Fuel supply to the pre-combustion chamber by spray from the fuel injector nozzle

Abstract

The engine includes an engine block (102) having a cylinder (101), a piston (105) movably disposed within a main chamber (103) of the cylinder (101), an auxiliary chamber (117) adjacent to and in fluid communication with the main chamber (103) via an auxiliary chamber nozzle (202), and a fuel injector (107) in fluid communication with the main chamber (103), the fuel injector having a spray nozzle (302) interfacing with the main chamber (103). The fuel injector (107) and the auxiliary chamber (117) are aligned such that a first one of the spray nozzles (302) is aimed at the auxiliary chamber nozzle (202).

Description

[Background technology]

[0001] Internal combustion engines generally may operate by combusting a fuel mixture in a combustion chamber, which may move one or more components within the engine. A typical internal combustion engine may include multiple cylinders defining combustion chambers within an engine block, with combustion within the cylinders moving internal pistons, which may in turn move the engine's crankshaft. The fuel mixture may be introduced into the combustion chamber through an inlet and combusted.

[0002] Combustion within an internal combustion engine's combustion chamber can occur using a variety of mechanisms, including high pressure and temperature conditions or the use of an ignition device. A typical ignition device configuration requires a continuous ignition source, or spark, to spark the air-fuel mixture within the engine's combustion chamber, resulting in combustion. Traditionally, a spark is generated by energizing a copper ignition rod and positioning the energized ignition rod within a predetermined distance from a grounded nickel or iridium plate, where the electrical difference between the energized ignition rod and the grounded plate generates a continuous spark. Alternatively, a portion of the air-fuel mixture may be ignited in a secondary combustion chamber, where the air-fuel mixture is ignited, and the resulting combustion reaction is released into the main combustion chamber, igniting the remainder of the air-fuel mixture. After combustion within the combustion chamber, combustion products may be discharged as exhaust from an outlet of the combustion chamber. Summary of the Invention [Means for solving the problem]

[0003] This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0004] In one aspect, embodiments disclosed herein relate to an engine including an engine block having a cylinder, a piston movably disposed within a main chamber of the cylinder, an auxiliary chamber adjacent to and in fluid communication with the main chamber via a nozzle, and a fuel injector in fluid communication with the main chamber, the fuel injector having a spray nozzle interfacing with the main chamber, the fuel injector and the auxiliary chamber being aligned such that a first nozzle of the spray nozzles is aimed at the nozzle of the auxiliary chamber.

[0005] In another aspect, embodiments disclosed herein relate to a pre-chamber injection method that includes providing an engine having an engine block having at least one cylinder, a piston movably disposed within a main chamber of the cylinder, an pre-chamber adjacent to and in fluid communication with the main chamber through a pre-chamber nozzle, and a fuel injector having a spray nozzle interfacing with the main chamber of the cylinder. The method may also include spraying fuel from a first one of the spray nozzles in a first direction toward the pre-chamber nozzle such that a first amount of fuel enters the pre-chamber nozzle. While spraying fuel from the first nozzle, fuel may be sprayed from a second one of the spray nozzles into the main chamber in a second direction different from the first direction.

[0006] Other aspects and advantages of the claimed subject matter will become apparent from the following description and appended claims.

[0007] Specific embodiments of the disclosed technology will now be described in detail with reference to the accompanying figures. Like elements in various figures are designated with like reference numerals for consistency. The sizes and relative positions of elements in the figures are not necessarily drawn to scale. For example, the shapes and angles of various elements are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve the readability of the figures. Furthermore, the particular shapes of the elements as drawn are not necessarily intended to convey any information regarding the actual shape of the particular elements, but have been selected merely for ease of recognition in the figures. [Brief explanation of the drawings]

[0008] [Figure 1] 1 illustrates a combustion system according to one or more embodiments.

[0009] [Figure 2] 1 illustrates a combustion system according to one or more embodiments.

[0010] [Figure 3A] 1 illustrates the alignment of the pre-chamber with the fuel injection according to one or more embodiments. [Figure 3B] 1 illustrates the alignment of the pre-chamber with the fuel injection according to one or more embodiments.

[0011] [Figure 4] 1 illustrates an engine timing chart according to one or more embodiments.

[0012] [Figure 5] 1 illustrates an engine timing chart according to one or more embodiments.

[0013] [Figure 6] 1 illustrates an engine timing chart according to one or more embodiments.

[0014] [Figure 7] 1 illustrates a computer system according to one or more embodiments.

[0015] [Figure 8] 1 illustrates a flowchart of a method according to one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the following detailed description of embodiments of the present disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0017] Throughout this application, ordinal numbers (e.g., first, second, third, etc.) may be used as adjectives for elements (i.e., any noun in this application). The use of ordinal numbers does not imply or create a particular order of elements, nor does it limit an element to only a single element, unless expressly disclosed, such as by use of the terms "before," "after," "single," and other such terms. Rather, the use of ordinal numbers distinguishes each element. As an example, a first element may be distinct from a second element, and the first element may encompass multiple elements and follow (or precede) the second element in the order of elements.

[0018] In the following description of Figures 1-8, in various embodiments disclosed herein, components described with respect to one figure may be equivalent to one or more similarly named components described with respect to other figures. For brevity, the description of these components may not be repeated in each figure. Accordingly, any and all embodiments of the components in each figure are incorporated by reference and are assumed to be optionally present in all other figures having one or more similarly named components. Furthermore, according to various embodiments disclosed herein, the description of a component in one figure should be interpreted as an optional embodiment that may be implemented in addition to, in conjunction with, or instead of the embodiment described with respect to the corresponding similarly named component in the other figures.

[0019] In one aspect, embodiments disclosed herein relate to spray-induced stratification for passive pre-chamber fueling. In another aspect, embodiments disclosed herein relate to a pre-chamber attached to and in fluid communication with a main chamber, where a fuel injector connected to the main chamber has one or more spray nozzles aligned with the pre-chamber nozzles. In yet another aspect, embodiments disclosed herein relate to a method of passively fueling a pre-chamber by aligning a fuel injector fuel spray with the pre-chamber nozzles.

[0020] Referring to FIG. 1, a combustion system 100 according to embodiments disclosed herein is shown. The combustion system 100 may be an internal combustion engine including at least one cylinder 101 formed within an engine body or engine block 102. While FIG. 1 illustrates only a portion of the engine block and only one cylinder within the engine block, the engine block may have several cylinders. The cylinder 101 may have an engine bore 315 defined between each sidewall of the cylinder (which may or may not include an engine liner). A main chamber 103 formed within the cylinder 101 may be the combustion chamber of the combustion system 100. Additionally, a cylinder head 104 may be attached to the top of the cylinder 101 and form an upper end of the main chamber 103. In one or more embodiments, the cylinder head 104 may have a pent roof angle 121 between 90 and 150 degrees. However, other embodiments may exist in which the cylinder head 104 may have a different geometry. A piston 105 may be disposed within the cylinder 101 and form a lower end of the main chamber 103. A piston 105 moves up and down inside the cylinder 101 during an engine cycle, and the position of the piston 105 changes the volume of the main chamber 103. Additionally, the piston 105 may be connected to a crankshaft (not shown) by a connecting rod. The crankshaft may convert the reciprocating motion of the piston 105 into rotational motion, as is known in the art.

[0021] An auxiliary chamber 117 may be disposed in fluid communication with the main chamber 103. The auxiliary chamber 117, according to one or more embodiments, may have a much smaller volume than the main chamber 103. For example, in one or more embodiments, the auxiliary chamber 117 may have a volume equal to 1% to 10% of the engine clearance volume, which may refer to the volume between the cylinder head 104 and the piston 105 when the piston 105 is at top dead center. In one or more embodiments, the exterior geometry of the auxiliary chamber 117 that interfaces with the main chamber 103 may be flat, concave, or convex, all of which may affect the flow characteristics and volume of the fuel spray that may enter the auxiliary chamber 117 under a given combustion strategy.

[0022] The pre-chamber 117 may have one or more nozzles integrally formed through an exterior wall of the pre-chamber 117, the one or more nozzles providing fluid communication between the pre-chamber 117 and the main chamber 103. In some embodiments, the nozzles may be holes having a selected shape formed through the pre-chamber wall. In some embodiments, the nozzles may be separate nozzle inserts inserted into holes formed through the pre-chamber wall. In one or more embodiments, the pre-chamber 117 may have between 1 and 12 nozzles. The one or more nozzles are configured to accelerate the fuel as it passes from the main chamber 103 to the pre-chamber 117, thereby improving fuel vaporization and mixing. A spark plug 118 may be connected to the pre-chamber 117 and configured to interface with the pre-chamber 117. For example, the spark plug 118 may be located in the cylinder head 104 to interface with the end of the pre-chamber 117 opposite the main chamber 103. A spark plug 118 may be used to ignite fuel in the pre-chamber 117, which may then be ejected through one or more nozzles into the main chamber 103.

[0023] A fuel injector 107 according to an embodiment of the present disclosure may be mounted within the cylinder head 104. A clamp (not shown) may removably secure the fuel injector 107 to the cylinder head 104. The clamp may be disposed on top of the fuel injector 107 and attached to the cylinder head 104 to hold the position of the fuel injector 107. The fuel injector 107 may be aligned, coaxial, or angled relative to the cylinder axis of the cylinder head 104. In one example, installing the fuel injector 107 in the cylinder head 104 includes providing one or more atomizing nozzle assemblies at the tip of the fuel injector. In some embodiments, the nozzle assemblies may include fuel channels, premixer tubes, and ports formed within the tip of the fuel injector 107. The fuel injector 107 may be in fluid communication with the main chamber 103, in which case one or more atomizing nozzle assemblies may be positioned such that the orifices of the atomizing nozzle assemblies are in fluid communication with the main chamber 103.

[0024] In one or more embodiments, the one or more spray nozzle assemblies may have a wide spray angle. A first of the one or more spray nozzle assemblies may be aimed at and aligned with one of the nozzles in the pre-chamber 117. This first spray nozzle assembly may be configured to passively fuel the pre-chamber 117 while actively fueling the main chamber 103.

[0025] Continuing with reference to FIG. 1 , the cylinder head 104 may optionally include a second fuel injector 108 used in combination with the fuel injector 107. As shown, the cylinder head 104 may include at least one intake passage 119 terminating in a second intake port 110. The second fuel injector 108 may be disposed along the intake passage 119 in a configuration that enables injection of fuel into the intake passage 119. The second fuel injector 108 may be a fuel injector similar to the fuel injector 107. Further, the intake port 110 may include an intake valve 113 for controlling the opening and closing of the intake port 110. Air flowing through the intake passage 119 into the main chamber 103 may be entrained in the fuel spray plume of the second fuel injector 108 when the second fuel injector 108 is injecting fuel. Although not shown, the main chamber 103 and the intake passage 119 may be connected to an air source in a conventional manner. The air in the main chamber 103 and intake passage 119 may be ambient air or a mixture of ambient air and recirculated exhaust gases.

[0026] The cylinder head 104 may also include at least one exhaust passage 111 having an exhaust port 112. An exhaust valve 114 may be positioned to control the opening and closing of the exhaust port 112. When the exhaust port 112 is open, exhaust gases may be forced from the main chamber 103 into the exhaust passage 111. An intake passage 119, exhaust passage 111, and associated components (e.g., valves 113, 114, and fuel injectors 107, 108) may be provided in the cylinder head 104 for each cylinder in the combustion system 100, for example, in the arrangement shown in FIG. 1 for cylinder 101.

[0027] In one or more embodiments, the fuel injectors 107, 108 may be used to inject fuel directly into the main chamber 103 and / or the intake passage 119. The fuel injectors 107, 108 may be fluidly connected to a fuel line 115 that is in communication with a fuel supply 116.

[0028] In one or more embodiments, the computer 120 may include a control system, such as an engine control unit, that may control the opening and closing of the fuel injectors 107, 108 to deliver fuel into the main chamber 103 at desired times during the engine cycle. The control system may also control the opening and closing of the intake and exhaust valves 113, 114. In one or more embodiments, the computer 120 may include a user interface panel and a processor that allows a user to provide input, such as commands, to the computer 120.

[0029] In some embodiments, cables (not shown), such as electrical or hydraulic power cables, may be coupled to the fuel injectors 107, 108. The cables may provide power to the fuel injectors 107, 108 from a power source (not shown). Additionally, the cables may be connected to a computer 120 to control the fuel injectors 107, 108. The computer 120 may contain instructions or commands to automatically operate the fuel injectors 107, 108, or a user may manually control the computer 120 at a user interface panel (not shown). It is further envisioned that the computer 120 may be connected to an office via satellite to allow a user to remotely monitor the status and send commands to the fuel injectors 107, 108. If leaks or performance issues are found, an alert may be sent to a control system to manually or automatically adjust or turn off the fuel injectors 107, 108.

[0030] In one or more embodiments, the combustion system 100 may be used to perform turbulent jet-controlled compression ignition (TJCCI). TJCCI may include passively fueling the pre-chamber 117 and igniting the fuel within the pre-chamber 117. The ignited fuel may then be ejected from the pre-chamber 117 into the main chamber 103 through one or more of a plurality of nozzles.

[0031] Referring now to Figure 2, Figure 2 illustrates a combustion system according to one or more embodiments. As described in Figure 1, the pre-chamber 117 may have multiple nozzles 202 that allow fuel to enter and exit the pre-chamber 117. The multiple nozzles 202, according to one or more embodiments, allow for acceleration and vaporization of the fuel as it enters the pre-chamber 117 from the main chamber 103. This may allow for improved mixing within the pre-chamber 117.

[0032] In one or more embodiments, the fuel injector 107 may have one or more spray nozzles through which one or more fuel sprays 204 may be injected. A first one of the fuel sprays 204 may be directed toward one of the nozzles 202 so that a volume of fuel may enter the pre-chamber 117. Another one of the fuel sprays 204 may be directed toward the main chamber 103. In one or more embodiments, the direction of the first fuel spray 204 may be different from the direction of the other fuel sprays 204.

[0033] 3A-3B, which illustrate the alignment of a pre-chamber nozzle with a fuel injector spray nozzle according to one or more embodiments. Figure 3A illustrates a top view of the inner surface of the cylinder head 104 with the pre-chamber 117 and fuel injector 107 protruding from the inner surface of the cylinder head 104 and positioned between the intake and exhaust valves. Figure 3B illustrates a cross-sectional view of the engine assembly shown in Figure 3A along section AA of Figure 3A.

[0034] The fuel injector 107 may have one or more atomizing nozzles 302 through which fuel can be distributed, and the pre-chamber 117 may have one or more nozzles 202 through which atomized fuel can be received from the fuel injector 107. Depending on the engine size, the fuel injector 107 and the pre-chamber 117 may be spaced apart such that a first fuel injector nozzle 302a and a first pre-chamber nozzle 202a aligned with the first fuel injector nozzle 302a are separated by a distance in the range of approximately 1% to 20% of the engine bore 315 (shown in FIG. 1 ).

[0035] Each of the fuel injector spray nozzles 302 may have a different nozzle size and spray angle (also referred to as a cone angle). In contrast to commercially available spray nozzles, the spray nozzles 302 disclosed herein may provide a wider cone angle to properly target one of the nozzles 202 in the pre-chamber 117. The cone angle may be measured as an angle across the outer diameter of the fuel spray 204 exiting the spray nozzle 302. Thus, as best shown in FIG. 3B , a half cone angle 312 may be measured between the outer diameter of the spray plume from the fuel injector 107 and a central axis 314 of the fuel injector 107. According to embodiments of the present disclosure, at least one nozzle 302 of the fuel injector 107 may be oriented to align with at least one pre-chamber nozzle 202, as represented by spray alignment path 313 in FIG. 3B , thereby providing a wider cone angle when compared to the fuel spray of a conventional fuel injector. 3B, a first fuel injector nozzle 302a may be aligned with and oriented to face the first sub-chamber nozzle 202a so that fuel sprayed from the first fuel injector nozzle 302a can flow along a spray alignment path 313 and enter the first sub-chamber nozzle 202a. The half spray angle 312 provided by the first fuel injector nozzle 302a may be greater than the half spray angles provided by the remaining fuel injector nozzles 302 so that the total spray angle from the fuel injector 107 can be greater than that provided by a conventional fuel injector.

[0036] Conventional center- or top-mounted fuel injectors for gasoline engines may have a spray angle in the range of 30 to 90 degrees to avoid fuel spray onto the engine liner and associated oil dilution. Meanwhile, one or more nozzles 302 of a fuel injector 107 according to embodiments disclosed herein may be oriented to provide the same spray angle as a conventional fuel injector, but at least one fuel injector nozzle 302a aligned with a pre-chamber nozzle 202a may provide a larger spray angle. For example, according to embodiments of the present disclosure, a first fuel injector nozzle 302a aligned with a first pre-chamber nozzle 202a may provide a spray angle in the range of approximately 100 to 130 degrees. According to embodiments of the present disclosure, the wider spray from such a nozzle configuration may be limited to a shorter duration than traditionally used, thereby avoiding fuel spray reaching the engine liner and associated oil dilution. Furthermore, performing dual injection events per cylinder cycle may also enable the use of shorter spray durations while providing the same or similar total fuel injection volume per cycle.

[0037] In one or more embodiments, each of the multiple nozzles 202 may be designed to appropriately accelerate and vaporize the fuel from the first fuel spray 204. The pre-chamber nozzle 202 may be formed as an opening in the pre-chamber wall or may be a separate nozzle insert inserted through the pre-chamber wall. In some embodiments, to increase the likelihood of the mixture entering the pre-chamber, the nozzle may have a lip or ridge formed around the nozzle outer orifice to capture the spray plume from the fuel injector. Additionally, the pre-chamber nozzle 202 may have a small diameter, such as in the range of approximately 0.9 to 1.1 mm, designed to increase the velocity and turbulence level of the mixture driven through the nozzle 202 by the pressure difference between the main chamber and the pre-chamber due to piston compression. This increased velocity and turbulence level of the mixture through the nozzle 202 can improve fuel vaporization.

[0038] As mentioned above, in one or more embodiments, the first pre-chamber nozzle 202a and the first fuel injector spray nozzle 302a may be aligned such that fuel dispensed from the first spray nozzle 302a can enter the pre-chamber 117 through the first pre-chamber nozzle 202a. To provide such nozzle alignment, according to embodiments of the present disclosure, the hardware of the fuel injector 107 and pre-chamber 117 may be provided with stops and / or restraints that fit into and / or mate with corresponding receptacles in the engine head to hold the fuel injector nozzle and pre-chamber nozzle aligned when the fuel injector and pre-chamber are installed in the engine.

[0039] Referring now to FIG. 4, FIG. 4 illustrates an engine timing diagram 400 for a single direct injection combustion strategy according to one or more embodiments. An engine timing diagram, such as engine timing diagram 400, may represent the four strokes of an engine (exhaust, intake, compression, and expansion) as well as the timing of each of the exhaust and intake valve actuations, fuel injection timing, and spark timing. Referring back to FIG. 1, in one or more embodiments, each engine cycle may correspond to two revolutions (four strokes) of the piston 105 within the cylinder 101. Thus, there may be two instances where the piston 105 can reach a top dead center position: gas exchange top dead center 402, located between the exhaust stroke 404 and the intake stroke 406, and ignition top dead center 408, located between the compression stroke 410 and the expansion stroke 412.

[0040] 1 and 4, a single direct injection combustion strategy may include fuel injection 414 via fuel injector 107 late in the compression stroke 410. A spark 416 may be generated by spark plug 118 immediately after fuel injection 414 and just before piston 105 reaches firing top dead center position 408.

[0041] 5, which illustrates an engine timing diagram 500 for a multiple direct injection combustion strategy according to one or more embodiments. Referring to FIGS. 1 and 5, the multiple direct injection combustion strategy may include multiple fuel injections 502 by a fuel injector 107 on both the intake stroke 406 and the compression stroke 410. A spark 416 may be generated by a spark plug 118 just prior to top dead center 408.

[0042] Referring now to Figure 6, Figure 6 shows an engine timing diagram 600 for a port fuel injection and direct injection combustion strategy according to one or more embodiments. Referring to Figures 1 and 6, the port fuel injection and direct injection combustion strategy may include port fuel injection 602 via fuel injector 108 during intake stroke 406 and direct fuel injection 604 by fuel injector 107 during compression stroke 410. A spark 416 may be generated by spark plug 118 just prior to ignition top dead center 408.

[0043] In each of the combustion strategies described in Figures 4-6, the fuel injector 107 may have multiple spray nozzles 302 or a single spray nozzle 302, which may reduce fuel stratification in the main chamber 103 and reduce nitrogen oxide emissions. One or more spray nozzles 302 may be sized to match the hydraulic volume of fuel passing through the spray nozzle 302 with the required amount of stratified fuel. Additionally, each of the one or more spray nozzles 302 may have a spray behavior that matches the distance between the spray nozzle 302 and the nozzle 202 in the pre-chamber 117 to avoid liquid impingement while maintaining vapor impingement. One or more spray nozzles 302 may have a wide angle, such as angle 121 shown in Figure 1, to allow proper alignment with the nozzle 202 in the pre-chamber 117.

[0044] 7 illustrates a block diagram of a computer system 702 that may be used to provide the computational functionality associated with the described algorithms, methods, functions, processes, flows, and procedures as described in this disclosure, according to one or more embodiments. The illustrated computer 702 is intended to encompass any computing device, such as a server, desktop computer, laptop / notebook computer, wireless data port, smartphone, personal digital assistant (PDA), tablet computing device, one or more processors within these devices, or other suitable processing device (including both physical and virtual instances of a computing device). Additionally, computer 702 may include a computer that includes input devices, such as a keypad, keyboard, touchscreen, or other device capable of receiving user information, and output devices that communicate information related to the operation of computer 702, including digital data, visual or audio information (or a combination of information), or a GUI.

[0045] The computer 702 may act as a client, a network component, a server, a database or other persistence, or any other component of a computer system for implementing the subject matter described in this disclosure (or a combination of roles). The illustrated computer 702 is communicatively coupled to a network 730. In some implementations, one or more components of the computer 702 may be configured to operate within an environment, including a cloud computing-based, local, global, or other environment (or combination of environments).

[0046] Generally speaking, computer 702 is an electronic computing device operable to receive, transmit, process, store, or manage data and information related to the described subject matter. According to some implementations, computer 702 may also include or be communicatively coupled to an application server, email server, web server, caching server, streaming data server, business intelligence (BI) server, or other server (or combination of servers).

[0047] Computer 702 can receive requests over network 730 from client applications (e.g., running on another computer 702) and respond to the received requests by processing the requests with an appropriate software application. In addition, requests may also be sent to computer 702 from internal users (e.g., from a command console or by other suitable access methods), external or third parties, other automated applications, and any other suitable entity, individual, system, or computer.

[0048] The components of the computer 702 can communicate using a system bus 703. In some implementations, any or all of the components (either hardware or software (or a combination of hardware and software)) of the computer 702 may interface with each other or with the interface 704 (or a combination of both) via the system bus 703 using an application programming interface (API) 712 or a service layer 713 (or a combination of the API 712 and the service layer 713). The API 712 may include specifications of routines, data structures, and object classes. The API 712 may be computer language independent or language dependent and may refer to a complete interface, a single function, or even a set of APIs. The service layer 713 provides software services to the computer 702 or other components (whether shown or not) communicatively coupled to the computer 702. The functionality of the computer 702 may be accessible to all service consumers using this service layer. Software services, such as those provided by the service layer 713, provide reusable, defined business functions through defined interfaces. For example, the interface may be software written in JAVA, C++, or another suitable language that provides data in Extensible Markup Language (XML) format or another suitable format. Although shown as an integrated component of computer 702, alternative implementations may depict API 712 or services layer 713 as standalone components associated with other components of computer 702 or other components (whether shown or not) communicatively coupled to computer 702. Furthermore, any or all portions of API 712 or services layer 713 may be implemented as a child module or sub-module of another software module, enterprise application, or hardware module without departing from the scope of the present disclosure.

[0049] Computer 702 includes an interface 704. While a single interface 704 is shown in FIG. 7, more than one interface 704 may be used according to the particular needs, desires, or particular implementation of computer 702. Interface 704 is used by computer 702 to communicate with other systems in a distributed environment connected to network 730. Generally, interface 704 includes logic encoded in software or hardware (or a combination of software and hardware) operable to communicate with network 730. More specifically, interface 704 may include software supporting one or more communication protocols related to communication such that network 730 or interface hardware is operable to communicate physical signals within and outside of illustrated computer 702.

[0050] Computer 702 includes at least one computer processor 705. While shown in Figure 7 as a single computer processor 705, more than one processor may be used according to the particular needs, desires, or particular implementation of computer 702. Generally, computer processor 705 executes instructions and manipulates data to perform the operations of computer 702 and any machine learning networks, algorithms, methods, functions, processes, flows, and procedures as described in this disclosure.

[0051] The computer 702 also includes a memory 706 that holds data for the computer 702 or other components (or a combination of both), which may be connected to a network 730. For example, the memory 706 may be a database that stores data consistent with the present disclosure. While shown in FIG. 7 as a single memory 706, two or more memories may be used according to the particular needs, desires, or particular implementation of the computer 702 and the described functionality. While the memory 706 is shown as an integral component of the computer 702, in alternative implementations, the memory 706 may be external to the computer 702.

[0052] Application 707 is an algorithmic software engine that provides functionality according to the specific needs, desires, or specific implementation of computer 702, particularly with respect to the functionality described in this disclosure. For example, application 707 can function as one or more components, modules, applications, etc. Further, while shown as a single application 707, application 707 may be implemented as multiple applications 707 on computer 702. Additionally, while shown as integral to computer 702, in alternative implementations application 707 can be external to computer 702.

[0053] Any number of computers 702 may be associated with or external to the computer system that includes computer 702, with each computer 702 communicating via network 730. Furthermore, the terms "client," "user," and other appropriate terminology may be used interchangeably as appropriate without departing from the scope of this disclosure. Furthermore, this disclosure contemplates that many users may use one computer 702, or that one user may use multiple computers 702.

[0054] FIG. 8 illustrates a flowchart according to one or more embodiments. More specifically, FIG. 8 illustrates a flowchart 800 of a sub-chamber injection method. Furthermore, one or more of the blocks in FIG. 8 may be performed by one or more components such as those described in FIGS. 1-7. While the blocks in FIG. 8 are presented and described sequentially, one skilled in the art will understand that some or all of the blocks may be performed in a different order, combined, or omitted, and some or all of the blocks may be performed in parallel. Furthermore, the blocks may be performed actively or passively.

[0055] First, an engine may be provided (S802). In one or more embodiments, the engine may include an engine block 102 having a cylinder 101 and a piston 105 movably disposed within a main chamber 103 of the cylinder 101. The engine may also include an auxiliary chamber 117 adjacent to and in fluid communication with the main chamber 103 via a nozzle 202, and a fuel injector 107 in fluid communication with the main chamber 103. In one or more embodiments, the fuel injector 107 has a spray nozzle 302 that interfaces with the main chamber 103, such that a first nozzle of a spray nozzle 320 is directed toward the nozzle 202 of the auxiliary chamber.

[0056] Fuel may be sprayed in a first direction from a first one of the spray nozzles 302 toward the nozzle 202 of the auxiliary chamber 117 (S804). Fuel may also be sprayed in a second direction from a second one of the spray nozzles 202 into the main chamber 103 (S806). In one or more embodiments, the first direction may be different from the second direction. In one or more embodiments, a consistent flow direction from the main chamber 103 to the auxiliary chamber 117 may be created during the compression stroke 410 of the piston 105.

[0057] In one or more embodiments, the method described in flowchart 800 may also include controlling the equivalence ratio of the mixture in the main chamber 103 through injection timing and injection duration. Equivalence ratio may refer to the ratio of fuel to air in the main chamber 103. In one or more embodiments, the injection timing and injection duration may be determined at least in part based on the charge pressure in the main chamber. The injection timing and injection duration may be optimized for multiple desired engine speeds and multiple desired load conditions. Different fuel supply levels in the pre-chamber 117 may be provided via the fuel injector 107 depending on the injection timing and duration optimized for each desired speed and condition.

[0058] The method described in flowchart 800 may further include retaining fluid in the pre-chamber 117 and using pressure in the main chamber 103 during the compression stroke 410 of the piston 104 to prevent fuel leakage from the pre-chamber 117. Additionally, passively fueling the pre-chamber 117 may include increasing the velocity and turbulence of the fuel in the pre-chamber 117 (e.g., by injecting atomized fuel from the fuel injector 107 into the pre-chamber through the nozzle 202) to improve the mixing and combustion rate of the fuel in the pre-chamber 117, and then injecting the fuel from the pre-chamber 117 into the main chamber 103 to ignite the fuel in the main chamber 103.

[0059] In one or more embodiments, the pre-chamber injection method illustrated in flowchart 800 may be a single direct injection strategy that includes directing fuel from fuel injector 107 into pre-chamber 117 and main chamber 103 late in the compression stroke 410 of piston 105. A single direct injection strategy is characterized by fuel injection occurring only once during a four-stroke cylinder cycle. Additionally, a multiple direct injection strategy may be implemented in which fuel injection occurs multiple times during a four-stroke cylinder cycle. In one or more embodiments, the single direct injection strategy and multiple direct injection strategy may also include igniting fuel with spark plug 118 in pre-chamber 117.

[0060] Pre-chamber injection methods may also be implemented using port fuel injection and direct injection strategies. For example, port fuel injection (via fuel injector 108 along intake passage 119) may be implemented during the intake stroke 406 of piston 105, and direct injection of fuel into main chamber 103 and pre-chamber 117 may be implemented later in the compression stroke 410 of piston 105. Port fuel injection and directional injection strategies may also include igniting fuel with a spark plug 118 in pre-chamber 117.

[0061] Embodiments of the present disclosure may provide at least one of the following advantages: Passively fueling the pre-chamber can help increase fuel velocity and turbulence within the pre-chamber, thereby increasing fuel mixing. Improved fuel mixing also improves the burn rate of the fuel mixture within the pre-chamber, thereby increasing jet momentum into the main chamber. Creating a powerful turbulent jet stream from the pre-chamber into the main chamber results in repeatable main chamber combustion, even under ultra-lean dilution conditions. Furthermore, passively fueling the pre-chamber eliminates the need for direct fuel injectors within the pre-chamber, reducing engine costs. Furthermore, if fuel injectors were installed within the pre-chamber, the pre-chamber volume would necessarily be much larger, which can make it difficult to maintain desired engine dimensions, especially when a compact engine is required. Passively fueling the pre-chamber as described herein enables all of the benefits of actively fueling the pre-chamber (such as reduced nitrogen oxide emissions) while reducing costs and maintaining engine efficiency.

[0062] While only a few exemplary embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without substantially departing from the invention, and all such modifications are therefore intended to be included within the scope of the present disclosure as defined in the following claims.

Claims

1. an engine block having a cylinder; a piston movably disposed within the main chamber of the cylinder; an antechamber adjacent to and in fluid communication with the main chamber via a nozzle; a fuel injector in fluid communication with the main chamber; the fuel injector having a spray nozzle interfacing with the main chamber; the fuel injector and the sub-chamber are aligned such that a first one of the spray nozzles is directed toward the nozzle; engine.

2. The engine of claim 1 , wherein one or more of the spray nozzles are directed into the main chamber.

3. 3. The engine of claim 1, wherein the cylinder has a cylinder head with a pent roof angle of 5 to 25 degrees.

4. An engine according to any one of claims 1 to 3, wherein the fuel injector is configured to atomize fuel with an atomizing moment through the atomizing nozzle.

5. An engine according to any one of claims 1 to 4, further comprising a spark plug connected to and interfacing with said pre-chamber.

6. An engine according to any one of claims 1 to 5, wherein the pre-chamber further comprises at least one additional nozzle providing fluid communication between the pre-chamber and the main chamber.

7. An engine according to any one of claims 1 to 6, wherein the pre-chamber has a volume equal to 1% to 10% of the engine clearance volume.

8. An engine according to any one of claims 1 to 7, wherein the outer surface geometry of the pre-chamber may be selected from the group consisting of flat, concave and convex.

9. An engine as claimed in any one of claims 1 to 8, wherein the nozzle of the pre-chamber is separated from the spray nozzle by a distance in the range of 1 to 20 percent of the engine bore diameter.

10. an engine block having cylinders; a piston movably disposed within the main chamber of the cylinder; an antechamber adjacent to and in fluid communication with the main chamber via a nozzle; and a fuel injector having a spray nozzle interfacing with the main chamber of the cylinder; providing an engine comprising: spraying fuel from a first one of the spray nozzles in a first direction toward the nozzle of the sub-chamber such that a first amount of fuel enters the nozzle; spraying fuel from a second nozzle of the spray nozzles into the main chamber in a second direction different from the first direction while spraying fuel from the first nozzle; A pre-chamber injection method including:

11. and controlling the equivalence ratio of the mixture in the main chamber by injection timing and injection duration.

11. The method of claim 10, wherein the injection timing and the injection duration are determined at least in part based on charge pressure in the main chamber.

12. optimizing the injection timing and the injection duration for multiple engine speeds and multiple load conditions; providing different fuel supply levels into the pre-chamber based on the optimized injection timing and injection duration; The method of claim 11 further comprising:

13. 13. The method of claim 10, further comprising creating a consistent flow direction from the main chamber to the pre-chamber during the compression stroke of the piston.

14. 14. The method of claim 13, further comprising: retaining fluid in the pre-chamber; and using pressure in the main chamber from the compression stroke of the piston to prevent fuel leakage from the pre-chamber.

15. increasing the velocity and turbulence of the fuel within the pre-chamber to improve the mixing and combustion rate of the fuel within the pre-chamber; igniting the fuel with a spark plug in the pre-chamber; Injecting the fuel from the auxiliary chamber into the main chamber; The auxiliary chamber injection method according to any one of claims 10 to 14, further comprising:

16. 16. The method of any one of claims 10 to 15, further comprising sizing the spray nozzle to achieve a desired hydraulic flow rate.

17. utilizing a single direct injection strategy during a late compression stroke of the piston, the single direct injection strategy includes directing the fuel from the fuel injector into the pre-chamber and the main chamber only once during a four-stroke cylinder cycle; igniting the fuel with a spark plug in the pre-chamber; The auxiliary chamber injection method according to any one of claims 10 to 16, further comprising:

18. injecting fuel into the main chamber and the sub-chamber during an intake stroke of the piston; injecting fuel into the main chamber and the sub-chamber during a later compression stroke of the piston; igniting the fuel with a spark plug in the pre-chamber; The auxiliary chamber injection method according to any one of claims 10 to 17, further comprising:

19. performing port fuel injection during the intake stroke of the piston; performing direct injection of fuel into the main chamber and the pre-chamber during a later compression stroke of the piston; igniting the fuel with a spark plug in the pre-chamber; The auxiliary chamber injection method according to any one of claims 10 to 18, further comprising:

20. The method for pre-chamber injection according to any one of claims 10 to 19, further comprising atomizing fuel with an atomizing momentum through the spray nozzle.

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