PILOT INJECTION CONTROL METHOD

摘要

PURPOSE:To eliminate the time lag of injection so as to make a pilot injection control easy by effecting the control of increasing the volume of a variable volume chamber by the lift of a pump plunger coming in touch with the variable volume chamber provided to the high pressure chamber of a fuel pump. CONSTITUTION:A face cam 13 coming in contact with a roller 14 supported by a roller ring 15 is arranged at the outer end of a plunger 11 driven by a drive shaft 18, and the plunger 11 is installed rotatably while it is reciprocated as required to the direction of the shaft. And the lift of the plunger 11 can be controlled by rotating the cam 13 to the circumferential direction by means of a timer piston 19. A variable volume pump chamber 20 is formed in a space between the end surface of the plunger 11 and a piston 23 is a housing 12b for making the volume of the pump chamber 20 variable by forwarding and retracting the piston 23 with a laminated piezo-electric element 25 extended and contracted through the energizing control of electricity. The laminated element 25 is placed under the energizing control of electricity in accordance with the output from a pick-up sensor 16 for enabling the generation of a predetermined pilot injection pattern.