EP1842023B1 - Heat exchanger, in particular a charge intercooler or coolant cooler for motor vehicles - Google Patents

Abstract

The invention relates to a heat exchanger ( 1 ), in particular a charge intercooler or coolant cooler for motor vehicles, which comprises a soldered block which is made of pipes ( 4 ), ribs and at least one pipe base ( 2 ), in addition to at least one plastic box ( 3 ) which has a wall ( 3 a) which extends in the cross-section and which is approximately U shaped and a surrounding flange ( 3 b). The box is mechanically connected to the pipe base over flange ( 3 b). According to the disclosure, reinforcing ribs are arranged on the inner side of the plastic box ( 3 ) in a transition area between the flange ( 3 b) and the wall ( 3 a).

Description

The invention relates to a heat exchanger, in particular a charge air cooler or coolant radiator for motor vehicles according to the preamble of claim 1.

Known heat exchangers, especially for motor vehicles, often have a brazed block consisting of pipes, ribs and tube sheets, on which collecting boxes are placed from plastic. The connection between the plastic boxes and the tubesheets is designed as a clamp or flare connection, wherein a seal is inserted between a flange of the plastic box and the tubesheet and clamped by the box / floor connection. Thus, the plastic boxes are firmly and tightly connected to the metallic tube sheet.

Such a box / floor connection was by the DE-B 28 52 408 the Applicant known, wherein deformable edge regions of a tube sheet via a flange of a water box grip and thus produce a positive connection. The plastic boxes tend at an increased internal pressure to deformations and increased stresses, in particular above the clamping area, which can also lead to leakage of the box / floor connection.

In the DE-A 38 41 470 The Applicant has therefore proposed a modified flange portion for a so-called Wellenschlitzbördelung, wherein the wall of the box above the flange is wave-shaped and thus leads to a stiffening of the longitudinal wall.

Especially with intercoolers, as z. B. by the DE-A 198 57 435 have become known, higher internal pressures occur within the plastic box, and with increasing tendency in future developments, so that conventional plastic boxes can not withstand this stress. Rather, deformations can occur which result in increased stresses and cracking.

It is an object of the present invention to improve a heat exchanger of the type mentioned, in particular its plastic box with respect to the internal pressure resistance, without significantly increasing the weight of the heat exchanger.

There are also known heat exchangers whose box have stiffening ribs. For example, the shows DE 23 53 405 A1 a heat exchanger according to the preamble of claim 1, but which can be further optimized.

This object is solved by the features of patent claim 1. According to the invention it is provided that on the inside of the plastic box above the flange, d. H. a plurality of stiffening ribs is provided in the transition region between the flange and the box wall, the inner edges are aligned with the inner wall of the box. Thereby, the advantage is achieved that the plastic box stiffened at elevated internal pressure in the critical area and is resistant to deformation resistant. Thus, voltage peaks are reduced to a permissible value in this area of the box above the box / floor connections. In particular, a plastic box stiffened according to the invention can be used as a charge air cooler.

In an advantageous embodiment of the invention, the plastic box has a U-shaped cross-sectional profile, which merges via a shoulder in the peripheral flange. The stiffening ribs are arranged on the inside in the corner region of the approximately obtuse-angled shoulder, the inner edge of which is preferably aligned with the U-profile of the inner wall of the box. Thereby, the advantage is achieved that the stiffening ribs are arranged in an area where they pass through the box Medium, so coolant or charge air oppose no significant flow resistance, ie the stiffening ribs according to the invention cause no increased pressure drop in the plastic box. They also cause no significant increase in weight, since the wall thickness of the box itself is not increased and the ribs are formed relatively thin-walled. They thus increase relatively little weight and pressure loss free the moment of resistance in the critical region of the box, which is particularly burdened by bending due to increased internal pressure at this point.

In an advantageous embodiment of the invention, the heat exchanger has a block with a single or multi-row flat tube system, wherein the ends of the flat tubes are received in passages of the tube sheet. The stiffening ribs are spaced apart from one another which corresponds to the pipe pitch, i. the distance of the tubes, or an outer rib division, i. corresponds to the distance of ribs on the outside of the box. The stiffening ribs can be arranged either at the level of the tubes or between them. This results in a uniform stiffening of the box longitudinal wall, which is adapted to the internal pressure load.

In a further advantageous embodiment of the invention, the transition region between the flange and the box wall in the longitudinal direction of the box is wave-shaped - as by the aforementioned DE-A 38 41 470 the applicant is already known. Advantageously, the stiffening ribs are arranged in the region of this wave profile, either in the region of indentations (wave troughs) or bulges (wave crests) on the inside of the box. As a result, the advantage of further stiffening is achieved without significant increase in the pressure drop in the box.

In a further advantageous embodiment of the invention, the ribbed surfaces which protrude into the interior of the plastic box, are arranged parallel to the Entformungsrichtung of the box. The rib profiles can thus be incorporated into the core of the box, after the injection of the box in Entformungsrichtung and without the use of additional Sliders pulled, ie can be removed from the mold. As a result, the advantage of lower manufacturing costs is achieved because no significant increase in the price of the pointed tool is carried out by the inventive design and arrangement of the stiffening ribs.

Fig. 1

einen Ausschnitt eines erfindungsgemäßen Wärmeübertragers mit Verbindung zwischen Rohrboden und Kunststoffkasten,

Fig. 2

eine Einzelheit X aus Fig. 1 mit erfindungsgemäßen Versteifungs- rippen,

Fig. 3

eine perspektivische Darstellung des Kunststoffkastens mit einer ersten Anordnung von Versteifungsrippen,

Fig. 4

den Kunststoffkasten mit einer zweiten Anordnung von Versteifungs- rippen,

Fig. 5

einen Ausschnitt der Längswand des Kunststoffkastens (erste Anordnung),

Fig. 6

einen Schnitt entlang der Linie VI-VI in Fig. 5,

Fig. 7

einen Ausschnitt der Längswand des Kunststoffkastens (zweite Anordnung) und

Fig. 8

einen Schnitt entlang der Linie VIII-VIII in Fig. 7.

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

Fig. 1

a detail of a heat exchanger according to the invention with connection between tube sheet and plastic box,

Fig. 2

a detail X out Fig. 1 with stiffening ribs according to the invention,

Fig. 3

a perspective view of the plastic box with a first arrangement of stiffening ribs,

Fig. 4

the plastic box with a second arrangement of stiffening ribs,

Fig. 5

a section of the longitudinal wall of the plastic box (first arrangement),

Fig. 6

a section along the line VI-VI in Fig. 5 .

Fig. 7

a section of the longitudinal wall of the plastic box (second arrangement) and

Fig. 8

a section along the line VIII-VIII in Fig. 7 ,

Fig. 1 shows a section of a heat exchanger 1 according to the invention, which has a tube sheet 2, a plastic box 3 and flat tubes 4, which are received in passages 2a of the tube sheet 2. The tube sheet 2 has - as known from the prior art - an outer circumferential groove 2b, to which an outer edge region 2c connects. The plastic box 3 has a not fully illustrated U-profile with a wall 3a, which merges into a flange 3b with greater wall thickness. The flange 3b and a seal, not shown, are inserted into the channel 2b of the tube sheet 2 and clamped by the deformable edge portion 2c by a not shown crimping or clamping connection against the tube sheet 2. Such box / floor connections are known from the above Technology, z. B. from the DE-A 38 41 470 known. The flat tubes 4 are soldered to a block with not shown corrugated fins and the passages of the tube sheets, of which only the tube sheet 2 is partially visible. On the soldered block are the plastic boxes, of which in turn only the box 3 is partially shown, put on and braced.

Fig. 2 shows a detail X from Fig. 1 ie, a transition region 5 between the wall 3a of the plastic box 3 and the flange 3b, wherein the transition 5 is formed as a shoulder and the inner edge 3d of the wall 3a is offset inwardly by about a wall thickness relative to the inner edge 3e of the flange 3b. By the paragraph 5 receives the plastic box 3 so a so-called collection. In the area of paragraph 5 3 stiffening ribs 6 are arranged on the inside of the box, whose inner edges 6a are aligned with the inner edge of the box wall 3 a 3 a. The stiffening ribs 6 thus fill the obtuse angle of the shoulder 5 and extend into the region of the flange 3b. The arrangement of the stiffening ribs 6, a stiffening of the box is achieved in the transition region 5, ie in a region which is subject to an increased load due to the internal pressure. The heat exchanger 1 is preferably designed as a charge air cooler and therefore with compressed charge air of about 2 bar (with increasing pressures is expected in the future) acted on, which leads to a critical stress of the plastic box in the area above the flange - but the invention act Stiffening ribs against, without increasing the wall thickness, ie without a significant weight gain of the box. 3

Fig. 3 shows a perspective view of the corner region of a plastic box 7 with stiffening ribs 8 according to the invention on the inside of a longitudinal wall 7b. The box 7 has a rectangular, circumferential flange 7a, not shown completely, above which a wavy formed transition region 9 is arranged, as he from the above-mentioned DE-A 38 41 470 the applicant is aware - the latter disclosure is therefore incorporated in full in the disclosure of this application. The connection, not shown, between tube sheet and box 7 corresponds to the known design in this Offenlegungsschrift. Due to the wave-shaped design of the transition region 9, indentations 10 and bulges 11 result on the inside of the box 7. The stiffening ribs 8 are arranged above the indentations 10 in this first embodiment.

Fig. 4 shows a second embodiment of the arrangement of stiffening ribs 12 in a plastic box 13, which also has a wavy transition region 9, corresponding to the previously described transition region 9 in Fig. 3 , Therefore, recesses 10 and bulges 11 are also formed on the inside of the box 13, which form the wave-shaped wall profile. The stiffening ribs 12 are arranged here in the region of the bulges 11, ie on the raised areas of the box inner wall and in each case between two indentations 10. In this case, the length of the stiffening ribs 12 is greater than in the embodiment according to FIG Fig. 3 , In both embodiments, ie the stiffening ribs 8 and the stiffening ribs 11 whose rib surfaces (corresponding to the surface 6 in FIG Fig. 2 ) are each formed parallel to each other, said surfaces are approximately perpendicular to an imaginary tube bottom plane or a plane defined by the circumferential flange 7a plane. This means that an unillustrated core can be pulled in the production of the plastic boxes 3, 7, 13 in one direction, the so-called Entformungsrichtung. The arrangement and design of the stiffening ribs 6, 8, 12 thus requires no additional slide and can also be made possible by changes to an existing tool.

Fig. 5 shows a different view of the embodiment according to Fig. 3 ie, a view of a section of the longitudinal wall 7b of the plastic box 7 with flange 7a. Above the flange 7a of the wavy transition region 9 is indicated. The longitudinal wall 7b is stiffened on its outer side by a transverse ribbing 7c.

Fig. 6 shows a section along the line VI-VI in Fig. 5 ie by the flange 7a. On the inside of the longitudinal wall 7b are in the region of the wave profile 9 (see. Fig. 5 ) Indentations 10 and bulges 11, so wave peaks and wave troughs formed. In each case between two bulges 11 are arranged vertically projecting into the interior stiffening ribs 8, and - as in Fig. 3 recognizable - above the indentations 10. The stiffening ribs 8 extend up to a line 7d inwardly, which forms the inner contour of the longitudinal wall 7b. In this respect, the stiffening ribs 8 are aligned with the inner wall 7d, whereby a low pressure drop is ensured. The distance between the stiffening ribs 10 otherwise corresponds to the distance of the flat tubes, not shown. The ribs 8 also extend perpendicular to the plane of the drawing and are thus easily demountable with the main core of the box.

Fig. 7 shows a view of a section of the side wall 13a (see. Fig. 4 ) of the box 13 with wave profile 9.

Fig. 8 shows a section along the line VIII-VIII in Fig. 7 Through the flange of the box 13. Through the wave profile 9 arise on the inside indentations 10 and protrusions 11, on which the stiffening ribs 12 (see. Fig. 4 ) are arranged. The vertically inwardly projecting stiffening ribs 12 extend to an edge 13b, which corresponds to the inner edge of the longitudinal wall 13a (perpendicular to the plane of the drawing). Thus, the stiffening ribs 12 protrude no further than the longitudinal wall 13a itself in the interior of the box and thus also cause no increased pressure drop for the flow medium, eg. B. charge air or coolant.

Claims (9)

1. Heat exchanger, in particular intercooler or coolant cooler for motor vehicles, comprising an in particular soldered block consisting of tubes (4), fins and at least one tube sheet (2), and further comprising at least one case (3) made in particular of plastic or metal, which has a wall (3a) with an in particular approximately U-shaped cross-section and a continuous flange (3b) and which is mechanically joined to the tube sheet (2) via the flange (3b), wherein reinforcing ribs (6) are provided on the inside of the case (3), in particular in a transitional region (5) between the flange (3b) and the wall (3a), characterised in that the reinforcing ribs (6) have internal edges (6a) arranged in alignment with the internal wall (3d).
2. Heat exchanger according to claim 2, characterised in that the transitional region has an in particular continuous offset (5) which is directed inwards.
3. Heat exchanger according to claim 1 or 2, characterised in that the tubes are designed as circular, oval or flat tubes (4) arranged in one or more rows and accommodated in the at least one tube sheet (2), and in that the reinforcing ribs (6) are arranged on the longitudinal walls (3a) of the plastic case (3) in a spacing corresponding to the spacing of the tubes or of external fins.
4. Heat exchanger according to claim 3, characterised in that each of the reinforcing ribs (6) is arranged at the height of the tubes (4).
5. Heat exchanger according to claim 3, characterised in that each of the reinforcing ribs (6) is arranged between the tubes (4).
6. Heat exchanger according to any of the preceding claims, characterised in that the transitional region (9) is corrugated in design and has indentations (10) as well as bulges (11) on the inside and recessed areas on the outside of the plastic case (7, 13) in which parts of the tube sheet engage positively.
7. Heat exchanger according to claim 6, characterised in that the reinforcing ribs (8) are arranged above the indentations (10).
8. Heat exchanger according to claim 6, characterised in that the reinforcing ribs (8) are arranged in the region of the bulges (11) and between the indentations (10).
9. Heat exchanger according to any of the preceding claims, characterised in that the reinforcing ribs (8, 8, 12) have rib surfaces arranged parallel to the demoulding direction of the case (3, 7, 13).

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