BRPI0611998A2 - full metal heat exchanger and method for its production - Google Patents

Abstract

HEAT EXCHANGER FULLY METAL AND METHOD FOR YOUR PRODUCTION. The invention relates to an all-metal heat exchanger comprising flat tubes (1) which have two narrow sides and two broad sides (2, 3), and comprising fins (4) forming a block together with the tubes. and comprising at least one tube plate (5) and a collecting tank (6), with the edges (10) of the collecting tank (6) being connected, for example, welded to the edges (20) of the plate (5), or at least one collecting tank (6) containing the tube plate, and having projections (11) which are arranged at intervals. The invention leads to a heat exchanger that has a low installation space requirement while having comparatively good thermal properties whereby, according to the invention, the projections (11) engage the ends of the flat tubes (1) in the region of the sides. Narrows (2). The production method according to the invention therefore provides that the projections (11) are inserted into the ends of the flat tubes (1) approximately in the region of the narrow sides (2).

Description

FULL METAL AND METHOD HEAT EXCHANGER FOR YOUR PRODUCTION

TECHNICAL FIELD

The invention relates to fully metal heat exchangers, composed of flat tubes having two narrow sides and two wide sides and fins, together with which the flat tubes form a block, and wholly metal heat exchanger has or at least a base. pipe and a collection tank, with collection edge edges being connected, for example, welded to the pipe base edges, or at least one collection tank which contains the pipe base, and having projections that are arranged at intervals. The invention also relates to a production method for heat exchangers.

PREVIOUS TECHNIQUE

The heat exchanger described above is known, for example, from DE 198 19 247 A1. The same projections correspond to the openings in the pipe bases. Thereby, it is provided that the individual parts are clamped together before the welding process is carried out. Expenditure on welding aids can be considerably reduced. One known disadvantage of the heat exchanger is that the tube base still protrudes a considerable distance beyond the flat / fin tube block, which could be considered as an unnecessary spatial requirement. Moreover, the ratio of the cross sections allowed by the flat tubes to the total cross section of the heat exchanger or its tube bases is not optimal, so improvements are possible with respect to an efficient heat exchanger.

ILLUSTRATION OF THE INVENTION

The object of the invention is to provide a heat exchanger which, while providing comparatively good technical value, has a low spatial requirement.

It is possible as a side effect if a favorable production is expected, specifically also a flexible design.

The object is achieved according to the invention with respect to the completely metal heat exchanger by use of the features of claim 1. The production method according to the invention is the subject matter of claim 22. It is provided that the projections fall within narrow-sided region with flat tube ends. The projections are preferably located on the opposite longitudinal edges of the collecting tank.

Preferably it means in this case who can be provided in which projections are arranged at the longitudinal edges of the tube base, possibly associated with the disadvantage that the tube bases become more complex and some other advantages are not provided. Another possible model is to provide an additional metallic part, similar to the frame to which projections are concerned.

The production method leads to several advantages. The projections, which are inserted into the ends of the flat tubes, on the two opposite edges of the collection tank, keep flat tubes under tension during the subsequent welding process, so that the risk of the so-called "fall" of the flat tubes, with the result of inadequate welded connections. tube-based, is significantly reduced.

The invention, therefore, also permits the use of wide-sided flat tubes which may have relatively small dimensions, and consequently avoids the use, which is complex in terms of production, of a plurality of flat tube rows towards the depth of the tuboplane / fin block. . In other words, it is possible by the invention to provide heat exchangers through a significantly broader energy spectrum with significantly lower deviation expense.

In addition, the above mentioned advantages of the prior art are maintained, that is to say, specifically, the expense with welding aids is considerably reduced, since the inserted projections help to hold together the individual parts mounted on the heat exchanger.

Since flat tubes extend over the full depth of the tube base - and preferably even beyond - there is virtually no space that would not be available for the purpose of heat transfer. In other words, the cross-sectional area of the flat tubes through which the flow passes is at a favorable ratio to the entire area covered by the tube base, which in turn is approximately the same area in that respect as is covered by the entire heat exchanger. .

In addition, the proposed heat exchanger has a higher degree of process reliability during production than heat exchangers that do not have tube bases but have, instead of tube bases, enlarged flat tube ends, as they are known, for example. from DE 195 43 986 Al or from even earlier documents.

It is the case where the flat tubes project with their narrow sides beyond the width of the tube base, and the projected region, the projections engage the ends of the flat tubes, or where the width of the tube base protrudes beyond the narrow sides of the flat tubes, and in the projected region, the projections engage the ends of the flat tubes.

The first of the alternatives, as mentioned, is preferable because it better prevents the previously mentioned "fall" of the flat tubes, since in this case the embroidered collection tanks, with the projections, rest from the outside against the edge of the tube base. and because, as a result, the projections are particularly resistant to forces acting in the direction of the broad side, ie transversely with respect to the longitudinal direction of the flat tubes. In addition, the alternative appears to be more favorable with respect to producing sealed connections.

The projections in each case make contact with the narrow sides of the flat tubes from the inside, and are preferably welded there.

The tube base preferably has edges, which are curved in a manner known per se, and openings for receiving in each case a tuboplane end. According to the proposition, however, the openings extend to the curved edges.

The tube bases have curved edges on only two longitudinal sides, so that the tube bases can be made from a sheet metal strip of any desired length. Tooling costs for switching to different heat exchanger sizes as a result are considerably reduced.

The collection tank has openings on the end side. Each collection tank therefore consists of only one metal sheet with two curves, which is similarly advantageous in terms of production.

The openings at the end side of the take-off tank are closed by side portions, which are known per se, which extend across the flat tubes.

The projections are practically formed in such a manner as to assist in the insertion thereof at the ends of the flat tubes. Advantageous improvement provides the formation of projections in the form of incisors. The model makes it possible to better compensate for the length tolerances in flat tubes. Despite inevitable length tolerances, it is possible to produce sealed connections between projections and ends of flat tubes.

An all-metal heat exchanger can, in the broadest sense, be advantageously used anywhere where there is a requirement for good heat transfer efficiency at the same time as a reduced spatial requirement. The inventor envisages using heat exchangers of the type specifically referred to as cooled air coolers in motor vehicles, but without thereby excluding any other possible application, especially in the field of motor vehicles.

An all-metal heat exchanger should be a heat exchanger whose constituent parts, as specified in the claims, are composed of metal, preferably aluminum, whether or not other non-metal parts that could belong to the system are subsequently attached to the heat exchanger. heat. For example, comparatively complex fittings must be securely fastened and secured to the integral metal heat exchangers which are produced from molded metal sheets.

The projections, which are provided in a comb-like partitioning such as a strip of metal foil or the like that is attached to the wall of the take-off tank, which is seated at the ends of flat tubes, keep the flat tubes under tension during the subsequent de-molding process. , so that the risk of the "fall" mentioned above the flat pipes, with the result of improperly welded connections at the receiving openings, is also significantly reduced by the provision of the additional part. In addition, the prior art advantages are maintained, that is to say, specifically, the expense of welding aids is considerably reduced, as the strips (additional parts) have hooks at the ends that help to hold together the individual pieces of the heat exchanger by engaging the side pieces.

Collection tanks can be of a single piece or multi-piece model. A notable feature is a part which has a U-shaped cross-section, with the base section being provided with receiving openings for the pipe ends, and the two members forming the two walls of the collection tank.

If the walls are formed and joined together to form a space, then one-piece collection tanks are formed. If the walls remain substantially flat, a second part is required to form the enclosed space, resulting in two-part send-formed collection tanks. The receiving openings extend at least within the walls of the collection tank.

The projections are also practically shaped to aid in their insertion into the ends of the flat tubes.

The additional part is a chamber-like sheet of metal foil which in terms of modeling is easy to process to form the additional part. Within the context of the present invention, the term "strap" encompasses all possible physical embodiments, so that an additional part may generally be referred to in this manner. The projections on the strip or additional parts may first be projections in case the second projections are provided on the strip. The second projections are then arranged between the first projections. Second projections improve the assembly or preparation of the heat exchanger for the following welding process.

The method according to the invention for producing an all metal heat exchanger, with flat tubes and fins being placed together to form a flat tube / fin block, after which the tube bases are placed at the ends of the flat tubes and finally the collection tanks. are placed with their edges on the edges of the pipe bases, it is characterized in that the projections that are arranged in one component are inserted, in the region of the narrow sides of the flat tubes, at their ends.

The longitudinal edges of the collecting tank preferably lean against the longitudinal edges of the pipe base from the outside. The narrow sides of the flat tubes protrude beyond the longitudinal edges so that projections on the longitudinal edges of the collection tank can be inserted into the projected regions of the flat tubes. In this way, the projections keep the flat tubes in a stressed state.

BRIEF DESCRIPTION OF DRAWINGS

The invention is described below in two exemplary embodiments with reference to the accompanying drawings.

Figure 1 shows an exploded illustration of the heat exchanger according to the invention;

Figure 2 shows a front view;

Figure 3 shows a top view;

Figures 4 and 5 show perspective views of a part of a heat exchanger;

Figure 6 shows an overall perspective view of the heat exchanger;

Figure 7 shows a detail of the flat tube;

Figures 8 and 9 show an alternative mode;

Figure 10 shows an exploded illustration of the heat exchanger according to the invention.

Figures 11 and 12 show perspective views of fully produced heat exchanger. Figures 13 and 14 show perspective views of a part of the heat exchanger in an assembled situation. Figure 15 shows an advantageous model of projections.

DESCRIPTION OF EXAMPLE MODES

All the individual illustrated parts of the heat exchanger are composed of metal, preferably aluminum or aluminum alloys, which is practically coated with a solder layer. Individual parts, such as flat tubes 1, fins 4, tube bases 5, collection tanks 6, and side parts 30, are produced from metal sheets, although it is not excluded that, for example, flat tubes 1 could also be produced. produced as stretch tubes. The flat tubes 1 have a roughly rectangular cross section, however, it is possible that the narrow sides 2 are also slightly arched outwards. In the embodiment shown, the internal inserts are located on the flat tubes 1. The flat tubes 1 are then stacked with fins 4 to form a flat tube / flute block. The tube bases 5 are placed at the ends of the flat tubes 1, with the ends of the flat tubes 1 being situated in the openings 21 of the tube bases 5, where a sealed welded connection is subsequently formed. The collection tanks 6 are then placed specifically as can be seen specifically in Figure 4, with the projections 11 on the edges 10 of the take-off tanks 6 thereby being inserted into those regions of the flat tubes 1 which are formed by the right sides 2 which protrude slightly beyond the edges 20 of the tube base 5, the flat tubes 1. Preferably located on the edge of the openings 21 in the tube bases 5 are rim holes (not shown) which preferably point in the opposite direction to the take-off tank 6, so that the ends of the flat tubes do not project inwardly to ensure a small pressure loss of the medium flowing into the flat tubes 1. Plates 22 are provided between the openings21 in the tube bases 5. The plates 22 may be profiled to increase their stiffness. Finally, the side parts 30 are placed, whose side parts 30 at the same time close the openings on the end side 60 of the collection tanks 6. For this purpose, the side parts 30 have, in each case, a closing part in the shape of cup that fits into the opening 60. The side parts 30 are securely fastened, and together retain the individual heat exchanger parts by means of deformable retaining elements 61 which engage a slot 62 of the side parts. In this form, the heat exchanger is substantially prepared to perform the CAB hard desoldering process. All connections are produced in one working operation in the welding furnace.

The shape of the projections 11 is conveniently combined with the outline of the flat tubes 1 which is provided in the region of the narrow sides 2 so that insertion is facilitated and also sealed welded connections are provided. Certain production tolerances are also thus absorbed. The projection spacing 11 on the collection tanks 6 corresponds to the spacing of the flat tubes 1 in the row or with the height of the fins 4 disposed between the flat tubes 1. Here, certain tolerances must be permissible which, however, may be compensated by the convenient shape. from projections 11 (see the description of Figures 15 and 16 below).

The collection tanks 6 are of simple configuration particularly of favorable production. Only two curves are required to form the two longitudinal walls and one transverse wall. Connecting pipes70, for example, can easily be produced through modeling processes.

Particularly favorable production pipe bases 5 may also be used which are made from endless bands and need only be cut to the appropriate length because the pipe bases have no curved edges on their end sides. Consequently, no costly stretching tools are required. It is appropriate to refer to Figures 4 and 5 here. It can be seen from the figure that a shoulder 100, which is comparable to the projections 11, is provided on the edge 10 of the collecting tank 6. The shoulder 100 interacts with the corresponding cutout 101 on the edge 20 of the tube base 5 and ensures welded connections sealed there. It can also be seen from Figure 5 that the openings 21 in the tube base 5 extend to the edge 20, as indicated by the reference symbol 22. The tube bases 5, therefore, during assembly can also be pushed transversely with respect to their direction. lengthwise, or towards the broad sides 3 of the flat tube ends, over the flat tube ends. In the prior art, a movement in the longitudinal direction of the flat tubes is required for this purpose. This is referred to as "pulling" the pipe bases.

Figures 3 and 6 specifically show, in one view of one of the side parts 30, that there are no lateral protrusions of the tube bases 5 beyond the flat tube / fin block. The width of the side portions 30 corresponds approximately to the dimension of the wide sides 3 of the flat tubes 1.

It should also be noted that the heat exchanger according to the invention allows relatively easy access from the outside to connections that are crucial in welding terms. Crucial fittings of the type mentioned will be the flat tube / tube base connections. If leaks exist after the welding process is carried out, the corresponding points, as they are widely accessible, can be easily treated and eliminated later in a second welding process. In prior art gauge changers, this is often not possible, resulting in high rejection rates.

Figure 7 schematically shows an individual flat tube 1, specifically in an end view of the flat tube. Flat tubes 1 of the mentioned type are provided in desired numbers on the heat exchanger. Two projections 11 extend to each flat tube 1. Penetration depth needs to be only a few millimeters; 10-15mm is more than enough. It can be practically even smaller. It is evident that one projection 11 is situated on one edge of the collecting tank 6 and the other projection 11 is situated on the other opposite edge 10 of the collecting tank 6. The projections 11 rest squarely from the inner side against the right sides 2 of the flat tubes 1. Located on the flat tubes 1 is an internal insert 80, as is typical specifically for the coolers on which cooling air falls. In other applications, an internal insert is completely dispensed with. It is usually difficult to insert the internal inserts 80 into the flat tubes 1 such that the smallest possible deviation is generated from the narrow side region 2 to the charge air flowing therethrough, which has an adverse effect on heat transfer. As shown in Figure 7, projections 11 have a favorable effect on the reduction of disadvantageous drift, which is an added advantage of the invention. The small clearances in the corners of the flat tubes 1 are caused by the illustration. In practice they are not present or are safely enclosed in the de-molding process. The voids will also be leveled when projections 11 are inserted, since projections 11 keep both wide sides 3 under some tension in the direction of the arrow.

Figures 8 and 9 now show an alternative embodiment in which the projections 11 are arranged on the tube bases 5. In the mentioned case, the tube bases 5 must be pulled in the longitudinal direction of the tube, with the projections 11 being simultaneously inserted into the flat tube ends 1. Subsequently, the collecting tanks 6 and the side parts 30 are placed in the assembled place.

One-piece collection tanks 6 have been provided in at least the exemplary embodiment shown in Figures 10 to 14. However, it is provided in any case that the collection tanks 6 also comprise the tubing bases 5, so therefore no pipe is provided as a separate part as may be concluded from the figures. The collecting tank 6 has a base section 106 from which two curved walls 107 of the collecting tank 6 extend. The walls 107 are shaped and may be connected via a longitudinal weld seam (not shown) to form the collecting tank 6 Provided in the base section 106 are the receiving openings 21 for the flat tube ends, where the flat tube spacings 1 must correspond according to the receiving openings spacings 21. A very notable feature is that the receiving openings 21 extend to within the walls 107, i.e. they extend slightly beyond the curved edge of the walls 107 in the base section 106, as can be seen sufficiently clearly from figure 14 in reference symbol 22. In the exemplary embodiments shown, in each case a strip (additional part ) 110 is located on all walls 107 of the two collection tanks 6. On the walls 107 of a take-off tank In step 6, strips 110 have been formed with additional functions such as, for example, retaining functions 90 for accessories (not shown). It is not strictly necessary to provide strips 110 on all walls 107. It is advantageous to provide a strip 110 specifically when additional functions 70 are to be performed. In this exemplary embodiment, it would be fundamentally completely possible to dispense with such narrow strips 110 on the left collection tank walls107 which do not provide any additional function, and in order to provide the solution described above, that is, projections 11 would be arranged directly on the collection tank walls 107 6, and the pipe bases would be provided as individual pieces as shown in the figures.

An additional advantage of strip 110 can be concluded from Figure 12. It can be seen from the figure that strip 110, which is formed with the additional functions mentioned, can also contribute to the collection resistance 6. It can be seen from Figure 12 that strip 110 extends over a considerable portion of the collection tank wall 107 and is welded to wall 107.

It is possible from Figures 13 and 14 that the strip model 110 is more clearly seen with respect to the projections 11 which are arranged thereon at intervals. The projections 11 may be provided with a contour which facilitates the sliding of the projections 11 into the flat tubes 1. Between the projections 11, which are first projections 11, are in each case the second projections 12. As can be seen in each case , a second projection 12 has been arranged between the first two projections 11. The second projections 12 cause a moment of neutralization of the strip 110 which might otherwise, when the first projections 11 are located at the ends of the flat tubes, seek to project from the wall 107, the As the second projections 12 rest in each case against the fins 4 from the outside, this is prevented or at least neutralized.

It can also be seen from Figures 13 and 14 that it is advantageous to form a hook 13 at the ends of the strip 110, which hook 13 is suitable for securely holding the side portion 30 against the outer fin4. This helps to hold the heat exchanger together before welding. In addition, this also suppresses the aforementioned "projection" of the strip 110 from the wall107. In addition, it is also thus possible to dispense with the holders shown in Figure 1 at positions 61 and 62 which are intended to retain the side portions 30 in the openings on the end side 60 of the collection tank 6, which is also advantageous in terms of of production.

Figure 15 shows a detail with only one projection 11. Projections 11 are projected as incisors 111. Length tolerances on flat tubes that are in the range of +/- 1.0 mm may be more absorbed in this way. The sharp edges 112 have been formed in projections 11, whose sharp edges 112 also extend in the radii, that is to say in the transition region from the projection 11 to the collection tank wall 6or the additional part or the tube base. When the projections 11 are inserted into the ends of the flat tube, the sharp edges 112 cut off the ends of those flat tubes which are in the slightly longer tolerance range and "wrinkle" the airless ends slightly. This can be clearly seen in Figure 16 in k. The center tube is slightly longer than the two other tubes. The central tube in this place is slightly longer than the other two tubes. Acute projection approach 11 is produced, for example, by cold molding. The difference in thickness between the projections 11 and the wall of the flat tubes helps the process. The wall of the collecting tank 6, from which projections 11 are, for example, formed may be approximately 1.0-2.0 mm thick, while the wall thickness of the flat tubes may be in the range of 0.05 mm. -0.25 mm.

In general, the invention therefore provides an innovative product which, in comparison with the prior art, leaves little to be desired.

Claims (23)

1. An all-metal heat exchanger comprising: a plurality of flat tubes each having two narrow sides and two broad sides, fins which together with the flat tubes form a core, a collector and a tank of collection connected to the collector, and projections arranged at intervals, where the projection intervals correspond to the flat tube intervals, so that the projections engage the narrow sides and extend to the flat tube ends to connect the tubes to at least one between the collector and the tank. collection All-metal heat exchanger according to claim 1, characterized in that the flat tubes project with their narrow sides beyond the width of the manifold, and in the projection region, the projections engage the ends of the flat tubes. All-metal heat exchanger according to claim 1, characterized in that a manifold width extends beyond the right sides of the flat tubes and in the projected region, the projections engage the ends of the flat tubes. All-metal heat exchanger according to claim 1, characterized in that the projections contact the narrow sides of the flat tubes from the inner side and are welded in this place. All-metal heat exchanger according to claim 1, characterized in that the projections are arranged at the longitudinal edges of the collecting tank. All-metal heat exchanger according to claim 1, characterized in that the collector has edges which are curved at opposite longitudinal sides, and openings for receiving a flat tube end in a cadence, and in which the openings extend towards the ends. curved longitudinal edges. All-metal heat exchanger according to claim 1, characterized in that the collectors have curved edges only on both longitudinal sides, so that the collectors may be produced from a strip of metal foil of any desired length. All-metal heat exchanger according to claim 1, characterized in that the collection tank has open ends. All-metal heat exchanger according to claim 8, characterized in that the heat exchanger has side portions extending over the length of the flat tubes and closing the open ends of the collection tanks. All-metal heat exchanger according to claim 1, characterized in that the projections are arranged either on the collector or on a frame adjacent to the collector. All-metal heat exchanger according to claim 1, characterized in that the projections are formed in an additional portion extending along a wall of the collection tank and connected thereto. All-metal heat exchanger according to claim 1, characterized in that the manifold is formed integrally with the take-off tank, and wherein the collecting tank has two walls which are curved in the opposite direction to the manifold. All-metal heat exchanger according to claim 12, characterized in that the receiving openings extend to the walls of the collection tank. All-metal heat exchanger according to claim 11, characterized in that the additional part rests externally approximately flat against the wall of the collection tank. All-metal heat exchanger according to claim 11, characterized in that the additional part is provided with retaining functions for accessories. All-metal heat exchanger according to Claim 11, characterized in that the additional part is provided with an outline corresponding to the outline of the collection tank wall. All-metal heat exchanger according to claim 11, characterized in that the projections are first projections, with the partitioning having second projections between the first projections. All-metal heat exchanger according to claim 11, characterized in that the additional part is formed at the end with a hook or the like which is suitable for engaging a part of the heat exchanger. All-metal heat exchanger according to claim 1, characterized in that the projections are contoured to aid their insertion into the ends of the flat tubes. All-metal heat exchanger according to claim 1, characterized in that the projections are formed in the form of incisive teeth. All-metal heat exchanger according to claim 1, characterized in that the heat exchanger is a cooled air cooler. 22. Method for producing a fully metal heat exchanger, the method comprising the actions of: forming a nucleus from a plurality of flat tubes and fins; connecting manifolds to the ends of the flat tubes; connecting the edges of the collection tanks to the edges of the manifolds; and insert projections arranged in a long component of the narrow sides of the ends of the flat tubes. Method according to claim 22, characterized in that the projections extend outwardly from either the collection tank or the collector.