Fluid injector, assembly and exhaust line comprising such an injector

An injector of fluid in an exhaust pipe, the fluid being an aqueous urea solution, the injector comprising:

• a single fluid inlet;
• a fluid outlet;
• an injection port to inject the fluid into the exhaust pipe;
• an injection passage, fluidly connecting the single fluid inlet to the injection port;
• a shut-off device comprising a shutter, movable between an open position authorizing circulation of fluid through the injection port and a closed position prohibiting the circulation of fluid through the injection port, and an actuator, configured to selectively move the shutter between the open and closed positions the actuator having a magnetic coil is arranged around an intermediate section of the injection passage extending along a central axis;
• an outer shell, the shut-off device and the intermediate section of the injection passage being housed inside the outer shell;
• a cooling passage, having an upstream portion fluidly branched to the injection passage and a downstream portion fluidly connected to the fluid outlet, the cooling passage being configured so that fluid flow along the cooling passage cools the actuator of the shut-off device the cooling passage comprising a cooling portion arranged around the magnetic coil such that the magnetic coil is cooled by circulation of fluid;
• and
• a fluid pressure regulator interposed in the cooling passage.