Exhaust gas recirculation control system for an internal combustion engine

In a diesel engine, comprising an exhaust system, an inlet system, and an exhaust gas recirculation system, a device which is the combination of:

• a fuel injection pump which comprises a movable fuel amount determining element, the position of which regulates the amount of fuel provided for injection by the fuel injection pump;
• a conversion device, comprising:
• a fixed orifice, to the upstream side of which is supplied a substantially constant fluid pressure;
• a fluid passage downstream of the fixed orifice;
• a pressure takeoff passage branching from the fluid passage;
• and
• a variable orifice downstream of the fluid passage whose effective opening area is varied according to the movement of the fuel amount determining element;
• fluid flowing from the upstream side of the fixed orifice through it, through the fluid passage, and through the variable orifice, in that order, the pressure of fluid at the point where the pressure takeoff passage branches from the fluid passage varying according to the position of the fuel amount determining element;
• an exhaust gas recirculation control valve, which controls the amount of exhaust gas recirculated from
• the exhaust system to the inlet system through the exhaust gas recirculation system;
• and,
• an actuator, which is energized by the fluid pressure supplied through the pressure takeoff passage, and operates the exhaust gas recirculation control valve.