Fuel injection nozzle

Patent metadata

Field	Value
Publication number	US-9732716-B2
Application number	US-201615001559-A
Country	US
Kind code	B2
Filing date	Jan 20, 2016
Priority date	Jan 22, 2015
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

In an injection hole of a nozzle, a maximum value of a longitudinal length of an inlet, which is measured in a direction of an inlet longitudinal axis of the inlet, is larger than a maximum value of a longitudinal length of an outlet, which is measured in a direction of an outlet longitudinal axis of the outlet. A rear end edge of an opening edge of the inlet is shaped into an arc. When the maximum value of the inlet is made larger than the maximum value of the outlet, an upstream end of the inlet can be placed at a further upstream side, so that a turn angle of a fuel flow can be reduced to increase the flow coefficient. Furthermore, when the rear end edge is shaped into the arc, the maximum value of the inlet can be increased.

First claim

What is claimed is:

1. A fuel injection nozzle comprising:
a nozzle body that is shaped into a tubular form; and
a needle that is received in an inside of the nozzle body in such a manner that the needle is movable in an axial direction of the nozzle body, wherein the fuel injection nozzle starts or stops injection of fuel by lifting or seating the needle relative to a seat portion, which is formed in an inner peripheral portion of the nozzle body, wherein:
the nozzle body includes an injection hole that opens in both of an inner wall and an outer wall of the nozzle body on a tip end side of the seat portion in the axial direction, wherein the tip end side is a side where a tip end of the nozzle body is placed, while a rear end side is a side where a rear end of the nozzle body is placed;
in a state where the needle is seated against the seat portion, when the needle is moved from the seat portion toward the rear end side in the axial direction, the needle is lifted from the seat portion, and thereby the fuel is guided from the inside of the nozzle body to an outside of the nozzle body through the injection hole;
with respect to an inlet, which is an opening of the injection hole in the inner wall, an inlet transverse axis is defined to extend in a circumferential direction of the nozzle body in parallel with a plane of the inlet, and an inlet longitudinal axis is defined to extend in a direction perpendicular to the inlet transverse axis in parallel with the plane of the inlet;
with respect to an outlet, which is an opening of the injection hole in the outer wall, an outlet transverse axis is defined to extend in the circumferential direction in parallel with a plane of the outlet, and an outlet longitudinal axis is defined to extend in a direction perpendicular to the outlet transverse axis in parallel with the plane of the outlet;
a maximum value of a longitudinal length of the inlet measured in a direction of the inlet longitudinal axis is larger than a maximum value of a longitudinal length of the outlet measured in a direction of the outlet longitudinal axis;
a maximum value of a transverse length of the inlet measured in the direction of the inlet transverse axis is defined between two maximum transverse length forming points of an opening edge of the inlet, and a rear end portion of the opening edge of the inlet, which is located on the rear end side of the two maximum transverse length forming points, is shaped into an arc;
a remaining portion of the opening edge of the inlet, which is other than the rear end portion and is located on the tip end side of the two maximum transverse length forming points, includes two straight lateral edges, which extend linearly and are respectively placed at one circumferential side and another circumferential side of the opening edge of the inlet; and
the two straight lateral edges are tapered toward the tip end side, and thereby the transverse length, which is measured between the two straight lateral edges in the direction of the inlet transverse axis, is progressively decreased from the two maximum transverse length forming points toward a tip end of the opening edge of the inlet.

2. The fuel injection nozzle according to claim 1 , wherein in the opening edge of the inlet, the two maximum transverse length forming points are located on the rear end side of a point, at which ½ of the maximum value of the longitudinal length of the inlet is measured along the inlet longitudinal axis.

3. The fuel injection nozzle according to claim 1 , wherein a maximum value of a transverse length of the outlet measured in a direction of the outlet transverse axis is larger than the maximum value of the transverse length of the inlet measured in the direction of the inlet transverse axis.

4. The fuel injection nozzle according to claim 1 , wherein the rear end portion is an arcuate rear end edge that connects between the two maximum transverse length forming points and is arcuate along an entire extent of the arcuate rear end edge between the two maximum transverse length forming points.

5. The fuel injection nozzle according to claim 1 , wherein the injection hole is one of a plurality of injection holes, which are arranged one after another in the circumferential direction at the nozzle body.

Assignees

• Denso Corp

Inventors

• Serizawa Kazufumi
• Sano Shinya
• Utsunomiya Atsushi

Classifications

• F02M61/184 Primary

  Discharge orifices having non circular sections · CPC title

• F02M61/10 Primary

  Other injectors with elongated valve bodies, i.e. of needle-valve type · CPC title

• F02M61/1833

  Discharge orifices having changing cross sections, e.g. being divergent · CPC title

• F02M61/1846

  Dimensional characteristics of discharge orifices · CPC title

• F02M61/1806 Primary

  characterised by the arrangement of discharge orifices, e.g. orientation or size · CPC title