EP2876274A1 - Cooling system - Google Patents

Abstract

A cooling system for an internal combustion engine comprising a first cooling circuit comprising a component cooler, an ambient heat exchanger, and a pump (18) and a second cooling circuit comprising a component cooler and a pump (24), the cooling circuits being integrally formed in at least one section and entering the cooling circuits is provided for conveying by the pump (18, 24) provided coolant, characterized in that the pumps are designed controllable and a control of the flowing through the component cooler volume flows of the coolant by means of an adapted operation of the pumps (18, 24).

Description

The invention relates to a cooling system for an internal combustion engine.

Internal combustion engines for motor vehicles have at least one cooling system in which a coolant is pumped by means of one or more pumps in at least one cooling circuit and thereby absorbs heat energy from integrated into the cooling circuit components, in particular the internal combustion engine and an oil cooler and / or a charge air cooler. This thermal energy is then in an ambient heat exchanger, the so-called main water cooler, as well as temporarily in a heating heat exchanger to the ambient air, in the case of the heating heat exchanger to the provided for air conditioning of the interior of the motor vehicle ambient air delivered.

Cooling systems of modern motor vehicles generally have several cooling circuits. For example, it is known to provide a so-called large or main cooling circuit and a small cooling circuit, which are partially formed integrally, and wherein by means of a thermostatically controlled valve, the coolant is guided either over the large or the small cooling circuit. This takes place as a function of the temperature of the coolant, so that, for example, in a warm-up phase of the internal combustion engine, when the coolant has not yet reached its operating temperature range, this is conveyed in the small cooling circuit, whereby the main water cooler, ie that ambient heat exchanger in which the coolant through Heat transfer to the ambient air is mainly cooled, is bypassed. On the other hand, if the coolant has reached its operating temperature range, the coolant in the large customer group is conveyed by means of the thermostat-controlled valve, so that overheating of the cooling system is avoided by a heat transfer from the coolant to the ambient air. By contrast, the heating heat exchanger as the second ambient heat exchanger is regularly integrated into the small cooling circuit, which enables the interior of the motor vehicle to be heated even in the warm-up phase of the internal combustion engine.

The (main) pump of the cooling system is regularly mechanically driven by the internal combustion engine of the internal combustion engine. Their delivery rate is thus basically proportional to the speed at which a crankshaft of the internal combustion engine rotates. Although with increasing speed of the internal combustion engine also the cooling power demand tends to increase, the theoretically achievable by the operation of the pump cooling performance in many operating conditions does not correspond to the actual cooling power requirement. Since a sufficiently high cooling capacity should be available in all operating states, such mechanically driven pumps are often oversized. Attempts to reduce the fuel requirements of motor vehicles have therefore led to the development of mechanically driven coolant pumps which are adjustable in terms of the volume flow rate. Such a controllable, mechanically driven coolant pump is for example from the DE 10 2010 044 167 A1 known.

In the cooling systems of modern motor vehicles, the main control of the volumetric flow of the coolant thus takes place by means of controllable coolant pumps while the distribution of the volumetric flow is controlled to the individual, each having a different cooling demand component cooler by means of active and in particular controlled by thermostats valves. For example, the DE 103 42 935 A1 an internal combustion engine with a cooling circuit comprising a mechanically driven by an internal combustion engine pump. The delivery volume flow of the pump is thus dependent on the speed of the internal combustion engine. In order to achieve individually adapted volumetric flows of the coolant for a plurality of heat exchangers integrated in the cooling circuit, in particular cooling ducts of a cylinder crankcase and a cylinder head of the internal combustion engine and a heating heat exchanger for an interior heating of a motor vehicle driven by the internal combustion engine, a plurality of individually controllable control valves are provided in the Integrated cooling circuit. The DE 103 42 935 A1 further discloses that the passages of the cylinder crankcase and the cylinder head are connected in parallel, thereby making it possible to individually control the cooling capacity for these components. That from the DE 103 42 935 A1 known cooling system is relatively expensive.

From the DE 199 06 523 A1 In addition, a cooling system for a motor vehicle is known which comprises two cooling circuits, namely a main cooling circuit comprising the main water cooler, a main coolant pump and cooling channels of an internal combustion engine and a secondary cooling circuit comprising a heating heat exchanger for an interior heating of the motor vehicle. The additional auxiliary heating device and a separate, electrically operated pump having secondary cooling circuit is designed as a short circuit, ie by means of an actively controllable valve, the auxiliary cooling circuit is operable independently of the main cooling circuit.

For a good and especially efficient cooling performance of a cooling circuit, it is relevant that this is vented as completely as possible. Accordingly, during the filling process of the cooling circuit, in particular during initial filling or refilling as part of maintenance, the air contained in the cooling circuit, which is displaced by the inflowing coolant, must be removed as completely as possible. In addition, during operation of the motor vehicle and thus of the cooling circuit, gas can be produced by evaporation processes, which should be safely dissipated. This is especially true if the cooling circuit is designed for an operating temperature of the coolant, which is above the (pressure-dependent) boiling point of water. Water that has accumulated or settled in the cooling circuit, then evaporates and should be discharged accordingly.

A ventilation of a cooling circuit is carried out regularly via a surge tank of the cooling system. Such a reservoir also has the task of compensating for the different thermal expansion of the coolant and is partially filled with air. For venting can lead a vent line of usually the highest point of the cooling circuit to the even higher arranged surge tank.

Based on this prior art, the present invention seeks to provide a simple as possible adjustable cooling system for a motor vehicle.

This object is achieved by a cooling system according to independent claim 1. A method for operating such a cooling system is the subject of claim 11. The subject of claim 15 is also a connection element that can be advantageously used to form the cooling system according to the invention. Advantageous embodiments and embodiments of the cooling system according to the invention and the method according to the invention are the subject of the further claims and will become apparent from the following description of the invention.

The invention is based on the idea to obtain as simple as possible all temperature-controlled valves as simple as possible cooling system. In this case, an underlying realization of the invention is that by a suitable integration of at least two controllable coolant pumps without such temperature-controlled valves an individual control of the individual Component cooler flowing volume flow of the coolant and thus the cooling power requirement for these component cooler can be done. It is important that the at least two controllable pumps are integrated into different cooling circuits, which are partially formed integrally, so that by the mutual influence or superposition of the volume flow generated by the individual coolant pumps or pressure of the coolant an individual control of the individual Component cooler flowing volume flow can be done.

Accordingly, a cooling system for an internal combustion engine having a first cooling circuit comprising a component cooler, an ambient heat exchanger and a pump and a second cooling circuit comprising a component cooler and a pump, wherein the cooling circuits are integrally formed in at least a portion and provided in the cooling circuits a coolant for delivery is or is promoted according to the invention, characterized in that the pumps are designed to be controllable and a control of the flowing through the component cooler volume flows of the coolant by means of (mutually) adapted operation of the at least two pumps can take place or takes place.

The term "cooler" according to the invention heat exchangers understood that a heat transfer in both directions, i. from a component to the coolant and from the coolant to the component. The term "radiator" is chosen because during normal operation of the internal combustion engine, i. when this has reached its operating temperature range, a heat transfer from the component to the coolant is provided and the heat exchanger causes a cooling of the components. In another operating phase of the internal combustion engine, in particular in a warm-up phase or during operation with very low power, however, a heat transfer from the coolant to the respective component can be provided. As a result, in particular a rapid heating of the component can be achieved.

In a preferred embodiment of the cooling system according to the invention can be provided that the at least two pumps are driven by an electric motor. This allows a particularly simple and accurate control of the individual pumps and thus also the adapted operation of the at least two pumps. It is also possible, one, several or all of the pumps mechanically run by, for example, an internal combustion engine of the internal combustion engine, the controllability of the flow rates these pumps by other measures (see, for example DE 10 2010 044 167 A1 ) can be achieved.

In a cooling system according to the invention can advantageously be provided that in a warm-up phase of the internal combustion engine mainly or exclusively the pump of the second cooling circuit is operated, while the pump of the first cooling circuit is not operated or only with low power. The then a significant throttling effect having pump of the first cooling circuit largely prevents that a relevant volume flow of the coolant through the ambient heat exchanger, which may in particular be the so-called main water cooler, is performed. As a result, such an undesired cooling of the coolant in the ambient heat exchanger during the warm-up phase of the internal combustion engine can be prevented and a rapid heating of the coolant can be supported.

In particular, when the throttling action of a low power or not operated pump is not sufficient to prevent flow through the associated cooling circuit sufficiently, in a preferred embodiment of the cooling system according to the invention means for preventing backflow of the coolant from the integral Section be provided in one or both cooling circuits. These means can be designed, for example, in the form of check valves integrated into the cooling circuit (s). If the means are integrated directly into a mouth portion of the integral portion, there is also the advantageous possibility to form them in the form of a flap valve that is pressure-dependent pivotable and thereby either the orifice of the first or the second cooling circuit (at least partially) closes.

It can preferably be provided that a heating heat exchanger is integrated in the second cooling circuit of the cooling system. Thus, it can be ensured that, if necessary, during the warm-up phase of the internal combustion engine, heat energy can be transferred from the cooling circuit to ambient air provided for conditioning an interior of the motor vehicle.

The warm-up phase of the internal combustion engine may further preferably in a first phase in which the pump of the second cooling circuit with a relatively low flow rate and thus a correspondingly low flow rate of the coolant is operated, and a second phase in which the pump of the second cooling circuit with a relative high flow rate and thus a correspondingly high volume flow of the coolant is operated, be divided. As a result, it can be achieved, for example, that in the first phase, which is preferably prior to the second phase, rapid heating of this component is achieved by only a very small flow of, in particular, an internal combustion engine and particularly preferably a cylinder head of the internal combustion engine, which is positive can affect the fuel consumption and the exhaust emissions of the internal combustion engine. In this case, the regulation of the delivery rate of the pump of the second cooling circuit can in particular also be effected as a function of an ambient temperature and a setpoint temperature for the interior of the motor vehicle. If a heating power for the interior is provided depending on the difference between the ambient temperature and the target temperature for the interior, the pump of the second cooling circuit can be operated at a higher power in said first phase of the warm-up phase, as is the case no heating power is necessary.

The second phase of the warm-up phase with a different, relatively higher flow rate of the pump of the second cooling circuit and thus a higher volume flow of the coolant through the second cooling circuit can be started in particular when (initially) sufficient heating of the internal combustion engine and in particular of the cylinder head has been achieved and / or no particularly high heating power for the interior of the motor vehicle is required more. Then, the heat energy absorbed by the coolant in the internal combustion engine may preferably be utilized for rapid heating of another component, such as the engine oil. For this purpose, a corresponding further component cooler, in particular an engine oil cooler, can be integrated into a connecting section connecting the two cooling circuits. In this case, the integration of the connection section preferably takes place in such a way that the coolant flowing over the further component cooler can circulate, without being led over the ambient heat exchanger of the first cooling circuit.

If the cooling system according to the invention, as usual in the prior art, has a surge tank, it can preferably be provided that this is integrated into a section in which no relevant volume flow of the coolant is provided in the warm-up phase of the internal combustion engine. In particular, the expansion tank can be integrated into the first cooling circuit parallel to the ambient heat exchanger. This can avoid that during the warm-up phase, the coolant to be heated as quickly as possible is conveyed through the surge tank to a relevant extent, which otherwise may be associated with a not inconsiderable, in this phase of the engine undesirable cooling of the coolant.

The inventive design of the cooling system has in such a positioning of the surge tank still has the advantage of easy feasible ventilation of the cooling system in a new or refill. In particular, it may be provided that during or after the filling of the cooling circuit with the coolant, the pump (not of the internal combustion engine and in particular electrically driven) of the first cooling circuit is operated without the internal combustion engine of the internal combustion engine being operated (non-operation of the internal combustion engine). This simplifies the filling process. On the other hand, in internal combustion engines with conventional cooling systems, the internal combustion engine usually has to be operated for venting after refilling or refilling the cooling system in order to operate the (main) pump of the cooling system, through which then the coolant and coolant contained in the cooling system Air is conveyed in the direction of the expansion tank.

In a further preferred embodiment of the cooling system according to the invention can be provided that a first of the component cooler is arranged in the integral portion of the two cooling circuits. In this case, the first component cooler particularly preferably comprises a first part-component cooler and a second part-component cooler, wherein the part-component coolers are connected in parallel. In particular, the first part-component radiator may be a cooler of a cylinder crankcase (in particular in the form of cooling channels integrated in the cylinder crankcase) and the second part-component radiator may be a cooler of a cylinder head (in particular in the form of cooling channels integrated in the cylinder head) of an internal combustion engine Internal combustion engine act.

It can be particularly preferably provided that the volume flow of the coolant through the first Teilkomponentenkühler by means of a pressure-controlled valve in dependence on the volume flow through the second Teilkomponentenkühler is controllable. Thus, it can be provided, in particular, that a relevant flow through the radiator of the cylinder crankcase with the coolant takes place only when the flow through the radiator of the cylinder head has exceeded a defined limit value.

By means of such a cooling system, a preferred embodiment of the method according to the invention can be realized in which the delivery rate of the pump of first cooling circuit based on the temperature of the coolant at the outlet of the second Teilkühlkomponente (for which the or the cooling circuits have at least one appropriately arranged temperature sensor) is controlled and a volume flow through the first Teilkomponentenkühler is controlled by means of a matched operation of the pump of the second cooling circuit. Thus, it may be provided that the temperature of the cylinder head, which is reflected in the temperature of the coolant at the outlet of the radiator of the cylinder head, is used as one or the relevant controlled variable for the pump of the first cooling circuit, wherein a control of the cooling performance of the radiator of the cylinder head and thus the temperature of the cylinder head can be advantageously controlled by the flow rate of this pump. To decouple this regulation of the control of the cooling capacity of the radiator of the cylinder crankcase, then the pressure in the integral portion of the cooling circuits can be varied by means of the pump of the second cooling circuit that the pressure-controlled valves opens or closes in a defined extent and thus the flow through the Radiator of the cylinder crankcase regulates.

An advantageously usable for the formation of such a cooling circuit connection element which can be connected in particular to the outside of an internal combustion engine of the internal combustion engine, has at least one two separate flow chambers forming (one or more parts) housing, wherein a first of the flow spaces with at least two inlet ports, both (in particular alternatively) can be shut off by means of a device for preventing backflow, and is connected to an outlet port. On the other hand, a second of the flow spaces is connected to at least two inlet connections, one of which can be shut off by means of a pressure-actuated shut-off element, and at least two outlet connections.

In such a connection element, a temperature sensor can furthermore preferably be arranged in (or at least in the vicinity of) at least one of the two inlet connections connected to the second flow space. This may in particular be that inlet connection which connects a cooling channel of the cylinder head of the internal combustion engine with the second flow chamber.

The indefinite articles ("an", "an", "an" and "an"), in particular in the patent claims and in the specification generally explaining the claims, are to be understood as such and not as numerical words to understand that these are present at least once and may be present more than once.

Fig. 1:

eine Brennkraftmaschine mit einem erfindungsgemäßen Kühlsystem in einer schematischen Darstellung ;

Fig. 2:

eine bauliche Umsetzung eines Teils des Kühlsystems der Fig. 1 in einer perspektivischen Ansicht;

Fig. 3:

in isolierter Darstellung das Anschlusselement des Kühlsystems gemäß der Fig. 2;

Fig. 4:

eine Prinzipdarstellung eines ersten Strömungsraums des Anschlusselements gemäß der Fig. 3;

Fig. 5:

eine Prinzipdarstellung eines zweiten Strömungsraums des Anschlusselements gemäß der Fig. 3;

Fig. 6:

die Durchströmung eines Teils des Kühlsystems gemäß der Fig. 1 in einem ersten Betriebszustand der betriebswarmen Brennkraftmaschine;

Fig. 7:

die Durchströmung eines Teils des Kühlsystems gemäß der Fig. 1 in einem zweiten Betriebszustand der betriebswarmen Brennkraftmaschine;

Fig. 8:

die Durchströmung des Kühlsystems gemäß der Fig. 1 in dem ersten und zweiten Betriebszustand der betriebswarmen Brennkraftmaschine;

Fig. 9:

eine nicht erfolgende Durchströmung des Kühlsystems gemäß der Fig. 1 in einer ersten Phase einer Warmlaufphase der Brennkraftmaschine;

Fig. 10:

die Durchströmung des Kühlsystems gemäß der Fig. 1 in einer zweiten Phase der Warmlaufphase der Brennkraftmaschine; und

Fig. 11:

die Durchströmung des Kühlsystems gemäß der Fig. 1 in einer dritten Phase der Warmlaufphase der Brennkraftmaschine.

The present invention will be explained in more detail with reference to embodiments shown in the drawings. In the drawings, each schematically shows:

Fig. 1:

an internal combustion engine with a cooling system according to the invention in a schematic representation;

Fig. 2:

a structural implementation of a part of the cooling system of Fig. 1 in a perspective view;

3:

in isolation, the connection element of the cooling system according to the Fig. 2 ;

4:

a schematic representation of a first flow space of the connecting element according to the Fig. 3 ;

Fig. 5:

a schematic representation of a second flow space of the connecting element according to the Fig. 3 ;

Fig. 6:

the flow through a part of the cooling system according to the Fig. 1 in a first operating state of the warm-running internal combustion engine;

Fig. 7:

the flow through a part of the cooling system according to the Fig. 1 in a second operating state of the warm operating internal combustion engine;

Fig. 8:

the flow through the cooling system according to the Fig. 1 in the first and second operating states of the warm operating internal combustion engine;

Fig. 9:

a non-passing through the cooling system according to the Fig. 1 in a first phase of a warm-up phase of the internal combustion engine;

Fig. 10:

the flow through the cooling system according to the Fig. 1 in a second phase of the warm-up phase of the internal combustion engine; and

Fig. 11:

the flow through the cooling system according to the Fig. 1 in a third phase of the warm-up phase of the internal combustion engine.

The Fig. 1 shows an internal combustion engine with a cooling system according to the invention, wherein in addition to the cooling system, an internal combustion engine 10 of the internal combustion engine is shown. The internal combustion engine 10 may be embodied as a conventional reciprocating internal combustion engine and then comprises a cylinder crankcase 12 in which a plurality of cylinders (not shown) are formed, in each of which a piston (not shown) is movably guided. A cylinder head 14 closes the cylinder crankcase 12 and thus the cylinders upwards and further comprises at least one inlet and at least one exhaust valve for each of the cylinders, by which a gas exchange in combustion chambers formed by the cylinders and the pistons is controlled in a known manner.

Both the cylinder crankcase 12 and the cylinder head 14 are cooled by means of the cooling system, to which these cooling channels 58, 60 have, which are filled with the coolant of the cooling system and flows through this at least temporarily. The (at least one) cooling passage 60 of the cylinder crankcase 12 and the (at least one) cooling passage 58 of the cylinder head 14 are formed parallel and thus are also parallel to the coolant flows through.

The cooling system forms a first cooling circuit and a second cooling circuit, which are formed integrally in a section, specifically in the section formed by the cooling channels 58, 60 of the internal combustion engine 10. Accordingly, during operation of the cooling system, the cooling channels 58, 60 of the internal combustion engine 10 at least partially flows through, regardless of whether only the first or the second or both cooling circuits are used.

The first cooling circuit further comprises an ambient heat exchanger, which is provided as a so-called main water cooler 16, and a first, electrically driven and controllable in terms of their capacity pump 18, which is arranged downstream of the main water cooler 16. Furthermore, a surge tank 20 is provided, which is integrated in a parallel connection to the main water cooler 16 in the first cooling circuit. The individual components of the first cooling circuit are fluid-conductively connected via corresponding connection lines.

The second cooling circuit also comprises a heating heat exchanger 22, which also represents an ambient heat exchanger, with this if necessary, a heat transfer from the coolant to ambient air, for the air conditioning of an interior of the one of the Internal combustion engine driven motor vehicle is provided, can take place. Furthermore, the second cooling circuit comprises a second, electrically driven and with regard to their delivery rate controllable pump 24, which is arranged downstream of the heating heat exchanger 22. The individual components of the second cooling circuit are fluid-conductively connected via corresponding connecting lines

The cooling system further comprises an intermediate cooling circuit formed by the integral portion of the first and second cooling circuits, another section of the first cooling circuit, another section of the second cooling circuit, and a connecting section (with corresponding connection lines) connecting the first cooling circuit and the second cooling circuit , In this case, based on the flow direction of the coolant, the connecting portion downstream of the internal combustion engine 10 and upstream of the main water cooler 16 and the surge tank 20 from the first cooling circuit. The mouth of the connecting portion is integrated downstream of the heat exchanger 22 and upstream of the pump 24 (and thus also upstream of the engine 10) in the second cooling circuit. In the connecting portion of the intermediate cooling circuit, a further component cooler in the form of a motor oil cooler 26 is integrated. The engine oil cooler 26 is used in the operation of the internal combustion engine after reaching the operating temperature range cooling the used for lubricating the engine 10 engine oil.

To form the integral portion of the first and second cooling circuits, a connection element 28 is provided, which in the Fig. 3 shown in isolation. From a housing 30 of the connecting element 28, which is provided for a lateral flanging to the internal combustion engine 10, a first flow space 32 and a second flow space 34, which are separated from each other, are formed.

As is clear from the 4 and 5 results, the first flow space 32 with two inlet ports 36, 38 is connected, of which a first, the inlet port 36, serves as a supply of coolant from the first cooling circuit and the second, the inlet port 38, as a supply of coolant from the second cooling circuit. An outlet port 40 connected to the first flow space 32 is connected to a cooling passage 62 of the engine 10. This cooling channel 62 of the internal combustion engine 10 is provided upstream of a branch 64, which serves for a division of the coolant to the parallel cooling channels 58, 60 of the cylinder crankcase 12 and the cylinder head 14. Within the first flow space 32, a valve flap 42 is further provided, which depends on the pressure difference of the first cooling circuit and the second Cooling circuit in the first flow chamber 32 entering coolant in the direction of one or the other inlet port 36, 38 is pivoted.

In the Fig. 1 and 6 to 11 is shown that instead of the valve flap 42, two check valves 44 can be used, of which one of the two inlet ports 36, 38 is assigned.

The second flow space 34 is also fluid-conductively connected to two inlet ports 46, 48, wherein a first, the inlet port 46, fluidly connected to the cooling channel 28 of the cylinder crankcase 12 and the second, the inlet port 48, fluidly connected to the cooling channel 58 of the cylinder head 14. In this case, the inlet connection 46 connected to the cooling passage 60 of the cylinder crankcase 12 can be closed by means of a pressure-actuated valve 50. The valve 50 comprises a valve body, which is acted upon by means of a prestressed spring element in the direction of an orifice opening of this inlet connection 46. Furthermore, the second flow space 34 is fluidly connected to three outlet ports 52, 54, 56, of which a first, the outlet port 52, the discharge of coolant from the second flow space 34 in the first cooling circuit, a second, the outlet port 54, for discharging Coolant from the second flow space 34 in the second cooling circuit and the third, the outlet port 56, for discharging coolant in the engine oil cooler 26 comprehensive connecting portion of the intermediate cooling circuit is used.

The cooling system shown in the drawings works completely without temperature-controlled valves. A regulation of the volume flows of the coolant conducted via the individual component coolers and heat exchangers, and thus the corresponding cooling or heat exchange rates, is achieved exclusively via adapted power control of the two pumps 18, 24.

The 6 and 7 show ways to control the cooling capacity of the cylinder crankcase 12 and the cylinder head 14 by flowing through the flow rates of the coolant. The pressure-actuated valve 50 in the second flow space 34 of the connection element 28 opens the inlet connection 46 connected to the cooling channel 60 of the cylinder crankcase 12, for example, only at a pressure difference of approximately 200 mbar. Such an overpressure in the cooling passage 60 of the cylinder crankcase 12 can be achieved, for example, when the volume flow of the coolant through the cooling passage 58 of the cylinder head 14 is at least 15 l / min. In the Fig. 6 For example, it is shown that such a flow through the cooling channel 58 of the cylinder head 14 of Up to 15 l / min can be achieved by a combined operation of both pumps 18, 24. It can be provided in particular that the greater proportion of the volume flow is achieved by the delivery rate of the pump 18 of the first cooling circuit. However, it may also be possible to achieve the entire volume flow of the coolant through the cooling channel 58 of the cylinder head 14 exclusively by the operation of one of the two pumps 18, 24. On the other hand, if a volume flow through the cooling channel 58 of the cylinder head 14 of 15 l / min is exceeded, the pressure-actuated valve 50 opens and thus enables the coolant channel 60 of the cylinder crankcase 12 to be flowed through by the coolant. This volume flow of the coolant through the cooling passage 60 of the cylinder crankcase 12 can be smaller than the volume flow of the coolant through the cooling passage 58 of the cylinder head 14, in particular Fig. 7 is shown that the entire volume flow is generated by the internal combustion engine 10 in about half of each of the two pumps. Any other division is possible by a corresponding control of the pumps 18, 24.

In particular, it may be provided to effect a control of the pump 18 of the first cooling circuit as a function of the temperature of the coolant emerging from the cooling passage 58 of the cylinder head 14. For this purpose, a temperature sensor (not shown) is integrated in the inlet connection 48 of the connection element 28 connected to the cooling channel 58 of the cylinder head 14. Its measuring signal can be transmitted to a control device (not shown), for example a central engine control of the internal combustion engine, which activates the pump 18 of the first cooling circuit as a function of this measuring signal. The delivery rate of the pump 18 of the first cooling circuit can thus be continuously adjusted such that the coolant leaving the cooling channel 58 of the cylinder head 14 and thus also the cylinder head 14 itself is within a defined operating temperature range. Whether at the same time the cylinder crankcase 12 - and if so, with what volume flow - is flowed through by the coolant and thus a cooling of the cylinder crankcase 12 should be, then, for example, exclusively by means of a corresponding, the control of the pump 18 of the first cooling circuit superimposed control of the pump 24 of the second cooling circuit. For this purpose, a temperature sensor (not shown) may be provided in the inlet port 46 of the connecting element 28 connected to the cooling channel 60 of the cylinder crankcase 12, the measuring signal of which is transmitted to a control device (not shown), in particular the engine control of the internal combustion engine, which then activates a corresponding control the pump 24 of the second cooling circuit makes.

Such an operation of the cooling system makes sense in particular after reaching a defined, intended for continuous operation operating temperature range of the internal combustion engine. The Fig. 8 clarifies once again the then taking place flow through the first and the second cooling circuit and the intermediate cooling circuit.

A regulation of the cooling capacity of the engine oil cooler 26 and thus the temperature of the engine oil during operation of the internal combustion engine in its operating temperature range can be achieved due to the selected configuration of the intermediate cooling circuit in particular by a corresponding control of the pump 24 of the second cooling circuit. For example, for the operation of the internal combustion engine in its operating temperature range, boundary volume flows for the flow through the engine oil cooler 26 of 1.5 l / min and 8 l / min can be provided.

An operation of the cooling system, in which the first and the second cooling circuit and the intermediate cooling circuit are flowed through by the coolant, can also be used for venting after a new or refilling of the cooling system, which may be done for example in the context of the new production or maintenance of the internal combustion engine , be used. By the circulation of the coolant, air that is still within the cooling system, taken and gradually promoted to the surge tank 20 in which it is separated from the coolant. Since both pumps 18, 24 of the cooling system are electrically driven and regulated, the recirculation of the coolant in the cooling system can also take place without an operation of the internal combustion engine 10.

The Fig. 9 to 11 In contrast, show an operation of the cooling system in a warm-up phase of the internal combustion engine, ie in one operation (especially after a cold start) with not yet reached operating temperature range. It is provided that then either no or only the pump 24 of the second cooling circuit is operated. This results in a cooling medium resting in the cooling system or a circulation of coolant in the second cooling circuit and in the intermediate cooling circuit, but not in the first cooling circuit. The non-operation of the pump 18 of the first cooling circuit in conjunction with the resulting closure of the first cooling circuit with the first flow chamber 32 of the connecting element 28 connecting inlet port 36 through the valve flap 42 (or the corresponding check valve 44) prevents in an operation of the pump 24 of the second cooling circuit effectively a flow through the main water cooler 16 and the surge tank 20 and thus an undesirable during the warm-up phase cooling of the coolant through these components.

The warm-up phase is divided into at least two, preferably three phases. In a first phase directly following the cold start (cf. Fig. 9 ) may be provided to operate none of the pumps 18, 24, whereby the coolant in the entire cooling system largely rests. As a result, particularly rapid heating of the cylinder head 14 and also of the cylinder crankcase 12 can be achieved by the waste heat of the combustion processes taking place in the combustion chambers of the internal combustion engine 10.

Shortly afterwards, in a second phase (cf. Fig. 10 ), the pump 24 of the second cooling circuit with a relatively low flow rate are put into operation. As a result, a small volume flow of the coolant is to be achieved by the cylinder head 14, whereby local overheating of the cylinder head 14 can be avoided. A volume flow of the coolant through the cylinder crankcase 12 is not provided in this phase.

As soon as a defined minimum limit temperature has been reached for the cylinder head 14, which can be determined by measuring the temperature of the coolant emerging from the cooling passages of the cylinder head 14, the third phase (cf. Fig. 11 ) of the warm-up phase are introduced, which differs from the second phase by a higher capacity of the pump 24 of the second cooling circuit. In this phase can be provided in particular, after reaching the minimum limit temperature for the cylinder head 14 to achieve a defined operating temperature range for the engine oil as quickly as possible. For this purpose, with the then in comparison to the second phase then larger volume flow of the coolant increasingly heat energy, which receives the coolant in the cylinder head 14, discharged in the engine oil cooler 26 to the engine oil. Also in this phase can be provided that no flow through the cylinder crankcase 12 takes place with the coolant.

An operation of the cooling system according to this third phase may also be provided after reaching the operating temperature range of the internal combustion engine, when the internal combustion engine 10 is operated over a longer period of very low power. As a result, an excessive drop in the temperature of the engine oil can be prevented.

Furthermore, it can also be provided that heat energy stored in a heat accumulator, not shown in the drawings, which is integrated in the cooling system and in particular in the second cooling circuit and / or the intermediate cooling circuit (and which, for example, in or shortly after a previous operation of the internal combustion engine) the heat storage was stored), is discharged to the coolant. To get a distribution of this before stored thermal energy in the second cooling circuit and the intermediate cooling circuit to achieve, it may preferably be provided that such a discharge of the heat accumulator is combined with an operation of the pump 24 of the second cooling circuit with at least relatively low flow rate. Thus, it can be provided in particular to integrate a discharge of a heat accumulator in the previously described second phase of the warm-up phase. If appropriate, the first phase described above can then be dispensed with, whereby the second phase with the discharge of the heat accumulator would become the first phase of the warm-up phase.

If such a heat accumulator is integrated in the cooling system and in particular in the second cooling circuit and / or the intermediate cooling circuit, it may be provided, after the end of the operation of the internal combustion engine (especially if this had reached its operating temperature range during operation), the pumps 18, 24 and in particular, to let the pump 24 of the second cooling circuit still run for a defined period of time. This makes it possible to transfer the heat energy remaining in the coolant and in the operation of the internal combustion engine cooled by the coolant components as much as possible to the heat storage in order to recharge it.

In addition to the component coolers shown and described, the cooling system may include other component coolers. This may be, for example, a transmission oil cooler, a cooler for an exhaust gas turbocharger, a charge air cooler and / or a cooler for exhaust gas recirculation.

LIST OF REFERENCE NUMBERS

10

internal combustion engine

12

cylinder crankcase

14

cylinder head

16

Main water cooler

18

Pump of the first cooling circuit

20

surge tank

22

Heater core

24

Pump of the second cooling circuit

26

Engine oil cooler

28

connecting element

30

casing

32

first flow space of the connection element

34

second flow space of the connection element

36

first outlet port of the first flow space

38

second outlet port of the first flow space

40

Inlet port of the first flow space

42

valve flap

44

check valves

46

first inlet port of the second flow space

48

second inlet port of the second flow space

50

Valve

52

first outlet port of the second flow space

54

second outlet port of the second flow space

56

third outlet port of the second flow space

58

Cooling channel of the cylinder head

60

Cooling channel of the cylinder crankcase

62

Cooling channel of the internal combustion engine

64

branch

Claims (15)

A cooling system for an internal combustion engine comprising a first cooling circuit comprising a component cooler, an ambient heat exchanger and a pump (18) and a second cooling circuit comprising a component cooler and a pump (24), the cooling circuits being integrally formed in at least one section and being incorporated in the cooling circuits Promotion by the pump (18, 24) provided coolant is provided, characterized in that the pumps are designed controllable and a control of the flowing through the component or the component flow rates of the coolant by means of an adapted operation of the pumps (18, 24). Cooling system according to claim 1, characterized in that the pumps (18, 24) are driven by an electric motor. Cooling system according to claim 1 or 2, characterized in that a component cooler is arranged in the integral section of the cooling circuits. Cooling system according to claim 3, characterized in that the component cooler comprises a first Teilkomponentenkühler and a second Teilkomponentenkühler, which are connected in parallel. Cooling system according to claim 4, characterized in that the volume flow through the first Teilkomponentenkühler by means of a pressure-controlled valve (50) in dependence on the volume flow through the second Teilkomponentenkühler is controllable. Cooling system according to claim 4 or 5, characterized in that the first Teilkomponentenkühler a cooler of a cylinder crankcase (12) and the second Teilkomponentenkühler comprises a radiator of a cylinder head (14) of an internal combustion engine (10) of the internal combustion engine. Cooling system according to one of the preceding claims, characterized by means for preventing backflow of the coolant from the integral section into the cooling circuits. Cooling system according to one of the preceding claims, characterized by a heating heat exchanger (22) integrated in the second cooling circuit. Cooling system according to one of the preceding claims, characterized by a connecting portion connecting the cooling circuits with a component cooler. Cooling system according to one of the preceding claims, characterized by an expansion tank (20) integrated in the first cooling circuit parallel to the ambient heat exchanger. Method for operating an internal combustion engine having a cooling system according to one of the preceding claims, characterized in that in a warm-up phase of the internal combustion engine only the pump (24) of the second cooling circuit is operated. A method according to claim 11, characterized in that in a first phase of the warm-up phase, the pump (24) is operated with a relatively low power and in a second phase of the warm-up phase with a relatively high power. Method for operating an internal combustion engine having a cooling system according to claim 5 or claim 5, characterized in that the delivery rate of the pump (18) of the first cooling circuit is regulated by the temperature of the coolant at the outlet of the second part-component radiator and a volume flow through the first part-component cooler is controlled by means of an adapted operation of the pump (24) of the second cooling circuit. Method for operating an internal combustion engine having a cooling system according to claim 10, characterized in that during or after filling of the cooling system with the coolant, the pump (18) of the first subcooling circuit is operated in conjunction with non-operation of an internal combustion engine (10) of the internal combustion engine. Connection element (28) with a at least two separate flow spaces (32, 34) forming the housing (30), wherein - A first flow space (32) having at least two inlet ports (36, 38), which are shut off by means of a device for preventing backflow, and an outlet port (40) is connected and - A second flow space (34) having at least two inlet ports (46, 48), of which at least one by means of a pressure-actuated valve (50) is shut off, and at least two outlet ports (52, 54) is connected.

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