EP3412883A1 - Combustion engine and motor vehicle - Google Patents

Abstract

It is an internal combustion engine with an internal combustion engine 12 having a cylinder head 14 and a cylinder housing 16, and provided with a cooling system comprising a coolant channel 18 of the cylinder head 14 and a coolant passage 20 of the cylinder housing 16, wherein the coolant passage 20 of the cylinder housing 16 at least is partially integrated into the cooling system parallel to the coolant channel 18 of the cylinder head 16, so that it is in principle possible to flow through only one or both of these coolant channels 18, 20 of coolant. A flow through the coolant channel 20 of the cylinder housing 16 is controllable in an internal combustion engine according to the invention by means of a Dehnstoff thermostatic valve 32. In this case, this expansion valve thermostat 32 is designed such that its temperature-dependent flow control requires a pilot flow of the coolant. Furthermore, it is provided that the expansion thermostatic valve 32 is associated with an influencing device 34, by means of which such a pilot flow of the coolant for the expansion valve thermostat 32 can be prevented or approved. This embodiment of the internal combustion engine allows regulation of the flow through the coolant channel 20 of the cylinder housing 16, on the one hand automatically works and on the other hand offers the possibility of complete suppression of such flow, whereby heating of the cylinder housing 16 as needed, especially after a cold start of the engine as quickly as possible can be done.

Description

The invention relates to an internal combustion engine with an internal combustion engine and a cooling system. The invention also relates to a motor vehicle with such an internal combustion engine.

Internal combustion engines for motor vehicles generally have a cooling system in which a coolant is pumped by means of one or more coolant pumps in at least one cooling circuit and thereby heat energy from integrated into the cooling circuit components, u.a. an internal combustion engine. This heat 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 intended for air conditioning of the interior of the vehicle ambient air discharged.

In the cooling systems of modern motor vehicles, the main control of the volumetric flow of the coolant can be effected by means of controllable coolant pumps, while the distribution of the volumetric flow to the individual components, each having a different cooling demand, can be controlled in particular by means of thermostatic 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 into the cooling circuit, in particular coolant ducts of a cylinder housing 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 in the cooling circuit integrated.

An internal combustion engine with a cooling system in which a distribution of the volume flows of the coolant to the individual components is not performed by means of thermostatic valves but by means of a distributor, is in the DE 10 2014 219 252 A1 described. This distributor device comprises a first locking slide, which can be moved by means of an electric motor, and a second, phase-wise moved by the first locking slide second locking slide wherein by means of the locking slide an operation-dependent adapted coolant supply to the various components of the cooling system is possible. The distribution device can also make it possible to allow a flow through a cylinder head of an internal combustion engine of the internal combustion engine, while a flow through a cylinder housing of the internal combustion engine is prevented. If a flow through the cylinder housing is completely prevented, the fastest possible warming up of the cylinder housing during a warm-up phase of the internal combustion engine can thereby be realized. The distribution device according to the DE 10 2014 219 252 A1 Although allows a substantially optimal adapted distribution of the flow rates of the coolant to the various components of the cooling system, but in particular due to the operation by means of the electric motor and the necessary for this active activation of the electric motor is relatively complex and therefore expensive.

The DE 10 2008 004 161 A1 discloses a method of operating an internal combustion engine including a coolant circuit carrying a first thermostat and carrying coolant, wherein the first thermostat opens at a first threshold temperature. The coolant circuit is also associated with a second thermostat, which opens at a second threshold temperature, the two threshold temperatures are different. In a full load operation, the engine receives the coolant at a first temperature over the first thermostat and in a part load operation at a second temperature via the second thermostat. The thermostats can be functionally based in particular on an expansion element ("wax particles"), which expands depending on the temperature and thereby releases a flow cross-section more or less.

Such thermostats or thermostatic valves are inexpensive to use because they are on the one hand structurally little expensive and on the other hand, due to the self-regulation of such thermostatic valves, make an active control unnecessary. On the other hand, such thermostatic valves require a so-called pilot flow of the coolant. This is a relatively small volume flow of the coolant, which must flow through such a thermostatic valve permanently, to ensure that the expansion element comes into contact with coolant whose temperature is approximately equal to that which has to be assigned to the previously flowed through component of the cooling system. If such a thermostatic valve would not permit such a pilot flow of the coolant, the coolant accumulating immediately in front of the thermostatic valve would heat up too slowly and thereby prevent a meaningful temperature-dependent volume flow control.

Although such a pilot flow is relatively small compared to the maximum flow rate that can flow through the thermostatic valve in the fully open state, this is not negligible. Consequently, this is noticeably slowed down by warming up a component of a cooling system, for example a cylinder housing, despite the fact that the thermostat valve assigned to this component is closed as far as possible.

The invention was based on the object in an internal combustion engine with a cylinder head and a cylinder housing comprehensive internal combustion engine and with a cooling system having cooling channels for both the cylinder head and the cylinder housing, in the simplest possible and thus cost-effective manner to achieve that, in particular a warm-up phase after a cold start of the internal combustion engine, the cylinder head is flowed through by coolant, while a flow through the cylinder housing is completely prevented.

This object is achieved by means of an internal combustion engine according to the patent claim 1. A motor vehicle with such an internal combustion engine is the subject of claim 13. Advantageous embodiments of the internal combustion engine according to the invention and thus the motor vehicle according to the invention are objects of the other claims and / or emerge from the following description of the invention.

According to the invention, an internal combustion engine is provided with an internal combustion engine having a cylinder head and a cylinder housing, and with a cooling system comprising a coolant passage of the cylinder head and a coolant passage of the cylinder housing, the coolant passage of the cylinder housing being at least partially parallel to the coolant passage of the cylinder head into the cylinder head Cooling system is integrated, so that it is basically possible to flow through only one or both of these coolant channels of coolant. A flow through the coolant channel of the cylinder housing (with simultaneous flow through the coolant channel of the cylinder head) is controllable in an internal combustion engine according to the invention by means of a (first) expansion valve thermostat and thus by means of a self-acting temperature-dependent thermostatic valve. In this case, this expansion valve thermostat is designed such that its temperature-dependent flow control requires a pilot flow of the coolant. It is provided that the expansion thermostatic valve is associated with an influencing device by means of which such a pilot flow of the coolant for the (first) expansion valve thermostat can be prevented or approved.

A motor vehicle according to the invention comprises at least one internal combustion engine according to the invention intended to generate a traction drive power. The motor vehicle may in particular be a wheel-based motor vehicle (preferably a car or a truck).

The invention is based on the idea of using a cost-effective, by means of a Dehnstoffelements automatically controlling thermostatic valve to regulate the flow through the coolant channel of the cylinder housing, which constructively and functionally requires a pilot flow of the coolant to perform a temperature-dependent flow control can. In order to prevent a flow through the coolant channel of the cylinder housing completely (and thus also the pilot flow through the Dehnstoff thermostatic valve) in spite of the use of such expansion valve thermostatic valve as needed, the influencing device according to the invention is assigned to the Dehnstoff thermostatic valve, which may also be relatively simple, so that a total of a relatively simple manner can realize a flow control of the coolant channel of the cylinder housing, on the one hand automatically works and on the other hand offers the possibility of complete suppression of such flow, thereby heating the cylinder housing if necessary, especially during a warm-up phase, especially after a cold start of the engine, can be done as quickly as possible.

According to a preferred embodiment of such an internal combustion engine according to the invention, it can be provided that the influencing device comprises a heating device for the (first) expansion valve thermostatic valve. The heating device, which can be controlled, in particular, by means of a control device (for example a motor control) of the internal combustion engine, permits a temperature control of the expansion element of the expansion element thermostatic valve, which is independent of a temperature control by means of the coolant. This makes it possible to design the thermostatic valve such that this completely prevents flow through the coolant channel of the cylinder housing in the most closed state, whereas when an automatic control of the volume flow of the coolant through the cooling channel of the cylinder housing in dependence on the temperature of the coolant should be provided in that the expansion element of the thermostatic valve is heated to such an extent by means of the heating device that this permits at least one pilot flow of the coolant which can then ensure the automatic control of the expansion thermostat valve. In this case, the use of the heating device is not a switch between complete suppression of the flow through the coolant channel of the cylinder housing and an automatic control as a function of the temperature of the coolant by allowing a pilot flow limited, but the heater can in principle be used at any time during operation of the internal combustion engine, if necessary, to superimpose an optionally slow automatic control by means of the expansion element of the expansion valve thermostat , This may be the case, for example, after a load jump, ie after a spontaneous, relatively large load increase for the operation of the internal combustion engine, if the automatic control by means of the expansion element tends to react too slowly. As a result, the best possible adaptation of the volume flow of the coolant through the coolant channel of the cylinder housing and thus the cooling effect for the cylinder housing can be achieved.

According to a further preferred embodiment of an internal combustion engine according to the invention can also be provided that the influencing device comprises a (first) control valve. By means of this (first) control valve, if necessary, a flow through the coolant channel of the cylinder housing can be prevented, thus thus also a pilot flow through the expansion valve thermostatic, which can be designed such that this in the widest possible closed position passes a pilot flow is prevented. In this case, the control valve may be designed such that it either a flow through the coolant channel of the cylinder housing prevents or largely releases, so that would be done after such a release a volume flow control exclusively by means of the expansion thermostatic valve. As a result, a constructively simplest possible design for the influencing device and thus also for the internal combustion engine can be realized. On the other hand, however, it is also possible to design the control valve in such a way that a flow through the coolant channel of the cylinder housing can be influenced in one or more intermediate positions or steplessly between the fully closed and the completely open position by means of the control valve in dependence on the position of the control valve. This in turn allows, within limits, a superposition of the volume flow control achievable by means of the expansion thermostatic valve.

Furthermore, it can be provided for an internal combustion engine according to the invention, that the influencing device comprises a second expansion valve thermostatic, whose starting control temperature is preferably below the starting control temperature of the first expansion valve thermostat. In this case, a limit value or a limit value range for the temperature of the respective expansion thermostatic valve is used as "start regulation temperature" or understood for the temperature of the respective expansion material thermostatic valve flowing coolant, from which a temperature-dependent valve opening takes place with the aim of a flow control. Consequently, it can be provided according to the invention that the first expansion thermostatic valve is structurally designed so that it always lets through or let through a pilot flow while the second expansion thermostatic valve is designed and integrated into the cooling system, in particular in the coolant channel of the cylinder housing. in the completely closed state, this completely prevents flow through the coolant channel of the cylinder housing (at least in the section comprising the first expansion valve), as a result of which the pilot valve flow which is fundamentally possible in principle is also prevented by the first expansion valve for thermosetting material. On the other hand, if the second expansion thermostatic valve opens, the pilot flow for the first expansion thermostatic valve is thereby released, so that from then on, the regulation of the volume flow of the coolant through the coolant channel of the cylinder housing can be controlled automatically by means of the first expansion thermostatic valve. Due to the lower starting control temperature of the second expansion thermostatic valve in comparison to that of the first expansion thermostatic valve can be ensured in a relatively simple manner that depending on the temperature of the coolant channel of the cylinder housing flowing through the coolant, the second expansion thermostatic valve always further than the first expansion material Thermostatic valve is opened (as long as both are not fully open), so that a flow control for the coolant channel of the cylinder housing by flowing coolant can be realized only by means of the first Dehnstoff thermostatic valve, as soon as a pilot flow has been released by means of the second expansion valve thermostat.

According to a preferred development of such an internal combustion engine according to the invention, provision can be made for the second expansion thermostatic valve to be acted upon by means of a coolant flow via a connecting line which leaves the coolant line of the cylinder head or downstream thereof (with respect to a flow direction provided for the cooling system). The second expansion thermostatic valve can thus inhibit or release a pilot flow for the first expansion valve thermostat depending on the temperature of the cylinder head or the coolant flowing through the cylinder head or has flowed through shortly before.

According to a preferred embodiment of an internal combustion engine according to the invention, it may be provided that the cooling system comprises one of the coolant channels of the cylinder head and the cylinder housing, a (first) coolant pump and a main radiator Main cooling circuit as well as a outgoing from the main cooling circuit and opening into the main cooling circuit and thus has a section of the main cooling circuit bypassing sidewalk to form a secondary cooling circuit. A heating heat exchanger and / or an EGR cooler, in particular a LP EGR cooler, and / or an ATL cooler and / or a second coolant pump may preferably be integrated into the branch line. A "heat exchanger" is understood to mean a heat exchanger in which a heat transfer from the coolant of the cooling system to ambient air, which is provided for heating an interior of a motor vehicle according to the invention, takes place. The term "EGR cooler" is understood to mean a heat exchanger which is integrated into an exhaust gas recirculation line (in a configuration as an LP EGR cooler: into a low-pressure exhaust gas recirculation line) and serves to cool exhaust gas recirculated via the exhaust gas recirculation line. As "ATL cooler" is meant a heat exchanger which is integrated in an exhaust gas turbocharger of the internal combustion engine and can be used for cooling the exhaust gas turbocharger, in particular a bearing block of the exhaust gas turbocharger.

By integrating these components of the cooling system in the branch line on the one hand allows to realize a further adapted flow control for this. This can be done, in particular, by means of the second coolant pump, which is integrated into the branch line and can be operated, in particular, by an electric motor and can be activated by means of a control device of the internal combustion engine. Thus, by means of the second coolant pump, a volumetric flow of the coolant caused by the first coolant pump for the main cooling circuit can be influenced with effect for the branch line. On the other hand, it can be prevented by this integration that these components, which may have a relatively large flow resistance, adversely affect the flow through the main cooling circuit.

The first coolant pump may advantageously be configured as a coolant pump (so-called mechanically driven coolant pump) driven directly or indirectly, ie via a transmission, by means of an output shaft of the internal combustion engine, resulting in a relatively simple structural design for the same. In this case, the coolant pump can also be configured as being independent of the drive speed with regard to the delivery rate. Alternatively, there is also the possibility that the first coolant pump is driven by an electric motor and for this purpose can be controlled in particular by means of a control device to achieve an adjustment of the delivery rate.

In particular, in one embodiment of the first coolant pump as a mechanically driven coolant pump, a flow of coolant in the cooling system can be realized by means of a second coolant pump integrated into the branch line and driven by an electric motor even if the internal combustion engine and therefore also the first coolant pump is not operated. This may be relevant, for example, to ensure a heating functionality for the interior heating of the motor vehicle even with active start-stop system and / or after the manual termination of the operation of the internal combustion engine. Optionally, such additional heating may also be relevant for other components of the cooling system. In addition, despite an internal combustion engine not operated for individual components of the cooling system, post-cooling may be advantageous in order to avoid local temperature congestion and thus overheating, by further dissipating or at least distributing heat energy via the cooling system.

According to a preferred embodiment of such an internal combustion engine according to the invention can also be provided that the main cooling circuit comprises a bypass for the main radiator, wherein a distribution of coolant flow on the one hand to the main radiator and on the other hand on the main radiator bypass bypass means of a distributor controllable and preferably controllable. The distributor can be designed in a structurally advantageous manner in the form of another expansion thermostatic valve. By means of the bypass for the main radiator is made possible to operate the cooling system and concretely the main cooling circuit on the one hand in a small, the main radiator circuit, whereby the fastest possible warm-up from the other components integrated into the cooling system during a warm-up phase of the internal combustion engine can be supported a heat transfer from the coolant to ambient air in the flow through the main radiator is prevented. If, on the other hand, at least one of the components to be cooled, in particular the cylinder head of the internal combustion engine, reaches its operating temperature range, the cooling system or the main cooling circuit can, on the other hand, be operated in a large cycle integrating the main cooler, whereby then in the sense of normal operation of the Cooling system heat energy can be transferred in the main radiator from the coolant to the ambient air to prevent overheating of the coolant and the components to be cooled by this.

The section of the main cooling circuit bypassed by the branch line can preferably comprise the main cooler and, if provided, furthermore preferably also the bypass to the main cooler. This can ensure that a flow through the By-pass is unaffected by whether the main cooling circuit is operated in a small or large circuit.

According to a preferred embodiment of an internal combustion engine according to the invention, in which a bypass section bypassing a section of the main cooling circuit is provided, provision may be made for a shut-off valve to be integrated in the section of the main cooling circuit bypassing the branch section. By means of the shut-off valve, coolant can be prevented from flowing back into the section of the main cooling circuit to be bypassed from the branch line. This can in particular ensure that the coolant flowing through the secondary cooling circuit flows through at least the coolant channel of the cylinder head, which is particularly important for the function of a heating heat exchanger integrated in the auxiliary section, in order to ensure good functionality and in particular a relatively fast response of an interior heating for the internal combustion engine to ensure comprehensive motor vehicle after a cold start of the internal combustion engine. Even the fastest possible warming up of the other components integrated into the branch line can be advantageous. For example, this can prevent or at least reduce condensation of liquid from exhaust gas recirculated via an exhaust gas recirculation line.

The shut-off valve may preferably be in the form of a differential pressure valve, in particular in the form of a check valve, whereby an active control of such a shut-off valve can be dispensed with. But as possible is also an actively controllable design of the shut-off valve.

According to a preferred embodiment of an internal combustion engine according to the invention it can be provided that the (first) expansion valve and preferably also the associated influencing device by means of a bypass is / are bypassable, wherein a volume flow of the coolant via the bypass by means of a (second) control valve is controllable. This bypass in combination with the associated control valve can serve in particular to temporarily override a temperature-dependent volumetric flow control by means of the (first) expansion thermostatic valve in order, for example, to ensure a sufficient cooling effect for the cylinder housing after a load step, so that damage to the cylinder housing and / or or the coolant can be avoided by boiling.

The indefinite articles ("an", "an", "an" and "an"), in particular in the claims and in the general explanatory description of the claims, are to be understood as such and not as numerals. Corresponding to this concretized components are thus to be understood that they are present at least once and may be present more than once.

Fig. 1:

schematisch eine erste Ausgestaltungsform einer erfindungsgemäßen Brennkraftmaschine;

Fig. 2:

schematisch eine zweite Ausgestaltungsform einer erfindungsgemäßen Brennkraftmaschine; und

Fig. 3:

schematisch eine dritte Ausgestaltungsform einer erfindungsgemäßen Brennkraftmaschine.

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

Fig. 1:

schematically a first embodiment of an internal combustion engine according to the invention;

Fig. 2:

schematically a second embodiment of an internal combustion engine according to the invention; and

3:

schematically a third embodiment of an internal combustion engine according to the invention.

The Fig. 1 schematically shows a first embodiment of an internal combustion engine according to the invention, which serves to generate a traction drive power for a motor vehicle 10 according to the invention. The internal combustion engine comprises an internal combustion engine 12, which may be designed, for example, as a reciprocating piston engine operating according to the Otto or Diesel principle and which comprises a cylinder head 14 and a cylinder housing 16. Both in the cylinder housing 16 and in the cylinder head 14, a coolant channel 18, 20 is integrated, which are integrated in a parallel arrangement in a cooling system of the internal combustion engine and thereby independently of each other in different coolant, but always the coolant channels 18, 20 of the Cylinder head 14 and the cylinder housing 16 comprehensive cooling circuits is funded, can be flowed through. The coolant channels 18, 20 of the cylinder head 14 and of the cylinder housing 16 are both connected to the outlet of a first coolant pump 22 via a coolant line, which is likewise integrated in the cylinder housing 16 of the internal combustion engine 12. From this coolant line may optionally proceed to another coolant line, is passed through the coolant in an additional circuit through a motor oil cooler 66 and a transmission oil cooler 68. This coolant line opens upstream of the first coolant pump 22 in a local coolant line of the cooling system.

For example, the first coolant pump 22 may be directly or indirectly, i. E., Driven by an output shaft (in particular crankshaft) of the internal combustion engine 12, i. be driven by a transmission, which may also be configured adjustable in terms of delivery so that the flow rate is independent of the drive speed variable. To adjust the delivery rate, this can be controlled correspondingly by means of a control device 24, in particular a motor control of the internal combustion engine.

Further coolant lines of the cooling system in combination with the coolant channels 18, 20 of the cylinder head 14 and the cylinder housing 16 form a main cooling circuit and a secondary cooling circuit. The auxiliary cooling circuit comprises a branch line 26, which leaves the main cooling circuit and opens again into the main cooling circuit, thereby bypassing a section of the main cooling circuit in which a main cooler 28 and a bypass 30 for the main cooler 28 are integrated. The coolant channels 18, 20 of the cylinder head 14 and the cylinder housing 16, however, are integrated into a portion of the main cooling circuit, which also represents a portion of the auxiliary cooling circuit. Coolant, which flows through the branch line 26, consequently also flows through the coolant channel 18 of the cylinder head 14 and, if this is not prevented by means of a first expansion thermostatic valve 32 and an associated influencing device 34, the coolant channel 20 of the cylinder housing 16. A flow through the coolant channel 18th the cylinder head 14 and optionally also the coolant channel 20 of the cylinder housing 16 by means of the guided over the branch line 26 coolant is thereby ensured by an integrated into the bypass 30 to the main cooler 28 shut-off valve 36 in the form of a check valve 36. This effect of the check valve 36 may be particularly relevant if the coolant flowing in the auxiliary cooling circuit is conveyed exclusively by means of a second coolant pump 38 integrated in the auxiliary section 26. The first coolant pump 22 would not be operated or due to a corresponding setting, the delivery rate of the first coolant pump 22 would be substantially zero or at least negligible compared to the delivery rate of the second coolant pump 38.

In the branch line 26, a heating heat exchanger 40 and optionally an EGR cooler 42 and an ATL cooler 44 are further integrated. The second coolant pump can be driven by means of an electric motor, which can be controlled by means of the control device 24.

In a coolant line of the main cooling circuit, which adjoins the outlet side of the coolant channel 20 of the cylinder housing 16, the first expansion thermostatic valve 32 and the associated influencing device 34, which in the embodiment according to the Fig. 1 in the form of a second expansion thermostatic valve 46 arranged downstream of the first expansion thermostatic valve 32 is integrated. This coolant line passes downstream of the two expansion thermostatic valves 32, 46 in a coming from the outlet of the coolant channel 18 of the cylinder head 14 coolant line of the main cooling circuit, which leads to a distributor 48. By means of the distributor device 48, a distribution of coolant flowing through the main cooling circuit to either the main cooler 28 or the bypass 30 to the main cooler 28 is regulated as a function of the temperature. The distributor 48 is designed in the form of a further expansion thermostatic valve 50.

The first expansion thermostatic valve 32 is designed such that it passes in the widest possible closed position a relatively small pilot flow of the coolant zubeziehungsweise, so that by means of the first expansion thermostatic valve 32 an automatic, temperature-dependent control of the guided through the coolant passage 20 of the cylinder housing 16 Volumetric flow of the coolant is realized as soon as such a pilot flow is actually present. However, this pilot flow is prevented when the second expansion thermostatic valve 46 is in its fully closed position. The second expansion thermostatic valve 46 opens only when the coolant, which has previously passed through the coolant channel 18 of the cylinder head 14, has reached a defined limit temperature (for example 87 ° C.) which approximately corresponds to the starting control temperature of the second expansion valve thermostat 46. In order to allow the second expansion valve thermostat 46, depending on the temperature of the coolant, which has previously flowed through the coolant channel 18 of the cylinder head 14, a connecting line 52 is provided, which from the outlet of the coolant channel 18 of the cylinder head 14th coming refrigerant line goes off and leading to the second expansion thermostatic valve 46. Via this connecting line 52, a pilot flow can be performed by the second expansion valve thermostatic valve 46, which causes an opening of the second expansion valve thermostat 46 upon reaching the associated starting control temperature. As soon as the second expansion thermostatic valve 46 is opened, a pilot flow flows through the first expansion thermostatic valve 32, so that then the first expansion thermostat valve 32 is continuously acted upon in a relatively small extent with coolant coming from the coolant channel 20 of the cylinder housing 16. From reaching an associated starting control temperature, which may for example be 105 ° C, the first expansion thermostat valve 32 then opens depending on the temperature more or less to realize a flow control for the coolant passage 20 of the cylinder housing 16 by flowing coolant.

An internal combustion engine according to the invention according to, for example, the Fig. 1 allows an advantageous, temperature-dependent distribution of coolant to the various components of the cooling system, wherein for the coolant distribution structurally relatively simple configured components, in particular automatically controlling Dehnstoff thermostatic valves 32, 46, 50 are used. At the same time, it is possible to temporarily completely prevent a flow through the coolant channel 20 of the cylinder housing 16, which has a positive effect on the speed at which the cylinder housing 16 warms up during a warm-up phase after a cold start of the internal combustion engine. Such achievable relatively rapid warming of the cylinder housing 16 has a positive effect on the fuel consumption of the internal combustion engine 12, because friction losses, resulting from the cyclical movements of pistons in cylinders (not shown) formed in the cylinder housing 16, only with the Achieving a defined operating temperature range of the internal combustion engine 12 and in particular a defined operating temperature range of lubricants used for lubricating these relative movements is minimized.

Concretely, for operation of the internal combustion engine according to the Fig. 1 be provided that immediately after a cold start of the internal combustion engine, only the second, driven by an electric motor 54 coolant pump 38 is operated, whereby coolant is conveyed substantially exclusively in the subcooling, the components integrated into the branch line 26 and further the first coolant pump 22 and includes the coolant channel 18 of the cylinder head 14. A flow through the coolant channel 20 of the cylinder housing 16 is thereby prevented due to the still closed first and second expansion thermostatic valves 32, 46 and the first coolant pump 22 is not operated or for this is the lowest possible and in particular as zero delivery rate set. By conveying coolant essentially exclusively in the auxiliary cooling circuit, it can be achieved, in particular, that heat energy which the coolant has absorbed when the cylinder head 14 first and relatively quickly warms up during operation of the internal combustion engine 12 is transferred as completely as possible, in particular to the heating heat exchanger 40 can to achieve the fastest possible effectiveness of the heater core 40 integrating heater for an interior of the motor vehicle 10 to achieve. Furthermore, advantageously, the EGR cooler 42 can be conditioned in order to avoid condensate formation in exhaust gas, which flows via an EGR cooler 42 integrating exhaust gas recirculation line (not shown).

In a second operating phase after such a cold start of the internal combustion engine, the first coolant pump 22 can be put into operation or its delivery capacity can be increased in order to realize an overall higher volume flow of the coolant in the cooling system. As a result, in particular even an overheating of the cylinder head 14 can be avoided and an increasing heating of further components integrated in the cooling system can be sought. In this case, coolant is already promoted to a relevant extent within the main cooling circuit, wherein by means of the further expansion thermostatic valve 50, the promoted in the main cooling circuit coolant is passed essentially exclusively in the bypass 30 to the main radiator 28, as long as the other expansion thermostatic valve 50 reaching coolant has a temperature which is below a starting control temperature (eg 95 ° C) for this further expansion valve thermostat 50. This is intended to prevent heat energy, which has been transferred to the coolant, in particular in the flow through the coolant channel 18 of the cylinder head 14, already being transferred to the ambient air in the main cooler 28. Rather, this heat energy should continue to be used as completely as possible for the fastest possible heating of components integrated in the cooling system.

As soon as the coolant arriving at the further expansion thermostatic valve 50 has a temperature above the associated starting control temperature, this further expansion thermostatic valve 50 opens depending on the temperature, whereby an increasing proportion of the incoming coolant is conducted via the main cooler 28. This is to prevent overheating of the coolant and the components integrated in the cooling system.

Already before, the second expansion thermostatic valve 46 has already opened due to a lower starting control temperature (in comparison to the other expansion thermostatic valve 50), so that a pilot flow through the first expansion thermostat valve 32 is present. The first expansion thermostatic valve 32 then opens, as soon as this pilot flow of the refrigerant passage 20 of the cylinder housing 16 flowing coolant the associated starting control temperature (eg 105 ° C), which is higher than those of the other two expansion thermostatic valves 46, 50 has reached a then also necessary for the cylinder housing 16 to ensure cooling.

In the internal combustion engine according to the Fig. 1 a bypass 56 is still provided for both the first expansion thermostatic valve 32 and the second expansion thermostatic valve 46. In this bypass 56, a control valve 58 is integrated by the control device 24th is controlled and in the closed position prevents flow through the bypass 56 by means of the coolant and allows in the closed position. The bypass 56, the upstream of the first Dehnstoff thermostatic valve 32 from the coming of the coolant passage 20 of the cylinder housing 16 coolant line, for example, according to the Fig. 1 downstream of the second expansion thermostatic valve 46 open into the local coolant line. Alternatively, it can also be provided that this bypass 56 opens into a section of the main cooling circuit, which is located downstream of the bypassed from the secondary section 26 section of the main cooling circuit and in particular immediately upstream of the first coolant pump 22. These alternatively or optionally also cumulatively provided mouth sections of the bypass 56 are in the Fig. 1 shown with dashed lines.

The bypass 56 for the first expansion thermostatic valve 32 and the associated influencing device 34 (second expansion thermostatic valve 46) serves to temporarily allow a flow through the coolant channel 20 of the cylinder housing 16 with a larger volume flow, than by the temperature-dependent control by means of the first Dehnstoff thermostatic valve 32 would be present. This may in particular be the case when, with still relatively cold coolant, the internal combustion engine 12 is operated with a relatively high and in particular full load, which could lead to a relatively strong local heating of the cylinder housing 16, which is to be compensated by an increased cooling , A volumetric flow control exclusively by means of the first expansion thermostatic valve 32 could react too slowly in this case and therefore be insufficient.

The cooling system in the Fig. 2 shown internal combustion engine differs from that according to the Fig. 1 essentially in that the influencing device 34, which is associated with the first expansion valve thermostat 32, a control valve 60 instead of a second expansion valve thermostat 46 includes, which is controllable by means of the control device 24 (engine control). This control valve 60 prevents in the closed position, a flow through the coolant and thus also a pilot flow through the first expansion valve thermostat 32, while in the open position such flow is not substantially hindered. If this control valve 60 is in the open position, at least one pilot flow and each volume flow set by the first expansion valve thermostat 32 can thus flow through the coolant channel 20 of the cylinder housing 16.

Another difference between the cooling systems according to the Fig. 1 and 2 lies in the arrangement of the distributor 48 (further expansion valve thermostatic valve 50), by means of which a division of the main cooling circuit flowing through the coolant to the main cooler 28 and the associated bypass 30 takes place. While in the cooling system according to the Fig. 1 the further expansion thermostatic valve 50 is located in the branch between the bypass 30 and the main cooler 28 and thus upstream of the main cooler 28 is in the cooling system according to the Fig. 2 an arrangement in the junction of the bypass 28 and the main radiator 30 and thus provided downstream of the main radiator 28. These different arrangements for the other expansion thermostatic valve 50 can make sense different starting control temperatures. While these for the further expansion valve thermostat 50 according to the Fig. 1 For example, may be 95 ° C, for the other expansion thermostatic valve 50 of the cooling system according to the Fig. 2 For example, be provided a starting control temperature of 90 ° C. Basically, there is the possibility, even with the cooling system according to the Fig. 2 an arrangement of the other expansion thermostatic valve 50 according to the Fig. 1 and vice versa.

Furthermore, in the cooling system of the internal combustion engine according to the Fig. 2 no bypass for the local first expansion thermostatic valve 32 and the associated Beaufschlagungselement 34 (control valve 60) is provided. In principle, however, can also in the cooling system according to the Fig. 2 Such a bypass 56, as this for the cooling system according to the Fig. 1 is intended to be integrated.

The cooling system of the internal combustion engine according to the Fig. 3 differs from those according to the Fig. 1 and 2 essentially in the embodiment of the first expansion material thermostatic valve 32 associated influencing device 34, which is formed in this case in the form of a heater 62 for the first Dehnstoff thermostatic valve 32. In this case, it is also provided that the first expansion thermostatic valve 32 is designed such that this fully prevents flow in the widest possible or fully closed position by means of the coolant, so that then no pilot flow is possible. A pilot flow through the first expansion valve thermostat 32 and thus also through the coolant passage 20 of the cylinder housing 16 is only present when the temperature of a Dehnstoffelements of the first Dehnstoff thermostatic valve 32 is so high that this opens a piece. A heating of the expansion element up to the opening temperature is, if then an automatic flow control by means of the first expansion valve thermostat 32 is provided, effected by means of the heater 62.

In the cooling system of the internal combustion engine according to the Fig. 3 is again an arrangement of the distribution device 48 (further expansion valve thermostat 50) corresponding to that of the cooling system according to the Fig. 1 intended. Alternatively, however, an arrangement according to the Fig. 2 be provided.

Furthermore, in the cooling system of the internal combustion engine according to the Fig. 3 no bypass for the local first expansion thermostatic valve 32 and the associated influencing device 34 is provided. Basically, such a bypass 56 according to the Fig. 1 but also in the cooling system according to the Fig. 3 be provided.

LIST OF REFERENCE NUMBERS

10

motor vehicle

12

internal combustion engine

14

cylinder head

16

cylinder housing

18

Coolant channel of the cylinder head

20

Coolant channel of the cylinder housing

22

first coolant pump

24

control device

26

Nebenstrecke

28

main cooler

30

Bypass for the main radiator

32

first expansion thermostatic valve

34

influencing device

36

Shut-off valve Check valve

38

second coolant pump

40

Heater core

42

EGR cooler

44

ATL cooler

46

second expansion thermostatic valve

48

distributor

50

further expansion valve thermostatic valve

52

connecting line

54

electric motor

56

Bypass for the first expansion thermostatic valve

58

Control valve of the bypass for the first expansion thermostatic valve

60

Control valve of the influencing device

62

heater

64

Inlet of the heating heat exchanger

66

Engine oil cooler

68

Transmission oil cooler

Claims (13)

An internal combustion engine having an internal combustion engine (12) having a cylinder head (14) and a cylinder housing (16) and a cooling system comprising a coolant passage (18) of the cylinder head (14) and a coolant passage (20) of the cylinder housing (16) in which the coolant channel (20) of the cylinder housing (16) is integrated at least partially parallel to the coolant channel (18) of the cylinder head (14) into the cooling system and wherein a flow through the coolant channel (20) of the cylinder housing (16) by means of a (first) Dehnstoff thermostatic valve (32) is controllable, the temperature-dependent volume flow control requires a pilot flow of the coolant, characterized in that the (first) expansion valve thermostat (32) is associated with an influencing device (34), by means of such a pilot flow of the coolant for ( first) expansion valve thermostat (32) can be prevented or approved. Internal combustion engine according to claim 1, characterized in that the influencing device (34) comprises a heating device (62) for the (first) expansion valve thermostat (32). Internal combustion engine according to one of the preceding claims, characterized in that the influencing device (34) comprises a control valve (60). Internal combustion engine according to one of the preceding claims, characterized in that the influencing device (34) comprises a second expansion-valve thermostat (46). Internal combustion engine according to claim 4, characterized in that the starting control temperature of the second expansion thermostatic valve (46) is below the starting control temperature of the first expansion thermostatic valve (32). Internal combustion engine according to claim 4 or 5, characterized in that the second expansion thermostatic valve (46) via a connecting line (52), the (8) of the coolant line (18) of the cylinder head (14) or downstream thereof, acted upon by means of a coolant flow. Internal combustion engine according to one of the preceding claims, characterized in that the cooling system comprises a main cooling circuit comprising the coolant channels (18, 20) of the cylinder head (14) and the cylinder housing (16), a (first) coolant pump (22) and a main radiator (28) Having an outgoing from the main cooling circuit and opening into the main cooling circuit and thus a portion of the main cooling circuit bypassing secondary line (26) for forming a secondary cooling circuit. Internal combustion engine according to claim 7, characterized in that in the branch line (26) a heating heat exchanger (40) and / or an EGR cooler (42) and / or an ATL cooler (44) and / or a second coolant pump (38) integrated is. Internal combustion engine according to claim 7 or 8, characterized in that the main cooling circuit comprises a bypass (30) for the main radiator (28), wherein a distribution of coolant flow on one side the main radiator (28) and on the other hand on the main radiator (28) bypassing Bypass (30) by means of a distributor (48) is controllable. Internal combustion engine according to claim 9, characterized in that the distributor device (48) comprises a further expansion valve (50). Internal combustion engine according to any one of claims 7 to 10, characterized in that in the bypass of the branch line (26) portion of the main cooling circuit, a shut-off valve (36) is integrated. Internal combustion engine according to one of the preceding claims, characterized in that the (first) expansion material thermostatic valve (32) by means of a bypass (56) is bypassed, wherein a volume flow of the coolant through this bypass (56) by means of a control valve (58) is controllable. Motor vehicle (10) having an internal combustion engine provided for generating a traction drive power according to one of the preceding claims.

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