Nozzle plate for fuel injection unit

A nozzle plate for a fuel injection unit, comprising:

• a plurality of nozzle orifices placed to face a fuel injection nozzle of a fuel injection unit to allow passage of fuel injected from the fuel injection nozzle, wherein
• the nozzle orifice is connected to the fuel injection nozzle through a swirl chamber, a first fuel guide groove and a second fuel guide groove opened to the swirl chamber,
• the swirl chamber is shaped by bisecting an oval recess into a first semi-oval recess and a second semi-oval recess with respect to a major axis of the oval recess and deviating the first semi-oval recess and the second semi-oval recess from each other along the major axis as a surface side facing the fuel injection nozzle is seen in a plan view, the first fuel guide groove opening to a deviated part of the first semi-oval recess and the second semi-oval recess positioned in one end side of the major axis, the second fuel guide groove opening to a deviated part of the first semi-oval recess and the second semi-oval recess positioned in the other end side of the major axis,
• the first and second fuel guide grooves are formed such that the identical amount of fuel flows from the fuel injection nozzle to the swirl chamber,
• a swirl chamber side connecting portion of the first fuel guide groove and a swirl chamber side connecting portion of the second fuel guide groove are formed to be double-symmetrical with respect to a center of the swirl chamber, and
• an identical amount of the fuel flowing from the first and second fuel guide grooves to the swirl chamber is guided to the nozzle orifice while revolving inside the swirl chamber in an identical direction.

A nozzle plate of a fuel injection unit, comprising:

• a plurality of nozzle orifices placed to face a fuel injection nozzle of a fuel injection unit to allow passage of fuel injected from the fuel injection nozzle, wherein
• the nozzle orifice is connected to the fuel injection nozzle through a swirl chamber, a first fuel guide groove and a second fuel guide groove opened to the swirl chamber,
• the swirl chamber is an oval recess formed in a surface side facing the fuel injection nozzle and provided with the nozzle orifice in a center of the swirl chamber, the first fuel guide groove opening to one end side of a minor axis of the oval recess, the second fuel guide groove opening to the other end side of the minor axis of the oval recess,
• the first and second fuel guide grooves are formed such that the identical amount of fuel flows from the fuel injection nozzle to the swirl chamber,
• a swirl chamber side connecting portion of the first fuel guide groove and a swirl chamber side connecting portion of the second fuel guide groove are formed to be double-symmetrical with respect to a center of the swirl chamber, and
• wherein an identical amount of the fuel flowing from the first and second fuel guide grooves to the swirl chamber is guided to the nozzle orifice while revolving inside the swirl chamber in an identical direction.

A nozzle plate of a fuel injection unit, comprising:

• a plurality of nozzle orifices placed to face a fuel injection nozzle of a fuel injection unit to allow passage of fuel injected from the fuel injection nozzle,
• the nozzle orifice is connected to the fuel injection nozzle through a swirl chamber, a first fuel guide groove and a second fuel guide groove opened to the swirl chamber,
• the swirl chamber is shaped by combining a first oval recess formed in a surface side facing the fuel injection nozzle and a second oval recess having an identical size as that of the first oval recess, the second oval recess having a minor axis arranged in an extension line of a minor axis of the first oval recess, the second oval recess having a center separated from a center of the first oval recess by a predetermined length, the first oval recess and the second oval recess partially overlapping with each other, the first fuel guide groove opening to an end side of the minor axis of the first oval recess not overlapping with the second oval recess in an end side of the minor axis of the first oval recess, the second fuel guide groove opening to an end side of the minor axis of the second oval recess not overlapping with the first oval recess in an end side of the minor axis of the second oval recess, the nozzle orifice being formed in a center of the swirl chamber,
• the first and second fuel guide grooves are formed such that the identical amount of fuel flows from the fuel injection nozzle to the swirl chamber,
• a swirl chamber side connecting portion of the first fuel guide groove and a swirl chamber side connecting portion of the second fuel guide groove are formed to be double-symmetrical with respect to a center of the swirl chamber, and
• wherein an identical amount of the fuel flowing from the first and second fuel guide grooves to the swirl chamber is guided to the nozzle orifice while revolving inside the swirl chamber in an identical direction.