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(11) | EP 0 971 119 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Common-rail fuel-injection system |
| (57) A common-rail fuel-injection system is disclosed, in which varying the effective
stroke of an actuator-operated valve (42) results in adjusting an amount of fuel leaking
out of a pressure-control chamber (40), thereby controlling the fuel injection in
compliance with the engine operating conditions. When the lift of the valve (42) is
small and therefore the opening area of the valve (42) is less than the cross-sectioned
area of a fuel leakage path (41), the leakage of high-pressure fuel out of the pressure
is defined by the lift of the valve (42). According to the pressure fall in the pressure-control
chamber (40), the lift of a needle valve (24) is regulated to thereby control the
fuel-injection rating, namely, the quantity of fuel injected and the rate of change
of the fuel-injection rating. An exciting signal applied to the actuator (65) to operate
the its associated valve is determined in accordance with a desired fuel-injection
rating or the like, which is found in compliance with the engine operating conditions. |