Internal combustion engine comprising pistons with different bowl geometries

Abstract

An internal combustion engine includes a plurality of cylinders that each have a piston. A first piston in a first cylinder has a first configuration and a second piston in a second cylinder has a second configuration. The first configuration differs from the second configuration based on different purposes for the combustion and / or exhaust output from the first and second cylinders.

Description

INTERNAL COMBUSTION ENGINE COMPRISING PISTONS WITH DIFFERENT BOWL GEOMETRIESCross-Reference to Related Application:

[0001] The present application claims the benefit of the filing date of, and priority to, U.S. Provisional Patent Application Ser. No. 63 / 551,292 filed February 8, 2024, which is incorporated herein by reference.Technical Field:

[0002] The present disclosure relates to internal combustion engine systems, and more particularly to internal combustion engines having pistons with different configurations.BACKGROUND

[0003] Internal combustion engines can include a plurality of cylinders that each have a piston that is reciprocated in the cylinder during the combustion process. The plurality of cylinders can be operated simultaneously while different ones of the cylinders provide combustion and / or exhaust outputs used for different purposes. For example, the exhaust output of one or more cylinders can be used for exhaust gas recirculation, while the exhaust output of one or more other cylinders can be used for thermal management of an aftertreatment system. Employing the same type of piston configuration in each of the plurality of cylinders may prevent, inhibit, or be less efficient in obtaining a desired cylinder output for the intended purpose. Therefore, further technological developments are desirable in this area.SUMMARY

[0004] The present disclosure relates to an internal combustion engine system having an internal combustion engine with a plurality of cylinders. A piston in at least one of the cylinders includes a first configuration, and a piston in at least one other cylinder includes a second configuration that is different that the first configuration. The first and second configurations differ from one another based on different purposes for the combustion and / or exhaust output from the first and second cylinders. For example, the first configuration can be particularly suited for hydrocarbon dosing into the cylinder for thermal management of at least one aftertreatment component, and the second configuration can be suited for maximizing combustion efficiency in the cylinder. Other example purposes are also contemplated and not precluded.

[0005] In an embodiment, an internal combustion engine system includes an internal combustion engine having a plurality of cylinders. The plurality of cylinders include a first cylinder including a first piston having a first configuration, and a second cylinder including a second piston having a second configuration. The first configuration is different than the second configuration to accommodate different angles of fuel injection.

[0006] In an embodiment, an internal combustion engine includes a first cylinder having a first piston and a second cylinder having a second piston. The first piston includes a first combustion bowl configuration, and the second piston includes a second combustion bowl configuration. The first combustion bowl configuration is different than the second combustion bowl configuration.

[0007] This summary is provided to introduce a selection of concepts that are further described below in the illustrative embodiments. 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. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. l is a schematic depiction of an internal combustion engine system including an internal combustion engine including plurality of cylinders.

[0009] FIG. 2 is a schematic depiction of one embodiment of a cylinder of the internal combustion engine of FIG. 1.

[0010] FIG. 3 is a schematic depiction of another embodiment of a cylinder of the internal combustion engine of FIG. 1 that can be employed in conjunction with the embodiment of FIG. 2.

[0011] FIG. 4 is a schematic depiction comparing the combustion bowl configurations of the pistons of FIGs. 2 and 3.DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0012] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the invention as illustrated therein as would normally occur to one skilled in the art to which the invention relates are contemplated herein.

[0013] Referring to FIGs. 1-4, an internal combustion engine system 10 includes an internal combustion engine 12 having a plurality of cylinders 14, 16, 18, 20, 22, 24. The plurality of cylinders include a first cylinder 14 including a first piston 100 having a first configuration, and a second cylinder 24 including a second piston 130 having a second configuration. The first configuration accommodates a first angle of fuel injection, and the second configuration accommodates a second angle of fuel injection. The first angle of fuel injection is different than the second angle of fuel injection.

[0014] In an embodiment, internal combustion engine 12 includes first cylinder 14 having first piston 100 and second cylinder 24 having second piston 130. First piston 100 includes a first combustion bowl configuration 102, and second piston 130 includes a second combustion bowl configuration 132. First combustion bowl configuration 102 is different than second combustion bowl configuration 132.

[0015] Referencing FIG. 1, internal combustion engine system 10 is depicted having internal combustion engine 12. Engine 12 is an internal combustion engine of any type, and can be a spark ignited or a compression ignition engine. In certain embodiments, the engine 12 may be any engine type producing emissions that may include an exhaust gas recirculation (EGR) system 28. Engine 12 includes a plurality of cylinders 14, 16, 18, 20, 22, 24. Engine 12 includes an inline 6 cylinder arrangement for illustration purposes only and is not limited to such. The number of cylinders may be any number of two or morecylinders suitable for an engine, and the arrangement of cylinders in engine 12 may be inline, V, or any suitable arrangement.

[0016] Engine 12 includes first cylinder 14, second cylinder 24, and, in certain embodiments, a plurality of additional cylinders 16, 18, 20, 22. In an embodiment, first cylinder 14 is a thermal management cylinder that can be operated in response to one or more thermal management conditions to thermally manage engine 12 and / or one more components of an aftertreatment system 26. In an embodiment, second cylinder 24 is a primary EGR cylinder that can be dedicated during all or some operating conditions to provide its entire exhaust output for exhaust gas recirculation through EGR system 28. Additional cylinders 16, 18, 20, 22 can be involved or not involved in exhaust gas recirculation and / or thermal management operations.

[0017] In the illustrated embodiment, first cylinder 14 and additional cylinders 16, 18, 20, 22 are secondary cylinders or not primary EGR cylinders 14b. For example, all or a portion of cylinders 14, 16, 18, 20, 22 can be completely flow isolated from the EGR system 28 at exhaust 30 of engine 12. All cylinders 14, 16, 18, 20, 22, 24 receive EGR flow and are flow connected to the second cylinder 24 at intake 32 of engine 12. In other embodiments, one or more of the additional cylinders 16, 18, 20, 22 are connected to provide at least some exhaust flow to the EGR system 28 and / or to provide exhaust flow to aftertreatment system 26.

[0018] The term primary EGR, as utilized herein, includes any EGR arrangement wherein, during at least certain operating conditions, the entire exhaust output of second cylinder 24 (and any other primary EGR cylinders) is recirculated to the engine intake 32 is a primary EGR cylinder. A primary EGR cylinder typically, at least during primary EGR operation, includes exhaust divided from one or more of the remaining cylinders that are not primary EGR cylinders.

[0019] Internal combustion system 10 includes intake 32 with an intake manifold 38 to provide an intake air flow to cylinders 14, 16, 18, 20, 22, 24. Intake 32 includes aturbocharger compressor 34 to compress the intake air flow, and an intake conduit 36 connected to intake manifold 38. Intake 32 may also include an intake air throttle 40 and a charge air cooler 42 connected to intake conduit 36 between intake air throttle 40 and compressor 34.

[0020] Internal combustion engine system 10 also includes exhaust 30 to receive an exhaust flow from cylinders 14, 16, 18, 20, 22 and provide all or a part of the exhaust flow to aftertreatment system 26. Aftertreatment system 26 may include one or more aftertreatment components, such as an oxidation catalyst 44, particulate filter 46, and / or a selective catalytic reduction catalyst 48. Other embodiment contemplate other aftertreatment components, such as ammonia oxidation catalysts, three-way catalysts, etc.

[0021] Exhaust 30 also includes an exhaust conduit 50 connecting first and second exhaust manifold portions 52, 54 to turbocharger compressor 56 and aftertreatment system 26. In an embodiment, first exhaust manifold portion 52 receives exhaust flow from cylinders 14, 16, and 18 and provides the exhaust flow to exhaust conduit 50. In an embodiment, second exhaust manifold portion 54 includes a first portion 58 that collects exhaust flow from cylinders 20, 22 and provides the exhaust flow to exhaust conduit 50. Second exhaust manifold 54 may also include a second portion 60 that is flow isolated, or is isolatable, from first portion 58 to direct exhaust flow from second cylinder 24 to EGR system 28.

[0022] EGR system 28 includes an EGR conduit 62 connected to second part 60 of second exhaust manifold 54. EGR system 28 may also include an EGR valve 64 for controlling EGR flow through EGR conduit 62, and an EGR cooler 66 for cooling EGR flow. EGR cooler 66 can be connected upstream of EGR valve 64 as shown or downstream. An EGR bypass (not shown) may also be provided to bypass EGR cooler 66. EGR conduit 62 may be connected to intake conduit 36 and / or intake manifold 38.

[0023] Internal combustion engine system 10 further includes a fuel system 70 with a fuel source 76 connected to each of the cylinders 14, 16, 18, 20, 22, 24. Referring further toFIGs. 2-4, in certain embodiments, first cylinder 14 and, if similarly provided with a similarly configured piston 100 as first cylinder 14, one or more of the additional cylinders 16, 18, 20, 22 may include a first direct injector 72 connected to and injecting fuel from fuel source 74. Second cylinder 24 and one or more of the additional cylinders 16, 18, 20, 22 with a piston configured similarly to piston 130 may include a second direct injector 74 for providing fuel from fuel source 76.

[0024] A direct injector 72, 74, as utilized herein, includes any fuel injection device that injects fuel directly into the cylinder volume, and is capable of delivering fuel into the cylinder. Direct injector 72, 74 may be structured to inject fuel into the cylinder toward a combustion bowl of the piston located in the cylinder. In certain embodiments, direct injector 72 is structured to inject fuel into a first combustion bowl 104 of first piston 100 including first combustion bowl configuration 102, while second direct injector 74 is structured to inject fuel into a second combustion bowl 134 of second piston 130 that includes second combustion bowl configuration 132.

[0025] Combustion bowl configuration 102 for first piston 100 allows a first spray angle Al that is narrower than a second spray angle A2 for second director injector 74 for combustion bowl configuration 132 of second piston 130. The first spray angle Al of first direct injector 72 into first cylinder 14 is suitable for hydrocarbon dosing due to less wetting of the cylinder wall 88 provided by the more narrow angle into the cylinder volume, allowing more hydrocarbons to enter the exhaust flow for thermal management of one or more of the aftertreatment components 44, 46, 48, such as during a regeneration event for a filter or catalyst. In an embodiment, a re-entrant combustion bowl configuration is used for first combustion bowl configuration 102.

[0026] The second spray angle A2 of second direct injector 74 allows utilization of the second combustion bowl configuration 132 for second piston 130. In an embodiment, second combustion bowl configuration 132 is as an open bowl configuration. An open combustion bowl configuration provides increased brake thermal efficiency (BTE) over aresultant combustion bowl configuration such as employed with first piston 100 due to a reduction in in-cylinder heat loss for second piston 130.

[0027] As shown further in FIGs. 2-3, first and second pistons 100, 130 in cylinders 14, 24 are each connected to a crankshaft (not shown) via a connecting rod 80. Pistons 110, 130 move in their respective combustion chambers 82, 84 between a top dead center (TDC) position and a bottom dead center (BDC) position. Cylinders 14, 24 each include at least one exhaust valve (not shown) and at least one intake valve (not shown) that are operable to selectively open and close an exhaust port and intake port, respectively, in fluid communication with combustion chamber 82, 84.

[0028] First direct injector 72 injects fuel from fuel source 76 directly into combustion chamber 82 at first spray angle Al in a predetermined pulse amount, width, duration, timing and number of pulses in response to a fueling command. Second direct injector 74 is also shown for directing fuel from fuel source 76 directly into combustion chamber 84 at second spray angle A2 in a predetermined pulse amount, width, duration, timing and number of pulses in response to a fueling command. First and second cylinders 14, 24 may also include a spark plug (not shown) if engine 12 is a spark-ignited engine to ignite the air / fuel mixture in combustion chambers 82, 84 according a spark timing command that times ignition relative the position of pistons 100, 130 in combustion chambers 82, 84.

[0029] First piston 100 includes a first skirt 106 connected to connecting rod 80 and a first crown 108 connected to first skirt 106. First combustion bowl 104 is formed in a combustion surface of first crown 108. Second piston 130 includes a second skirt 136 connected to connecting rod 80 and connected to a second crown 138. Second combustion bowl 134 is formed in a combustion surface of second crown 138.

[0030] As discussed above, first combustion bowl 104 is a re-entrant combustion bowl and second combustion bowl 134 is an open combustion bowl in an embodiment of the present disclosure. A graphical comparison between the two configurations is provided in FIG. 4. First and second pistons 100, 130 each extend along and are symmetrical about acenterline axis Al . Only one side of first and second combustion bowls 104, 134 are shown in FIG. 4.

[0031] First combustion bowl 104 includes a first outer crown surface 110 at an outer perimeter of the upper combustion surface of first piston 100. First combustion bowl 104 also includes a first interior crown surface 112 at centerline axis Al that is recessed into first combustion bowl 104 relative to first outer crown surface 110. First combustion bowl 104 further includes a first sloped surface 114 extending from first interior crown surface 112 to a first pocket 116. A first curvilinear sidewall 118 having a compound curvature connects first pocket 116 to outer crown surface 110. In the illustrated embodiment, first curvilinear sidewall 118 has an intermediate convex portion 120 that protrudes radially inwardly toward the first combustion bowl 104.

[0032] Second combustion bowl 134 includes a second outer crown surface 140 at an outer perimeter of the upper combustion surface of second piston 130. Second combustion bowl 134 also includes a second interior crown surface 142 at centerline axis Al that is recessed into second combustion bowl 134 relative to second outer crown surface 140.Second interior crown surface 142 is recessed along centerline axis A less than first interior crown surface 112 of first piston 100.

[0033] Second combustion bowl 134 also includes a second sloped surface 144 extending from second interior crown surface 142 to a second pocket 146 that is located further radially outwardly from centerline axis Al than first pocket 116, but second pocket 144 is not as deep along centerline axis Al as first pocket 116. For example, first pocket 116 has a first depth DI along centerline axis Al, and second pocket 146 has a second depth D2 along centerline axis Al that is less than first depth DI. First pocket 116 forms a first width W1 from centerline axis Al that is less than a second width W2 of second pocket 146. A second curvilinear sidewall 118 connects second pocket 146 to second outer crown surface 140. Second curvilinear sidewall 118 lacks an intermediate convex portion.

[0034] The first depth DI and first width W1 of first pocket 116 of first combustion bowl 104 allows a narrower angle first direct injector 72 to be employed at first cylinder 14 for hydrocarbon dosing without wetting, or with reduced wetting, of the inner wall surface 88 of first cylinder 14. The second depth D2 and second width W2 of second pocket 146 of second combustion bowl 134 allows a wider angle second direct injector 74 to be employed at second cylinder 24 for improved combustion efficiency and greater BTE at second cylinder 24 than first cylinder 14.

[0035] The additional cylinders 16, 18, 20, 22 can be arranged identically to one of first and second cylinders 14, 24. For example, additional cylinders 16, 18, 20, 22 are identical to second cylinder 24 in an embodiment, and include a piston like second piston 130 and a fuel injector like second fuel injector 74.

[0036] According to one aspect of the present disclosure, an internal combustion engine system includes an internal combustion engine with a plurality of cylinders. The plurality of cylinders include a first cylinder including a first piston having a first configuration and a second cylinder including a second piston having a second configuration. The first configuration is different than the second configuration to accommodate different angles of fuel injection.

[0037] In an embodiment, the first configuration is a first combustion bowl configuration, and the second configuration is a second combustion bowl configuration.

[0038] In a further embodiment, the first combustion bowl configuration is a re-entrant combustion bowl in a first crown of the first piston, and the second combustion bowl configuration is an open combustion bowl in a second crown of the second piston.

[0039] In yet a further embodiment, the re-entrant combustion bowl includes a first width across the first crown and a first depth into first the crown, and the open combustion bowl includes a second width across the second crown and a second depth into the secondcrown. The first width is less than the second width, and the first depth is greater than the second depth.

[0040] In a further embodiment, the system includes a first fuel injector having a first spray angle configured to inject fuel cylinder into the first combustion bowl configuration, and a second fuel injector having a second spray angle configured to inject fuel into the second combustion bowl configuration. The second spray angle is wider than the first spray angle.

[0041] In an embodiment, the internal combustion engine includes an intake and an exhaust, the exhaust including at least one aftertreatment component. The first cylinder is connected to the at least one aftertreatment component via the exhaust, and the second cylinder is connected to the intake.

[0042] In a further embodiment, the intake includes an intake manifold and an intake conduit connected to the intake manifold. The exhaust includes at least a first exhaust manifold and a second exhaust manifold. The exhaust further includes an exhaust conduit connected to at least the first exhaust manifold. The first cylinder is connected to the first exhaust manifold, and the second cylinder is connected to the second exhaust manifold and the intake conduit or the intake manifold.

[0043] In yet a further embodiment, the intake includes a compressor connected to the intake conduit, and the exhaust includes a turbine connected to the exhaust conduit.

[0044] In yet a further embodiment, the second cylinder is connected to the intake conduit or the intake manifold with an exhaust gas recirculation conduit.

[0045] In yet a further embodiment, the system includes an exhaust gas recirculation valve to control exhaust flow through the exhaust gas recirculation conduit, and an exhaust gas recirculation cooler to cool exhaust flow through the exhaust gas recirculation conduit.

[0046] In yet a further embodiment, the second exhaust manifold includes a first portion connected to the exhaust conduit, and a second portion connecting the second cylinder to the exhaust gas recirculation conduit.

[0047] In yet a further embodiment, the second portion of the second exhaust manifold is flow isolated from the first portion of the second exhaust manifold.

[0048] In yet a further embodiment, the internal combustion engine includes a plurality of additional cylinders. Each of the additional cylinders includes a piston having the second configuration.

[0049] In yet a further embodiment a first part of the additional cylinders is connected to the first exhaust manifold, and a second part of the additional cylinders is connected to the second exhaust manifold.

[0050] In yet a further embodiment, the at least one aftertreatment component includes an oxidation catalyst, a particulate filter, and / or a selective catalytic reduction catalyst.

[0051] In an embodiment, the first cylinder is a thermal management cylinder that receives hydrocarbons for thermally managing at least one aftertreatment component, and the second cylinder is a dedicated exhaust gas recirculation cylinder.

[0052] According to another aspect of the disclosure, an internal combustion engine is disclosed. The engine includes a first cylinder including a first piston and a second cylinder including a second piston. The first piston includes a first combustion bowl configuration, and the second piston includes a second combustion bowl configuration. The first combustion bowl configuration is different than the second combustion bowl configuration.

[0053] In an embodiment, the first combustion bowl configuration is a re-entrant combustion bowl in a first crown of the first piston. The second combustion bowl configuration is an open combustion bowl in a second crown of the second piston.

[0054] In an embodiment, the re-entrant combustion bowl includes a first width across the first crown and a first depth into first the crown. The open combustion bowl includes a second width across the second crown and a second depth into the second crown. The first width is less than the second width, and the first depth is greater than the second depth.

[0055] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described. Those skilled in the art will appreciate that many modifications are possible in the example embodiments without materially departing from this invention.Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

[0056] In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and / or “a portion” is used the item can include a portion and / or the entire item unless specifically stated to the contrary.

Claims

WHAT IS CLAIMED IS:

1. An internal combustion engine system, the system comprising: an internal combustion engine including a plurality of cylinders, the plurality of cylinders including: a first cylinder including a first piston having a first configuration; and a second cylinder including a second piston having a second configuration, wherein the first configuration accommodates a first angle of fuel injection, the second configuration accommodates a second angle of fuel injection, and the first angle of fuel injection is different than the second angle of fuel injection.

2. The system of claim 1, wherein: the first configuration is a first combustion bowl configuration; and the second configuration is a second combustion bowl configuration.

3. The system of claim 2, wherein: the first combustion bowl configuration is a re-entrant combustion bowl in a first crown of the first piston; and the second combustion bowl configuration is an open combustion bowl in a second crown of the second piston.

4. The system of claim 3, wherein: the re-entrant combustion bowl includes a first width across the first crown and a first depth into first the crown; the open combustion bowl includes a second width across the second crown and a second depth into the second crown; and the first width is less than the second width, and the first depth is greater than the second depth.

5. The system of claim 2, further comprising: a first fuel injector having a first spray angle configured to inject fuel cylinder into the first combustion bowl configuration; anda second fuel injector having a second spray angle configured to inject fuel into the second combustion bowl configuration, wherein the second spray angle is wider than the first spray angle.

6. The system of claim 1, wherein: the internal combustion engine includes an intake and an exhaust, the exhaust including at least one aftertreatment component; the first cylinder is connected to the at least one aftertreatment component via the exhaust; and the second cylinder is connected to the intake.

7. The system of claim 6, wherein: the intake includes an intake manifold and an intake conduit connected to the intake manifold; the exhaust includes at least a first exhaust manifold and a second exhaust manifold, the exhaust further including an exhaust conduit connected to at least the first exhaust manifold; and the first cylinder is connected to the first exhaust manifold; and the second cylinder is connected to the second exhaust manifold and the intake conduit or the intake manifold.

8. The system of claim 7, wherein: the intake includes a compressor connected to the intake conduit; and the exhaust includes a turbine connected to the exhaust conduit.

9. The system of claim 7, wherein the second cylinder is connected to the intake conduit or the intake manifold with an exhaust gas recirculation conduit.

10. The system of claim 9, further comprising: an exhaust gas recirculation valve to control exhaust flow through the exhaust gas recirculation conduit; andan exhaust gas recirculation cooler to cool exhaust flow through the exhaust gas recirculation conduit.

11. The system of claim 9, wherein the second exhaust manifold includes: a first portion connected to the exhaust conduit; and a second portion connecting the second cylinder to the exhaust gas recirculation conduit.

12. The system of claim 11, wherein the second portion of the second exhaust manifold is flow isolated from the first portion of the second exhaust manifold.

13. The system of claim 11, wherein the internal combustion engine includes a plurality of additional cylinders, each of the additional cylinders including a piston having the second configuration.

14. The system of claim 13, wherein: a first part of the additional cylinders is connected to the first exhaust manifold; and a second part of the additional cylinders is connected to the second exhaust manifold.

15. The system of claim 6, wherein the at least one aftertreatment component includes an oxidation catalyst, a particulate filter, and / or a selective catalytic reduction catalyst.

16. The system of claim 1, wherein: the first cylinder is a thermal management cylinder that receives hydrocarbons for thermally managing at least one aftertreatment component; and the second cylinder is a dedicated exhaust gas recirculation cylinder.

17. An internal combustion engine, the engine comprising: a first cylinder including a first piston, the first piston including a first combustion bowl configuration; anda second cylinder including a second piston, the second piston including a second combustion bowl configuration, wherein the first combustion bowl configuration is different than the second combustion bowl configuration.

18. The engine of claim 17, wherein: the first combustion bowl configuration is a re-entrant combustion bowl in a first crown of the first piston; and the second combustion bowl configuration is an open combustion bowl in a second crown of the second piston.

19. The engine of claim 18, wherein: the re-entrant combustion bowl includes a first width across the first crown and a first depth into first the crown; the open combustion bowl includes a second width across the second crown and a second depth into the second crown; and the first width is less than the second width, and the first depth is greater than the second depth.

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