Fuel injection apparatus for internal combustion engines

A fuel injection apparatus for internal combustion engines, comprising:

• a fuel injection pump which has a plunger caused to carry out a least reciprocal movement in a predetermined pattern in a bore formed in a plunger barrel to pressurize fuel in the plunger barrel and at least one control sleeve fitted on the plunger, and is capable of regulating both the fuel injection quantity and the timing of the beginning of fuel injection by adjustment of the relative positional relationship between the control sleeve and the plunger;
• a first actuator for regulating the position of the control sleeve to regulate the fuel injection rate;
• a second actuator for regulating the position of the plunger to regulate the fuel injection quantity;
• a first means responsive to at least one condition signal indicating the operating condition of the internal combustion engine for drivingly controlling said first and second actuators in such a way that the optimum fuel injection rate and fuel injection quantity can be obtained at each instant;
• a detecting means for detecting any trouble occurring in the control system for regulating the position of the control sleeve;
• and
• a second means for limiting the control operation by said first means so that an excessive rise in the inner pressure of the cylinders in the internal combustion engine is prevented when the occurrence of trouble is detected by the detecting means,
• wherein said first means has a first control system responsive to at least the condition signal for feed-back controlling the position of the control sleeve so as to obtain the optimum fuel injection rate, and a second control system responsive to at least the condition signal for feed-back controlling the position of the plunger so as to obtain the optimum fuel injection quantity, and
• wherein the first control system has a first calculating means responsive to at least the condition signal for calculating and outputting a first target position signal indicating the optimum position of the control sleeve, a first sensor for producing a first actual position signal indicating the actual position of the control sleeve, means responsive to the first target position signal and the first actual position signal for producing a first error signal relating to a first difference between the target position and the actual position of the control sleeve, and means responsive to the first error signal for producing a first signal for driving the first actuator so as to reduce the first difference to zero.