IMPROVEMENT TO LIQUID FLUID INJECTION PUMPS

An injection pump having a pump body provided with an inlet conduit supplying an inlet chamber, and a compression chamber downstream from the inlet chamber under which a piston reciprocates to distribute liquid fluid from the compression chamber to an outlet pipe in communication with a common rail circuitry. The injection pump has a valve provided with a resilient cup, located between the inlet chamber and the compression chamber and actuated by an electromagnetic actuator through a pushing rod wherein operation of the valve allows the piston to suck liquid fluid from the inlet chamber into the compression chamber and feed the common rail circuitry or to push back liquid fluid in said inlet chamber and said inlet conduit, in which the pump comprises a filter provided around the pushing rod and located between the valve and the electromagnetic actuator in the inlet chamber.