초록 ▼

The invention relates to a fuel injection system having an electrically actuatable injection pump which comprises a pre-stroke actuator for setting the start of injection and a flow rate actuator for setting the injection quantity. A control unit for controlling the injection quantity and start of i

The invention relates to a fuel injection system having an electrically actuatable injection pump which comprises a pre-stroke actuator for setting the start of injection and a flow rate actuator for setting the injection quantity. A control unit for controlling the injection quantity and start of injection emits an actuation signal which starts injection to the flow rate actuator, and an actuation signal for the start of injection to the pre-stroke actuator via an output lead for the actuation signal for the start of injection. According to the invention, the control unit protects the pre-stroke actuator against a short-circuit on the output lead by monitoring the control deviation at the start of injection between the actual value for the start of injection (detected by means of a needle movement sensor) and a desired value for the start of injection, which fixed as a function of the engine operating point. The unit takes protective measures if the control deviation at the start of injection is greater than a prescribable warning threshold value for longer than a prescribable time period.

대표청구항 ▼

[ What is claimed is:] [1.] Internal combustion engine fuel injection system having an electrically actuatable injection pump with a pre-stroke actuator for setting the start of injection and a control unit for controlling start of injection, which control unit emits an actuation signal for the star

[ What is claimed is:] [1.] Internal combustion engine fuel injection system having an electrically actuatable injection pump with a pre-stroke actuator for setting the start of injection and a control unit for controlling start of injection, which control unit emits an actuation signal for the start of injection to the pre-stroke actuator via an output lead, said fuel injection system further comprising:a needle movement sensor for detecting an actual start of injection based on movement of a needle for controlling fuel flow in said fuel injection system;a comparing device for comparing said actual start of injection with a desired start of injection, to generate a start-of-injection control deviation value; andmeans in said control unit for protecting the pre-stroke actuator against a short circuit on said output lead, by monitoring said start-of-injection control deviation, detecting when said start-of-injection control deviation exceeds a predeterminable warning threshold value for a time which is longer than a predeterminable time interval, and generating an error detection signal in response thereto.