Liquid cooling system for a vehicle's internal combustion engine

Abstract

Liquid cooling system (K) for an internal combustion engine (2) of a vehicle with a cylinder head (3) having an integrated exhaust manifold (7), wherein the cylinder head (3) has at least one first cooling chamber (5) for cooling areas adjacent to a combustion chamber and at least one second cooling chamber (6) for cooling the exhaust manifold (7), wherein the first and second cooling chambers (5, 6) are separately and parallel flowable, characterized in that at least one oil cooler (14) and / or at least one vehicle radiator (15) are arranged in series with the second cooling chamber (6) in the cooling circuit (1), and that upstream of a coolant pump (12) in the area of ​​a junction (16) of a main cooling circuit (18) coming from the coolant cooler (17) and a secondary cooling circuit (19) bypassing the coolant cooler (17) a first double-acting thermostatic valve (20) is arranged,wherein the first cooling chamber (5) is connected to the secondary cooling circuit (19) via a first coolant line (22).

Description

[0001] The invention relates to a liquid cooling system for an internal combustion engine of a vehicle having a cylinder head with an integrated exhaust manifold, wherein the cylinder head has at least one first cooling chamber for cooling regions adjacent to a combustion chamber and at least one second cooling chamber for cooling the exhaust manifold, wherein the first and second cooling chambers can be flowed through in parallel, separated from one another.

[0002] US 2005 / 0087154 A1 discloses the design of an exhaust manifold integral with the cylinder head. The main cooling chamber, formed by an upper and a lower partial cooling chamber, is thermally connected to the exhaust manifold.

[0003] EP 0 856 650 A1 discloses a cooling system for an outboard motor, in which the exhaust ports leading from the combustion chamber in the cylinder head are U-shaped and the flange surfaces for connecting an exhaust manifold are located in the cylinder head plane. The exhaust manifold is formed integrally with the cylinder housing.

[0004] US 7,051,685 B2 discloses a cylinder head with an integrated exhaust manifold, wherein the exhaust manifold is surrounded by a first and a second cooling chamber, the two cooling chambers being connected to each other by integrally cast flow connections. The first and second cooling chambers are arranged one above the other.

[0005] AT 500 442 B1 describes a cylinder head for a liquid-cooled internal combustion engine with a first central cooling chamber and a second cooling chamber surrounding an integrated exhaust manifold, wherein the coolant flow through the second cooling chamber can be adjusted separately from the coolant flow through the first cooling chamber.

[0006] WO 2011 / 061248 A1 discloses a cylinder head for an internal combustion engine with liquid cooling and a liquid-cooled exhaust manifold formed integrally with the cylinder head. The cylinder head has at least a first and a second cooling chamber through which a coolant flows, and the exhaust manifold region is at least partially surrounded by the second cooling chamber. The first and second cooling chambers are fluidly connected to one another via at least one bore.

[0007] GB 2 429 763 A discloses a liquid cooling system with heat exchangers, wherein a partial cooling circuit is provided parallel to the cylinder head and cylinder block, which partial cooling circuit passes through an EGR cooler and is arranged in series through a vehicle radiator and an oil cooler, wherein a thermostatic valve is arranged upstream of a coolant cooler.

[0008] US 2013 / 0241283 A1 shows a power generator unit with an internal combustion engine and an electric machine, wherein the electric machine, its power electronics, the internal combustion engine and an oil cooler are cooled one after the other.

[0009] EP 2 309 114 A1 describes a cooling system with a cooling zone on the cylinder block side and a cooling zone on the cylinder head side. The cooling zone on the cylinder head side is connected to a return flow path to the coolant pump, which – controlled by a thermostat valve – runs through the radiator or through a bypass bypassing the radiator.

[0010] US 5,967,101 A discloses an engine cooling system with a thermostatic valve for controlling the flow through a bypass line bypassing the radiator.

[0011] It is common practice to arrange the vehicle radiator and oil cooler parallel to the cooling chamber of the exhaust manifold. To avoid disruption to the cooling system, a relatively complex cooling system is required.

[0012] The object of the invention is to improve the cooling management of an internal combustion engine as mentioned above in the simplest possible way.

[0013] According to the invention, this is achieved in that at least one oil cooler and / or at least one vehicle radiator is / are arranged in series with the second cooling chamber in the cooling circuit, and in that a first double-acting thermostatic valve is arranged upstream of a coolant pump in the region of a junction of a main cooling circuit coming from the coolant cooler and a secondary cooling circuit bypassing the coolant cooler, wherein the first cooling chamber is connected to the secondary cooling circuit via a first coolant line.

[0014] The oil cooler can be arranged in the cooling circuit upstream of the second cooling chamber, and the vehicle radiator can be arranged in the cooling circuit downstream of the second cooling chamber.

[0015] Particularly advantageously, a first partial cooling circuit leading to the first cooling chamber and a second partial cooling circuit leading to the second cooling chamber branch off downstream of a coolant pump from the common main cooling circuit.

[0016] The second cooling chamber is advantageously connected to the main cooling circuit and / or the secondary cooling circuit via a second coolant line, wherein a vehicle radiator is preferably arranged in the second coolant line.

[0017] Furthermore, it can be provided that at least one third cooling chamber arranged in the cylinder block is connected to the first cooling chamber in the cylinder head via at least one transfer channel. Preferably, the third cooling chamber is connected to the main cooling circuit via a third coolant line, with the connection to the main cooling circuit being arranged upstream of the coolant cooler. One embodiment of the invention provides for a single-acting thermostatic valve to be arranged in the third coolant line.

[0018] In another embodiment of the invention, the third cooling chamber is connected to the secondary cooling circuit and / or the first coolant circuit via a fourth coolant line. A single-acting thermostatic valve can be arranged in the fourth coolant line. Alternatively, it is also possible to arrange a second double-acting thermostatic valve in the area of ​​an intersection point of the first coolant line, the fourth coolant line, and the secondary cooling circuit.

[0019] The described design variants allow for simple cooling management, whereby the flow of the oil cooler and the vehicle radiator has no adverse effects.

[0020] The invention is explained in more detail below with reference to the figures. They show schematically: Fig. 1 to Fig. 3 a liquid cooling system for an internal combustion engine not according to the invention in a first embodiment variant; Fig. 4 to Fig. 7 shows a liquid cooling system according to the invention for an internal combustion engine in a second embodiment; Fig. 8 to Fig. 11 a liquid cooling system according to the invention for an internal combustion engine in a third embodiment; and Fig. 12 to Fig. 16 a liquid cooling system according to the invention for an internal combustion engine in a fourth embodiment.

[0021] In the figures, deactivated parts of the liquid cooling system K are shown in dashed lines. Parts with the same function are provided with the same reference numerals in the different versions.

[0022] The figures each show a liquid cooling system K with a cooling circuit 1 for a vehicle having an internal combustion engine 2 with a cylinder head 3 and a cylinder block 4, wherein at least one first cooling chamber 5 for cooling thermally critical regions adjacent to the combustion chamber and at least one second cooling chamber 6 for cooling the exhaust manifold 7 integrated into the cylinder head 3 are arranged in the cylinder head 3. Furthermore, at least one third cooling chamber 8 is provided in the cylinder block 4 for cooling the cylinders 9.

[0023] The engine-side area of ​​the liquid cooling system K is designated KM, the vehicle-side area of ​​the liquid cooling system K is designated KF.

[0024] The first and second cooling chambers 5, 6 are hydraulically flowed through in parallel by the coolant in the cooling circuit 1, with a first partial cooling circuit 10 leading to the first cooling chamber 5 and a second partial cooling circuit 11 leading to the second cooling chamber 6. The first and second partial cooling circuits 10, 11 branch off downstream of a coolant pump 12 from a common main line 13 of the liquid cooling system K.

[0025] In the second partial cooling circuit 11, an oil cooler 14 is arranged upstream of the second cooling chamber 6, and a vehicle radiator 15 is arranged downstream of the second cooling chamber. The vehicle radiator 15 can be deactivated via a bypass valve (not shown).

[0026] Upstream of the coolant pump 12, a first double-acting thermostatic valve 20 is arranged in the region of a junction 16 of a main cooling circuit 18 coming from the coolant cooler 17 and a secondary cooling circuit 19 bypassing the coolant cooler 17.

[0027] In the first three embodiments, the first and third cooling chambers 5, 8 are connected to one another via at least one transfer channel 21.

[0028] The second cooling chamber 6 is connected to the main cooling circuit 18 and / or the secondary cooling circuit 19 via a second coolant line 23, with the vehicle radiator 15 being arranged in the second coolant line 23. The third cooling chamber 8 is connected to the main cooling circuit 18 via a third coolant line 24, with the connection 25 to the main cooling circuit 18 being arranged upstream of the coolant cooler 17.

[0029] In the Fig. 1 to Fig. In the first embodiment variant not according to the invention shown in Figure 3, only a single thermostat, namely the first double-acting thermostat valve 20, is provided. Fig. 1 shows the first double-acting thermostatic valve 20 in an intermediate position in which both the main cooling circuit 18 and the secondary cooling circuit 19 are connected to the main line 13 having the coolant pump 12. Fig. 2 shows the situation when the internal combustion engine 2 is at operating temperature, with the secondary cooling circuit 19 deactivated and the entire coolant quantity being passed through the main cooling circuit 18.

[0030] Fig. 3 shows the liquid cooling system K in a cold state, with the main cooling circuit 18 deactivated and the entire coolant quantity being passed through the secondary cooling circuit 19, bypassing the coolant cooler 17.

[0031] The Fig. 4 to Fig. 7 shows a second embodiment according to the invention with various circuit options, in which, in addition to the first double-acting thermostatic valve 20, a single-acting thermostatic valve 26 is provided in the third coolant line 24. Furthermore, the first cooling chamber 5 is connected to the secondary cooling circuit 19 via a first coolant line 22.

[0032] In Fig. 4 is the first double-acting thermostatic valve 20 - analogous to Fig. 1 - In a center position, the single-acting thermostat valve 26 is open. This allows coolant to flow unhindered in both the main cooling circuit 18 and the secondary cooling circuit 19, as well as in the third coolant line 24. Unlike the first embodiment, the coolant can flow directly into the secondary cooling circuit 19 via the first coolant line 22.

[0033] Fig. Figure 5 shows the situation when the internal combustion engine 2 is cold, with the main cooling circuit 18 closed by the first double-acting thermostat valve 20. The entire coolant is routed through the secondary cooling circuit 19, whereby the coolant can flow directly into the secondary cooling circuit 19 again via the first coolant line 22.

[0034] In Fig. 6, the internal combustion engine 2 is in the lower operating temperature range, with the secondary cooling circuit 19 closed and the main cooling circuit 18 opened via the first double-acting thermostat valve 20. By closing the single-acting thermostat valve 26, the cooling in the cylinder block 4 is deactivated. The coolant thus flows through the first cooling chamber 5 into the first coolant line 22 and, via the free part 19a of the secondary cooling circuit 19, reaches the main cooling circuit 18 upstream of the coolant cooler 17. In parallel, the coolant flows through the second partial cooling circuit 11, through the oil cooler 14, the second working chamber 6, and the vehicle heater core 15, and—after combining with the coolant from the first partial cooling circuit 10—also reaches the coolant cooler 17.

[0035] Fig. 7 differs from Fig. 6 in that the single-acting thermostat valve 26 is now open, activating the cooling of the cylinder block 4—in the operating temperature range of the internal combustion engine 2. The coolant flows from the cylinder head 3 via the transfer channels 21 into the third working chamber 8 and leaves the cylinder block 4 via the third coolant line 24 toward the main cooling circuit 18, where it dissipates the absorbed heat in the coolant cooler 17.

[0036] The Fig. 8 to Fig. 11 show a third embodiment according to the invention with various circuit options, in which the third cooling chamber 8 is connected to the secondary cooling circuit 19 via a fourth coolant line 27 and to the first cooling chamber 5 via the first coolant line 22. In addition to the first double-acting thermostatic valve 20, a single-acting thermostatic valve 28 is also provided in the third coolant line 24. In this embodiment, no further transfer channels 21 are provided between the first and third cooling chambers 5, 8 - the function of the transfer channels 21 is taken over by the first and fourth coolant lines 22, 27.

[0037] In Fig. 8 is the first double-acting thermostatic valve 20 - analogous to Fig. 1 and Fig. 4 - in a central position, the single-acting thermostat valve 28 is open. This allows coolant to flow unhindered in both the main cooling circuit 18 and the secondary cooling circuit 19, as well as in the third and fourth coolant lines 24, 27. Unlike the first embodiment, the coolant can flow directly into the secondary cooling circuit 19 via the first coolant line 22 and from the secondary cooling circuit 19 via the fourth coolant line 27 into the third cooling chamber 8.

[0038] Fig. Figure 9 shows the situation when the internal combustion engine 2 is cold: The first double-acting thermostat valve 20 closes the main cooling circuit 18—all coolant is routed through the secondary cooling circuit 19, allowing the coolant to flow directly into the secondary cooling circuit 19 via the first coolant line 22. The single-acting thermostat valve 28 is closed, thus preventing the flow into the first cooling chamber 8.

[0039] In Fig. 10 is the internal combustion engine 2 - analogous to Fig. 6 - in the lower operating temperature range, with the secondary cooling circuit 19 closed and the main cooling circuit 18 opened via the first double-acting thermostat valve 20. By closing the single-acting thermostat valve 28, the cooling in the cylinder block 4 is deactivated. The coolant thus flows through the first cooling chamber 5 into the first coolant line 22 and, via the free part 19a of the secondary cooling circuit 19, enters the main cooling circuit 18 upstream of the coolant cooler 17. In parallel, the coolant flows through the second partial cooling circuit 11, through the oil cooler 14, the second working chamber 6, and the vehicle radiator 15, and—after combining with the coolant from the first partial cooling circuit 10—also enters the coolant cooler 17.

[0040] In Fig. 11, the single-acting thermostat valve 28 is now open, activating the cooling of the cylinder block 4—in the operating temperature range of the internal combustion engine 2. The coolant flows from the first cooling chamber 5 of the cylinder head 3 via the first and fourth coolant lines 22, 27 into the third working chamber 8 of the cylinder block 4 and exits the cylinder block 4 via the third coolant line 24 toward the main cooling circuit 18 upstream of the coolant cooler 17.

[0041] The Fig. 12 to Fig. 16 show a fourth embodiment of the liquid cooling system K with various circuit options. Similar to the third embodiment, the third cooling chamber 8 is connected to the secondary cooling circuit 19 via a fourth coolant line 27 and to the first cooling chamber 5 via the first coolant line 22. Instead of the single-acting thermostatic valve 28, in addition to the first double-acting thermostatic valve 20, a second double-acting thermostatic valve 29 is provided at the intersection point 30 of the first and fourth coolant lines 22, 27 with the secondary cooling circuit 19. Here, too, no further transfer channels 21 are provided between the first and third cooling chambers 5, 8 - the function of the transfer channels 21 is taken over by the first and fourth coolant lines 22, 27.

[0042] In Fig. 12, both double-acting thermostatic valves 20, 29 are in the center positions. This allows coolant to flow unhindered in both the main cooling circuit 18 and the secondary cooling circuit 19, as well as in the third and fourth coolant lines 24, 27. The coolant can flow directly into the secondary cooling circuit 19 or the fourth coolant line 27 via the first coolant line 22, and from the secondary cooling circuit 19 via the fourth coolant line 27 into the third cooling chamber 8.

[0043] Fig. Figure 13 shows the situation when the internal combustion engine 2 is cold: The first double-acting thermostat valve 20 closes the main cooling circuit 18—all coolant is routed through the secondary cooling circuit 19. Furthermore, the second double-acting thermostat valve 29 closes the first and fourth coolant lines 22, 27, so that no flow passes through the first cooling chamber 5 and the third cooling chamber 8. The coolant circulates only in a small circuit through the second coolant line 11, the oil cooler 14, the second working chamber 7, the vehicle radiator 15, and the secondary cooling circuit 19.

[0044] If the operating temperature of the internal combustion engine 2 increases, the first coolant line 22 is opened first via the second double-acting thermostat valve 29, as shown in Fig. 14. As a result, the first cooling chamber 5 in the cylinder head 3 is now also flowed through, with the coolant leaving the first cooling chamber 5 through the first coolant line 22 and flowing back to the coolant pump 12 via the secondary cooling circuit 19.

[0045] If the temperature of the internal combustion engine 2 continues to rise, the secondary cooling circuit 19 leading to the coolant pump 12 is blocked between the crossing point 30 and the junction 16 by the second double-acting thermostat valve 29, as shown in Fig. 15. The coolant leaving the first working chamber 5 through the first coolant line 22 now flows through the free part 19a of the secondary cooling circuit 19 into the main cooling circuit 18 upstream of the coolant cooler 17.

[0046] Fig.16 shows the liquid cooling system K with the internal combustion engine 2 at operating temperature or hot. The first double-acting thermostat valve 20 now blocks the secondary cooling circuit 19 and opens the main cooling circuit 18. The second double-acting thermostat valve 29 is now in its intermediate position, in which the first and fourth coolant lines 22, 27 are open, allowing coolant to flow from the first coolant line 22 into both the free part 19a of the secondary cooling circuit 19 and the fourth coolant line 27. This allows flow through the first and third working chambers 5, 8. The coolant flows from the first cooling chamber 5 of the cylinder head 3 via the first and fourth coolant lines 22, 27 into the third working chamber 8 of the cylinder block 4 and leaves the cylinder block 4 via the third coolant line 24 toward the main cooling circuit 18 upstream of the coolant cooler 17.

[0047] Regardless of the positions of the thermostat valves 20, 26, 28 and 29, the oil cooler 14, the second working chamber 6 for cooling the exhaust manifold 7 and the vehicle heater core 15 are always flowed through. List of reference symbols 1 cooling circuit 2 internal combustion engine 3 cylinder head 4 cylinder block 5 first cold room 6 second cold room 7 exhaust manifold 8 third cold room 9 cylinders 10 first partial cooling circuit 11 second partial cooling circuit 12 Coolant pump 13 Main strand 14 oil cooler 15 vehicle radiators 16 Merger 17 Coolant cooler 18 Main cooling circuit 19 Secondary cooling circuit 19a free part of the secondary cooling circuit 19 20 first double-acting thermostatic valve 21 Transfer channel 22 first coolant line 23 second coolant line 24 third coolant line 25 Connection 26 single-acting thermostatic valve 27 fourth coolant line 28 Thermostatic valve 29 second double-acting thermostatic valve K Liquid cooling system KM engine-side area of ​​the liquid cooling system K KF vehicle-side area of ​​the liquid cooling system K

Claims

[1] Liquid cooling system (K) for an internal combustion engine (2) of a vehicle with a cylinder head (3) having an integrated exhaust manifold (7), wherein the cylinder head (3) has at least one first cooling chamber (5) for cooling regions adjacent to a combustion chamber and at least one second cooling chamber (6) for cooling the exhaust manifold (7), wherein the first and second cooling chambers (5, 6) can be flowed through in parallel, separated from one another, characterized bythat at least one oil cooler (14) and / or at least one vehicle radiator (15) are / is arranged in series with the second cooling chamber (6) in the cooling circuit (1), and that a first double-acting thermostatic valve (20) is arranged upstream of a coolant pump (12) in the region of a junction (16) of a main cooling circuit (18) coming from the coolant cooler (17) and a secondary cooling circuit (19) bypassing the coolant cooler (17), wherein the first cooling chamber (5) is connected to the secondary cooling circuit (19) via a first coolant line (22). [2] Liquid cooling system (K) according to claim 1, characterized by that a first partial cooling circuit (10) leading to the first cooling chamber (5) and a second partial cooling circuit (11) leading to the second cooling chamber (6) branch off from a common main line (13) downstream of the coolant pump (12). [3] Liquid cooling system (K) according to claim 2, characterized bythat the oil cooler (14) is arranged in the second partial cooling circuit (11) upstream of the second cooling chamber (6). [4] Liquid cooling system (K) according to claim 2 or 3, characterized by that the vehicle radiator (15) is arranged in the second partial cooling circuit (11) downstream of the second cooling chamber (6). [5] Liquid cooling system (K) according to one of claims 1 to 4, characterized by that the second cooling chamber (6) is connected to the main cooling circuit (18) and / or the secondary cooling circuit (19) via a second coolant line (23), wherein the vehicle radiator (15) is preferably arranged in the second coolant line (23). [6] Liquid cooling system (K) according to one of claims 1 to 5, characterized by that at least one third cooling chamber (8) arranged in the cylinder block (4) is connected to the first cooling chamber (5) in the cylinder head (3) via at least one transfer channel (21). [7] Liquid cooling system (K) according to claim 6, characterized bythat the third cooling chamber (8) is connected to the main cooling circuit (18) via a third coolant line (24), wherein the connection (25) to the main cooling circuit (18) is arranged upstream of the coolant cooler (17). [8] Liquid cooling system (K) according to claim 7, characterized by that a single-acting thermostatic valve (26) is arranged in the third coolant line (24). [9] Liquid cooling system (K) according to one of claims 1 to 8, characterized by that the third cooling chamber (8) is connected to the secondary cooling circuit (19) and / or the first coolant line (22) via a fourth coolant line (27). [10] Liquid cooling system (K) according to claim 9, characterized by that a single-acting thermostatic valve (28) is arranged in the fourth coolant line (27). [11] Liquid cooling system (K) according to claim 10, characterized bythat a second double-acting thermostatic valve (30) is arranged in the region of an intersection point (30) of the first coolant line (22), the fourth coolant line (24) and the secondary cooling circuit (19).

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