Electromagnetic fuel injector with braking device

摘要

The present invention relates to a fuel injector. The fuel injector is provided with an injection nozzle, an injection valve, and an electromagnetic actuator. The injection valve has a movable needle to adjust the flow of fuel through the injection nozzle. The electromagnetic actuator is adapted to move the needle between a closing position and an opening position of the injection valve and is provided with a movable plunger which is mechanically connected to the needle and has at least one feeding through hole for the passage of fuel towards the injection nozzle. The plunger is provided with a hydraulic type braking device, which is coupled to the feeding hole and hydraulically dissipates kinetic energy to slow down the opening stroke of the needle when the needle moves towards the opening position of the injection valve.

主权项

1. A fuel injector comprising:
an injection nozzle; an injection valve having a movable needle to adjust the flow of fuel through the injection nozzle; an electromagnetic actuator to move the needle between a closing position and an opening position of the injection valve, having at least one electromagnet including a coil, a fixed magnetic armature, and a movable plunger, which is mechanically connected to the needle and has at least one feeding through hole for the passage of fuel towards the injection nozzle; a closing spring which tends to hold the needle in the closing position; and a tubular supporting body having a central channel, which houses the fixed magnetic armature and the movable plunger; wherein the plunger includes a hydraulic type braking device, which is coupled to the feeding hole and hydraulically dissipates more kinetic energy when the needle moves towards the opening position of the injection valve than when the needle moves towards the closing position of the injection valve so as to slow down the opening stroke of the needle, when the needle moves towards the opening position of the injection valve.