Hydraulically intensified high pressure fuel system for common rail application

A common rail intensifier, fuel injection system for a multi-cylinder internal combustion engine with multiple cylinders, comprising:

• a plurality of fuel injectors respectively associated with the multiple cylinders;
• a common rail for supply of fuel at an intensified pressure to said plurality of fuel injectors;
• a fuel supply containing fuel at a low pressure relative to the intensified pressure within the common rail;
• at least two fuel pressure intensifying circuits for alternately supplying fuel at the intensified pressure to said common rail;
• an operating fluid source;
• a first fuel pressure intensifier in one of said pressure intensifying circuits and comprising an operating chamber of a first diameter for receiving and discharging the operating fluid, a fuel chamber of a second diameter, smaller than said first diameter, for receiving fuel at the low pressure from said fuel supply and discharging fuel at the intensified pressure to said common rail;
• a first control valve for, in a first position, connecting said operating fluid source with said operating chamber of said fuel pressure intensifier and, in a second position, connecting said operating chamber of said fuel pressure intensifier with a drain;
• and
• control means for switching said control valve between the first and second positions and for switching supply of fuel at the intensified pressure to said common rail between said fuel pressure intensifying circuits.