Patent ID: 7284712
Filing Date: 2007-10-23
Classification: F02M

Abstract:
1. An injector comprising: an elongated base body; an injection hole, which penetrates through a wall of the base body to inject fuel; a nozzle chamber, which is directly communicated with the injection hole on an upstream side of the injection hole in the base body and is supplied with pressurized fuel; a nozzle needle, which is located in the nozzle chamber and is driven to enable and disable injection of the fuel through the injection hole; a nozzle needle back pressure chamber, which is formed adjacent to a base end of the nozzle needle in the base body and is supplied with pressurized fuel to exert a back pressure of the nozzle needle for urging the nozzle needle toward the injection hole; a release passage, which is formed in the base body to release the pressure of the nozzle needle back pressure chamber to an external low pressure source; a control valve chamber, which is located in an intermediate part of the release passage in the base body; a first control valve, which is located in the control valve chamber and is driven to connect and disconnect between the nozzle needle back pressure chamber and the low pressure source; and a valve drive means for driving the first control valve, wherein the valve drive means is a hydraulic valve drive means that includes: