EP0000189A1 - Heat exchanger with water headers made of plastics and with metal water tubes, and a method for its manufacture - Google Patents

Abstract

1. A heat exchanger, in particular for motor cars with a one-piece connector chamber subdivided into an entrance chamber and a back-flow chamber and a one-piece header chamber of synthetic material, which are connected one with the other via a nest of water pipes of metal held together by air-guiding fins, the ends of the pipes being sealable fixed via a hardenable synthetic material introduced into groove-shaped recesses on the outside of the bottoms of the water chambers flaring out into the pipe apertures, characterised in that the outsides of the bottoms (8, 9) of the water chambers (1, 2) are provided with a plurality of pipe sockets (10) surrounded at a distance from the latter by annular lands (11), the hardenable synthetic material (5) being disposed in the axially open annular grooves (12) formed between the pipe sockets (10) and the annular lands (11), into which material the ends (13) of the pipes, slidable over the pipe sockets (10), can be sunk with their salient collars (14).

Description

The invention relates to heat exchangers, in particular with a one-piece connection water box divided into a flow and return space, and a one-piece deflection water box made of plastic, which are connected to one another by a tube bundle of metal water pipes held together by air-guiding fins, and the pipe ends via a into the Grooved recesses, pipe-shaped recesses, are attached to the outside of the bottoms of the water boxes, and hardened plastic material is sealed.

Heat exchangers of the type mentioned are already known from DT-OS 23 02 769 and DT-OS 23 02 770.

According to an embodiment of such a heat exchanger, one-piece connection and deflection water boxes made of plastic are used, which, however, are introduced around the pipe ends via a groove-shaped recesses widening into the pipe openings on the outer sides of the bottoms of the water boxes. hardening plastic material to be sealed sealed with these recesses must be provided in accordance with additional floor covers. These bottom covers need to be fixed in a suitable manner with respect to the water boxes, so that after the insertion of the tube ends of the tube bundle into the tube openings and the subsequent injection of hardening plastic material into the closed groove-shaped depressions, an uncontrolled escape of the plastic material is avoided.

This embodiment of a known heat exchanger thus has the disadvantage that an additional tool, material and assembly effort is required for the necessary bottom cover.

According to an alternatively proposed embodiment of such a heat exchanger, water boxes are used which are divided along a vertical, wavy cut surface containing the pipe openings. The cut surface is again provided at the height of the pipe openings with groove-shaped depressions which, after the two parts of the water box have been joined together, again form groove-shaped depressions which widen the pipe openings and into which a hardening plastic material is injected after the pipe ends have been inserted into the pipe openings.

This embodiment of a known heat exchanger avoids an increased outlay on materials, but makes an increased outlay on tools necessary for the divided water boxes. In addition, the cutting surface running over the entire circumference of the water boxes must be sealed using the hardening plastic material, which results in a high expenditure of material for hardening plastic material on the one hand and on the other hand the likelihood of possible leaks due to the large length of this sealing joint. is increased.

In addition, it is pointed out that it is in heat exchangers of the known conventional design, in which the pipe ends of a Pipe bundle of water pipes are fastened sealed in a tube sheet by means of appropriate sealing means, it is already known to apply these sealing means in the form of a hardening plastic material. Such an embodiment of a known heat exchanger can be found in DT-OS 25 09 717, the adhesives or curable plastic materials shown here having to be applied in a very complex manner to the tube sheet using a molding device.

The object of the invention is to improve a heat exchanger of the type mentioned in such a way that simple tools and little material are required for the manufacture of the one-piece water boxes made of plastic, the curable plastic material can be introduced in a simple manner and the length of the sealing joints is essential necessary minimum remains limited.

According to the invention, this object is achieved in that a heat exchanger of the type mentioned at the outset has the features set out in the patent claims. .

Characterized in that the outside of the bottoms of the water boxes are provided with a plurality of pipe sockets, which are surrounded by spaced ring webs and in the axially open ring grooves formed between the pipe and the ring webs, the curable plastic material can be introduced and the pipe ends can be plugged onto the pipe socket and can be countersunk into the plastic material with their flared collars, making it possible to manufacture the one-piece water boxes from plastic with simple tools and little material, simplifying the introduction of the curable plastic material and limiting the length of the sealing joint to the absolutely necessary minimum.

Because the inner diameter of the pipe ends is slightly larger than that Outside diameter of the pipe socket and the outside diameter of the flared collar is slightly smaller than the inside diameter of the ring webs, it is ensured that the curable plastic material already in the ring grooves before the pipe ends are fitted not only wets the pipe ends on the outside but also between the pipe socket and the inner wall of the Pipe ends rises slightly and thus anchors the pipe ends both inside against the pipe socket and outside against the ring webs. In this way, an absolutely tight and tensile fastening of the tube bundle made of water pipes to the plastic water tanks is achieved.

A product from Teroson under the name Terokal 3919 has proven to be inexpensive as a hardenable plastic material. It has good flowability and spreadability and can be cured by heating to a moderate temperature of about 140 to 200 ^° C. within a short period of time of about two minutes.

The construction of a heat exchanger 4 proposed according to the invention can of course be used accordingly for all possible known designs of heat exchangers. It is pointed out, however, that a minimum of tool, material and assembly costs are required for a certain known design of a heat exchanger due to the construction according to the invention. This is the case if, as is known per se, the heat exchanger consists of a single, one-piece connection water box made of plastic and divided into a flow and a return space and a bundle of water pipes made of metal held together by air-guiding fins, the water pipes being known per se Way starting from the flow space and returning to the return space are U-shaped. The advantages known in this type of heat exchanger are supplemented by the construction according to the invention in that the method required for producing such a heat exchanger steps are significantly simplified.

The invention is explained in more detail with reference to two embodiments of heat exchangers shown in the accompanying drawings.

• Fig. 1 eine Seitenansicht eines sehr kompakt bauenden Wärmetauschers gemäß der Erfindung;
• Fig. 2 eine Ansicht in Richtung des Pfeiles II in Fig. 1;
• Fig. 3 einen Schnitt entlang der Linie III-III in Fig. 1;
• Fig. 4 eine Ansicht in Richtung des Pfeiles IV in Fig. 3;
• Fig. 5 einen Schnitt entlang der Linie V-V in Fig. 1;
• Fig. 6 eine Ansicht in Richtung des Pfeiles VI in Fig. 5;
• Fig. 7 eine Seitenansicht eines sehr einfach bauenden Wärmetauschers gemäß der Erfindung;
• Fig. 8 eine Ansicht in Richtung des Pfeiles VIII in Fig. 7;
• Fig. 9 einen Schnitt entlang der Linie IX_-IX in Fig. 7 und
• Fig. 10 eine.Ansicht in Richtung des Pfeiles X in Fig. 9.

It shows:

• Figure 1 is a side view of a very compact heat exchanger according to the invention.
• Fig. 2 is a view in the direction of arrow II in Fig. 1;
• Fig. 3 is a section along the line III-III in Fig. 1;
• Fig. 4 is a view in the direction of arrow IV in Fig. 3;
• 5 shows a section along the line VV in Fig. 1.
• Fig. 6 is a view in the direction of arrow VI in Fig. 5;
• 7 is a side view of a very simple heat exchanger according to the invention;
• Fig. 8 is a view in the direction of arrow VIII in Fig. 7;
• Fig. 9 is a section along the line IX _- IX in Fig. 7 and
• 10 is a view in the direction of arrow X in FIG. 9.

The embodiment of a very compact heat exchanger shown in FIGS. 1 to 6 essentially consists of a connection water tank 1 made in one piece from plastic with a lower division into a supply and a return space and correspondingly shaped inlet and outlet connections and a deflecting water tank 2, which are connected to one another in a sealed manner by means of a tube bundle of water tubes 4 made of metal held together by air-guiding blades 3 made of aluminum and a hardenable plastic material 5 embedding the tube ends. A foam seal 6 encompassing the heat exchanger on its circumference is used, for example, to arrange the heat exchanger in a heater housing of a motor vehicle.

The water boxes 1 and 2, which are made in one piece from plastic, are provided on the outer sides of their flat bottoms 8 and 9 with a number of towering pipe sockets 10 corresponding to the number of water pipes 4, which are encompassed by ring webs 11 running at a distance therefrom. In the axially open annular grooves 12 formed in this way between the pipe socket 10 and the ring webs 11, which are preferably designed to overlap or run into one another, the curable plastic material 5, e.g. B. Terokal 3919 from Teroson, can be introduced via a corresponding distribution device.

In this embodiment, the water pipes 4 made of metal are designed as flat pipes onto which a large number of air guiding fins 3 made of aluminum are attached and subsequently fixed by expanding the pipes under internal pressure.

Simultaneously with the expansion of the flat water pipes 4 under internal pressure, the pipes are expanded at their pipe ends 13 by means of corresponding mandrels and provided with a collar 14 which is flared out. The widened tube ends 13 and the flared collar 1, 4 are shown in FIGS. 1 and 2 in the details highlighted in circles A and B.

The inside diameter of the widened pipe ends 13 is made somewhat larger than the outside diameter of the pipe socket 10 and the outside diameter of the flared collars 14 is made somewhat smaller than the inside diameter of the ring webs 11.

This ensures that the curable plastic material 5 introduced into the ring grooves 12 rises both on the inside and on the outside of the pipe ends 13 when the pipe ends 13 are fitted onto the pipe connections 13 and thus for a firm anchoring of the water pipes 4 in the water boxes 1 and can take care of 2.

• a) Herstellen der beiden einstückigen Wasserkästen 1 und 2 aus Kunststoff im Spritz- oder Blasverfahren;
• b) Herstellen des Rohrbündels durch Ablängen der Wasserrohre 4, Aufsetzen der Luftleitlamellen 3 und Aufweiten der Wasserrohre 4 unter Innendruck bei gleichzeitigem Aufweiten der Rohrenden 13 und Herstellen der ausgestellten Kragen 14 über entsprechende Dorne.
• c) Einbringen des aushärtbaren Kunststoffmaterials 5 in die axial offenen Ringnuten 12 der mit den Böden 8 und 9 nach oben liegenden Wasserkästen 1 und 2;
• d) Anordnen des Rohrbündels zwischen den beiden Wasserkästen 1 und 2, Kippen der beiden Wasserkästen 1 und 2 um 90 und Aufsetzen auf das Rohrbündel in der Weise, daß die aufgeweiteten Rohrenden 13 auf die Rohrstutzen 10 aufgesteckt und die ausgestellten Kragen 14 in das Kunststoffmaterial 5 eingesenkt werden;
• e) Festlegen dieser Anordnung über entsprechende Vorrichtungen und Erwärmen der Verbindungsbereiche auf eine Temperatur von etwa 140 bis 200⁰C über einen Zeitraum von ca 2 Minuten.

The production of the heat exchanger described here comprises the following process steps, some of which are known per se:

• a) Manufacture of the two one-piece water boxes 1 and 2 from plastic by spraying or blowing;
• b) Manufacture of the tube bundle by cutting the water tubes 4 to length, fitting the air guide fins 3 and widening the water tubes 4 under internal pressure while simultaneously expanding the tube ends 13 and producing the flared collar 14 using appropriate mandrels.
• c) introducing the hardenable plastic material 5 into the axially open annular grooves 12 of the water boxes 1 and 2 lying with the bottoms 8 and 9 upwards;
• d) Arranging the tube bundle between the two water boxes 1 and 2, tilting the two water boxes 1 and 2 by 90 and placing them on the tube bundle in such a way that the widened tube ends 13 are plugged onto the pipe socket 10 and the flared collar 14 into the plastic material 5 be sunk;
• e) Determining this arrangement via appropriate devices and heating the connection areas to a temperature of about 140 to 200 ⁰ C over a period of about 2 minutes.

For an explanation of these process steps, it is noted that at the required tilting of the water tanks 1 and 2 90 ⁰ no leakage of flowable Kunststoffmat is erials to worry about 5, as according to the invention the position of the adjacent vanes 3 is selected so that these the after assembly Water boxes with the tube bundle practically complete the axially open ring grooves 12. This sealing effect is sufficient for the short time until the plastic material subsequently hardens.

The embodiment of a very simple heat exchanger shown in FIGS. 7 to 10 essentially consists of the same components as the heat exchanger according to FIGS. 1 to 6, so that the same reference numerals provided with an index are used for the same or similar components.

4 The embodiment of a heat exchanger shown in FIGS. 7 to 10 has, in a manner known per se, a single, integrally made of plastic connection water box l ', which has a tube bundle of water tubes 4' made of metal held together by air guiding blades 3 'made of aluminum Pipe embedding, curable plastic material 5 'is connected in a sealed manner. The water pipes 4 'are designed in a manner known per se starting from the flow space and returning to the return space in a U-shape. The water pipes 4 'are fixed to their U-bends via an end plate 7. A foam seal 6 comprising the heat exchanger again serves to arrange the heat exchanger, for example in a heater housing of a motor vehicle.

The only one-piece water box 1 'made of plastic is similar to that described in connection with Figures 1 to 6, on the outside of its flat bottom 8' with a number of pipe ends corresponding to the number of protruding pipe sockets 10 'provided by Distance from this extending ring webs 11 'are included. In the axially open annular grooves 12 'formed in this way, which are preferably designed to merge into one another, the hardening plastic material 5, e.g. B. Terokal 3919 from Teroson can be introduced via a corresponding distribution device.

In this embodiment of the heat exchanger, the water pipes 4 'made of metal are designed as normal round pipes, in which helical swirl strips 15 can be inserted to increase the flow swirl. The large number of air guide fins 3 'made of aluminum are again plugged onto the water pipes 4' in a known manner and fixed by expanding the pipes under internal pressure.

Simultaneously with the expansion of the water pipes 4 'under internal pressure, the ends of the water pipes 4' are provided with flared collars 14 'via corresponding mandrels. The formation of the ends of the water pipes 4 'can be seen from the details shown in FIGS. 7 and 8 in circles A'.

The inner diameter of the water pipes 4 'is selected so that it is somewhat larger than the outer diameter of the pipe socket 10' and the outer diameter of the flared collar 14 'is selected such that it is somewhat smaller than the inner diameter of the ring webs 11'.

This again ensures that the water pipes 4 'are wetted both on the inside and outside with the hardenable plastic material 5' and for a tight and firm anchoring to the water box 1 'care.

• a) Herstellen des einzigen Wasserkastens l' einstückig aus Kunststoff im Spritz- oder Blasverfahren;
• b) Herstellen des Rohrbündels durch Ablängen und Biegen der Wasserrohre 4' , Aufsetzen der Luftleitlamellen 3' und Aufweiten der Rohre durch Innendruck unter gleichzeitigem Herstellen der ausgestellten Kragen 14' über entsprechende Dorne;
• c) Einbringen des aushärtbaren Kunststoffmaterials 5' in die axial offenen Ringnuten 12' des mit dem Boden nach oben liegenden Wasserkastens 1' ;
• d) Aufsetzen des Rohrbündels von oben in der Weise, daß die Rohrenden auf die Rohrstutzen 10 aufgesteckt und die ausgestellten Kragen 14' in das Kunststoffmaterial 5' eingesenkt werden;
• e) Erwärmen der Verbindungsbereiche auf eine Temperatur von etwa 140 bis 200°C über einen Zeitraum von ca zwei Minuten.

The production of this embodiment of a heat exchanger comprises the following process steps, some of which are known per se:

• a) Manufacture of the single water box l 'in one piece from plastic by spraying or blowing;
• b) Manufacture of the tube bundle by cutting and bending the water tubes 4 ', putting on the air guide fins 3' and expanding the tubes by internal pressure while simultaneously producing the flared collars 14 'using appropriate mandrels;
• c) introducing the hardenable plastic material 5 'into the axially open ring grooves 12' of the water box 1 'lying with the bottom up;
• d) placing the tube bundle from above in such a way that the tube ends are plugged onto the tube socket 10 and the flared collars 14 'are sunk into the plastic material 5';
• e) Heating the connection areas to a temperature of about 140 to 200 ° C over a period of about two minutes.

Because the pipe ends to be sealed are on one side, the material and manufacturing costs are kept to a minimum.

Claims (6)

1. Heat exchanger, in particular for motor vehicles, with a one-piece connection water tank divided into a flow and return space and a one-piece deflection water tank made of plastic, which are connected to one another by a bundle of metal water pipes held together by air-guiding fins and the pipe ends via a into the pipe openings widening, groove-shaped depressions on the outside of the bottoms of the water boxes, hardenable plastic material are sealed, characterized in that the outside of the bottoms (8 and 9) of the water boxes (1 and 2) are provided with a plurality of pipe sockets (10), which are encompassed by spaced ring webs (11) and the curable plastic material (5) can be introduced into the axially open ring grooves (12) formed between the pipe stubs (10) and the ring webs (11) and the pipe ends (13) the pipe socket (10) can be plugged on and with its flared collar (1 4) can be lowered into the plastic material (5). 2., heat exchanger according to claim 1, characterized in that the inner diameter of the pipe ends (13) is slightly larger than the outer diameter of the pipe socket (10) and the outer diameter of the flared collar (14) is slightly smaller than the inner diameter of the ring webs (11). 3. Heat exchanger according to claims 1 and 2, characterized in that the curable plastic material (5) is a material that heats up under heating to a moderate temperature of about 140 to 200 ° C within a short period of time of about two minutes. 4. Heat exchanger, in particular for motor vehicles, with a single, one-piece connection water box made of plastic, which is divided into a forward and a return space and is connected to a tube bundle of water pipes made of metal held together by air-guiding fins, in particular sealed according to a pipe material embedding the pipe ends the characteristics of claims 1 to 3, characterized in that the water pipes (4 ') are designed in a manner known in the art starting from the flow space and returning to the return space and running in a U-shape. 5. Process for producing a heat exchanger according to claims 1 to 3, characterized by the combination of the following process steps, some of which are known per se: a) Manufacture of the two one-piece water boxes (1 and 2) from plastic by spraying or blowing; b) producing the tube bundle by cutting the water tubes (4) to length, putting on the air guide fins (3) and expanding the tubes by internal pressure while simultaneously expanding the tube ends (13) and producing the flared collars (14) using appropriate mandrels; c) introducing the hardenable plastic material (5) into the axially open ring grooves (12) of the water boxes (1 and 2) lying upwards with the bottoms (8 and 9); d) arranging the tube bundle between the two water boxes (1 and 2), tilting the two water boxes (1 and 2) by 90 ^° and pushing the water boxes onto the tube bundle in such a way that the tube ends (13) onto the pipe socket (10) put on and the flared collars (14) are sunk into the plastic material (5); e) Fixing this arrangement and heating the connection areas to a temperature of about 140 to 200 ° C over a period of about two minutes. 6. A process for producing a heat exchanger according to claim 4, characterized by the combination of the following process steps, some of which are known per se: a) Manufacture of the single, one-piece water box (1 ') made of plastic by spraying or blowing; b) producing the tube bundle by cutting and bending the water tubes (4 '), fitting the air guide fins (3') and expanding the tubes by internal pressure, while at the same time producing the flared collars (14 ') using appropriate mandrels; c) introducing the hardenable plastic material (5 ') into the axially open ring grooves (12') of the water box (1 ') lying upwards with the bottom (8'); d) placing the tube bundle on the water tank (1 ') in such a way that the tube ends are attached to the tube socket (10') and the flared collars (14 ') are sunk into the plastic material (5'); e) Heating the connection areas to a temperature of about 140 to 200 ° C over a period of about two minutes.

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