Accumulator fuel injection apparatus

摘要

Pressurized fuel of a common rail (3) is introduced into a control chamber (121) of a fuel injector (1). An electromagnetic valve (1a) opens or closes a fuel discharge passage (205) of the control chamber (121) to adjust a hydraulic pressure of the control chamber (121). Through a switching leak passage (2a), bubble-containing fuel directly returns from a valve opening (124) of the electromagnetic valve (1a) to a low-pressure return passage (212, 213) without passing through an armature chamber (132). Through a stationary leak passage (2b), the fuel leaking from every slide portion returns to the return passage (212, 213) via the armature chamber (132). A downstream portion (2b1) of the stationary leak passage (2b) opens to the upper portion (132a) of the armature chamber (132). A damper element (502a) is provided downstream of the electromagnetic valve (1a) in the return passage for canceling an increased fuel pressure.