| 摘要 |
PURPOSE:To reduce force disturbing the action opening and closing a needle valve and improve a response characteristic of the needle valve at its switching time, by forming a movable core, with which the needle valve opening and closing a fuel injection hole is integrally connected, using a plate-shaped material consisting of magnetic material. CONSTITUTION:If voltage is applied to an electromagnetic coil 19 through a terminal line 22, a fixed iron core 13 is magnetized attracting a movable core 14 against pressing force of a spring 15 to a needle valve 31. As a result, the needle valve 31, integrally connected with the movable core 14, is detached from a valve seat 33 and lifted, opening a fuel injection hole 34. Here the movable core 14, being formed by winding a thin plate-shaped material 14a in a volute state, enables the value of an eddy current, generated in accordance with magnetic flux appearing and disappearing at switching time, to be decreased. Accordingly, a response characteristic of the valve at its switching time can be improved. While an amorphous material having an excellent response characteristic can be used as a magnetic material because the movable core 14 is formed by the thin plate-shaped material 14a. |
