Patent ID: 8100350
Filing Date: 2012-01-24
Classification: F02M

Abstract:
1. An injector comprising: a valve body that includes an internal space having a generally cylindrical shape and a bottom portion having a nozzle hole, which penetrates through the bottom portion, wherein: a needle valve accommodated in the internal space such that a fuel passage leading to the nozzle hole is formed between an inner circumferential surface of the valve body and an outer circumferential surface of the needle valve, wherein: a thermal expansion member attached on the one end surface of the needle valve, wherein the thermal expansion member is made of a material, which has a larger coefficient of thermal expansion than a material of the needle valve, wherein: the one end surface of the needle valve has a recess defined therein; the recess is recessed in a direction away from the bottom portion of the valve body; the thermal expansion member is accommodated in the recess; the inner surface of the bottom portion includes a seat surface; the needle valve includes a seat part, which is engageable with the seat surface to stop the fuel injection from the nozzle hole; the recess is formed radially inward of the seat part of the needle valve; the thermal expansion member is adapted to radially expand or contract relative to an inner peripheral surface of the recess to decrease or increase a clearance defined radially between the thermal expansion member and the inner peripheral surface of the recess, in response to a change in a temperature of the thermal expansion member; and a radially inner part of the thermal expansion member is securely fixed to a bottom surface of the recess, and a radially outer part of the thermal expansion member is not fixed to the bottom surface of the recess to enable radial displacement of the radially outer part of the thermal expansion member relative to the inner peripheral surface of the recess.