EP1589311B1 - Heat exchanger, in particular for a motor vehicle - Google Patents

Abstract

An automotive air conditioner has a condenser in which heat passing through a first pipe (3) is transferred to a second adjacent pipe (14c) via a heat bridge (13). The heat bridge (13) has a saddle-shaped profile (12) with a form-fit and soldered join to the first pipe.

Description

The invention relates to a brazed heat exchanger with at least one collecting tube to which an additional part is attached, in particular according to the subject of the earlier patent application of the applicant with the file number WO 04/00560 ,

In the aforementioned earlier patent application of the applicant, a brazed heat exchanger is disclosed, which is designed in particular as a condenser of an air conditioning system for motor vehicles and having at least one refrigerant flange for connection to a refrigerant circuit and holder for suspending the capacitor. Flange and holder are additional parts, which are fixed by soldering to at least one header of the capacitor. Prior to the soldering process, all parts are positioned and fixed to maintain their predetermined position during the soldering process. For fixation various solutions are proposed in the earlier application, inter alia, a positive connection between the additional parts and the manifold or slots in the manifold, in which engage the attachment attached fixing elements. The resulting solder gaps between manifold and additional parts are indeed closed during soldering, which takes place according to the so-called Nocolok process; However, there is a risk of leaking soldering or weak point formation by a non-homogeneous Lötnahtgefüge. Since capacitors for motor vehicles are subject to a particularly strong vibration stress, the connection must in particular between holder and manifold adequately durable and stable.

By the DE 42 17 062 A It is disclosed that a clip has two holding portions which hold between each other the two end portions of the tank pressing member.

It is an object of the present invention to improve the connection technology between additional parts and manifold in a heat exchanger of the type mentioned above and to create a permanent, vibration resistant solder joint, which does not lead or to a small extent to leaks or strength problems.

This object is solved by the features of claim 1. This is achieved by a heat exchanger, in particular for a motor vehicle, with at least one collecting element formed with a cover part and a bottom part, to which at least one additional part is fastened, wherein the at least one additional part has a fork-shaped profile piece adapted to the circumference of the collecting tube, which on The circumference of the collecting tube rests and can be fixed by positive locking and frictional connection, wherein the bottom part has two longitudinally extending upper edges and the profile piece has two legs which rest with an elastic bias on the circumference of the manifold, the legs having inwardly directed paragraphs, which attacks against form the upper edges, the paragraphs are formed on the opposite sides of the legs.

According to the invention - in addition to the positive connection - a frictional connection between the additional part and the manifold provided. The additional part has a fork-shaped profile piece, which rests positively against the circumference of the collecting tube and in particular is positioned on the collecting tube before a soldering process such that a clamping fit between the fork-shaped profile piece and the circumference of the collecting tube is produced. By this clamping fit creates a frictional connection, which is a sufficient fixation of the additional part on the manifold in particular for ensures a soldering process. As a result, the advantage is achieved that the collector tube remains closed in its surface, so has no slots and possibly a soldering device, which keeps the additional part and the manifold during soldering in position is superfluous. Due to the fixation according to the invention by means of a press fit, it may also be advantageous to maintain a dense, homogeneous and permanent solder joint between the additional part and the collector pipe, which is also suitable for withstanding the vibration stresses occurring in particular in the motor vehicle.

In an advantageous embodiment of the invention, the fork-shaped profile piece on two legs, which clasp the manifold with an elastic bias. This elastic bias can be advantageously made by an undersize of the clear fork width relative to the outer diameter of the manifold, wherein the distance between the legs when pushed onto the manifold by a suitable device is increased - after pushing the legs spring back. Then the attachment sits firmly on the manifold and is fixed.

In a further advantageous embodiment of the invention, the profile piece surrounds with its legs the manifold to a circumferential angle of at least 180 °, preferably up to 210 °. As a result, the advantage of a more extensive positive engagement and preferably a locking between profile piece and manifold is achieved.

In an advantageous embodiment of the invention, the profile piece in particular on its inside a U-profile, which is composed of a bow and two adjacent straight legs. The manifold has a similar cross-sectional geometry, so that there is a surface pressure due to the elastic bias between the legs and the corresponding peripheral regions of the manifold. Thus, the advantage of a uniform soldering gap, d. H. a prerequisite for proper soldering created.

In a further advantageous embodiment of the invention, the heat exchanger is designed as a condenser of an air conditioning system for motor vehicles. The additional parts are designed as a refrigerant flange and holder, with which the capacitor is suspended in the motor vehicle at an adjacent heat exchanger, usually the coolant radiator. Advantageously Both the flange and the holder are formed as extruded parts, which each have the same extruded profile piece for embracing the manifold.

In an advantageous embodiment of the invention, the capacitor with its additional parts "in one shot", d. H. soldered in a single pass in the soldering oven, and - as already mentioned - without the use of a soldering device. The additional parts include on the one hand one or two refrigerant flanges (double flange or two individual flanges) as well as several holders, here preferably four. In addition, refrigerant connection pipes are also soldered, which lead from the refrigerant flange into the relevant manifold. The refrigerant flange serves as a fixation for the connection pipes.

Fig. 1

einen Kondensator einer Klimaanlage für Kraftfahrzeuge mit vier Haltern und einem Kältemittelflansch,

Fig. 2

den Kältemittelflansch auf einem Sammelrohr des Kondensators in perspektivischer Darstellung,

Fig. 3

einen der Halter auf einem Sammelrohr des Kondensators in perspektivischer Darstellung,

Fig. 4

den Kältemittelflansch auf dem Sammelrohr als Querschnitt,

Fig. 5

den Kältemittelflansch in einer abgewandelten Ausführungsform,

Fig. 6

den Halter auf dem Sammelrohr als Querschnitt,

Fig. 7

den Halter und das Sammelrohr vor der Montage und

Fig. 8

eine vergrößerte Darstellung des Verbindungsbereiches zwischen Halter oder Flansch und zweistückigem Sammelrohr.

An embodiment of the invention is illustrated in the drawing and will be described in more detail below. Show it

Fig. 1

a motor vehicle air conditioning condenser with four brackets and a refrigerant flange,

Fig. 2

the refrigerant flange on a manifold of the capacitor in perspective view,

Fig. 3

one of the holders on a manifold of the capacitor in a perspective view,

Fig. 4

the refrigerant flange on the manifold as a cross section,

Fig. 5

the refrigerant flange in a modified embodiment,

Fig. 6

the holder on the manifold as a cross section,

Fig. 7

the holder and the manifold before mounting and

Fig. 8

an enlarged view of the connection area between the holder or flange and two-piece manifold.

Fig. 1 shows a condenser 1 of an air conditioner, not shown, of a motor vehicle. The condenser 1 consists of a network or block 2, which is composed of flat tubes and corrugated fins, not shown. On both sides of the network 2 collecting pipes 3, 4 are arranged, which communicate with the flat tubes of the network 2. At the left in the drawing arranged collecting tube 3 a connecting flange 5 is attached, from which refrigerant connection pipes 6, 7 lead into the manifold 3. Via the refrigerant connection flange 5, the condenser 1 is connected to a not shown refrigerant circuit of the air conditioner. The condenser 1 furthermore has four holders 8, 9, 10, 11, two of which are each attached to the collecting pipes 3, 4. About the holder 8, 9, 10, 11, each having mounting holes 8a, 9a, 10a, 11a, the capacitor in the motor vehicle, in particular on an adjacent heat exchanger, such as a coolant cooler, not shown, suspended. The network 2 of the condenser 1 is flowed through by ambient air, to which the refrigerant gives off its heat of condensation.

Fig. 2 shows the refrigerant connection flange 5 in a perspective view of the manifold 3, which is only partially shown. The flange 5 is an extruded part, which has a fork-shaped profile piece 12, a web 13 and a refrigerant connection area 14 with refrigerant connection holes 14a, 14b, 14c (another hole is covered). The flange 5 is fixed by soldering on the manifold 3.

Fig. 3 shows the holder 8 (by way of example for the remaining holder, 9, 10, 11), which is also made as an extruded part of an aluminum extrusion alloy. The holder 8 consists of a fork-shaped profile piece 15, which surrounds the manifold 4 partially, from a bent web 16 and a mounting piece 17 with mounting hole 8a. The holder 8 is soldered via the profile piece 15 with the manifold 4.

Fig. 4 shows the flange 5 (according to FIG Fig. 2 ) in a cut representation (without hatching). The manifold 3 is formed in two pieces, ie, it has a lid part 3a, which is inserted into a bottom part 3b of larger diameter and forms with this lateral overlap zones 3c, 3d, via which lid 3a and bottom 3b are soldered together. The bottom 3b has passages (transverse slots) 3e, in which the pipe ends, not shown, of the flat tubes are inserted and soldered. The bottom 3b is bounded at the top by upper edges 3f, 3g, which form shoulders with the lid 3a on the outside. The fork-shaped profile piece 12 has two mutually parallel legs 12a, 12b on, which comprise the manifold 3 in the region of the overlapping zones 3c, 3d. The legs 12a, 12b are significantly extended beyond the overlapping zones 3c, 3d, so that the profile piece 12 encloses significantly more than half the circumference of the collecting tube 3. For clarity, the center point M of a circle with the diameter of the half-shell-shaped bottom 3b and four circle quadrants are shown in the manifold 3.

Fig. 5 shows a modified embodiment of a flange 18 with a modified profile piece 19, which is also fork-shaped and consists of a curved piece 19a and two adjoining, substantially parallel legs 19b, 19c. On the inside of the profile piece 19 19a to the lateral legs 19b, 19c paragraphs 20, 21 are arranged in the region of the transition of the elbow piece. In the fork-shaped profile piece 19 a dashed circle k is inscribed with a center M, wherein the circle k is approximately the circumference of the manifold 3 (see. Fig. 4 ) corresponds. The paragraphs 20, 21 are therefore arranged clearly above the center M; they serve during assembly of the profile piece 19 as a stop against the upper edges 3f, 3g of the bottom 3b of the manifold 3 (see. Fig. 4 ). Through the midpoint M is a horizontal center line m is placed in the drawing, which has a distance g with respect to the paragraphs 20, 21. In this area g, the legs 19b, 19c are aligned on the inside straight and substantially parallel to each other. Below the center line m join up to a distance e converging elbows. The free ends of the legs 19b, 19c are formed as inwardly (in the direction of the center M) facing lips 19d, 19e. They thus comprise the collection tube shown by the circle k with a circumferential angle α of significantly more than 180 °, ie about 210 °.

Fig. 6 shows the holder 8 (according to FIG Fig. 3 ) in another illustration, in a cross section through the collecting tube 4, which is formed in two pieces. The profile piece 15 for the holder 8 corresponds in principle to the profile piece 12 for the flange 5 (see. Fig. 4 ).

Fig. 7 shows the holder 8 with profile piece 15 and the two-piece manifold 4 before assembly. The manifold 4 is located in a device, not shown, and the holder 8 is placed with its profile piece 15 on the manifold 4 so that then results in a clamping or interference fit. To achieve this, the profile piece 15 has a clear width LW, and the collecting tube 4 has an outer diameter DA, wherein LW ≤ DA. The profile fork 15 thus has an undersize with respect to the outer diameter or this an excess compared to the width of the profile fork. Preferably, the difference or the excess DA - LW = 0.1 mm. For mounting the profile fork 15 is spread by a device, not shown, ie widened with respect to the inner dimension LW until a postponement of the manifold 4 is possible. After reaching the end position (stop), the legs of the profile fork are relieved by the device and thus come under pretension to rest on the overlapping areas of the manifold 4. Here, the bias depends on the selected oversize or undersize. The bias moves in the elastic region of the material of the holder 8, ie an aluminum extruded alloy - when spreading the profile fork 15 so no plastic deformation may occur. By thus achieved clamping fit of the holder is fixed to the manifold 4 for the subsequent soldering process. The solder is available as Lotplattierung available, which is applied on both sides of the bottom of the manifold 4 and on the outside of the lid. The soldering takes place by the so-called Nocolok method, ie before soldering, in this case also before the joining of the parts 8 and 4, a suitable flux is applied in a suitable form.

Fig. 8 shows a section Fig. 6 , ie an enlarged view of the profile piece 15 with manifold 4 in the assembled state. In this illustration, a circumferential angle α in the size of 210 °, including rays s1, s2, drawn, which indicates in which peripheral region (sector) the profile piece 15 includes the manifold 4. It can be seen that the legs 15a, 15b are extended over a diameter line m extending through the center M, and beyond the rays s1, s2 of the circumferential angle α. In the area of the angle beams s1, s2, the legs 15a, 15b have an increased wall thickness w2 in relation to a wall thickness w1 in the area of the center line m. The legs 15a, 15b thus form below the center line m bulge lips 15c, 15d, which engage behind the collecting tube 4 in a form-fitting manner, ie prevent or at least make it difficult to release the clamping seat. The assembly of the fork-shaped profile piece 15 takes place in the Fig. 7 described manner, ie by machine widening, subsequent joining and relieving the profile fork for the production of the clamping seat.

Claims (11)

1. Heat exchanger (1), in particular for a motor vehicle, with at least one collector tube (3, 4) made with a cover portion (3a) and a bottom portion (3b), to which at least one additional component (5, 8, 9, 10, 11) is attached, such that the said at least one additional component has a fork-shaped profiled element (12, 15, 19) that is adapted to the circumference of the collector tube, which is in contact with the circumference of the collector tube (3, 4) and can be fixed by positive interlock and force closure, the said profiled element (12, 15, 19) having two legs (12a, 12b; 15a, 15b; 19b, 19c) that rest with elastic prestressing against the circumference of the collector tube (3, 4), characterised in that the bottom portion (3b) has two upper edges (3f, 3g) that extend in the longitudinal direction and the legs of the profiled element have inward-directed extensions (10, 21) which form abutments relative to the said upper edges (3f, 3g), the said extensions being formed on opposite sides of the legs.
2. Heat exchanger according to Claim 1, characterised in that the force closure is formed by a clamping fit between the fork-shaped profiled element (12, 15, 19) and the collector tube (3, 4).
3. Heat exchanger according to Claims 1 or 2, characterised in that the profiled element (12, 15, 19) surrounds the collector tube (3, 4) around a circumferential angle α of at least 180° and preferably 200 to 210°.
4. Heat exchanger according to Claim 3, characterised in that the profiled element (12, 15, 19) forms a U-shape whose legs (12a, 12b; 15a, 15b; 19b, 19c) are substantially parallel to one another.
5. Heat exchanger according to Claim 4, characterised in that the parallel legs (15a, 15b; 19b, 19c) are extended by converging, curved sections (15c, 15d; 19d, 19e) in the form of lips that engage behind the collector tube (3, 4) with positive interlock.
6. Heat exchanger according to any of the preceding claims, characterised in that the heat exchanger is formed as a condenser (1) of an air-conditioning unit for motor vehicles, and comprises two collector tubes (3, 4).
7. Heat exchanger according to Claim 6, characterised in that the at least one additional component is formed as at least one coolant flange (5, 18).
8. Heat exchanger according to Claims 6 or 7, characterised in that the at least one additional component is formed as a holder (8, 9, 10, 11) for suspending the condenser (1).
9. Heat exchanger according to Claims 7 or 8, characterised in that the coolant connection flange (5) and/or the holder (8, 9, 10, 11) can be made as extruded components.
10. Heat exchanger according to any of Claims 6 to 9, characterised in that the condenser (1) has coolant connection pipes (6, 7) that connect the coolant flange (5) to the collector tube (3).
11. Heat exchanger according to any of Claims 6 to 10, characterised in that the condenser (1) can be soldered to the flange (5), holders (8, 9, 10, 11) and connection pipes (6, 7) in a single working operation.

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