US20100089043A1

US20100089043A1 - Cooling system

Info

Publication number: US20100089043A1
Application number: US12/576,747
Authority: US
Inventors: Jörg Dittmann; Bernhard Schwalk
Original assignee: Mahle International GmbH
Current assignee: Mahle International GmbH
Priority date: 2008-10-10
Filing date: 2009-10-09
Publication date: 2010-04-15
Also published as: EP2175221A2; EP2175221B1; DE102008051268A1; EP2175221A3

Abstract

The present invention relates to a cooling system (1) for an internal combustion engine, in particular an exhaust gas cooling system in a motor vehicle, having a housing (2) in which a heat transmission device (4) is arranged in a first canal (3). The housing (2) is configured as a metal pressure die-cast housing and has according to the invention an integrated second canal (6) that is formed by housing contours (5, 5′), said second canal being configured as a bypass canal and bypassing the heat transmission device (4).

Description

The present invention relates to a cooling system for an ICE, in particular an exhaust-gas cooling system in a motor vehicle, according to the preamble of claim 1.
A cooling system of the generic kind is, for example, disclosed in document DE 10 2005 045 103 B32 in which a heat transmission device is provided in a housing. The heat transmission device consists of an upper part and a lower part from which pin-shaped ribs extend in a canal in the heat transmission device. In particular, a degree of efficiency of the cooling system is intended to hereby be increased in comparison to known solutions.
An additional such cooling system is, for example, disclosed in document DE 10 2005 045 098 A1.
Document DE 10 2004 025 185 A1 discloses an air intake canal system that has a collecting inlet canal in which a cooling system is integrated. The collecting inlet canal is divided into two separate canals for this purpose, whereby of the two canals, exhaust gas flows through a first and air flows through a second during normal operation, and whereby during normal operation, the canal through which air flows can serve as a bypass canal in the warming-up phase. The entire air intake canal system is conceived in such a manner that it can be assembled simply by placing the individual parts one atop the other. A considerably reduced quantity of parts in comparison to known systems is hereby intended to be achieved in particular.
Finally, DE 20 2006 009 464 U1 discloses a heat exchanging device having a canal through which coolant flows and a canal through which a fluid flows that is to be cooled, wherein both of the canals are separated from one another by a wall. Ribs extend from this wall into at least one of the canals, wherein each rib has a line-shaped inflow canal and two line-shaped outflow canals. The inflow and outflow canals border two continuously extending side walls of the ribs.
The present invention addresses the problem of providing for a cooling system of the generic kind an improved embodiment that is simple to manufacture as well as accurately controlled or regulated while having at the same time a structurally simple design.
This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the independent claims.
The present invention is based on the general concept of equipping a cooling system, which is for cooling exhaust gases in a motor vehicle, with a housing composed of die-cast metal and furthermore to integrate in this housing both a first canal, in which a heat transmission device is arranged, as well as a second canal that is configured as a bypass canal and that bypasses the heat transmission device. At least the second canal is configured by means of housing contours that form an integral component of the die-cast metal housing. Separate parts for realising the individual canals can thereby be dispensed with in such a manner that in order to manufacture the cooling system according to the invention, only the heat transmission device must still be positioned or arranged in the first canal and subsequent thereto the housing can then be closed, wherein upon closing the housing, wherein both of the canals are already formed owing to the housing contours that are provided in an integral manner. It goes without saying that it is also conceivable that the heat transmission device also forms an integral component of the housing, for example in the style of integrally moulded cooling ribs. Separation walls, which are to be provided separately, can thereby likewise be dispensed with, by means of which the cooling system according to the invention is configured in a structurally simple manner. Moreover, a material that is nearly unaffected by temperature is discovered the use of die-cast metal for the housing, said material itself withstanding high temperatures such as, for example, that can arise in an exhaust gas system of an internal combustion engine. The provision of the housing contours, which from at least the second canal in the housing upon assembly of said housing, can be realised by a correspondingly simple design or configuration of an injection mould. With the housing according to the invention that is configured out of die-cast metal and that owing to its configuration furthermore already forms the two canals lying therein, costly assembly processes as well as the diversity of the parts can be considerably reduced in the manufacture of the cooling system according to the invention.
In an advantageous development of the solution according to the invention, a pivotable bypass flap is provided by means of which a flow division is effected between the first and the second canal. The bypass flap is actuated or regulated by a corresponding control/regulation device and distributes the flow, which is flowing in the cooling system, to the first or second canal. In a first extremal position of the bypass flap, the entire flow flows through the first canal and not through the second canal, while the exact opposite is true in the instance of the second extremal position of the pivotable bypass flap. In stepless, adjustable intermediate positions, the flow between the two canals can be distributed in nearly any manner whatsoever. Such a pivotable bypass flap makes possible an extraordinarily precise and, with regard to the required parts, at the same time a cost-effective control of the gas flow that is flowing in the cooling system.
In an advantageous embodiment of the solution according to the invention, the housing is configured as a light alloy die-cast housing, in particular composed of aluminium die cast. Owing to its minimal density, aluminium is favoured for use in those applications in which the mass of a transportation means is concerned because this contributes to the use of motor fuel. Should alloy elements, such as, for example, magnesium, silicium, or other metals be hereby admixed, resistances can be achieved that steel can hardly outperform. Aluminium has, in addition to minimal weight, an extremely favourable heat conductivity and is thereby predestined for use in heat transmission devices. Thus, cooling contours, such as cooling ribs, can thus be integrally moulded on the housing, for example, said cooling ribs effecting a cooling of the exhaust gas stream flowing therethrough, wherein owing to the high heat conductivity of the aluminium, a particularly favourable heat exchange can be ensured.
In yet another advantageous embodiment of the solution according to the invention, the housing is configured as having two parts, wherein cooling contours, in particular cooling ribs, are configured on at least one of the two housing parts, said cooling contours protrude into the first canal, preferably perpendicular to the direction of flow. The cooling contours thereby force a flowing around of the same by means of the hot exhaust gas and an intensive heat exchange owing to their large surface. To increase their cooling effect, the cooling contours can be configured as hollow and flowed through by a cooling fluid. The cooling fluid can be withdrawn, for example, from a cooling circuit, which likewise cools the internal combustion engine, in such a manner that a warming-up phase of the internal combustion engine can be considerably reduced with the hot exhaust gas and the NO_xemissions, which are high in particular in this stage, can thereby be reduced. In general, such cooling systems can also be used for heating a passenger compartment, wherein the main focus of attention is directed to reducing the temperature of the exhaust gas prior to feeding it to a catalyst in order to thereby be able to generally decrease the pollutant emissions.
Additional important features and advantages of the invention can be found in the dependent claims, in the drawings, and in the pertinent description of the figures with reference to the drawings.
It is understood that the features described above and those to be described in what follows can be used not only in the particular cited combination; but also in other combinations or independently without departing from the scope of the present invention.

Preferred embodiments of the invention are shown in the drawings and are described in more detail in the following description, the same reference numerals referring to components which are the same or functionally the same or similar.

It is respectively schematically shown in

FIG. 1 a cooling system according to the invention in an exploded view,

FIG. 2 a a sectional representation along the sectional plane B-B,

FIG. 2 b a view of the cooling system according to the invention from above,

FIG. 2 c a sectional representation along the sectional plane A-A,

FIG. 2 d a sectional representation along the sectional plane C-C.

Corresponding to FIG. 1, a cooling system 1 according to the invention for an internal combustion engine, which cooling system is configured as an exhaust gas cooling system in a motor vehicle, has a housing 2 in which a heat transmission device 4 is arranged in a first canal 3. According to the invention, the housing 2 is configured as a die-cast metal housing and has an integrally second canal 6 moulded by housing contours 5, 5′, which is configured as a bypass canal and bypasses the heat transmission device 4. The paths of the first canal 3 and of the second canal 6 can thus be derived particularly well from the FIGS. 2 a and 2 c.
In regarding FIGS. 1 and 2 a, it is recognisable that a pivotable bypass flap 7 is provided that brings about a flow division between the first canal 3 and the second canal 6. It goes without saying that the bypass flap 7 represents merely one possible embodiment, meaning that in this instance, generally sliders, valves or similar such items can also be used. The pivotable bypass flap 7 is pivotably mounted about an axis 8 and has an adjustment lever 9 outside of the housing 2, said adjustment lever being connected to the bypass flap 7 in a rotationally fixed manner and furthermore by means of which the position of the bypass flap 7 can be adjusted. In the situation represented according to FIG. 2 a, the bypass flap 7 is situated in a first extremal position in which it blocks the second canal 6 and directs the entirety of the gas flow flowing through the cooling system 1 exclusively through the first canal 3. In a second extremal position, which is represented with a broken line according to FIG. 2 a, the bypass flap 7 would completely block the first canal 3 in such a manner that the entirety of the gas flow flowing through the cooling system 1 is directed exclusively through the second canal 6. It goes without saying that any intermediate position whatsoever is also conceivable that would effect a distribution of the gas flow flowing through the cooling system 1 to the first canal 3 and to the second canal 6.
It can be seen in FIG. 1 that the housing 2 is configured as having at least two parts and exhibits a first housing part 10 a as well as s second housing part 10 b that is sealing connected to said first housing part. In an advantageous embodiment of the solution according to the invention, cooling contours 11, in particular cooling ribs, are configured on at least one of the two housing parts 10 a, 10 b in such a manner that said cooling contours protrude into the first canal 3, preferably perpendicular to the direction of flow, and thereby force a redirection of the gas flow. In the embodiment represented according to FIGS. 1 and 2, cooling contours 11 are configured on both housing parts 10 a, 10 b and engage with one another in the assembled housing 2, as can particularly be seen according to FIG. 2 c. The cooling contours 11 represented in the sectional view according to FIG. 2 c are configured as solid, wherein it is also conceivable that the cooling contours 11 are configured to be hollow at least in part and flowed through by a cooling fluid, in particular from housing part 10 a to housing part 10 b or the converse. In particular, the cooling contours 11 can exhibit a blind hole by means of which an active cooling of the cooling contours 11 is effected and furthermore by means of which the cooling effect of the cooling system 1 is additionally improved.
The housing 2 is configured as a die-cast metal housing, wherein light metals, aluminium and alloys thereof in particular, can be used. It goes without saying that zinc or magnesium die-cast housings are also conceivable. By adding different metals to aluminium, properties that are similar to steel can be generated, while the high degree of heat conductivity that is an attribute of aluminium, continues to remain. The connection of the both of the housing parts 10 a and 10 b customarily is effected in a pressure-sealed manner, for example by means of a welding process. The selection of the die-cast metal as a material for the housing 2 is one that does not react unfavourably to the high temperatures that arise in the exhaust gas and that furthermore thereby exhibits a high degree of service performance. In using light metals for the material of the housing 2, weight can moreover be reduced, which increasingly becomes the aim with modern motor vehicles in particular owing to the continually increasing costs of power fuel.
With the cooling system 1 according to the invention, it is thus possible to form both of the cooling canals 3 and 6 exclusively by means of integral moulding with housing contours 5, 5′ connected to the housing 2 in such a manner that additional separating elements, which are both too costly and too complicated to assemble, can be dispensed with. Such a housing 2 or such housing parts 10 a and 10 b can be manufactured with almost any geometry whatsoever by means of a corresponding configuration of the pressure die casting mould and can furthermore be manufactured in a cost-effective manner.
Purely for the purpose of completeness, an exhaust gas recirculation valve 12 is shown that is integrated in the cooling system 1 or is at least cooled by a cooling jacket or directly with coolant.
The housing part 10 a and/or 10 b can additionally be provided with upper and/or lower closure head 13, which is configured out of plastic in particular, in which additional components, which are not shown, such as a thermostat valve, can be integrated or installed therein. The closure head(s) 13 can be screwed to the corresponding housing parts by means of screws 14.

Claims

1. A cooling system for an internal combustion engine, comprising:

a pressure die-casting housing, wherein a heat transmission device is provided in a first canal, wherein the housing has an integrated second canal formed by housing contours, said second canal being configured as a bypass canal and bypassing the heat transmission device.

2. The cooling system as specified in claim 1, wherein a pivotable bypass flap providing a flow division is effected between the first canal and the second canal.

3. The cooling system as specified in claim 1, wherein the housing has a first part and a second part.

4. The cooling system as specified in claim 3, wherein cooling contours, cooling ribs, are on at least one of the two housing parts, said cooling contours protruding into the first canal, generally perpendicular to the direction of flow.

5. The cooling system as specified in claim 3, wherein cooling contours are on both of the two housing parts, said cooling contours engaging with one another when the housing is in the assembled state.

6. The cooling system as specified in claim 4, wherein at least one of the cooling contours is hollow and is flowed through by a cooling fluid.

7. The cooling system as specified in claim 4, wherein at least one of the cooling contours includes a blind hole that is acted upon by a cooling fluid.

8. The cooling system as specified in claim 1, wherein the housing is a light metal pressure die-cast housing, such as an aluminium pressure die-cast housing.

9. The cooling system as specified in claim 1, wherein the housing is a magnesium or zinc pressure die-cast housing.

10. The cooling system as specified in claim 2, wherein the housing has two parts.

11. The cooling system as specified in claim 4, wherein cooling contours are on both of the two housing parts, said cooling contours engaging with one another when the housing is in the assembled state.

12. The cooling system as specified in claim 5, wherein at least one of the cooling contours is hollow and is flowed through by a cooling fluid.

13. The cooling system as specified in claim 5, wherein at least one of the cooling contours includes a blind hole that is acted upon by a cooling fluid.

14. The cooling system as specified in claim 6, wherein at least one of the cooling contours includes a blind hole that is acted upon by a cooling fluid.

15. The cooling system as specified in claim 2, wherein the housing is a light metal pressure die-cast housing, such as an aluminium, a magnesium or a zinc pressure die-cast housing.

16. The cooling system as specified in claim 3, wherein the housing is a light metal pressure die-cast housing, such as an aluminium, a magnesium or a zinc pressure die-cast housing.

17. The cooling system as specified in claim 4, wherein the housing is a light metal pressure die-cast housing, such as an aluminium, a magnesium or a zinc pressure die-cast housing.

18. The cooling system as specified in claim 5, wherein the housing is a light metal pressure die-cast housing, such as an aluminium, a magnesium or a zinc pressure die-cast housing.

19. The cooling system as specified in claim 6, wherein the housing is a light metal pressure die-cast housing, such as an aluminium, a magnesium or a zinc pressure die-cast housing.

20. The cooling system as specified in claim 7, wherein the housing is a light metal pressure die-cast housing, such as an aluminium, a magnesium or a zinc pressure die-cast housing.