摘要 |
A servo valve is arranged within a timer piston for displacement in response to fuel pressure variable as a function of the engine rpm. When there occurs a change in the fuel pressure, the servo valve is automatically displaced relative to the timer piston to open a passageway for supplying the above fuel pressure to a hydraulic oil chamber defined at one end of the timer piston to cause displacement of the timer piston for control of injection timing. When there is no change in the fuel pressure, the servo valve is positioned to close the passageway to hold the timer piston stationary. Further, means may be provided for adjusting the setting load of a servo spring urging the valve body of the servo valve against the above fuel pressure.
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