DE9315296U1 - Heat exchangers, in particular air / air heat exchangers - Google Patents

Description

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** fteinfriedVrhr. v, Schorlemer

34117 Kassel Brüder-Grimm-Platz 4 DE 6482 Telephone (O561) 1 53 35

Autokühler GmbH & Co. KG ₅ D-34363 Hofgeismar

Heat exchangers, especially air/air heat exchangers

The invention relates to heat exchangers of the types specified in the preambles of claims 1 and 11.

Heat exchangers of this type are mainly known as water or oil coolers in motor vehicles with internal combustion engines and can be manufactured for this purpose with the required high performance in a comparatively small size, especially if the heat exchanger tubes are not provided with circular cross-sections, but rather with oval or fiachoval cross-sections. Another advantage of the heat exchangers described above is that they can be manufactured without using soldering, welding or gluing processes or the like, which are becoming increasingly less desirable for environmental reasons. Various processes are available for this purpose. It is known, for example (DE 33 27 335 Al; DE 34 32 073 Al; US 36 03 384) to introduce support profiles, expansion tools, pressurized gaseous or liquid media or the like into the pipes or into interconnected pipe sections in order to expand them, expand them elastically or fold them out like a hinge, changing their outer contour, and thereby to place the outer walls of the pipes snugly against the surrounding opening edges or the collars attached to them in order to ensure good heat transfer. In addition, it is known (DE 33 02 150 C2) to bring flat oval tubes into good heat-conducting contact with collars attached to the edges of the openings without changing their outer contour by designing these in such a way that they protrude obliquely into the cross-section of the openings before the tubes are inserted and are therefore elastically bent outwards away from them when the tubes are inserted. In contrast to the other methods, the collars and not the tubes are deformed here, whereby large forces have to be applied to insert the tubes into the slats.

In addition, the pipes partially have continuous central partitions to allow both forward and reverse flow of the liquids to be cooled within the pipes.

Such heat exchangers are only suitable to a limited extent for certain applications, e.g. for use as air/air heat exchangers, especially charge air coolers. One main reason for this is that, in terms of the required performance, they are comparable to water or oil coolers on the cooling air side, but on the warm air side, with the same structural design, they require a heat-exchanging surface that is around two and a half times larger. This is the only way to achieve this: the compressed air coming from a turbocharger, for example, is cooled from e.g. 100 to 120° C to e.g. 40 to 60° C before it enters the cylinder in order to increase the engine's performance and improve the engine's combustion efficiency.

The large heat conducting surfaces required result in an undesirable increase in the construction volume of the heat exchanger. This applies even if the heat exchanger tubes are provided with profiles on their insides in a known manner, which slightly increase the heat-exchanging surface (DE 33 02 150 C2). Apart from that, such profiles as well as continuous webs hinder the use of the previously known assembly methods for so-called plug-in heat exchangers, in which the tubes are expanded from the inside by inserting a tool and thus placed against the opening edges or collars.

In contrast, the invention is based on the object of further developing the heat exchangers of the types mentioned at the outset in such a way that they can be manufactured in a simple manner without solder and adhesive and yet can be provided with a large heat-exchanging surface.

The characterizing features of claims 1 and 11 serve to solve this problem.

The invention has the advantages that the heat exchanger tubes can be easily

and preferably by extrusion with large heat-conducting surfaces without the cross-section of the heat exchanger tubes having to be increased accordingly, and that the assembly of a heat exchanger consisting of such tubes is possible simply by inserting one or at least two of these tubes into each opening of the guide plates and then pushing them apart by support profiles inserted between them and thereby bringing them into good heat-conducting contact with the opening edges or the collars attached to them, without the ribs or webs which increase the surface area being a hindrance.

Further advantageous features of the invention emerge from the subclaims.

The invention is explained in more detail below in conjunction with the accompanying drawings using exemplary embodiments. They show:

Fig. 1 is a schematic, perspective view of a heat exchanger according to the invention;

Fig. 2 and 3 show schematic cross sections through a pair of heat exchanger tubes inserted into an opening of a baffle in the unfastened and fastened state;

Fig. 4 is an enlarged partial section corresponding to Fig. 2;

Fig. 5 and 6 are views corresponding to Fig. 2 and 3 of a second embodiment of the invention;

Fig. 7 to 10 cross sections through various embodiments of the heat exchanger tubes according to the invention;

Fig. 11 is a view corresponding to Fig. 6 of a further embodiment of the invention;

Fig. 12 shows an enlarged partial section corresponding to Fig. 4 through a further embodiment of the heat exchanger according to the invention;

Fig. 13 and 14 show schematic cross sections corresponding to Fig. 2 and 3 through a pair of heat exchanger tubes inserted into an opening of a baffle in the unfastened and fastened state, respectively, according to a further embodiment of the invention;

Fig. 15 a cross-section through a variant of the embodiment according to Fig. 13 and 14; 10

Fig. 16 is a cross-section through another embodiment of the invention; and

Fig. 17 to 20 sections through two further embodiments of the invention, each before and after final assembly.

The single-row heat exchanger shown in Fig. 1 to 3 is designed in the manner of a conventional tube cooler. It contains a number of parallel and spaced-apart, plate-shaped guide plates 1, each of which has a row of openings 2 (Fig. 2) which are arranged coaxially when the guide plates 1 are stacked and have an essentially rhombic cross-section in the exemplary embodiment. The edges of the guide plates 1 which delimit the openings 2 are extended by coaxial collars 3 of corresponding cross-section. The openings 2 and collars 3 are penetrated by tubes 4a and 4b arranged perpendicular to the guide plates 1, which overall have a cross-section corresponding to the cross-section of the openings 2 and collars 3. The upper and lower ends of the pipes 4a,b protrude through corresponding openings in a base plate 5 or 6 and are connected along their entire circumference to collars 7 of these openings in a liquid-tight or gas-tight manner. A conventional collecting box 8 is attached to the lower base plate 6, which has a connection 9 for the supply or discharge of the medium flowing through the pipes 4a,b, e.g. air. A corresponding collecting box (not shown) is connected to the upper base plate 5.

The guide plates 1 and pipes 4a,b form a heat exchanger network 10, which is installed in the heat exchanger without soldering, welding, adhesive or similar connections by simply mechanically bracing the pipes 4a,b.

Openings 2 and collars 3 are made. The two preferably identical tubes 4a and 4b are provided with cross-sections in the manner of isosceles triangles and in particular with relatively narrow base sections 1 la,b and two side walls 12a,b and 13a,b extending from their ends, the free ends of which are connected to one another so that closed tubes are formed. The two tubes 4a,b are arranged in the openings 2 in such a way that their base sections 1 la,b are directly opposite one another and both tubes 4a,b together have an essentially rhombic cross-section. Additional support profiles 14 (Fig. 3) are used to brace the pipes 4a,b in the openings 2, preferably extending over the entire length of the pipes 4a,b. These support profiles are inserted between the base sections 11a,b into the openings 2, thereby pushing them apart in the direction of a double arrow v (Fig. 2) and perpendicular to their direction of extension, and thereby displacing the two pipes 4a,b as a whole in such a way that the outer sides of their side walls 12a,b and 13a,b are pressed against the edges of the openings 2 and the collars 3 attached to them. The outer contours of the side walls 12a,b and 13a,b of the pipes 4a,b are in accordance with Fig.

and 3 are preferably adapted to the inner contours of the collars 3 in such a way that, when the tubes 4a,b are spread out (Fig. 3), they fit snugly against the collars 3 and are connected to them in a way that conducts heat well. The support profiles 14 preferably have a slight oversize so that the collars 3 are under a slight elastic prestress when assembled and the heat-conducting contact with the tubes 4a,b is maintained even when the heat exchangers are in operation.

An advantage of the described arrangement is that the tubes 4a,b are spread or pressed apart as a whole and their cross-sections or shapes remain unchanged over the entire length. Since the cross-sections of the openings 2 or collars 3 also remain essentially unchanged, only as much force is required when inserting the support profiles 14 as is necessary to ensure a permanently good press fit.

According to Fig. 1 to 4, the openings 2 preferably have a smallest diameter a (Fig. 4) parallel to the base sections 1 la,b and a largest diameter b perpendicular to this, whereby the arrangement is expediently symmetrical, analogous to oval cross-sections, such that the smallest and largest diameters lie exactly in an associated axis of symmetry of the rhombus shape. In a preferred embodiment, the smallest diameter a is e.g. 16 mm and the largest diameter b is e.g. 61.9 mm, whereby the side surfaces of the openings

edges or the collar 3 with the largest diameter b form a flank angle α of 4°. The two tubes 4a,b, on the other hand, have base sections 1la,b with a length of 7.7 mm measured in the direction of the smallest diameter a and side walls with a height of 28.8 mm measured in the direction of the largest diameter b, so that between the side walls 12a,b and 13a,b and the associated side surfaces of the collar 3 there is a circumferential gap with a width c of approximately 0.15 mm, while at the same time a displacement d of 2.15 mm each parallel to the diameter b is possible until it rests on the collar 3. In order to obtain a slight elastic spreading of the collar 3, the thickness of the support profiles 14 measured in the direction of the largest diameter b is set to 6.3 mm, for example. In addition, the openings 2, collars 3 and tubes 4a,b are preferably rounded at the ends of the largest diameter b according to Fig. 4 and spaced by a dimension e (Fig. 4) which allows the desired displacement of the tubes 4a,b.

The expansion of the two pipes 4a,b can be carried out either directly by the support profile 14 or by a tool, which the support profile is immediately pushed along, as is known for the radial expansion of pipes (DE 34 32 073 Al).

According to Fig. 2 and 3, the tubes 4a,b are provided on their inner sides with numerous means in the form of inwardly projecting, "open" ribs 15 or the like, which increase the heat-exchanging surface and thereby, in comparison to tubes without these means, bring about a considerable increase in the total area available for heat exchange. The ribs 15 etc. can be arranged parallel to the base section 11a or 11b, but also diagonally or perpendicularly to it. Open ribs 15 are understood to mean in particular those means which protrude inwards from the inner surfaces of the tubes and have free ends arranged somewhere inside the tube. In addition, continuous or "closed" webs or ribs 16 can also be provided as means which increase the heat-conducting surface. Such webs 16, however, also connect two pipe walls together, whereby these webs 16 can also be arranged parallel to the base sections 11a,b or, as indicated in Fig. 11 for webs 17 of pipes 18a,b, obliquely or perpendicularly thereto. The webs 16,17 divide the pipes into two or more chambers 19 (Fig. 2) or 20 (Fig. 11). In addition, the webs 16,17 have the additional advantage over the ribs 15 that they stiffen and stabilize the pipes, so that

in particular, their side walls 12a,b and 13a,b do not have the tendency, even when assembled, to collapse or to assume a circular cross-section when a medium under pressure is passed through, thereby impairing the good heat-conducting contact with the collar 3. The webs 16,17 and ribs 15 also allow the pipes 4a,b to be provided in chambers with different shapes and cross-sections, but with the same "hydraulic diameters" to achieve uniform media exposure across the entire pipe cross-section.

The described pipes 4a,b and 18a,b and the other pipes described below are conveniently manufactured by extrusion. Aluminum is a suitable material for the pipes.

The two pipes 4a,b can, as shown in Fig. 5 and 6, be connected to one another by material bridges 21 to form one-piece profiles. In this case, the material bridges 21 are expediently V-shaped or similar during manufacture, or shaped in such a way that they form a material reserve which is only straightened or smoothed when the pipes 4a,b are spread, but is not subjected to significant stretching. For this purpose, the wall thickness of the material bridges 21 is also expediently comparatively small and at least smaller than in the adjacent pipe sections, e.g. the base sections 11a and 11b. In order to safely transmit the spreading and supporting forces applied with the support profiles 14, it is possible to stiffen the pipes 4a,b in the area of the base sections 11a,b by special measures. For example, reinforcing webs 22 can be provided to connect the base sections to other wall sections (Fig. 7). Alternatively, concavely curved base sections 23 can be provided and the support profiles 14 can be provided with correspondingly concavely curved support surfaces 24 (Fig. 8). It would also be possible to design the base sections according to Fig. 9 not as continuous, but with the help of spaced, wedge-shaped widened support feet 25.

The support profiles 14 are suitably dimensioned in the case of separate pipes 4a,b so that they essentially fill the cross-section of the openings 2 or collar 3 that remains free between them when assembled (Fig. 3). In this case, according to Fig. 10, support profiles 26 made of hollow profiles can also be provided, which form continuous channels, transport air to be cooled and can therefore participate in the heat transfer. Alternatively,

In the case of pipes 4a,b or 18a,b connected by material bridges 21 or 27 (Fig. 5, 6 or 11), it is possible to provide support profiles 28 or 29 which have smaller cross-sections than the remaining free cross-sections of the openings 2. In this case, for example, the material bridges 21 together with the base sections 11a,b delimit additional channels surrounding the support profiles 28 for additional air guidance or heat transfer. The same applies to the embodiment according to Fig. 11, in which base sections 30a,b are also provided with recesses intended to accommodate the ends of the support profiles 29.

Fig. 12 shows an embodiment in which the gap (dimension c in Fig. 4) between the tubes 4a,b and the collars 3 in the non-expanded state is smaller near the center of the openings 2 (dimension C ₁ ) than in the area of the ends of the largest diameter (dimension C ₂ ). This allows a more uniform elastic support of the spreading forces and thus also a better attachment of the tubes to the collar and better heat conduction to be achieved.

Fig. 13 and 14 show an embodiment in which guide plates 31 are provided with openings 32 and collars 33, which have so-called flat oval cross sections, i.e. at the ends of the largest diameters they are provided with semicircular or otherwise shaped sections and in between with the smallest diameter, essentially straight sections. Two tubes 34a,b are inserted into the openings 32 or collars 33, which preferably have essentially the same cross sections, whereby these cross sections are each somewhat smaller than half the cross sections of the openings 32, if these are thought to be divided by the plane of symmetry that contains the largest diameter. To spread or push apart these tubes 34a,b, support profiles 35 (Fig. 14) are used which, in contrast to the embodiments according to Fig. 1 to 12, are not effective in the direction of the largest diameter, but in the direction of the smallest diameter or a double arrow w (Fig. 13) and thereby press the tubes 34a,b against the broad sides of the opening edges or collars 33. The tubes 34a,b can also be designed analogously to the tubes 4a,b or 18a,b according to Fig. 1 to 12 and in particular can be connected to form one-piece profiles by material bridges 36 (Fig. 15).

The heat exchangers described can be manufactured in the following way:

For heat exchangers with two separate tubes spread by means of the support profile 14 or 35 (Fig. 2 to 4 or 13 and 14), it is recommended to first produce the finished heat exchanger network according to the reference number 10 in Fig. 1 and then to pull on the base plates 5 or 6 with closely toleranced openings corresponding to the tube cross-sections and to seal them, for example, with casting compound. The length of the support profiles is preferably dimensioned such that they do not protrude through the base plates 5 or 6. If, however, it is a heat exchanger with pipes made in one piece and spread by the support profiles 28 or 29 according to Fig. 5, 6 or 11, then the base plates 5, 6 can be installed at the same time as the guide plates 1, whereby the pipes in the openings in the base plates can in turn be sealed. This is particularly advantageous because in this case the channels located next to the support profiles 28 or 29 according to Fig. 5, 6 or 11 or the hollow support profiles 26 according to Fig. 10 can also be connected to the collecting boxes. Apart from that, in both cases it is possible to provide seals in the openings in the base plates instead of sealing them with casting compound.

In order to make it easier to insert the pipes into the packages consisting of the guide plates 1 and, if applicable, the base plates with the smallest possible gaps, the pipes can be tapered at one end by pressing from the outside. This also eliminates the snagging effect of any cutting burrs. In a similar way, the support profiles could also be provided with insertion bevels at one end.

Particular advantages of the described tubes, which can be produced by extrusion, are that they have a high degree of dimensional stability, a large inner surface and yet low air resistance due to the ribs 15 and webs 16 and 17, and can be produced inexpensively. If it is also desired to provide the tubes with internal means for air turbulence, this could be done in a manner known per se by providing their side walls 12a,b and 13a,b with kinks produced by embossing.

In the embodiment according to Fig. 16, pipes 38 with oval or similar cross-sections or with rhombus-like cross-sections are preferably provided, which, analogous to Fig. 4, have a smallest diameter a and a largest diameter running expediently perpendicular to it.

diameter b. The tubes are provided on their inside with numerous means in the form of inwardly projecting, open ribs 39 or the like, which increase the heat-exchanging surface and thereby, in comparison to tubes without these means, bring about a considerable increase in the total area available for heat exchange. The ribs 39 are arranged at least partially parallel to the smallest diameter a, but do not run through to the largest diameter b, so that a gap remains between ribs 15 projecting from opposite broad sides. The external cross section of the tubes 38 is somewhat smaller than that of the associated openings in the guide plates designed analogously to Fig. 1 to 15, which are not shown separately again in Fig. 16.

Support profiles 40 are used to create good heat-conducting contact with the opening edges or collars of the guide plates. These are inserted into the gap remaining between the free ends of the ribs 39 and have a length that essentially corresponds at least to the length of the tubes 38 within the heat exchanger network. The support profiles 40 have a width that is slightly larger than the largest diameter b of the tubes 38 and a thickness that is significantly smaller than the smallest diameter a of the tubes 38. The support plates 40 are thus used to be inserted into the tubes 38 themselves, in contrast to Fig. 1 to 15, and to create the desired good heat-conducting contact between the tubes 38 and the guide plates, in a different way than usual, by spreading the tubes 38 parallel to the largest diameter b. To support the support profiles 40, support surfaces 41 can be provided which are attached to the inner sides of the ends of the tubes 38 having the smallest radii of curvature.

In order to prevent the tubes 38 from collapsing in the area of their broad sides in the direction of the smallest diameter a, the free ends of the ribs 39 preferably end at an imaginary gap running in the direction of the longest diameter b and arranged symmetrically within the tube, the thickness of which is equal to the thickness of the support profile 40. When the tube 38 is expanded in the direction of the large diameter b, the free ends of the ribs 39 rest against the broad sides of the support profile 40 and thereby prevent the tubes 38 from collapsing, without simultaneously causing the tubes 38 to expand in the direction of the smallest diameter a. This results in favorable friction conditions even when

if a large number of such fins 39 are provided over the entire length of the large diameter b. In addition, the tubes 38 can have further fins 42 which increase the heat exchange surface and which are shorter than the fins 39 in the direction of the smallest diameter a and therefore do not contribute to preventing the collapse of the tubes 38. 5

The support profiles 40 are expediently provided in a manner known per se with windows and/or gills and/or other means 43 in order to thereby generate turbulence within the medium flowing through the pipes 38.

Furthermore, the advantages that can be achieved with the tubes 38 and support profiles 40 are analogous to those that can be achieved with the tubes and support profiles explained above according to Fig. 1 to 15. In particular, the tubes 38 can be provided with material bridges 21 and 36 corresponding to Fig. 5, 6 and 13, serving essentially the same purpose and preferably having a V-shape or similar shape.

In the embodiment according to Fig. 17 and 18, analogous to Fig. 16, tubes 45 produced by extrusion with oval or similar or rhombus-like or flat oval cross sections are provided, which, analogous to Fig. 16, have a smallest diameter a and a largest diameter b that is expediently perpendicular to it. The tubes 45 are provided on the inside of their broad sides 46 and 47 with numerous ribs 48 and 49 or similar to increase the heat-exchanging surface. The ribs 48 and 49 are "open", i.e. they end in the interior of the tube without running through to the opposite inner side.

In addition, the tubes 45 preferably have two "closed" ribs 50 and 51 in a middle part, which are spaced apart from one another and are designed to run continuously from one inner side to the opposite inner side and therefore firmly connect the opposing broad sides 46 and 47 to one another. As Fig. 17 shows, the two closed ribs 50 and 51 are provided with a material reserve 50a, 51a in the form of a bead, a groove or the like in the state of the tubes 45 that results after extrusion. Corresponding material reserves 52a, 53a are also expediently designed in two opposing sections 52 and 53 of the broad sides 46 and 47. The sections

-19-

52,53 and the closed ribs 50,51 form a channel 54 that runs along the entire length of the pipe and is closed on all sides.

To create a good heat-conducting contact with opening edges 55 or collars of guide plates 56, tools 57 in the form of mandrels or the like (Fig. 18) are used, which are pulled or pushed through the tubes 45 after the tubes 45 have been inserted into the openings of the guide plates 56 in order to expand them and place them against the opening edges 55 or collars. The outer contour of the tools 57 is selected so that it corresponds to the contour that the channel 54 should have after the material reserves 50a to 53a have been pressed out. In addition, as shown in particular in Fig. 18, the arrangement is such that after the tools 57 are pulled through the tubes 45, the closed ribs 50 and 51 assume a largely straight, elongated shape and thereby reliably prevent the broad sides 46 and 47 from collapsing in the direction of the smallest diameter a after the expansion process. Finally, the arrangement is also such that by pressing out the material reserves 52a, 53a from the sections 52, 53 of the broad sides 46 and 47, the tube halves located on both sides of the smallest diameter a are displaced parallel to the largest diameter b and are thereby pressed along their entire circumferential surface against the opening edges 55 or collar. In this case, sections 52 and 53 are expediently drawn into a substantially straight or slightly curved shape according to the shape of the pipe (Fig. 18), so that the pipes 45 cannot collapse in the direction of their largest diameter b. The ribs 50, 51 are therefore created - in the fully assembled state - by pressing out the material reserves 50a, 51a provided in them. The same applies to sections 52 and 53.

In the embodiment according to Fig. 19 and 20, which essentially corresponds to the embodiment according to Fig. 17 and 18, flat oval instead of rhombus-shaped tubes 60 are shown, which can also have other cross-sectional shapes and are again provided with a smallest and largest diameter a and b respectively and with two opposing broad sides 61 and 62. Furthermore, in a middle part of the tubes 60 there is a continuous, all-round closed channel 63, which is delimited by two closed ribs 64 and 65 and two sections 66 and 67 of the broad sides 61 and 62. In contrast to Fig. 17 and 18, after the extrusion process only the ribs 64, 65 have material reserves 64a and 65a, while the sections 66, 67 essentially already have the shape that they also have in the finished

11 · · * &iacgr;&idgr;&iacgr; * "I « J

Accept heat exchangers.

Preferably at the ends of the largest diameter b, the tubes 60 each have a further continuous and closed channel 68 and 69, which is delimited by two further sections 70, 71 and 72, 73 of the broad sides 61 and 62 of the tubes 60. Each section 70 to 73 has a material reserve 70a to 73a in the form of a bead, groove or the like. In addition, the channels 68 and 69 are delimited by the curved wall sections provided at the ends of the longest diameter and by a closed rib 74 and 75, respectively, which, like the ribs 63, 64, can be provided with material reserves 74a and 75a, respectively.

To produce the finished heat exchanger network, the tubes 60 are inserted into openings 76 of guide plates 77 and spread or expanded using tools analogous to Fig. 17 and 18. Such a tool 78 is arranged in the channel 68 in Fig. 20. In contrast to Fig. 17 and 18, here the outer walls of the tubes 60 are pressed against the edges or collars of the openings 76 using several tools 78, whereby the tools inserted into the channels 68 and 69 cause the tubes 60 to expand essentially parallel to the largest diameter b and thereby press out the material reserves 70a to 73a until the sections 70 to 73 assume an essentially elongated shape. At the same time, the tools 78 also press the material reserves 74a, 75a out of the ribs 74, 75, so that the broad sides 61, 62 are also pressed firmly against the edges or collars of the openings 76. In the same way, the material reserves 64a, 65a are pressed out of the ribs 64, 65 by pulling or pushing an appropriate tool through the channel 63. After all the material reserves have been pressed out, the stretched ribs 64, 65 and 74, 75 then prevent the tubes 60 or the broad sides 61 and 62 from collapsing parallel to the smallest diameter a, analogous to Fig. 17 and 18.

Otherwise, the purpose and function of the embodiments according to Fig. 17 to 20 are analogous to those according to Fig. 1 to 16.
30

The invention is not limited to the embodiments described, which can be modified in four ways. This applies in particular to the embodiments shown in the drawings.

cross sections of the openings, collars and tubes, since a displacement of the tubes in opposite directions can also be achieved with other cross sections, in particular essentially oval cross sections. The use of tubes with identical cross sections in pairs is also not absolutely necessary. Furthermore, the invention is not necessarily limited to the use of two tubes per opening of the guide plates 1, since on the one hand the support profile according to Fig. 10 can itself be designed as a tube and on the other hand embodiments are conceivable in which, for example, three or more tubes lying next to one another and support profiles lying between them are provided. Furthermore, the opening edges or collars can be adapted to the support profiles where the support profiles come to lie, or conversely the support profiles can be adapted to the opening edges or collars, as is indicated for example in Fig. 4 by straight collar sections. Finally, in the embodiments according to Fig. 17 to 20, any appropriate and in individual cases desired number and arrangement of open or closed ribs is possible. It is understood that the individual features of all embodiments according to Fig.

up to 20 can also be provided in combinations other than those shown.

Claims (20)

ic · &idigr; * * &idigr;&iacgr; * "&Iacgr;. Claims 1. Heat exchanger, in particular air/air heat exchanger, with a plurality of parallel and spaced-apart baffles (1,31) having openings (2,32) with non-circular cross-sections, as well as pipes running perpendicularly thereto, passing through the openings (2,32) and having corresponding cross-sections, the outer walls of which are pressed against the opening edges or collars (3,33) attached to them without the use of a solder, welding or adhesive or the like, characterized in that the openings (2,32) are penetrated by at least two pipes each (4a,b; 18a,b; 34a,b) which have inwardly projecting ribs (15) and/or webs (16,17) which considerably increase the heat exchange surface, and in that between these pipes (4a,b; 18a,b; 34a,b) support profiles (14,26,28,29,35) are arranged, which keep the tubes (4a,b; 18a,b; 34a,b) at a distance and press their outer walls against the opening edges or collars (3,33). 2. Heat exchanger according to claim 1, characterized in that the openings (2,32) are penetrated by two tubes (4a,b; 18a,b; 34a,b) with the same cross-sections. 3. Heat exchanger according to claim 2, characterized in that the openings (2) have rhombic cross-sections, that the tubes (4a,b; 18a,b) are provided with triangular cross-sections and are placed opposite one another with base sections (11a,b; 30a,b) in such a way that they, both together, result in a substantially rhombus-like outer contour, and that the support profiles (14,26,28,29) are arranged between the opposing base sections (11a,b; 30a,b). 4. Heat exchanger according to claim 3, characterized in that the support profiles (14,26,28,29) are effective in the direction of the largest diameter of the openings (2). • » · it ·» 5. Heat exchanger according to claim 2, characterized in that the openings (32) have flat-oval cross-sections, the tubes (34a, b) are provided with cross-sections adapted thereto and are positioned opposite one another essentially along base sections which run parallel to the largest diameters of the flat-oval openings (32) in such a way that they, both together, result in an essentially flat-oval outer contour, and that the support profiles (35) are arranged between the opposing base surfaces. 6. Heat exchanger according to claim 5, characterized in that the support profiles (35) are effective in the direction of the smallest diameters of the openings (32). 7. Heat exchanger according to one of claims 1 to 6, characterized in that the webs (16, 17) are designed such that the interior spaces of the tubes (4a, b; 18a, b; 34a, b) are divided into at least two chambers running parallel to their longitudinal axes and sealed against one another. 8. Heat exchanger according to one of claims 1 to 7, characterized in that the webs (16,17) are designed such that they connect at least two opposite wall parts of the tubes (4a,b; 18a,b; 34a,b) to one another. 9. Heat exchanger according to claim 8, characterized in that the wall parts run parallel to the largest diameters of the openings (2,32). 10. Heat exchanger according to one of claims 1 to 9, characterized in that the tubes (4a,b; 18a,b; 34a,b) are connected to one another by material bridges (21,27,36) which are preferably thinner than the tube walls. 11. Heat exchanger, in particular air/air heat exchanger, with a plurality of parallel and spaced-apart baffles having openings (76) with non-circular cross-sections and tubes (38, 45, 60) running perpendicularly thereto, protruding through the openings and having corresponding cross-sections, the outer walls of which can be bonded against the opening edges (55) without the use of a soldering, welding or adhesive agent or the like. _&idiag;7- or collars attached to them, characterized in that the openings (76) are each penetrated by a tube (38,45,60) which has open and/or closed ribs (39,48,49,50,51,64,65,74,75) projecting inwards and considerably increasing the heat exchange surface, and in that the outer walls of the tubes (38,45,60) are pressed against the opening edges (55) or collars by support profiles (40) arranged between open ribs (39) or by pressing out material reserves (50a,51a,64a,65a,74a,75a) provided in the broad sides (46,47,61,62) and in closed ribs (50,51,64,65,74,75), whereby collapse of the tubes (38,45,60) in the direction of their smallest diameter (a) is prevented by the free ends of open ribs (39) resting on the support profiles (40) or by pressed-out, closed ribs (50,51,64,65,74,75). 12. Heat exchanger according to claim 11, characterized in that the fins (39,48,49,50,51,64,65,74,75) run parallel to the smallest diameters (a) of the tubes (38,45,60). 13. Heat exchanger according to claim 11 or 12, characterized in that the Tubes (38) have further inwardly projecting ribs (42) which are not involved in preventing collapse. 14. Heat exchanger according to one of claims 11 to 13, characterized in that the support profiles (40) are provided with means (43) serving to create turbulence. 15. Heat exchanger according to one of claims 11 to 14, characterized in that tubes (45, 60) are provided with at least one continuous channel (54, 63) each, which is delimited by two opposing broad side sections (52, 53, 66, 67) and by two likewise opposing, closed ribs (50, 51, 64, 65) which prevent the tubes (45, 60) from collapsing in the direction of their smallest diameter (a), which are created by pressing out material reserves (50a, 51a, 64a, 65a) provided in them. 16. Heat exchanger according to claim 15, characterized in that the two broad side sections (52, 53) are also created by printing out material reserves (52a, 53a) provided in them. - is- A 17. Heat exchanger according to claim 15 or 16, characterized in that the channels (54,63) are arranged in the tube centers. 18. Heat exchanger according to one of claims 15 to 17, characterized in that tubes each having a continuous channel (68, 69) are provided at the ends of their longest diameters (b), said channel (68, 69) being delimited by at least two opposing broad side sections (70, 71, 72, 73) which are created by pressing out material reserves (70a, 71a, 72a, 73a) provided in them. 19. Heat exchanger according to one of claims 15 to 18, characterized in that it has further closed ribs (74,75) preventing the collapse of the broad sides (61,62).
which have been created by expressing material reserves (74a,75a) provided in them. 20. Heat exchanger according to one of claims 1 to 19, characterized in that the tubes (4a,b;18a,b;34a,b;38;45;60) are produced by extrusion.