Fuel injection valve.

摘要

This invention relates to an electromagnetic fuel injection valve having a body 1 of magnetic material, a core 4 and a hollow plunger 6, 35 disposed in the body and formed with a fuel passage 30, 31 communicating with a valve chamber 18. A ball valve 7 is secured to the end of the plunger and nestingly received in a seat member 13, 33, and a solenoid coil 3 is provided for opening the ball valve 7 upon energization thereof to pass fuel through the valve.
A guide pipe 65 is provided on the outer peripheral surface of said core 4 and extends axially beyond a proximal end thereof to said valve chamber 18, and a stop means 16, 36 is provided on said plunger 6, 36 at the valve chamber end thereof for engagement with the axially extended portion of said guide pipe 5 for limiting the stroke of said plunger 6. A divergent part-conical or spherical surface is formed at the end of the guide pipe 5 and a part-spherical surface 17 is provided on the side of the stop means 16 of the plunger 6 remote from said ball 7 for co-operation with said guide pipe end surface 17 so as to provide an automatic centering operation at the stroke end of the plunger 6, thereby preventing irregular wear of the ball valve and the seat surface to maintain the performance over an extended period of use.