| 摘要 |
PROBLEM TO BE SOLVED: To simplify the structure of a fuel injection device by using a two-way valve in a boost mechanism, to improve the reliability and stability of operation by directly controlling the pressure of a piston actuating chamber, and to reduce the loss of an actuating fluid for actuating the boost mechanism. SOLUTION: The boost mechanism 5 is placed between an accumulator 4 where a fuel from a fuel pump 1 is discharged and an injection mechanism 6. The piston actuating chamber 55 of the booster mechanism 5 is connected to the accumulator 4 through a supply channel 23 and a diaphragm 31. The boost control valve 32 having a two-way valve applies and discharges a pressure to and from the piston actuating chamber 55 to drive a piston with a large diameter and a plunger with a small diameter, thereby boosting the fuel of a plunger chamber 56. A control device 7 achieves desired injection by opening and closing the boost control valve 32 to control the boost action. Further, since the boost control valve 32 allows prompt pressure discharge from the piston actuating chamber 55, the boost control valve 32 is controlled to minimize a valve opening time so as to suppress fuel discharge and reduce energy loss. COPYRIGHT: (C)2004,JPO
|
