[0001] The present disclosure described herein, in general, relates to a fuel
injector for injecting fuel in an engine cylinder of an internal combustion engine.
5 The present disclosure also relates to the fuel injector with multiplane injector
orifices arrangement with different Orifice diameters for Homogenous Air/fuel
mixture preparation inside combustion chamber across all load conditions.
BACKGROUND
[0002] The background description includes information that may be useful in
10 understanding the present disclosure.
[0003] Internal combustion engines, specifically diesel engines often employ
a so-called multiple fuel injection processes to transmit pressurized and atomized
fuel through a one or multiple orifices of a fuel injection system into a combustion
chamber or engine cylinder of an engine. However, such existing fuel injection
15 systems particularly share the disadvantages of inadequate homogeneity of the airfuel mixture cloud, cylinder wall and piston wall wetting/quenching, high
combustion sound (knocking) and incomplete combustion and consequently,
emission of higher quantities of effluents.
[0004] The internal combustion engine operates in load and high conditions.
20 Emission of particulate matter, i.e., soot particle is high in low load condition. As
air density and pressure is very low in the combustion chambers at the low load
application which offers little resistance to spray penetration of fuel from the fuel
injectors.
[0005] To overcome the generation of particulate matter, amount of air to be
25 used in the combustion chamber is increased. With increase of air in the
combustion chamber, production of nitrogen oxides (NOx) as emissions increase
which is also strictly regulated.
3
[0006] Further, production of soot particles and NOx can be controlled by
homogeneous mixture of air-fuel which can be obtained by structure of fuel
nozzle and timing of fuel nozzle spray.
[0007] In view of the above, there is requirement for optimization of fuel
5 nozzle structure for improving the emissions, combustion noise, and combustion
efficiency and methods that reduce the above-mentioned drawbacks or
disadvantages.
OBJECTS OF THE DISCLOSURE
[0008] Some of the objects of the present disclosure, which at least one
10 embodiment herein satisfy, are listed hereinbelow.
[0009] It is a general object of the present disclosure to provide a fuel injector
with multiplane injector orifice arrangement for injecting fuel into an engine
cylinder and a method for Homogenous Air/fuel mixture preparation inside
combustion chamber across all load conditions.
15 [0010] Another object of the present subject matter is to provide a fuel
injector with multiplane injector orifice arrangement with different Orifice
diameters and a method to operate the fuel injector that reduces knocking and
harmful emissions of effluents.
[0011] These and other objects and advantages will become more apparent
20 when reference is made to the following description and accompanying drawings.
SUMMARY
[0012] This summary is provided to introduce concepts related to a fuel
injector with multiplane injector orifice arrangement for injecting fuel into an
engine cylinder and a method for operating the fuel injector. The concepts are
25 further described below in the detailed description. This summary is not intended
to identify key features or essential features of the claimed subject matter, nor is it
intended to be used to limit the scope of the claimed subject matter.
4
[0013] The subject matter disclosed herein relates to a fuel injector for
injecting a fuel into an engine cylinder. The fuel injector comprising an injector
casing and an injector needle. Both defining conical shaped end portions to
spray/inject fuel into the combustion chamber. The injector casing defines a
5 conical shaped end portion with a vertex portion and a base portion. The conical
shaped end portion of the injector casing comprises a plurality of first orifices and
a plurality of second orifices on circumference of the conical shaped end portion.
The plurality of second orifices is located in between the plurality of first orifices
and the vertex portion. Further, the injector needle defines a conical shaped nozzle
10 body with a vertex portion and base portion. The conical shape nozzle body
comprises a plurality of first reservoirs and a plurality of second reservoirs located
on circumference of the nozzle body, the plurality of second reservoirs located in
between the plurality of first reservoirs and the vertex portion. A sealing portion
which is provided in between the plurality of first reservoirs and the plurality of
15 second reservoirs on circumference of the conical shaped nozzle body. The
conical shape nozzle body of the injector needle moves inside the conical end
portion of the injector casing to inject fuel. The fuel injector injects the fuel into
the engine cylinder when the plurality of second orifices in-line with the plurality
of second reservoirs and the plurality of first orifices in-line with the plurality of
20 first reservoirs.
[0014] In an aspect, diameter (Da) of the plurality of first orifices is less than
diameter (Db) of the plurality of second orifices.
[0015] In an aspect, volume (Va) of the plurality of first reservoirs is less than
volume (Vb) of the plurality of second reservoirs.
25 [0016] In an aspect, the plurality of first orifices and the plurality of second
orifices are offset to each other.
[0017] In an aspect, number of orifices in the plurality of first orifices and in
the plurality of second orifices on the conical shaped end portion of the injector
casing are equal in number of reservoirs in the plurality of first reservoirs and in
5
the plurality of second reservoirs on the conical shaped nozzle body of the injector
needle, respectively.
[0018] In an aspect, the plurality of first orifices has a spray angle (α) and the
plurality of second orifices has a spray angle (β), the spray angle (α) is greater the
5 spray angle (β) or the spray angle (β) and the spray angle (α) are same.
[0019] In an aspect, each of the plurality of first orifice and the plurality of
second orifice surrounded by inclined guides to direct the fuel towards respective
reservoir.
[0020] In an aspect, each of the plurality of first reservoirs and the plurality of
10 second reservoirs initially defines slant shape for easy entry of fuel, then sharp
enclosed curve profile is provided at end to retain fuel at higher pressure for
prolong period, wherein the plurality of first reservoirs and the plurality of second
reservoirs are in shape of semi-cardioid.
[0021] In an aspect, the sealing portion is in semi-cardioid shape extended
15 outward from inclined surface of the conical shaped nozzle body.
[0022] In another embodiment, the present subject matter discloses a method
for operating a fuel Injector having an injector casing and an injector needle to
spray fuel at different stages into an engine cylinder, the injector needle coupled
with a solenoid for up down movement in the injector casing, where the solenoid
20 is being operated by an Engine Control Unit (ECU), the method comprising filling
fuel into a plurality of second reservoirs in the injector needle by moving up the
injector needle to open a sealing between a sealing portion of the injector needle
and internal surface of the injector casing to allow passage of the fuel towards the
plurality of second reservoirs and accumulation of pressurized fuel in the plurality
25 of second reservoirs; injecting fuel from the plurality of second reservoirs of the
injector needle by moving up the injector needle to align the plurality of second
reservoirs with a plurality of second orifices of the injector casing; filling fuel into
a plurality of first reservoirs in the injector needle by moving down the injector
needle to achieve partial sealing between the sealing portion of the injector needle
6
and internal surface of the injector casing leading to passage of the fuel towards
the plurality of first reservoirs and accumulation of pressurized fuel in the
plurality of first reservoirs; and injecting fuel from the plurality of first reservoirs
of the injector needle by moving up the injector needle to align the plurality of
5 first reservoirs with a plurality of first orifices of the injector casing.
[0023] In an aspect, the method includes the fuel is sprayed in sequential
order as the plurality of second orifices then the plurality of second orifices.
[0024] In an aspect, the method includes each of the plurality of first orifices
and the plurality of second orifices is surrounded by inclined guides to direct the
10 fuel towards respective reservoir with high pressure.
[0025] The above-disclosed aspects are advantageous in preparing a good
homogenous air-fuel mixture and helping in complete combustion, thereby
reducing the harmful emission of effluents. Further, the above-mentioned aspects
prevent cylinder wall and piston wall wetting/quenching.
15 [0026] In order to further understand the characteristics and technical contents
of the present subject matter, a description relating thereto will be made with
reference to the accompanying drawings. However, the drawings are illustrative
only but not used to limit the scope of the present subject matter.
[0027] Various objects, features, aspects, and advantages of the inventive
20 subject matter will become more apparent from the following detailed description
of preferred embodiments, along with the accompanying drawing figures in which
like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] It is to be noted, however, that the appended drawings illustrate only
25 typical embodiments of the present subject matter and are therefore not to be
considered for limiting of its scope, for the invention may admit to other equally
effective embodiments. The detailed description is described with reference to the
accompanying figures. The illustrated embodiments of the subject matter will be
best understood by reference to the drawings, wherein like parts are designated by
7
like numerals throughout. The following description is intended only by way of
example, and simply illustrates certain selected embodiments of devices, systems,
and methods that are consistent with the subject matter as claimed herein,
wherein:
5 [0029] FIG. 1a-1b illustrates structure of fuel injector having injector casing
and injector needle, in accordance with the present disclosure;
[0030] FIG. 1c illustrates guiding profile on plurality of orifices provided on
the injector casing of the fuel injector as shown in fig. 1b;
[0031] FIG. 1d illustrates profile of a plurality of reservoirs provided in the
10 injector needle of the fuel injector as shown in fig. 1b;
[0032] FIG. 1e illustrates structure and profile of a sealing portion provided
on the injector needle of the fuel injector as shown in fig. 1b;
[0033] FIG. 1f illustrates profile of cardioid of the plurality of reservoirs and
the sealing portion as shown in fig. 1d and 1e;
15 [0034] FIG. 1g illustrates spray angle of the plurality of orifices; and
[0035] FIG. 2a-2e illustrates a method for operating the fuel injector, in
accordance with the present disclosure.
[0036] The figures depict embodiments of the present subject matter for the
purposes of illustration only. A person skilled in the art will easily recognize from
20 the following description that alternative embodiments of the structures and
methods illustrated herein may be employed without departing from the principles
of the disclosure described herein.
DETAILED DESCRIPTION
[0037] The detailed description of various exemplary embodiments of the
25 disclosure is described herein with reference to the accompanying drawings. It
should be noted that the embodiments are described herein in such details as to
clearly communicate the disclosure. However, the amount of details provided
herein is not intended to limit the anticipated variations of embodiments; on the
8
contrary, the intention is to cover all modifications, equivalents, and alternatives
falling within the spirit and scope of the present disclosure as defined by the
appended claims.
[0038] It is also to be understood that various arrangements may be devised
5 that, although not explicitly described or shown herein, embody the principles of
the present disclosure. Moreover, all statements herein reciting principles, aspects,
and embodiments of the present disclosure, as well as specific examples, are
intended to encompass equivalents thereof.
[0039] The terminology used herein is for the purpose of describing particular
10 embodiments only and is not intended to be limiting of example embodiments. As
used herein, the singular forms “a”, “an” and “the” are intended to include the
plural forms as well, unless the context clearly indicates otherwise. It will be
further understood that the terms “comprises”, “comprising”, “includes” and/or
“including,” when used herein, specify the presence of stated features, integers,
15 steps, operations, elements and/or components, but do not preclude the presence
or addition of one or more other features, integers, steps, operations, elements,
components and/or groups thereof.
[0040] It should also be noted that in some alternative implementations, the
functions/acts noted may occur out of the order noted in the figures. For example,
20 two figures shown in succession may, in fact, be executed concurrently or may
sometimes be executed in the reverse order, depending upon the functionality/acts
involved.
[0041] Unless otherwise defined, all terms (including technical and scientific
terms) used herein have the same meaning as commonly understood by one of
25 ordinary skill in the art to which example embodiments belong. It will be further
understood that terms, e.g., those defined in commonly used dictionaries, should
be interpreted as having a meaning that is consistent with their meaning in the
context of the relevant art and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
9
[0042] The present subject matter as disclosed herein has multiplane injector
orifice design to assist spray from Orifices of Plane B and Plane A at different
instant with at a same time. Further, the present Injector has orifices at multi plane
with different set of diameters at each plane, with similar or different spray angle
5 with respect to each other and also each plane of orifices operated at different
time. Different orifices diameter over Nozzle body with narrow or wide spray
angle is provided to take advantage of early injection of fuel with variable spray
penetration to optimize combustion. This helps in Homogenous Air/Fuel mixture
formation inside combustion chamber at early crank angle BTDC (Before Top
10 Dead Center). Injection advance strategy helps in increasing the ignition delay,
thus providing surplus time for homogenous Air/fuel mixture formations inside
combustion chamber. Such fuel injection strategy also suffices for lower
temperature combustion and also for lower rate of Pressure rise, which otherwise
accounts for Noisy and Nox emission.
15 [0043] Injection methodology like Injection advance with Narrow spray angle
and bigger fuel droplets along with Injection retards with immense injection
pressure and smaller fuel droplets different is adopted to meet Emissions like Nox
and PM (soot) across all rated Engine load and all rated RPM, by avoiding
conventional diffusion base combustion. Also helps in Improving the after
20 treatment performance, by increasing the more percentage of CO and HC
concentration by utilising narrow Post injection strategy towards BDC.
[0044] In order to improve the homogeneity of an air-fuel mixture and reduce
cylinder wall and piston wall wetting, knocking and incomplete combustion the
present disclosure provides an improved fuel injector for injecting a fuel
25 preferably in a liquid state into a combustion chamber of the internal combustion
engine.
[0045] In FIG. 1a, 300 denotes the fuel injector which exhibits substantially a
cylindrical body. The fuel injector 300 is to be mounted into an injector bore of
the engine cylinder (not shown) and is capable to inject into the internal volume of
30 the engine cylinder. The fuel injector 300 comprises an injector needle 200 and an
10
injector casing 100. The injector needle 200 and an injector casing 100 are of
tubular cylindrical shape with a variable cross-section.
[0046] As shown in fig. 1a, the injector casing 100 defines a conical shaped
end portion with a vertex portion 100a and a base portion 100b. The injector
5 needle 200 defines a conical shaped nozzle body with a vertex portion 200a and
base portion 200b. The conical shaped end portion of the injector casing 100
encloses the conical shaped nozzle body of the injector needle 200. The injector
needle 200 moves up and down inside the injector casing 100.
[0047] The conical shaped end portion of the injector casing 100 comprises a
10 plurality of first orifices 101 and a plurality of second orifices 102 on
circumference of the conical shaped end portion. The plurality of first orifices 101
are defined at plane A and the plurality of second orifices 102 are defined at plane
B. In an embodiment, the plurality of first orifices 101 and the plurality of second
orifices 102 are defined at different planes. The plurality of second orifices 102
15 are located in between the plurality of first orifices 101 and the vertex portion
100a.
[0048] The conical shape nozzle body of the injector needle 200 comprises a
plurality of first reservoirs 201 and a plurality of second reservoirs 202 located on
circumference of the nozzle body. The plurality of first reservoirs 201 are located
20 at plane A and the plurality of second reservoirs 202 are located at plane B. The
plurality of second reservoirs located in between the plurality of first reservoirs
and the vertex portion. Further, a sealing portion is provided in between the
plurality of first reservoirs and the plurality of second reservoirs.
[0049] As shown in fig. 1a and 1b, the plurality of first orifices 101, the
25 plurality of second orifices 102 occupy angular positions around the
circumference of the conical shaped end portion of the injector casing and are
offset from the position occupied by each other and are evenly or discretely
distributed.
11
[0050] Similarly, the plurality of first reservoirs 201, the plurality of second
reservoirs 202 occupy angular positions around the circumference of the conical
shaped nozzle body of the injector needle 200 and are offset from the position
occupied by each other and are evenly or discretely distributed.
5 [0051] Both the orifices and reservoirs are corresponding to each other. For
example, the plurality of first orifices 101 corresponds to the plurality of first
reservoirs 201 in numbers and angular position. Similarly, the plurality of second
orifices 102 corresponds to the plurality of second reservoirs 202 in numbers and
angular position. In an embodiment, number of orifices in the plurality of first
10 orifices 101 and in the plurality of second orifices 102 on the conical shaped end
portion of the injector casing 100 are equal in number of reservoirs in the plurality
of first reservoirs 201 and in the plurality of second reservoirs 202 on the conical
shaped nozzle body of the injector needle 200, respectively.
[0052] In an embodiment, the plurality of first orifices and the plurality of
15 second orifices are offset to each other.
[0053] Diameter ‘Da’ (not shown in figures) of the plurality of first orifices
101 is less than diameter ‘Db’ (not shown in figures) of the plurality of second
orifices 102. Accordingly, pressure of fuel from the orifices varies. The plurality
of first reservoirs 201 defines volume ‘Va’ which is less than volume ‘Vb’ of the
20 plurality of second reservoirs 202.
[0054] As shown in fig. 1g, the plurality of first orifices 101 has a spray angle
(α) and the plurality of second orifices 102 has a spray angle (β) where the spray
angle (α) is greater the spray angle (β) or the spray angle (β) and the spray angle
(α) are same. The spray angle can be measured from central axis X of the fuel
25 injector 300.
[0055] As shown in the fig. 1c, each of the plurality of first orifices 101 and
the plurality of second orifices 102 are surrounded by inclined guides 102a, 102b
to direct the fuel towards respective reservoir. The inclined guides 102a, 102b also
12
avoids unwanted fuel spillage during injector needle movement in the injector
casing.
[0056] As shown in fig. 1d, each of the plurality of first reservoirs 201 and the
plurality of second reservoirs 202 firstly defines slant shape profile 201a, 202a for
5 easy entry of fuel, then sharp enclosed curve profile 201b, 202b is provided at end
to retain fuel at higher pressure for prolong period. The plurality of first reservoirs
201 and the plurality of second reservoirs 202 are in shape of semi-cardioid as
shown in fig. 1f.
[0057] As shown in fig. 1e, the sealing portion 203 is in semi-cardioid shape
10 (as shown in fig. 1f) extended outward from inclined surface of the conical shaped
nozzle body.
[0058] The Injecting pressure ‘Pa’ of the plurality of first orifices 101 is
greater than injecting pressure ‘Pb’ of the plurality of second orifices 102.
[0059] The injector casing 100 is connected to a feed passage for supplying
15 highly pressurized fuel into the injector needle 200. The fuel injector 100 is
configured to work or feed the fuel in multi stages during the compression stroke
of a piston in the engine cylinder. The fuel injector 100 is controlled by the
electronic control unit (ECU) based on the position of the piston in the engine
cylinder and predefine split injection or sequence injection. Further, the injection
20 strategies are based on the emissions improvement and the fuel economy. Further,
movement of the injector needle 200 in the injector casing 100 is done by a
solenoid which is controlled by Engine Control Unit (ECU) of the engine based
on the positon of the piston and load condition on the engine.
[0060] Figures 2a-2e defines working of fuel injector in different
25 conditions
[0061] As shown in fig. 2a, method 400 discloses No Fuel Flow in the injector
needle. As disclosed above that reservoirs have different volumes and orifices
have different diameter at Plane B and A, required to inject required quantity of
13
fuel with require Injection pressure to sustain combustion plays a prominent role
in better combustion and less emission. Nozzle needle movement is controlled
with respect to solenoidal actuation which is being controlled by the ECU and
differential pressure across fuel gallery. When there is no solenoid actuation, the
5 injector needle rests in its seat. During this period, the sealing portion 203 is fully
closed as shown by reference numeral 401, and no fuel flows to plurality of
second reservoirs 202. Hence there is no spray from Orifices of Plane B and Plane
A.
[0062] Referring to fig 2b showing fuel filling operation at the plurality of
10 second reservoirs 202 of the injector needle 200. For Fuel filling at the plurality of
second reservoirs 202, the injector needle 200 moves upward with the activation
of solenoid, travel of movement (lift) and duration (time) depends upon volume of
the plurality of second reservoirs 202 and path below the plurality of second
reservoirs 202 to fill completely with high pressure. At this instant, a sealing
15 between a sealing portion 203 of the injector needle 200 and internal surface of
the injector casing 100 is opened, as shown by reference numeral 402, to allow
passage of the fuel towards the plurality of second reservoirs 202 and
accumulation of pressurized fuel in the plurality of second reservoirs 202. Path of
fuel flow is designed with increasing volume (like diffuser), this results in
20 increasing the pressure and decreasing the velocity of fuel in the Path. Further, the
orifice guides 101a, 101b, 102a, 102b provided at every orifice help in directing
the fuel towards the plurality of second reservoirs 202, while fuel flow in
downward direction. The guides in orifices help in further building up the higher
pressure at plurality of second reservoirs 202. Apart from guiding the fuel, the
25 guides in orifices prevent untimely fuel spillage inside combustion chamber which
may otherwise can cause Emission and combustion related issue.
[0063] Referring to fig 2c showing fuel injection operation from the plurality
of second orifices 102 of the injector casing 100. For Injection from the plurality
of second orifices 102 of Plane B, the injector needle 200 moves further up. At the
30 same time the plurality of second reservoirs 202 is aligned, as shown by reference
14
numeral 403, to the plurality of second orifices 102 of Plane B, and thus fuel
injection happen from the plurality of second orifices 102. Due to high pressure
fuel accumulated at the plurality of second reservoirs 202, the pressure of fuel is
higher than pressure required to open the plurality of second orifices 102 at Plane
5 B. Hence, fuel injection happens from the plurality of second orifices 102. As
explained above, number of the plurality of second reservoirs 202 is available
circumferentially equal to numbers of the plurality of second orifices 102 at Plane
B for injecting the required quantity of fuel inside cylinder. In an embodiment,
Spray angle can be selected such that early injections/Injection advance advantage
10 can be utilized for Homogenous mixture formation without wall wetting or piston
wetting issue.
[0064] Referring to fig. 2d showing fuel filling operation at the plurality of
first reservoirs 201 at plane A. For Fuel filling operation at the plurality of first
reservoirs 201, the ECU sets the position of the injector needle 200 in downward
15 direction so that fuel passes through sealing is very less, as shown by the
reference numeral 404. This leads to fuel filling of gallery above the sealing
portion 203 and the plurality of second reservoirs 202 volume. The injector needle
200 is moved down to achieve partial sealing between the sealing portion 203 of
the injector needle 200 and internal surface of the injector casing 100 leading to
20 passage of the fuel towards the plurality of first reservoirs 201 and accumulation
of pressurized fuel in the plurality of first reservoirs 201.
[0065] Referring to fig. 2e showing fuel injection from the plurality of first
orifices of plane A of the injector casing. For Injection from the plurality of first
orifices 101 of Plane A of the injector casing 100, the ECU directs the injector
25 needle 200 position to move further up, so that the plurality of first reservoirs 201
is aligned to the plurality of first orifices 101 of Plane A, as shown by reference
numeral 405, and thus fuel injection happens from the plurality of first orifices
101 of the plane A. Due to high pressure fuel accumulated at the plurality of the
second reservoirs 202, the pressure of fuel at the plurality of first reservoirs 201 is
30 much higher than pressure required to open the plurality of first orifices 101 at
15
plane A. Hence injection happen. The plurality of first reservoirs 201 is available
circumferentially equal to numbers of the plurality of first orifices 101 at Plane A
for injecting the required quantity of fuel inside cylinder. Further, the Spray angle
may be selected such that early injections/Injection advance advantage can be
5 utilized for Homogenous mixture formation without wall wetting or piston
wetting issue.
[0066] In an embodiment, the Spray angle for the plurality of first orifices 101
at Plane A, can be same or different from the spray angle of the plurality of
second orifices 102 of Plane B.
10 [0067] This general formulation may be used as the basis for the designs of
the fuel injector to satisfy the requirements of the internal combustion engine and
the combustion chamber geometry. It should be appreciated that the components
and arrangements described herein may be applied by one skilled in the art to
various fuel injector designs, including but not limited to an electronically
15 controlled unit injector, a hydraulically-actuated electronically controlled unit
injector, a mechanically-actuated injector, or an injector coupled with a pump and
line fuel system, for example.
TECHNICAL ADVANTAGES
[0068] The present disclosure provides a fuel injector for injecting fuel into an
20 engine cylinder and a method for operating the fuel injector that prevents cylinder
wall and piston wall wetting/quenching.
[0069] The present disclosure provides a fuel injector and a method to operate
the fuel injector that facilitates the formation of a homogeneous air-fuel mixture.
[0070] The present disclosure provides a fuel injector and a method to operate
25 the fuel injector that reduces knocking and harmful emissions of effluents.
[0071] While the foregoing describes various embodiments of the present
disclosure, other and further embodiments of the present disclosure may be
devised without departing from the basic scope thereof. The scope of the
16
invention is determined by the claims that follow. The present disclosure is not
limited to the described embodiments, versions or examples, which are included
to enable a person having ordinary skill in the art to make and use the present
disclosure when combined with information and knowledge available to the
5 person having ordinary skill in the art.
LIST OF REFERENCE NUMERALS
300 Fuel injector
100 Injector casing
100a Vertex
10 100b Base portion
101 Plurality of first orifices
102 Plurality of second orifices
200 Injector needle
200a Vertex
15 200b Base portion
201 Plurality of first reservoirs
202 Plurality of second reservoirs
203 Sealing portion
400 Method for operating the fuel injector 300

We claim:

1. A fuel injector (300) for injecting a fuel into an engine cylinder, the fuel
injector (300) comprising:
an injector casing (100) defining a conical shaped end portion with a
5 vertex portion (100a) and a base portion (100b), the conical shaped end
portion of the injector casing (100) comprises:
a plurality of first orifices (101) and a plurality of second
orifices (102) on circumference of the conical end portion, the
plurality of second orifices (102) located in between the plurality of
10 first orifices (101) and the vertex portion (100a); and
an injector needle (200) defining a conical shaped nozzle body with a
vertex portion (200a) and base portion (200b), the conical shape nozzle
body comprises:
a plurality of first reservoirs (201) and a plurality of second
15 reservoirs (202) located on circumference of the nozzle body, the
plurality of second reservoirs (202) located in between the plurality of
first reservoirs (201) and the vertex portion (200a);
characterized in that
each reservoir from the plurality of first reservoirs (201) and the
20 plurality of second reservoirs (202) have its corresponding orifice
from the plurality of first orifices (101) and the plurality of second
orifices (102); and
a sealing portion (203) is provided in between the plurality of
first reservoirs (201) and the plurality of second reservoirs (202),
25 the conical shape nozzle body of the injector needle (200)
moves inside the conical end portion of the injector casing (100).
2. The fuel injector (300) as claimed in claim 1, wherein the fuel injector (300)
injects the fuel into the engine cylinder when:
18
the plurality of second orifices (102) in-line with the plurality of
second reservoirs (202); and
the plurality of first orifices (101) in-line with the plurality of first
reservoirs (201),
5 the plurality of second orifices (102) and the plurality of first orifices
(101) inject fuel at different time.
3. The fuel injector (300) as claimed in claim 1, wherein the plurality of first
reservoirs (201) and the plurality of second reservoirs (202) are provided on
single molded conical shape nozzle body of the injector needle (200).
10 4. The fuel injector (300) as claimed in claim 1, wherein diameter (Da) of the
plurality of first orifices (101) is less than diameter (Db) of the plurality of
second orifices (102).
5. The fuel injector (300) as claimed in claim 1, wherein volume (Va) of the
plurality of first reservoirs (201) is less than volume (Vb) of the plurality of
15 second reservoirs (202).
6. The fuel injector (300) as claimed in claim 1, wherein the plurality of first
orifices (101) and the plurality of second orifices (102) are offset to each
other.
7. The fuel injector (300) as claimed in claim 1, wherein number of orifices in
20 the plurality of first orifices (101) and in the plurality of second orifices
(102) on the conical shaped end portion of the injector casing (100) are
equal in number of reservoirs in the plurality of first reservoirs (201) and in
the plurality of second reservoirs (202) on the conical shaped nozzle body of
the injector needle (200), respectively.
25 8. The fuel injector (300) as claimed in claim 1, wherein the plurality of first
orifices (101) has a spray angle (α) and the plurality of second orifices (102)
has a spray angle (β), the spray angle (α) is greater the spray angle (β) or the
spray angle (β) and the spray angle (α) are same.
19
9. The fuel injector (300) as claimed in claim 1, wherein each of the plurality
of first orifice (101) and the plurality of second orifice (102) surrounded by
inclined guides to direct the fuel towards respective reservoir.
10. The fuel injector (300) as claimed in claim 1, wherein each of the plurality
5 of first reservoirs (201) and the plurality of second reservoirs (202) firstly
defines slant shape for easy entry of fuel, then sharp enclosed curve profile
is provided at end to retain fuel at higher pressure for prolong period,
wherein the plurality of first reservoirs (201) and the plurality of second
reservoirs (202) are in shape of semi-cardioid.
10 11. The fuel injector (300) as claimed in claim 1, wherein the sealing portion
(203) is in semi-cardioid shape extended outward from inclined surface of
the conical shaped nozzle body.
12. A method (400) for operating a fuel Injector (300) as claimed in claims 1-
11, the fuel injector (300) having an injector casing (100) and an injector
15 needle (200) to spray fuel at different stages into an engine cylinder, the
injector needle (200) coupled with a solenoid for up down movement in the
injector casing (100), where the solenoid is being operated by an Engine
Control Unit (ECU), the method (400) comprising:
filling (402) fuel into a plurality of second reservoirs (202) in the
20 injector needle (200) by moving up the injector needle (200) to open a
sealing between a sealing portion (203) of the injector needle (200) and
internal surface of the injector casing (100) to allow passage of the fuel
towards the plurality of second reservoirs (202) and accumulation of
pressurized fuel in the plurality of second reservoirs (202);
25 injecting (403) fuel from the plurality of second reservoirs (202) of the
injector needle (200) by moving up the injector needle (200) to align the
plurality of second reservoirs (202) with a plurality of second orifices (102)
of the injector casing (100);
filling (404) fuel into a plurality of first reservoirs (201) in the injector
30 needle (200) by moving down the injector needle (200) to achieve partial
sealing between the sealing portion (203) of the injector needle (200) and
20
internal surface of the injector casing (100) leading to passage of the fuel
towards the plurality of first reservoirs (201) and accumulation of
pressurized fuel in the plurality of first reservoirs (201); and
13. injecting (405) fuel from the plurality of first reservoirs (201) of the injector
5 needle (200) by moving up the injector needle (200) to align the plurality of
first reservoirs (201) with a plurality of first orifices (101) of the injector
casing (100). The method (400) as claimed in claim 12, wherein the fuel is
sprayed in sequential order as first the plurality of second orifices (101) then
the plurality of second orifices (102).
10 14. The method (400) as claimed in claim 12, wherein each of the plurality of
first orifices (101) and the plurality of second orifices (102) is surrounded
by inclined guides to direct the fuel towards respective reservoir with high
pressure.