Motor vehicle with an air- and liquid-cooled internal combustion engine

Abstract

The present invention relates to a motor vehicle with an internal combustion engine (20). The motor vehicle has: - a liquid cooling system for the internal combustion engine (20), wherein the liquid cooling system comprises a coolant circuit with a coolant circulating in the coolant circuit, wherein the internal combustion engine (20) is integrated into the coolant circuit so that liquid cooling of the internal combustion engine (20) is achieved, wherein the liquid cooling system comprises a radiator (31), wherein the radiator (31) is integrated into the coolant circuit for cooling the coolant circulating in the coolant circuit, an air cooling system for the internal combustion engine (20), wherein the air cooling system comprises a housing (40) with an air inlet (41) and an air outlet (42), wherein the internal combustion engine (20) is accommodated in the housing (40), wherein the air cooling system comprises a fan (50), wherein the fan (50) is configured toAir is conveyed into the housing (40) via the air inlet (41) and out of the housing (40) via the air outlet (42), thus providing air cooling for the internal combustion engine (20), wherein the cooler (31) of the liquid cooling system is arranged in the air inlet (41) of the housing (40), so that the cooler (31) is cooled by the air flowing through the air inlet (41) into the housing (40).

Description

[0001] The present invention relates to a motor vehicle with an internal combustion engine.

[0002] Due to increasing engine power and stricter legal requirements, the cooling requirements of combustion engines in motor vehicles are rising. This means that larger radiators must be installed in vehicles with increasing combustion engine power. This has the disadvantage of increased space requirements and weight. Because of the increased space requirements, the vehicle itself, especially the front section where the radiator is typically located, usually has to be larger. This, in turn, negatively impacts the vehicle's drag coefficient (Cd), which, particularly in high-performance vehicles such as sports cars, necessitates even more engine power to compensate, or a significant portion of engine power is lost to the additional cooling requirements.

[0003] Vehicles with a mid- or rear-mounted engine present the additional challenge that the coolant radiator is located at the front of the vehicle, while the combustion engine is positioned further back. This necessitates the routing of long coolant lines through the vehicle. Furthermore, it increases the required volume of coolant, which in turn leads to a higher weight due to the increased coolant demand. Pumps required to circulate the coolant through the cooling system must be relatively powerful in a mid- or rear-mounted engine with a front-mounted radiator to reliably pump the coolant from the rear to the front and back again.

[0004] In principle, motor vehicles or internal combustion engines with charge air cooling are known from the prior art. However, this charge air cooling does not serve to cool the engine itself, but rather to cool the air supplied to the internal combustion engine for combustion. DE 10 2015 101 797 A1 discloses a motor vehicle with an internal combustion engine and charge air cooling.

[0005] From WO 2011 / 073 625 A1, a motor vehicle is known whose engine is cooled by an airflow from below the motor vehicle.

[0006] DE 899 909 B discloses a motor vehicle having the features of the preamble of claim 1. EP 2 192 281 B1, JP 2004 - 270 526 A, WO 2011 / 073 625 A1, US 6 505 696 B1, DE 84 27 918 U1, EP 4 328 426 A1, DE 10 2014 118 645 A1 and DE 10 2016 204 917 B4 disclose further prior art.

[0007] Therefore, there is a need for improved cooling of an internal combustion engine in a motor vehicle, especially in the case of an internal combustion engine located in a rear or central area of ​​the motor vehicle, i.e. a rear engine or mid-engine.

[0008] This problem is solved by the subject matter of claim 1. The dependent claims relate to advantageous further developments.

[0009] The motor vehicle according to the invention has an internal combustion engine. The motor vehicle further has a liquid cooling system for the internal combustion engine, wherein the liquid cooling system comprises a coolant circuit with a coolant circulating in the coolant circuit, wherein the internal combustion engine is integrated into the coolant circuit so that liquid cooling of the internal combustion engine is achieved, wherein the liquid cooling system has a radiator, wherein the radiator is integrated into the coolant circuit for cooling the coolant circulating in the coolant circuit.Furthermore, the motor vehicle has an air cooling system for the internal combustion engine, wherein the air cooling system comprises a housing with an air inlet and an air outlet, the internal combustion engine being housed within the housing, and the air cooling system including a fan configured to draw air into the housing through the air inlet and out of the housing through the air outlet, thus providing air cooling for the internal combustion engine. The radiator of the liquid cooling system is arranged in the air inlet of the housing, so that the radiator is cooled by the air flowing into the housing through the air inlet.

[0010] The design specifically provides that the air flowing within the housing flows along the outer surface of the engine block or crankcase, thereby cooling the internal combustion engine. This air is primarily ambient air, which enters the housing through the air intake. Air cooling provides additional cooling capacity compared to liquid cooling alone.

[0011] A further advantage of the design according to the invention is that the radiator can be positioned particularly close to the combustion engine, since the air is actively drawn in by the fan. This makes it possible to relocate the radiator from its usual position in the front of the vehicle to another area, for example, the rear. It is also conceivable that the radiator could be housed in a spoiler of the vehicle, with the air intake opening accordingly into the surrounding area within the spoiler.

[0012] The fan allows the air intake to be oriented in virtually any direction. For example, it is conceivable that the air flows essentially vertically into the air intake, in the direction of the vehicle's height. Preferably, the angular deviation from the vertical direction is a maximum of 60°, more preferably a maximum of 45°, particularly preferably a maximum of 30°, and most particularly a maximum of 10°.

[0013] By positioning the radiator closer to the combustion engine, the amount of coolant required, the length of the coolant circuit piping, and / or the pumping capacity of the pump used to circulate the coolant can be reduced. This saves energy and reduces the weight of the liquid cooling system.

[0014] Another advantage of the housing is that it acoustically encapsulates the combustion engine, thus reducing perceptible engine noise, especially engine noise audible in the interior of the vehicle.

[0015] Particularly when the internal combustion engine is configured as a mid-engine, i.e., located in the central area of ​​the vehicle, and / or as a rear-engine, i.e., located in the rear area of ​​the vehicle, the design according to the invention is considered particularly advantageous. This is because, with a mid-engine or rear-engine, at least the rear axle is usually driven. Therefore, by arranging the radiator adjacent to the internal combustion engine, i.e., in the central or rear area of ​​the vehicle, additional weight is shifted to that area, weight which would otherwise typically be located in the area of ​​the front axle, namely when a front-mounted radiator is used. This has a beneficial effect on the vehicle's driving dynamics and the downforce in the area of ​​the rear driven axle.

[0016] Preferably, the motor vehicle is a sports car.

[0017] It is considered particularly advantageous if the fan is designed as a blower. In this context, a blower is understood to be, in particular, a turbomachine whose pressure ratio between the pressure and suction flanges is between 1.3 and 3.0.

[0018] It is considered particularly advantageous if the internal combustion engine is encapsulated in the housing.

[0019] Particularly for weight reasons, it is considered especially advantageous if the housing is designed entirely or partially as a sheet metal housing.

[0020] It is quite conceivable that parts of the underbody of the motor vehicle and / or parts of the internal combustion engine form components of the housing.

[0021] It is considered particularly advantageous if ambient air is drawn in via the air intake.

[0022] It is considered advantageous if the maximum airflow of the fan is at least 5000 m³ / h. 3 / h, preferably at least 8000 m 3 / h, in particular at least 10,000 m 3 / h.

[0023] The internal combustion engine can be, in particular, a mid-mounted engine or a rear-mounted engine.

[0024] It is considered particularly advantageous if the internal combustion engine is arranged in a rear area or rear section of the motor vehicle, insofar as the internal combustion engine is designed as a rear engine.

[0025] It is considered particularly advantageous if the air intake and / or air outlet are located in the rear of the vehicle. This is especially beneficial if the internal combustion engine is a mid-engine or rear-engine design, as it allows for a particularly short overall length of the coolant circuit lines and a significantly reduced overall coolant volume. Furthermore, this design achieves a particularly favorable weight distribution for a rear-wheel-drive vehicle. Another advantage is that the front of the vehicle can be designed with greater freedom, particularly in terms of its aerodynamic and / or aesthetic aspects, since a radiator is not required or even present in the front section.

[0026] It is considered particularly advantageous if the internal combustion engine has a crankshaft, with the fan, especially a fan wheel, coupled to the crankshaft to drive the fan. This allows for a particularly simple and efficient drive of the fan wheel. Furthermore, a particularly good overall package can be achieved, as the fan wheel can be positioned close to the internal combustion engine.

[0027] It is considered particularly advantageous if the crankshaft and the fan wheel can be decoupled, for example via a clutch.

[0028] It is considered particularly advantageous to have a gearbox between the crankshaft and the fan wheel. This allows for a gear reduction or reduction between the fan wheel and the crankshaft.

[0029] It is considered particularly advantageous if the transmission is a multi-stage transmission. This allows the ratio of rotational speeds between the crankshaft and the fan wheel to be changed.

[0030] It is considered particularly advantageous if a clutch is installed between the crankshaft and the fan wheel.

[0031] It is considered particularly advantageous if the motor vehicle has an exhaust system, whereby at least parts of the exhaust system are incorporated into the housing, so that air cooling of these parts is achieved by the air flowing through the housing.

[0032] The exhaust system may include one or more of the following components: an exhaust manifold, a catalytic converter, a rear silencer, a turbocharger.

[0033] It is considered particularly advantageous if the motor vehicle has a turbocharger, in particular an exhaust gas turbocharger, wherein the turbocharger is housed in the casing, so that air cooling of the turbocharger by the air flowing through the casing is achieved.

[0034] In a particularly preferred embodiment, the fan, especially the fan wheel, is arranged in the area of ​​the air outlet. Accordingly, air is drawn out of the housing by the fan and drawn in through the air inlet. Such a design has proven particularly advantageous with regard to a particularly simple coupling between the fan and the crankshaft of the internal combustion engine.

[0035] It is considered particularly advantageous if the internal combustion engine has a crankcase with internal cooling channels through which the coolant of the cooling circuit flows, and the air flowing through the housing flows along an outer surface of the crankcase. Such a design achieves particularly efficient cooling of the crankcase and thus of the internal combustion engine, since the crankcase is thereby both air-cooled and liquid-cooled.

[0036] It is considered particularly advantageous if the outer surface of the crankcase has cooling fins. In a particularly preferred embodiment, the outer surface of one or more components housed in the casing is provided with cooling fins. These cooling fins facilitate heat transfer from the respective component to the air flowing past it in the air-cooling system.

[0037] The coolant is primarily water, possibly with one or more additives. One of these additives could be, for example, an antifreeze such as monoethylene glycol.

[0038] In a particularly preferred embodiment, the housing is provided with at least one further air inlet, this further air inlet opening into the environment in the area of ​​the underbody of the vehicle, and the fan being configured to draw air into the housing via this further air inlet. This design is particularly advantageous in that it can increase the contact pressure of the vehicle on the road surface, also known as downforce.

[0039] In this context, it is considered particularly advantageous to have air guide ribs, preferably extendable ones, often also referred to as skirts, in the area of ​​the underbody. This improves airflow.

[0040] It is considered particularly advantageous if the secondary air inlet has an air inlet flap. This prevents unwanted air from escaping the secondary air inlet. The air inlet flap can be designed as a passive air inlet flap, similar to a check valve. However, the air inlet flap can also be actively controlled to move it from an open position to a closed position and vice versa.

[0041] The air cooling system is designed to operate in two modes: a first and a second. In the first mode, air is drawn into the housing via the air inlet and expelled through the air outlet. In the second mode, air is drawn into the housing via the air outlet and / or the additional air inlet and expelled through the housing. This effectively reverses the airflow direction through the housing. The second mode is particularly advantageous during cold starts, as it allows for a faster increase in operating temperature. This is because the air flowing through the cooler is heated by the combustion engine and / or the exhaust system, resulting in a quicker warming of the circulating coolant.

[0042] Furthermore, the vehicle is provided with an exhaust system, the air outlet being designed in such a way that, in the second operating mode, at least some of the gases exiting the exhaust system are drawn into the housing via the air outlet. This allows for particularly rapid heating of the combustion engine to the desired operating temperature.

[0043] It is considered particularly advantageous if the exhaust system has one or more rear silencers, whereby in the second operating mode the gases exiting the rear silencer(s) are drawn into the housing via the air outlet. In this context, it is considered particularly advantageous if the air outlet is located adjacent to the one or more rear silencers.

[0044] In connection with the first and second operating modes, it is considered particularly advantageous if a fan wheel of the fan rotates in a first direction of rotation in the first operating mode and rotates in a second direction of rotation in the second operating mode, the second direction of rotation being opposite to the first direction of rotation.

[0045] However, it is also conceivable that the housing could incorporate an additional fan, particularly an electrically driven one, which in the second operating mode would draw air from the air outlet to the air intake. With such a design, it is unnecessary to provide for a change in the fan's direction of rotation. This allows for a particularly simple and robust connection between the fan and the crankshaft of the internal combustion engine.

[0046] It is considered particularly advantageous if the air outlet at the rear of the vehicle opens into the surrounding area.

[0047] It is considered particularly advantageous if the axis of rotation of a fan wheel is parallel or nearly parallel to a longitudinal axis of the vehicle. Nearly parallel, in this context, means that the angular deviation between the vehicle's longitudinal axis and the axis of rotation is less than 5°. This allows for a particularly advantageous package. Furthermore, the air flowing from the air outlet can also be advantageously used to propel the vehicle.

[0048] In a preferred embodiment, a guiding element is provided at or in the air outlet to guide the airflow exiting the air outlet, wherein the guiding element is designed in such a way that the airflow is guided in such a way as to increase the contact pressure of the motor vehicle.

[0049] In an advantageous further development, it is provided that the motor vehicle has at least two rear silencers spaced apart in a transverse direction at the rear of the vehicle, wherein the air outlet is formed between the at least two rear silencers in a direction of view towards the rear of the vehicle.

[0050] It is considered advantageous if the fan has a fan wheel. The fan wheel preferably has a diameter of at least 10 cm, and more preferably at least 20 cm.

[0051] The following figures explain the invention in more detail with reference to exemplary embodiments, without being limited to these. They show: Fig. 1. An arrangement of a housing and an internal combustion engine housed in the housing in an interior view in a schematic representation. Fig. 2 a rear section of a motor vehicle according to a first embodiment in a side view with a rear engine housed in a casing in a schematic representation, Fig. 3 an arrangement of a housing and an internal combustion engine of a motor vehicle received in the housing according to a second embodiment in a view according to arrow III in Fig. 4 in a schematic representation, Fig. 4 the arrangement in a view according to arrow IV in Fig. 3, Fig. 5 the arrangement in a view according to arrow V in Fig. 4, Fig. 6 the order according to Fig. 3 in a perspective view, Fig. 7 a rear section of a motor vehicle according to a third embodiment in a side view with a rear engine housed in a casing in a schematic representation, Fig. 8 the motor vehicle in a view according to arrow VIII in Fig. 7, Fig. 9 a motor vehicle according to a fourth embodiment in a view as in Fig. 8.

[0052] In the figures, a vehicle's vertical direction is indicated by an arrow Z, a vehicle's transverse direction is indicated by an arrow Y, and a vehicle's longitudinal direction is indicated by an arrow X.

[0053] The Fig. Figure 1 schematically shows an internal combustion engine 20 of a motor vehicle 10. The internal combustion engine 20 is housed in a casing 40. The casing 40 has an air inlet 41 and an air outlet 42. The casing 40 forms part of an air cooling system for the internal combustion engine 20. In addition to the air cooling system, the motor vehicle 10 has a liquid cooling system for the internal combustion engine 20.

[0054] The air cooling system includes a fan 50, which is configured to draw air into the housing 40 via the air inlet 41 and to expel air from the housing 40 via the air outlet 42. The direction of airflow into and out of the housing 40 is indicated by arrows P1 and P2 in the Fig. 1. The fan 50 is located in the area of ​​the air outlet 42. The fan 50, specifically a fan wheel 51 of the fan 50, is rotationally fixed to a crankshaft of the internal combustion engine 20. The air flowing through the housing 40 flows along the outside of the internal combustion engine 20 and cools it in this way. It is conceivable that the internal combustion engine 20 has one or more cooling fins to improve the heat exchange with the flowing air.

[0055] The liquid cooling system has a coolant circuit with a coolant circulating within that circuit. The coolant circuit is located in the Fig. 1. For the sake of clarity, the internal combustion engine 20 is not shown in detail. The internal combustion engine 20 is integrated into the coolant circuit such that the coolant flows through internal cooling channels of the internal combustion engine 20 and thereby absorbs heat. For example, these cooling channels can be located in a crankcase of the internal combustion engine 20. The cooling channels can form a water jacket around the respective cylinder. The liquid cooling system includes a radiator 31, which is integrated into the coolant circuit to cool the coolant circulating in the circuit. The radiator 31 thus acts as a heat exchanger. The radiator 31 is located in the air inlet 41 of the housing 40, so that the air flowing through the air inlet 41 into the housing 40 flows through the radiator 31.

[0056] How to Fig. As can be seen from Figure 1, this design results in a particularly compact construction for the entire assembly of the combustion engine 20, liquid cooling system, and air cooling system. In particular, the pipe lengths of the liquid cooling system, i.e., the cooling circuit, can be kept especially short, since the radiator 31 can be positioned very close to the combustion engine 20. Despite the radiator 31's proximity to the heat-generating combustion engine 20, the active intake of ambient air through the air inlet 41 ensures sufficient cooling of the coolant circulating in the cooling circuit.

[0057] In addition to the internal combustion engine 20, parts of the exhaust system 60 of the motor vehicle 10 are also housed in the casing 40. This allows parts of the exhaust system 60 to be cooled by the airflow. The exhaust system 60 can, for example, include one or more exhaust manifolds, one or more catalytic converters, and / or one or more rear silencers 61.

[0058] In addition to the single air inlet 41, the housing 40 has a further air inlet 43. This further air inlet 43 is located in the area of ​​the underbody 13 of the motor vehicle 10. This further air inlet 43 is equipped with an air inlet flap 44. This prevents unwanted air from flowing out of or into the housing 40 via the further air inlet 43. The air inlet flap 44 can be designed as a passive air inlet flap 44, in the form of a check valve. However, the air inlet flap 44 can also be actively controlled to move it from an open position to a closed position and vice versa. Fig. Figure 1 shows the air intake flap 44 in the closed position. When the air intake flap 44 is in the open position, air flows into the housing 40 from below the underbody 13 and thus from below the vehicle 10, or is drawn into the housing 40. This airflow is indicated by arrow P3 in the Fig. 1. This allows the contact pressure of the motor vehicle 10 on the road surface to be increased.

[0059] In principle, it is conceivable that a section of the combustion engine 20 and / or the exhaust system 60 forms a side wall of the housing 40, as is the case in the embodiment according to the Fig. 1 is the case.

[0060] The Fig. Figure 2 shows an embodiment of a motor vehicle 10 in which the internal combustion engine 20 and, accordingly, also the housing 40 enclosing the internal combustion engine 20 are formed in a rear area 12 of the motor vehicle 10. In the embodiment shown in the Fig. In the embodiment shown in 2, the internal combustion engine 20 is accordingly a rear engine. In the embodiment shown in the Fig. In the embodiment shown in Figure 2, an additional air inlet 45 is provided, which opens into the surroundings in a side area of ​​the motor vehicle 10, namely in the area of ​​a wheel arch 14 of a rear wheel 15. Furthermore, air guide ribs 16 are provided in the area of ​​the underbody 13 of the motor vehicle 10.

[0061] A guide element 46 in the form of a curved guide plate is arranged in the air outlet 42. This guide element 46 serves to guide the airflow exiting the air outlet 42, wherein the guide element 46 is designed such that the airflow is guided in such a way as to increase the downforce of the motor vehicle 10.

[0062] In the Fig. Figures 3 to 6 show an assembly unit according to a further embodiment, wherein this assembly unit includes, among other things, the housing 40, the internal combustion engine 20, the fan 50, and the radiator 31. In this design, the exhaust system 60 of the internal combustion engine 20 has two rear silencers 61. These rear silencers 61 are separated from each other in the transverse direction Y of the vehicle, with the fan 50 or the fan wheel 51 being arranged between the two rear silencers 61 in the transverse direction Y of the vehicle, as can be seen in particular in the rear view according to the Fig. 4 can be seen.

[0063] The Fig. Figure 7 shows a further embodiment of a motor vehicle 10 according to the invention, wherein this embodiment differs from the embodiment according to the Fig. 2 differs essentially in that the air inlet 41 and the cooler 31 arranged in the air inlet 41 are designed in the area of ​​a rear spoiler 17 of the motor vehicle 10.

[0064] The Fig. Figure 8 shows the motor vehicle 10 according to the Fig. 7 in a rear view. This rear view shows that the motor vehicle 10 is in accordance with the Fig. 7 has a single fan 50.

[0065] The Fig. Figure 9 shows an alternative design in which the motor vehicle 10 has two fans 50 spaced apart in the transverse direction Y of the vehicle. Reference symbol list 10 motor vehicle 12 Rear area 13 Underbody 14 wheel arch 15 rear wheel 16 air guide ribs 17 Rear spoiler 20 internal combustion engine 31 coolers 40 cases 41 Air intake 42 Air outlet 43 additional air intakes 44 Air intake flap 45 additional air intakes 46 Guide element 50 fans 51 Fan wheel 60 Exhaust system 61 Rear silencer P1 Arrow P2 arrow P3 Arrow X Vehicle longitudinal direction Y Vehicle transverse direction Z Vehicle lifting direction

Claims

[1] motor vehicle (10) comprising: - an internal combustion engine (20), - a liquid cooling system for the internal combustion engine (20), wherein the liquid cooling system comprises a coolant circuit with a coolant circulating in the coolant circuit, wherein the internal combustion engine (20) is integrated into the coolant circuit so that liquid cooling of the internal combustion engine (20) is achieved, wherein the liquid cooling system comprises a radiator (31), wherein the radiator (31) is integrated into the coolant circuit for cooling the coolant circulating in the coolant circuit, - an air cooling system for the internal combustion engine (20), wherein the air cooling system comprises a housing (40) with an air inlet (41) and an air outlet (42), wherein the internal combustion engine (20) is housed in the housing (40), wherein the air cooling system comprises a fan (50), wherein the fan (50) is configured to convey air into the housing (40) via the air inlet (41) and out of the housing (40) via the air outlet (42), thus providing air cooling for the internal combustion engine (20), wherein the radiator (31) of the liquid cooling system is arranged in the air inlet (41) of the housing (40), such that the radiator (31) is cooled by the air flowing through the air inlet (41) into the housing (40), characterized by, that the air cooling system is operable in a first operating mode and in a second operating mode, wherein in a first operating mode the air is conveyed into the housing (40) via the air inlet (41) and out of the housing (40) via the air outlet (42), wherein in the second operating mode the air is conveyed into the housing (40) via the air outlet (42) and / or via the further air inlet (43) and out of the housing (40) via the air inlet (42), wherein the motor vehicle (10) has an exhaust system (60), wherein the air outlet (42) is designed such that in the second operating mode at least parts of the gases exiting the exhaust system (60) are drawn into the housing (40) via the air outlet (42). [2] Motor vehicle (10) according to claim 1, wherein the internal combustion engine (20) is arranged in a rear area (12) of the motor vehicle (10). [3] Motor vehicle (10) according to one of the preceding claims, wherein the air inlet (41) and / or the air outlet (42) are formed in the rear area (12) of the motor vehicle (10). [4] Motor vehicle (10) according to one of the preceding claims, wherein the internal combustion engine (20) has a crankshaft, wherein the fan (50), in particular a fan wheel (51) of the fan (50), is coupled to the crankshaft to drive the fan (50). [5] Motor vehicle (10) according to one of the preceding claims, wherein at least parts of the exhaust system (60) are included in the housing (40) so that air cooling of these parts is achieved by the air flowing through the housing (40). [6] Motor vehicle (10) according to one of the preceding claims, wherein the fan (50), in particular the fan wheel (51), is arranged in the area of ​​the air outlet (42). [7] Motor vehicle (10) according to one of the preceding claims, wherein the internal combustion engine (20) has a crankcase, wherein the crankcase has internal cooling channels through which the coolant of the coolant circuit flows, and wherein the air flowing through the housing (40) flows along an outside of the crankcase. [8] Motor vehicle (10) according to one of the preceding claims, wherein the housing (40) has at least one further air inlet (43), wherein this further air inlet (43) opens into the environment in the area of ​​an underbody (13) of the motor vehicle (10), wherein the fan (50) is arranged to draw air into the housing (40) via the further air inlet (43).

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