Method and device for operating an injection system for an internal combustion engine

A device for operating an injection system for an internal combustion engine having a prefeed pump for conveying fuel out of a fuel tank and having a high pressure pump which is arranged downstream of the prefeed pump for conveying the fuel into a fuel accumulator,

• the device being configured to:
• determine, as a function of a pilot control characteristic diagram, prefeed value which is a function of at least one operating variable of the internal combustion engine,
• initialize a correction value for the prefeed pump with a safety value which is predefined in such a way that deviations from a predefined conveying behavior of the prefeed pump which lie within a predefined tolerance range are compensated for in such a way that a sufficient delivery performance of the prefeed pump is ensured,
• actuate the prefeed pump as a function of the prefeed value and the correction value, and
• to adaptat the correction value with regard to its effect to the conveying behavior of the prefeed pump as a function of a variable of the injection system, the value or value profile of which variable is representative for whether a desired pressure can be achieved in the fuel accumulator, to be precise in the context of a reduction in the delivery performance of the prefeed pump as long as the value is representative for the fact that the desired pressure can be reached in the fuel accumulator.

An injection system for an internal combustion engine comprising a prefeed pump for conveying fuel out of a fuel tank, a high pressure pump which is arranged downstream of the prefeed pump for conveying the fuel into a fuel accumulator, and a control device being operable

• to determine, as a function of a pilot control characteristic diagram, a prefeed value which is a function of at least one operating variable of the internal combustion engine,
• to initialize a correction value for the prefeed pump with a safety value which is predefined in such a way that deviations from a predefined conveying behavior of the prefeed pump which lie within a predefined tolerance range are compensated for in such a way that a sufficient delivery performance of the prefeed pump is ensured,
• to actuate the prefeed pump as a function of the prefeed value and the correction value, and
• to adaptat the correction value with regard to its effect to the conveying behavior of the prefeed pump as a function of a variable of the injection system, the value or value profile of which variable is representative for whether a desired pressure can be achieved in the fuel accumulator, to be precise in the context of a reduction in the delivery performance of the prefeed pump as long as the value is representative for the fact that the desired pressure can be reached in the fuel accumulator.