Fuel discharge nozzle

A nozzle body is formed with a fuel discharge chamber. A discharge valve opens into the chamber at one end and discharge orifices open from the chamber at the other end at various angles. The axial distances between the orifices and the valve are selected in accordance with the angles in such a manner that the fuel flow paths from the valves to the respective orifices have the same curvature and equal amounts of fuel are discharged through the orifices.

BACKGROUND OF THE INVENTION 
The present invention relates to an improved fuel discharge nozzle which is 
ideally suited for use as a fuel injection nozzle in an automotive 
vehicle. 
The type of fuel discharge nozzle to which the present invention 
constitutes a substantial improvement generally comprises a nozzle body. A 
plurality of fuel discharge orifices open from the tip of the nozzle body 
at different angles to provide a dispersed fuel spray. In all nozzles of 
this type available heretofore, however, the fuel discharge rates through 
the various orifices are unequal in dependence on the angles of the 
orifices. Specifically, the greater the angle the lower the discharge 
rate. Attempts to compensate for this phenomenon by varying the diameters 
of the orifices have only compounded the problem. The effects of such 
uneven spray characteristics are extremely detrimental where the nozzle is 
provided to inject fuel into an internal combustion engine, with the 
irregularity increasing as the fuel discharge rate decreases. 
It is therefore an object of the present invention to provide a fuel 
discharge nozzle having a plurality of fuel discharge orifices opening 
from a nozzle body at different angles in which equal amounts of fuel are 
discharged through all of the orifices. 
It is another object of the present invention to provide a fuel discharge 
nozzle comprising a nozzle body defining therein a fuel discharge chamber, 
a discharge valve opening into the chamber and a plurality of fuel 
discharge orifices opening from the chamber at different angles, the fuel 
flow paths from the valve to the respective orifices having the same 
curvature. 
It is another object of the present invention to provide a fuel discharge 
nozzle comprising a nozzle body difining therein a fuel discharge chamber, 
a discharge valve opening into the chamber and a plurality of fuel 
discharge orifices opening from the chamber at different angles, axial 
distances from the valve to the orifices increasing as the angles 
increase. 
It is another object of the present invention to provide a fuel discharge 
nozzle comprising a nozzle body defining therein a fuel discharge chamber, 
a discharge valve opening into the chamber and a plurality of fuel 
discharge orifices opening from the chamber and having axes which 
intersect an axis of the chamber at different angles, points of 
intersection of the axes of the orifices with the axis of the chamber 
being spaced from the valve by distances which increase with the angles. 
It is another object of the present invention to provide a generally 
improved fuel discharge nozzle. 
Other objects, together with the foregoing, are attained in the embodiment 
described in the following description and illustrated in the accompanying 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
While the fuel discharge nozzle of the invention is susceptible of numerous 
physical embodiments, depending upon the environment and requirements of 
use, substantial numbers of the herein shown and described embodiment have 
been made, tested and used, and all have performed in an eminently 
satisfactory manner. 
Referring now to FIG. 1 of the drawing, a prior art fuel discharge nozzle 
is generally designated as 11 and comprises a nozzle body 12 which defines 
therein a fuel discharge chamber 13. The nozzle body 12 has an axis 14 
which is also considered as the axis of the discharge chamber 13. A fuel 
discharge control valve 15 comprises a needle valve element 16 which is 
engagable with a needle valve seat 17 to control fuel flow into the 
chamber 13 from a fuel source (not shown). First and second fuel discharge 
orifices 18 and 19 respectively open from the chamber 13 into, for 
example, a cylinder of an internal combustion engine (not shown). Although 
more than two orifices may open from the chamber 13, only two are shown 
for simplicity of illustration and serve to explain the principle of the 
present invention. In addition, the other parts of the discharge nozzle 
11, such as a fuel passageway leading to the valve 15, are not the subject 
matter of the invention and are not shown. 
The orifices 18 and 19 open from the chamber 13 along axes 21 and 22 
respectively which intersect the axis 14 of the chamber 13 at a common 
point 23. In order to provide a dispersed spray from the nozzle 11, an 
angle .theta.2 between the axis 22 of the orifice 19 and the axis 14 is 
made greater than an angle .theta.1 between the axis 21 of the orifice 18 
and the axis 14. By simple geometry, it is clear that an axial distance L2 
between the orifice 19 and the valve seat 17 must be less than an axial 
distance L1 between the orifice 18 and the valve seat 17. As a 
consequence, a fuel flow path or streamline 24 leading from the valve 15 
to the orifice 19 is move curved than a fuel flow path or streamline 26 
leading from the valve 15 to the orifice 18. The greater curvature of the 
streamline 24 means that the flow resistance along the streamline 24 is 
also greater, and as a natural consequence less fuel is discharged through 
the orifice 19 than through the orifice 18. 
A fuel discharge nozzle 31 embodying the present invention is designed to 
overcome the drawback of the nozzle 11 and provide equal fuel discharge 
through all discharge orifices regardless of the discharge angles. The 
nozzle 31 comprises a nozzle body 32 which defines therein a fuel 
discharge chamber 33. As with the nozzle 11, the nozzle 31 has an axis 34 
which is also considered as the axis of the discharge chamber 33. A fuel 
discharge control valve 35 comprises a needle valve element 36 which is 
engagable with a needle valve seat 37 to control fuel flow from a fuel 
source (not shown) into the chamber 33. First and second fuel discharge 
orifices 38 and 39 respectively open from the chamber 33 along axes 41 and 
42 which intersect the axis 34 of the chamber 33 at different points 43 
and 44 respectively. An angle .theta.4 between the axis 42 of the orifice 
39 and the axis 34 of the chamber 33 is greater than an angle .theta.3 
between the axis 41 of the orifice 38 and the axis 34. In accordance with 
the principle of the invention, a distance L4 between the valve seat 37 
and the orifice 39 is greater than a distance L3 between the valve seat 37 
and the orifice 38. Fuel flow paths from the valve 35 to the orifices 38 
and 39 are designated as 46 and 47 respectively. 
The prior art nozzle 11 is designed in such a manner that the axes of all 
of the orifices intersect at the common point 23, thus establishing the 
geometical criterion that the axial distances from the valve 15 to the 
orifices decrease as the angles between the orifices and the axis 14 of 
the chamber 13 increase. As discussed above, this is the direct cause of 
unequal fuel discharge through the orifices. 
This problem is overcome in the nozzle 31, in which the axial distances 
between the orifices and the valve 35 increase as the angle increase to 
make the streamlines from the valve 35 to the respective orifices equal in 
curvature and thereby provide equal fuel discharge through all of the 
orifices. As specifically illustrated in FIG. 2, the orifice 39 is 
oriented at a greater angle to the axis 34 than the orifice 38, .theta.4 
being greater than .theta.3, and the distance L4 between the orifice 39 
and the valve seat 37 is greater than distance L3 between the orifice 38 
and the valve seat 37. The distances L4 and L3 are determined 
mathematically or empirically as functions of the angles .theta.3 and 
.theta.4 in such a manner that the streamlines 46 and 47 have the same 
curvature. It is a geometrical consequence that the point 44 of 
intersection between the axis 42 of the orifice 39 and the axis 34 is 
spaced farther from the valve 35 than the point 43 of intersection of the 
axis 41 of the orifice 38 and the axis 34. Although only two orifices are 
shown and described, the principle of the invention directly applies to a 
nozzle having more than two orifices. 
In summary, it will be seen that the problem of uneven fuel discharge 
through orifices oriented at different angles is overcome by axially 
spacing the orifices in such a manner that the fuel flow streamlines 
leading thereto have equal curvature. Modifications within the scope of 
the invention will be possible for those skilled in the art after 
receiving the teachings of the present disclosure.