Abstract: A fuel injection valve is attached to an engine and to have an annular seal material attached thereon. The seal material is attached to a first reduced diameter part. In a use state where a body is inserted in an attachment hole formed at a predetermined position of the engine and a gas pressure that is equal to or higher than a predetermined pressure is applied to the seal material from its nozzle hole-side, the seal material is pressed against a first tapered part by the gas pressure to be compressively deformed, and a clearance between an inner peripheral surface of the attachment hole and an outer peripheral surface of the body is sealed with a compressively-deformed part of the seal material. A taper angle of the first tapered part is set in a range from 10 degrees to 20 degrees.

Abstract: A fuel injector includes a body having a fuel injection port, and a seal ring on the body. The body has a diameter-shrink portion of which an outer diameter is shrunk. The seal ring is engaged with the diameter-shrink portion. The diameter-shrink portion has a radially concaved annular groove with which a tip end portion of the seal ring is engaged. It is restricted that the seal ring is rubbed against an inner surface of the assembling hole and the seal ring is damaged.

Abstract: A fuel injection valve is attached to an engine and to have an annular seal material attached thereon. The seal material is attached to a first reduced diameter part. In a use state where a body is inserted in an attachment hole formed at a predetermined position of the engine and a gas pressure that is equal to or higher than a predetermined pressure is applied to the seal material from its nozzle hole-side, the seal material is pressed against a first tapered part by the gas pressure to be compressively deformed, and a clearance between an inner peripheral surface of the attachment hole and an outer peripheral surface of the body is sealed with a compressively-deformed part of the seal material. A taper angle of the first tapered part is set in a range from 10 degrees to 20 degrees.

Abstract: A fuel injector includes (i) a body including a distal end portion forming an injection port, a diameter reduction portion, and a diameter expansion portion, and (ii) a seal member attached to at least the diameter reduction portion of both the diameter reduction portion and the diameter expansion portion. When the body is inserted into an attachment hole communicating with a combustion chamber of an internal combustion engine, the seal member seals between an inner peripheral surface of the attachment hole and an outer peripheral surface of the body. The seal member includes a first taper portion chamfered and provided at an outer periphery of a distal end portion of the seal member in a case where the distal end portion of the seal member is placed at a position relatively close to the injection port.

Abstract: A fuel injector includes a body having a fuel injection port, and a seal ring on the body. The body has a diameter-shrink portion of which an outer diameter is shrunk. The seal ring is engaged with the diameter-shrink portion. The diameter-shrink portion has a radially concaved annular groove with which a tip end portion of the seal ring is engaged. It is restricted that the seal ring is rubbed against an inner surface of the assembling hole and the seal ring is damaged.