Heat Exchanger for an Internal Combustion Engine Comprising a Deformation in a Joining Region of Two Separating Walls, Method for Producing a Heat Exchanger and Internal Combustion Engine Comprising a Heat Exchanger

Abstract

A heat exchanger for an internal combustion engine transfers heat between fluids and includes a housing having a housing wall and a housing interior bordered at least in regions by the housing wall. The housing interior has a fluid inlet region for introducing a first fluid of the fluids into the housing interior and a fluid outlet region for discharging the first fluid out of the housing interior. The heat exchanger has at least two partition walls, which are at least substantially accommodated in the housing interior and connected to the housing wall of the housing at at least one connection region. The partition walls border at least regions of a fluid receiving chamber, through which a second fluid of the fluids can flow, in order to separate the fluids from one another. The partition walls are connected to one another at least at a joining region associated with the fluid inlet region and adjacent to the fluid receiving chamber in a main fluid flow direction of the first fluid. The partition walls also have a deformation, at least in a joining sub-region of the joining region spaced apart from the connection region, which is provided to at least reduce mechanical tension in the at least one connection region due to a temperature-dependent change in length of the joining region.

Claims

1.-10. (canceled)

11. A heat exchanger for an internal combustion engine for transferring heat between at least two fluids, comprising: a housing having a housing wall and a housing interior which is at least regionally delimited by the housing wall, and which has a fluid inlet region for introducing a first fluid of the at least two fluids into the housing interior and a fluid outlet region for discharging the first fluid from the housing interior; at least two partitions which are accommodated at least predominantly in the housing interior and which are connected to the housing wall of the housing in a connecting region, and which, for purposes of separating the at least two fluids from one another, at least regionally delimit a fluid-receiving space through which a second fluid of the at least two fluids flows, wherein the at least two partitions are connected to one another at least at a joining region which is assigned to the fluid inlet region and which adjoins the fluid-receiving space in a fluid main flow direction of the first fluid, and at least in a joining sub-region, which is spaced apart from the connecting region, of the joining region, the at least two partitions have at least one deformation provided for reducing mechanical stresses at the connecting region resulting from a temperature-induced change in length of the joining region.

12. The heat exchanger according to claim 11, wherein the at least one deformation is configured as a bulge.

13. The heat exchanger according to claim 11, wherein the at least one deformation has an undulating form.

14. The heat exchanger according to claim 11, wherein the at least one deformation is oriented in a direction that differs from the fluid main flow direction.

15. The heat exchanger according to claim 11, wherein the at least two partitions are deformed in the same direction.

16. The heat exchanger according to claim 11, wherein the at least two partitions are cohesively connected to one another at least at the at least one deformation.

17. The heat exchanger according to claim 11, wherein the at least two partitions are connected to the housing wall as a T-shaped butt joint at the connecting region.

18. A method for producing a heat exchanger having a housing with a housing wall and a housing interior at least regionally delimited by the housing wall, and with a fluid inlet region for introducing a first fluid of at least two fluids into the housing interior and a fluid outlet region for discharging the first fluid from the housing interior, wherein at least two partitions are accommodated at least predominantly in the housing interior and at least regionally delimit a fluid-receiving space through which a second fluid of the at least two fluids flows, wherein the at least two partitions are connectable to one another at least at a joining region assigned to the fluid inlet region and adjoining the fluid-receiving space in a fluid main flow direction of the first fluid, the method comprising: forming at least one deformation of the at least two partitions at least in a joining sub-region of the joining region, the joining sub-region being spaced apart from the connecting region, wherein the at least one deformation is provided for reducing mechanical stresses at the connecting region resulting from a temperature-induced change in length of the joining region; and joining the at least two partitions at the joining region after the at least one deformation has been formed.

19. An internal combustion engine comprising a heat exchanger according to claim 11.

20. The internal combustion engine according to claim 19, wherein the heat exchanger is configured as an exhaust-gas cooler of the internal combustion engine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1 is a perspective sectional representation of a partially illustrated heat exchanger of an internal combustion engine, which serves for transferring heat between two fluids, of which a first fluid is exhaust gas and a second fluid is coolant of the internal combustion engine, wherein the internal combustion engine, illustrated in highly abstract form, is assigned to a motor vehicle, likewise illustrated in highly abstract form;

[0038] FIG. 2 is an enlarged representation of a segment of the heat exchanger shown in FIG. 1;

[0039] FIG. 3 is an enlarged representation of a partially illustrated variant of the heat exchanger, in which partitions are joined together at a common joining region and have deformations which are provided for at least reducing mechanical stresses resulting from a temperature-induced change in length of the joining region; and

[0040] FIG. 4 is an enlarged representation of a further partially illustrated variant of the heat exchanger, in which multiple deformations extend collectively in undulating form over the entire joining region.

DETAILED DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 is a schematic representation of a motor vehicle K, with a likewise schematically illustrated internal combustion engine 100 that is configured for driving the motor vehicle K. The internal combustion engine 100 comprises a heat exchanger 10, which is configured as an exhaust-gas cooler, specifically as an EGR cooler of the internal combustion engine 100. So-called cooled exhaust-gas recirculation is thus possible by means of the heat exchanger 10 during the operation of the internal combustion engine 100. FIG. 2 is an enlarged representation of a segment of the heat exchanger shown in FIG. 1.

[0042] The heat exchanger 10 serves for transferring heat between two fluids. A first fluid of the two fluids is in the present case exhaust gas, whereas a second fluid of the two fluids is in the present case coolant, for example in the form of a mixture of water and antifreeze.

[0043] The heat exchanger 10 (in this case EGR cooler) comprises a housing 20 with at least one housing wall 22. The housing wall is in the present case configured as a sheet-metal part and may also be referred to as cooling jacket plate.

[0044] The housing wall 22 peripherally delimits a housing interior 24 of the housing. The housing interior 24 has a fluid inlet region 30 for the introduction of the first fluid into the housing interior 24 and has a fluid outlet region for the discharge of the first fluid from the housing interior 24. The fluid outlet region, which is not shown in any more detail here, is in the present case arranged downstream of the fluid inlet region in a fluid main flow direction x of the first fluid. The fluid main flow direction x corresponds to a direction of longitudinal extent of the heat exchanger 10. In other words, during the intended use of the heat exchanger 10, the first fluid flows through the housing interior 24 in the direction of longitudinal extent of the heat exchanger 10.

[0045] As can likewise be seen from FIGS. 1 and 2, the heat exchanger is in the present case configured as a plate-type heat exchanger.

[0046] Here, the plates of the heat exchanger 10 are formed by partitions 40, 50 that are connected to one another in pairs, specifically a first partition 40 and a second partition 50, which in the present case are configured as respective sheet-metal half-shells. A plate is thus formed by the first partition 40 and the second partition 50, wherein the heat exchanger 10 has a multiplicity of such plates, as can be seen from FIG. 1. Only a single plate, which is formed by the two partitions 40, 50, will be discussed below, but the following statements also apply in principle to the other plates of the heat exchanger 10.

[0047] The partitions 40, 50 are accommodated in the housing interior 24 and connected to the housing wall 22 at connecting regions 60, 62 that are situated opposite one another in a height (vertical) direction z of the heat exchanger 10. Here, the first partition 40 has respective partition regions 42 that are situated opposite one another in the vertical direction z, whereas the second partition 50 has partition regions 52 that are situated opposite one another in the vertical direction z. The respective partition regions 42, 52 are formed integrally on the housing wall 22. In other words, at the corresponding connecting regions 60, 62, the partition regions 42, 52 run at least predominantly parallel to the housing wall 22 and in the present case also to one another, and are connected cohesively, in particular by way of a soldered connection, to the housing wall 22 at the connecting regions 60, 62.

[0048] The partitions 40, 50 serve for separating the fluids from one another and at least regionally delimit a fluid-receiving space 70 through which the second fluid (in this case coolant) flows during the intended use of the heat exchanger 10. The fluid-receiving space 70 is also delimited regionally, specifically in the vertical direction z, oriented perpendicularly with respect to the fluid main flow direction x, of the heat exchanger 10, by the housing wall 22. In each of FIGS. 1 to 4, the fluid-receiving space 70 is concealed by the partitions 40, 50 and it is therefore not possible to see into said fluid-receiving space, but it is readily clear how the partitions 40, 50, configured as respective sheet-metal half-shells, can delimit the fluid-receiving space 70. It is accordingly possible for in each case one of the sheet-metal half-shells (partitions 40, 50) to delimit approximately one half of the fluid-receiving space 70.

[0049] The pairs of partitions 40, 50 are cohesively connected, and in this case soldered, to one another in each case at least at a joining region 80, which is assigned to the fluid inlet region 30 and which adjoins the fluid-receiving space 70 in the fluid main flow direction x of the first fluid. A gap 84 between the partitions 40, 50, which gap extends over the joining region 80, is in this case filled with metal solder, whereby the partitions 40, 50 are soldered together and the gap 84 is sealed off against an undesired escape of the second fluid (coolant, in particular cooling water) from the fluid-receiving space 70 that extends between the partitions 40, 50. Additionally, the partitions 40, 50 are also connected to one another at a further joining region which is situated opposite the joining region 80 in the fluid main flow direction x and which is assigned to the fluid outlet region, though this is not visible in all of FIGS. 1 to 4, especially as the fluid outlet region is not shown.

[0050] At the common joining region 80, the respective partitions 40, 50 are oriented in each case at an angle, specifically in the present case a right angle (90° angle), with respect to the partition regions 42, 52. The partitions 40, 50 are thus connected to the housing wall 22 in the manner of a T-shaped butt joint at the connecting regions 60, 62, as can be seen particularly clearly in FIG. 2.

[0051] FIGS. 3 and 4 show, in each case in a partial enlarged representation of a segment of the heat exchanger 10, that the partitions 40, 50 may have at least one deformation 90 or multiple deformations 90 at least in a joining sub-region 82, spaced apart from the connecting region 60, of the joining region 80. The deformations 90 are outlined by circles in FIG. 3 and by ellipses in FIG. 4 merely for the purposes of highlighting said deformations. The deformations 90 are each provided and configured to at least reduce mechanical stresses at the connecting regions 60, 62 resulting from a temperature-induced change in length of the joining region 80. Particularly failure-resistant heat transfer between the fluids is made possible by means of the deformations 90. Whereas only two deformations 90 are provided at the joining region 80 in the variant shown in FIG. 3, the variant shown in FIG. 4 has a multiplicity of deformations 90, that is to say at least three deformations 90 at the joining region 80, which deformations are distributed preferably uniformly over the joining region 80, making it possible for the temperature-induced change in length to be distributed particularly uniformly across the respective deformations 90. Merely for the sake of clarity, the deformation 90 or deformations 90 have not been shown in FIGS. 1 and 2.

[0052] In the present case, the deformations 90 are each configured as undulating bulges. Furthermore, the deformations 90 are oriented in a direction y that differs from the fluid main flow direction x. In the present case, the direction y corresponds to a transverse direction of the heat exchanger 10. It can be seen from FIGS. 3 and 4 that the partitions 40, 50 are distorted in the same direction, such that both partitions 40, 50 are each bulged in the direction y (transverse direction) at the deformations 90.

[0053] The direction y is perpendicular to a central plane M relative to which the partitions 40, 50 may be oriented at least substantially parallel. The central plane M is in the present case spanned by the fluid main flow direction x and the vertical direction z.

[0054] The fluid main flow direction x (direction of longitudinal extent of the heat exchanger 10), the direction y (transverse direction of the heat exchanger 10) and the vertical direction z are oriented in each case perpendicularly with respect to one another.

[0055] The partitions 40, 50 are cohesively connected, specifically soldered, to one another along the entire joining region 80, and thus also at the deformation 90.

[0056] In a method for producing the heat exchanger 10, at least the following steps may be performed in order to make particularly failure-resistant heat transfer between the fluids possible during the intended use of the heat exchanger 10. In a first step, the at least one deformation 90 of the at least two partitions 40, 50 is formed at least in the joining sub-region 82. In a subsequent second step, the at least two partitions 40, 50 are joined at the joining region 80 after the at least one deformation 90 has been formed.

[0057] During the production of the present heat exchanger 10, the partitions 40, 50 (sheet-metal half-shells) may be joined, in particular soldered, both to one another at the joining region 80 and to the housing wall 22 at the connecting regions 60, 62. Owing to minimum soldering widths in the design of the heat exchanger 10, the connecting regions 60, 62 constitute particularly rigid zones of the heat exchanger 10, in particular at the fluid inlet region 30. By means of the deformation 90 or the deformations 90, inadmissibly high mechanical loading, for example in the form of fluctuating temperature loading, at the connecting regions 60, 62 can be avoided. The deformation(s) 90 prevent(s) the partitions 40, 50, which are connected to the housing wall 22 in the manner of a T-shaped butt joint, from expanding to too great an extent in the vertical direction z, whereby excessive loading of the connecting regions 60, 62 can be avoided even in the presence of a highly transient flow of particularly hot exhaust gas (first fluid) through the housing interior 24. The deformations 90 constitute targeted expansion regions at which the temperature-induced change in length can take place.

[0058] The geometrical shaping by way of the deformations 90 of the sheet-metal half-shells (partitions 40, 50) results in a targeted reduction of the rigidity of the sheet-metal half shells in the joining region 80. The deformations 90 thus cause the structure of the soldered sheet-metal half shells to be made locally softer, and the sheet-metal half shells thus have a reduced ability to transmit forces to their edge regions, that is to say to the connecting regions 60, 62, in the presence of fluctuating temperature loading. The connecting regions 60, 62 are thus relieved of load in the presence of fluctuating temperature loading.

LIST OF REFERENCE DESIGNATIONS

[0059] 10 Heat exchanger [0060] 20 Housing [0061] 22 Housing wall [0062] 24 Housing interior [0063] 30 Fluid inlet region [0064] 40 First partition [0065] 42 Partition region [0066] 50 Second partition [0067] 52 Partition region [0068] 60 Connecting region [0069] 62 Second connecting region [0070] 70 Fluid-receiving space [0071] 80 Joining region [0072] 82 Joining sub-region [0073] 84 Gap [0074] 90 Deformation [0075] 100 Internal combustion engine [0076] K Motor vehicle [0077] M Central plane [0078] x Main flow direction [0079] y Direction [0080] z Height (vertical) direction