DESC:DISCLAIMER
[0001] Portions of this patent document may contain material that may be subject to Copyright or Trademark protection. The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office file or records, but otherwise reserves all copyright rights and trademarks whatsoever. All copyrights and trademarks are owned by Indian Institute of Science, Bangalore.

TECHNICAL FIELD
[0002] The present disclosure relates in general to spark plugs for internal combustion (IC) engines. More particularly, the present disclosure relates to an igniter assembly with a pre-combustion chamber for an internal combustion (IC) engine.

BACKGROUND
[0003] The information in this section merely provides background information related to the present disclosure and may not constitute prior art(s) for the present disclosure.
[0004] Greenhouse gas emissions mitigation has brought forth a focus on enhancing fuel energy efficiency. Internal combustion (IC) engines, being extensively used in automotive and industrial applications, represent a significant target for improving their fuel efficiency and reducing emissions. One effective method to enhance the efficiency of the IC engines is by increasing their compression ratio, which directly impacts their thermodynamic cycle efficiency and subsequently improves fuel economy.
[0005] However, a challenge arises when attempting to implement higher compression ratios in spark-ignited IC engines. As the compression ratio increases, so does the propensity for a phenomenon known as knocking. Knocking occurs when uncontrolled combustion pockets within an engine cylinder generate excessive pressure waves, leading to detrimental effects such as engine damage and reduced performance.
[0006] One approach to mitigate knocking in high compression ratio spark-ignited engines is to operate the engine at lean air-fuel mixtures. Lean operation helps in reducing the peak temperatures and pressures within the combustion chamber, thereby reducing the likelihood of knocking. However, igniting such lean mixtures poses a significant challenge, particularly as an equivalence ratio approaches a lean combustion limit of the fuel. At extremely lean conditions, conventional ignition systems struggle to initiate combustion reliably.
[0007] Efforts to address the above constraints have been explored in the below prior-arts. For instance, in a patent application CN108060971B relating to pre-chamber ignition systems, methods and systems for a pre-chamber ignition system are described. The pre-chamber ignition system comprises a pre-chamber extending into the combustion chamber, a piston protrusion shaped to fit through a bottom opening of the pre-chamber, and a plurality of apertures formed by a side wall of the pre-chamber. A method for a pre-chamber ignition system includes adjusting spark timing within the pre-chamber, and pressing projections into the pre-chamber to ignite air/fuel within the main combustion chamber. However, the above methods and systems has limitations as the methods and systems are used on the pre-chamber ignition system. However, this concept is similar to a passive pre-chamber system where a piston and a cylinder head form a closed volume, when the piston is at a Top Dead Centre (TDC) and air-fuel mixture in it will be ignited by a spark plug. Further, the burnt gases come out through holes on the side of this pre-chamber.
[0008] In an application US10337397B2, a method and a system are provided for purging a pre-chamber. The system is provided with a combustion chamber formed by a cylinder head coupled to a cylinder block, and a pre-chamber in fluidic communication with the combustion chamber. The system further includes a purge port coupled to the pre-chamber and structured to flow purge air into the pre-chamber, where the flow of the purge air is driven by operation of a purge pump and a piston disposed within the combustion chamber. However, the method and the system have its limitations as the method and the system are based on an active pre-chamber igniter. The method and the system pertain to a separate injector for introducing fuel into the pre-chamber. Further, the pre-chamber is supplied with fresh air.
[0009] In an application US9353674B2, an ignition system for an internal combustion engine having at least one combustion chamber is disclosed. The ignition system includes a housing, an ignition device, an injector, and a pre-chamber having a nozzle spaced from a proximal portion of the pre-chamber. The igniter portion of the ignition device and the nozzle of the injector are operatively supported in the proximal portion of the pre-chamber and disposed flush therewith. The igniter portion ignites the fuel in the pre-chamber such that partially combusted pre-chamber products are forced through orifices in the pre-chamber nozzle and extinguished but dispersed through the combustion chamber to ignite the main fuel charge therein. However, the above prior arts have limitations as the ignition system pertains to an active pre-chamber igniter which uses a high-pressure direct injector for fuel injection where the engine loses more energy to generate high pressure, thereby making the engine less efficient.
[0010] There is, therefore, a requirement in the art to overcome the above-mentioned problems by providing a simple, compact, and efficient igniter assembly with a pre-combustion chamber for an internal combustion engine.

OBJECTS OF THE PRESENT DISCLOSURE
[0011] A general object of the present disclosure is to overcome the problems associated with existing spark plug for internal combustion (IC) engines, by providing a simple, compact, cost-effective, and efficient igniter assembly with a pre-combustion chamber for an internal combustion (IC) engine.
[0012] Another object of the present disclosure is to provide a pre-combustion chamber having a volume of 5 to 30 percent of the volume of the IC engine’s combustion chamber.
[0013] Yet another object of the present disclosure is to provide an assembly that generates plume of heated air-fuel mixture for ignition of fuel within the IC engine’s cylinder.
[0014] Yet another object of the present disclosure is to provide an assembly that generates one or more electrical pulses between a nanosecond to microsecond.
[0015] Yet another object of the present disclosure is to provide an assembly which prevents backflow of fuel from the injector into the fuel injector assembly.

SUMMARY
[0016] This section is provided to introduce certain objects and aspects of the present disclosure in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.
[0017] According to an aspect, the igniter assembly for an internal combustion (IC) engine is configured on a cylinder of the IC engine. The assembly includes a housing having a pre-combustion chamber. The housing is in a fluidic communication with a low-pressure fuel injector assembly through a thin fuel pipe having a diameter that is between a range of 0.5 mm to 3 mm.
[0018] The assembly includes a low-inertia non-return valve configured on the thin fuel pipe to inject fuel at a low pressure that is between a range of 3 bar to 10 bar into the pre-combustion chamber of the housing while preventing backflow of the fuel into the fuel injector assembly such that the low-inertia non-return valve and the thin fuel pipe enables the fuel to be injected at low-pressure.
[0019] The assembly includes a spark plug configured on the housing such that the fuel received into the pre-combustion chamber mixes with air that is received into the pre-combustion chamber to form a first air-fuel mixture therein, which upon ignition by the spark plug, during a compression stroke of the IC engine, generates hot burnt gases or flames in the pre-combustion chamber, where due to pressure generated within the pre-combustion chamber during combustion forces the generated hot burnt gases or flames through one or more orifices of the housing to form one or more combustion plumes. The combustion plumes enter a main combustion chamber of the cylinder, thereby igniting a pre-stored second air-fuel mixture therewithin.
[0020] In an embodiment, the housing may have a first end and a second end. The housing may be configured on at least one port on the cylinder of the IC engine from the second end.
[0021] In an embodiment, the housing may include a first port. The first port may be configured on the first end of the housing to facilitate mounting of the spark plug.
[0022] In an embodiment, the housing may include a second port. The second port may be configured on the housing between the first end and the second end to receive the fuel into the pre-combustion chamber from the fuel injector assembly.
[0023] In an embodiment, the fuel injector assembly may be configured on the housing between the first end and the second end. The fuel injector assembly may establish a fluidic communication with the housing.
[0024] In an embodiment, the spark plug may be configured on the housing. The spark plug may generate one or more electrical pluses.
[0025] In an embodiment, the one or more orifices may be configured on the second end of the housing. The one or more orifices may generate one or more plumes. The plasma generated upon igniting the first air-fuel mixture may be forced through the one or more orifices into the cylinder of the IC engine.
[0026] In an embodiment, the one or more orifices may include a predefined diameter. The predefined diameter may be selected between a range of 1 mm to 2 mm.
[0027] In an embodiment, the assembly may include a thermally insulating component configured on an inner wall at the second end of the housing. The thermal insulating component may thermally insulate the housing. The thermal insulating component may be a ceramic insert or a double walled portion at the second end of the housing.
[0028] In an embodiment, the volume of the pre-combustion chamber of the housing may be selected between a range of 5 percent to 30 percent of a volume of a combustion chamber of the cylinder.
[0029] In an embodiment, the assembly may include an electronic control unit (ECU) associated with the IC engine. The ECU may be adapted to actuate the spark plug for generating one or more electrical pulses within a predefined time period. The predefined time period may be selected between a range of one nanosecond to one microsecond.
[0030] In an embodiment, the ECU may be in communication with the fuel injector assembly to actuate the fuel injector assembly for injecting the fuel into the pre-combustion chamber of the housing at a predefined pressure. The predefined pressure may be selected between a range of 3 bar to 10 bar.
[0031] In an embodiment, the thin fuel pipe may be configured on the second port of the housing.
[0032] 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
[0033] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0034] FIGs. 1A and 1B illustrate schematic views of the igniter assembly, in accordance with an embodiment of the present disclosure.
[0035] FIGs. 2A and 2B illustrate a schematic view of a pre-combustion chamber of the igniter assembly, in accordance with an embodiment of the present disclosure.
[0036] FIG. 3 illustrates a sectional view of the assembly with a non-return valve, in accordance with an embodiment of the present disclosure.
[0037] FIG. 4 illustrates schematic representations depicting a sequence of images at different timings starting from a time of spark, in accordance with an embodiment of the present disclosure.
[0038] FIG. 5 a graphical representation depicting a comparison between pressure rise in a constant volume combustion chamber (CVCC) and a time, in accordance with an embodiment of the present disclosure.
[0039] Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure.

DETAILED DESCRIPTION
[0040] Hereinafter, various exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings, where it should be understood that all these drawings and description are only presented as exemplary embodiments. It is to be noted that based on the subsequent description, several alternative embodiments may be conceived that may have a structure similar to that disclosed herein and/or formed by a method as disclosed herein, and all such alternative embodiments may be used without departing from the principle of the disclosure as claimed herein, and hence such alternative embodiments are construed to fall within the scope of the present disclosure.
[0041] All references in the specification made to “one embodiment,” “an embodiment,” “a preferred embodiment” etc., indicate that the embodiment described herein may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases may not be necessarily referring to the same embodiment. It should also be understood that various terminology used herein is for the purpose of describing a particular embodiment or specific embodiments only and the use of such terminology is not intended to be limiting the scope and spirit of the present disclosure. As used herein, the singular forms “a,” “an” and “the” may also include the plural forms, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “has” and “including” used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence of one or more other features, elements, components and/or a combination thereof. For example, the term “multiple” used here indicates “two or more;” the term “and/or” used here may comprise any or all combinations of one or more of the items listed in parallel. Definitions of other terms will be specifically provided in the following description. Furthermore, in the following description, some functions, or structures well-known to those skilled in the art will be omitted in order not to obscure embodiments of the disclosure in the unnecessary details.
[0042] It may be appreciated that these exemplary embodiments are provided only for enabling those skilled in the art to better understand and then further implement the present disclosure, not intended to limit the scope of the present disclosure in any manner. Besides, in the drawings, for a purpose of illustration, optional steps, modules, and units may be illustrated in dotted-line blocks.
[0043] Exemplary embodiments of the present disclosure relate to an igniter assembly with a pre-combustion chamber for an internal combustion (IC) engine.
[0044] According to an aspect, the igniter assembly configured on a cylinder of the IC engine includes a housing connected to a low-pressure fuel injector assembly through a thin fuel pipe having 0.5 mm to 3 mm diameter. A low-inertia non-return valve configured on the thin fuel pipe to inject fuel at 3 bar to 10 bar pressure into the pre-combustion chamber of the housing while preventing backflow of the fuel into the fuel injector assembly. A spark plug configured on the housing ignites a first air-fuel mixture therein to generate hot burnt gases or flames in the pre-combustion chamber which are forced through one or more orifices of the housing to form one or more combustion plumes that enters a main combustion chamber of the cylinder, thereby igniting a pre-stored second air-fuel mixture therewithin.
[0045] The igniter assembly may include the housing having a pre-combustion chamber in a fluidic communication with the fuel injector assembly that may be adapted to inject the fuel into the pre-combustion chamber of the housing at a low pressure (3 bar to 10 bar).
[0046] The combustion of the air-fuel mixture may take place in the pre-combustion chamber of the housing. The pre-combustion chamber’s volume may be selected between a range of 5 percent to 30 percent of a volume of the IC engine’s combustion chamber. The pre-combustion chamber of the housing may be isolated from the combustion chamber of the IC engine. The pre-combustion chamber’s volume may be selected between a range from 1 cc to 8 cc or from 5% to 30% of the combustion chamber (clearance volume of the cylinder of the IC engine when a piston within the cylinder is at a Top Dead Center (TDC).
[0047] The housing having a clearance volume may be separated from the IC engine’s cylinder by a metal wall and may be further connected to the cylinder through one or more orifices that may include a series of small holes in a size range of 1 to 2 mm. The size, number, and orientation of the holes on the one or more orifices may be optimized based on the size of the combustion chamber and a location of the assembly on the IC engine’s cylinder. The size of the assembly may be bigger such that insulation like a ceramic insert or a double wall may be used to reduce heat losses.
[0048] In addition, the igniter assembly may include a spark plug that is configured on the housing for generating one or more electrical pulses. The spark plug may be configured on the housing, such that the fuel received in the pre-combustion chamber mixes with an air received into the pre-combustion chamber to form a first air-fuel mixture therein, which upon ignition by the spark plug, during a compression stroke of the IC engine, generates plasma. The fuel injector assembly may force the generated plasma through the one or more orifices of the housing to form one or more plumes in the cylinder of the IC engine to thereby ignite a pre-stored second air-fuel mixture therewithin. The one or more orifices may be configured on a second end of the housing to generate one or more plumes when the plasma generated upon igniting the first air-fuel mixture is forced through the one or more orifices into the cylinder of the IC engine. The one or more orifices may be formed of a predefined diameter between a range of 1 mm to 2 mm.
[0049] Further, the assembly may include a thermally insulating component configured on inner walls at the second end of the housing for thermal insulation of the housing. The thermal insulating component may be a ceramic insert or a double walled portion at the second end of the housing. An electrode of the spark plug may be exposed within the pre-combustion chamber of the housing to generate one or more electrical pulses. The electrical pulses generated by the spark plug may be either a conventional spark or a Nano-second Pulse Discharge (NPD) as required. Moreover, the assembly may include an electronic control unit (ECU) associated with the IC engine. The ECU may be adapted to actuate the spark plug for generating one or more electrical pulses within a predefined time having a range between one nanosecond to one microsecond.
[0050] Further, the assembly may include a fuel pipe to supply a metered quantity of fuel into the pre-combustion chamber. The fuel pipe may be connected to the fuel injector assembly through a non-return valve. The diameter and length of the fuel pipe may be optimized such that the reverse flow of hot plasma from the pre-combustion chamber into the fuel pipe may be prevented, allowing the fuel to flow at a faster rate from the fuel injector assembly to the pre-combustion chamber. Furthermore, the non-return valve may include O-rings which make the assembly cost-effective and reliable. In an exemplary embodiment, while in case of liquid fuels, the fuel pipe may be equipped with a heater to evaporate the injected fuel while entering the pre-combustion chamber to facilitate quicker combustion of the air-fuel mixture within the pre-combustion chamber.
[0051] Various embodiments of the present disclosure will be explained in detail with reference to FIGs. 1A-5.
[0052] Referring to FIGs. 1A to 5, an igniter assembly 100 may include a housing 102 having a pre-combustion chamber. The housing 102 may include a first end 102A and a second end 102B. The second end 102B of the housing 102 may be operatively coupled to a cylinder 200 of an internal combustion (IC) engine. The second end 102B of the housing 102 may be configured within the cylinder 200 of the IC engine. The pre-combustion chamber of the housing 102 may generate flames from a lean first air-fuel mixture. The pre-combustion chamber of the housing 102 may receive fuel from the first end 102A and air from the second end 102B. The second end 102B may receive air from the cylinder 200 during a compression stroke. In an exemplary embodiment, the housing 102 may include metal walls that may withstand high temperatures.
[0053] In an embodiment, the housing 102 may be configured for thoroughly mixing the first air and the first fuel entered into the pre-combustion chamber of the housing 102 to generate plasma of the first air-fuel mixture.
[0054] In some embodiments, one or more orifices 110 may be operatively coupled to the housing 102. The orifices 110 may be configured on the second end 102B of the housing 102. The orifices 110 may generate one or more plumes 104 from the generated plasma of the first air-fuel mixture forced out of the pre-combustion chamber of the housing 102 through the one or more orifices 110. The plumes 104 may ignite the second air fuel mixture within the cylinder 200 of the IC engine.
[0055] In some embodiments, a first port 114 may be operatively coupled to the housing 102. The first port 114 may be configured on a wall of the housing 102. The first port 114 may receive fuel into the housing 102 from a fuel injector assembly 106. The size of the housing 102 may be, for example, between a range of 1 cc to 8 cc.
[0056] In an embodiment, the size of the housing 102 may be, for example, between a range of 5% to 30% of a combustion chamber volume within the cylinder 200 of the IC engine. The shape of the housing 102 may be selected based on a space availability and heat loss in the cylinder 200 of the IC engine. The inner walls of the housing 102 may be insulated using a ceramic insert 112-1 or by using a double wall 112-2 such that a provision to mount a spark plug 108 and the thin fuel pipe 118 may be provided on the housing 102 of the assembly 100, as illustrated in FIGs. 1A to 3.
[0057] In an embodiment, the fuel injector assembly 106 may be in fluidic communication with the housing 102. The fuel injector assembly 106 may be configured on the housing 102 to inject fuel into the pre-combustion chamber. The fuel injector assembly 106 may be in communication with an ECU 202 of the IC engine. The ECU 202 may be configured to actuate the fuel injector assembly 106 upon sensing that the exhaust gases have been scavenged out from the cylinder 200 of the IC engine to inject fuel within a specific time period that may be, for example, between a range of one nanosecond to one microsecond at a predefined pressure. The predefined pressure may be, for example, between the range of 3 bar to 8 bar. The fuel injector assembly 106 may be, for example, a solenoid fuel injector assembly 106. In an exemplary embodiment, the solenoid fuel injector assembly 106 may inject a quantity of fuel at the predefined pressure within the predefined time period. The predefined time of fuel injection operation may be controlled by the ECU 202.
[0058] In an embodiment, the assembly 100 may include the spark plug 108 that may be operatively coupled to the housing 102. The spark plug 108 may be configured on the first end 102A of the housing 102. The spark plug 108 may ignite the air-fuel mixture within the housing 102. The ignition of the air-fuel mixture within the pre-combustion chamber of the housing 102 may increase the pressure within the pre-combustion chamber of the housing 102. The pressure built within the pre-combustion chamber upon ignition of the spark plug 108 may force the plasma generated within the pre-combustion chamber into the cylinder 200 of the IC engine. The one or more plumes 104 gushing into the cylinder 200 of the IC engine may ignite a second air-fuel mixture within the combustion chamber of the cylinder 200. The spark plug 108 may ignite the air-fuel mixture within the pre-combustion chamber at an end of a compression stroke inside the cylinder 200 of the IC engine. The spark plug 108 may be actuated for generating one or more electrical pulses within a predefined time period. The timing of generation of the electrical pulse by the spark plug 108 may be optimized by an electronic signal from the ECU 202. The electrical pulse generated by the spark plug 108 may be, for example, a conventional spark or a special spark by using a nanosecond pulse generator (NPD) which enhances lean combustion limit of the mixture.
[0059] In an embodiment, the ECU 202 may be provided in communication with the assembly 100. The ECU 202 may be configured to control a crank angle, a temperature, and a pressure of the fuel. The ECU 202 may be configured to actuate the spark plug 108 and the fuel injector assembly 106.
[0060] In an embodiment, the assembly 100 may include a thin fuel pipe 118 in fluidic communication between the first port 114 of the housing 102 and the fuel injector assembly 106. The thin fuel pipe 118 may be configured on the first port 114 of the housing 102 to enable the flow of the fuel from the fuel injector assembly 106 into the pre-combustion chamber. The thin fuel pipe 118 may be further configured to prevent the hot plasma generated within the pre-combustion chamber due to ignition of the air-fuel mixture from entering the fuel injector assembly 106.
[0061] In an embodiment, the assembly 100 may include a low-inertia non-return valve 120. The low-inertia non-return valve 120 may be operatively coupled between the housing 102 and the fuel injector assembly 106. The low-inertia non-return valve 120 may be configured on the thin fuel pipe 118. The low-inertia non-return valve 120 may prevent the backflow of the fuel into the fuel injector assembly 106. The low-inertia non-return valve 120 may further insulate the fuel injector assembly 106 from high temperatures of the pre-combustion chamber of the housing 102. The low-pressure fuel flowing from the fuel injector assembly 106 and the insulation may protect the fuel injector assembly 106 from high pressure and high temperature due to combustion operation within the pre-combustion chamber of the housing 102. In an exemplary embodiment, the low-inertia non-return valve 120 may use sealants like, for example, rubber O-rings, or rubber bushes which may not be manufactured using precision manufacturing technology. Further, a stopper weight and a spring strength of the low-inertia non-return valve 120 may be optimized for making the low-inertia non-return valve 120 more responsive, and eliminating a need for using the precision manufacturing technology, thereby making the non-return valves 120 cost-efficient and reliable.
[0062] In an embodiment, the thin fuel pipe 118 may be configured between a fuel tank 126 and the fuel injector assembly 106. The fuel from the fuel tank 126 may be allowed to flow through the thin fuel pipe 118 to the fuel injector assembly 106. The thin fuel pipe 118 may be a circular tube with a predefined diameter and length. The material used in the thin fuel pipe 118 may be stainless steel or special steel based on compatibility with the fuel used in the assembly 100. The predefined diameter and length of the thin fuel pipe 118 may be used as critical parameters, and may be configured such that the thin fuel pipe 118 may arrest the backflow of the plumes 104 into the low-inertia non-return valve 120. The diameter and the length of the thin fuel pipe 118 may further be optimized to allow the flow of the fuel from the low-inertia non-return valve 120 to the housing 102 as quickly as possible. The thin fuel pipe 118 may protect the temperature-sensitive components such as rubber sealants of the low-inertia non-return valve 120 from high-temperature due to combustion operations within the pre-combustion chamber of the housing 102.
[0063] In an embodiment, the assembly 100 may include a fuel pressure regulator 122. The fuel pressure regulator 122 may be operationally coupled between the fuel injector assembly 106 and the fuel tank 126. The fuel pressure regulator 122 may be configured on the thin fuel pipe 118 between the fuel injector assembly 106 and the fuel tank 126. The fuel pressure regulator 122 may regulate the pressure of the fuel flowing out of the thin fuel pipe 118 to the fuel injector assembly 106 from the fuel tank 126.
[0064] In an embodiment, the assembly 100 may include a fuel pressuring unit 124. The fuel pressuring unit 124 may be operatively coupled to the fuel tank 126. The fuel pressuring unit 124 may be configured on the thin fuel pipe 118 between the fuel tank 126 and the low-inertia non-return valve 120. The fuel pressuring unit 124 may pressurize liquid fuel leaving the fuel tank 126 and entering the low-inertia non-return valve 120. In case of gaseous fuel, the pressure of the gaseous fuel leaving the fuel tank 126 may be sufficient such that the assembly 100 may be functional without the need of the fuel pressuring unit 124.
[0065] In an embodiment, the fuel tank 126 may be in fluidic communication with the thin fuel pipe 118. The fuel tank 126 may be configured to store the fuel. In an exemplary embodiment, the fuel tank 126 may be, for example, but not limited to, a high pressure tank for storing the gaseous fuel.
[0066] In an embodiment, the assembly 100 may include a wire harness 128. The wire harness 128 may be in electrical communication with the assembly 100. The wire harness 128 may be configured among the ECU 202, a battery, the fuel injector assembly 106, the spark plug 108, the fuel pressure regulator 122, and the fuel pressuring unit 124. The wire harness 128 may be configured to transmit signals from the ECU 202 to the spark plug 108 and the fuel injector assembly 106.
[0067] In an embodiment, the second end 102B of the housing 102 may be configured within the combustion chamber of the cylinder 200 of the IC engine. The second air-fuel mixture may be ignited using the jet of plumes 106 emanating from the orifices 110 of the pre-combustion chamber of the housing 102. The size, number, and orientation of the orifices 110 may be optimized to provide a maximum coverage of the combustion chamber by the plumes 104 entering the combustion chamber of the cylinder 200.
[0068] Referring to FIG. 3, the sectional view of the assembly 100 is described. The fuel injector assembly 106 may inject a metered quantity of fuel into the pre-combustion chamber of the housing 102 for forming the lean first air-fuel mixture. Thereafter, the fuel may enter the pre-combustion chamber through the low-inertia non-return valve 120, as shown in FIG. 3. The low-inertia non-return valve 120 may use a rubber sealant and may include smaller moving parts which make the low-inertia non-return valve 120 more responsive. The low-inertia non-return valve 120 may shut the flow of the fuel between the fuel injector assembly 106 and the housing 102, thereby preventing the backflow of the combustion gases into the fuel injector assembly 106 upon the delivery of the fuel into the pre-combustion chamber. The thin fuel pipe 118 of the assembly 100 may be formed of a small diameter and a short length. The thin fuel pipe 118 may be connected between the low-inertia non-return valve 120 and the pre-combustion chamber 102. The thin fuel pipe 118 may arrest the hot plasma and dissipate heat returning from the hot plasma generated within the pre-combustion chamber 102 to the thin fuel pipe 118. The above process of arresting plasma may be similar to those used in flash-back arresters. The diameter of the thin fuel pipe 118 may be decided based on the type of the fuel used. The type of fuel may be liquid fuel or gaseous fuel. The diameter of the thin fuel pipe 118 may be small for the faster fuel flow. In an exemplary embodiment, there may be multiple fuel pipes 118 used instead of one fuel pipe. Moreover, the low-inertia non-return valve 120 may include elastomer sealants. Further, the moving parts of the low-inertia non-return valve 120 may be optimized to keep an inertia of the moving parts as low as possible.
[0069] The proposed assembly 100 may be experimentally tested for ignition and combustion where a sample housing 102 bearing a size of 1 cc approx. has been fabricated and experimentally tested. The sample housing 102 without connection to a fuel supply line which may be a simplified version of the final version may be considered for the experimental analysis as shown in FIG. 4 and FIG. 5. The sample housing 102 without connection to the fuel supply line may be sufficient to prove the concept as an igniter and verify the presence of turbulent plumes 104. The above experiment may be performed in a constant-volume combustion chamber (CVCC) with optical access. The schematic representations depicting a sequence of images at different timings starting from a time of spark, and a graphical representation depicting a comparison between pressure rise in the CVCC and the time are illustrated in FIG. 4 and FIG. 5, respectively. The experiment may be performed by filling the CVCC with, for example, a combustible mixture (lambda = 1) of methane and air to an initial pressure of around 7 bar. As the air-fuel mixture fills the CVCC, it may enter the small chamber through the orifices 110 connecting the sample housing 102 and the CVCC.
[0070] Further, the air-fuel mixture may be ignited by the one or more electrical pulses generated by the spark plug 108 mounted on the sample housing 102. High-speed shadowgraph images of the jet of plumes 104 exiting through the orifices 110 of the sample housing 102 into the CVCC may be observed. These jets igniting the air-fuel mixture in the CVCC have been recorded. The sequence of images at different times starting from the time of spark is depicted in FIG. 4. A comparison of pressure rise in the CVCC with time is depicted in Fig. 5 which demonstrates a faster rate of pressure rise with the fire-jet igniter. The fundamental experimental data may show the working of the sample housing 102 in terms of generation of turbulent jet of plumes 104 and achieving faster combustion rate when compared to the conventional ignition.
[0071] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper”, “top”, “bottom” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the FIGs. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the FIGs. For example, if the device in the figures is turned over, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” may encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
[0072] Herein, the terms “attached”, “connected”, “interconnected”, “contacting”, “mounted”, “coupled” and the like may mean either direct or indirect attachment or contact between elements, unless stated otherwise.
[0073] Well-known functions or constructions may not be described in detail for brevity and/or clarity. As used herein the expression “and/or” includes any and all combinations of one or more of the associated listed items.
[0074] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. 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 in this specification, specify the presence of stated features, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, operations, elements, components, and/or groups thereof.
[0075] While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications may be made, and that many changes may be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0076] The present disclosure overcomes the problems associated with existing spark plug for internal combustion (IC) engines, by providing a simple, compact, cost-effective, and efficient igniter assembly for an internal combustion (IC) engine.
[0077] The present disclosure provides a pre-combustion chamber having a volume of 5 to 30 percent of the volume of the IC engine’s combustion chamber.
[0078] The present disclosure provides an assembly that generates plume of heated air-fuel mixture for ignition of fuel within the IC engine’s cylinder.
[0079] The present disclosure provides an assembly that generates one or more electrical pulses between a nanosecond to microsecond.
The present disclosure provides an assembly which prevent backflow of fuel from the injector into the fuel injector assembly.

REFERENCE NUMERALS
PARTICULARS REFERRAL NUMERAL
Igniter assembly 100
Housing 102
First end 102A
Second end 102B
Cylinder of an IC engine 200
Electronic Control Unit (ECU) 202
Plumes 104
Fuel Injector Assembly 106
Spark Plug 108
Orifices 110
Ceramic Insert 112-1
Double Walled 112-2
First Port of the housing 114
Second Port of the housing 116
Thin Fuel Pipe 118
Low-inertia Non-return Valve 120
Fuel Pressure Regulator 122
Fuel Pressuring Unit 124
Fuel tank 126
Wire Harness 128

,CLAIMS:1. An igniter assembly (100) with a pre-combustion chamber for an internal combustion (IC) engine, wherein the assembly (100) is configured on a cylinder (200) of the IC engine, wherein the assembly (100) comprises:
a housing (102) having a pre-combustion chamber, wherein the housing (102) is in a fluidic communication with a low-pressure fuel injector assembly (106) through a thin fuel pipe (118);
a low-inertia non-return valve (120) configured on the thin fuel pipe (118) to inject fuel, at a low pressure, into the pre-combustion chamber while preventing backflow of the fuel into the fuel injector assembly (106); and
a spark plug (108) configured on the housing (102), such that:
the fuel received into the pre-combustion chamber mixes with air that is received into the pre-combustion chamber to form a first air-fuel mixture therein, which upon ignition by the spark plug (108), during a compression stroke of the IC engine, generates hot burnt gases or flames in the pre-combustion chamber,
wherein due to pressure generated within the pre-combustion chamber during combustion forces the generated hot burnt gases or flames through one or more orifices (110) of the housing (102) to form one or more combustion plumes (104) that enters a main combustion chamber of the cylinder (200), thereby igniting a pre-stored second air-fuel mixture therewithin.
2. The assembly (100) as claimed in claim 1, wherein the housing (102) having a first end (102A) and a second end (102B) is configured on at least one port on the cylinder (200) of the IC engine from the second end (102B).
3. The assembly (100) as claimed in claim 2, wherein the housing (102) comprises a first port (114), wherein the first port (114) is configured on the first end (102A) of the housing (102) to facilitate mounting of the spark plug (108).
4. The assembly (100) as claimed in claim 2, wherein the housing (102) comprises a second port (116), wherein the second port (116) is configured on the housing (102) between the first end (102A) and the second end (102B) to receive the fuel into the pre-combustion chamber from the fuel injector assembly (106).
5. The assembly (100) as claimed in claim 1, wherein the fuel injector assembly (106) is configured on the housing (102) between the first end (102A) and the second end (102B) for establishing a fluidic communication with the housing (102).
6. The assembly (100) as claimed in claim 1, wherein the spark plug (108) is configured on the housing (102) for generating one or more electrical pluses.
7. The assembly (100) as claimed in claim 1, wherein the one or more orifices (110) are configured on a second end (102B) of the housing (102) to generate the one or more plumes (104) when plasma generated upon igniting the first air-fuel mixture is forced through the one or more orifices (110) into the cylinder (200).
8. The assembly (100) as claimed in claim 7, wherein the one or more orifices (110) are formed of a predefined diameter, wherein the predefined diameter is selected between a range of 1 mm to 2 mm.
9. The assembly (100) as claimed in claim 1, wherein the assembly (100) comprises a thermally insulating component configured on inner walls at the second end (102B) of the housing (102) for thermal insulation of the housing (102), wherein the thermal insulating component is a ceramic insert (112-1) or a double walled portion (112-2).
10. The assembly (100) as claimed in claim 1, wherein a volume of the pre-combustion chamber is selected between a range of 5 percent to 30 percent of a volume of a combustion chamber of the cylinder (200).
11. The assembly (100) as claimed in claim 1, wherein the assembly (100) comprises an electronic control unit (ECU) (202) associated with the IC engine, wherein the ECU (202) is adapted to actuate the spark plug (108) for generating one or more electrical pulses within a predefined time period, and wherein the predefined time period is selected between a range of one nanosecond to one microsecond.
12. The assembly (100) as claimed in claim 11, wherein the ECU (202) is arranged in communication with the fuel injector assembly (106) to actuate the fuel injector assembly (106) for injecting the fuel into the pre-combustion chamber at a predefined pressure, wherein the predefined pressure is selected between a range of 3 bar to 10 bar.
13. The assembly (100) as claimed in claim 1, wherein the thin fuel pipe (118) is configured on a second port (116) of the housing (102).