| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently reduce the pressure pulsation of a discharge pressure by providing a solenoid valve opening a return passage in pumping and a throttle means interposed in the return passage in a device returning a part of the fuel in a pump chamber to a low-pressure passage via the return passage by the reciprocating movement of a plunger. SOLUTION: In operating a fuel injector 1, fuel pressurized by a pump chamber 35 by the raising of a plunger 21 is fed to a common rail 11 through a discharge valve 16 and injected from each injector 13. During raising of the plunger 21, a solenoid valve opens a return passage 20, a part of the high- pressure fuel of the pump chamber 35 is returned to a low-pressure passage 45 via the return passage and a pressure receiving chamber of an accumulator 19. Then, high-pressure fuel pressurized in the pump chamber 35 rapidly flows in the return passage 20 to rapidly reduce the pressure of the pump chamber 35, however, an orifice 22 formed in the return passage 20 suppress the rapid inflow from the pump chamber 35 so as to sufficiently reduce the pressure pulsation of the discharge pressure. |
