PILOT-INJECTION CONTROL DEVICE.

摘要

The present invention relates to a pilot-injection control device wherein fuel in a pump chamber is pilot-injected in such a manner that the volume of a variable volume chamber communicating with the pump chamber through a port being on-off operated at a predetermined position of a plunger during a process of pressurizing the pump chamber by the plunger is varied by extending an actuator or the like of an electrostriction-type actuator during a predetermined opening time of the port for example. In the past, the actuator has been driven when the pressure of the variable volume chamber reaches a predetermined value after the start of plunger lifting. However, with this arrangement, the start of pilot-injection does not catch up with a plunger lift during the high speed rotation, whereby main injection and auxiliary injection are conducted continuously. According to the present invention, the on-off time of the port in the previous injection is detected and the time of driving the actuator for the pilot-injection is determined in response to a signal of the detection, whereby, even during the high speed rotation, the time of pilot-injection is determined earlier, so that the pilot-injection is not delayed.