| 摘要 |
PURPOSE:To provide a fuel injection pump for an internal combustion engine in which the speed of a delivery valve is decreased at the end of a descending motion thereof to thereby reduce production of noises and is increased at the beginning of a descending motion of thereof to thereby ensure its sucking-back effect by constituting the pump such that a cam for control of the valve has an appropriate profile which provides such motion of the valve. CONSTITUTION:When a cam 10 is rotated in a counterclockwise direction to raise a plunger 2, a recessed section 1a of the plunger 2 passes by an inlet/outlet hole 5 so that pressure in a chamber 6 is raised and soon exceeds the force of a spring 3 whereupon a delivery valve 4 is raised to thereby effect discharge of fuel. When the plunger 2 begins its descending motion upon a continued rotation of the cam 10, the plunger 2 and the delivery valve 4 are first permitted to rapidly descend due to a steep declination b of the cam 10 thereby to effect an assured sacking- back operation. At the end of a descending motion, the descending speed of the plunger 2 is moderated due to a moderate declination c of the cam 10. After the recessed section 1a of the plunger 2 is displaced below the inlet/outlet hole 5, fuel is sucked in. Feed of fuel is thus effected repetitively in such a sequence of operations as described above. |
