Patent ID: 7814890
Filing Date: 2010-10-19
Classification: F02M

Abstract:
1. A fuel injector for injection of fuel at a high pressure in a combustion engine, comprising at least one passage for receiving fuel at a first above-atmospheric pressure from a fuel source; a pressure amplifier connected with the one passage and operable to generate a fuel pressure increase to a second pressure higher than the first pressure; an injection valve from the pressure amplifier and comprising a valve element movable between a closed position preventing fuel injection past the valve element and an open position wherein fuel is injected past the valve element to the engine; a first chamber of the injector, which is divided into a closing chamber and an opening chamber; a piston element located in and dividing the first chamber, the piston element including a first side in contact with the closing chamber, an opposite second side in contact with the opening chamber, and at least one duct running through the piston element between the closing chamber and the opening chamber, the piston element being connected with the valve element to move the valve element as the piston element is moved; a first spring operable to exert a force on the piston element in order to move the valve element towards the closed position; the pressure amplifier being operable to generate, the second fuel pressure in the opening chamber to move the valve element towards the open position for injecting fuel from the injector to the engine; a passage connecting the closing chamber to the fuel source for at least a substantial portion of the time when the valve element is to move towards the closed position, so that the first pressure and the first spring together provide a force to move the valve element towards the closed position; and an outlet to the engine for fuel from the opening chamber which passes the valve element.