The present disclosure relates generally to a fuel injector in a spark ignition engine for gaseous fuel. The present invention, in particular, relates to a fuel injector with variable turbulence control to improve emission performance and fuel economy.
BACKGROUND
[0002] A fuel injector is part of an engine's fuel delivery system that receives and sprays fuel into the spark ignition engine. In a spark ignition engine, during intake process, the fuel is injected from the injector and subsequently mixed with air before combustion in cylinder. Thereafter, piston inside the cylinder compresses the fuel-air mixture and a spark ignites causing combustion.
[0003] The air-fuel mixture is created during intake process for combustion and provide energy to the crankshaft which further directs this energy to rotate wheels and help in movement of vehicles using transmission.
[0004] FIG. 1 illustrates an exemplary fuel injector in accordance with existing art. The fuel injector 100 primarily comprises an injector body 101, a nozzle 102 and an injector needle 103. The injector body 101 has a defined fluid passage 101a with an inlet and an outlet. The nozzle 102 is in the form of a hollow barrel provided below the fluid passage 101a. The injector needle 103 is disposed in the fluid passage 101a. The injector needle 103 act as a valve and facilitate fuel flow from the nozzle 102. The injector needle 103 has a coil 104 provided around it operatively connected to the electronic control unit of the vehicle to actuate the injector needle 103. On actuation, the injector needle 103 facilitate fuel flow into engine port via the nozzle 102. Subsequently, air and fuel is mixed in the engine port. Nozzle acts as part to provide direction and turbulence to the gaseous fuel.

[0005] As the air-fuel mixture is created during intake process for combustion, it is necessary that the air-fuel mixture is homogeneous. Poor mixing of air and fuel directly affects the amount of energy given out by the engine. Further, poor mixing of air and fuel affects the lifespan of engine as it is not designed to burn un-mixed fuel. Thus, poor mixing of air and fuel affects the emission performance and fuel economy of the engine.
[0006] In the current injector design there is a hollow barrel nozzle with limited control for improving turbulence or injection direction. However, the turbulence created by the barrel nozzle 102 may not be enough to produce better air fuel homogeneity.
[0007] Usually, intake process is a very quick process and homogeneous mixing of air and fuel is not possible due to short interval between one injection to another injection and lack of space for mixing of air and fuel. Further engine demand changes as per the requirement of driver, and the intake process has to adjust itself as per the engine demand.
[0008] Accordingly, there is a need for a fuel injector with variable turbulence control based on engine demand to create air-fuel mixture with better air-fuel homogeniety resulting in improved emission performance and fuel economy.
SUMMARY
[0009] This summary is provided to introduce concepts related to a fuel injector with variable turbulence control. The concepts are 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.
[0010] The present disclosure relates to a fuel injector with variable turbulence control. The fuel injector comprises an injector body, a nozzle and an injector needle. The injector body has a defined fluid passage with an inlet and an outlet. The nozzle is provided below the fluid passage adapted to provide a turbulence

chamber for generating pressure and turbulence in fuel. The injector needle is provided in the fuel passage. The injector needle is adapted to facilitate fuel flow into the nozzle. The nozzle is provided with a movable insert adapted to move inside the nozzle in a first position and a second position to create variable turbulence and pressure based on engine demand.
[0011] In an aspect, the movable insert has non-uniform helical threads to increase turbulence and pressure for mixing of fuel and air.
[0012] In an aspect, magnetic coil is provided around the nozzle operatively connected to a controller to move the movable insert inside the nozzle in the first position and the second position.
[0013] In an aspect, the controller actuates the magnetic coil to move the movable insert in the first position when the engine speed and load demand is low.
[0014] In an aspect, the controller actuate the magnetic coil to move the moving insert in the second position when the engine speed and load demand is high.
[0015] In an aspect, a coil is provided around the fluid passage operatively connected to electronic control unit to actuate injector needle to facilitate fuel flow through the nozzle.
[0016] In an aspect, when the engine load demand is low and the moving insert is in first position, an ancillary space is created in the nozzle to enhance fuel path to enhance turbulence and pressure in the fuel.
[0017] In an aspect, when the engine load demand is high and the moving insert is in second position, the air-fuel mixture from the movable insert is directly inducted into the engine port for generation of homogeneous air-fuel mixture.
[0018] 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.

[0019] Various objects, features, aspects, and advantages of the inventive 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 FIGURES
[0020] The illustrated embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:
[0021] FIG. 1 illustrates an exemplary fuel injector in accordance with existing art;
[0022] FIG. 2 illustrates sectional view of an exemplary fuel injector with variable turbulence control that can be utilized to implement one or more exemplary embodiments of the present disclosure;
[0023] FIG. 3 illustrates sectional view of an exemplary non-uniform helical thread that can be utilized to implement one or more exemplary embodiments of the present disclosure and section view of an exemplary uniform helical thread in accordance with existing art;
[0024] FIG. 4a illustrates sectional view of the nozzle of an exemplary fuel injector, with movable insert in first position, that can be utilized to implement one or more exemplary embodiments of the present disclosure; and
[0025] FIG. 4b illustrates sectional view of the nozzle of an exemplary fuel injector, with movable insert in second position that can be utilized to implement one or more exemplary embodiments of the present disclosure.
[0026] 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

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
[0027] A few aspects of the present disclosure are explained in detail below with reference to the various figures. Example implementations are described to illustrate the disclosed subject matter, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a number of equivalent variations of the various features provided in the description that follows.
EXEMPLARY IMPLEMENTATIONS
[0028] While the present disclosure may be embodied in various forms, there are shown in the drawings, and will hereinafter be described, some exemplary and non-limiting embodiments, with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated. Not all of the depicted components described in this disclosure may be required, however, and some implementations may include additional, different, or fewer components from those expressly described in this disclosure. Variations in the arrangement and type of the components may be made without departing from the scope of the claims as set forth herein.
[0029] In order to achieve this goal of generating a mixture of air and fuel with better air-fuel homogeneity during intake process, a fuel injector with variable turbulence control may be utilized. The fuel injector with variable turbulence control is described in more detail below:
[0030] FIG. 2 illustrates sectional view of an exemplary fuel injector with variable turbulence control that can be utilized to implement one or more exemplary embodiments of the present disclosure. The fuel injector 200 with variable

turbulence and pressure control comprises an injector body 201, a nozzle 202 and an injector needle 203. The injector body 201 has a fluid passage 204 with an inlet and an outlet. The fluid passage 204 is defined for the flow of fuel. The injector needle 203 is provided in the fluid passage 204. The injector needle 203 act as a valve and facilitate fuel flow from the nozzle 202. The injector needle 203 has a coil 205 provided around it operatively connected to the electronic control unit of the vehicle to actuate the injector needle 203. On actuation, the injector needle 203 facilitate fuel flow into engine port via the nozzle 202. The nozzle 202 is provided below the fluid passage to provide direction and turbulence to the gaseous fuel.
[0031] To create effective turbulence and pressure for producing mixture of fuel and air by the nozzle 202 with better homogeneity, a movable insert 206 is provided inside the nozzle 203. This movable insert 206 has non-uniform helical threads 206a. These non-uniform helical threads 206a increase the turbulence and pressure in the fuel for better mixing of fuel with air in the engine port. Further, the movable insert 206 is adapted to move inside the nozzle 202 in a first position and a second position to create variable turbulence and pressure based on engine demand. A magnetic coil 207 is provided around the nozzle 202. The magnetic coil 207 is operatively connected to a controller. The controller is configured to actuate the magnetic coil 207 and move the movable insert 206 inside the nozzle 202 in the first position and the second position as per the engine demand.
[0032] FIG. 3 illustrates sectional view of an exemplary non-uniform helical thread that can be utilized to implement one or more exemplary embodiments of the present disclosure and section view of an exemplary uniform helical thread in accordance with existing art. A comparison of pressure is shown between uniform helical threads and non-uniform helical threads 206a. In the existing uniform helical thread provided in the nozzle, the distance between two consecutive helical threads is kept constant. Accordingly, the helical threads are uniformly distributed at the inlet as well as at the outlet of the nozzle. This results in same fuel pressure at the inlet and at the outlet (shown as X). Uniform helical threads limitedly increase the turbulence which results in mixing of air and fuel to a limited extent. In the proposed

non-uniform helical thread 206a provided in the nozzle 202, the distance between two consecutive helical threads is variable. Accordingly, the helical threads 206a are non-uniformly distributed at the inlet as well as at the outlet. The number of helical threads 206a provided at the outlet is more than the number of helical threads 206a provided at the inlet. This results in additional pressure and turbulence at the outlet than at the inlet. Non-uniform helical threads 206a increase the pressure and turbulence which results in better mixing of air and fuel.
[0033] FIG. 4a illustrates sectional view of the nozzle of an exemplary fuel injector, with movable insert in first position that can be utilized to implement one or more exemplary embodiments of the present disclosure. In the section view, the movable insert 206 is shown in first position. When the engine speed and load demand is low, the controller actuates the magnetic coil 207 to move the movable insert 206 in the nozzle 202 towards the injector needle 203 direction (first position). In the first position, an ancillary space 208 is created in the nozzle 202 to provide enhanced fuel path resulting in generation of turbulence and pressure in the fuel. The generation of enhanced turbulence and pressure in the fuel from the nozzle 202 results in better mixing of air and fuel in the engine port. The air-fuel mixture with better homogeneity from the engine port is then injected into the cylinder for combustion. Thus, during low engine speed and load demand, the fuel injector 200 is adapted to create air-fuel mixture with better homogeneity.
[0034] FIG. 4b illustrates sectional view of the nozzle of an exemplary fuel injector, with movable insert in second position that can be utilized to implement one or more exemplary embodiments of the present disclosure. In the section view, the movable insert 206 is shown in second position. When the engine speed and load demand is high, the controller actuates the magnetic coil 207 to move the movable insert 206, in the nozzle 202, towards the outlet of the nozzle 202 (second position). The non-uniform helical threads 206a in the movable insert 206 which is in the second position, generates turbulence and pressure in the fuel. This fuel with enhanced turbulence and pressure is then injected into the engine port to create air-fuel mixture with better homogeneity. The air-fuel mixture with better homogeneity

is then injected into the cylinder for combustion. Thus, during high engine speed and load demand, the fuel injector 200 is adapted to create air-fuel mixture with better homogeneity.
WORKING OF THE PREFERRED EMBODIMENT
[0035] During Low Engine Speed and Load Demand: When there is demand for fuel injection in the cylinders of an engine, the electronic control unit actuates the coil 25 to facilitate flow of fuel into the nozzle 202. When the engine speed and load demand is low, the controller actuates the magnetic coil 207 and the movable insert 206 is moved in first position. The fuel is injected in the movable insert 206. The non-uniform helical insert 206a enhances pressure and turbulence of the fuel. After passing through the non-uniform helical threads 26a of the movable insert 206, the fuel arrive at the ancillary space where due to enhanced fuel path, the pressure and turbulence in the fuel is enhanced. The fuel with enhanced turbulence and pressure is then injected into the engine port where air-fuel mixture with better homogeneity is generated. The air-fuel mixture with better homogeneity is subsequently injected through the valve into the cylinder for combustion.
[0036] During High Engine Speed and Load Demand: When there is demand for fuel injection in the cylinders of an engine, the electronic control unit actuates the coil 205 to facilitate flow of fuel into the nozzle 202. When the engine speed and load demand is high, the controller actuates the magnetic coil 207 and the movable insert 206 is moved in second position. The fuel is injected in the movable insert 206. The non-uniform helical threads 206a in the movable insert 206 enhance pressure and turbulence of the fuel . Afterwards, the fuel with enhanced pressure and turbulence is injected into the engine ports where air-fuel mixture with better homogeneity is generated. The air-fuel mixture with better homogeneity is subsequently injected through the valve into the cylinder for combustion.
ADVANTAGES
[0037] The proposed fuel injector with variable turbulence and pressure control creates air-fuel mixture with better air-fuel homogeniety resulting in improved

emission performance and fuel economy. With the proposed non-uniform helical threads, the turbulence in the movable insert has been increased which results in production of better air-fuel mixture homogeneity. Further, with proposed movable insert, variable turbulence is created based on engine speed and load demand.
[0038] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[0039] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0040] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0041] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

We Claim:

1. A fuel injector (200) with variable turbulence control, the fuel injector (200)
comprises:
an injector body (201) having a defined fluid passage (204) with an inlet and an outlet;
a nozzle (202) provided below the fluid passage (204) adapted to provide a turbulence chamber for generating pressure and turbulence in fuel; and
an injector needle (203) provided in the fluid passage (204), wherein the injector needle (203) is adapted to facilitate fuel flow into the nozzle (202);
characterized in that
the nozzle (202) is provided with a movable insert (206) adapted to move inside the nozzle (202) in a first position and a second position to create variable turbulence and pressure based on engine demand.
2. The fuel injector (200) as claimed in claim 1, wherein the movable insert
(206) has non-uniform helical threads (206a) to increase turbulence and
pressure for mixing of fuel and air.
3. The fuel injector (200) as claimed in claim 1, wherein a magnetic coil (207)
is provided around the nozzle (202) operatively connected to a controller to
move the movable insert (206) inside the nozzle (202) in the first position
and the second position.

4. The fuel injector (200) as claimed in claim 3, wherein the controller actuates the magnetic coil (207) to move the movable insert (206) in the first position when the engine speed and load demand is low.
5. The fuel injector (200) as claimed in claim 3, wherein the controller actuates the magnetic coil (207) to move the moving insert (206) in the second position when the engine speed and load demand is high.
6. The fuel injector (200) as claimed in claim 1, wherein a coil (205) is provided around the fluid passage (204) operatively connected to electronic control unit to actuate injector needle (203) to facilitate fuel flow through the nozzle (202).
7. The fuel injector (200) as claimed in claim 4, wherein when the engine load demand is low and the moving insert (206) is in first position, an ancillary space (208) is created in the nozzle (202) to enhance fuel path to increase turbulence and pressure in the fuel.
8. The fuel injector (200) as claimed in claim 5, wherein when the engine load demand is high and the moving insert (206) is in second position, the fuel from the movable insert (206) with enhanced turbulence and pressure is directly injected into engine port for generation of homogeneous air-fuel mixture.