Patent ID: 8402945

Claim:
An injector adapted to be disposed in an internal combustion engine for injecting fuel into the engine, the injector comprising: a nozzle hole through which fuel is injected; a metal body that includes a high pressure passage inside the body, wherein high pressure fuel flows into the nozzle hole through the high pressure passage; and a fuel pressure sensor that is attached to the body and configured to detect pressure of high pressure fuel, wherein: the fuel pressure sensor includes: a metal flexure element that is resiliently deformed to produce a flexure upon application of the pressure of high pressure fuel to the flexure element; and a sensor element that is configured to convert the flexure produced in the flexure element into an electrical signal and to output the signal as a pressure detection value; and the body further includes: a sensor high pressure passage that communicates with the flexure element, wherein carburizing treatment is performed on at least a part of the body that defines the sensor high pressure passage; and a body side sealing surface on which the flexure element is pressed and closely-attached so that a clearance between the body and the flexure element is metal-to-metal sealed on the body side sealing surface, wherein the carburizing treatment is not performed on the body side sealing surface of the body.