EP2300770B1 - Heat exchanger and method of production - Google Patents

Description

The invention relates to a heat exchanger with a collecting box made of plastic or metal, with metallic flat tube ends, which are part of a brazed heat exchanger network and with an adhesive bond, for the metallic flat tube ends in corresponding openings of the collecting tank, each with an annular space around the pipe ends, in which a silicone adhesive is located. Furthermore, the invention relates to a production method for the heat exchanger itself.

A heat exchanger with adhesive bond and a manufacturing process are from the previously unpublished German patent application with the file number DE 10 2008 021 544.9 known internally.

In the WO 2006 / 010435A1 Also, a silicone-based adhesive is used to make a heat exchanger for automobiles. It is an initially liquid mass, which is poured out there on the inside of a tube plate and then cured. An annular space around the pipe ends is not there. The pipe ends have been deformed, in particular widened, which causes manufacturing expense. Here, a large amount of the adhesive is needed, which also increases the cost of production.

In the WO 2007 / 009588A1 An automotive radiator is presented, which also has deformed tube ends and has no annular spaces. The pipe ends were not glued there but fixed by bending the pipe ends. This car radiator also has a separate metallic tubesheet, which is to be regarded as disadvantageous.

In the DE 38 09 944 C2 a cooler for internal combustion engines in motor vehicles is presented, which essentially corresponds to the preamble of claim 1. There are therefore annular spaces available. The adhesive is brought into the same by means of a metering device via channels leading to the annular spaces. The annuli are filled completely with the glue. The glue is relatively expensive and quite a lot of glue is needed. In this reference, it is proposed to use adhesives marketed under the trade name "Loctite". Although this relatively old proposal still seems progressive today, such coolers have not yet appeared on the market. One of the reasons for this may be that it has not been possible to make the adhesive bond durable.

The heat exchanger off FR 2 794 227 also has an adhesive connection. The adhesive comes into contact there with the medium flowing through the heat exchanger.

Out EP 159 729A For example, a curable plastic composition is known which contains silicone and has a very short cure time. The plastic composition is suitable for covering optical glass fibers.

Radiators for motor vehicles should at least guarantee a shelf life of about 10 years and be able to cope with all imaginable operating situations.

The applicant has extensively tested all possible adhesives and came to the conclusion that silicone adhesives promise the greatest success. Silicone adhesives are either of the so-called condensation-curing type (A) or of addition-curing type (B). The silicone adhesives of the condensation-curing type (A) excrete certain substances, for example acids or alcohols, when they cure, while those of the addition-crosslinking type (B) in the course of their curing lead to the formation of molecular chains without precipitating substances. The type B adhesives may comprise a catalyst, for example platinum or palladium. Such catalysts are usually in one of, for example, two components which must be mixed to prepare the ready-to-use adhesive. The catalysts cause, for example, a shortening of the curing time, and they can also help reduce the required temperature.

The object of the invention is to propose or make available a heat exchanger with a permanently adhesive bond and a manufacturing method for it.

This object is achieved by a heat exchanger having all the features of claim 1. The features of the manufacturing method are in claim 23.

It has been found that the fatigue strength of the adhesive bond is improved by virtue of the silicone adhesive being of the addition-crosslinking type, with a mounting plate being provided which delimits the annular spaces. The elastic modulus or storage modulus of the silicone adhesive is relatively low in order to minimize the forces of changes in length induced by temperature changes and the vibrations in the adhesive bond. It is approximately between 0.1 - 3.0 MPa.

The mounting plate is adhesively attached with its top on the collecting box. It can lie with its underside on the fins of the heat exchanger network.

Further improvements in effectiveness result from the fact that the annular spaces are filled to about 60-95% with the silicone adhesive, wherein the filled with the silicone adhesive height of the annular spaces about 5 - 15 mm and the width of the annular spaces about 0.5 - 3.0 mm ,

The filling of the annular spaces with the adhesive to about 60-95% of its volume, together with the specified preferred dimensions of the annular spaces, increases the elasticity of the adhesive bond, which is confirmed by numerous series of experiments carried out by the Applicant. A not inconsiderable number of coolers with adhesive bonds formed in this way will soon be tested in practice, that is, installed in motor vehicles in use on public roads. So far, all the coolers tested in the test laboratory and in the field of internal use have met expectations.

With regard to the dimensioning of the annular spaces, it has been found that this also depends on the length of the flat tubes provided in the individual case and on the dimensioning of the cross section of the flat tubes. For example, for flat tubes of intercoolers, which are about 10 mm thick (d, Figure 5 ), selecting the width and height of the annuli at the upper limits. For flat tubes of cooling liquid coolers, which are only about 1.0-1.5 mm thick (d), the width dimensions are more likely to be at the lower limit. For slightly longer flat tubes, for example, up to or over 1.0 m, as they are found in trucks, you would also rather provide a slightly wider and higher filled annulus, because then expected by temperature changes length changes of the flat tubes by means of the elasticity of the adhesive joints better to compensate. For example, an initially approximately rectangular cross-sectional area of the adhesive in the annular space under the mentioned thermal cycling loads in the direction of a parallelogram cross-sectional area - and back to the rectangular shape - move, which is ensured by the elastic properties of the selected adhesive together with the proposed design.

In previous brazed coolers it often comes to failure due to breaks in the solder joints tube / tube sheet, because the required elasticity is not present. It is expected that the invention will also lead to improvements in this respect. Preferably, a two-component silicone adhesive is used. But it can also be a silicone adhesive with a single component.

The tensile strength of the silicone adhesive used is about 3.0 to 7.0 MPa, preferably about 4.0 to 6.0 MPa.

The elongation of the silicone adhesive used is greater than 100%, for example, it is 150%.

It is advantageous if the silicone adhesive used has a catalyst from the group of platinum metals or their compounds.

The dynamic viscosity of the uncured silicone adhesive is about 20,000 - 60,000 cP. With these values, for example, the adhesive can be applied to the mounting plate like a worm without flowing apart.

The annular spaces can have approximately the same width over the filled with the silicone adhesive height.

However, it is also possible to make the annular spaces slightly conical, wherein they have over the filled with the silicone adhesive height a decreasing / increasing width dimension. The specified width dimensions refer to conical annular spaces on the median, that is, the specified width dimensions can be slightly exceeded in conical annular spaces.

The not filled with the silicone adhesive part of the annular spaces should be arranged pointing to the collection box.

The inventive method for producing a heat exchanger with an adhesive connection for metallic flat tube ends in corresponding openings of headers of the heat exchanger, in which a silicone adhesive is introduced into an annular space between the flat tube ends and the openings, is characterized in that the annular spaces with a memory module in Value range of 0.1 - 3.0 MPa possessing silicone adhesive of the addition-crosslinking type by means of a mounting plate filled and sealed. The mounting plate has openings corresponding to the flat tubes in order to be able to push the same onto the flat tube ends, so that, for example, it lies with the underside on cooling-air-side ribs. The opening edges of the mounting plate are close to the flat tube ends to avoid the escape of the adhesive as possible. The silicone adhesive is preferably applied to the top of the mounting plate and through the subsequent merger of mounting plate with the collecting box, whereby the flat tube ends are pushed into the openings of the collecting tank, pressed into the annular spaces.

The flat tube ends are pretreated as needed, at least cleaned with a suitable means to z. B. to remove solder flux, which have been found to be detrimental to a quality adhesive bond.

The flat tube ends are part of a heat exchanger network of flat tubes and cooling air-side ribs connected by means of CAB brazing processes, both of aluminum or of aluminum alloys. This method of soldering normally uses a non-corrosive flux, although intensive work is being done to completely eliminate flux. In any case, surface treatments may be required and performed on both the flat tube ends and the aperture walls.

The mounting plate has openings corresponding to the flat tubes in order to be able to push the same onto the flat tube ends, so that, for example, it lies with the underside on cooling-air-side ribs. According to a further development, the opening edges of the mounting plate are yieldingly close to the flat tube ends in order to be able to compensate for differences between the distances between the openings in the mounting plate and the spacings of the flat tube ends. Alternatively or additionally, the distances between the openings can be changed or adapted by means of an elastic or resilient design of the mounting plate. This also ensures that neither the flat tube ends nor the mounting plate are damaged and that no adhesive loss occurs due to too large gaps between the flat tube ends and the opening edges of the mounting plate.

Further features are content of the appended claims. Furthermore, features and their effects will become apparent from the following description of embodiments with reference to the accompanying drawings.

• Fig. 1 zeigt bevorzugte Abmessungen der Ringräume als Ergebnis durchgeführter Versuche;
• Fig. 2 zeigt eine perspektivische Teilansicht einer Montageplatte;
• Fig. 3 zeigt eine perspektivische Gesamtansicht einer Montageplatte;
• Fig. 4 zeigt einen Teillängsschnitt durch einen Sammelkasten des Wärmetauschers;
• Fig. 5 zeigt eine Ansicht auf ein Flachrohrende;
• Fig. 6 zeigt eine Ansicht auf einen Teil der Montageplatte mit Silikonkleber;
• Fig. 7 zeigt einen Querschnitt durch einen Sammelkasten;
• Fig. 8 zeigt eine perspektivische Teilansicht einer Montageplatte;
• Fig. 9 zeigt eine perspektivische und vergrößerte Teilansicht einer Montageplatte;
• Fig.10 zeigt perspektivisch eine Ausführungsform, wie die Öffnungsränder der Öffnungen der Montageplatte nachgiebig ausgebildet sind, in einer stark vergrößerten Ansicht;
• Fig. 11 zeigt den Querschnitt einer zweiten Ausführungsform;
• Fig.12 zeigt den Querschnitt einer dritten Ausführungsform;
• Fig. 13 zeigt den Querschnitt einer vierten Ausführungsform;
• Fig. 14 zeigt den Querschnitt einer ersten Ausführungsform zur nachgiebigen Gestaltung der Abstände der Öffnungen;
• Fig. 15 zeigt den Querschnitt einer zweiten Ausführungsform alternativ zur Fig. 14;
• Fig. 16 - 18 Herstellungsablauf und Frontansicht eines Wärmetauschers;
• Zahlreiche praktische Versuche und Simulationsrechnungen haben ergeben, dass die bevorzugte Breite b des Ringraums 6 bzw. der Klebeverbindung 1 zwischen 1, 5 - 2,5 mm liegt und die bevorzugte Höhe h des mit dem Silikonklebers SK befüllten Ringraumes 6 bzw. der Klebeverbindung 1 etwa zwischen 5, 0 - 10, 0 mm zu finden ist. Das soll durch die Fig. 1 verdeutlicht sein. Die Breite b und die Höhe h wurden in der Fig. 4 eingezeichnet.

The drawings show the following:

• Fig. 1 shows preferred dimensions of the annular spaces as a result of experiments carried out;
• Fig. 2 shows a partial perspective view of a mounting plate;
• Fig. 3 shows an overall perspective view of a mounting plate;
• Fig. 4 shows a partial longitudinal section through a header of the heat exchanger;
• Fig. 5 shows a view of a flat tube end;
• Fig. 6 shows a view of a part of the mounting plate with silicone adhesive;
• Fig. 7 shows a cross section through a collection box;
• Fig. 8 shows a partial perspective view of a mounting plate;
• Fig. 9 shows a perspective and enlarged partial view of a mounting plate;
• Figure 10 shows in perspective an embodiment, as the opening edges of the openings of the mounting plate are resiliently formed in a greatly enlarged view;
• Fig. 11 shows the cross section of a second embodiment;
• Figure 12 shows the cross section of a third embodiment;
• Fig. 13 shows the cross section of a fourth embodiment;
• Fig. 14 shows the cross section of a first embodiment for compliant configuration of the distances of the openings;
• Fig. 15 shows the cross section of a second embodiment as an alternative to Fig. 14 ;
• Fig. 16 - 18 Production process and front view of a heat exchanger;
• Numerous practical experiments and simulation calculations have shown that the preferred width b of the annular space 6 or the adhesive joint 1 is between 1.5 and 2.5 mm and the preferred height h of the annular space 6 filled with the silicone adhesive SK or of the adhesive joint 1 is approximately between 5, 0 - 10, 0 mm can be found. That should be through the Fig. 1 be clear. The width b and the height h were in the Fig. 4 located.

From the mentioned Fig. 4 also shows that the upper part 60 of the annular space 6 is not filled with the silicone adhesive SK . It has been found that the elasticity and the durability of the adhesive bond is to be further increased if the degree of filling of the annular spaces 6 with silicone adhesive SK is about 60-95% of the total volume of the annular spaces 6 .

The silicone adhesive SK used is of the addition-curing type, ie it does not precipitate any substances when it is cured. The storage modulus of the silicone adhesive SK in the exemplary embodiment is about 1.8 MPa, selected from a range between 0.5 and 3.0 MPa. This relatively low value contributes significantly to the durability of the adhesive bond, wherein the adhesive compound has excellent elastic properties and retains over a long period of time. In the preparation of the adhesive joint or the heat exchanger of the embodiment, the procedure was as follows:
Flat tubes 20 , as in Fig. 5 are alternately assembled with fins 30 to the heat exchanger network 3 . The heat exchanger network 3 becomes CAB soldering prepared accordingly, the soldering process is carried out. The free flat tube ends 2 are optionally freed of residues of the flux or other interfering residues or their surface is treated. A mounting plate 10 , a thin film of about 1.0 mm thickness or less, as in FIGS Fig. 2 and 3, is pushed with its openings 12 on the flat tube ends 2 , wherein the opening edges lie quite close to the flat tube walls. The mounting plate 10 can sit with its bottom finally on the ribs 30 without being attached thereto. In the Fig. 4 In contrast, a small distance between the bottom of the mounting plate 10 and the ribs 30 can be seen. Subsequently, a metered amount of silicone adhesive SK , as in Fig. 6 shown, serpentine on the inside of the mounting plate 10 applied. Thereafter, the collection box 5 is pushed with its openings 4 on the free flat tube ends. 2 In this case, the collecting box 5 comes together with the shell-like mounting plate 10 , that is, the wave-like edge 11 of the mounting plate 10 engages in a correspondingly shaped, circumferential groove 50 in the collecting box 5 a. The top of the mounting plate 10 glued to the bottom of the manifold 5 .

In the exemplary embodiment, the collecting box 5 is integrally formed. An embodiment not shown has a tube sheet of metal or plastic, in which the openings 4 are located, which is later connected to a box part along the peripheral edges to form the collecting box 5 .

By bringing together shell-like mounting plate 10 with collecting box 5 , especially the silicone adhesive SK is pressed into the annular spaces 6 . By the mentioned intervention of the edge 11 in the circumferential groove 50 prevents the merging of collection box 5 with mounting plate 5 of the silicone adhesive SK can escape laterally. He is rather forced to enter the annular spaces 6 . The height H of the edge 11 has therefore been designed so that it already engages in the groove 50 before the impressions of the silicone adhesive SK begins in the annular spaces 6 . The Indian Fig. 4 shown state is thus achieved. The degree of filling of the annular spaces 6 in this embodiment is about 75%, that is, 25% of the volume of the annular spaces 6 are not filled with the silicone adhesive SK . In the Fig. 4 these are the upper parts 6 of the annular spaces 60 . Like from the Fig. 4 It can also be seen that the very last ends of the flat tube ends 2 are in very narrow opening sections, the parts of the Openings 4 in the collecting box 5 are to avoid that the silicone adhesive SK comes later in substantial contact with the medium flowing through the heat exchanger.

For presentation in Fig. 4 It should be noted that the flat tube ends 2 practically do not protrude into the interior of the collecting tank 5 , even if the Fig. 4 could give a different impression. Namely, in its opening or bottom area, the collecting box 5 has a roughly semicircular contour, viewed in cross-section, in order to improve its pressure stability Fig. 4 could appear as if the flat tube ends 2 were clearly inwardly over, which is true only for the lying on the central longitudinal line lot of flat tube ends 2 . The internal pressure loss has therefore been reduced. The total cross section of the collecting tank 5 is round to oval, which is the Fig. 7 should show. The mounting plate 10 , one of the flat tubes 20 and a part of an annular space 6 were indicated there only in stylizing manner.

The tensile strength of the silicone adhesive SK in the embodiment is about 5.3 MPa selected from an advantageous range of 3.0 to 7.0 MPa.

The viscosity of the silicone adhesive SK is about 35,000 cP, selected from a range between 20,000 and 60,000 cP. With this value, the silicone adhesive SK can be applied without flowing apart.

Following the described assembly, a curing process is carried out, which is carried out in a drying oven, not shown, or on a drying line. The heat exchangers are maintained at a temperature of about 120 ° C for about 30 minutes, selected from a temperature range of 80-180 ° C and a time between 1-60 minutes. The silicone adhesive SK was mixed with a catalyst from the group of platinum metals in order to shorten the curing time.

Because the thickness of the wall parts a , b ( Fig. 5 ) of the flat tubes 20 is extremely low, namely in a range of 0.03 mm - 0.15 mm, because the ribs 30 are only about 0.03 mm - 0.09 mm thick and because, moreover, preferably no metallic tube sheet used A much lighter heat exchanger will be provided. Its performance characteristics are also significantly higher than for ordinary heat exchangers, partly because of the inner inserts c in the flat tubes 20 . Moreover, such heat exchangers require considerably less energy, for example for the soldering process. In the provision Such a heat exchanger makes the proposed invention a significant contribution.

Numerous manufacturing experiments have shown that, due to various manufacturing influences, the exact match of the distances between the flat tube ends with the spacing of the opening edges in the mounting plate is not guaranteed. This can lead to damage of the flat tube ends and the mounting plate, whereby the heat exchanger network and the mounting plate can be unusable. By examining various embodiments of the opening edges and the areas between the openings, it has been found that a compliant design of the opening edges and / or spacing of the openings precludes both the risk of damage from mismatching distances and the risk of adhesive loss due to excessive gaps. The compliance of the opening edges and / or the distances of the openings of the mounting plate can be represented for example by a locally lower material thickness of the mounting plate, supported by cuts in the opening edges.

In the production of the adhesive joint or the heat exchanger of the embodiment, the procedure is as follows:

Flat tubes 20 are alternately assembled with ribs 30 to the heat exchanger network 3 . The heat exchanger network 3 is prepared according to the CAB-soldering, the soldering process is carried out. The free flat tube ends 2 are optionally freed of residues of the flux or other interfering residues or their surface is treated. A mounting plate 10 , a thin film of about 1.0 mm thickness or less is pushed with its openings 12 on the flat tube ends 2 , wherein the resilient opening edges 13 create on the narrow and broad sides of the flat tubes 20 .

The opening edges 13 may be formed with cuts 14 and / or tapering 15 , as in the Fig. 8 - 10 is shown. A second embodiment of the opening edges 13 is in Fig. 12 shown, wherein the compliance is represented by a locally reduced material thickness in the form of a paragraph 16 . As a third embodiment, the locally reduced material thickness is realized by means of grooves 17 or beads, as in Fig. 13 is shown, wherein the shape of the grooves or beads need not be limited to a circular arc-shaped depression in cross-section. Further embodiments show in the Fig. 14 and 15 the resilient configuration of the distances of the openings 12 in the mounting plate 10 by reducing the material thickness in the edge regions between the openings 12 and the wave-like edges 11 of the mounting plate 10 , ( Fig. 14 ), or between the openings 12 across the mounting plate 10 , (FIG. Fig. 15 ).

Any but appropriate combinations of the embodiments described above are possible in order to achieve the flexibility, or to increase the same further.

The mounting plate 10 can sit with its bottom finally on the ribs 30 without being attached thereto. In the Fig. 4 In contrast, a small distance between the bottom of the mounting plate 10 and the ribs 30 can be seen. Subsequently, a metered amount of the silicone adhesive SK , a serpentine on the inside of the mounting plate 10 is applied (not shown). Thereafter, the collection box 5 is pushed with its holes 4 on the free flat tube ends. 2 In this case, the collecting box 5 comes together with the shell-like mounting plate 10 , that is, the wave-like edge 11 of the mounting plate 10 engages in a correspondingly shaped, circumferential groove 50 in the collecting box 5 a. The top of the mounting plate 10 glued to the bottom of the manifold 5 .

By merging the shell-like mounting plate 10 with the collecting box 5 , the silicone adhesive SK is pressed into the annular spaces 6 . By the mentioned intervention of the edge 11 in the circumferential groove 50 prevents the merging of the collecting box 5 with the mounting plate 10 of the silicone adhesive SK can escape laterally. He is rather forced to enter the annular spaces 6 .

In the Fig. 18 a cooling liquid cooler (heat exchanger) of a truck is shown, the heat exchanger network is traversed by cooling air. This Kühlflüssigkeitkühler has the proposed adhesive bond to the flat tube ends 2 and was prepared according to the described method. The FIGS. 16 and 17 show the production process of the Kühlflüssigkeitskühlers, starting from an already brazed heat exchanger network 3 , consisting of flat tubes 20 and not shown there ribs 30th First, the mounting plate 10 is pushed onto the flat tube ends. The silicon adhesive SK of the addition-curing type is applied and the flat tube ends 2 are inserted into the Openings of the collecting tank 5 is pushed, wherein the mounting plate 10 is brought together with the collecting box 5 and the silicone adhesive is pressed into the annular spaces.

Claims (30)

1. Heat exchanger having a collecting tank (5) made of plastic or metal, having flat metal tube ends (2) that are part of a brazed heat exchanger network (3) and having an adhesive connection (1) for the flat metal tube ends (2) in corresponding openings (4) in the collecting tank (5), each opening having an annular space (6) around the flat tube ends (2), in which a silicone adhesive (SK) is located, the extreme ends of the flat tube ends (2) being inserted in very narrow opening portions that are part of the openings in the collecting tank, in order to avoid the silicone adhesive later coming into significant contact with the medium flowing through the heat exchanger,
   the silicone adhesive (SK) being of the addition-crosslinking type and having a storage modulus in the range of values between 0.1 and 3.0 MPa,
   a mounting plate (10) being formed and arranged as a thin foil, which closes the annular spaces (8).
2. Heat exchanger according to Claim 1, characterized in that the annular spaces (6) are filled to approximately 60 to 95% of their volume with the silicone adhesive (SK).
3. Heat exchanger according to Claim 1, characterized in that the height (h) of the annular spaces (6) that is filled with the silicone adhesive (SK) is approximately 5 to 15 mm and the width (b) of the annular spaces (6) is approximately 0.5 to 3.0 mm.
4. Heat exchanger according to Claim 1, characterized in that the silicone adhesive (SK) consists of one component or of at least two components.
5. Heat exchanger according to Claim 1, characterized in that the elongation of the silicone adhesive is greater than 100%, for example 150%.
6. Heat exchanger according to claim 1, characterized in that the tensile strength of the silicone adhesive (SK) lies approximately between 3.0 and 7.0 MPa, preferably at approximately 4.0 to 6.0 MPa.
7. Heat exchanger according to Claim 1, characterized in that the silicone adhesive (SK) has a catalyst from the group of platinum metals or their compounds.
8. Heat exchanger according to Claim 1, characterized in that the dynamic viscosity of the non-cured silicone adhesive (SK) is approximately 20,000 to 60,000 cP.
9. Heat exchanger according to Claim 1, characterized in that the annular spaces (6) have approximately the same width (b) over the height (h) that is filled with the silicone adhesive (SK).
10. Heat exchanger according to one of Claims 1 to 8, characterized in that the annular spaces (6) have a decreasing/increasing width (b) over the height (h) that is filled with the silicone adhesive (SK).
11. Heat exchanger according to Claims 1 and 2, characterized in that the part (60) of the annular spaces (6) that is not filled with the silicone adhesive (SK) is arranged facing the collecting tank (5).
12. Heat exchanger according to Claim 1, characterized in that the mounting plate (10) is formed with an upright, peripheral edge (11) of the height (H).
13. Heat exchanger according to Claims 1 and 12, characterized in that the edge (11) of the mounting plate (10) engages in a corresponding groove (50) of the collecting tank (5) and in that the mounting plate (10) either lies with its underside on ribs (30) of the brazed heat exchanger network (3) or is arranged at a small distance from the ribs (30).
14. Heat exchanger according to Claim 1, characterized in that the collecting tank (5) is of an approximately round to oval form in cross section, in order to improve its compressive stability.
15. Heat exchanger according to Claim 1, characterized in that the mounting plate (10) has openings (12), the edges (13) of which and/or the distances between the openings (12) are formed in a yielding manner.
16. Heat exchanger according to Claim 15, characterized in that the yielding compliance of the edges (13) of the openings is represented by a local reduction in the material thickness of the mounting plate (10).
17. Heat exchanger according to Claims 15 and 16, characterized in that the yielding compliance of the edges of the openings is represented by cuts (14) in the edges (13) of the openings.
18. Heat exchanger according to Claim 16, characterized in that the local reduction in the material thickness of the mounting plate is represented by a cross section (15) tapering to a point.
19. Heat exchanger according to Claim 16, characterized in that the local reduction in the material thickness of the mounting plate (10) is represented by a cross section with an offset (16).
20. Heat exchanger according to Claim 16, characterized in that the local reduction in the material thickness of the mounting plate (10) is represented by a cross section with two or more channels (17).
21. Heat exchanger according to Claim 15, characterized in that the yielding compliance of the distances between the openings (12) is represented by a reduction in the material thickness between the openings (12) in the mounting plate (10).
22. Heat exchanger according to Claim 15, characterized in that the yielding compliance of the distances between the openings (12) is represented by a reduction in the material thickness in the regions between the openings (12) in the mounting plate (10) and the wave-like edges (11) of the mounting plate (10).
23. Method for producing a heat exchanger according to one of Claims 1 - 22, having an adhesive connection (1) for flat metal tube ends (2) in corresponding openings (4) in collecting tanks (5) of the heat exchanger, in which a silicone adhesive is introduced into a respective annular space (6) between the flat tube ends (2) and the openings (4), the silicone adhesive substantially not coming into contact with the medium flowing through the heat exchanger,
    the annular spaces (6) being filled and closed with a silicone adhesive (SK) of the addition-crosslinking type, having a storage modulus in the range of values between approximately 0.1 and 3.0 MPa, by means of a mounting plate (10).
24. Method according to Claim 23, characterized in that the annular spaces (6) are filled to approximately 60 to 95% of their volume with the silicone adhesive (SK).
25. Method according to Claim 23, characterized in that a metered amount of the silicone adhesive (SK) is applied in advance to the mounting plate (10) and is forced into the annular spaces (6) by the bringing together of the mounting plate (10) and the collecting tank (5).
26. Method according to Claim 23, characterized in that the mounting plate (10) has an upright edge (11), which is of such a height that, when the mounting plate (6) is brought together with the collecting tank (5), the edge (11) is first inserted into a corresponding slot (50) within the collecting tank (5) before the forcing-in of the silicone adhesive (SK) is performed.
27. Method according to Claim 23, characterized in that a catalyst is admixed in advance with the silicone adhesive.
28. Method according to Claim 23, characterized in that the flat tube ends (2) are freed for example of fluxes in advance, in order to ensure direct metal contact of the silicone adhesive (SK).
29. Method according to Claim 23, characterized in that the silicone adhesive (SK) either consists of one component or, in preparation for use, is mixed in advance from at least two components.
30. Method according to Claim 23, characterized in that the adhesive connection or the heat exchanger is exposed to a temperature of approximately 80 to 180°C over a time period of 1 to 60 minutes in order to allow the silicone adhesive (SK) to cure.

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