Abstract: When an electronic control unit (ECU) performs post-injection operation, the ECU intermittently implements a post-injection suspending pattern for suspending output of a post-injection command signal after outputting a normal injection command signal. The ECU implements the post-injection suspending pattern in non-overlapping cylinders and certain overlapping cylinders out of the entire overlapping cylinders. Normal injections are performed in the certain overlapping cylinders immediately before the normal injections performed in the non-overlapping cylinders. Thus, heat generation of an injection drive circuit can be reduced. Meanwhile, an injection pressure of the normal injection performed by an injector in each cylinder can be stabilized.

Abstract: When an electronic control unit (ECU) performs post-injection operation, the ECU intermittently implements a post-injection suspending pattern for suspending output of a post-injection command signal after outputting a normal injection command signal. The ECU implements the post-injection suspending pattern in non-overlapping cylinders and certain overlapping cylinders out of the entire overlapping cylinders. Normal injections are performed in the certain overlapping cylinders immediately before the normal injections performed in the non-overlapping cylinders. Thus, heat generation of an injection drive circuit can be reduced. Meanwhile, an injection pressure of the normal injection performed by an injector in each cylinder can be stabilized.

Abstract: The fuel in a compression pump chamber, defined by a compression plunger, is expelled by the compression plunger driven synchronously with the rotation of an engine. An injection plunger is driven by the expelled fuel, thus injecting fuel into an injection pump chamber defined by the injection plunger. A timing passage, closed by the compression plunger, is formed in the compression pump chamber, and a metering passage is formed in the injection pump chamber. The timing and metering passages communicate with a timing valve and a quantity control valve respectively arranged in an electromagnetic valve. The timing and quantity control valves are driven by an energization current such that they operate in cooperation with each other, i.e., when the timing valve is open, the quantity control valve is closed. When the timing valve is closed and the compression plunger returns, the injection plunger also returns and fuel is supplied to the injection pump chamber through the quantity control valve, which is open.