Patent ID: 9551290
Date: 2017-01-24
CPC Classifications: F02D,F02M

Claim:
1. A fluid injector for a combustion engine burning a given fluid as fuel, the fluid injector comprising: a central longitudinal axis, an injection valve housing with an injection valve cavity, a valve needle axially movable within the injection valve cavity, an electromagnetic actuator unit operable to actuate the valve needle, the electromagnetic actuator unit comprising a pole piece fixedly coupled to the injection valve housing and an armature axially movable within the injection valve cavity and operable to displace the valve needle, wherein the pole piece has a first contact surface and the armature has a second contact surface opposite the first contact surface of the pole piece, wherein one of the first and second contact surfaces is fluid-philic with a contact angle of less than 90° with the given fluid, and wherein the other of the first and second contact surfaces is fluid-phobic with a contact angle of more than 90° with the given fluid and comprises bumps having lateral dimensions between 1 μm and 30 μm.