| 摘要 |
PURPOSE:To shorten the valve-close operation time by forming regularly managed coarse face thereby eliminating the attraction force quickly through reduction of residual flux to be produced in the colliding face between flat movable core and magnetic ring while reducing the adhering force of fuel. CONSTITUTION:When attracting a flat movable core 20 to a magnetic ring 13, the upper face will contact tightly against the coarse face 30 of magnetic ring 13. Upon interruption of exciting current, the coarse face 30 will be a low magnetic layer because the concave face will form a gap against the upper face of said core 20 thus to reduce the magnetic adhering force and to facilitate elimination of residual flux. Furthermore, said gap will reduce the contact-tight area between said core 20 and ring 13 thus to reduce adhering force due to fuel. Consequently, said core 20 is moved quickly in the valve-close direction to seat a ball valve body 23 in a valve seat 26 thus to close the fuel injection hole 27 instantaneously. |
