Fuel injection valve

Claim 1

A fuel injection valve comprising: i) a solenoid assembly 1 including a yoke 1a having a cup-shaped portion, an axial bore 12 and a cylindrical portion 101, a core 1d having a fuel conduit 11, and a coil 1b enclosing said core 1d; ii) a nozzle body 4 fitted and fixed in the axial bore 12 of said yoke 1a, said nozzle body being cylindrical and having an injection hole 40 at its leading end and a seat face 41 at the back of said injection hole 40; and iii) a tubular control valve 5 fitted in said nozzle body 4, said tubular control valve 5 having a ball 6 fixed at its leading end and enabled to come into output contact with said seat face 41, said tubular control valve 5 having an armature 7 fitted in and affixed to the outer circumference of its rear portion, said armature 7 being lifted by energizing said coil 1b, iv) wherein the ball 6 at the leading end of said tubular control valve 5 has a diameter larger than that of said tubular control valve 5 and equal to the internal diameter of said nozzle body 4, an annular fuel passage 53 being formed between said tubular control valve and said nozzle body and a fuel reserve space 54 being formed between said ball, said seat face 41 and a conduit 42 of said nozzle body and wherein said ball 6 contacts with said conduit 42 of said nozzle body 4 at its largest-diameter portion corresponding to a tangent 60, and wherein said ball 6 is formed in its region containing said tangent 60 with a plurality of grooves 62 which are angled to intersect the axis of said tubular control valve 5.