WO2021158203A1

WO2021158203A1 - Engine arrangement and method including exhaust gas recirculation valve, and valve usable in the engine arrangement and method

Info

Publication number: WO2021158203A1
Application number: PCT/US2020/016346
Authority: WO
Inventors: Thomas Mark Louzon
Original assignee: Volvo Truck Corporation
Priority date: 2020-02-03
Filing date: 2020-02-03
Publication date: 2021-08-12

Abstract

An exhaust gas recirculation (EGR) valve includes a valve body having a passage including an inlet port connected to an exhaust line, two outlet ports, and a valve plug movable between a first position in which a sealing surface extending along at least part of a circumference around an axis of the valve plug closes adjacent a valve seat of the passage so that exhaust gas flows through the passage from the inlet port to the first one of the two outlet ports and exhaust gas flow to the second one of the two outlet ports is blocked and a second position in which exhaust gas flows through the passage from the inlet port to the second one of the two outlet ports and exhaust gas flow to the first one of the two ports is blocked by a side portion of the valve plug.

Description

ENGINE ARRANGEMENT AND METHOD INCLUDING

EXHAUST GAS RECIRCULATION VALVE, AND VALVE

USABLE IN THE ENGINE ARRANGEMENT AND METHOD

BACKGROUND AND SUMMARY

[0001] The present invention relates generally to an engine arrangement including an exhaust gas recirculation valve and a method of operating such an engine arrangement and, more particularly, to a valve adapted for use in the engine arrangement and method.

[0002] Many diesel engine arrangements include an exhaust gas recirculation (EGR) line extending between an exhaust line and an intake line. The EGR line typically includes an EGR cooler and an EGR valve. EGR valves currently in production are ordinarily installed either before or after an EGR cooler in the exhaust recirculation system. When the EGR valve is opened a flow path is provided through the recirculation system. A back pressure device such as a variable geometry turbo (VGT) or other exhaust back-pressure device such as an exhaust pressure valve is required to generate enough pressure in the exhaust line to force recirculation exhaust into the intake system. These devices add cost to the engine arrangement and their use can result in reduced engine efficiency. [0003] It is also known to intentionally adjust the degree of combustion in certain cylinders of an engine. Unbumt hydrocarbons can, however, result in clogging of the EGR cooler and varnishing of engine components.

[0004] It is desirable to reduce or avoid the need for back pressure devices in engine arrangements. It is also desirable to reduce or avoid the tendency of unbumt hydrocarbons to plug the EGR cooler or varnish engine components.

[0005] According to an aspect of the present invention, an engine arrangement comprises an internal combustion engine comprising a plurality of cylinders, an intake line arranged to deliver intake gas to the plurality of cylinders, an exhaust manifold comprising an exhaust manifold portion arranged to receive exhaust gas exiting the plurality of cylinders, a main exhaust line, an exhaust line connected at a first end to the exhaust manifold portion and at a second end to an exhaust gas recirculation (EGR) valve, an EGR line between the EGR valve and the intake line, and the EGR valve comprising a valve body having a passage comprising an inlet port connected to the exhaust line, two outlet ports, a first one of the two outlet ports being connected to the main exhaust line and a second one of the two outlet ports being connected to the EGR line, and a valve plug movable between a first position in which a sealing surface extending along at least part of a circumference around an axis of-the valve plug closes adjacent a valve seat of the passage so that exhaust gas flows through the passage from the inlet port to the first one of the two outlet ports and exhaust gas flow to the second one of the two outlet ports is blocked and a second position in which exhaust gas flows through the passage from the inlet port to the second one of the two outlet ports and exhaust gas flow to the first one of the two ports is blocked by a side portion of the valve plug. [0006] According to another aspect of the invention a valve assembly comprises a valve body having a passage comprising an inlet port and two outlet ports, and a valve plug movable between a first position in which a sealing surface extending along at least part of a circumference around an axis of the valve plug closes adjacent a valve seat of the passage and so that gas is adapted to flow through the passage from the inlet port to the first one of the two outlet ports and gas flow to the second one of the two outlet ports is blocked and a second position in which gas flows through the passage from the inlet port to the second one of the two outlet ports and exhaust gas flow to the first one of the two ports is blocked by a side portion of the valve plug.

[0007] According to another aspect of the invention, a method for operating an engine arrangement is provided where the engine arrangement comprises an internal combustion engine comprising a plurality of cylinders, an intake line arranged to deliver intake gas to the plurality of cylinders, an exhaust manifold comprising an exhaust manifold portion arranged to receive exhaust gas exiting the plurality of cylinders, a main exhaust line, an exhaust line connected at a first end to the exhaust manifold portion and at a second end to an exhaust gas recirculation

(EGR) valve, an EGR line between the EGR valve and the intake line, and the EGR valve comprising a valve body having a passage comprising an inlet port connected to the exhaust line, two outlet ports, a first one of the two outlet ports being connected to the main exhaust line and a second one of the two outlet ports being connected to the EGR line, and a valve plug movable between a first position in which a sealing surface extending along at least part of a circumference around an axis of the valve plug closes adjacent a valve seat of the passage and so that exhaust gas flows through the passage from the inlet port to the first one of the two outlet ports and exhaust gas flow to the second one of the two outlet ports is blocked and a second position in which exhaust gas flows through the passage from the inlet port to the second one of the two outlet ports and exhaust gas flow to the first one of the two ports is blocked by a side portion of the valve plug. The method comprises operating the engine so that exhaust gas from the plurality of cylinders is received in the manifold portion and flows to the inlet port, moving the valve plug to the first position so that substantially all of the exhaust gas from the plurality of cylinders flows to the main exhaust line, and moving the valve plug from the first position toward the second position so that at least some of the exhaust gas from the plurality of cylinders flows into the EGR line.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The features and advantages of the present invention are well understood by reading the following detailed description in conjunction with the drawings in which like numerals indicate similar elements and in which:

[0009] FIG. 1 is a schematic view of an engine arrangement according to an aspect of the present invention;

[0010] FIGS. 2A1, 2B1, and 2C1 are cross-sectional views of a valve according to another aspect of the present invention, and FIGS. 2A2, 2B2, and 2C2 are cross-sectional views of the valve shown in FIGS. 2A1, 2B1, and 20, respectively, rotated 90° about a longitudinal axis of a valve plug of the valve;

[0011] FIGS. 3A1, 3B1, and 30 are cross-sectional views of a valve according to another aspect of the present invention, and FIGS. 3A2, 3B2, and 3C2 are cross-sectional views of the valve shown in FIGS. 3A1, 3B1, and 30, respectively, rotated 90° about a longitudinal axis of a valve plug of the valve; [0012] FIGS. 4A, 4B, and 4C are cross-sectional views of a valve according to yet another aspect of the present invention; and

[0013] FIGS. 5A-5D are cross-sectional view of different sealing surfaces and valve seats for valves according to aspects of the present invention.

[0014] FIG. 6 is a perspective view of a valve plug according to an aspect of the present invention.

DETAILED DESCRIPTION

[0015] An engine arrangement 21 according to an aspect of the present invention is shown in

FIG. 1 and comprises an internal combustion engine 23 comprising a plurality of cylinders 25.

The engine arrangement 21 further comprises an intake line 27 arranged to deliver intake gas to the plurality of cylinders 25. An intake manifold 27a may be provided upstream of the plurality of cylinders 25. An exhaust manifold 29 comprising a first exhaust manifold portion 29b arranged to receive exhaust gas exiting a first set 25b of the plurality of cylinders and a second exhaust manifold portion 29a arranged to receive exhaust gas exiting a second set 25a of the plurality of cylinders 25. The second set 25 a and the first set 25b of the plurality of cylinders 25 can each comprise one or more cylinders.

[0016] The engine arrangement further comprises a main exhaust line 31. A first exhaust line

35 is connected at a first end 35a thereof to the second exhaust manifold portion 29b and at a second end 35b to an exhaust gas recirculation (EGR) valve 37, An EGR line 39 is provided between the EGR valve 37 and the intake line 27, A second exhaust line 33 is connected at a first end 33a thereof to the second exhaust manifold portion 29a and at a second end 33b connected to the main exhaust line 31 , The second exhaust line 33 may be omitted or may be considered to constitute a point of connection between the second exhaust manifold portion 29a and the main exhaust line 31.

[0017] Except where otherwise indicated, the invention is described herein in connection with an engine arrangement 21 wherein there are plural exhaust manifolds 29a and 29b, however, it will be appreciated that the invention is also applicable to engine arrangements with a single exhaust manifold. The invention is also described, except where otherwise indicated, in connection with an engine arrangement 21 wherein an EGR valve 37 is provided in one exhaust line 35 from one exhaust manifold 29b and another exhaust line 33 has no EGR valve, however, it will be appreciated that an EGR valve could be provided in each exhaust line associated with each exhaust manifold or in more than one exhaust line associated with more than two exhaust manifolds, i.e. some but not all of two or more exhaust manifolds.

[0018] As seen in the embodiment shown in FIGS. 2A1-2C2, the EGR valve 37 can comprise a valve body 41 having a passage 43 comprising an inlet port 45 connected to the first exhaust line

35, and two outlet ports 47 and 49, a first one 47 of the two outlet ports being connected to the main exhaust line 31 and a second one 49 of the two outlet ports being connected to the EGR line 39, The EGR valve 37 further comprises a valve plug 51 movable axially between a first position (seen in FIGS. 2A1 and 2A2) in which a sealing surface 53 of the valve plug along at least part of a, usually an entirety of the, circumference around an axis L of the valve plug closes adjacent a valve seat 55 of the passage 43 so that exhaust gas flows through the passage from the inlet port 45 to the first one 47 of the two outlet ports and exhaust gas flow to the second one 49 of the two outlet ports is blocked and a second position (seen in FIGS. 2C1 and 2C2) in which exhaust gas flows through the passage from the inlet port to the second one of the two outlet ports and exhaust gas flow to the first one of the two ports is blocked by a main body portion 67 of the valve plug. In the embodiment shown in FIGS. 2A1-2C2, the sealing surface 53 of the valve plug 51 extending along at least part of a circumference around the axis of the valve plug closes adjacent a valve seat 55 of the passage 43 by being moved axially.

[0019] In the embodiment illustrated in FIGS. 2A1-2C2, the sealing surface 53 and the valve seat 55 are annular surfaces extending along at least part of and usually the entire circumference around the longitudinal axis L of the valve plug 51, The sealing surface 53 is seated against the valve seat 55 when the valve plug 51 is in the first position (FIGS. 2A1 and 2A2). In the embodiment of FIGS. 2A1-2C2, the sealing surface 53 and the valve seat 55 extend entirely around the longitudinal axis L of the valve plug 51, however, as shown in phantom in FIG. 2A2, part of the valve seat 55 may include a recess 59 that extends into the valve body 41 which can facilitate permitting more exhaust gas to flow through toward the first one 47 of the two outlet ports than if the size of contacting surfaces of the sealing surface and the valve seat were constant at all points around the longitudinal axis of the valve plug.

[0020] The valve plug 51 shown in the embodiment of FIGS. 2A1-2C2 comprises a front portion 61 (FIG. 2A1), a rear portion 63 (FIG. 2A1), and a side portion 65 (FIG. 2A1) between the front surface and the rear portion. The sealing surface 53 comprises part of the side portion

65 (FIG. 2A1). In the illustrated embodiment, both of the sealing surface 53 and the valve seat

55 are frustoconical with cone angles that define the same angle (or slightly different angles) with respect to the longitudinal axis L of the valve plug 51 to create an annular line-of-contact seal. It will be appreciated, however, that one or both of the sealing surface 53 and the valve seat

55 can be perpendicular to the longitudinal axis L of the valve plug 51, or can be in the form of a convex curve. FIG. 5 A shows part of an EGR valve with a frustoconical sealing surface 53 on a valve plug 51 and a frustoconical valve seat 55 on a valve body 41; FIG. 5B shows part of an EGR valve with a convex sealing surface 53’ on a valve plug 51 ’ and a convex valve seat 55 on a valve body 4 V; FIG. 5C shows part of an EGR valve with a sealing surface 53” on a valve plug

51 ” and a valve seat 55” on a valve body 41 ” that are perpendicular to the longitudinal axis L of the valve plug 51”; and FIG. 5D shows that sealing surfaces 53, 53 53” (53’ and 53” shown in phantom) and valve seats 55, 55’, 55” (55’ and 55” shown in phantom)of different combinations can be combined (convex and/or perpendicular sealing surfaces and valve seats shown in phantom can be exchanged for either or both of the illustrated frustoconical surfaces).

[0021] The sealing surface 53 and the valve seat 55 in the embodiment of FIGS. 2A1-2C2 will ordinarily have at least a line of contact around an entire circumference of the longitudinal axis L of the valve plug 51 when the valve is in the position shown in FIGS. 2A1-2A2 so that flow to the second one 49 of the two outlet ports is at least partially and, more preferably, completely blocked. It is also possible that, when a recess 59 is provided, flow will not be completely blocked even though the valve is in the position shown in FIGS. 2A1-2A2,

[0022] For purposes of the present application, except where otherwise expressly indicated, references to flow to an outlet port being “blocked” does not mean that the outlet port is

“completely” blocked in the sense of there being no flow permitted to the outlet port but, rather, that the outlet port is more blocked than when the valve plug is in a position that permits a maximum amount of flow to that outlet port.

[0023] In the embodiment of FIGS. 2A1-2C2, the side portion 65 (FIG. 2A1) comprises a main body portion 67, and the sealing surface 53 comprises a first end 53 a (FIG. 2A1) furthest from the main body portion and a second end 53b (FIG. 2A1) closest to the main body portion, the first end being disposed radially outward of the second end relative to a longitudinal axis L of the valve plug 51. In the embodiment of FIGS. 2A1-2C2, when the valve plug 51 is axially moved to the position shown in FIGS. 2C1-2C2, exhaust flow to the first one 47 of the two outlet ports is blocked by the main body portion 67 of the side portion 65 (FIG. 2A1) of the valve plug, but not completely blocked, because a limited amount of flow is permitted through a space 69 between the main body portion and the interior surface of the passage 43.

[0024] FIGS. 3A1-3C2 show another embodiment of the EGR valve 137 wherein it is possible to completely block flow to the first outlet port 147 while permitting flow to the second outlet port 149 (FIGS. 3B1-3B2) and to completely block flow to the second outlet port while permitting flow to the first outlet port (FIGS. 3A1 -3A2). In the embodiment shown in FIGS.

3A1-3C2, the valve plug 151 and the portion of the passage 143 in which it is axially movable form a tight fit such that, when the valve plug is in the position shown in FIGS. 3A1-3A2 in which flow from the inlet port 145 to the first outlet port 147 is permitted, flow to the second outlet port 149 is blocked, typically completely blocked. Gaskets or other suitable sealing means

(not shown) may be provided to facilitate completely blocking flow to the second outlet port. In the position shown in FIGS. 3A1-3A2, the sealing surface 153 of the valve plug 151 comprises an annular surface of the valve plug that extends in the direction of the longitudinal axis L of the valve plug at the front portion 161 of the valve plug, and the valve seat 155 comprises an annular portion of the passage extending in the direction of the longitudinal axis of the valve plug to one side of a portion of the passage 143 that is adjacent to the sealing surface when the valve plug

151 is in the position shown in FIGS. 3A1-3A2, When the valve plug 151 is axially moved to the position shown in FIGS. 3B1-3B2, the side portion 165 of the valve plug ordinarily, but not necessarily, completely blocks flow to the first outlet port 147. Gaskets or other suitable sealing means (not shown) may be provided to facilitate completely blocking flow to the first outlet port.

Unlike the valve plug 51 shown in FIGS. 2A1-2C2 wherein there is a frustoconical sealing surface 53, the valve plug 151 is cylindrical over at least the portion of its length from the front portion 161 to at least the part of the side portion 165 that blocks flow to the first outlet port 147.

The portion of the passage 143 leading to the first outlet port 147 is ordinarily of a smaller diameter than the portion of the passage leading to the second outlet port 149 but may be of the same diameter. As with the embodiment shown in FIGS. 2A1-2C2, in the embodiment shown in

FIGS. 3A1-3C2, the sealing surface 153 of the valve plug extending circumferentially around the axis L of the valve plug 151 closes adjacent a valve seat 155 of the passage 143 by being moved axially.

[0025] In the embodiments shown in FIGS. 2A1-2C2 and 3A1-3C2, the main body portion 67 and 167, respectively, includes a recess 71 and 171, respectively, extending, in the embodiment shown in FIGS. 2A1-2C2 from the second end 53b (FIG. 2A1) of the sealing surface 53 of the valve plug 51 toward the longitudinal axis L of the valve plug and, in the embodiment shown in

(FIGS . 3 A 1 -3C2), from the front portion 161 of the valve plug 151 or some point along the side portion 165 near the front portion of the valve plug toward the longitudinal axis L of the valve plug. The recess 71 and 171 shown in FIGS. 2A1-2C2 and 3A1-3C2 is in the form of a beveled, planar surface that may extend across part of or an entire width of the valve plug 51 and 151 and that is formed at an acute angle to the longitudinal axis L of the valve plug. It will be appreciated, however, that the recess 71 and 171 might have other shapes, such as non-planar, curved shapes, as long as the recess performs the function of permitting flow past the front portion 61 (FIG. 2A1) and 161 of the valve plug 51 and 151 to the second outlet port 49 and 149 when the valve plug is moved axially from the position shown in FIGS. 2A1 and 3A1 toward the position shown in FIGS, 2C1 and 3C1. For example, FIG. 6 shows a valve plug 351 in which the recess is in the form of a notch 371 starting below a portion of the valve plug that functions as a sealing surface 353. Additionally, the valve body 41 and 141 may have a recess, such as the recess 59 shown in phantom in the valve body 41 in FIG. 2A2.

[0026] Another alternative embodiment of the EGR valve 237 is shown in FIGS. 4A-4C. The

EGR valve 237 is a rotary three-way valve with an inlet port 245, a passage 243, a first outlet port 247, and a second outlet port 249, The passage 243 is formed between a valve body 241 and a valve plug 251 that is rotatable relative to the valve body. By rotating the valve plug 251 to the position shown in FIG. 4A, flow to the first outlet port 247 is permitted and flow to the second outlet port 249 is blocked by a sealing surface 253 formed by a side 265 of the valve plug, the sealing surface extending along part of the circumference around the axis L of the valve plug. By rotating the valve plug 251 to the position shown in FIG. 4B, flow to the first outlet port 247 is blocked by the side 265 of the valve plug and flow to the second outlet port 249 is permitted. Unlike in the embodiments shown in FIGS. 2A1-2C2 and FIGS, 3A1-3C2, the sealing surface 253 of the valve plug 251 extending circumferentially around the axis L of the valve plug closes adjacent the valve seat 255 of the passage 243 by being rotated about the axis

L.

[0027] The EGR valve 37 shown in FIGS. 2A1-2C2 shall be referred to for purposes of discussion, it being understood that the discussion of the EGR valve of FIGS. 2A1-2C2 applies, as well, to the EGR valves 137 and 237 shown in FIGS. 3A1-3C2 and FIGS. 4A-4C. The EGR valve 37 is preferably a proportional control valve. The engine arrangement 21 comprises an actuator 73 (FIG. 1) of any suitable type, such as but not limited to electric, hydraulic, or pneumatic, that is connected to a valve stem of the valve and is adapted to position the valve plug 51 in any one of a plurality of positions between the first position and the second position.

In the valve 37 shown in FIGS. 2B1-2B2, the valve plug 51 is moved to a position between the first position and the second position so that flow to the first outlet port 47 is partially but not completely blocked, and flow to the second outlet port 49 is permitted. Similarly, in the valve shown in FIGS. 3C1-3C2, the valve plug 151 is moved to a position between the first position and the second position so that flow to the first outlet port 147 is partially but not completely blocked, and flow to the second outlet port 149 is permitted. Similarly, in the valve shown in

FIG. 4C, the valve plug 251 is moved to a position between the first position and the second position so that flow to the first outlet port 247 is partially but not completely blocked, and flow to the second outlet port 249 is permitted.

[0028] Referring again to the EGR valve 37 of FIGS. 2A1-2C2 for purposes of discussion, ordinarily, the valve plug 51 is configured so that progressively more exhaust gas flows through the passage 43 from the inlet port 45 to the second one 49 of the two outlet ports and progressively less exhaust gas flow is permitted to the first one 47 of the two ports as the valve plug is moved away from the first position (FIGS. 2A1-2A2) toward the second position (FIGS.

2C1-2C2).

[0029] As seen in FIG. 1, the engine arrangement 21 typically includes a turbocharger comprising a turbine 75 in the main exhaust line 31 and a compressor 77 in the intake line 27 upstream of the connection of the EGR line 39 to the intake line. The present invention facilitates avoiding the use of backpressure devices such as variable geometry turbines or exhaust pressure valves in the exhaust line to facilitate obtaining sufficient pressure in the EGR line to permit flow into the intake line because engine pumping alone can be sufficient to provide such pressure. As it opens a path to the EGR line, the EGR valve 37 simultaneously increasingly blocks the normal exhaust gas flow to the main exhaust line 31 and, thus, to the turbine 75, increasing pressure in the first exhaust line 35b. The valve is also useful in connection with, for example, fuel injector strategies such as a split late post (SLP) fuel injector strategy whereby fuel is combusted more fully in one or the other of the sets of cylinders 25a or 25b. For example, flow of exhaust from a set of cylinders where combustion is less complete can be through the second exhaust line 33 to the main exhaust line 31, and flow of exhaust gas from a set of cylinders where combustion is more complete can be through the first exhaust line to the EGR 37 valve and then to the EGR line 39, thereby reducing the risk of EGR cooler plugging and varnishing of other internal engine components. It is known that flowing unbumt hydrocarbons into EGR coolers and through turbo chargers can cause plugging and varnishing of these components thereby compromising their effectiveness. Thus, the turbocharger can be a fixed geometry turbocharger, permitting use of less expensive, less complex equipment in the engine arrangement. Nonetheless, a backpressure device such as a variable geometry turbine may be provided in the main exhaust line. Exhaust after-treatment equipment 79 can be provided, ordinarily downstream of the turbine 75,

[0030] A method for operating an engine arrangement 21 is described with reference to components of an EGR valve 37 shown in FIGS, 2A1-2C2, it being appreciated that the description also applies to the other embodiments of the EGR valve described herein. The method comprises operating the engine 23 so that exhaust gas from the second set 25a of the plurality of cylinders 25 is received in the second manifold portion 29a and flows to the main exhaust line 31 and exhaust gas from the first set 25b of the plurality of cylinders is received in the first manifold portion 29b and flows to the inlet port 45 of the EGR valve 37. The valve plug

51 is moved to the first position (FIGS. 2A1-2A2) so that substantially all of the exhaust gas from the first set 25b of the plurality of cylinders 25 flows to the main exhaust line 31. The valve plug 51 is moved from the first position toward the second position (FIGS. 2B1-2B2 and FIGS. 2C1-2C2) so that at least some of the exhaust gas from the first set 25b of the plurality of cylinders 25 flows into the EGR line 39. The method can comprise moving the valve plug 51 to the second position (FIGS. 2C1-2C2) so that the exhaust gas from the first set 25b of the plurality of cylinders 25 flows into the EGR line 39 and flow to the first outlet port 47 and the main exhaust line 31 is blocked or completely blocked.

[0031] In certain fuel injector strategies, fuel is combusted more fully or less fully. For example, fuel may be more fully combusted in the first set 25b of the plurality of cylinders than in the second set 25a of the plurality of cylinders by delaying fuel injection in the second set of the plurality of cylinders. Timing of fuel injection to individual cylinders can be controlled by a suitable known injector configuration and a controller, such as a conventional engine control unit

(ECU). When fuel is less fully combusted, the resulting exhaust gas may result in plugging an

EGR cooler (not shown) in the EGR line 39 and varnishing of other engine components.

[0032] According to an aspect of the present invention, when fuel in the second set 25a of cylinders and in the first set 25b of cylinders is combusted to substantially the same extent, the valve plug 51 can be held in the first position. When fuel is more fully combusted in the first set

25b of the plurality of cylinders than in the second set 25a of the plurality of cylinders, the valve plug 51 can be moved away from the first position toward the second position so that more fully combusted fuel is directed to the EGR line 39 and the possibility of plugging an EGR cooler or varnishing other components in the EGR line can be reduced. Of course, if fuel in the first set

25b of the plurality of cylinders 25 is less fully combusted than desired, it is also possible to reduce the possibility of plugging the EGR cooler or varnishing components in the EGR line 39 by moving the valve plug 51 to the first position. Further, the valve plug 51 can be held in a position between the first position and the second position while combusting fuel more fully (or less fully, as the case may be) in the first set of the plurality of cylinders than in the second set of cylinders.

[0033] In the present application, the use of terms such as “including" is open-ended and is intended to have the same meaning as terms such as “comprising” and not preclude the presence of other structure, material, or acts. Similarly, though the use of terms such as “can” or “may” is intended to be open-ended and to reflect that structure, material, or acts are not necessary, the failure to use such terms is not intended to reflect that structure, material, or acts are essential.

To the extent that structure, material, or acts are presently considered to be essential, they are identified as such.

[0034] While this invention has been illustrated and described in accordance with a preferred embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.

Claims

WHAT IS CLAIMED IS:

1. An engine arrangement, comprising: an internal combustion engine comprising a plurality of cylinders; an intake line arranged to deliver intake gas to the plurality of cylinders; an exhaust manifold comprising an exhaust manifold portion arranged to receive exhaust gas exiting the plurality of cylinders; a main exhaust line; an exhaust line connected at a first end to the exhaust manifold portion and at a second end to an exhaust gas recirculation (EGR) valve; an EGR line between the EGR valve and the intake line; and the EGR valve comprising a valve body having a passage comprising an inlet port connected to the exhaust line, two outlet ports, a first one of the two outlet ports being connected to the main exhaust line and a second one of the two outlet ports being connected to the EGR line, and a valve plug movable between a first position in which a sealing surface extending along at least part of a circumference around an axis of the valve plug closes adjacent a valve seat of the passage so that exhaust gas flows through the passage from the inlet port to the first one of the two outlet ports and exhaust gas flow to the second one of the two outlet ports is blocked and a second position in which exhaust gas flows through the passage from the inlet port to the second one of the two outlet ports and exhaust gas flow to the first one of the two ports is blocked by a side portion of the valve plug.

2. The engine arrangement as set forth in claim 1, wherein the sealing surface is seated against the valve seat when the valve plug is in the first position.

3. The engine arrangement as set forth in claim 2, wherein valve plug comprises a front portion, a rear portion, and a side portion between the front portion and the rear portion, the sealing surface comprising part of the side portion.

4. The engine arrangement as set forth in claim 3, wherein the side portion comprises a main body portion, the sealing surface comprises a first end furthest from the main body portion and a second end closest to the main body portion, the first end being disposed radially outward of the second end relative to a longitudinal axis of the valve plug.

5. The engine arrangement as set forth in claim 4, wherein the main body portion includes a recess extending from the second end of the sealing surface toward the longitudinal axis of the valve plug.

6. The engine arrangement as set forth in claim 1, wherein the EGR valve is a proportional control valve and the engine arrangement comprises an actuator adapted to position the valve plug in any one of a plurality of positions between the first position and the second position.

7. The engine arrangement as set forth in claim 6, wherein the valve plug is configured so that progressively more exhaust gas flows through the passage from the inlet port to the second one of the two outlet ports and progressively less exhaust gas flow is permitted to the first one of the two ports as the valve plug is moved away from the first position toward the second position.

8. The engine arrangement as set forth in claim 1 , comprising a turbocharger, the turbocharger comprising a turbine in the main exhaust line.

9. The engine arrangement as set forth in claim 8, wherein the turbocharger is a fixed geometry turbocharger.

10. The engine arrangement as set forth in claim 1 , comprising a backpressure device in the main exhaust line.

11. The engine arrangement as set forth in claim 1 , wherein the valve plug is movable axially between the first position and the second position.

12. The engine arrangement as set forth in claim 1, wherein the exhaust manifold comprises the exhaust manifold portion arranged to receive exhaust gas exiting a first set of the plurality of cylinders and a second exhaust manifold portion arranged to receive exhaust gas exiting a second set of the plurality of cylinders, and a second exhaust line connected at a first end to the second exhaust manifold portion and connected at a second end to the main exhaust line.

13. A valve assembly, comprising: a valve body having a passage comprising an inlet port and two outlet ports; and a valve plug movable between a first position in which a sealing surface extending along at least part of a circumference around an axis of the valve plug closes adjacent a valve seat of the passage and so that gas is adapted to flow through the passage from the inlet port to the first one of the two outlet ports and gas flow to the second one of the two outlet ports is blocked and a second position in which gas flows through the passage from the inlet port to the second one of the two outlet ports and gas flow to the first one of the two ports is blocked by a side portion of the valve plug.

14. The valve assembly as set forth in claim 13, wherein the sealing surface is seated against the valve seat when the valve plug is in the first position.

15. The valve assembly as set forth in claim 14, wherein valve plug comprises a front portion, a rear portion, and the side portion between the front portion and the rear portion, the sealing surface comprising part of the side portion.

16. The valve assembly as set forth in claim 15, wherein the side portion comprises a main body portion, the sealing surface comprises a first end furthest from the main body portion and a second end closest to the main body portion, the first end being disposed radially outward of the second end relative to a longitudinal axis of the valve plug.

17. The valve assembly as set forth in claim 16, wherein the main body portion includes a recess extending from the second end of the sealing surface toward the longitudinal axis of the valve plug.

18. The valve assembly as set forth in claim 13, wherein the valve plug is movable axially between the first position and the second position.

19. A method for operating an engine arrangement, the engine arrangement comprising an internal combustion engine comprising a plurality of cylinders; an intake line arranged to deliver intake gas to the plurality of cylinders; an exhaust manifold comprising an exhaust manifold portion arranged to receive exhaust gas exiting the plurality of cylinders; a main exhaust line; an exhaust line connected at a first end to the exhaust manifold portion and at a second end to an exhaust gas recirculation (EGR) valve; an EGR line between the EGR valve and the intake line; and the EGR valve comprising a valve body having a passage comprising an inlet port connected to the exhaust line, two outlet ports, a first one of the two outlet ports being connected to the main exhaust line and a second one of the two outlet ports being connected to the EGR line, and a valve plug movable between a first position in which a sealing surface extending along at least part of a circumference around an axis of the valve plug closes adjacent a valve seat of the passage and so that exhaust gas flows through the passage from the inlet port to the first one of the two outlet ports and exhaust gas flow to the second one of the two outlet ports is blocked and a second position in which exhaust gas flows through the passage from the inlet port to the second one of the two outlet ports and exhaust gas flow to the first one of the two ports is blocked by a side portion of the valve plug, the method comprising: operating the engine so that exhaust gas from the plurality of cylinders is received in the manifold portion and flows to the inlet port; moving the valve plug to the first position so that substantially all of the exhaust gas from the plurality of cylinders flows to the main exhaust line; and moving the valve plug from the first position toward the second position so that at least some of the exhaust gas from the plurality of cylinders flows into the EGR line.

20. The method for operating the engine arrangement as set forth in claim 19, comprising moving the valve plug to the second position so that substantially all of the exhaust gas from the plurality of cylinders flows into the EGR line.

21. The method for operating the engine arrangement as set forth in claim 19, wherein the exhaust manifold portion is arranged to receive exhaust gas exiting a first set of the plurality of cylinders, the exhaust manifold comprises a second exhaust manifold portion arranged to receive exhaust gas exiting a second set of the plurality of cylinders, and the engine arrangement comprises a second exhaust line connected at a first end to the second exhaust manifold portion and connected at a second end to the main exhaust line, the method comprising operating the engine so that exhaust gas from the first set of the plurality of cylinders is received in the first manifold portion and flows to the inlet port and exhaust gas from the second set of the plurality of cylinders is received in the second manifold portion and flows to the main exhaust line, holding the valve plug in the first position and combusting fuel in the first set of the plurality of cylinders and in the second set of the plurality of cylinders to substantially a same extent, and moving the valve plug away from the first position toward the second position and combusting fuel more fully in the first set of the plurality of cylinders than in the second set of the plurality of cylinders.

22. The method for operating the engine arrangement as set forth in claim 21, comprising combusting fuel more fully in the first set of the plurality of cylinders than in the second set of the plurality of cylinders by delaying fuel injection in the first set of the plurality of cylinders.

23. The method for operating the engine arrangement as set forth in claim 21, comprising holding the valve plug in a position between the first position and the second position while combusting fuel more fully in the first set of the plurality of cylinders than in the second set of the plurality of cylinders.

24. The method for operating the engine arrangement as set forth in claim 19, wherein the valve plug is moved axially between the first position and the second position.