EP0566899B1 - Heat exchanger, particularly evaporator - Google Patents

Description

The invention relates to a heat exchanger, in particular an evaporator for an air conditioning system, with a distribution device which has an inlet and leads from this inlet to tubes of a heat exchanger block, individual channels formed by means of a profile body and walls of the distribution device.

In a known type (DE-A 33 11 575) the profile body is inserted into a round tube. In order to fix the profile body in its position and to obtain sufficient tightness, it must be pressed in.

A heat exchanger to be used in particular as an evaporator is also known (DE-A 39 09 164), which is formed from a system of U-shaped tubes, the ends of which are held in a base. The U-shaped pipes are combined into groups by means of elbows, each of which has an inlet and an outlet. The entrances are supplied with the medium to be evaporated via individual feed pipes. The outlets of the groups are assigned a common collecting device which is formed from two profiled plates which form connecting channels for a plurality of outlets.

A heat exchanger to be used in particular as a condenser is also known (EP-A 0 379 701), in which the connection boxes in which a multiplicity of pipes begin or end are made from two sheet metal profiles.

The invention has for its object to provide a heat exchanger of the type mentioned, which has a distribution device, which consists of easy to manufacture parts and which is easy and in particular in large quantities to assemble with the least possible effort and also by means of machines .

This object is achieved in that the distribution device is assembled from two sealingly interconnected sheet metal profiles, which are provided with connections for the tubes and for an inlet pipe forming embossments and which accommodate the profile body between them and together with this profile body that of the connection for the Form inlet pipe to the connections for the pipes leading individual channels, and that at least one of the sheet metal profiles is provided with a protrusion securing the profile body in a predetermined position against rotation.

Such sheet metal profiles can be produced easily and above all with a high degree of dimensional and tolerance accuracy and then just as easily joined together. The connection is made by soldering or gluing, in which case the tubes of the heat exchanger block and an inlet tube are also inserted and attached in a sealing manner, i.e. for example, complete soldering. Due to the projection securing the profile body in a predetermined position, the predetermined position of the profile body is secured during assembly, so that it must be installed in its correct installation position.

In a further embodiment of the invention, it is provided that the sheet metal profiles have a plate-like or strip-like basic shape and are provided with half-shell-shaped impressions are, between which in the plane of the row of tubes are left connecting surfaces, in the area of which the sheet metal profiles are sealed together. This results in large connecting surfaces, which on the one hand ensure a secure seal, while on the other hand they also bring about a high level of strength with which the sheet metal profiles are held together.

In a further embodiment of the invention it is provided that the impressions serving as connections for the tubes of the heat exchanger block connect to the central impression with a constriction adapted to the inside diameter of the tubes. On the one hand, this gives a streamlined cross section, while on the other hand the constriction forms a stop against which the tubes of the heat exchanger block are placed when they are inserted, so that their position is exactly determined.

In a further embodiment of the invention, it is provided that the sheet metal profiles are provided with at least two index holes that are aligned with one another when they are joined together. These index holes, which can be punched out in a simple manner during the production of the sheet metal profiles, ensure that the assembly and subsequent connection between the two sheet metal profiles are accurate. They can be attached in a simple manner during the stamping or pressing of the sheet metal profiles, so that no significant additional effort is required.

In another embodiment of the invention it is provided that one of the two sheet profiles is provided with passages serving as connections for the tubes of the heat exchanger block, and that the other sheet profile serves as a cover for the sheet profile provided with the passages. In this way, a distribution device can also be produced in an inexpensive manner, which enables easy assembly.

Fig. 1

zeigt eine Ansicht auf eine Verteileinrichtung für einen Wärmetauscher, deren wesentlicher Bestandteil zwei zusammengefügte Blechprofile sind,

Fig. 2

eine Seitenansicht eines der Blechprofile mit einem eingelegten Profilkörper, einem eingelegten Zulaufrohr und eingelegten Rohren eines Wärmetauscherblockes,

Fig. 3

eine Teilansicht des Endbereiches eines der Blechprofile in größerem Maßstab,

Fig. 4

einen Schnitt entlang der Linie IV-IV der Fig. 2 einer (vollständigen) Verteileinrichtung in größerem Maßstab und

Fig. 5

einen Schnitt durch eine weitere Ausführungsform einer Verteileinrichtung für einen Wärmetauscher.

Further features and advantages of the invention result from the following description of the embodiments shown in the drawing and the subclaims.

Fig. 1

shows a view of a distribution device for a heat exchanger, the essential component of which are two joined sheet metal profiles,

Fig. 2

1 shows a side view of one of the sheet metal profiles with an inserted profile body, an inserted inlet pipe and inserted pipes of a heat exchanger block,

Fig. 3

a partial view of the end region of one of the sheet metal profiles on a larger scale,

Fig. 4

a section along the line IV-IV of Fig. 2 of a (complete) distribution device on a larger scale and

Fig. 5

a section through a further embodiment of a distribution device for a heat exchanger.

1 to 4, which is intended in particular for an evaporator of a vehicle air conditioning system, contains two sheet metal profiles (10, 11) which are produced from an aluminum alloy and are formed by pressing. The starting material is a sheet metal plate of approximately 1.0 mm thickness, from which a strip-shaped object is punched out, which is provided with several embossments, which are described below.

The sheet metal profiles (10, 11) have a central, half-shell-shaped indentation (12) which forms a channel which runs in the plane of the ends of a row of tubes (13) which belong to a heat exchanger block. The channel (12) is closed at its end (14). At the beginning there is also a half-shell-shaped impression (15) of a smaller radius, which is a nozzle. The indentation (15) is preceded by a further indentation (16) which ends in an indentation (17) which is enlarged in radius and serves as a connection into which an inlet pipe (18) is inserted. Conical transitions are formed between the impressions (12, 15 and 16).

As can be seen from FIGS. 1 and 2, there are very large structural freedoms both with regard to the course of the channel formed by the impressions (16) and with regard to the spatial arrangement. In the embodiment, the channel has a Z-shaped course in the plane of FIG. 1 and a U-shaped course in the plane of FIG. 2, so that the inlet pipe (18) is laterally and vertically offset from the row of pipes is coming. However, any modifications with regard to the position of the inlet pipe (18) are possible. In particular, it is possible to solder the Bleckprofile (10, 11) in the flat state and then to bend them.

Depending on the number of tubes (13), several transverse, also half-shell-shaped impressions (19) branch off from the central impression (12) and serve as connections for the tubes. These impressions (19) have a stepped shape, i.e. they begin at the central indentation (12) with a smaller radius, which is adapted to the inner diameter of the tubes (13), and then pass into an outer section with a larger radius, which is adapted to the outer diameter of the tubes (13). The step between the sections of the impressions (19) serves as a stop for the tubes (13). These pipes (13) are provided in a manner not shown with transverse ribs, as is common in such heat exchangers. The tubes (13) are part of a preassembled tube / fin package which are connected to one another during the complete soldering.

A profile body (20) is inserted into the central impressions (12) and has an approximately star-shaped cross section.

The star-shaped webs of the profile body (20) run in the axial direction helically or helically so that, together with the inner wall of the indentations (12), they divide the channel present in this area into individual channels, each of which runs helically to one of the indentations (19) Each tube (13) of the heat exchanger block is thus assigned a single channel which begins at the conically widened nozzle formed by the impressions (15), into the area of which the profile body (20) protrudes with a beginning beginning at a point. The length of the profile body (20) is adapted to the length of the impressions (12) so that it is fixed in the axial direction. The sheet metal profile (10) is provided in the region of the indentation (12) with an embossed nose (21) which engages between two webs of the profile body and secures it against rotation.

All impressions (12, 15, 16, 17 and 19) are each delimited by large-area, flat connecting surfaces with which the two sheet metal profiles (10, 11) are connected in a tightly sealed manner opposite one another. This connection takes place after inserting the ends of the tubes (13), the inlet tube (18) and the profile body into the relevant embossments. In a first embodiment, these connecting surfaces are connected to one another, as are the tubes (13) with the impressions (19), the inlet pipe with the impressions (17) and also the profile body (20) with the impressions (12) by means of soldering. For this purpose, it is provided that the inside of the profiled sheets (10, 11) are provided with a solder plating. Solder plating can also be provided on the tubes (13) and the inlet tube (18). In this embodiment, a metallic profile body (20), for example made of an extruded aluminum profile, is then expediently provided.

In another embodiment, the sheet metal profiles (10, 11) are connected to one another and to the tubes (13) and the inlet tube (18) by means of an adhesive. The profile body (20) can also be produced as a molded plastic part. In all cases, the large-area connection surfaces offer high strength and also very good tightness.

While it is provided in the embodiment according to FIGS. 1 to 4 that the parting line between the two sheet metal profiles (10, 11) runs in the common plane of the tubes (13), it is provided in the embodiment according to FIG. 5 that the parting line between a sheet profile (22) and a further sheet profile (23) transverse to this common plane of the tubes of the heat exchanger block. In this exemplary embodiment, the sheet-metal profile which has a half-shell-shaped central indentation (12 ') for the profile body (20) is provided with passages (24) into which the ends of the tubes (13) of a heat exchanger block are inserted.

As shown in Fig. 5, the ends of the tubes (13) are inserted against the ribs of the profile body (20). The sheet metal profile (22) is provided on its edges with a stepped bend (25) in which the sheet metal profile (23) serving only as a lid is inserted with its edges. In this case too, the sheet metal profiles (22, 23) are soldered to the tubes (13), the profile body (20) and an inlet pipe (not shown) in a sealing manner.

As has already been mentioned, the tubes (13) with fins (not shown) form a heat exchanger block, a so-called tube fin block. The ends of the tubes (13), not shown, are received by a collecting device, which can also be formed from two sheet metal profiles in accordance with the distribution device. In most cases, this collection device will have the same structure as the distribution device. In some cases, however, it will be possible to simplify the collecting device somewhat and, for example, to dispense with the profile body (20).

As can be seen in Fig. 2, the sheet metal profiles (10, 11) are provided in the area of their connecting surfaces with a plurality of index holes (26), which are expediently stamped in when the sheet metal profiles (10, 11) are formed. These index holes (26) allow the two sheet metal profiles (10, 11) to be assembled exactly during assembly, for which purpose the index holes (26) of the two sheet metal profiles are brought into alignment one above the other. This can be done, for example, using the spikes of an assembly device.

Claims (9)

1. Heat-exchanger, in particular an evaporator for an air-conditioning unit, with a distributor device comprising an inlet and individual channels formed by a shaped body (20) and the walls of the distributor device and leading from the said inlet to the tubes of a heat-exchanger block, characterized in that the distributor device is made by joining together in a leakproof way two shaped sheet components (10, 11; 22, 23) which are provided with concavities (19, 17, 24) that form connections for tubes (13) and for an inlet pipe (18) and which hold the shaped body (20) between them and, together with the said shaped body, form individual channels leading from the connection for the inlet pipe (18) to the connections for the tubes (13), and at least one of the shaped sheets is provided with a projection (21) which secures the shaped body in a predetermined position against rotation.
2. Heat-exchanger according to Claim 1, characterized in that the shaped sheet components (10, 11) are essentially of plate or strip shape and are provided with press-formed concavities (12, 15, 16, 17, 19) of semicircular section between which contact surfaces are left in the plane of the tubes, whereby the shaped sheets are joined in a leakproof way.
3. Heat-exchanger according to Claim 2, characterized in that the concavities (19) serving as connections for the tubes (13) of the heat-exchanger block have a constriction ending at a central concavity (12) which holds the shaped body (20), the said constriction matching the internal diameter of the tubes (13).
4. Heat-exchanger according to any of Claims 1 to 3, characterized in that a nozzle-shaped constriction (15) is formed in a channel (16) between the connection for the inlet pipe (18) and the shaped body (20).
5. Heat-exchanger according to Claim 4, characterized in that the shaped body (20) is pointed at one end, and the said point projects into the nozzle-shaped constriction (15).
6. Heat-exchanger according to any of Claims 1 to 5, characterized in that the shaped sheets (10, 11) are provided with at least two locating holes (26) that must be brought into alignment when the sheets are joined together.
7. Heat-exchanger according to Claim 1, characterized in that one of the two shaped sheet components (22, 23) is provided with passages (24) serving as connections for the tubes (13) of the heat-exchanger block, and the other shaped sheet component (23) serves as a cover for the one comprising the said passages.
8. Heat-exchanger according to any of Claims 1 to 7, characterized in that the shaped sheet components (10, 11; 22, 23) are made from an aluminium alloy.
9. Heat-exchanger according to any of Claims 1 to 8, characterised in that the shaped sheet components (10, 11; 22, 23) are braze-coated on their inside.

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