendetem Umformvorgang,

Fig. 18

eine Seitenansicht der durch Aufbringen eines Sammelrohrs auf den umgeformten Flachrohrbogen fertiggestellten Flachrohranschlussstruktur,

Fig. 19A-19D

einzelne Schritte zur Herstellung eines Flachrohres für einen erfindungsgemäßen Flachrohr-Wärmeübertrager,

Fig. 20

einen Flachrohr-Wärmeübertrager in Form eines Gaskühlers, und

Fig. 21

einen Gaskühler gemäß einer Variante des Ausführungsbeispiels.

The invention is illustrated by way of embodiments and variants thereof in the drawing and will be explained in the following. Show it:

Fig. 1

a part of a flat metal strip intended for the production of a collecting pipe,

Fig. 2

a portion of the collection tube formed by bending the sheet metal strip,

Fig. 3

the collecting tube, which is divided by an inserted dividing wall into an inlet and a discharge section,

Fig. 4

a perspective view of a header end in the not yet closed state with an inserted manifold,

Fig. 5

a representation similar to FIG. 4, but with an inserted partition,

Fig. 6

a representation similar to FIG. 4, but with several inserted flat tubes whose ends are rotated by 90 ° relative to the other sections,

Fig. 7

3 shows a schematic longitudinal section through a heat exchanger according to FIG. 6 with inserted flat tubes, FIG.

Fig. 8

a collection tube similar to FIG. 4, but with an omega cross section to form an insertion bevel,

Fig. 9

FIG. 2 a schematic side view of a part of a heat exchanger in which a manifold cross-section according to FIG. 8 is provided, FIG.

Fig. 10

the view of one of the provided as the end wall panels of FIG. 9,

Fig. 11

a partition wall similar to FIG. 10, but with a plurality of recesses for juxtaposing a plurality of manifolds,

Fig. 12

An embodiment of a heat exchanger with several adjacent headers and a pipe formation in serpentine form,

Fig. 13

a fragmentary side view of a bent flat tube blank during the introduction of a predetermined tear line at the arc outer radius,

Fig. 14

a plan view of the flat tube arc along the arrow II of Fig. 13,

Fig. 15

a schematic side view of the flat tube blank after introduction of the predetermined tear line and moving into a forming tool,

Fig. 16

the view of Fig. 15 after the forming process,

Fig. 17

a plan view of the flat tube arc according to FIG. 14, but after completion of the forming process,

Fig. 18

a side view of the finished by applying a collecting tube on the deformed flat tube arc flat tube connection structure,

Figs. 19A-19D

individual steps for producing a flat tube for a flat tube heat exchanger according to the invention,

Fig. 20

a flat tube heat exchanger in the form of a gas cooler, and

Fig. 21

a gas cooler according to a variant of the embodiment.

In Fig. 1 a piece of a flat sheet metal strip 1 'is shown, the Preparation of a manifold according to the present invention provided is. This sheet metal strip 1 'is a slot-shaped punching the second and provided with a round also punched-out opening 3. Of the Sheet metal strip 1 'is on the side facing away from the viewer in not Lotplattiert manner shown in detail.

It is bent in the direction of the arrows 4 and in the shape of FIG. 2 where it is transformed into a downwardly open channel 1. This Trough, for example, the cross-sectional shape of FIG. 4 obtained, and they has unilaterally projecting, mutually approximately parallel edges 5, the between them form a gap 6 (see also Fig. 3), which exploited to is to take the ends of a flat tube 7 - Fig. 4 -. These ends 7 'are only slightly above the narrowest point of the gap 6 upwards. If the channel 1 is used as a manifold, can in this way the passed through the manifold pipe involved in the heat transfer Medium in the open, in the interior of the channel 1 projecting flat tubes 7 enter. The ends 7 'of the flat tubes 7 are with the edges of the fifth soldered so that there is a tight receptacle for flat tubes, without a manifold by mechanical processing with insertion must be provided.

The ends or at least one end of a gutter may have at least one bevel in the direction of the flat tubes to be inserted, as the insertion aid to serve for the flat tubes.

FIGS. 3 and 5 make it clear that the channel 1 is relatively simple Way a manifold can be formed when partitions 8 different Divide sections of the channel against each other and, for example one of the openings 3 as an inflow opening to the manifold in the sense of Arrows 9 is flowed through and another opening 3 in another Section of the manifold as a drain opening to the outflow in the sense of Arrow 10 is used. The partitions 8 are in the slot openings 2 used, which are dimensioned so that the lowest point of Slot 2 in the final shape of the channel 2 of FIG. 3 or FIG. 5 with the Beginning of the end 7 'of the flat tube coincides. The partition 8, the for example, is formed as a solder-plated flat sheet, then can inserted into the slot 2 and then soldered in the channel 1, whereby the flat tubes 7 soldered to the edges 5 of the channel tight be so that a heat exchanger can be formed, the flat tubes flowed in a manner not shown by one of the media be involved in the heat transfer, while the second Medium through the manifold, i. through the channel 1 and through the flat tubes 7 flows. In this case, in the partition 8, an additional slot Be provided (not shown), in which the ends of the flat tubes 7 is inserted are. The partitions preferably have cutouts 21, which can at least partially take the pipes.

Fig. 6 shows a variant of a heat exchanger in so far as here Flat tubes 11 inserted into the groove formed as a collecting channel 1 are, whose inserted between the edges 5 ends 11 'in each case by 90 ° are twisted relative to the rest of the pipe section. How easy becomes clear, in such an embodiment, the flat tubes 11 be traversed in the direction of the arrow 12. Of course, there is also the Possibility to ribbed the spaces between the flat tubes 11 provided to improve heat transfer. For the rest can be the collecting duct formed by the channel 1 in the same way Divide partitions 8 in its length and with inlet or outlet openings 3, as explained with reference to FIGS. 1 to 5. The Production of the channel 1 also takes place in the same way.

FIG. 7 reveals in this context that the in the channel 1 pushed ends 11 'of the flat tubes 11 abut each other and so the distance between the individual flat tubes 11 in a simpler Way can be maintained.

FIG. 8 shows a variant of the collecting tube designed as a channel insofar as here the edges 5a diverge outwards and only in one Abut area of the flat tubes 7, which is slightly from the free end of the Randes is removed. The edges 5a in this way each form an insertion bevel for the free ends of the flat tubes 7. At the same time is twisted Pipe ends limits the engagement or insertion depth of the pipes, since by twisting the pipe ends, the width of the pipe ends with increasing distance from the pipe end grows. The soldering takes place in Contact area of the edges 5a with the flat tubes 7 instead.

Figs. 9 to 12 illustrate another way of attaching End walls for the trained as a gutter 1 collection tube. Here Be lotplattierte plates 13 with a recess 16 in the cross-sectional shape made the channel 1, which then after the flat tube 14 or several flat tubes are inserted into the channel, from the outside to the Trough 1 be deferred until it on the one or more flat tubes issue. In this position, the sheets 13 are then together with the Flat tube and the channel 1 soldered.

This embodiment also opens up the possibility of several such recesses 16 to arrange in a common plate 15, then, as Fig. 12 shows, as the end plate of three adjacent Hoppers in the form of grooves 1 is usable and for example the production of a serpentine heat exchanger with in loops laid flat tubes 17 and 18 allows.

Of course, other cross-sectional shapes for the channel 1 are conceivable. Decisive in each case is that the free edges of the channel form a gap whose width is matched to the strength of the flat tubes to be used. The embodiments shown in the drawing are particularly suitable for heat exchangers for a CO ₂ refrigeration cycle.

FIG. 12 also shows a cover strip 22 which serves as much as possible little false air is generated.

In Figs. 13 to 18 is an example of a method for producing a Flat tube connection structure illustrated in successive process steps, as in particular for heat exchangers of vehicle air conditioners is usable with carbon dioxide or another Refrigerants work.

Fig. 13 illustrates an initial process step in which a bent over Flat tube blank 101 provided with at least one sheet 102 becomes. This can be a serpentine flat tube blank with several bends or even just around a U-shaped flat tube blank with a single arc, in Fig. 13 for clarity half of the flat tube blank 101 only a bow and the two subsequent, rectilinear flat tube sections 101 a, 101 b explicitly are shown. As further indicated in FIG. 13, the outer radius of the Arc 102 centered over the entire flat tube width extending, transverse tear line introduced by means of a mandrel 103 or a needle. Fig. 14 shows in the plan view of the sheet 102 through the Scoring the outer edge generated tear line 104.

Fig. 15 illustrates the movement of the thus processed flat tube blank 101 in a forming tool, of which schematically only two here pressing jaws 105, 106 are shown. The flat tube blank 101 is inserted so far into the pressing tool that only his bow 102 with the outside crack line 104 between the Pressing jaws 105, 106 is located. The two adjoining the arch 102, rectilinear flat tube sections 101a, 101b are replaced by a interposed spacer block 107 supported and kept at a distance. In the area of the inside of the sheet a solder sheet 108 is inserted. Then the pressing tool is activated, i. the two pressing jaws 105, 106 move towards each other, as indicated by corresponding arrows.

This pressing process is terminated when the two halves 102a, 102b of the Arc 102 by the action of the pressing jaws 105, 106 straight bent are and lie with their flat sides against each other, where they introduced the Keep solder sheet 108 fixed between them. Fig. 16 illustrates this situation at the end of the pressing process.

By this forming process, the flat tube 101 tears at the outer radius of the arc while compressing the sheet 102 along the previously introduced tear line 104 on. As a result, everyone there Flow channel of the flat tube blank 101 to form a corresponding Mouth opening breaks open to the outside. In the top view of Fig. 17 on the deformed flat-tube arc area are to in this For example, eight flow channels belong to eight mouth openings 109 recognize.

When forming, it may cause a lateral pushing out of pipe material forming one bead each above and below the plane the tear line 104 on the two sides of the straight-curved flat tube halves 102a, 102b come. If this interferes, e.g. because several flat tubes close together in a continuous longitudinal slot of a manifold be inserted, this lateral bead formation can thereby be suppressed that lateral flanks on each of the two pressing jaws 105, 106 having a substantially the flat tube width corresponding Distance to be provided, which is a lateral evasion prevent tube material during the forming process. The flanks are standing essentially in front of the flat tube thickness, so that on the one hand the Do not hinder the forming process and on the other hand the same side Flanks of both pressing jaws 105, 106 in the end position shown in Fig. 16 of the pressing tool against each other and the side Prevent squeezing out of pipe material. In other words, will This realizes a calibration process, which together with the forming process takes place or adjoins this and with the Flachrohrendabschnitte 102a, 102b are calibrated in terms of width and height.

The part of the formed flat tube blank shown in FIGS. 16 and 17 thus includes two multi-channel flat tube parts 110, 111, respectively a rectilinear flat tube section 101a, 101b and the associated, bowed bow halves 102a, 102b include and over the not torn inner arc radius are integrally connected to each other. In this case, the two transition regions 112, 113 form between the respective End portion 102a, 102b and the respective center portion 101a, 101b a shoulder region whose outer dimension perpendicular to the flat tube plane from the double flat tube thickness in the end section area around the Height of the spacer block 107 increases in the central portion region, wherein the Height of the spacer block 107 the remaining distance of the Flachrohrmittelabschnitte 101a, 101b for later installation of the flat tube parts 110, 111 defined in a heat exchanger flat tube block and accordingly is selected.

After completion of the forming process, the pressing jaws 105, 106 are released, the deformed flat tube is removed, and the spacer block 107 will be removed. Then on the reshaped end section with the two rectilinear arc halves 102a, 102b a collecting manifold 114 deferred. Subsequently, the thus prefabricated flat pipe connection structure sealed by a conventional soldering, preferably in a common soldering process, in which the rest Soldered joints of a heat exchanger Flachrohrblockaufbaus made in which the connection structure is used.

The fixed between the straight bent sheet halves 102a, 102b solder sheet 108 is used for soldering during sealing soldering. Around a lot flow of avoiding or reducing the joint during the soldering process, Optionally corresponding soldering flux stop grooves 118 are provided, the preferred without much extra effort in the pipe bend area or the adjacent part of the rectilinear pipe center sections 101a, 101b can be introduced during the process step, in which by the scoring mandrel 103 and the scoring needle, the predetermined tear line 104th is introduced. In the example shown in Figs. 13 to 18, three are used Lötflussstopprillen 118 outside and inside by a corresponding Scratching tool 119, see Fig. 13, introduced into a pipe region which is in the finished tube block between the straight bent sheet halves 102a, 102b on the one hand and a corrugated fin on the other hand, each is inserted between the Flachrohrmittelabschnitte.

Preferably, the manifold 114 has an apparent from Fig. 18 Ω-shaped Cross section, i. the limiting the continuous longitudinal slot Longitudinal edges 115, 116 are slightly widened away from each other and thus facilitate the pushing on of the collecting tube 114 or the insertion the respective Flachrohrendabschnitts 102a, 102b. By that Collecting tube 114 with these slot-limiting longitudinal edges 115, 116th against the shoulder region 112, 113 of the formed flat tube for Plant comes, automatically the insertion depth of the two in one piece limited connected flat tube parts 110, 111 containing flat tube. Over an associated mouth opening are thus ever a flow channel each of the two multi-channel flat tube parts 110, 111 with a from Collector 114 defined collecting space 117 in fluid communication.

The flat-tube connection structure according to the invention according to FIG. 18 can be used, for example, for the aforementioned serpentine-type heat exchanger which is used as an evaporator in CO ₂ vehicle air conditioners and has a refrigerant deflection in the block depth direction, one or more of serpentine flat tubes being divided into a cross-divided collection tube piece and / or or open into an undivided Umlenkrohrstück. Both the connection to the transversely divided manifold and the connection to the or the Umlenkrohrstücke can be realized by the present, flat-tube connection structure according to the invention. For the cross-divided manifold pipe piece, the manifold 114 according to FIG. 18 can be used with the modification that it is provided with a corresponding transverse partition wall. For the Umlenkrohrstücke the undivided manifold 114 shown in FIG. 18 is used.

It is understood that except the embodiment explained above further, modified flat-tube connection structures can be produced according to the invention are. Thus, in some cases already one less extensive compression of the sheet halves are sufficient, the arc outside tearing of the flat tube and thus the opening of the or the flat tube channels leads, the arc halves then one more have a certain distance from each other. Next, it goes without saying that except the eight-channel flat tube shown any other conventional, bent Flat tube with only one flow channel or with any other number of flow channels can be used. Furthermore, understands itself, that according to need any number of according to the invention side by side pairs of flat tube sections formed by pipe bend forming in the common, preferably continuous Collector longitudinal slot can be inserted. Alternatively, several can Pairs of flat tube parts each in its own of several insertion slots be inserted, spaced from each other in a corresponding Collecting tube are introduced. Of course, instead of a manifold in appropriate applications, any other conventional Terminal compartment component can be used, e.g. a junction box.

In all cases, the inventive method has the advantage that couples of flat tube parts, with the flat side adjacent end portions in one Terminal compartment component are to be inserted, from a single flat tube blank can be made and in one piece with each other remain, with their flow channels without cutting in the bow area outside tearing open. The coherent flat tube parts, the parts of a rectilinear flat tube or a serpentine flat tube can represent when building a flat tube block for an associated heat exchanger comparatively easy to handle, and the insertion depth into the terminal compartment component can be automatically limit. By using the method according to the invention is thus the creation of a cost-effective and production-safe execution of the Refrigerant admission and exhaust of a heat exchanger, e.g. of the serpentine type and, if necessary, a low-cost version of a Refrigerant deflection in the tube block depth direction possible. The serpentine heat exchanger this can be done using a single continuous Flachrohrserpentine be built, but he can also consist of several serpentine segments, up to the case that the respective segment only from the two connected by a bow, straight sections of a U-shaped flat tube blank.

The production of a flat tube heat exchanger according to the invention takes place according to the embodiment described below, as in Figures 19A to 19D and Fig. 20 are shown schematically. Of a Coil is a flat tube blank 201 with a plurality of not in detail unwound lines and cut to length. Fig. 19A shows a corresponding cut to length flat tube blank 201, which at the flat tube beginning 202, at a first location 203, which from the flat tube beginning 202 is spaced by the length L1, at a second location 204, which from the Flat tube beginning 202 is spaced by the length L2, and at the flat tube end 205 is rotated by 90 °, the torsion in each of the same direction is done. Alternatively, as shown in FIGS. 19B to 19D, torsion may be provided in the opposite direction, wherein each twist is opposite to the one or more adjacent torsions.

As shown in Fig. 19B, the thus prepared flat tube blank 201 at its center 206 (i.e., spaced from the flat tube beginning 2 by the length (L1 + L2) / 2) provided with a predetermined breaking point or tear line 207 and order a mandrel D serving as a spacer is reshaped so that both Halves of the flat tube blank 201 come to rest at a distance A. Simultaneously with or subsequent to the provision of the predetermined tear line 207 also Lotflussstopprillen can be provided.

After reshaping the mandrel D in the direction of the tube rotations moved (see Fig. 19C), wherein after the displacement of the mandrel D in the space a solder material can be introduced, and a Baking tool B transforms the 180 ° arc portion 208 such that both Halves of the flat tube blank 201 come to lie flat against each other (see Fig. 19D). Here, the thorn D again ensures that the desired distance is maintained. In this forming process tears the Deck surface of the flat tube blank 201 on the predetermined tear line 207, so that the lines in the flat tube center 206 are fully opened. Thereafter, the mandrel D and the jaw tool B are removed. Hereinafter is referred to a flat tube half as a flat tube element 209 taken.

For the assembly of the individual flat tube blanks 201 and / or flat tube elements 209, for example, to a gas cooler, are at the flat tube beginning 202, at the flat tube end 205 and at the flat tube center 206, so on attached to both sides of the flat tube elements 209 headers (not ) Shown.

These headers have - according to a first variant - in their longitudinal direction extending slots, with one of the manifolds twice as has many slots, as the other manifold, since in each case a slot for the flat tube beginning 202 and the flat tube end 205 of slightly lower Width, but only one slot for the flat tube center 206, the doubled is required by slightly larger width.

According to an alternative variant, the headers are replaced by a Formed channel, for example, has a Ω-shaped cross section, as described above.

The headers have a certain number of refrigerant diversions on, which are tuned so that an optimal refrigerant flow causes becomes. The gas cooler block can - depending on the requirement - a common Corrugated rib or two separate corrugated fins, which is a far-reaching thermal Ensure decoupling.

Characterized in that after each passing through a width of the flat tube heat exchanger, i.e. after flowing through a flat tube element 209, the refrigerant enters a manifold, there is a mixing the refrigerant of the individual lines in the flat tube, so that at the beginning the further flow through another flat tube element 209 the Refrigerant in all lines has approximately the same temperature. Here, the torsion of the flat tubes also improves the mixing of the refrigerant.

From a plurality according to the above description formed flat tube blanks 201, ie flat tube elements 209, according to a variant a gas cooler 210 may be assembled as shown schematically in FIG is indicated. For this purpose, three flat tube elements 209, i. in the present Case a flat tube blank 201, which according to the above Description has been reshaped and a flat tube element 209, which was also converted according to the above description, however separated from its second half, Z-shaped joined together, wherein Collecting tubes 211 are provided at the deflection points 212 to a Allow mixing of the refrigerant. Thus, a 2-fold Deflection of the refrigerant in the depth of the gas cooler 210. The The flow direction of the refrigerant is indicated in FIG. 20 by arrows on the refrigerant inlet. and -austritt and the flow direction of the air to be cooled indicated by an arrow from below.

According to a variant shown in Fig. 21 in the form of a gas cooler are two individual blocks each with two manifolds 221, each individual block soldered for themselves and then on common side panels to a Block is assembled, provided. Here is a manifold 221 of each block is provided with a partition wall 223 so that the flat tube heat exchanger flows through a total of four sub-blocks. in this connection If the refrigerant enters the rear lower sub-block, it travels the flow through the sub-block via the manifold 221 in the rear upper part block, which flows through it, is then in the middle in the lower one Passed part of the front part block, flows through the sub-block and passes then in the upper front part block, where it after flowing through it exits again, as indicated by the arrows in Fig. 21.

In principle, entry into the rear upper part block is also possible. Of the Location of the refrigerant inlet is from the warm engine backflow certainly. Also, the use as an evaporator is possible.

Claims (31)

A flat tube heat exchanger having at least one collecting tube (211; 221) and a plurality of flat tube elements (7; 11; 101; 209) connected to the collecting tube (211; 221), each flat tube element (7; 11; 101 209) has at least one torsion region, characterized in that two adjacently arranged flat tube elements (7, 11, 101, 209) are connected to one another in a material-locking manner. Flat-tube heat exchanger according to claim 1, characterized in that each flat-tube element (11; 209) has two torsion regions, wherein a respective torsion region is arranged adjacent to one of the collecting tubes (211; 221). Flat tube heat exchanger according to one of the preceding claims, characterized in that the flat tube elements (11; 209) are twisted by 90 ° in each case. Flat tube heat exchanger according to claim 3, characterized in that the flat tube elements are twisted in the opposite direction. Flat-tube heat exchanger according to one of the preceding claims, characterized in that the partially twisted flat-tube elements (209) are arranged between the collecting tubes (211; 221) and connected to one another via the collecting tubes (211; 221) in such a way that they can be flowed through in countercurrent operation are. Flat-tube heat exchanger according to one of the preceding claims, characterized in that the collecting tube is formed by a metal strip (1 ') formed into a channel (1) whose edges (5; 5a) are substantially parallel to a longitudinal center plane of the channel (1). extend and form an open gap (6), which serves to receive the free ends of the flat tubes (7; 11). Heat exchanger according to claim 6, characterized in that the edges (5; 5a) of the channel (1) enclose an angle (α) between 0 and 90 degrees. Heat exchanger according to one of claims 6 and 7, characterized in that a chamfer is arranged on at least one of the edges (5) of the channel (1) at one end region. Heat exchanger according to one of claims 6 to 8, characterized in that the sheet-metal strip (1 ') is solder-plated on its inside and / or outside. Heat exchanger according to one of claims 6 to 9, characterized in that the edges (5a) of the trough (1) formed sheet metal strip (1 ') diverge outwardly and form an insertion bevel for the flat tubes (7; Heat exchanger according to one of claims 6 to 10, characterized in that the cross section of the channel (1) resembles or corresponds to an omega or is round or elliptical or oval, each with two protruding edges (5; 5a). Heat exchanger according to one of claims 6 to 11, characterized in that the closed region of the channel (1) with notches (2) for inserting separating and / or end walls (8 or 15) is provided. Heat exchanger according to claim 12, characterized in that the partition wall (8) has a slot. Heat exchanger according to one of claims 6 to 13, characterized in that an end wall (15) and / or partition wall (8) in a plurality of recesses (2) of grooves (1) engages. Heat exchanger according to one of claims 6 to 14, characterized in that an end wall (15) in a plurality of grooves (1) engages or closes. Heat exchanger according to one of claims 6 to 15, characterized in that an end wall (15) engages in a plurality of recesses (2) of grooves (1). Heat exchanger according to one of claims 6 to 16, characterized in that the closed region of the channel (1) is provided with openings (3) as an inlet or outlet opening for the medium. Heat exchanger according to one of claims 6 to 17, characterized in that end walls (15) are provided with recesses (16) which correspond to the cross section of the channel (1) and are pushed longitudinally onto the channel (1). Heat exchanger according to one of claims 6 to 18, characterized in that the flat tubes (11) with 90 ° twisted ends (11 ') are inserted into the gap (6). Heat exchanger according to one of claims 6 to 19, characterized in that the twisted ends (11 ') of a plurality of flat tubes (11) in the interior of the channel (1) abut each other. Heat exchanger according to one of claims 6 to 20, characterized in that the distance of the rotated main part of the flat tubes (11) from the free end of the pipe ends is in each case selected so that the twisted main portion serves as a stop on the gap (6). A process for the production of flat tube elements for a flat tube heat exchanger according to one of the preceding claims, characterized in that (a) a flat tube (11; 101; 201) at the flat tube beginning (202) at a first location (203) which is spaced from the flat tube beginning (202) by the length (L1) at a second location ( 204) which is spaced from the flat tube beginning (202) by the length (L2), and at the flat tube end (205) is rotated by 90 °, (b) the flat tube (11; 101; 201) is provided with a predetermined tear line (207) in its center (206) and bent so that both halves of the flat tube (11; 101; 201) lie flat against one another in an end region , wherein the wall of the flat tube (11, 101, 201) at least partially ruptures. A method according to claim 22, characterized in that for bending a mandrel (D) or spacer is used whose position is changed during the manufacturing process. A method according to claim 22 or 23, characterized in that the deformed flat tubes (11; 101; 201) are positioned on or in collecting tubes (211; 221) and are soldered in a fluid-tight manner. Method according to one of claims 22 to 24, characterized in that over the torn-open region of the flat tube a collecting tube (114) is pushed as a terminal compartment component. Method according to one of claims 22 to 25, characterized in that prior to performing the forming process, a solder material (108) inserted into the region arranged during bending or introduced before completion of the forming process. Method according to one of claims 22 to 26, characterized in that in the step of introducing the predetermined tear line one or more Lotflussstopprillen (18) are introduced. Method according to one of claims 22 to 27, characterized in that as a starting material for the collecting tube, a flat metal strip (1 ') soldered on at least one side is provided, which is bent with the solder-plated side inwards to the channel (1) whose Ranges (5; 5a) at least at one point have a distance from each other, which forms a matched to the strength of the flat tubes (7; 11) to be inserted gap (6). A method according to claim 28, characterized in that the distance of the edges (5; 5a) is less than the height of the flat tubes (7; 11), which are inserted into the channel (1), so that the tube ends with tension in the channel (1) are included. A method according to claim 29, characterized in that the distance is 0.1 mm to 1 mm less than the height of the flat tubes (7; 11). Method according to one of claims 28 to 30, characterized in that in the sheet metal strip (1) stampings are provided, which after bending the incisions (2) for inserting separation or end walls (8) or the inlet and outlet openings (3 ) for the medium.

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