Patent ID: 6240897
Filing Date: 2001-06-05
Classification: F02M

Abstract:
An electromagnetic fuel injection valve with a movable valve seat comprising a valve body, a solenoid, a stator, an armature and valve needle assembly, and a valve seat assembly, adapted to be mounted on a cylinder head of an internal combustion engine for directly injecting fuel into a cylinder, said armature and valve needle assembly being attracted by magnetic force to overcome force of a spring to contact said stator thereby injecting fuel into said cylinder;said valve seat assembly being movably fitted within said valve body, engaged with said valve body in air-tight manner, having a set of four circumferential ridges to keep concentric with said valve seat assembly having a front end made of hardened steel and protruding out of said valve body and enabling said valve needle to move therein to open or close a single-hole or multi-hole nozzle, the rear part made of non-magnetic metallic tube in which are fitted said stator and armature, whereby when said cylinder is at low pressure, said valve seat is subjected to fuel pressure, spring force and elastic force of an elastomer to position a shoulder at an intermediate portion in said valve body, and when said cylinder is at high pressure, said valve seat will be forced to move;said armature and valve needle assembly provided at a front end with a valve needle made of hardened steel and engageable with said valve seat assembly, said valve needle having two sets of four circumferential ridges so as to be concentric with said valve seat assembly for enabling passage of fuel and provided at a rear end with an armature made of soft iron which forms a closed magnetic circuit with said stator and said valve body, said stator receiving a spring for pushing said armature and valve needle assembly to original position thereby supplying fuel through a hole of said stator and a hole of said armature.