Internal combustion engine with liquid-cooled cylinder head and cylinder block and method for controlling the cooling of such an internal combustion engine

Abstract

The invention relates to an internal combustion engine (1) with at least one liquid-cooled cylinder head (2) and cylinder block (3), wherein: - the at least one cylinder head (2) is equipped with at least one integrated coolant jacket (2a), - the cylinder block (3) is equipped with at least one integrated coolant jacket (3a), wherein this block-associated coolant jacket (3a) has a second supply opening (4b) on the inlet side for supplying coolant and a second discharge opening (5b) on the outlet side for discharging the coolant, and - to form a coolant circuit, the discharge openings (5a, 5b) are at least connectable to the supply openings (4a, 4b), wherein: - the second discharge opening (5b) is at least connectable to the second supply opening (4b) via a return line (7) in which a heat exchanger (7a) is arranged, - the second discharge opening (5b) is at least connectable to the second supply opening (4b) via a bypass line (8). connectable,- the first discharge opening (5a) via heating circuit line (6), in which a coolant-operated vehicle interior heater (6a) is arranged, is at least connectable to the first supply opening (4a), - upstream of the supply openings (4a, 4b) a common pump (12) is provided for conveying coolant to the two supply openings (4a, 4b), wherein the pump (12) comprises a housing and a shut-off element (9) is provided between the pump (12) and the second supply opening (4b), and - the heating circuit line (6) opens into the bypass line (8), wherein no shut-off element is provided between the first discharge opening (5a) and the bypass line (8).

Description

The invention relates to an internal combustion engine with at least one liquid-cooled cylinder head and one liquid-cooled cylinder block, having the features of the preamble of claim 1. Furthermore, the invention relates to a method for controlling the cooling of such an internal combustion engine. EP 2 309 114 A1 discloses the features of the preamble of claim 1, but relates to an internal combustion engine having a coolant circuit which is divided into a cylinder block-side coolant area and a cylinder head-side coolant area, wherein the cylinder block has at least one cylinder block web, and wherein a cooling slot is arranged in the at least one cylinder web of the cylinder block, wherein a transfer is arranged in the cylinder head, and wherein an outlet is arranged in the cylinder head which is connected to the cylinder head-side coolant area, and wherein the cylinder block-side coolant area is connected via the transfer to the cooling slot which is connected to the outlet, and wherein coolant from the cylinder block-side coolant area can be guided via the transfer into the cooling slot and from there via the outlet into the cylinder head-side coolant area. In order to create a device for cooling an internal combustion engine with a reduced number of components, which is equipped with a coolant circuit having coolant sub-circuits and with an electromechanical assembly and serves to set different operating states of the coolant circuit or the coolant sub-circuits, it is provided according to DE 10 2008 007 766 A1 that coolant sub-circuits separated from each other by the electromechanical assembly can each be switched on their own. An internal combustion engine with a split cooling system is shown in GB 2 245 703 A to enable rapid warm-up. It comprises a radiator, a first pumped coolant circuit for cooling the cylinder head, which includes a bypass line connected in parallel to the radiator, and a second pumped coolant circuit for cooling the engine block. A first thermostat in the first coolant circuit is provided to divert at least some of the water flowing through the cylinder head from the bypass line to the radiator when the coolant in the cylinder head exceeds a predetermined temperature. No connection for coolant flow between the two coolant circuits is provided at the interface between the cylinder head and the engine block.In the second coolant circuit, a second thermostat is provided to prevent the circulation of coolant through the engine block when the temperature of the coolant in the engine block is below a second predetermined temperature, and to connect the return flows from the engine block and the cylinder head above the second predetermined temperature. DE 101 53 586 A1 relates to a system and a method for controlling the cooling of components in a hybrid vehicle. The cooling system has an electric pump to circulate coolant through a closed system containing components of the engine and electric motor. These components can include electric motors, power electronics, and transmissions. The coolant flow to the vehicle engine and electric motor is controlled within a single closed circuit. Vehicle components contain temperature sensors that send temperature signals to a control program for the duty cycle of an electric coolant pump. The control program determines the duty cycle of the electric coolant pump as a function of the temperatures of the vehicle components and directs the electric pump to the appropriate duty cycle.The engine temperature sensors can measure either the engine coolant temperature or the cylinder head temperature. The vehicle components can have multiple coolant flow paths, including parallel and series configurations. The control system can also utilize an averaging filter program, connected between the engine temperature sensor and the control program, to determine the average engine temperature. An internal combustion engine of the type mentioned above is used, for example, as a motor vehicle drive. Within the scope of the present invention, the term internal combustion engine includes diesel engines and gasoline engines, but also hybrid internal combustion engines, i.e., internal combustion engines that can be operated with a hybrid combustion process. In principle, internal combustion engines can be cooled using either air or liquid cooling. Due to the higher heat capacity of liquids, liquid cooling can dissipate significantly larger amounts of heat than air cooling. Therefore, according to current technology, internal combustion engines are increasingly equipped with liquid cooling, as the thermal load on engines is constantly increasing. This is also due to the fact that internal combustion engines are increasingly turbocharged and, with the aim of achieving the densest possible packaging, more and more components are being integrated into the cylinder head or cylinder block, which in turn increases the thermal load on the engines.Increasingly, the exhaust manifold is being integrated into the cylinder head to benefit from the cooling provided in the cylinder head and to avoid having to manufacture the manifold from thermally highly resilient materials, which are expensive. The implementation of a liquid cooling system requires the cylinder head to be equipped with at least one coolant jacket, i.e., coolant channels that carry the coolant through the cylinder head. This coolant jacket is supplied with coolant on the inlet side via an inlet port, and after flowing through the cylinder head, it exits the jacket on the outlet side via an outlet port. Unlike air cooling, where heat needs to be transferred to the cylinder head surface for dissipation, the heat is transferred directly to the coolant within the cylinder head. A pump located within the coolant circuit circulates the coolant. The heat transferred to the coolant is thus removed from the cylinder head via the outlet port and extracted from the coolant outside the cylinder head, for example, by means of a heat exchanger and / or other methods. Like the cylinder head, the cylinder block can also be equipped with one or more coolant jackets. The cylinder head is the component subjected to higher thermal stress because, unlike the cylinder block, it has exhaust gas channels, and the combustion chamber walls integrated into the head are exposed to hot exhaust gases for a longer period than the cylinder tubes in the cylinder block. Furthermore, the cylinder head has a lower component mass than the block. A water-glycol mixture with additives is typically used as the coolant. Water has the advantages over other coolants of being non-toxic, readily available, and inexpensive, and it also has a very high heat capacity, making it suitable for extracting and dissipating very large amounts of heat, which is generally considered advantageous. The internal combustion engine that is the subject of the present invention is liquid-cooled and has at least one liquid-cooled cylinder head and one liquid-cooled cylinder block. To form a coolant circuit, the outlet ports, from which the coolant is discharged, must be at least connectable to the inlet ports, which supply the coolant jackets with coolant. This connection can be achieved using one or more lines. These lines need not be lines in the strict sense, but can also be partially integrated into the cylinder head, cylinder block, or another component. An example of such a line is a return line containing a heat exchanger to extract heat from the coolant. In this context, "at least connectable" means that the outlet ports are either permanently connected to the inlet ports via a piping system or can be selectively connected using valves or shut-off devices. The goal and purpose of liquid cooling is not to extract the greatest possible amount of heat from the internal combustion engine under all operating conditions. Rather, the aim is to control the liquid cooling system according to demand, taking into account not only full load but also the operating modes of the internal combustion engine in which it is more advantageous to extract less heat, or as little as possible, from the engine. To reduce friction and thus fuel consumption in an internal combustion engine, rapid warm-up of the engine oil, especially after a cold start, can be beneficial. Rapid warm-up of the engine oil during the warm-up phase of the internal combustion engine ensures a correspondingly rapid decrease in the oil's viscosity and thus a reduction in friction and frictional power, particularly in the oil-lubricated bearings, such as the crankshaft bearings. Numerous concepts exist in the art for reducing friction by rapidly heating the engine oil. For example, the oil can be actively heated using an external heating device. However, this heating device consumes additional fuel, thus negating any reduction in fuel consumption. Other concepts involve storing the engine oil heated during operation in an insulated container and using it upon restarting the engine. However, the oil heated during operation cannot be stored at a high temperature indefinitely. Another concept repurposes a coolant-operated oil cooler during the warm-up phase to heat the oil, but this again requires rapid heating of the coolant. In principle, rapid heating of the engine oil to reduce friction can also be promoted by rapid heating of the internal combustion engine itself, which in turn is supported, i.e. forced, by ensuring that as little heat as possible is extracted from the internal combustion engine during the warm-up phase. Therefore, the warm-up phase of the internal combustion engine after a cold start is an example of an operating mode in which as little heat as possible, preferably no heat at all, should be extracted from the internal combustion engine. A liquid cooling system that reduces heat loss after a cold start to rapidly warm up the internal combustion engine can be implemented using a self-regulating, temperature-dependent valve, often referred to as a thermostatic valve in the prior art. Such a thermostatic valve has a temperature-sensitive element exposed to coolant, whereby a line running through the valve is either blocked or opened to a greater or lesser extent depending on the coolant temperature at the element. In this way, coolant can be returned, for example, via a bypass line that bypasses a heat exchanger located in a return line, from the outlet side to the inlet side of the cooling circuit. So-called no-flow strategies are also known from the state of the art, in which the coolant flow through the cylinder head or cylinder block is completely prevented in order to extract as little heat as possible from the internal combustion engine. In an internal combustion engine that has both a liquid-cooled cylinder head and a liquid-cooled cylinder block, such as the internal combustion engine that is the subject of the present invention, it would be advantageous to be able to control the coolant flow rate through the cylinder head and the cylinder block independently of each other, especially since the two components are subject to different thermal loads and have different warm-up behavior. The basic aim is to control the liquid cooling system in a way that not only reduces or prevents the amount of coolant circulating or the coolant flow rate after a cold start, but also allows influence on the heat balance of the internal combustion engine in general. For comfort reasons, especially after a cold start, it can be advantageous or desirable to supply a coolant-operated vehicle interior heater with coolant preheated in the cylinder head and / or cylinder block via the heating circuit line. This creates a conflict of objectives: on the one hand, preheating the coolant in the cylinder head or cylinder block to provide the heater with preheated coolant, and on the other hand, preventing or reducing the coolant flow through the cylinder head or cylinder block to minimize heat loss from the internal combustion engine during the warm-up phase. Prior art includes cooling concepts with two separate and therefore independent cooling circuits. These consist of a main coolant circuit, which circulates larger quantities of coolant through at least one coolant jacket integrated into the cylinder block, and a secondary coolant circuit, which circulates smaller quantities of coolant through at least one coolant jacket integrated into the cylinder head. The coolant-operated vehicle interior heater is integrated into the secondary circuit, meaning it is supplied with coolant preheated in the cylinder head via the heater circuit line. Consequently, the coolant flow through the cylinder block can be stopped during the warm-up phase of the internal combustion engine, while the heater continues to be supplied with coolant.While the coolant flow in the main circuit is circulated – as usual – by a mechanically driven water pump, an electrically driven pump is used in the secondary circuit. This additional pump significantly increases the cost and space requirements of the liquid cooling system. Furthermore, the supply of coolant to the vehicle's interior heating system is limited to smaller quantities. Larger quantities of coolant cannot be supplied if required. Against this background, it is an object of the present invention to provide an internal combustion engine according to the preamble of claim 1, the cooling of which is optimized with regard to costs, space requirements and in particular with regard to comfort requirements in connection with a coolant-operated vehicle interior heating system. Another sub-objective of the present invention is to demonstrate a method for controlling the cooling of such an internal combustion engine.The first problem is solved by an internal combustion engine with at least one liquid-cooled cylinder head and a liquid-cooled cylinder block, wherein: - the at least one cylinder head is equipped with at least one integrated coolant jacket, this first coolant jacket having a first supply opening on the intake side for supplying coolant and a first discharge opening on the exhaust side for discharging the coolant; - the cylinder block is equipped with at least one integrated coolant jacket, this block-associated coolant jacket having a second supply opening on the intake side for supplying coolant and a second discharge opening on the exhaust side for discharging the coolant; and - to form a coolant circuit, the discharge openings are at least connectable to the supply openings, wherein - the second discharge opening is connected via a return line in which a heat exchanger is arranged.is at least connectable to the second supply opening, and wherein the second discharge opening is at least connectable to the second supply opening via a bypass line bypassing the heat exchanger arranged in the return line, and wherein the first discharge opening is at least connectable to the first supply opening via a heating circuit line in which a coolant-operated vehicle interior heater is arranged, and wherein a common pump for conveying coolant to the two supply openings is provided upstream of the supply openings, wherein the pump comprises a housing and a shut-off element is provided between the pump and the second supply opening, and which is characterized in that the heating circuit line opens into the bypass line, wherein no shut-off element is provided between the first discharge opening and the bypass line. The internal combustion engine according to the invention has a liquid-cooled cylinder head and a liquid-cooled cylinder block, wherein the at least one coolant jacket integrated in the cylinder head and the at least one coolant jacket integrated in the cylinder block are separated from each other. The first outlet of the first coolant jacket integrated into the cylinder head can be connected to the first supply outlet via the heating circuit line, ensuring that the coolant-operated heater is supplied with coolant preheated in the cylinder head under all operating conditions. This guarantees a minimum supply of heated coolant to the heater. No shut-off element, in particular no thermostatic valve, is provided between the first outlet and the bypass line. If required, the coolant-operated heater can be supplied with coolant preheated in the cylinder head via the heating circuit line, while the coolant flow through the at least one block-specific coolant jacket is stopped by closing the shut-off element located upstream of the second, i.e., block-specific, supply opening. Consequently, the coolant flow through the cylinder block can be stopped during the warm-up phase of the internal combustion engine to minimize heat loss from the engine, while the heater continues to be supplied with coolant. Since both supply ports—that is, both the coolant jacket associated with the head and the coolant jacket associated with the block—are supplied with coolant by a common pump located upstream of the two supply ports, the entire supply of coolant to the coolant-operated heater can be supplied when the second supply port is deactivated by a closed shut-off element. This means that there is no limitation to smaller coolant quantities, as is known from concepts with a secondary circuit. Furthermore, the need for an additional pump, for example, an electrically driven one, is eliminated. The disadvantages associated with such an additional pump, namely the increased costs and space requirements, are thus eliminated. A further advantage arises from the fact that the cylinder head is subjected to a higher thermal load than the cylinder block, meaning that the head heats up faster after a cold start. Consequently, the coolant flow through the cylinder head reaches a higher temperature more quickly than coolant flow through the cylinder block. This translates into a noticeable comfort benefit in terms of rapidly heating the passenger compartment after a cold start. The internal combustion engine according to the invention solves the first problem underlying the invention, namely providing an internal combustion engine whose cooling is optimized with regard to costs, space requirements and in particular with regard to comfort requirements in connection with a coolant-operated vehicle interior heating system. The coolant, routed through the cylinder block, can be returned to the intake side via either a return line or a bypass line after exiting the second outlet. If desired, heat can be extracted from the coolant in a heat exchanger located in the return line. A thermostatic valve positioned downstream of the second outlet can control this coolant flow. The pump ensures that the coolant circulates in the coolant circuits and that heat can be dissipated by convection. Advantageous are internal combustion engine designs in which the pump is variably controllable, allowing the coolant flow rate to be influenced by the delivery pressure. The coolant flowing through the heater or heating circuit is returned to the inlet side via a bypass line, thus bypassing the heat exchanger located in the return line. This approach aligns with the objective of supplying the heater with coolant at the highest possible temperature and with the goal of accelerating the heating of the coolant to speed up the warm-up of the internal combustion engine. Extracting heat from the coolant in the heat exchanger would contradict these objectives. Further advantageous embodiments according to the dependent claims are described in more detail below. In particular, it will become clear how the coolant flows are adjusted and directed, which lines of the circuits are opened or closed, and what effects and benefits advantageously result therefrom. Advantageous are embodiments of the internal combustion engine in which the first coolant jacket integrated in the cylinder head and the block-related coolant jacket are separate from each other. The implementation of the aforementioned features is necessary so that the coolant-operated heating system can be supplied with coolant preheated in the cylinder head via the heating circuit line, while simultaneously the coolant flow through the block-related coolant jacket can be prevented by closing the shut-off element. Advantageous are embodiments of the internal combustion engine in which a coolant-operated cooling device for exhaust gas recirculation is provided in the heating circuit line upstream of the vehicle interior heating. In this way, heat can be extracted from the hot recirculated exhaust gas and additional heat added to the coolant, which is already preheated in the cylinder head. This increases the heating output. If necessary, this reduces the amount of coolant required by the heating system. Advantageous are embodiments of the internal combustion engine in which the second discharge opening provided on the exhaust side for the discharge of the coolant is arranged in the cylinder block. The coolant circuits of the liquid-cooled cylinder head and the liquid-cooled cylinder block, or their respective coolant jackets, are separate from each other. There is no coolant exchange between the at least one cylinder head and the cylinder block. However, embodiments of the internal combustion engine can also be advantageous in which the at least one cylinder head is equipped with at least two integrated and separate coolant jackets, wherein the second coolant jacket is connected to the coolant jacket belonging to the block for supplying coolant and the second discharge opening provided on the exhaust side for discharging the coolant is preferably arranged in the cylinder head. During assembly, the cylinder head and cylinder block are joined together at their mounting end faces, thereby forming the cylinders, i.e., the combustion chambers of the internal combustion engine. In this case, a coolant jacket integrated into the cylinder head, referred to as the second coolant jacket, is supplied with coolant via the engine block. For this purpose, the second coolant jacket is connected to the engine block's own coolant jacket. Advantageously, the second coolant jacket is positioned adjacent to the mounting end face in the cylinder head to simplify the coolant supply via the engine block. This means that the cylinder head is partially permeated by coolant that has already been preheated in the cylinder block, and the coolant heated in the cylinder head is not supplied to the heater via the heating circuit line and used to heat the passenger compartment, but is returned to the intake side via a bypass line or return line. The second discharge opening provided on the outlet side serves in this case to discharge the coolant from the coolant jacket belonging to the block and to discharge the coolant from the second coolant jacket of the cylinder head. Advantageous are embodiments of the internal combustion engine in which the shut-off element is a valve. In particular, the shut-off element is not a thermostatic valve. While thermostatic valves have a characteristic opening temperature, in this case an actively adjustable shut-off element – ​​for example, by means of engine control – is used, preferably a continuously adjustable valve, so that in principle a map-controlled actuation of this shut-off element is possible and thus also a coolant temperature adapted to the current load state of the internal combustion engine, for example a higher coolant temperature at lower loads than at high loads. Different coolant temperatures for different load conditions can be advantageous because heat transfer in a component is not solely determined by the amount of coolant flowing through it, but also significantly by the temperature difference between the component and the coolant. Thus, a higher coolant temperature during partial load operation equates to a smaller temperature difference between the coolant and the cylinder block or cylinder head. The result is lower heat transfer at low and medium loads. This increases efficiency during partial load operation. A shut-off valve controlled by the engine management system allows the coolant flow through the cylinder block, and thus the amount of heat extracted, to be adjusted as needed. Modern internal combustion engines typically have an engine management system, making it advantageous to utilize this system to adjust or control the shut-off valve. Advantageous are internal combustion engine designs in which the housing of the common pump incorporates the shut-off element. This reduces costs, weight, and space requirements. The number of components is reduced, which in turn lowers the supply and installation costs of the cooling system. Advantageous are embodiments of the internal combustion engine in which a second shut-off element is provided between the pump and the first feed opening. This second shut-off element allows the coolant flow through the cylinder head and heater to be adjusted as needed, especially when the first shut-off element is closed. The control and actuation via motor control is again advantageous. Also advantageous are embodiments of the internal combustion engine in which the housing of the common pump accommodates the second shut-off element. The reasons for this are those already mentioned above. Advantageous are embodiments of the internal combustion engine in which the second shut-off element is a valve. This allows for stepless adjustment of the coolant flow rate. In particular, the second shut-off element is not a thermostatic valve. The second sub-problem underlying the invention, namely to demonstrate a method for controlling the cooling of an internal combustion engine of the type described above, is solved by a method characterized in that the shut-off element is closed during the warm-up phase of the internal combustion engine. To accelerate the heating of the internal combustion engine, a no-flow strategy is implemented with respect to the cylinder block during the warm-up phase, i.e., the coolant flow through the cylinder block is completely prevented until predetermined criteria are met that permit or require the opening of the shut-off element. The coolant does not flow but remains stationary within the coolant jacket of the cylinder block. This accelerates the heating of the coolant and the warming of the internal combustion engine. This procedure also promotes the heating of the engine oil, thereby reducing friction and noticeably lowering fuel consumption. What has already been said about the internal combustion engine according to the invention also applies to the method according to the invention. Advantageous are embodiments of the method in which, starting from a closed shut-off element, this shut-off element is opened when a predefinable cylinder block temperature is exceeded. Also advantageous are embodiments of the method in which, starting from a closed shut-off element, this shut-off element is opened when a predefinable coolant temperature is exceeded. In internal combustion engines where a second shut-off element is provided between the pump and the first feed opening, embodiments of the method are advantageous which are characterized in that the coolant flow rate through the first coolant jacket and the heater is controlled by means of this second shut-off element. The adjustment of the first or second shut-off element is preferably carried out depending on a determined cylinder head temperature, cylinder block temperature and / or vehicle interior temperature, or depending on a determined coolant temperature. In this way, both the cylinder head and the cylinder block can be heated or cooled as required, and the vehicle interior can be heated. Advantageous are process variants in which the temperature of the cylinder block or cylinder head is determined by calculation. The temperature is determined computationally, for example, by means of simulation, using models known from the prior art, such as dynamic thermal models and kinetic models for determining the heat of reaction generated during combustion. Preferably, operating parameters of the internal combustion engine, which are already available, i.e., determined in another context, are used as input signals for the simulation. The advantage of simulation is that no additional components, especially no sensors, are required to determine the temperature, which is cost-effective. However, a disadvantage is that the temperatures determined in this way are only estimates, which can reduce the quality of the control system. Method variants in which the temperature of the cylinder block or cylinder head is directly measured using a sensor are also advantageous. Measuring the cylinder block or cylinder head temperature presents no difficulties. Even when the internal combustion engine is warm, the cylinder block or cylinder head maintains relatively moderate temperatures and offers numerous possibilities, i.e., various locations, for placing a sensor without impairing the engine's functionality. To estimate the cylinder head temperature, another component temperature, in particular a cylinder block temperature, can also be used and vice versa, which is measured using a sensor or determined computationally using simulation. In a liquid-cooled internal combustion engine like the one in question, it is also possible to determine, i.e., estimate, the cylinder block temperature or cylinder head temperature using the coolant temperature. The reverse approach is also conceivable. Advantageously, the shut-off element is infinitely adjustable, so that the flow through the cylinder head or through the cylinder block can be adjusted as desired. In principle, the shut-off element can also be designed to be switchable and then switched in stages. During the warm-up phase of the internal combustion engine, while the first shut-off element is closed, the cylinder head can continue to be cooled by coolant, and coolant can be conveyed via the cylinder head and heating circuit line to the coolant-operated heater, so that the heater is supplied with coolant preheated in the cylinder head during the warm-up phase and the passenger compartment is heated. The invention will now be described in more detail with reference to an embodiment according to Fig. 1. Fig. 1 schematically shows a first embodiment of the internal combustion engine. Fig. 1 schematically shows a first embodiment of the liquid-cooled internal combustion engine 1. The internal combustion engine 1 comprises a liquid-cooled cylinder head 2 and a liquid-cooled cylinder block 3 to provide liquid cooling. The liquid-cooled cylinder head 2 has two integrated, separate coolant jackets 2a and 2b. The first integrated coolant jacket 2a has a first inlet opening 4a on the intake side for supplying coolant and a first outlet opening 5a on the exhaust side for discharging coolant. The second integrated coolant jacket 2b is supplied with coolant via the cylinder block 3 (indicated by arrows). For this purpose, the second coolant jacket 2b of the cylinder head 2 is located on the side facing the cylinder block 3 and is connected to a coolant jacket 3a integrated in the block 3, which has a second inlet opening 4b on the intake side for supplying coolant. A second outlet opening 5b is provided on the exhaust side for discharging coolant; this outlet opening is located in the cylinder head 2.The coolant from the block-associated coolant jacket 3a and the coolant from the second coolant jacket 2b integrated in the cylinder head 2 are discharged from this second discharge opening 5b. Upstream of the supply openings 4a, 4b, a common pump 12 is provided for conveying the coolant to the two supply openings 4a, 4b. To form a coolant circuit, the outlet-side discharge openings 5a, 5b can be connected to the inlet-side supply openings 4a, 4b in the manner described below. The second discharge port 5b can be connected to the pump 12 and the supply ports 4a, 4b via the return line 7, in which a heat exchanger 7a is arranged, and / or via the bypass line 8, bypassing the heat exchanger 7a. A thermostatic valve 11 is arranged at the point in the circuit where the bypass line 8 branches off from the return line 7; this valve automatically divides the coolant flow between the two lines 7, 8. The first discharge opening 5a is connectable to the pump 12 and the supply openings 4a and 4b via the heating circuit line 6. The heating circuit line 6, in which a coolant-operated vehicle interior heater 6a is located, opens into the bypass line 8, and no shut-off element is provided between the first discharge opening 5a and the bypass line 8. In this case, a coolant-operated cooling device 6b for exhaust gas recirculation is provided in the heating circuit line 6 upstream of the heater 6a. This device additionally heats the coolant before it is supplied to the heater 6a. A shut-off element 9, in this case a valve 9a, is provided between the pump 12 and the second supply opening 4b. This valve is closed during the warm-up phase of the internal combustion engine 1 to accelerate the heating of the internal combustion engine 1 using a no-flow strategy. The coolant flow through the cylinder block 3 is thereby completely prevented. A second shut-off element 10, in this case also a valve 10a, is provided between the pump 12 and the first supply opening 4a, with which the coolant flow through the cylinder head 2 and the heater 6a is controlled and adjusted. Reference sign 1 Internal combustion engine 2 Cylinder head 2a First coolant jacket of the cylinder head 2b Second coolant jacket of the cylinder head 3 Cylinder block 3a Block-associated coolant jacket 4a First inlet 4b Second inlet 5a First outlet 5b Second outlet 6 Heating circuit line 6a Coolant-operated vehicle interior heater 6b Coolant-operated cooling device 7 Return line 7a Heat exchanger 8 Bypass line 9 Shut-off element 9a Valve 10 Second shut-off element 10a Valve 11 Thermostatic valve 12 Pump

Claims

Internal combustion engine (1) with at least one liquid-cooled cylinder head (2) and a liquid-cooled cylinder block (3), wherein: - the at least one cylinder head (2) is equipped with at least one integrated coolant jacket (2a), this first coolant jacket (2a) having a first supply opening (4a) on the intake side for supplying coolant and a first discharge opening (5a) on the exhaust side for discharging the coolant; - the cylinder block (3) is equipped with at least one integrated coolant jacket (3a), wherein this block-associated coolant jacket (3a) has a second supply opening (4b) on the intake side for supplying coolant and a second discharge opening (5b) on the exhaust side for discharging the coolant; and - to form a coolant circuit, the discharge openings (5a, 5b) are at least connectable to the supply openings (4a, 4b); characterized in that: - the second discharge opening (5b) is connected via return line (7);in which a heat exchanger (7a) is arranged, is at least connectable to the second supply opening (4b),- the second discharge opening (5b) is at least connectable to the second supply opening (4b) via a bypass line (8) bypassing the heat exchanger (7a) arranged in the return line (7),- the first discharge opening (5a) is at least connectable to the first supply opening (4a) via a heating circuit line (6) in which a coolant-operated vehicle interior heater (6a) is arranged,- a common pump (12) for conveying coolant to the two supply openings (4a, 4b) is provided upstream of the supply openings (4a, 4b), wherein the pump (12) comprises a housing and a shut-off element (9) is provided between the pump (12) and the second supply opening (4b), and- the heating circuit line (6) opens into the bypass line (8), where no shut-off element is provided between the first discharge opening (5a) and the bypass line (8). Internal combustion engine (1) according to claim 1, characterized in that the first coolant jacket (2a) integrated in the cylinder head (2) and the coolant jacket (3a) belonging to the block are separated from each other. Internal combustion engine (1) according to one of the preceding claims, characterized in that a coolant-operated cooling device (6b) of an exhaust gas recirculation is provided in the heating circuit line (6) upstream of the vehicle interior heating (6a). Internal combustion engine (1) according to one of the preceding claims, characterized in that the second discharge opening (5b) provided on the exhaust side for discharge of the coolant is arranged in the cylinder block (3). Internal combustion engine (1) according to one of claims 1 to 3, characterized in that the at least one cylinder head (2) is equipped with at least two integrated and separate coolant jackets (2a, 2b), wherein the second coolant jacket (2b) is connected to the block-associated coolant jacket (3a) for the supply of coolant. Internal combustion engine (1) according to claim 5, characterized in that the second discharge opening (5b) provided on the exhaust side for discharge of the coolant is arranged in the cylinder head (2). Internal combustion engine (1) according to one of the preceding claims, characterized in that the shut-off element (9) is a valve (9a). Internal combustion engine (1) according to one of the preceding claims, characterized in that the housing of the common pump (12) accommodates the shut-off element (9). Internal combustion engine (1) according to one of the preceding claims, characterized in that a second shut-off element (10) is provided between the pump (12) and the first feed opening (4a). Internal combustion engine (1) according to claim 9, characterized in that the housing of the common pump (12) accommodates the second shut-off element (10). Internal combustion engine (1) according to claim 9 or 10, characterized in that the second shut-off element (10) is a valve (10a). Method for controlling the cooling of an internal combustion engine (1) according to one of the preceding claims, characterized in that the shut-off element (9) is closed during the warm-up phase of the internal combustion engine (1). Method according to claim 12, characterized in that, starting from a closed shut-off element (9), this shut-off element (9) is opened when a predefinable cylinder block temperature is exceeded. Method according to claim 12, characterized in that, starting from a closed shut-off element (9), this shut-off element (9) is opened when a predefinable coolant temperature is exceeded. Method according to one of claims 12 to 13 for controlling the cooling of an internal combustion engine (1) in which a second shut-off element (10) is provided between the pump (12) and the first supply opening (4a), characterized in that the coolant flow rate through the first coolant jacket (2a) and the heater (6a) is controlled by means of this second shut-off element (9).

Images