Method for operating an internal combustion engine of a motor vehicle and motor vehicle

Abstract

The invention relates to a method for operating an internal combustion engine of a motor vehicle, in which at least one value is determined by means of an electronic computing device, which characterizes a current and / or future deposit on at least one component of the internal combustion engine (step S1). A comparison is carried out in which the value is compared with a reference value (step S2). Depending on the result of the comparison, a switch is made from a first operating strategy, according to which the internal combustion engine is operated by means of the electronic computing device for a first period of time, to a second operating strategy that differs from the first operating strategy, according to which the internal combustion engine is operated by means of the electronic computing device for a second period of time (step S3).

Description

[0001] The invention relates to a method for operating an internal combustion engine of a motor vehicle. The invention also relates to a motor vehicle.

[0002] US 9 534 551 B2 discloses a machine. Furthermore, JP 6 025 896 B2 discloses an exhaust system as known. DE 10 2010 003 305 B4 discloses a method for preventing irregular combustion in an internal combustion engine. DE 60 2005 002 659 T2 discloses a system for evaluating the soot charge state in cleaning agents. DE 10 2018 106 822 A1 discloses a regeneration method for reducing the degree of coking of an annular gap surrounding an injector. DE 10 2016 200 952 A1 discloses a method for operating an internal combustion engine. DE 10 2012 217 203 A1 discloses a machine.

[0003] The object of the present invention is to create a method and a motor vehicle such that a particularly advantageous operation of an internal combustion engine can be realized.

[0004] The problem is solved according to the invention by a method with the features of claim 1 and by a motor vehicle with the features of claim 6. Advantageous embodiments of the invention are the subject of the dependent claims.

[0005] A first aspect of the invention relates to a method for operating an internal combustion engine, also referred to as a combustion engine or motor, and preferably designed as a reciprocating engine, i.e., a reciprocating piston motor, of a motor vehicle. This means that the motor vehicle, also simply referred to as a vehicle and preferably designed as a motor car, in particular a passenger car, in its fully manufactured state has the internal combustion engine and can be driven by means of the internal combustion engine. For example, in the method, the motor vehicle is driven by means of the internal combustion engine.

[0006] In this process, an electronic computing device is used to determine at least one value, also referred to as the deposit value. Unless otherwise specified, the term "value" refers to the deposit value. This value characterizes current and / or future deposits on at least one component of the internal combustion engine. These deposits include, for example, soot deposits on the at least one component, also known as carbon buildup or coking.

[0007] In this process, a comparison is performed using the electronic computing device, in which the value is compared with a reference value. Depending on the result of the comparison, the system switches, particularly by means of the electronic computing device, from a first operating strategy, according to which the internal combustion engine, particularly in its fired operation, is operated by the electronic computing device for a first period of time, to a second operating strategy that differs from the first operating strategy, according to which the internal combustion engine, particularly in its fired operation, is operated by the electronic computing device for a second period of time, particularly following the first period of time.In the fired operation of the internal combustion engine, combustion processes take place within the engine, particularly in the combustion chambers, such that within each operating cycle of the engine, one of the combustion processes takes place in the respective combustion chamber. In each combustion process, a fuel-air mixture, also referred to simply as a mixture, is combusted, in particular ignited and burned, wherein the mixture comprises at least air and a fuel, in particular a liquid or gaseous fuel, by means of which the internal combustion engine can be operated, or is operated, particularly in the fired operation. Preferably, the internal combustion engine is a spark-ignition engine, in particular a gasoline engine.In particular, the system switches from the first to the second operating strategy when the comparison shows that the value exceeds the reference value, or when the difference between the value exceeding the reference value and the reference value is greater than a predefined or predetermined threshold. This change in operating strategy, i.e., switching from the first to the second, can, for example, counteract deposit formation, prevent an increase in deposit formation, or, especially if the value characterizes future deposit formation, prevent excessive deposit formation on at least one component. Thus, the process can prevent excessive deposit formation on at least one component even over a long service life and / or operating period.This ensures a particularly advantageous, especially a particularly efficient and therefore fuel-efficient, operation of the internal combustion engine.

[0008] A first embodiment of the invention is characterized in that the value is determined as a function of at least one environmental parameter characterizing the environment of the motor vehicle, which allows for particularly advantageous conclusions to be drawn about current or future deposition. Subsequently, a particularly advantageous operating procedure can be described. One of the environmental parameters comprises the ambient humidity.

[0009] An alternative or additional variant of the invention is characterized in that the value is determined as a function of at least one operating parameter, which characterizes a past and / or current operation, in particular a fired operation, of the internal combustion engine. This allows for particularly accurate predictions of future or current deposit formation, thus enabling the representation of a particularly advantageous operating mode. To enable particularly advantageous determination of the value or deposit formation, the operating parameter comprises a time-dependent profile of at least one valve stroke of a gas exchange valve of the internal combustion engine.

[0010] In order to operate the internal combustion engine particularly advantageously, one embodiment of the invention provides that the value is determined as a function of a driving profile of at least one person driving the motor vehicle.

[0011] In order to be able to draw particularly advantageous conclusions about current or future deposition, so that advantageous operation of the internal combustion engine can subsequently be ensured, it is provided in a further embodiment of the invention that the environmental parameter includes a temperature of the environment, also referred to as ambient temperature.

[0012] Another embodiment is characterized, for the realization of a particularly advantageous operation of the internal combustion engine, by the fact that the value is determined as a function of at least one fuel parameter, which characterizes the fuel, in particular a quality and / or a state of the fuel, with which the internal combustion engine is operated, in particular in the fired operation.

[0013] To determine the value or the deposit particularly advantageously, a further embodiment of the invention provides that the operating parameter includes a composition of the mixture with which the internal combustion engine is operated, and / or a composition of the exhaust gas from the internal combustion engine, the exhaust gas resulting from the respective combustion of the respective mixture. Alternatively or additionally, the operating parameter includes a time profile of a control of the air-fuel ratio (also referred to as lambda), also referred to as combustion control, by means of which the internal combustion engine is operated, and / or a time profile of the load of the internal combustion engine, and / or a time profile of the rotational speed of the internal combustion engine.

[0014] A second aspect of the invention relates to a motor vehicle, also referred to simply as a vehicle, and preferably configured as a motor car, in particular as a passenger car, which is configured to carry out a method according to the first aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention and vice versa.

[0015] The invention is based in particular on the following findings and considerations: For example, depending on the driving profile, ambient and / or environmental conditions, and the fuel used, deposits such as carbon deposits can form in the combustion chamber and / or on adjacent components such as spark plugs, injectors, valves, valve seats, pistons, piston rings, combustion chamber walls, etc., during operation of an internal combustion engine, such as a gasoline engine. Such deposits can be detected or identified, for example, by evaluating engine control parameters. For this purpose, the temporal profile of the valve lift, and thus the temporal profile of a variable valve lift adaptation in an internal combustion engine, particularly the intake lift, mixture adaptation values, and / or information from the combustion control system can be evaluated.These parameters can be used individually or in combination to generate a statement about deposit buildup and / or deposit state. Deposit buildup refers specifically to future deposit formation, that is, the future development of the deposit. Deposit state refers specifically to the current deposit. This allows for a kind of digital detection of whether or not excessive deposits are present on at least one component. Furthermore, continuous deposit detection is possible, enabling not only a qualitative statement about the deposits on the at least one component, but also a quantitative statement about the deposits on the component.

[0016] Excessive deposits can lead to combustion disturbances, particularly during idling and / or near-idle operation. Especially during idling and near-idle operation, excessive deposits can cause vibrations or undesirable excitations, particularly due to increased combustion stochasticity resulting from the deposits. This deterioration can occur over time or across cycles in the same combustion chamber and / or vary across different combustion chambers.

[0017] The method according to the invention is, or enables, a preventive strategy. For the operation of the internal combustion engine, a preventive strategy is proposed to reduce or prevent excessive deposits. If, for example, the value—and thus, for example, the driving profile, the ambient and / or environmental conditions, and / or the currently used fuel—is deemed critical for the formation of deposits, at least one measure or measures, individually or in combination, are activated that reduce, prevent, or even enable the removal of deposits. Different levels of intensity of the respective measures are also possible.These measures can include different combinations of combustion-determining parameters such as injection timing, quantity, and distribution, charge motion, intake stroke control, ignition timing, valve timing, and / or residual gas quantity, and / or a change in the air-fuel ratio at which the internal combustion engine operates. Alternatively or additionally, an operating point adjustment can be performed, for example, by requesting a gear shift or increasing the load point, to operate the internal combustion engine more frequently than before at operating points where deposits are less likely to form or can even be reduced. These measures can be applied individually or in combination. For example, the measures can be requested and initiated in a workshop using a diagnostic tool to reduce or remove existing deposits.

[0018] Alternatively or additionally, a strategy based on the current, determined, and therefore known deposit state is possible. Taking into account the current deposit state and thus the actual deposit state of the internal combustion engine, a deposit-optimized strategy can be implemented. The measures taken, specifically depending on the current deposit state, can delay further buildup, prevent further buildup, or even reduce deposits, in the same way as described above, and thus, for example, influence the combustion parameters and / or shift the operating point. For this purpose, the inventive method involves switching from the first operating strategy to the second operating strategy.

[0019] Further details of the invention will become apparent from the following description of a preferred embodiment with the accompanying drawing. The only illustration shown is... Fig. 1. A block diagram illustrating a method for operating an internal combustion engine.

[0020] The only Fig.Figure 1 shows a block diagram, which is used below to describe a method for operating an internal combustion engine of a motor vehicle. The method is carried out using an electronic computing device, in particular in the motor vehicle. In a first step S1 of the method, at least one value, also referred to as a deposit value, is determined by the electronic computing device. This value characterizes a current and / or future deposit on at least one component of the internal combustion engine. The deposit is, or includes, for example, a deposit of soot on the at least one component, where the deposit of soot is also referred to as carbon buildup or coking.

[0021] In a second step S2 of the procedure, a comparison is carried out using the electronic computing device, in which the deposition value is compared with a reference value.

[0022] In the method, the internal combustion engine is operated, in particular controlled or regulated, by means of the electronic computing device during a first period of time according to a first operating strategy, wherein during the first period the internal combustion engine is operated in its fired operation according to the first operating strategy by means of the electronic computing device.

[0023] In a third step S3 of the process, depending on the result of the comparison, the system switches from the first operating strategy to a second operating strategy that differs from the first. According to this second strategy, the internal combustion engine is operated under fired conditions by means of the electronic computing unit for a second period of time. The second operating strategy differs from the first operating strategy, for example, in its combustion parameters and thus in its combustion control. The combustion parameters that characterize the combustion control define the combustion of mixtures that are burned in the internal combustion engine during fired operation. Thus, the combustion control influences the combustion of the mixtures.In particular, the operating strategies differed in such a way that operating the internal combustion engine according to the second operating strategy reduced deposit formation from the combustion of the mixtures, prevented an increase in deposit formation, or slowed the rate of deposit formation compared to operating the internal combustion engine according to the first operating strategy. This ensures efficient and therefore fuel-efficient operation of the internal combustion engine even over a long service life and / or operating period.

Claims

[1] Method for operating an internal combustion engine of a motor vehicle, wherein: - by means of an electronic computing device, at least one value is determined which characterizes a current and / or future deposit on at least one component of the internal combustion engine (step S1); - a comparison is carried out using the electronic computing device, in which the value is compared with a reference value (step S2); and - depending on the result of the comparison from a first operating strategy, according to which the internal combustion engine is operated by means of the electronic computing device during a first period of time, to a second operating strategy different from the first operating strategy, according to which the internal combustion engine is operated by means of the electronic computing device during a second period of time (step S3);characterized by , that: - the value is determined as a function of at least one environmental parameter characterizing the environment of the motor vehicle, wherein the environmental parameter includes ambient humidity; and / or - the value is determined as a function of at least one operating parameter which characterizes a past and / or current operation of the internal combustion engine, wherein the operating parameter comprises a time course of at least one valve stroke of a gas exchange valve of the internal combustion engine. [2] Method according to claim 1, characterized by that the value is determined depending on the driving profile of at least one person driving the motor vehicle. [3] Method according to claim 1 or 2, characterized by , that the environmental parameter includes the temperature of the environment. [4] Method according to any one of the preceding claims, characterized by, that the value is determined as a function of at least one fuel parameter which characterizes a fuel with which the internal combustion engine is operated. [5] Method according to any one of the preceding claims, characterized by , that the operating parameter includes: - a composition comprising at least one mixture including air and a fuel, with which the internal combustion engine is operated; and / or - a composition of an exhaust gas from an internal combustion engine; and / or - a time course of a control of a combustion air ratio with which the internal combustion engine is operated; and / or - a time course of a load on the internal combustion engine; and / or - a time course of the rotational speed of the internal combustion engine. [6] Motor vehicle designed to carry out a method according to any of the preceding claims.

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