Electronic fuel injection control system for fuel injection valves

An electronic fuel injection control system adapted for combination with at least one fuel injection valve having an injection nozzle, said injection nozzle having a nozzle needle arranged to be lifted by fuel pressure, said fuel injection control system comprising:

• pressurized fuel supply means;
• passage means for leading pressurized fuel from said fuel supply means to said injection nozzle;
• injection timing regulating means for selectively opening and closing said passage means;
• an engine load sensor for detecting a load on said engine;
• an engine speed sensor for detecting the speed of said engine;
• a valve opening pressure sensor for detecting the valve opening pressure of said injection nozzle;
• valve opening pressure regulating means for regulating the valve opening pressure of said injection nozzle;
• detecting means for detecting a condition of an engine associated with said fuel injection valve to produce electrical signals indicative of the condition of said engine;
• electronic control means responsive to said electrical signals to control said injection timing regulating means and said valve opening pressure varying means, said electronic control means including means for arithmetically calculating first and second control signals in a predetermined manner in response to said electrical signals and for supplying said first control signal to said injection timing regulating means to cause said injection timing regulating means to obtain a desired injection timing for the condition of said engine, and for supplying said second control signal to said valve opening pressure regulating means to cause said valve opening pressure regulating means to obtain a desired injection rate for the condition of said engine;
• memory means for storing target values of valve opening pressure corresponding to various conditions of said engine, said memory means being arranged to be supplied with outputs from said engine load sensor and outputs from said engine speed sensor;
• and
• a valve opening pressure controller arranged to be supplied with an output from said valve opening pressure sensor and with a target valve output from said memory means to control said valve opening pressure regulating means;
• said memory means and said valve opening pressure controller forming part of said electronic control means;
• said memory means being responsive to outputs from said engine load sensor and to outputs from said engine speed sensor to selectively supply a desired target value of valve opening pressure to said valve opening pressure controller;
• said valve opening pressure controller including means responsive to an output from said valve opening pressure sensor to correct said desired target value supplied from said memory means and to produce a resulting corrected target value.

An electronic fuel injection control system adapted for combination with at least one fuel injection valve having an injection nozzle, said injection nozzle having a nozzle needle arranged to be lifted by fuel pressure, said fuel injection control system comprising:

• pressurized fuel supply means;
• passage means for leading pressurized fuel from said pressurized fuel supply means to said injection nozzle;
• injection timing regulating means for selectively opening and closing said passage means;
• valve opening pressure regulating means for regulating the valve opening pressure of said injection nozzle;
• injection pressure regulating means for regulating fuel pressure supplied to said injection nozzle;
• detecting means for detecting a condition of an engine associated with said fuel injection valve to produce electrical signals indicative of said engine condition;
• and
• electronic control means responsive to said electrical signals to control said injection timing regulating means, said valve opening pressure regulating means and said injection pressure regulating means, said electronic control means including means for arithmetically calculating first, second or third control signals in a predetermined manner in response to said electrical signals and for supplying said first control signal to said injection timing regulating means to cause said injection timing regulating means to obtain a desired injection timing for said engine condition, and for supplying said second and third control signals to said valve opening pressure regulating means and to said injection pressure regulating means to cause same to obtain a desired injection rate for the condition of said engine.