Diesel engine fuel injection system with a rate-of-injection control arrangement

A fuel injection system for use in a diesel engine, comprising:

• (a) a fuel injection pump of the rotary-distributor type for cyclically delivering a controlled quantity of high pressure fuel, said pump having a pump cylinder and a pump plunger movably received therein to define a pumping chamber, said pump plunger being driven for reciprocating movement and for rotational movement in a synchronized relationship with the operation of the engine, said pump plunger having a central port in communication with said pumping chamber;
• (b) a fuel injection nozzle operatively connected with said injection pump for receiving the high pressure fuel therefrom and for injecting it into an engine cylinder;
• (c) means for controlling the rate of injection of the system in response to varying operating conditions of the engine, said means having a variable volume chamber and an electronically controlled piezoelectric actuator operable to vary the volume of said variable volume chamber in a controlled timed relationship with the movement of the pump plunger;
• and
• (d) means for providing fluid communication between said pumping chamber and said variable volume chamber in such a manner that, during each delivery stroke of said pump plunger, said pumping chamber is communicated for control of the rate of injection with said variable volume chamber only for a predetermined initial stage of pumping stroke of said pump plunger.