Heat exchanger

Abstract

A heat exchanger for an internal combustion engine may include a base tube and a flange extending at least partially around the base tube. The flange may be formed as a forged piece.

Claims

1. A heat exchanger for an internal combustion engine, comprising: a base tube; a flange extending at least partially around the base tube, wherein the flange is formed as a forged piece; and an adhesive between the flange and the base tube to provide a permanent bond between the flange and the base tube; wherein the flange has a V-shaped cross-section and is formed by a wall bent in the shape of a V to form the V-shaped cross-section with a cavity between the wall and the base tube; wherein the flange has a thread on a radially outermost section of the flange; and wherein a wall thickness t of the flange is in the range of 2 mm≤t≤3.0 mm, and a ratio of an outer diameter of the flange to the wall thickness ranges between 37.3:1 and 56:1.

2. The heat exchanger as claimed in claim 1, wherein the heat exchanger is formed as an exhaust gas heat exchanger.

3. The heat exchanger as claimed in claim 1, wherein the flange is formed as a closed ring.

4. The heat exchanger as claimed in claim 1, wherein the flange has at least one contact section with which the flange rests flatly on the base tube.

5. The heat exchanger as claimed in claim 1, wherein the base tube has two connecting pieces via which a fluid is led into an interspace delimited by tubes of the base tube and the base tube.

6. The heat exchanger as claimed in claim 1, wherein a wall thickness t of the flange is 2.3 mm.

7. A motor vehicle comprising at least one heat exchanger having: a base tube; a flange extending at least partially around the base tube, wherein the flange is formed as a forged piece; and an adhesive between the flange and the base tube to provide a permanent bond between the flange and the base tube; wherein the flange is formed by a wall having a contact section and a V-shaped section, the contact section resting flatly against the base tube, and the contact section and the V-shaped section having a same thickness; wherein the V-shaped section has a thread; and wherein a wall thickness t of the flange is in the range of 2 mm≤t≤3.0 mm, and a ratio of an outer diameter of the flange to the wall thickness ranges between 37.3:1 and 56:1.

8. The heat exchanger as claimed in claim 2, wherein the flange is formed as a closed ring.

9. The heat exchanger as claimed in claim 2, wherein the flange has a thread.

10. The heat exchanger as claimed in claim 2, wherein a wall thickness t of the flange is in the range of 2 mm≤t≤3.0 mm.

11. The heat exchanger as claimed in claim 10, wherein the flange is formed as a closed ring.

12. The heat exchanger as claimed in claim 10, wherein the flange has a thread.

13. A heat exchanger for an internal combustion engine, comprising: a base tube having tubes in which a first fluid is flowable, and two connecting pieces via which a second fluid is led into an interspace delimited by the tubes and the base tube; and a flange extending at least partially around the base tube, the flange being formed from a wall bent to have at least one contact section with which the flange rests flatly on the base tube, and a V-shaped section defining a cavity between the wall and the base tube, the flange being formed as a forged piece and adhesively bonded to the base tube; wherein the at least one contact section and the V-shaped section have a same thickness; wherein the flange has a thread on a radially outermost section of the V-shaped section; and wherein a wall thickness t of the flange is in the range of 2 mm≤t≤3.0 mm, and a ratio of an outer diameter of the flange to the wall thickness ranges between 37.3:1 and 56:1.

14. The heat exchanger as claimed in claim 1, wherein the wall has a uniform thickness.

15. The heat exchanger as claimed in claim 5, wherein the two connecting pieces are on the same side of the flange.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the figures, in each case schematically,

(2) FIG. 1 shows a view of a heat exchanger according to the invention,

(3) FIG. 2 shows a sectional illustration through the heat exchanger according to the invention.

DETAILED DESCRIPTION

(4) According to FIGS. 1 and 2, a heat exchanger 1 according to the invention, which can be formed as an exhaust gas heat exchanger, for example, has a base tube 2, in which tubes 3 carrying a first fluid (cf. FIG. 2) are arranged in the manner of a tube bundle. This tube bundle is held at the ends in opposite tube sheets 4. According to FIG. 2, here the tubes 3 and the tube sheets 4 are sketched only partly. Extending at least partially around the base tube 2, here even running completely around, there is arranged a flange 5 which, according to the invention, is formed as a forged piece. Forming the flange 5 as a forged piece offers the great advantage that complicated mechanical re-working, as was necessary in the previous formation of the flange 5 as a cast part, is now no longer necessary. Furthermore, such a flange 5 formed as a forged piece is considerably lighter than a flange formed as a cast part, which means that weight advantages can be realized which bring advantages with regard to fuel consumption and exhaust gas emission, in particular when the heat exchanger 1 according to the invention is used in a motor vehicle.

(5) If FIG. 2 in particular is considered, it can be seen that the flange 5 has a V-shaped cross section and in addition has a contact section 6, with which it rests flatly on the base tube 2. Via this contact section or in general, the flange 5 can be welded, brazed, pressed or adhesively bonded to the base tube 2.

(6) In addition, the base tube 2 has two connecting pieces 7 via which a second fluid can be led into the interspace 9 remaining between the tubes 3 and the base tube 2.

(7) Of course, it is also conceivable for the flange 5 to have a thread 8, via which, for example, a further component can be screwed to the flange 5. The thread 8 can likewise be forged or else subsequently turned into the flange 5.

(8) Advantageously, a wall thickness t of the flange 5 lies between 2 mm≤t≤3.0 mm, in particular at t=2.3 mm. In particular in the case of a flange 5 with a flange diameter d.sub.F of 112 mm, the aforesaid wall thicknesses t are particularly advantageous. In this way, the flange 5 can be formed with a considerably lower wall thickness than would be possible in the case of a flange made of cast material. The weight can also be reduced as a result of the lower wall thickness t.

(9) Above all, however, no mechanical re-working is required, which means that costs can likewise be spared. As a result of a lack of contaminants (slag, inclusions), as always have to be tolerated in the case of cast components, and as a result of a more homogenous distribution of the alloy components, improved mechanical characteristics can be achieved in forged flanges 5. As a result of the microstructure being more homogenous as compared with cast components (small-grained in forged components and coarse-grained in cast components), forged pieces also exhibit improved corrosion characteristics and increased fatigue strength. In addition, in the case of flanges 5 formed as forged pieces, the fatigue characteristics can be influenced advantageously, since the grains in the structure of the flange 5 are aligned after the forging. In the case of cast components, on the other hand, the grain growth following solidification is preferentially oriented in the transverse direction, since the solidification begins at the surface and continues inward as a result of the growth of coarse column-like grains, which is particularly disadvantageous from fatigue points of view.

(10) As a result of the implementation of the flange 5 as a forged piece, the mechanical machining which is required in the case of a flange formed as a cast part can be dispensed with and, as a result, costs can be saved. Furthermore, thinner wall thicknesses can be realized. Moreover, as a result of the reduced use of material, weight and costs can be saved.