EP1804989A1

EP1804989A1 - Method for producing a heat exchanger

Info

Publication number: EP1804989A1
Application number: EP05795075A
Authority: EP
Inventors: Michael Kranich; Klaus KÜBLER; Karl-Heinz Staffa; Christoph Walter
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2004-10-05
Filing date: 2005-10-05
Publication date: 2007-07-11
Also published as: US20080029258A1; WO2006037616A1; DE102004048767A1

Abstract

The invention relates to a method for producing a heat exchanger (1), in particular for a motor vehicle. The invention is characterised in that a sub-assembly consisting of the two connection pipes (4) that supply or evacuate the coolant and at least the upper panel (3) or surface of the heat exchanger (1), which contains the openings associated with the connection pipes (4), are positioned, mechanically pre-assembled and then, together with the remaining heat exchanger (1) parts to be soldered, are soldered in a common work operation. The invention also relates to a heat exchanger (1) that is produced according to said method.

Description

Process for the preparation of a heat exchanger

The invention relates to a method for producing a heat exchanger, in particular for ventilation, heating or air conditioning systems in a motor vehicle, which is operable at high internal pressures, according to the preamble of claim 1.

From DE 102 60 107 A1 discloses a heat exchanger for an air conditioner of a motor vehicle is known, in which can be used as refrigerant R134a or R744, wherein the individual components are so firmly material, force and / or positively connected with each other that the Inner space of the components even at high pressures up to 300 bar gas and / or liquid-tight against an environment of the heat exchanger.

Usually, the production of a heat exchanger takes place by the individual parts, ie in particular collectors, flat tubes and arranged therebetween corrugated fins are assembled and soldered. The connection pipes to be connected to the collector, through which the refrigerant can be supplied or removed, are usually positioned only after the heat exchanger has been soldered and, where appropriate, by means of bonding. soldered, welded or fastened, for example, with the help of Lokringen. This is particularly difficult for heat exchangers with small depths, ie of 40 mm and smaller, and the associated cramped spatial conditions. Furthermore, the heat exchanger surface can be impaired.

Based on this prior art, the object of the invention is to provide a heat exchanger which is improved in particular with regard to the production process. This object is achieved by a method for producing a heat exchanger with the features of claim 1. Advantageous embodiments are the subject of Unteransprü¬ che.

According to the invention for producing a heat exchanger, in particular for a motor vehicle, an assembly consisting of the two the refrigerant inlet or outlet connecting pipes and at least the ober¬ most plate of the heat exchanger, in which belonging to the connection pipes openings, wherein at least one opening each connecting pipe is provided, are provided, positioned and mechanically preassembled, and soldered after assembly with the other parts of the heat exchanger to be soldered in a single joint operation. The heat exchanger tubes, which are in particular flat tubes, and corrugated ribs are conventionally encapsulated before soldering, the positioned and prefixed assembly is attached, and all components are soldered in one operation, so that the previously usual additional operations for subsequent soldering of the connection pipes to the collector etc. omitted. The term "plate" is to be construed broadly and is intended to include similar embodiments, according to which the collector is not necessarily formed by flat plates, so that the same may well be formed substantially in one piece and by a hollow profile. The heat exchanger is preferably designed for operating pressures of 90 bar, preferably at least 50 bar, so that R744, ie CO ₂ , can be used as the refrigerant.

The connecting pipes are preferably positioned and preassembled during pre-assembly at least on the outermost plate by means of one or more clamps. This clip connection for prefixing is particularly suitable for heat exchangers with a low overall depth, since the forces acting on the brackets compared to the forces acting on the brackets in heat exchangers of great depth are relatively low. The clip hin¬ preferably engages all the collector forming plates.

The connection pipes are alternatively or additionally attached during pre-assembly by means of pins. These pins are here inserted in openings provided in the plate or plates and openings provided in the connecting tubes. In this case, the pins are preferably solder-plated, so that the pins are soldered in the openings during the soldering process, whereby the gaps between the pins and inner lateral surfaces of the openings are sealed, so that no leakage is possible.

The connecting pipes are alternatively or additionally mounted during pre-assembly on outwardly projecting passages, to which openings of the connecting pipes are placed. Here, the self-locking is sufficient for a sufficiently secure connection. The passages preferably remain open and serve as a refrigerant supply or discharge. At least one passage is provided per connecting tube, preferably two or more passages are provided per connecting tube.

The connecting pipes are used alternatively or additionally in the pre-assembly with the help of solder joints between the connecting pipes and the outermost

Prefixed plate. These may be solder joints that have a - A - have significantly lower melting temperature, as the final Löt¬ connections. The solder joints for the prefixing are preferably formed spatially limited.

The connecting pipes are alternatively or additionally pre-fixed in the pre-assembly with the help of at least one side part, which projects beyond the Anschluß¬ pipes, and in each connection pipe a passage is formed through which the corresponding connection pipe inserted and with the aid of which it is prefixed.

For prefixing, additionally or alternatively, the outermost plate may have protruding tabs on which the connecting tubes are prefixed, in particular by means of stapling.

Before the pre-assembly, at least the outermost plate in the area of the installation of the connection pipes or the connection pipes in the area of the system are solder-plated to the outermost plate, whereby additional operations can be eliminated.

In the following the invention will be explained in detail by means of embodiments with reference to the drawing. Show it:

1 shows a schematically illustrated section through the upper region of a heat exchanger according to the first exemplary embodiment,

2 shows a schematically represented section through the upper region of a heat exchanger according to the second exemplary embodiment, FIG. 3 shows a schematically illustrated section through the upper region of a heat exchanger according to the third embodiment,

Fig. 4 is a schematically illustrated section through the upper

Area of a heat exchanger according to the fourth exemplary embodiment,

5 shows a schematically illustrated section through the upper region of a heat exchanger according to the fifth exemplary embodiment, FIG.

Fig. 6 is a schematic plan view of the top plate without

Connecting pipes according to the sixth embodiment,

7 shows a schematic plan view to illustrate a first embodiment with respect to the tube arrangement on the heat exchanger, and FIG

Fig. 8 is a schematic, partially illustrated plan view for Ver¬ clarification of a second embodiment with respect to the connection pipe arrangement on the heat exchanger.

The disclosure content of DE 102 60 107 A1, in particular also with regard to the general structure of a heat exchanger, of the usable materials described herein, such as, for example, aluminum, aluminum alloys, the usable refrigerant, such as Carbon dioxide, R 134a, nitrogen, oxygen, air, Kohlen¬ hydrogens, and the dimensions of the heat exchanger described, expressly included. A designed for operating pressures of 60 bar heat exchanger 1 a motor vehicle air conditioning system, which is not shown in detail, by a plurality of a collector 2 forming plates 3, in the present U-shaped ge bent flat tubes (not shown), in a known manner between the different chambers of the collector 2 are arranged, and between the flat tubes arranged corrugated ribs (not shown) formed. Here, the embodiment just described according to the six embodiments described below is the same. In the present case, to protect the outermost corrugated ribs, ie in the viewing direction of FIGS. 7 and 8, two different embodiments of the connecting tubes 4 are shown, namely once with a parallel flow direction (FIG. 7) and once with an opposite flow direction (FIG ) of the refrigerant (indicated by arrows), plate-shaped side parts 5 are arranged, which are relevant only in the case of the fifth embodiment described later with reference to FIG. 5 fifth embodiment for the connection pipe side region of the heat exchanger. In the other embodiments, the side parts only reach a maximum of the end of the collector 2, so that they are not visible in the detail shown in FIGS. 1 to 5.

According to the first exemplary embodiment illustrated in FIG. 1, the two connecting tubes 4 are positioned and prefixed on the plates 3 forming the collector 2 by means of a plurality of clamps 10, whereby an assembly consisting of the connecting tubes 4 and the plates 3 is formed. This assembly, together with the clamps 10, is mounted on the remaining parts of the heat exchanger assembly, ie in particular on the flat tubes and corrugated ribs, and is prefixed. Subsequently, the parts of the assembly are soldered to each other and with the other parts of the heat exchanger 1 in one operation. As shown in FIG. 1, the clamp 10 has a shape adapted to the nominal position of the connection pipes 4. The clamp 10 engages behind the bottom of the plates 2 forming the collector 2 and braces the two connecting pipes 4, which automatically align themselves in the U-shaped depressions, against the outermost of the plates 2 forming the collector 2, so that they can not move in conjunction with the shape of the clip 10.

In the present case, both the connecting pipes 4 and the plates 3 are soldered, so that the solder melts in the soldering furnace and the parts mentioned, as well as the remaining parts of the heat exchanger 1 are firmly connected to each other in a single operation and a relatively large-area connection between the Connecting pipes 4 and the outermost plate 3 is ensured.

According to the second exemplary embodiment illustrated in FIG. 2, five pins 20 are provided per connecting tube 4, which pins are inserted in bores provided in the plates 3 and the connecting tubes 4. Due to the length shown in FIG. 2, the pin connection also makes it possible to position the individual plates 3. Due to the predetermined fit between the pin 20 and the bores, it is possible to position the connecting tubes 4 exactly on the outermost plate 3 In addition, a sufficient pre-fixing of the Anschlußroh¬ re 4 at the outermost plate 3 and the plates 3 with each other, so that no additional measures to secure the assembly erforder¬ Lich. In principle, however, an additional backup by means of brackets, as described above, possible, which is a pure transport security, ie the brackets are removed before soldering again, or an additional backup, which may also be soldered, can act , The pins 20 of the pin connections remain in the heat exchanger. Vorlie¬ ing are the pins 20, as well as the connecting pipes 4 and the plates 3 lot¬ plated, so that no additional measures for soldering within the assembly are required.

In the third exemplary embodiment illustrated in FIG. 3, five outwardly projecting passages 30 are formed in the outermost plate 3 per connecting tube 4, onto which radial openings are inserted, which are formed on the connecting tubes 4. Here are the passages 30 and the openings in the connecting pipes 4 in the assembled and soldered Zu¬ stood the inputs and / or outlets of the collector 2, which is formed by the plates 3. In the present case, the self-locking of the passages 30 in the openings is sufficient for the pre-assembly, in order to ensure a sufficient pre-fixing of the connection tubes 4 on the outermost plate 3, so that additional fuses can be dispensed with for cohesion of the assembly, which however does not preclude this in that additional fuses, such as, for example, clamps, are possible. According to the present exemplary embodiment, the outermost plate 3 is solder-plated, with the solder plating in the present case taking place before the passages 30 are produced. Of course, a solder plating can be done after making the passages 30. Further, if appropriate, or only the openings may be solder-plated in order to ensure a secure fixing of the connection pipes 4 to the outermost plate 3 after passing through the soldering furnace.

Of course, for example, a combination of pin connections and the passage-opening connections is possible, so that in areas in which no collector opening for introducing or discharging refrigerant vor¬ seen, the pin connections are arranged, and in the other Be¬ rich in which entry or exit points are to be provided, the fastening takes place with the aid of the passage-opening connections. The end of the connecting pipes 4, unless introduced into the collector 2 by bending the connecting pipes 4 and inserting the end into the collector 2, are closed by means of a stamped solder-plated blank (not shown), so that the inlet and outlet takes place in the radial direction of the connecting pipes 4 extending bores. The soldering of the blanks takes place in the same operation as the soldering of the entire heat exchanger 1. A corresponding arrangement is also possible in all other described embodiments.

According to the fourth embodiment shown in FIG. 4, individual solder joints 40 in meniscus-like shape, distributed along the entire length of the connection pipes 4 in the region of the plates 3 are provided. This can also be, for example, provisional cold solder joints, the closing connection takes place during the heat-soldering process in the soldering furnace. The shape of the solder joints 40 does not necessarily have to be round or nearly round, but any other shapes, for example also longitudinally extending solder joints, are possible. These solder joints 40 can also be used in conjunction with one or more other types of connection.

As an alternative to the individual solder joints 40 according to the fourth embodiment, it is also possible to provide a continuous solder seam, for example over the entire length of the connection pipes in the region of the panels.

In the fifth embodiment shown in FIG. 5, the side parts 5 are extended and provided with passages 50. The connection tubes 4 are guided through the corresponding feedthrough 50, so that due to the bore diameter there is an essentially positive positioning and prefixing of the connection tubes 4. In this case, in particular, an exact positioning of the connection pipes 4 takes place up to the corresponding heat exchanger end, which is the case with the other ones Types of connection is not possible or only with significant additional effort. In this case, the modules are formed significantly larger than in the zu¬ before described embodiments. These bushings 50 can also be combined with any other types of connection.

According to the sixth embodiment shown in FIG. 6, the outermost plate is formed with two protruding tabs 60 to which the connection tubes 4, in FIG. 6 only indicated, for example, can be attached, clamped or connected. Also in this case, an exact positioning of the connection pipes 4 to the corresponding heat exchanger end is possible.

The abovementioned exemplary embodiments can be combined with one another in any manner, so that an optimized positioning and pre-fixing of the assembly is possible. The strength of the pre-fixing can be tailored to the needs. If e.g. If final assembly takes place in the immediate vicinity and immediately thereafter, for example, a lower securing of the assembly is required than if transport from one factory to another is required.

The representation of the section through the solder joints 40 according to FIG. 4 corresponds in all described exemplary embodiments to the finished solder joint between the connection pipes 4 and the outermost plate 3. In this case, the solder of the solder-plated plate 3 collects into the wedge-like one as a result of the capillary forces Columns between the connecting pipes 4 and the outermost plate 3. Instead of or in addition to the solder-plated plate, a solder plating may be provided on the connecting pipes 4.

If solder-plated connecting tubes 4 are used, the soldering of a connecting flange can also take place in the same soldering process, which results in the production further simplified and in particular the production costs can be further reduced.

The embodiment of the heat exchanger is not limited to the previously described form with U-shaped flat tubes, but any other configurations are possible, such as, for example, a form with straight flat tubes, which open at the other end into a second collector.

LIST OF REFERENCE NUMBERS

1 heat exchanger

2 collectors

3 plate

4 connection pipe

5 side panel 10 bracket

20 pin 30 thread 40 solder joint 50 lead 60 tab

Claims

Patent claims

1. A method for producing a heat exchanger (1), in particular for a motor vehicle, characterized in that an assembly consisting of the two the refrigerant supply or dissipating An¬ end pipes (4) and at least one outermost, in particular the top plate (3) or surface of the heat exchanger (1), in which the openings belonging to the connecting pipes (4) are provided, positioned and mechanically preassembled, and after Zusammenam¬ set with the other parts to be soldered the Wärmeübertra¬ gers (1) in a joint operation is soldered.

2. The method according to claim 1, characterized in that the connection tubes (4) are positioned and preassembled during pre-assembly at least at the outermost plate (3) or surface by means of one or more clamps (10).

3. The method according to claim 2, characterized in that the Klam¬ mer (10) engages behind the collector (2).

4. The method according to any one of the preceding claims, characterized ge indicates that the connecting pipes (4) are mounted during pre-assembly by means of pins (20).

5. The method according to claim 4, characterized in that the pins (20) are provided in openings provided in the plate or plates (3) or the surface and openings provided in the connection tubes (4).

6. The method according to any one of the preceding claims, characterized ge indicates that the connecting pipes (4) have openings, wel¬ che in the pre-assembly on passages (30) in the plate (3) or Flä¬ surface are set.

7. The method according to claim 6, characterized in that the Durch¬ trains (30) remain open and serve as a refrigerant supply or discharge.

8. The method according to any one of the preceding claims, character- ized in that for pre-fixing solder joints (40) between the An¬ closing pipes (4) and the outermost plate (3) or surface are formed.

9. The method according to claim 6, characterized in that the solder joints (40) are spatially limited for prefixing.

10. The method according to any one of the preceding claims, characterized ge indicates that for prefixing at least one side part (5) is vor¬ seen, which projects beyond the connection pipes (4), wherein in the side part (5) per connection pipe (4 ) is formed a passage (50) through which the corresponding connection pipe (4) inserted and with the aid of which it is prefixed.

11. The method according to any one of the preceding claims, character- ized in that for prefixing the outermost plate (3) or surface protruding tabs (60) on which the connecting pipes (4) are pre-fixed.

12. The method according to any one of the preceding claims, character- ized in that before the pre-assembly at least the outermost plate

(3) or area in the area of the installation of the connecting pipes (4) or the

Connection pipes (4) are solder-plated in the area of the system to the outermost plate (3) or surface.

13. Heat exchanger, in particular for a motor vehicle air conditioner, wherein for the manufacture of the heat exchanger (1) an assembly be¬ standing from the two the refrigerant supply or dissipating An¬ end pipes (4) and at least the top plate (3) or surface of the Heat exchanger (1), in which the to the connecting pipes (4) belonging openings are provided, with the other verlöten¬ the parts of the heat exchanger (1) are soldered in a common Arbeits¬, wherein the connecting pipes (4), the Conduct refrigerant to the collector (2) or derived from this, with one side of the heat exchanger (1) are firmly soldered.

14. Heat exchanger according to claim 13, characterized in that the solder joint extends at least over a substantial area in which the connection pipes (4) are arranged parallel to the heat exchanger (1).

15. Heat exchanger according to claim 13 or 14, characterized in that the connection pipes (4) are solder-plated at least in the region of the flange-side ends.

16. Heat exchanger according to one of claims 13 to 15, characterized ge indicates that the outermost plate (3) or surface on which the connection pipes (4) are mounted, is solder-plated on its outside.

17. Heat exchanger according to one of claims 13 to 16, characterized ge indicates that the permissible maximum operating pressure of the Wärme¬ transformer (1) is at least 50 bar.