EP1509687A1

EP1509687A1 - Method for regulating the heat of an internal combustion engine for vehicles

Info

Publication number: EP1509687A1
Application number: EP03714903A
Authority: EP
Inventors: Marco Braun; Christoph Burckhardt; Michael Haas; Roland LÜTZE; Alexander Müller; Michael Reusch; Ulrich Springer; Jens Von Gregory
Original assignee: DaimlerChrysler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2002-05-31
Filing date: 2003-03-29
Publication date: 2005-03-02
Anticipated expiration: 2023-03-29
Also published as: JP4164690B2; WO2003102394A1; EP1509687B1; US7128026B2; DE10224063A1; US20060005790A1; DE50313040D1; JP2005529269A

Abstract

The invention relates to a method for regulating the heat of an internal combustion engine for vehicles, with a coolant circuit and controllable devices for influencing the thermal economy of the internal combustion engine. According to the invention, a coolant temperature and additional operating parameters of the internal combustion engine are recorded, and the controllable devices are controlled according to the coolant temperature and the additional operating parameters of the internal combustion engine. The invention provides that a regulation of the coolant temperature and/or of the additional operating parameters ensues in such a manner that, by using a main characteristics map, an initial value for determining a manipulated variable is prescribed according to the rotational speed and the load of the internal combustion engine, and this initial value is corrected by a controller according to the coolant temperature and/or the additional operating parameters. This method is used, e.g. for the management of heat in efficiency-optimized direct injection diesel engines.

Description

Process for regulating the heat of an internal combustion engine for

vehicles

The invention relates to a method for heat regulation of an internal combustion engine for vehicles with a coolant circuit and controllable devices for influencing the heat balance of the internal combustion engine, wherein a coolant temperature and other operating parameters of the internal combustion engine are recorded and the controllable devices as a function of the coolant temperature and the further operating parameters of the internal combustion engine can be controlled.

From the German published patent application DE 197 28 351 AI a method for heat regulation of an internal combustion engine for vehicles is known, in which a web temperature between the exhaust valves and performance characteristics of the internal combustion engine are taken into account for a coolant temperature. In addition to the temperature values themselves, their change per unit of time is also recorded. As a performance parameter, it is proposed to take into account the amount of fuel introduced into a combustion chamber per unit of time or working cycle. By means of the method proposed there, the amount of heat dissipated through the coolant circuit is regulated via an electrically controllable fan, electrically controllable water pumps, an electrically controllable thermostat and an electrically controllable radiator blind. In the start-up phase of an internal combustion engine, the water pumps are first put into operation and regulated with increasing temperature or increasing heat, then the thermostats, the radiator blind and finally the fan in Put into operation and regulated. If the temperatures of the internal combustion engine cannot be controlled by means of the coolant circuit, provision is made to reduce the performance of the internal combustion engine for safety.

The invention is intended to provide a method for regulating the heat of an internal combustion engine for vehicles, which can be used with minor changes for different internal combustion engines with different components.

According to the invention, a method for regulating the heat of an internal combustion engine for vehicles with a coolant circuit and controllable devices for influencing the heat balance of the internal combustion engine is provided, wherein a coolant temperature and further operating parameters of the internal combustion engine are recorded and the controllable devices are controlled as a function of the coolant temperature and the further operating parameters of the internal combustion engine in which the coolant temperature and / or the further operating parameters are regulated in such a way that at least two output values for determining a manipulated variable for the controllable devices are determined on the basis of at least two different reference variables, the at least two output values are compared and the larger output value in the manipulated variable is implemented and transferred to the controllable devices.

In this way, a maximum linkage of the determined output values is provided, in that only the larger output value is converted into the manipulated variable. Such a Max link creates an interface for expanding the control structure. Additional functionalities or requirements can be fed into the Max link without requiring any further changes to the rest of the regulatory structure. For example, requirements from climate control or engine issues due to cooling of the exhaust gas recirculation or charge air cooling are taken into account by determining an output value based on these requirements, comparing it with the other output values and then taking it into account if it is greater than the other determined output values.

The problem underlying the invention is also solved by a method for heat regulation of an internal combustion engine for vehicles with a coolant circuit and controllable devices for influencing the heat balance of the internal combustion engine, wherein a coolant temperature and other operating parameters of the internal combustion engine are recorded and the controllable devices as a function of the coolant temperature and further operating parameters of the internal combustion engine can be controlled, in which the coolant temperature and / or the further operating parameters are regulated in such a way that an output value for determining a manipulated variable is specified by means of a basic map as a function of the speed and load of the internal combustion engine, and this output value is determined by means of a Controller depending on the coolant temperature and / or the other operating parameters is corrected.

Since the regulation is carried out via the correction of a basic map, the control structure is suitable for different applications, since only the basic map or the correction controller need be changed to adapt to different internal combustion engines. This means that different motors with different components can be operated with the same control structure.

In a development of the invention, a hysteresis characteristic curve is used when determining a manipulated variable.

Such a hysteresis characteristic curve can be applied both to the controllers and to the basic characteristic diagram, especially in transition areas, for example when switching on the coolant pump to prevent uncontrolled switching.

In a further development of the invention, setpoints of a coolant temperature and a component temperature of the internal combustion engine are determined by means of characteristic maps as a function of a speed and an injection quantity of the internal combustion engine.

In this way, the setpoints for coolant and component temperature can be specified depending on the operating point.

In a further development of the invention, several states of the system comprising the internal combustion engine and the coolant circuit are defined, each of which is assigned to different values of the coolant temperature and / or of the further operating parameters and in which the controllable devices for controlling at least the coolant temperature are at least partially controlled differently.

A clear regulatory structure can be achieved through these measures. In addition, different control characteristics can be provided in the different states or controllable devices can be set to maximum or zero throughput without any control.

In a further development of the invention, a change in the various states is triggered by exceeding or falling below predefined limit values, an ambient temperature, a component temperature of the internal combustion engine, a coolant temperature, a charge air temperature and / or a pressure of an air conditioning compressor, and in the individual states a coolant temperature and are regulated in order to regulate a component temperature of the internal combustion engine settings of a coolant pump, a heating pump, a mixing valve between a cooler and a bypass circuit, a radiator blind, a cooler fan, an air conditioning compressor and / or an injection system of the internal combustion engine.

Through these measures, the current state of the heat balance of an internal combustion engine is known exactly, and it is possible to react quickly to changes in the heat balance. As a result, only a small safety distance from critical areas of the internal combustion engine has to be maintained, as a result of which optimal heat management can be achieved. In this way, with a low consumption, wear and low emissions, a good heating or Climate comfort can be achieved.

Further features and advantages of the invention emerge from the claims and the following description of a preferred embodiment of the invention in conjunction with the drawings. The drawings show:

1 shows a schematic representation of an internal combustion engine for a vehicle for carrying out the method according to the invention,

2 shows the input and output variables of the method according to the invention,

Fig. 3 shows a more detailed representation of the formation of

Control variables in the method and

Fig. 4 shows the various possible states that the system of internal combustion engine and coolant circuit can assume.

1, an internal combustion engine 10 is shown, which is provided with a coolant circuit and is arranged in a motor vehicle. By means of the system of internal combustion engine 10 and coolant circuit, as shown schematically in FIG. 1, and the others In the devices shown, the method according to the invention can be carried out. A coolant circulates in the coolant circuit shown, a direction of flow of the coolant in the coolant circuit being indicated at different points by an arrow. Starting from an outlet opening 12 of the internal combustion engine 10, coolant reaches a controllable mixing valve 14 which is designed as a rotary slide valve. The mixing valve 14 is adjusted by means of an electric motor 16, which in turn is controlled by a central control device 18. A control by means of pulse-width modulated signals (PWM) is indicated in the illustration in FIG. 1. By means of the mixing valve 14, the coolant flow coming from the internal combustion engine 10 is conducted via a bypass line 20 or via a vehicle radiator 22.

Downstream of the vehicle radiator 22, the bypass line 18 opens again into a main line 24, which leads to a coolant pump 26. The coolant pump 26 is driven mechanically by the internal combustion engine 10 and is provided with a magnetic coupling 28 which can be controlled by the control unit 18. By means of the magnetic coupling 28, the coolant pump 26 can also be switched on or off while the internal combustion engine 10 is running. Instead of a mechanically driven coolant pump, an electrically driven coolant pump could also be used. Starting from the coolant pump 26, the coolant returns to the internal combustion engine 10.

Upstream of the mixing valve 14, a heating circuit line 30 branches off from the line connecting the coolant outlet 12 and the mixing valve 14. The heating circuit line 30 first leads to a heating pump 32, which is driven by an electric motor 34. The electric motor 34 is controlled by the control unit 18 by means of pulse width modulated signals. Downstream of the heating pump 32, the heating circuit line 30 leads to an exhaust gas recirculation heat exchanger 36. The exhaust gas recirculation heat exchanger 36 is connected in series is a heating heat exchanger 38. Starting from the heating heat exchanger 38, the heating circuit line 30 then leads to the main line 24, which leads to the coolant pump 26.

The vehicle radiator 22 is provided with a radiator blind 40, which can be adjusted by means of an electric motor 42, and a fan 44, which is driven by means of an electric motor 46. By actuating the electric motors 42 and 46, an adjustment of the radiator blind 40 or a speed of the fan 44 can be changed by means of the control device 18.

The central control unit 18 receives input signals from a coolant temperature sensor 48 and a land temperature sensor 50 in the internal combustion engine 10. The coolant temperature sensor 48 measures a temperature of the coolant at the outlet 12 of the internal combustion engine 10 and the land temperature sensor 50 measures a temperature of a material area between the exhaust valves of the internal combustion engine 10 A connection 52 shown in dashed lines illustrates a data exchange between the internal combustion engine 10 and the central control unit 18. By means of a data exchange via the connection 52, the central control device 18 receives actual values of operating parameters of the internal combustion engine 10, and sets manipulated variables for the operation of the internal combustion engine 10, for example the injection quantity, throttle valve position, ignition timing and the like. In addition, the central control unit 18 receives input signals from a block 54 which relate to heating and air conditioning requirements. If, for example, an increased air conditioning output is requested from block 54, control unit 18 can increase an engine load on the one hand and take measures on the other to be able to dissipate the then increased amount of heat via the coolant circuit.

In order to enable engine cooling to meet requirements, a control structure is implemented in the control unit 18, with which, depending on the coolant temperature and others, a control structure is implemented Operating parameters of the internal combustion engine 10, the mixing valve 14, the coolant pump 26, the heating pump 32, the radiator blind 40, the fan 44 and possibly an injection system of the internal combustion engine 10 can be controlled differently. For this purpose, several states of the system comprising the internal combustion engine 10 and the coolant circuit are defined, in each of which different measures for regulating the coolant temperature or the web temperature are taken.

The control structure implemented in the control unit 18 is constructed in such a way that it can be adapted to different internal combustion engines 10 and / or additional requirements for operation with little effort. In the example shown in FIG. 1, the requirements of block 54 regarding heating and air conditioning requirements are additionally processed.

The central control device 18 is shown schematically in the illustration in FIG. 2. 2 serves to clarify the input variables available to the control unit 18 and the signals output as part of the control of the coolant and component temperature of the internal combustion engine 10. A coolant temperature T _κ from the coolant temperature sensor 48 and a component temperature T _B from the web temperature sensor 50 are fed to the control device 18. In addition, the control unit 18 has the current engine speed n and a current injection quantity rrie available. The control of the coolant and component temperature on the basis of these input variables T _κ , T _B , n and never is explained in detail with reference to FIG. 3.

The control unit 18 also has an outside air temperature T _AL , a charge air temperature T _LL , an exhaust gas recirculation rate AGR, the already mentioned climate requirements K, a vehicle speed v and an accelerator pedal position p available as input variables. These input variables are used to determine a state of the system from internal combustion engine 10 and to determine the coolant circuit, different measures being taken in the individual states in order to regulate the coolant and component temperature. After determining the system state, a coolant volume flow requirement is determined for the control, which is represented by block 60. The volume flow requirement 60 is converted into a manipulated variable 62 for the setting of the heating pump 32 and a manipulated variable 64 for the setting of the coolant pump 26.

In addition, a rotary slide valve positioning 66 is requested, which is converted into a manipulated variable 68 for the setting of the mixing valve 14.

Finally, a cooling air mass requirement 70 is determined, which is set in a manipulated variable 72 for controlling the radiator blind 40 and in a manipulated variable 74 for controlling the fan 44.

3 shows the determination of the manipulated variables in accordance with the method according to the invention in more detail. The determination of a manipulated variable is described using the controller for the coolant pump 26. A basic characteristic map 80 is used to determine a basic value for a required volume flow of the coolant on the basis of the input quantities injection quantity m _e and engine speed n. This basic value from block 80 is transferred to a block 82, in which a hysteresis characteristic is applied to this basic value in order to prevent uncontrolled switching in transition areas. A volume flow request is thus available at the output of block 82 and is transferred to the link units 84 and 86. The determined basic value of the volume flow is corrected using the linking units. In the linking unit 84, the basic value is corrected by means of a controller which uses the coolant temperature T _κ as a reference variable and by means of the linking unit 86 the basic value is corrected by means of a controller. rigged, which uses the component temperature T _B as a reference variable.

To determine the correction value, a setpoint T _Kso ιι for the coolant temperature as a function of the current injection quantity m _{^ of} the current engine speed n is specified by a block 88. The target value T _Kso ιι is transferred to a linking unit 90, which also the current actual value of the coolant temperature T _K ι _{st is available} from the coolant sensor 48 and which determines a control difference from these values. The control difference determined in this way is transferred to a block 92, in which a hysteresis characteristic curve is applied to the control difference determined. Block 92 thus transfers a correction value for the volume flow request to the linking unit 84 and adds it there to the previously determined basic value.

Similarly, in order to take into account the component temperature T _B , a setpoint T _B soiι is first determined in a block 94 on the basis of a basic map, taking into account the injection quantity m _e and the engine speed n, and in a linking unit 96 from an actual value T _B i _st and the setpoint T _B s _o iι determined a control difference. A hysteresis characteristic curve is applied to the determined control difference in block 98, so that a correction value for a volume flow request is transferred from block 98 to the linking unit 86. Parallel to the application of the hysteresis characteristic in block 98, a temporal change in the component temperature is taken into account in block 100 in order to achieve a satisfactory regulation of the component temperature which is more dynamic compared to the coolant temperature. The volume flow request issued by block 100 is also supplied to the linking unit 86.

Both the volume flow request from block 84 and the volume flow request from block 86 are combined in one Blocks 102 and 104 are checked to determine whether they exceed a maximum or minimum applicable value and, if necessary, limit them to these values.

The volume flow requests are then transferred from blocks 102 and 104 to a max-linking unit 106. In the max logic unit 106, it is checked which of the volume flow requests from block 102 or from block 104 is larger, and only the larger volume flow request is passed to block 108, in which a conversion characteristic is applied to the volume flow request. As a result, the volume flow requirement is converted into a control signal for the coolant pump 26, which is finally amplified by means of an output stage 110 and passed on to the coolant pump 26.

3 can be changed in a simple manner in order to adapt the control to different internal combustion engines and / or different additional devices and requirements. For example, the basic map 80 can be changed to match different internal combustion engines. As a result, fundamentally different volume flow requirements could be achieved even without changing the controller taking the coolant temperature T _κ or the component temperature T _B into account. The control structure shown in FIG. 3, which can be used in the same way for the determination of manipulated variables for the control of the mixing valve 14, the radiator blind 40, the fan 44, the heating circuit pump 32 and optionally the injection system of the internal combustion engine 10, is thereby simpler Adaptable to different engines.

In addition, additional requirements can also be integrated through the control structure shown in FIG. 3. For this purpose, the Max logic unit 106 creates an interface into which further requirements can be fed. The max link 106 gives the those regulators have access to the actuators of the coolant pump 26, the heating circuit pump 32, the mixing valve 14, the fan 44 or the radiator blind 40, which transfers the greatest demand value to the max logic unit 106. Further requirements, for example from a climate control system or from a cooling of the exhaust gas recirculation required at a special operating point, can thus be fed into the maximum link 106, which ensures that these requirements are taken into account when determining the manipulated variables.

As has already been discussed in connection with FIG. 2, the central control unit 18 uses the input variables available to it to determine which predetermined state the system of internal combustion engine 10 and coolant circuit is currently in. In the preferred embodiment of the invention, seven states are predefined which the system of internal combustion engine 10 and coolant circuit can assume and in which different measures are provided in order to achieve control of the coolant temperature and the land temperature.

These seven possible states or stages in the heat management control according to the invention are described below with reference to FIG. 4. The overview of FIG. 4 shows in a column in each case the conditions for a certain state or a certain level to be assumed, as well as the measures taken in the respective state.

A first state corresponds to a cold start, in which a component temperature is in the range from -20 ° C to 120 ° C and a coolant temperature at the outlet from the internal combustion engine is in the range from -20 ° C to 80 ° C. A temperature of the charge air after a charge air cooler is less than 60 ° C and a pressure of a refrigerant in an air conditioning circuit is below 12 bar. For example, there are low Ambient temperatures in the range of -20 ° C. In this first state, the objective is to accelerate the warm-up of the internal combustion engine 10 and to reach an acceptable interior temperature as quickly as possible. For this purpose, the volume flow flowing through the heating pump 32 is regulated by means of the motor 34 via the central control unit 18. This also flows through the exhaust gas recirculation heat exchanger 36 and the heating heat exchanger 38, so that a rapid heating of the interior can be expected. The magnetic coupling 28 of the coolant pump 26 is decoupled, so that the coolant pump 26 is only passed passively but does not itself contribute to the promotion of a volume flow. The mixing valve 14 is set in the first state such that the bypass line 18 is completely open and the line leading to the cooler 22 is completely closed. The radiator blind 40 is completely closed, the fan 44 is switched off and an air conditioning compressor is also switched off. A so-called cook protection, which, when used, reduces the power of the internal combustion engine in order to reduce the amount of heat generated, is switched off.

In a second state, which, like the first state, is associated with a warm-up of the internal combustion engine and in which the interior is to be heated, the cooling water and the web between the exhaust valves are already heated. In detail, the state of the system is classified by the control device 18 in the second state when low ambient temperatures, for example -20 ° C., a land temperature in the range from 120 ° C. to 160 ° C., a temperature at the cooling water outlet 12 in the range of 80 ° C. up to 90 ° C, a charge air temperature after the charge air cooler is less than 60 ° C and a refrigerant pressure of less than 12 bar. In this second state, in order to heat up the interior as quickly as possible, the heating pump 32 is switched on and supplies 100% of the possible volume flow. As a result, the exhaust gas recirculation cooler 36 and the heating heat exchanger 38 have a maximum flow. The coolant pump 26 is switched on or off by optional switch the magnetic coupling on or off. This takes place depending on the coolant or web temperature. The mixing valve 14 is set in the second state such that the bypass line 18 is fully open and the line leading to the cooler 22 is completely closed. The radiator blind 44 and possibly further blinds in front of the charge air cooler and a condenser are closed. The electric fan 44, the air conditioning compressor and the cook protection are switched off.

A change to a third state occurs when the internal combustion engine is already warm from operation and the land temperature and the coolant temperature are in the desired range. In the third state, heating in the vehicle interior is still required. Specifically, the system assumes the third state when low ambient temperatures, for example -20 ° C, a land temperature in the range from 140 ° C to 180 ° C, a coolant temperature at the outlet 12 in the range from 90 ° C to 95 ° C, a Charge air temperature of less than 60 ° C and a refrigerant pressure of less than 12 bar. In this third state, the heating pump 32 is switched on and supplies 100% of its possible volume flow. The coolant pump 26 is switched on because the magnetic clutch 28 is not energized. The mixing valve 14 is operated in regular operation and consequently conducts the coolant flow depending on the coolant temperature at the coolant sensor 48 and the land temperature at the component sensor 50 through the bypass line 18 and / or to the cooler 22. Since the mixing valve 14 is designed as a rotary slide valve, each Distribution of the coolant to the bypass line 18 and the cooler 22 can be set continuously in control operation. As in states one and two, the radiator blind 40 and any other blinds are closed, the fan 44, the air conditioning compressor and a cooker protection are switched off.

If the internal combustion engine 10 is heated further, a change is made to a fourth state in which the operating temperature already lie at the top of the target range. In this fourth state, too, the vehicle interior must be heated due to low ambient temperatures. Specifically, the fourth state is characterized by a land temperature in the range from 160 ° to 200 ° C, a coolant temperature from 95 ° C to 100 ° C, a charge air temperature after the charge air cooler of more than 60 ° C and a refrigerant pressure of less than 12 bar , In this fourth state, the heating pump 32 is switched on and supplies 100% of its possible volume flow. The coolant pump 26 is switched on because the magnetic coupling 28 is not energized. The mixing valve 14 assumes an end position, closes the bypass line 18 completely and directs the coolant flow completely to the vehicle radiator 22. The radiator blind 40 and possibly further blinds are regulated as a function of the coolant temperature and the web temperature. The fan 44, the air conditioning compressor and the cook protection are switched off.

The system changes to a fifth state when there are higher ambient temperatures, for example around 20 ° C., so that heating in the vehicle interior is no longer necessary but also no air conditioning is necessary. The fifth state is characterized by web temperatures in the range of 160 ° C to 200 ° C, coolant temperatures between 100 ° C and 115 ° C, charge air temperatures of more than 60 ° C and a refrigerant pressure of less than 12 bar. In the fifth state, the heating pump 32 is switched off, the coolant pump 26 is switched on and the mixing valve 14 closes the bypass line 18 and directs the coolant flow completely to the cooler 22. The cooler blind 40 and optionally further blinds in front of the charge air cooler and the condenser are fully open. The fan 44 is regulated depending on the coolant temperature and the web temperature. The air conditioning compressor and the cook protection are switched off. If the ambient temperature continues to rise, the interior becomes air-conditioned and the system changes to a sixth state. Specifically, the sixth state is due to ambient temperatures in the range from 20 ° C to 30 ° C, land temperatures in the range from 160 ° C to 200 ° C, coolant temperatures in the range from 100 ° C to 115 ° C, charge air temperatures of more than 60 ° C and a refrigerant pressure in the range of 12 bar to 20 bar. In this state, the system still tries to meet all requirements with regard to engine performance and climate performance and mobilizes all reserves that are available for heat dissipation from the internal combustion engine 10. The heating pump 32 is switched off, while the coolant pump 26 is switched on. The mixing valve 14 keeps the bypass line 18 closed and directs the coolant flow completely to the cooler 22. The cooler blind 40 and any other blinds are fully open. The fan 44 runs at maximum power and thereby enables a maximum air throughput through the cooler 22. The air conditioning compressor is regulated as a function of the desired interior temperature. The cook protection is switched off.

With a further increase in the ambient temperatures and / or unfavorable boundary conditions, such as high engine power and low driving speed, the operating temperatures of the engine can continue to rise and into the critical range. In this seventh state, measures must therefore be taken to protect the internal combustion engine 10 from thermal damage. Specifically, the seventh state is due to a high ambient temperature, for example between 30 ° C and 35 ° C, a land temperature in the range 160 ° C to 200 ° C, a coolant temperature in the critical range of more than 115 ° C, a charge air temperature of more than 60 ° C and a refrigerant pressure of more than 20 bar. All reserves for heat dissipation are mobilized and the heating pump 32 is switched off, the coolant pump 26 is switched on, the mixing valve closes the bypass line 18 completely and conducted the coolant flow completely to the cooler 22, the cooler blind 40 and possibly further blinds are fully open and the fan 44 runs at maximum power. In order to prevent a further rise in temperature, the air conditioning compressor is operated with reduced output and at the same time a reduced motor output is set via the cook protection. This can be done, for example, by reducing an injection quantity. If the operating temperatures drop, the system can switch back to the sixth state and the full engine and air conditioning performance is available again.

If not all boundary conditions for a certain level or a certain state are fulfilled, prioritization can take place such that the system assumes a certain state if selected operating parameters lie within a range defined for this state.

Claims

claims

1. Method for regulating the heat of an internal combustion engine for vehicles with a coolant circuit and controllable devices for influencing the heat balance of the internal combustion engine (10), wherein a coolant temperature and further operating parameters of the internal combustion engine (10) are recorded and the controllable devices (14, 26, 32, 40 , 66) are controlled as a function of the coolant temperature and the further operating parameters of the internal combustion engine (10), characterized in that the coolant temperature and / or the further operating parameters are regulated in such a way that on the basis of at least two different reference variables (T _κ , T _B ) at least two output values for determining a manipulated variable for the controllable devices (14, 26, 32, 40, 44) are determined, the at least two output values are compared and the larger output value is converted into the manipulated variable and sent to the controllable devices (14, 26, 32 . 40, 44) is passed.

2. The method, in particular according to claim 1, for thermoregulating an internal combustion engine for vehicles with a coolant circuit and controllable devices for influencing the heat balance of the internal combustion engine (10), wherein a coolant temperature and other operating parameters of the internal combustion engine (10) are recorded and the controllable devices (14 , 26, 32, 40, 44) are controlled as a function of the coolant temperature and the further operating parameters of the internal combustion engine (10), characterized in that the coolant temperature and / or the further operating parameters are controlled in such a way that an output value for determining a manipulated variable is specified by means of a basic map (80) as a function of the speed and load of the internal combustion engine and this output value is determined as a function of a controller the coolant temperature and / or the other operating parameters is corrected.

3. The method according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t, that a hysteresis characteristic curve (82, 92, 98) is used in the determination of a manipulated variable.

4. The method according to any one of the preceding claims, characterized in that a determination of target values of a coolant temperature (T _RSOI I) and a component temperature (T _Bso ιι) of the internal combustion engine (10) by means of maps (88, 94) as a function of a speed and an injection quantity the internal combustion engine (10).

5. The method according to any one of the preceding claims, characterized in that several states of the system of internal combustion engine (10) and coolant circuit are defined, each associated with different values of the coolant temperature and / or the other operating parameters and in which the controllable devices (14, 26th , 32, 40, 44) for controlling at least the coolant temperature are at least partially controlled differently.

6. The method according to any one of the preceding claims, characterized in that a change in the various states by exceeding or falling below predetermined limits of an ambient temperature temperature, a component temperature of the internal combustion engine, a coolant temperature, a charge air temperature and / or a pressure of an air conditioning compressor is triggered and in the individual states for controlling a coolant temperature and a component temperature of the internal combustion engine (10) the settings of a coolant pump (26), a heating pump (32 ), a mixing valve (14) between a cooler and a bypass circuit, a radiator blind (40), a radiator fan (44), an air conditioning compressor and / or an injection system of the internal combustion engine (10) can be changed.