Fuel-supply system for an internal combustion engine

1. A method for operating a fuel supply system of an internal combustion engine, wherein the fuel supply system includes a pump having an outlet coupled to a high-pressure region including a fluid accumulator, wherein a normal operating pressure of the high-pressure region is between 200 bar and 350 bar, and a pressure-limiting valve having an inlet coupled to the high-pressure region including the fluid accumulator, the method comprising:

when the internal combustion engine is set into a deactivated state, actuating the pump such that, at the outlet side of the pump, a pressure is increased in the high-pressure region including the fluid accumulator to a sufficient extent that the pressure-limiting valve is opened by the pressure in the high-pressure region acting on the inlet of the pressure-limiting valve; and

monitoring a pressure at the outlet of the pump and ceasing actuation of the pump when the pressure exceeds a predefined opening threshold of the pressure-limiting valve;

wherein the pressure limiting valve has an opening pressure less than 90 bar above the normal operating pressure of the high-pressure region and a closure threshold between 50 bar and 150 bar.

2. The method as claimed in claim 1 , wherein the pressure-limiting valve comprises a direct-acting safety valve.

3. The method as claimed claim 1 , wherein the pressure-limiting valve connects the outlet of the pump to a low-pressure region of the fuel supply system at the inlet side of the pump.

4. The method as claimed in claim 1 , wherein the pressure-limiting valve connects the outlet side of the high-pressure pump to a stroke chamber of the pump.

5. The method as claimed in claim 1 , wherein a predefined closure threshold of the pressure-limiting valve is between 90 bar and 150 bar.

6. The method as claimed in claim 1 , wherein the fuel supply system includes a sensor generating a measurement signal representative of the pressure at the outlet side of the pump.

7. A fuel supply system of an internal combustion engine, the fuel supply system comprising:

a pump having an outlet coupled to a high-pressure region with a normal operating pressure in the high-pressure region between 200 bar and 350 bar;

a fluid accumulator arranged in the high-pressure region coupled to the outlet of the pump;

a pressure-limiting valve having an inlet coupled to an outlet of the pump and coupled to the high-pressure region including the fluid accumulator;

a sensor measuring a pressure at the outlet of the pump; and

wherein actuation of the pump continues after the internal combustion engine has been deactivated until the sensor measures a pressure at the outlet side of the pump exceeding a predetermined opening value of the pressure-limiting valve;

wherein the pressure limiting valve has an opening pressure less than 90 bar above the normal operating pressure of the high-pressure region and a closure threshold of between 50bar and 150 bar.

8. The fuel system as claimed in claim 7 , wherein the pressure-limiting valve comprises a direct-acting safety valve.

9. The fuel system as claimed in claim 7 , wherein the pressure-limiting valve connects the outlet of the pump to a relatively lower pressure region of the fuel supply system at the inlet side of the pump.

10. The fuel system as claimed in claim 7 , wherein the pressure-limiting valve connects the outlet side of the high-pressure pump to a stroke chamber of the pump.

11. The fuel system as claimed in claim 7 , wherein a predefined closure threshold of the pressure-limiting valve is between 90 bar and 150 bar.

12. The fuel system as claimed in claim 7 , wherein actuation of the pump is ended based at least in part on the measurement signal of the sensor.