EP1762807B2 - Heat exchanger - Google Patents

Description

The invention relates to a heat exchanger comprising wide and narrow sides, preferably two - piece flat tubes, which are stacked on one another to form channels, in which, for example, a gas, such as exhaust gas or charge air, flows through the flat tubes and, by means of coolant, through the channels flows between the flat tubes, is cooled, wherein a partial housing is formed with a first and a second side and a connecting side, in which the stack of flat tubes is arranged.

A heat exchanger has been disclosed in the recently filed and not yet published European patent application with the application number EP 04 019 339.3 described. It is specifically about an exhaust gas heat exchanger, which should have a bypass.

However, the preamble of the present application is determined by the EP application with the application number 04026647.0 , which is also not pre-published or by the AU-A1-62 556/80 , There, a heat exchanger is described with a part - housing. The flat tubes in most cases consist of welded or drawn tubes. Mainly, when the flat tubes, as shown there, for example in Fig. 20, are composed of two parts, the local heat exchanger is disadvantageous, because the accessibility to the connecting seams for the purpose of preparing the necessary soldering, for example, for the application of solder materials , is not given sufficiently. In an attenuated form, however, this also applies to heat exchangers with one-piece flat tubes.

The US 5,228,515 shows a heat exchanger having a stack of flat tubes. The stack is arranged in a housing, whereby the weight of the heat exchanger is increased.

US 5487424 shows a double wall, heat exchanger. Further prior art is out DE 10359806 A1 as well as out US 2869835 known.

The object of the present invention is to further improve the manufacturability of the heat exchanger having the features of the preamble.

The solution according to the invention is carried out in such a heat exchanger with the characterizing features of claim 1.

The sub-housing is formed as an open profile with a first and a second side and with a connecting side, which comprises only a part of the circumference of the stack of flat tubes, wherein the encompassed part about three sides of the circumference but at least more than 50% until about 90% of the total. In the side of the sub-housing connecting the first side and the second side, at least one cut-out is present, as a result of which the two-part flat-stacked flat tubes are largely accessible in preparation for the soldering process. In the mentioned connecting side is also the inlet and outlet for the coolant flowing in the channels. In the connecting side mentioned, connecting strips remain between the first and the second side (s) in which the inlet and outlet are arranged. The flat tubes are kept at a distance to form the channels. The channels are closed to the outside. For this purpose, the flat tubes have a cross-sectional widening or a raised border. However, it is not preferable but feasible to arrange an additional part between the flat tubes for this function instead of the cross-sectional widening. The design has been further simplified because such a part-housing is much easier to produce, because it can, roughly speaking, be regarded as a sheet with two parallel folds. The flat tubes can be much easier to insert or assemble in such a part-housing. As can be seen, the weight of the heat exchanger is further reduced by the at least one cutout in the connecting side of the partial housing.

Depending on the application, a bypass may or may not be provided in the part of the circumference of the stack of flat tubes not enclosed by the housing. The first and the second side or the legs preferably extend in the direction of the broad sides of the flat tubes and are connected to the broad sides of the outer flat tubes of the stack. In a non-preferred application, the legs extend in the direction of the narrow sides of the flat tubes, in which case the connection is made on the narrow side of a flat tube.

In the preferred application, the flat tubes have a cross-sectional widening extending in the longitudinal direction thereof or a raised border on which the legs are preferably connected to the broad sides of the flat tubes.

The cross-sectional widening can be provided in one or preferably in both broad sides of the flat tubes. It extends like a strip over the entire length of the flat tubes.

The legs or the first and the second side of the sub-housing have a connecting edge, which is preferably formed offset, and preferably takes over the connection with the cross-sectional widening. Thus, a channel for the coolant has also been formed between the housing and the broad side of the outer flat tube.

All flat tubes are preferably formed in two pieces and arranged one above the other, leaving gaps forming the channels, wherein the channels or the interstices are formed by the flat tubes preferably abutting each other with their cross-sectional widening or with their raised border.

The cross-sectional widening is a raised border of the circumference of the parts of the flat tubes. The raised border is interrupted at two points, namely where the entry or exit to / from the channels / s is provided. There are also the mentioned connection strips of the housing, in which corresponding inlet connection or outlet connection are arranged, which therefore correspond with the interruptions in the raised borders, in order to secure the operation.

The raised border is used in each case the connection of two flat tubes, preferably by soldering. Since the adjoining raised borders are wide enough and even, first-class solder joints are to be expected.

The preferably two-piece flat tubes may consist of two identical or of two differently shaped plates, wherein the channels are formed by the deformation of the plates.

There is an inlet header box, and preferably also a separate outlet header box for the gas.

The collecting boxes are equipped with receiving beads for the corresponding section of the connecting edge of the flat tubes.

The flat tubes can have an inner insert. The inner liner is a corrugated sheet whose corrugations preferably form discrete flow passages for the gas.

It is intended to give the heat exchanger formed by the flat tubes, seen in the flow direction of the gas, straight or a curved shape. Also from the curved shape, the invention draws on its peculiarity compared to the known prior art. The proposed part-housing is quite easy to produce for heat exchangers with a curved shape, at least even easier than in the aforementioned prior art, in which the entire connecting side would have to be equipped with a curved contour. According to claim 3 has now been provided to remove the connecting side or replace it with preferably two narrow connecting strips for direct or indirect connection of the first with the second side, which are inserted as a single part, whereby the deformation is simplified. For the purposes of this proposal, a part - housing is also present if the same consists of the mentioned individual parts. It is also contemplated that the heat exchanger having a curved shape is made mimicking the charge air or exhaust gas line, with a gas inlet on one side and a gas outlet on the opposite other side.

The engine compartment of automobiles is known to be characterized by the compact arrangement of the various components. This includes that the exhaust pipes or charge air lines must take a curved course. The above features provide that the heat exchanger partially replaces the mentioned lines, which is to be understood as "mimicking", thereby supporting the compact engine compartment design. (Claim 13)

• Die beigefügte Fig. 7 gehört nicht zur Erfindung.
• Die Fig. 1 zeigt eine Explosionsdarstellung des Wärmetauschers.
• Die Fig. 2 zeigt die Draufsicht auf den Wärmetauscher der Fig. 1.
• Die Fig. 3 zeigt eine perspektivische Ansicht eines Wärmetauschers.
• Die Fig. 4 zeigt eine perspektivische Ansicht eines anderen Wärmetauschers.
• Die Fig. 5 zeigt einen Ausschnitt gemäß Linie V-V in der Fig. 4.
• Die Fig. 6 und 8-15 zeigen perspektivische Ansichten und Schnittdarstellungen eines Wärmetauschers gemäß einer Ausführungsform. Die Schnitte bzw. Ansichten in den Fig. 10 - 15 wurden in der Fig. 9 eingezeichnet, sodass die Abbildungen dem Fachmann völlig verständlich sein sollten.

For other features, reference is made to the other dependent claims. The invention will be described below in two embodiments and independent variants. From this description, additional features and benefits may emerge that may later prove to be particularly important. The invention will be described in connection with exemplary embodiments with reference to the attached drawings.

• The enclosed Fig. 7 does not belong to the invention.
• The Fig. 1 shows an exploded view of the heat exchanger.
• The Fig. 2 shows the top view of the heat exchanger of Fig. 1 ,
• The Fig. 3 shows a perspective view of a heat exchanger.
• The Fig. 4 shows a perspective view of another heat exchanger.
• The Fig. 5 shows a section along line VV in the Fig. 4 ,
• The Fig. 6 and 8-15 show perspective views and sectional views of a heat exchanger according to an embodiment. The cuts or views in the Fig. 10 - 15 were in the Fig. 9 drawn so that the illustrations should be fully understood by the skilled person.

The exemplary embodiments shown in the figures relate to exhaust gas heat exchangers cooled by means of the cooling fluid of the internal combustion engine or else intercoolers for a motor vehicle, which are incorporated into an exhaust gas recirculation system or into a combustion air intake system in a manner not shown, but which does not restrict the said application shall be.

In the exemplary embodiments shown, only three or four flat tubes 3 are stacked on top of each other. The number of flat tubes 3 is optional, or it also depends on the requirements of the particular application. The Fig 1-5 refer to the first embodiment, in which the connection strips 20 are formed integrally with the first 12 and second side 13 . This is especially evident in the Fig. 1 to recognize. There are two connecting strips 20 are provided. In one connecting strip 20 is the inlet 50 and in the other of the outlet 60 , preferably for the cooling liquid of a motor vehicle engine, not shown. Between the two connecting strips 20, which at the same time, as can be seen, represent the connecting side 15 , there is a large central cutout 16. Since the connecting strips 20 are not quite at the front or rear end, it can be said that left and right of the two connecting strips 20 also a respective cutout 16 is provided. The Fig. 1 . 2 and 3 show heat exchanger in which the exhaust gas or the charge air flows through the flat tubes 3 U-shaped, which by the pointing in opposite directions dashed arrows on the left Page in the Fig. 3 and on the right side of the Fig. 2 have been drawn is recognizable. In the Fig. 2 was drawn to the corresponding separation of the flat tubes 3 in the longitudinal direction, only a dashed line. The separation can take place, for example, by means of an inserted separating web 35 , as will be explained later in the text Fig. 15 was indicated or by appropriate deformation of the flat tubes 3 and the flat tube parts 3.1, 3.2. (not shown here)

In contrast, in the Fig. 4 a heat exchanger is shown, the flat tubes 3 are flowed through in a single direction, in the image from left to right, from the exhaust gas or from the charge air. The reference numeral 5 indicates the inlet collecting box and the reference numeral 6 indicates the corresponding outlet collecting box.

The heat exchanger according to Fig. 3 differs from the execution according to the Fig. 1 and 4 furthermore, that in the Fig. 3 the upper flat tube parts 3.1 are pulled cup-like, while the lower parts 3.2 are comparatively flat. Both parts 3.1 and 3.2 are not identical. In the Fig. 4 are the parts 3.1 and 3.2 identical, wherein the connecting edge 2 of the two parts thus extends approximately half the height of the flat tubes 3 , as well as the Fig. 5 shows.

The Fig. 6 and 8-15 show an exemplary embodiment, which differs primarily from the above already partially described embodiment, that there the connection strips 20 are manufactured as individual parts and between the first and second sides 12, 13 are added. This embodiment has the advantage that heat exchangers with a curved design, as in the Fig. 6 and 8-9 shown, easier to represent or manufacture. Such and other irregular shapes, heat exchangers are often advantageous because they can contribute to the compact arrangement in the engine compartment of motor vehicles. In the Fig. 6, 8 and 9 the connection strips 20 have been arranged on the same side of the heat exchanger. The Fig. 6 is different from the Fig. 8 and 9 in that in the Fig. 6 the connection strips 20 are arranged with inlet 50 and outlet 60 on the inwardly facing side and in the Fig. 8 on the outward-facing side. Since these heat exchangers have a part-circle-like contour, "inward" in this context means pointing to an imaginary circle center point and pointing "outwards" from the imaginary circle center point.

Both embodiments mentioned above initially agree that the flat tubes 3 are composed of two flat tube parts 3.1 and 3.2 . The flat tube parts 3.1, 3.2 have a raised edge 30 , which is for example in the Fig. 1 can be seen, which allows a view of the overhead flat tube part 3.1 . The raised border 30 is interrupted at two points. The corresponding posts were in Fig. 1 labeled 40 , and may simply be referred to as the outline border submission 40 . (see also the Fig. 13 ) The two parts 3.1 and 3.2 are assembled to form a flat tube 3 , wherein the two parts 3.1, 3.2 lie with their connection edges 2 to each other, which are bent in the embodiment facing outward. In the exemplary embodiments, tabs 23 (FIG. Fig. 14, 15 ) provided on the connecting edges 2 , which can be bent so that the parts remain stable 3.1 and 3.2 in position to each other and thus later excellent solder joints can arise. The flat tubes 3 thus formed are then stacked, wherein the flat tubes 3 come to rest with their raised edges 30 to each other to each form a channel 10 in the space between two flat tubes 3 . From the figures it can be seen that the height of the sublimity of the border 30 in the exemplary embodiments shown corresponds to approximately half the height of the channel 10 thus formed. In this case, the above-mentioned interruptions 40 are superimposed on one another and, in the region of the interruptions 40, make possible the hydraulic connection to the channels 10 .

It should be noted at this point that in unillustrated embodiments, a raised edge 30 is provided only on one of the two each forming a channel flat tubes, or on one of the two flat tube parts forming a flat tube. In such cases, then the height of the grandeur is equal to the height of the channel 10th

The mentioned hydraulic connection is now provided by the specially designed connecting strips 20 , which are formed with a corresponding inlet 50 and outlet 60 , respectively.

Although the connecting strips 20 are similar per se in both embodiments, there are differences in the production because, as already mentioned, in the first described embodiment, the connecting strips 20 are formed integrally with the first and second sides 12, 13 and in the second Embodiment, the connecting strips 20 as individual parts between the first and second sides 12, 13 are attached. The mentioned production takes place by means of forming machines and corresponding tools (not shown).

The above-mentioned similarity is that the connecting strips are provided with beads 21 20, to comprise the outwardly extending connecting edges 2, each bead 21 in each case two projecting connecting edges 2 of a flat tube 3 accommodating therein. Furthermore, the connecting strips 20 can be formed with lugs 22 , which are each where two flat tubes 3 with their raised border 30 abut each other, extend to lead in the resulting bending radius range to perfect, ie too dense and durable solder joints. (please refer Fig. 5 and / or 12) Zur Fig. 12 must still be emphasized that there the connecting strips 20, the first and the second side 12, 13 connect physically, which should be considered preferred, because so that the connection strip 20 hold together in the manner of a clip, the preassembled items of the heat exchanger to the heat exchanger to prepare for soldering easier. Connecting strips 20 in the sense of the proposed alternative are thus those which are directly connected to the first and the second side 12, 13 . Accordingly, according to this alternative teaching, a sub-housing is to be considered even if it consists of individual parts 12, 13, 20 which are directly connected.

Possible further embodiments of the parts 3.1 and 3.2 of the flat tubes 3 were shown with reference to the second embodiment. The parts 3.1 and 3.2 were provided with formations 33 . Such or other formations may also be present in the first embodiment. However, the formations 33 can also be replaced by means of known inner inserts in order to effect the intended increased durability and turbulence formation in the exhaust gas or in the charge air. In the embodiment according to Fig. 15 the flat tubes 3 were formed with two separate passages 70 , wherein the separation was made by means of a dividing web 35 inserted into the flat tubes 3 , but which, as already mentioned above, by means of continuous formations 33 is also possible.

Another noteworthy training comes from the Fig. 11 which represents the longitudinal section E - E in the region of an inlet 50 or outlet 60 for charge air or exhaust gas. The flat tube parts 3.1 and 3.2 are in this area, which represents the frontal end of the parts 3.1, 3.2 , provided with a deformation 31 , which is intended to optimize the performance of the flow of the incoming charge air or the exhaust gas. The deformation 31 immediately adjoins the raised border 30 and protrudes into the inlet 50 a little.

Finally, it should be pointed out that, although the above proposals have been described in connection with two-piece flat tubes, their conversion into a product is also possible with one-piece flat tubes, such as those shown and described in the aforementioned prior art. Finally, it should be noted that both versions contribute to providing heat exchangers with high-quality solder joints, as they largely ensure accessibility to the solder joints and thus allow their careful preparation for soldering.

Claims (13)

1. Heat exchanger, consisting of flat tubes (3) which have wide and narrow sides (33, 32) and preferably consist of two connected parts (3.1, 3.2) and which are stacked one on the other, so as to form ducts (10), and connected, in which, for example, a gas, such as exhaust gas or charge air, flows through the flat tubes (3) and at the same time is cooled by means of coolant which flows through the ducts (10) between the flat tubes (3), a part-housing (11) with a first and a second side (12, 13) and with a connecting side (15) being formed, in which the stack of flat tubes (3) is arranged, characterized in that that side (15) of the part-housing (11) which connects the first and the second side (12, 13), said part-housing being in the form of an open profile and encompassing only a part of the circumference of the stack of flat tubes, the encompassed part amounting to three sides of the circumference but at least more than 50 to approximately 90% of the overall circumference, has at least one cutout (16), in such a way that at least one connecting strip (20) between the first and second sides (12, 13) is maintained, in which an inlet (50) or an outlet (60) is arranged.
2. Heat exchanger according to Claim 1, characterized in that two connecting strips (20) remain in the connecting side (15), the coolant inlet (50) being arranged in one and the coolant outlet (60) being arranged in the other.
3. Heat exchanger according to Claim 1, characterized in that the connecting side (15) is designed as at least one connecting strip (20) which is attached as an individual part.
4. Heat exchanger according to Claim 3, characterized in that the connecting strips (20) connect the first and the second side (12, 13) to one another directly.
5. Heat exchanger according to Claims 1 and 2, characterized in that the at least one cutout (16) in the connecting side (15) extends up to the first and the second side (12, 13).
6. Heat exchanger according to Claims 1-5, characterized in that the gas flowing in the flat tubes (3) flows through these in one direction, for which purpose an inlet header (5) is arranged on one side of the flat tubes (3) and an outlet header (6) is arranged on the opposite side.
7. Heat exchanger according to one of Claims 1-5, characterized in that the gas flowing in the flat tubes (3) describes a U-shaped path, an inlet header and outlet header (5, 6) being located on one side of the flat tubes (3), and a flow separation (17) being arranged in the flat tubes (3).
8. Heat exchanger according to one of the preceding claims, characterized in that the two parts (3.1, 3.2) of the flats tubes (3) have a border (30) of a raised form which possesses an interruption (40) at at least two locations.
9. Heat exchanger according to one of the preceding claims, characterized in that the connections (4) of the flat tubes (3) are provided in each case on the borders (30) of a raised form, in such a way that, when the flat tubes (3) are being stacked, the interruptions (40) come to lie on two straight lines.
10. Heat exchanger according to one of the preceding claims, characterized in that the connecting strips (20) containing the inlet (50) or outlet (60) match in each case with an interruption (40) of the border (30) of a raised form, in order to be connected hydraulically to the ducts (10) produced inside the border (30) of a raised form.
11. Heat exchanger according to one of the preceding claims, characterized in that the connecting strips (20) have at their mutually opposite margins beads (21) which are suitable in each case for engaging over a connecting margin (2) formed by the two parts (3.1, 3.2) of the flat tubes (3).
12. Heat exchanger according to one of the preceding claims, characterized in that the flat tubes (3) or the heat exchanger formed by the flat tubes have or has a configuration which is straight or curved, as seen in the direction of flow of the gas.
13. Heat exchanger according to one of the preceding claims, characterized in that the heat exchanger having a curved configuration is designed to simulate or partially replace the charge-air or exhaust-gas line, with a gas inflow on one side and with a gas outflow on the other opposite side.

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