The present application is a national stage application of International (PCT) Patent Application Serial No. PCT/US2015/054592, filed on Oct. 8, 2015, the complete disclosure of which is expressly incorporated by reference herein.
The present disclosure relates to a pre-chamber assembly of an internal combustion engine and, more particularly, to a pre-chamber assembly having a plurality of nozzles directed to one location in a piston bowl of a piston of the internal combustion engine.
An internal combustion engine may include both a main chamber and a pre-chamber or antechamber. The main chamber includes a piston configured to reciprocate during a combustion cycle. The pre-chamber is positioned above the main chamber and within the cylinder head of the engine. The pre-chamber may include a spark plug such that combustion may be initiated in the pre-chamber rather than the main chamber. Because there is lower turbulence of the air and/or fuel within the pre-chamber relative to the main chamber at the time of ignition, initiating combustion in the pre-chamber, rather than the main chamber, may allow for consistent initial flame kernel growth which may lead to more efficient combustion.
Various types of pre-chambers may be provided within the cylinder head, including a passive pre-chamber, a charge-fed pre-chamber, and a fuel-fed pre-chamber. A passive pre-chamber assembly does not directly receive any air and/or fuel, but rather, receives air and/or fuel from the main chamber during the compression stroke of the piston. A fuel-fed pre-chamber assembly receives raw fuel directly into the pre-chamber assembly during a combustion cycle. A charge-fed pre-chamber assembly receives a charge of air and fuel directly into the pre-chamber assembly during a combustion cycle. Any of the pre-chambers may be in the form a spray-nozzle pre-chamber, which include a plurality of nozzles each directed to a different location within the main chamber.
Spray nozzle-type pre-chambers may result in incomplete combustion because the outlet jets expelled from the pre-chamber during combustion may not mix thoroughly with the charge in the main chamber. More particularly, because the spray nozzle-type pre-chamber focuses a plurality of individual outlet jets at different locations within the main chamber, the outlet jets form a plurality of small ignition sites, rather than a single, large ignition site, which may contribute to poor ignition in the main chamber. Therefore, a need exists for a pre-chamber configured to increase ignition within the main chamber.
In one embodiment of the present disclosure, a pre-chamber assembly of an internal combustion engine comprises a pre-chamber housing and a plurality of nozzles extending through a portion of the pre-chamber housing. The plurality of nozzles are directed to one location.
In one aspect of the pre-chamber assembly, an output from each nozzle is configured to converge at the one location at a predetermined operation of the engine.
In a further aspect of the pre-chamber assembly, the predetermined operation of the engine is selected from the group consisting of a position of a piston within a combustion chamber of the engine, a position of a crankshaft of the engine, a pressure in the pre-chamber housing, and a pressure in a main chamber of the engine.
In another aspect of the pre-chamber assembly, the pre-chamber assembly is a passive pre-chamber assembly.
In another aspect of the pre-chamber assembly, the pre-chamber assembly is a fuel-fed pre-chamber assembly.
In another aspect of the pre-chamber assembly, the pre-chamber assembly is a charge-fed pre-chamber assembly.
In a further aspect of the pre-chamber assembly, the output from each nozzle converges toward a center portion of a combustion chamber of the internal combustion engine.
In another aspect of the pre-chamber assembly, each nozzle is configured to receive a flow of charge from the combustion chamber, and a velocity of the flow of charge is less than 110 msec.
In one aspect of the pre-chamber assembly, the velocity of the flow of charge is less than 90 msec.
In another aspect of the pre-chamber assembly, the pre-chamber housing has a first diameter and each nozzle has a second diameter, and the ratio of the first diameter to the second diameter is 3.0-6.0.
In one variant of the pre-chamber assembly, the ratio of the first diameter to the second diameter is 3.4-5.0.
In another embodiment of the present disclosure, an internal combustion engine comprises at least one cylinder including a main chamber and a pre-chamber fluidly coupled to the main chamber, a plurality of nozzles fluidly coupling the pre-chamber and the main chamber, and a piston positioned in the main chamber and including a piston bowl facing the pre-chamber. An output from each of the nozzles is configured to converge within the piston bowl.
In one aspect of the internal combustion engine, the output from each nozzle converges at a center portion of the piston bowl.
In a further aspect of the internal combustion engine, an ignition device is supported within the pre-chamber and configured to ignite a charge in the pre-chamber.
In one aspect of the internal combustion engine, the engine comprises at least one coolant flow path, and at least one of the pre-chamber and the ignition device is positioned within the coolant flow path.
In one aspect of the internal combustion engine, each nozzle is angled toward a center portion of the pre-chamber.
In one aspect of the internal combustion engine, the pre-chamber has a first diameter and each nozzle has a second diameter, and the ratio of the first diameter to the second diameter is 3.0-6.0.
In one aspect of the internal combustion engine, the ratio of the first diameter to the second diameter is 3.4-5.0.
In one aspect of the internal combustion engine, each nozzle has the same diameter.
In a further embodiment of the present disclosure, a method of initiating combustion within an internal combustion engine comprises providing a main chamber extending along a longitudinal axis, providing a pre-chamber fluidly coupled to the main chamber through a plurality of nozzles, igniting a charge in the pre-chamber, and focusing an output of the ignited charge from each nozzle toward one location within the main chamber.
In one aspect of the method, the method further comprises providing a piston with a piston bowl within the main chamber, wherein focusing the output includes focusing the output of the ignited charge from each nozzle toward a center portion of the piston bowl.
In one aspect of the method, focusing the output includes converging the output of the ignited charge from each nozzle within the piston bowl.
In one aspect of the method, the method further comprises further comprising flowing a second charge from the main chamber into the piston bowl, wherein focusing the output includes converging the output of the ignited charge from each nozzle within the piston bowl below the flow of the second charge.
Advantages and features of the embodiments of this disclosure will become more apparent from the following detailed description of exemplary embodiments when viewed in conjunction with the accompanying drawings.
Referring to
Each cylinder assembly 2 includes a cylinder 4 and a cylinder head 6. Cylinder head 6 is sealingly coupled to cylinder 4 with a gasket 16 (
As shown in
As shown in
Illustratively, pre-chamber assembly 20 is a passive pre-chamber which includes a first housing member 22, a second housing member 24, a first seal 26, a second seal 28, a third seal 30, and a fourth seal 31 (
Illustratively, first housing member 22 includes three nozzles 52 which may be spaced approximately 120° apart from each other. Each nozzle 52 may have a diameter d (
As shown in
As shown in
Second housing member 24 is sealingly received within channel 36 of cylinder head 6 with second seal 28. Additionally, second housing member 24 may be coupled to cylinder head 6 with retaining member 32 and coupler 34. Alternatively, retaining member 32 may be configured to retain another component of the internal combustion engine on cylinder head 6 (e.g., a fuel injector, spark plug, or any other component configured to be supported on or within cylinder head 6). Retaining member 32 includes a tab 44 with an opening 46 which aligns with an opening 48 in cylinder head 6 to receive a coupler 34. Retaining member 32 also includes a semi-circular receiving surface 50 for receiving a portion of second housing member 24 or another component of the internal combustion engine.
Second housing member 24 has a cylindrical channel 54. An ignition device, illustratively a spark plug 56, is positioned within channel 54 and extends into internal volume 72 of first housing member 22. As such, spark plug 56 extends between first and second housing members 22, 24. More particularly, spark plug 56 is sealingly coupled against an inner surface of first housing member 22 with fourth seal 31 but is spaced apart from an inner surface of second housing member 24. Spark plug 56 also may include threads for threadedly coupling with a threaded portion 64 of first housing member 22, as shown in
During operation of the internal combustion engine, fuel and/or air is supplied to cylinder bore 5 and/or pre-chamber assembly 20 for combustion. In one embodiment, fuel and air may be separately provided directly to cylinder bore 5 and/or pre-chamber assembly 20. Alternatively, fuel and air may be mixed to form a fuel/air mixture, or “charge”, when introduced into cylinder bore 5 and/or pre-chamber assembly 20.
In the illustrative embodiment of cylinder assembly 2, combustion is initiated in pre-chamber assembly 20, rather than in cylinder bore 5. More particularly, fuel and/or air may be initially introduced into cylinder bore 5. However, when piston 8 moves from BDC to TDC during the compression stroke of the combustion cycle, the fuel and/or air from cylinder bore 5 is pumped into pre-chamber assembly 20, as designated by inlet jets 65 in
When the charge from cylinder bore 5 enters pre-chamber assembly 20 through nozzles 52, electrodes 57 of spark plug 56 (
Referring to
As shown in
The convergence of outlet jets 62 forms an intense high-energy ignition source for igniting the charge within cylinder bore 5 for combustion therein. For example, at a predetermined time during the combustion cycle, outlet jets 62 are configured to converge at location 70 for complete combustion of the charge within cylinder bore 5. In one embodiment, the predetermined time for convergence of outlet jets 62 is based on a position of piston 8 within cylinder bore 5, a position of the crankshaft operably coupled to piston 8, a pressure within pre-chamber assembly 20, and/or a pressure within cylinder bore 5. By directing nozzles 52 towards location 70 at approximately the center portion of piston bowl 58, outlet jets 62 may be stretched by and entrained in a recirculating flow of air and/or fuel within piston bowl 58. More particularly, the recirculating flow of air and/or fuel is denoted by arrows 66 (
During a combustion cycle, pre-chamber assembly 20 and spark plug 56 experience increased temperatures. However, as shown in
While various embodiments of the disclosure have been shown and described, it is understood that these embodiments are not limited thereto. The embodiments may be changed, modified and further applied by those skilled in the art. Therefore, these embodiments are not limited to the detail shown and described previously, but also include all such changes and modifications.
Filing Document | Filing Date | Country | Kind |
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PCT/US2015/054592 | 10/8/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2017/062003 | 4/13/2017 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3508530 | Clawson | Apr 1970 | A |
4270498 | Occella | Jun 1981 | A |
4306526 | Schaub et al. | Dec 1981 | A |
5024193 | Graze, Jr. | Jun 1991 | A |
5555868 | Neumann | Sep 1996 | A |
5947076 | Srinivasan | Sep 1999 | A |
6854439 | Regueiro | Feb 2005 | B2 |
7216623 | Teraji et al. | May 2007 | B2 |
7438043 | Shiraishi et al. | Oct 2008 | B2 |
7950364 | Nerheim | May 2011 | B2 |
8839762 | Chiera | Sep 2014 | B1 |
8925518 | Riley et al. | Jan 2015 | B1 |
9964023 | Teslovich | May 2018 | B1 |
10125676 | Thomassin | Nov 2018 | B2 |
10557407 | Dussault | Feb 2020 | B2 |
20050247283 | Lampard | Nov 2005 | A1 |
20110005478 | Taliaferro | Jan 2011 | A1 |
20120090572 | Baxter | Apr 2012 | A1 |
20120125287 | Chiera et al. | May 2012 | A1 |
20130000598 | Tokuota et al. | Jan 2013 | A1 |
20130206122 | Chiera et al. | Aug 2013 | A1 |
20140196686 | Coldren | Jul 2014 | A1 |
20140261296 | Sotiropoulou et al. | Sep 2014 | A1 |
20150184578 | Oda et al. | Jul 2015 | A1 |
20170030315 | Bauer | Feb 2017 | A1 |
20170096932 | Chiera | Apr 2017 | A1 |
20170101922 | Loetz | Apr 2017 | A1 |
Number | Date | Country |
---|---|---|
10 2014 004943 | Feb 2015 | DE |
102014004943 | Feb 2019 | DE |
2 700 796 | Feb 2014 | EP |
2 886 689 | Dec 2006 | FR |
2886689 | Dec 2006 | FR |
201207 | Jul 1923 | GB |
2003-278548 | Oct 2003 | JP |
2007-040174 | Feb 2007 | JP |
5451490 | Mar 2014 | JP |
9845588 | Oct 1995 | WO |
Entry |
---|
International Search Report and Written Opinion dated Jan. 12, 2016 in PCT/US2015/054592. |
European Search Report and Search Opinion Received for EP Application No. 15905945.0, dated Feb. 15, 2019, 8 pages. |
Letter Exam Report issued by the China National Intellectual Property Administration, dated Feb. 3, 2020, Chinese language, for Chinese Application No. 201580883633.6; 11 pages. |
Letter Exam Report issued by the China National Intellectual Property Administration, dated Feb. 3, 2020, translated to English language, for Chinese Application No. 201580883633.6; 12 pages. |
International Preliminary Report on Patentability dated Apr. 13, 2018 in PCT/US2015/054592. |
Extended European Search Report dated Feb. 15, 2019 in corresponding EP Application No. 15905945.0. |
Number | Date | Country | |
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20200123963 A1 | Apr 2020 | US |