Patent ID: 7997253

Claim:
A method for controlling the overpressure in a fuel-supply system of a common-rail type for an internal-combustion engine provided with a number of cylinders; the method comprising: supplying fuel under pressure, by means of a high-pressure pump, to a common rail connected to a number of injectors, each of which has a hydraulic actuation of the needle and absorbs for its actuation a flow rate (m BackFlow ) of fuel, which is discharged into an exhaust channel; detecting the effective value of the pressure of the fuel within the common rail; comparing the effective value of the pressure of the fuel within the common rail with a safety value of the pressure of the fuel within the common rail; determining a condition of emergency if the effective value of the pressure of the fuel within the common rail is higher than the safety value of the pressure of the fuel within the common rail; driving, in the case of emergency, the injectors for discharging part of the fuel present in the common rail without increasing the flow rate of fuel injected into the cylinders by increasing the flow rate (m BackFlow ) of fuel absorbed by the injectors for their actuation and without any supplementary opening so as to contain the increase in the pressure of the fuel within the common rail; deciding, in the case of emergency, whether in order to contain the increase in the pressure of the fuel within the common rail it is sufficient to increase the flow rate (m BackFlow ) of fuel absorbed by the injectors for their actuation; and driving, in the case of emergency, the injectors also for increasing a flow rate (m Inj ) of fuel injected into the cylinders with respect to the flow rate necessary for generation of the torque required by the engine control when it is not sufficient to increase the flow rate (m Backflow ) of fuel absorbed by the injectors for their actuation.