Accumulator fuel injection system

An accumulator fuel injection system, comprising:

• a first accumulator for storing high-pressure fuel;
• a fuel injection nozzle connected to said first accumulator via a fuel passage to inject fuel into a combustion chamber of an engine;
• a switching valve for connecting and disconnecting the high-pressure fuel stored in said first accumulator to and from said fuel passage;
• a second accumulator connected to a part downstream said switching valve in said fuel passage via a branch passage, said second accumulator storing fuel of lower pressure than the high-pressure fuel in said first accumulator;
• a pressure control valve provided in at least one of the part downstream of said switching valve in said fuel passage and said second accumulator, said pressure control valve regulating a fuel pressure in said second accumulator and said fuel passage;
• an opening and closing valve for controlling injection of fuel from a fuel injection nozzle;
• a main injection control device for controlling said switching valve and said opening and closing valve according to an operating state of the engine such that main fuel is injected from said fuel injection nozzle for a predetermined period of time;
• and
• a post injection control device for injecting additional fuel from said fuel injection nozzle after said main injection control device injects the main fuel, in a case where it is necessary to raise an exhaust temperature of the engine,
• wherein said post injection control device provides control such that additional fuel is injected from said fuel injection nozzle when the fuel pressure in said fuel passage or said second accumulator has been reduced to a low pressure approximate to a pressure of the low-pressure fuel stored in said second accumulator via said pressure control valve.