Cooling system, and internal combustion engine comprising a cooling system of said type

Abstract

A cooling system including a first coolant line and a second coolant line, at least one first component to be cooled, into which the first coolant line opens, and a first ventilation line. The first ventilation line is fluidically connected to the at least one first component and is configured for ventilating the at least one first component. The first ventilation line opens into the second coolant line.

Claims

1. A cooling system, comprising: a first coolant line and a second coolant line; at least one first component to be cooled, into which the first coolant line opens, the at least one first component being in the form of a turbine housing of an exhaust-gas turbocharger; a second component to be cooled, the second component being in the form of a compressor housing of the exhaust-gas turbocharger; and a first ventilation line fluidically connected to the at least one first component and configured for ventilating the at least one first component, the first ventilation line opens into the second coolant line, wherein the second coolant line is formed as a coolant path in the second component.

2. The cooling system of claim 1 wherein the first ventilation line opens into the second coolant line outside of at least one of said at least one first component and the second component to be cooled.

3. The cooling system of claim 1, wherein a first pressure prevails in the first coolant line, a second pressure prevails in the second coolant line, wherein the first pressure of the first coolant line is higher than the second pressure of the second coolant line.

4. The cooling system of claim 1, wherein said first coolant line has a first cross-sectional area, said first ventilation line has a second cross-sectional area, wherein the first cross-sectional area is larger than the second cross-sectional area by a factor of one of 16 to 400, 25 to 225, and 36 to 100.

5. The cooling system of claim 1, wherein said first ventilation line is fluidically connected to said at least one first component at a connection point which is arranged higher than an opening-in point of said first coolant line into said at least one first component.

6. The cooling system of claim 1, wherein the cooling system further includes an air separator which is arranged downstream of an opening-in point of the first ventilation line into the second coolant line.

7. The cooling system of claim 6, wherein the cooling system further includes a second ventilation line fluidically connected to said air separator.

8. The cooling system of claim 7, wherein said air separator has a separation means which is designed to separate air out of a coolant flow passing through the air separator and to supply said air to said second ventilation line.

9. The cooling system of claim 7, wherein the cooling system further includes an expansion tank, and at least one of the second coolant line and the second ventilation line open into said expansion tank of the cooling system.

10. The cooling system of claim 9, wherein the second coolant line is arranged spatially closer to said expansion tank than said at least one first component.

11. An internal combustion engine, comprising: a cooling system, including: a first coolant line and a second coolant line; at least one first component to be cooled, into which the first coolant line opens, the at least one first component being in the form of a turbine housing of an exhaust-gas turbocharger; a second component to be cooled, the second component being in the form of a compressor housing of the exhaust-gas turbocharger; and a first ventilation line fluidically connected to the at least one first component and configured for ventilating the at least one first component, the first ventilation line opens into the second coolant line, wherein the second coolant line is formed as a coolant path in the second component.

12. The internal combustion engine of claim 11, wherein said cooling system further includes a second component to be cooled, and said second coolant line is formed as a coolant path in the second component.

13. The internal combustion engine of claim 12, wherein the first ventilation line opens into the second coolant line outside of at least one of said at least one first component and the second component to be cooled.

14. The internal combustion engine of claim 11, wherein a first pressure prevails in the first coolant line, a second pressure prevails in the second coolant line, wherein the first pressure of the first coolant line is higher than the second pressure of the second coolant line.

15. The internal combustion engine of claim 11, wherein said first coolant line has a first cross-sectional area, said first ventilation line has a second cross-sectional area, wherein the first cross-sectional area is larger than the second cross-sectional area by a factor of one of 16 to 400, 25 to 225, and 36 to 100.

16. The internal combustion engine of claim 11, wherein said first ventilation line is fluidically connected to said at least one first component at a connection point which is arranged higher than an opening-in point of said first coolant line into said at least one first component.

17. The internal combustion engine of claim 11, wherein the cooling system further includes an air separator which is arranged downstream of an opening-in point of the first ventilation line into the second coolant line.

18. A cooling system, comprising: a first coolant line and a second coolant line; at least one first component to be cooled, into which the first coolant line opens; and a first ventilation line fluidically connected to the at least one first component and configured for ventilating the at least one first component, the first ventilation line opening directly into the second coolant line, wherein the second coolant line is formed as a coolant path in the second component such that air discharged from the at least one first component is not led directly to one of a bubble separator and an expansion tank.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 is a schematic illustration of an embodiment of an internal combustion engine with a cooling system;

(3) FIG. 2 is an illustration of another embodiment of an internal combustion engine with a cooling system;

(4) FIG. 3 is an illustration of another view of the internal combustion engine as per FIG. 2;

(5) FIG. 3D is a detail view of the internal combustion engine as shown in FIG. 3; and

(6) FIG. 4 is a sectional illustration through an embodiment of an air separator of an embodiment of a cooling system according to the present invention.

(7) Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 is a schematic illustration of a first exemplary embodiment of an internal combustion engine 1 with a cooling system 3. The cooling system 3 has a first component 5 to be cooled, into which a first coolant line 7 opens. A first ventilation line 9, which is different from the first coolant line 7, is fluidically, i.e. fluidly, connected to the first component 5 for the purposes of ventilating the latter. The first ventilation line 9 opens into a second coolant line 11.

(9) Here, the second coolant line 11 is formed as a coolant path 13 which is formed in a second component 15 to be cooled, for example in the form of a double-walled housing of the second component 15.

(10) Alternatively, it is also possible for the first ventilation line 9 to open, outside a component to be cooled, into a coolant line of a coolant circuit 17 of the cooling system 3. This even constitutes a variant, because then no further component is impinged on by the air ventilated from another component. However, if a geometric distance of the component to be ventilated from a skimming-off component and/or an expansion tank of the cooling system 3 is too great, it may be advantageous, with regard to ventilation lines which are as short as possible and which exhibit little susceptibility to vibrations, for ventilation to be performed into a more closely situated, further component to be cooled. By contrast, if the component to be ventilated is arranged in close proximity to an expansion tank, ventilation can be performed directly into the expansion tank.

(11) During the operation of the cooling system 3, a first pressure prevails in the first coolant line 7, which first pressure is higher than a second pressure which prevails in the second coolant line 11. The ventilation of the first component 5 may thus take place in pressure-driven fashion.

(12) The first and/or the second coolant line 7, 11 have/has a first cross-sectional area, wherein the first ventilation line 9 has a second cross-sectional area, wherein the first cross-sectional area may be larger than the second cross-sectional area, for example by a factor of at least 16, for example to at most 400, for example of at least 25 to at most 225, for example of at least 36 to at most 100, for example of at least 25 to at most 49, for example of at least 25 to at most 36.

(13) Here, the cooling system 3 has an air separator 19, which is arranged downstream of the opening-in point of the first ventilation line 9 into the second coolant line 11. A second ventilation line 21 is fluidically connected to the air separator 19. The air separator 19 has a separation means which is designed for separating off air from a coolant flow passing through the air separator 19 and supplying the air to the second ventilation line 21.

(14) The second ventilation line 21 opens in this case into an expansion tank 23 of the cooling system 3 for coolant. Here, the expansion tank 23 serves for the compensation of thermally induced volume fluctuations of the coolant in the coolant circuit 17, and as a bubble separator or separating device in which air can rise up and escape from the coolant and consequently be discharged from the coolant circuit 17. Here, the cooling system 3 may be formed as an open system or else as a closed system, wherein, in the latter case, the air is not discharged to the atmosphere but rather is collected in the expansion tank 23.

(15) The arrangement of the various components 5, 15 illustrated in FIG. 1 does not reflect the actual spatial arrangement thereof on the internal combustion engine 1, but rather serves for explaining the structure of the cooling system 3 and of the coolant circuit 17. For example, the second component 15 may be arranged in close proximity to the first component 5. Furthermore, the second component 15 may be arranged spatially closer to the expansion tank 23 than the first component 5.

(16) In the exemplary embodiment in FIG. 1, the coolant circuit 17 of the cooling system 3 includes the following elements: a multiplicity of further coolant lines are in this case denoted as a whole by the reference designation 25, in order to simplify the illustration. Furthermore, additional ventilation lines are provided, which in this case, for the sake of simplicity, are all denoted by the reference designation 27.

(17) The coolant is conveyed along the coolant circuit 17 by a conveying device 29 which may be in the form of a pump. Here, the coolant circuit 17 includes, as components to be cooled, a crankcase 31 of the internal combustion engine 1, a cylinder head 33 of the internal combustion engine 1, an exhaust line 35, a charge-air cooler 37, an oil heat exchanger 39, and the abovementioned first component 5 to be cooled, which in this case is formed as a turbine housing 41 of an exhaust-gas turbocharger 42, and the second component 15 to be cooled, which in this case is formed as a compressor housing 43 of the exhaust-gas turbocharger 42.

(18) In the exemplary embodiment illustrated here, it is thus the case that the turbine housing 41 is ventilated via the first ventilation line 9 into the compressor housing 43.

(19) The coolant circuit 17 furthermore has a coolant heat exchanger 45 for the purposes of cooling the coolant.

(20) It is now shown that certain components can be ventilated into other components, in this case the turbine housing 41 can be ventilated into the compressor housing 43, wherein the air that is then ventilated into the second coolant line 11 is transported onward via the second coolant line and is finally fed again, between the charge-air cooler 37 and the air separator 19, into a further coolant line 25 which leads to the air separator 19, wherein the air is then separated off from the coolant flow in the air separator 19 and supplied via the second ventilation line 21 to the expansion tank 23.

(21) Other components, which may be arranged in closer proximity to the air separator 19, may be ventilated directly into the coolant line 25, which is fluidically connected directly to the air separator 19, between the charge-air cooler 37 and the air separator 19, without the ventilated air previously being conducted through a further component to be cooled. This is the case for example with the charge-air cooler 37 itself and with the crankcase 31. The ventilated air or the air/coolant mixture flowing along the ventilation line 27 is, upstream of the air separator 19 and spaced apart from the latter, fed into the coolant line 25, in order that the air has time to rise up in the coolant line 25 before reaching the air separator 19 and to thus be separated off particularly efficiently in the air separator 19.

(22) Further components to be cooled, for example components which are arranged in relatively close proximity to the expansion tank 23, are ventilated directly via ventilation lines 27 into the expansion tank 23. This is additionally the case here in particular for the crankcase 31, for the exhaust line 35 and for the oil heat exchanger 39.

(23) In general, the ventilation lines 9, 21, 27 may be led so as to be of the shortest possible form, such that they do not exhibit a tendency to oscillate. Furthermore, the number of ventilation lines 9, 21, 27 can be considerably reduced in relation to known embodiments of a cooling system.

(24) The expansion tank 23 can be arranged at a geodetically highest point of the cooling system 3, such that the air can rise up to the expansion tank 23 through the ventilation lines 21, 27, wherein a backflow of air into the ventilation lines 21, 27 is prevented.

(25) It is also shown that a further coolant line 25 branches off, as a third line, from the first component 5 to be cooled in order to again discharge the coolant, which is supplied through the first coolant line 7 for cooling purposes, from the component 5 to be cooled. Here, it is clear that the first ventilation line 9 serves neither for the supply nor for the discharge of coolant, but rather in fact serves specifically for ventilation of the first component 5. This is not opposed by the fact that coolant entrained by the ventilated air may possibly also be conducted along the ventilation line 9. The air/coolant mixture that is conducted along the first ventilation line 9 is in any case very much richer in air, and at the same time has less coolant, than a coolant/air mixture possibly discharged from the first component 5 along the coolant line 25, if the coolant conducted along the coolant line 25 still contains any air at all.

(26) FIG. 2 is an illustration of a second exemplary embodiment of an internal combustion engine 1 with a cooling system 3. Identical and functionally identical elements are denoted by the same reference designations, such that, in this respect, reference is made to the preceding description. Here, two exhaust-gas turbochargers 42.1, 42.2 are provided with in each case one turbine housing 41.1, 41.2 as respective first component 5.1, 5.2 to be cooled, wherein the first components 5.1, 5.2 are each ventilated through a very short, first ventilation line 9.1, 9.2 into a respective compressor housing 43.1, 43.2. Also illustrated is a further ventilation line 27, through which a coolant line (not illustrated) of an exhaust line 35 is ventilated. Furthermore, the expansion tank 23 is illustrated.

(27) It becomes clear here that the first ventilation lines 9.1, 9.2 are fluidically connected to the first components 5.1, 5.2 at connection points 47.1, 47.2 which are arranged geodetically above opening-in points (not illustrated here) of the first coolant lines (likewise not illustrated), for example at a geodetically highest point of the first components 5.1, 5.2. This permits particularly efficient ventilation of the first components 5.1, 5.2. In general, ventilation lines can be arranged at geodetically upper, for example geodetically highest, points of components to be ventilated.

(28) FIG. 3 is an illustration of the embodiment of the internal combustion engine 1 with the cooling system 3 as per FIG. 2 from another perspective and with an enlarged detail FIG. 3D. Identical and functionally identical elements are denoted by the same reference designations, such that, in this regard, reference is made to the preceding description. Here, in particular, ventilation lines 27 are illustrated which branch off from a crankcase 31 and which open, upstream of an air separator 19, into a coolant line 25 which opens into the air separator, such that the air that is ventilated from the crankcase 31 is supplied through the coolant line 25 to the air separator 19. The air can then be separated from the coolant in the air separator 19 and can be supplied through the second ventilation line 21 to the collecting vessel 23.

(29) Also illustrated are further ventilation lines 27 which lead directly into the collecting vessel 23 from other components to be cooled. For example, a ventilation line 27 leads from the oil heat exchanger 39 directly into the collecting vessel 23.

(30) A comparison of FIGS. 2 and 3 shows that the crankcase 31 is arranged closer to the air separator 19 than the turbine housings 41.1, 41.2 as first components 5.1, 5.2 to be ventilated. It is therefore expedient for the crankcase 31 to be ventilated directly into a coolant line 25 which opens into the air separator 19, whereas the turbine housings 41.1, 41.2 are initially ventilated into the compressor housings 43.1, 43.2. Thus, where possible, use can be made of the shortest and fewest possible ventilation lines throughout.

(31) FIG. 4 shows an embodiment of the air separator 19. The air separator 19 has a separation means 49 which in this case is in the form of a lamella. Identical and functionally identical elements are denoted by the same reference designations, such that, in this respect, reference is made to the preceding description. The separation means 49 is designed to branch off air from a coolant flow passing through the air separator 19 along an arrow P and supply the air to the second ventilation line 21, which in this case is illustrated in the form of an opening-in bore into the air separator 19. Accordingly, a part 51 of the air separator 19 arranged downstream of the separation means 49 conducts little or even no air, such that, downstream of the air separator 19, efficient cooling of a component to be cooled is realized.

(32) Air encompassed by the coolant, on its path through the air separator 19 and even before this through a coolant line 25 connected thereto, becomes concentrated geodetically at the top, for example on a geodetically upper, first side 53 of the separation means 49. The air thus always impinges on the separation means 49 so as to be conducted along the first side 53 into the second ventilation line 21 and be discharged from there. By contrast, the coolant flows along a geodetically lower, second side 55 of the separation means 49 through the air separator 19, and through that part 51 which is arranged downstream of the separation means 49, further along the coolant circuit.

(33) It is possible for the air separator 19 to be arranged directly upstream of the coolant heat exchanger 45.

(34) Altogether, it is shown that, by means of the cooling system 3 proposed here and the internal combustion engine 1, highly efficient cooling is possible, while avoiding long ventilation lines, which are susceptible to vibrations, and with optimized ventilation.

(35) While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.