Method for producing a cylinder head with a water cooling system for cooling the combustion chambers and the exhaust outlet fluid path

Abstract

Method for producing a cylinder head (1) of an internal combustion engine (3), comprising: - a plurality of combustion chambers (31) for chemically reacting a fuel with fresh air, releasing heat and mechanical energy, - a common exhaust gas outlet fluid path (59) associated with at least two of the plurality of combustion chambers (31), by means of which exhaust gases generated during the conversion in the at least two combustion chambers (31) can be discharged, - a water cooling system (5) for cooling the combustion chambers (31) and the exhaust gas outlet fluid path (59), wherein the water cooling system (5) has an exhaust gas outlet cooling fluid path (53) which is adapted at least in regions to an outer contour (61) of the exhaust gas outlet fluid path (59), characterized in that the cylinder head (1) is produced by casting, wherein a combustion chamber water jacket (17) is formed by means of a second sand core (39) and an exhaust gas water jacket (15) with the exhaust gas outlet cooling fluid path (53) is formed by means of a first sand core (37), wherein the exhaust gas outlet cooling fluid path (53) surrounds the exhaust gas outlet fluid path (59) in an annular manner.

Description

[0001] The invention relates to a method for producing a cylinder head of an internal combustion engine having a plurality of combustion chambers for chemically reacting a fuel with fresh air while releasing heat and mechanical energy, a common exhaust gas outlet fluid path assigned to at least two of the plurality of combustion chambers, by means of which exhaust gases generated during the reaction in the at least two combustion chambers can be discharged, and a water cooling system for cooling the combustion chambers and the exhaust gas outlet fluid path.

[0002] Cylinder heads of an internal combustion engine and methods for cooling such cylinder heads are known. These can have an integrated exhaust manifold or cast-in exhaust ports, with individual ports of associated combustion chambers being combined into a single port within the cylinder head itself. The cylinder head itself therefore contains an additional function of the integrated exhaust manifold. The integrated exhaust manifold and the cylinder head can be made of a common material, for example, aluminum. For corresponding production, for example by casting, an exhaust core forming the integrated exhaust manifold can be inserted through a water jacket of the cylinder head. It is also known to associate an exhaust gas turbocharger with the single port, for example by means of a flange. High temperatures arise in the area of ​​the single port, the flange, and the exhaust gas turbocharger.

[0003] DE 10 2008 057 338 A1 discloses such a cylinder head with a cast-in exhaust manifold, wherein a common cooling water jacket serves for the joint cooling of combustion chambers and exhaust manifold.

[0004] DE 10 2007 012 089 A1 shows a cylinder head with a head casting that defines a main cooling jacket serving to cool the cylinder head casting. The head casting defines an upper and a lower cooling jacket that are in heat exchange relationship with an exhaust manifold.

[0005] DE 10 2004 050 923 A1 discloses a cylinder head for an internal combustion engine with a lower cooling jacket and an upper cooling jacket and an exhaust manifold arranged therebetween.

[0006] DE 195 08 985 C1 discloses a cylinder head for a liquid-cooled internal combustion engine in which a cooling water chamber is penetrated by an intermediate ceiling which separates the cooling water chamber into an upper and a lower cooling water chamber.

[0007] The object of the invention is to enable a method for producing a cylinder head with an integrated exhaust manifold with improved cooling, in particular if an exhaust gas turbocharger can be connected downstream of the integrated exhaust manifold.

[0008] The problem is solved by a method having the features of independent claim 1.

[0009] In a method for cooling an internal combustion engine having a cylinder head with a plurality of combustion chambers for chemically reacting a fuel with fresh air while releasing heat and mechanical energy, a common exhaust gas outlet fluid path assigned to at least two of the plurality of combustion chambers, by means of which exhaust gases generated during the reaction in the at least two combustion chambers can be discharged, and a water cooling system for cooling the combustion chambers and the exhaust gas outlet fluid path, an outer contour of the exhaust gas outlet fluid path is flushed at least partially with a cooling medium of the water cooling system. Particularly uniform cooling of the exhaust gas outlet fluid path can advantageously be achieved.

[0010] In one embodiment of the method, an annular flushing of the outer contour is provided. Advantageously, the outer contour can be cooled completely and uniformly.

[0011] In a cylinder head of an internal combustion engine having a plurality of combustion chambers for chemically reacting a fuel with fresh air to release heat and mechanical energy, a common exhaust gas outlet fluid path assigned to at least two of the plurality of combustion chambers, by means of which exhaust gases generated during the reaction in the at least two combustion chambers can be discharged, and a water cooling system for cooling the combustion chambers and the exhaust gas outlet fluid path, the water cooling system has an exhaust gas outlet cooling fluid path that is at least partially adapted to an outer contour of the exhaust gas outlet fluid path. Advantageously, a cooling medium can flow through the exhaust gas outlet cooling fluid path, wherein uniform cooling of the exhaust gas outlet fluid path is possible due to the adaptation to the outer contour. Advantageously, this can reduce a component temperature below a critical level in the case of a downstream or flange-mounted exhaust gas turbocharger.The curvature can be created, for example, during a casting process using an insertable core. Advantageously, no drilling or similar processes are required. Uniform cooling ensures that the coolant does not boil.

[0012] It is provided that the exhaust outlet cooling fluid path surrounds the exhaust outlet fluid path in a ring-shaped manner. Advantageously, the annular exhaust outlet cooling fluid path can be arranged adjacent to the flange accommodating the exhaust turbocharger, whereby the entire flange can advantageously be cooled evenly.

[0013] In a further embodiment of the cylinder head, the exhaust gas outlet cooling fluid path has at least one inlet and at least one outlet, by means of which a cooling medium can be supplied to and removed from the water cooling system. Advantageously, the inlet and outlet can be arranged opposite one another, for example, so that they divide the exhaust gas outlet cooling fluid path approximately into two semicircles, through which the cooling medium can advantageously flow evenly, resulting in particularly uniform cooling of the exhaust gas outlet fluid path.

[0014] In a further embodiment of the cylinder head, an exhaust manifold integrated into the cylinder head is connected between the exhaust gas outlet fluid path and the combustion chambers. An exhaust manifold can be understood as a fluid path system that collects exhaust gases from at least two of the combustion chambers, preferably all combustion chambers, and combines them into the common exhaust gas outlet fluid path. This function can advantageously be fulfilled by the cylinder head alone. No additional components are required.

[0015] In a further embodiment of the cylinder head, the water cooling system comprises a combustion chamber water jacket surrounding the combustion chambers and an exhaust gas water jacket surrounding the exhaust manifold. Advantageously, both the combustion chambers and the integrated exhaust manifold can be cooled.

[0016] In a further embodiment of the cylinder head, the exhaust outlet cooling fluid path is connected to the exhaust water jacket. Advantageously, no additional fluid paths are required to connect the exhaust outlet cooling fluid path. Rather, it can be easily connected to the exhaust water jacket.

[0017] In a further embodiment of the cylinder head, it is provided that the cylinder head can be manufactured by casting, wherein the combustion chamber water jacket can be formed by means of a second sand core, and the exhaust water jacket with the exhaust outlet cooling fluid path can be formed by means of a first sand core. Advantageously, the exhaust water jacket and the exhaust outlet cooling fluid path can be formed by means of a common sand core.

[0018] In a further embodiment of the cylinder head, the combustion chamber water jacket and the exhaust gas water jacket are connected in series. Advantageously, a flow of the cooling medium can be guided through the series-connected water jackets and thus also through the exhaust gas outlet cooling fluid path.

[0019] In another embodiment of the cylinder head, the combustion chamber water jacket and the exhaust water jacket are connected in parallel. This parallel connection advantageously allows for higher volume flows and thus higher cooling capacities.

[0020] The problem is also solved in an internal combustion engine with a cylinder head as described above. This results in the advantages described above.

[0021] Further advantages, features, and details will become apparent from the following description, which describes an exemplary embodiment in detail with reference to the drawing. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0022] They show: Fig. 1 a circuit diagram of a cooling system for a cylinder head with an integrated exhaust manifold and a parallel connection of a cooling system for combustion chambers and the integrated exhaust manifold; Fig. 2 a further schematic view of a cooling system of a cylinder head analogous to the Fig. 1, whereby the cooling of the combustion chambers and the integrated exhaust manifold are connected in series; Fig. 3 is a schematic view of sand cores for producing a cylinder head with an integrated exhaust manifold; Fig. 4 a three-dimensional view of a cooling system for combustion chambers and an integrated exhaust manifold, which is provided by means of the Fig. 3 shown sand cores; Fig. 5 another three-dimensional view of the Fig. 4 shown cooling; and Fig. 6 another three-dimensional view and a detailed view of a current limiting device of a cylinder head cooling system analogous to Fig. 4 and Fig. 5, whereby the cooling of the combustion chambers and the cooling of the integrated exhaust manifold are connected in series.

[0023] Fig. 1 shows a schematic view of a cylinder head 1 of an internal combustion engine 3 (not shown in detail), which can be cooled by means of a water cooling system 5. The water cooling system 5 has a drive source 7 for moving a cooling medium. The drive source 7 is mechanically assigned to the internal combustion engine 3 by means of a toothed belt drive, wherein the toothed belt drive drives a water pump. A cylinder crankcase 9 of the internal combustion engine 3 is connected downstream of the drive source 7. Furthermore, the cylinder head 1 and an integrated exhaust manifold 11 of the cylinder head 1 are connected downstream of the drive source 7. The water cooling system 5 has a housing cooling system 13, an exhaust water jacket 15, and a combustion chamber water jacket 17. The housing cooling system 13, the exhaust water jacket 15, and the combustion chamber water jacket 17 are connected downstream of the drive source 7 in a parallel circuit.For separate control and / or regulation, a housing thermostat 19 is connected downstream of the housing cooling system 13 or in a parallel branch of the housing cooling system 13. Furthermore, the water cooling system 5 has an oil cooling system 21 for cooling an operating fluid of the internal combustion engine, in particular engine oil, a heating heat exchanger 23 for heating an interior of a motor vehicle driven by the internal combustion engine 3, and, downstream of the latter and upstream of the drive source 7, a cooler 25 for dissipating heat to the environment. A thermostat 27 and a throttle element 29 are provided to form an internal cooling circuit and an external cooling circuit and are connected accordingly in the water cooling system 5.

[0024] For cooling the combustion chambers 31 of the internal combustion engine 3, a common line 33 is provided downstream of the drive source 7 and upstream of the combustion chamber water jacket 17. The combustion chamber water jacket 17 can be supplied with the cooling medium via the common line 33.

[0025] Fig. 2 shows a schematic view of another water cooling system 5 analogous to that shown in Fig. 1 shown water cooling 5. In the following only the differences are discussed.

[0026] In contrast, the exhaust water jacket 15 and the combustion chamber water jacket 17 are not connected completely in parallel, but at least partially in series. For this purpose, the exhaust water jacket 15 is connected downstream of the combustion chambers 31 and the combustion chamber water jacket 17, respectively. As a further difference, a flow-limiting device 35 is connected downstream of the combustion chamber water jacket 17 and parallel to the exhaust water jacket 15. By means of the flow-limiting device 35, a partial flow of the cooling medium conveyed by the drive source 7, which has already passed through the exhaust water jacket 15, can be guided past the combustion chamber water jacket 17. This makes it possible to set different volume flows or cooling capacities at the exhaust water jacket 15 and the combustion chamber water jacket 17, with a higher volume flow flowing through the combustion chamber water jacket 17 than through the exhaust water jacket 15.The volume flow portion not flowing through the exhaust water jacket 15 is guided through the flow limiting device 35.

[0027] Fig. 3 shows a three-dimensional view of a first sand core 37 for producing the exhaust water jacket 15, a second sand core 39 for producing the combustion chamber water jacket 17 and the common line 33. In addition, Fig. 3 a third sand core 41 for producing the integrated exhaust manifold 11. An arrow 43 indicates that the second sand core 39 and the third sand core 41 can be pushed together into the first sand core 37, so that the integrated exhaust manifold 11, the exhaust water jacket 15 and the combustion chamber water jacket 17 can be cast or produced in a later casting process.

[0028] Fig. 4 shows a three-dimensional view of the sand cores 37 - 41 of the Fig. 3 producible fluid paths of a cylinder head 1 of an internal combustion engine 3. The Fig. 4 are arranged according to the circuit diagram of the Fig. 1. The cooling medium can be supplied to the common line 33 via a coolant inlet 45 that can be connected downstream of the drive source 7. The combustion chamber water jacket 17 can be supplied with the cooling medium via the common line 33.

[0029] The common line 33 is assigned a web 47, via which the cooling medium can be supplied to the exhaust water jacket 15. The common line 33 and the web 47 form a common supply line, with the combustion chamber water jacket 17 and the exhaust water jacket 15 connected in parallel.

[0030] The exhaust water jacket 15 is, in alignment with the Fig. 4, flows from left to right, which is indicated by an arrow 49. Via a common coolant outlet 51, which is arranged downstream of the exhaust water jacket 15 and the combustion chamber water jacket 17, the cooling medium can be discharged again and ultimately fed to the cooler 25 when the large cooling circuit is open.

[0031] Fig. 5 shows another view of the Fig. 4 illustrates the fluid paths of the water cooling system 5 of the cylinder head 1. It can be seen that an exhaust outlet cooling fluid path 53 is connected to the exhaust water jacket 15. The exhaust outlet cooling fluid path 53 is annular and preferably has two inlets 55 and two outlets 57. Alternatively or additionally, however, more or fewer inlets and outlets in any desired combination are also conceivable.

[0032] Advantageously, by means of the exhaust outlet cooling fluid path 53, a Fig. 5 not shown in detail, but can be seen from the Fig. 3. The exhaust gas outlet cooling fluid path 53 is advantageously adapted to an outer contour 61 of the exhaust gas outlet fluid path 59 and surrounds this contour 61 in an annular manner. This advantageously allows for particularly uniform and effective cooling of the exhaust gas outlet fluid path 59, in particular of a flange arranged adjacent to the exhaust gas outlet fluid path 59.

[0033] Fig. 6 shows a three-dimensional view of a water cooling system 5 of a cylinder head 1 of an internal combustion engine 3 analogous to that shown in Fig. 5 shown water cooling 5. In contrast, the water cooling 5 according to Fig. 6 analogous to the representation of the Fig. 2. In the following, only the differences are discussed. It can be seen that instead of the Fig. 5 visible web 47, the exhaust water jacket 15 is assigned directly to the combustion chamber water jacket 17 or a return area of ​​the combustion chamber water jacket 17 by means of a connection 63. The resulting flow direction of the cooling medium within the exhaust water jacket 15 is indicated by the arrow 49 in Fig. 6. By means of a further arrow 65, a flow direction of the return area of ​​the combustion chamber water jacket 17 is indicated in Fig. 6. It can be seen that the cooling medium first passes through the common line 33, then through the combustion chamber water jacket 17 and then through the exhaust gas water jacket 15.

[0034] The Fig. The flow limiting element 35 shown in Figure 2 is implemented by means of throttle ribs 67, wherein the throttle ribs 67 are connected between the return flow area of ​​the combustion chamber water jacket 17 and the coolant outlet 51. By means of a further connection 69, the exhaust water jacket 15 is assigned to the coolant outlet 51.

[0035] Via the throttle ribs 67, a partial volume flow of the cooling medium already guided through the combustion chamber water jacket 17, i.e. bypassing the exhaust gas water jacket 15, can be fed directly to the coolant outlet 51, which in Fig. 6 is indicated by an arrow 71. The remaining partial volume flow is also fed to the coolant outlet 51 via the return area, the connection 63, the exhaust water jacket 15 and finally the further connection 69.

[0036] At the Fig. 5, a comparatively higher volume flow, for example between 150 l / min and 170 l / min, in particular approximately 160 l / min, can advantageously be achieved at a lower differential pressure, for example of approximately 500 - 600 mbar, in particular approximately 550 mbar. In the case of the Fig. In the series circuit shown in Figure 6, the pressure difference can be, for example, between 600 mbar and 650 mbar, in particular approximately 625 mbar, resulting in a volume flow of approximately 140 l / min - 160 l / min, in particular approximately 150 l / min.

[0037] The exhaust water jacket 15 advantageously has the cast-in exhaust outlet cooling fluid path 53, which is routed around the exhaust outlet fluid path 59 and thereby advantageously cools a flange surface for an exhaust gas turbocharger (not shown in detail). The inlets 55 and the outlets 57 extend radially onto the exhaust outlet cooling fluid path 53, which is designed as an annular channel. The inlets 55 and the outlets 57 can advantageously be realized by means of core bearings necessary for a manufacturing process or casting process of the cylinder head 1. Advantageously, the core bearings not only fulfill a casting function, but are also necessary for the function of the exhaust water jacket 15.

[0038] Advantageously, the three sand cores 37-41 can be placed separately in a mold of a corresponding casting tool. This is advantageous because the first sand core 37 for forming the exhaust water jacket 15 is separate from the second sand core 39 and / or the third sand core 41 for producing the combustion chamber water jacket 17 and / or the integrated exhaust manifold 11.

[0039] The cooling medium can be supplied according to the Fig. 1 and Fig. 2 by means of a parallel connection or a series connection. In the case of the parallel connection, which is Fig. 5, a supply of the cooling medium or a flow from a coolant distribution bar or the common line 33, which can be arranged, for example, in the cylinder crankcase 9, takes place via a cast-in channel or the web 47 into a flow of the integrated exhaust manifold 11. A return takes place via a similar channel or the further connection 69, which is also shown in Fig. 5 is provided. The further connection 69 connects the return of the exhaust water jacket 15 with the return area of ​​the combustion chamber water jacket 17 or a so-called collecting strip of the combustion chamber water jacket 17 of the cylinder head 1.

[0040] In the Fig. 2 and Fig.In the series circuit shown in Figure 6, the cooling medium is connected to the flow of the exhaust water jacket 15 via the manifold or connection 63. The return flow occurs via the further connection 69, analogous to the parallel circuit described above. A volume flow via the exhaust water jacket 15 can be adjusted via throttles or the throttle ribs 67 of the flow limiting device 35. The connections 63 and 69, which connect the separate exhaust water jacket 15, which can be produced using the first sand core 37, to the manifold or to a channel that can be fed directly from the coolant distribution bar or the common line 33, can be made, for example, by mechanically drilling out the core bearings of the exhaust water jacket 15. List of reference symbols 1 cylinder head 3 combustion engine 5 Water cooling 7 Power source 9 cylinder crankcase 11 integrated exhaust manifold 13 Case cooling 15 Exhaust water jacket 17 Combustion chamber water jacket 19 Housing thermostat 21 Oil cooling 23 heating heat exchangers 25 coolers 27 Thermostat 29 Throttle organ 31 combustion chambers 33 joint management 35 Current limiting device 37 first sand core 39 second sand core 41 third sand core 43 Arrow 45 Coolant inlet 47 jetty 49 Arrow 51 common coolant outlet 53 Exhaust outlet cooling fluid path 55 inlets 57 processes 59 Exhaust outlet fluid path 61 outer contour 63 Connection 65 Arrow 67 throttle ribs 69 Connection 71 Arrow

Claims

[1] Method for producing a cylinder head (1) of an internal combustion engine (3), comprising: - a plurality of combustion chambers (31) for chemically reacting a fuel with fresh air, releasing heat and mechanical energy, - a common exhaust gas outlet fluid path (59) associated with at least two of the plurality of combustion chambers (31), by means of which exhaust gases generated during the conversion in the at least two combustion chambers (31) can be discharged, - a water cooling system (5) for cooling the combustion chambers (31) and the exhaust gas outlet fluid path (59), wherein the water cooling system (5) has an exhaust gas outlet cooling fluid path (53) adapted at least in regions to an outer contour (61) of the exhaust gas outlet fluid path (59), characterized bythat the cylinder head (1) is produced by casting, wherein a combustion chamber water jacket (17) is formed by means of a second sand core (39) and an exhaust gas water jacket (15) with the exhaust gas outlet cooling fluid path (53) is formed by means of a first sand core (37), wherein the exhaust gas outlet cooling fluid path (53) surrounds the exhaust gas outlet fluid path (59) in an annular manner. [2] Method according to claim 1, characterized by that the combustion chamber water jacket (17) and the exhaust gas water jacket (15) are connected to one another by machining at least one closure cover seat by removing a casting-technically present partition wall between the two water jackets.

Images