METHOD FOR OPERATING AN INTERNAL COMBUSTING ENGINE, AND CORRESPONDING INTERNAL COMBUSTION ENGINE

Abstract

A method for operating an internal combustion engine having multiple cylinders. A warm-up operation is carried out after the internal combustion engine has been started, during which a speed of the internal combustion engine is limited to a limit value. The limit value is selected during the warm-up operation at least temporarily as a function of a starting temperature of the internal combustion engine.

Claims

10. (canceled)

11. A method for operating an internal combustion engine having multiple cylinders, wherein after the internal combustion engine has been started, a warm-up operation is carried out, during which a speed of the internal combustion engine is limited to a limit value, wherein the limit value during the warm-up operation is selected at least temporarily as a function of a starting temperature of the internal combustion engine.

12. The method according to claim 11, wherein during the warm-up operation, a cylinder charge of the cylinder is limited at least temporarily to a limit value.

13. The method according to claim 11, wherein the warm-up operation is only carried out when the starting temperature of the internal combustion engine is less than a minimum temperature.

14. The method according to claim 11, wherein the limit value at the beginning of the warm-up operation is set to a starting value selected as a function of the starting temperature of the internal combustion engine.

15. The method according to claim 11, wherein the limit value is increased during the warm-up operation starting from the starting value in the direction of an end value.

16. The method according to claim 11, wherein the end value is selected as a function of the starting temperature of the internal combustion engine.

17. The method according to claim 11, wherein the increase takes place linearly or in steps.

18. The method according to claim 11, wherein the increase takes place as a function of an amount of air supplied to the internal combustion engine and/or a further temperature of the internal combustion engine.

19. The method according to claim 11, wherein the warm-up operation is ended when the limit value reaches the end value and/or the amount of air supplied to the cylinders exceeds a threshold value.

20. An internal combustion engine having multiple cylinders, wherein after the internal combustion engine has been started, a warm-up operation is carried out, during which a speed of the internal combustion engine is limited to a limit value, wherein the internal combustion engine is designed to select the limit value during the warm-up operation at least temporarily as a function of a starting temperature of the internal combustion engine.

21. The method according to claim 12, wherein the warm-up operation is only carried out when the starting temperature of the internal combustion engine is less than a minimum temperature.

22. The method according to claim 12, wherein the limit value at the beginning of the warm-up operation is set to a starting value selected as a function of the starting temperature of the internal combustion engine.

23. The method according to claim 13, wherein the limit value at the beginning of the warm-up operation is set to a starting value selected as a function of the starting temperature of the internal combustion engine.

24. The method according to claim 12, wherein the limit value is increased during the warm-up operation starting from the starting value in the direction of an end value.

25. The method according to claim 13, wherein the limit value is increased during the warm-up operation starting from the starting value in the direction of an end value.

26. The method according to claim 14, wherein the limit value is increased during the warm-up operation starting from the starting value in the direction of an end value.

27. The method according to claim 12, wherein the end value is selected as a function of the starting temperature of the internal combustion engine.

28. The method according to claim 13, wherein the end value is selected as a function of the starting temperature of the internal combustion engine.

29. The method according to claim 14, wherein the end value is selected as a function of the starting temperature of the internal combustion engine.

30. The method according to claim 15, wherein the end value is selected as a function of the starting temperature of the internal combustion engine.

Description

[0028] In the following, the invention will be explained in greater detail with reference to the exemplary embodiments depicted in the drawings, without this restricting the invention. In the sole FIGURE

[0029] FIGURE shows a schematic illustration of an internal combustion engine.

[0030] The FIGURE shows a schematic illustration of an internal combustion engine 1, which has multiple cylinders 2 in the exemplary embodiment shown here. Each of the cylinders 2 has at least one inlet valve 3 and at least one outlet valve 4. Fresh gas can be supplied to the respective cylinder 2 from an intake tract 5 via each of the inlet valves 3, whereas exhaust gas can escape from the corresponding cylinder 2 through each of the outlet valves 4, namely in the direction of an exhaust tract 6. Downstream of the exhaust tract 6 there can be an exhaust gas purification device 8, which is fluidically connected to the outlet valves 4 via an exhaust gas line 7. The exhaust gas purification device 8 can, for example, have at least one catalytic converter.

[0031] The internal combustion engine 1 is operated by means of a method according to which a warm-up operation is carried out after the internal combustion engine has been started. The speed of the internal combustion engine 1 is limited to the limit value. Fresh gas is supplied to the cylinders 2 via the intake tract 5, wherein this fresh gas supply can additionally be limited to a limit value during the warm-up operation. In this respect, two limit values can thus exist, namely one for the speed of the internal combustion engine and one for the cylinder charge. The limit value or values are selected during the warm-up operation at least temporarily as a function of a starting temperature of the internal combustion engine 1.

[0032] For example, the internal combustion engine 1 is designed to determine the combustion chamber temperature at the time of the start of the internal combustion engine 1 in order to use this as the starting temperature. To determine the combustion chamber temperature, temperature sensors can be provided in the internal combustion engine 1. Additionally or alternatively, the combustion chamber temperature can be determined on the basis of a model calculation. The model calculation can calculate the combustion chamber temperature or the starting temperature using sensor data, such as an outside temperature, as well as the time curve of a standstill of the internal combustion engine 1 preceding the start of the internal combustion engine 1. If the measured or calculated starting temperature is below a minimum temperature, the warm-up operation is thus carried out.

[0033] At the beginning of the warm-up operation, the limit value is set to a starting value. During the warm-up operation, the limit value is increased starting from the starting value in the direction of an end value. The end value is selected, for example, so that the limit value of the speed reaches a maximum permissible speed which, in normal operation, may be present after the operating temperature has been reached, without damage to the internal combustion engine 1 occurring or being expected. In addition, a maximum permissible end value can also be defined for the limit value of the cylinder charge.

[0034] The limit value is increased in the direction of the end value, wherein the increase takes place as a function of the amount of air supplied cumulatively to the cylinders 2 via the intake tract 5 since the start. When the limit value reaches the end value, the warm-up operation is ended. Additionally or alternatively, it can be provided that the warm-up operation is ended as soon as the amount of air supplied cumulatively to the cylinders 2 since the start exceeds a threshold value. In this way, the internal combustion engine 1 is heated to an operating temperature in a controlled manner during the warm-up operation, and the pollutant emissions of the internal combustion engine 1 are accordingly significantly reduced during the warm-up operation.