Patent ID: 9140223
Filing Date: 2015-09-22
Classification: F02D,F02M

Abstract:
1. A fuel injection system, with high operational repeatability and stability, for an internal combustion engine, comprising: at least one fuel injector to be controlled by a metering servo valve, the at least one fuel injector including a control chamber to be supplied with fuel and including an outlet passage to be opened or closed by an open/close element cooperating with a corresponding valve seat; an urging member to urge the open/close element into engagement with the valve seat in a valve closing position; an electric actuator including an armature to act on the open/close element against the action of the urging member to open the outlet passage; and a control circuit to control the electric actuator to supply, in a fuel injection phase, at least a first electric command to actuate the open/close element to inject a pilot fuel injection, and a second electric command to actuate the open/close element to inject a main fuel injection, the first and second electric commands separated in time by an electric dwell time chosen to cause the main fuel injection to start without a solution of continuity with the pilot fuel injection; wherein the open/close element initially engages the armature as the open/close element is urged into engagement with the valve seat by the urging member to urge the armature toward a closed position, the open/close element releasing the armature as the armature moves toward the closed position such that the armature impacts the open/close element after the open/close element engages the valve seat to limit rebounding of the open/close element from engagement of the open/close element to the valve seat such that an amount of fuel injected during the pilot and main fuel injections in a fuel injection phase is substantially constant during the electric dwell time.