Engine block including an integrated flow channel

A cast-aluminum engine block for a compression-ignition internal combustion engine includes a plurality of cylinders that are disposed in an in-line arrangement. The engine block includes a top portion including a top deck and a bottom portion including a plurality of main bearings that are disposed to support journals of a crankshaft. An integrated flow channel is formed between the second end and the last cylinder and proximal to the top deck, and is a continuous channel that passes from the first side to the second side through the portion of the engine block between the second end and the last cylinder and proximal to the top deck. A coolant passageway is disposed in the engine block between the integrated flow channel and the last cylinder, and is oriented parallel to the elevation axis.

INTRODUCTION

An internal combustion engine is composed of an engine block that provides a structure for reciprocating pistons and a crankshaft, a cylinder head that manages intake air and exhaust flow to the pistons, an intake air manifold, an exhaust manifold, and a crankcase. The engine block also provides structure for coupling a geartrain to an end of the crankshaft to transfer generated mechanical power.

SUMMARY

An engine block for a compression-ignition internal combustion engine is described, and includes a cast-aluminum engine block having a first end and a second end in relation to a longitudinal axis, and a first side and a second side in relation to a transverse axis. The engine block includes a plurality of sleeved cylinder barrels that define a plurality of cylinders that are disposed in an in-line arrangement along the longitudinal axis, and a last cylinder is defined as being the one of the cylinder barrels that is disposed proximal to the second end. The engine block includes a top portion including a top deck and a bottom portion including a plurality of main bearings that are disposed to support journals of a crankshaft, wherein the top and bottom portions are in relation to an elevation axis. The engine block includes a transmission flange that is disposed at the second end. An integrated flow channel is formed within a portion of the engine block between the second end and the last cylinder and proximal to the top deck. The integrated flow channel is a continuous channel that is aligned with the transverse axis and is disposed to pass from the first side to the second side through the portion of the engine block between the second end and the last cylinder and proximal to the top deck. A coolant passageway is disposed in the engine block between the integrated flow channel and the last cylinder, and is oriented parallel to the elevation axis.

An aspect of the disclosure includes the cast-aluminum engine block being formed via a precision sand casting process.

Another aspect of the disclosure includes the top deck being disposed to accommodate a cylinder head.

Another aspect of the disclosure includes a slip-fit cylinder liner sleeve composed from iron being inserted into each of the cylinder barrels.

Another aspect of the disclosure includes the cylinder barrels being disposed to receive pistons.

Another aspect of the disclosure includes a plurality of air insulation pockets being formed in the engine block that are annular to the last cylinder.

Another aspect of the disclosure includes the integrated flow channel having a rounded rectangular cross-sectional shape.

Another aspect of the disclosure includes the integrated flow channel having an irregular concave polygonal cross-sectional shape

Another aspect of the disclosure includes a portion of an inner surface area of the integrated flow channel that is adjacent to the portion of the cylinder block that forms the last cylinder being minimized.

Another aspect of the disclosure includes a first flange mount being disposed on the first side of the engine block at a first end of the integrated flow channel, and a second flange mount being disposed on the second side of the engine block at a second end of the integrated flow channel.

Another aspect of the disclosure includes an internal combustion engine that includes a cylinder head fluidly coupled to an air intake manifold and an exhaust manifold and an exhaust gas recirculation valve that is disposed to regulate the flow of exhaust gas from the exhaust manifold to the air intake manifold, wherein the cylinder head is disposed on an engine block. The engine block is a cast-aluminum engine block having a first end and a second end in relation to a longitudinal axis, and a first side and a second side in relation to a transverse axis. The engine block includes a plurality of sleeved cylinder barrels defining a plurality of cylinders that are disposed in an in-line arrangement along the longitudinal axis, wherein a last cylinder is defined as being the one of the cylinder barrels that is disposed proximal to the second end. The engine block also has a top portion including a top deck and a bottom portion including a plurality of main bearings that are disposed to support journals of a crankshaft, wherein the top and bottom portions are in relation to an elevation axis and the cylinder head is disposed on the top deck. The engine block also includes a transmission flange disposed at the second end. An integrated flow channel is formed within a portion of the engine block between the second end and the last cylinder and proximal to the top deck, wherein the integrated flow channel is a continuous channel that is aligned with the transverse axis and is disposed to pass from the first side to the second side through the portion of the engine block between the second end and the last cylinder and proximal to the top deck. A coolant passageway is interposed in the engine block between the integrated flow channel and the last cylinder. The integrated flow channel is fluidly coupled between the exhaust manifold and the exhaust gas recirculation valve.

It should be understood that the appended drawings are not necessarily to scale, and present a somewhat simplified representation of various preferred features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes. Details associated with such features will be determined in part by the particular intended application and use environment.

DETAILED DESCRIPTION

The components of the disclosed embodiments, as described and illustrated herein, may be arranged and designed in a variety of different configurations. Thus, the following detailed description is not intended to limit the scope of the disclosure, as claimed, but is merely representative of possible embodiments thereof. In addition, while numerous specific details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed herein, some embodiments can be practiced without some or all of these details. Moreover, for the purpose of clarity, certain technical material that is known in the related art has not been described in detail in order to avoid unnecessarily obscuring the disclosure. Furthermore, the drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms such as top, bottom, left, right, up, over, above, below, beneath, rear, and front, may be used with respect to the drawings. These and similar directional terms are not to be construed to limit the scope of the disclosure. Furthermore, the disclosure, as illustrated and described herein, may be practiced in the absence of an element that is not specifically disclosed herein. As employed herein, the term “upstream” and related terms refer to elements that are towards an origination of a flow stream relative to an indicated location, and the term “downstream” and related terms refer to elements that are away from an origination of a flow stream relative to an indicated location.

Referring to the drawings, wherein like reference numerals correspond to like or similar components throughout the several Figures,FIGS. 1-4, consistent with embodiments disclosed herein, schematically illustrate various perspectives of an engine block10that is a portion of an internal combustion engine. The internal combustion engine may be disposed in a vehicle that may include, but not be limited to a mobile platform in the form of a commercial vehicle, industrial vehicle, agricultural vehicle, passenger vehicle, aircraft, watercraft, train, all-terrain vehicle, personal movement apparatus, robot and the like to accomplish the purposes of this disclosure.

The internal combustion engine includes an air intake system, an exhaust system, and an exhaust gas recirculation (EGR) system (not shown). The EGR system is composed of conduits and a controllable EGR valve that are arranged to controllably channel a portion of engine exhaust gas into the air intake system, wherein the recirculated exhaust gas mixes with intake air. Expected performance benefits from the introduction of the recirculated exhaust gas into the intake air may include a reduction in combustion temperatures, which may result in improved exhaust emissions. As set forth in detail herein, one of the conduits of the EGR system can be advantageously configured as an integrated flow channel40that is formed within a portion of the block casting of the engine block10. The integrated flow channel40is preferably integrated into an EGR system that is employed to control flow of recirculated exhaust gases into an air intake system of the engine, in conjunction with other conduits and an EGR valve. One embodiment of an internal combustion engine with an EGR system is described and schematically depicted with reference toFIG. 5.

Referring now toFIG. 1, the engine block10for the internal combustion engine is preferably configured for compression-ignition operation, e.g., a diesel engine. The engine block10is also configured to be adaptable to either a transverse mounting arrangement or a longitudinal mounting arrangement. The engine block10is also configured to be adaptable to an internal combustion engine that is designed to provide high performance and also be adaptable to an internal combustion engine that is designed to provide high efficiency. The description of the engine block10is provided in context of a three-dimensional coordinate system that includes a longitudinal axis13, a transverse axis15and an elevation axis17. The engine block10is preferably fabricated from an aluminum alloy that is formed by a precision sand casting process in one embodiment, or another suitable aluminum casting technique, such as a high pressure die cast process, a low pressure die cast process or a gravity die cast process.

The engine block10includes a first end12and a second end14that are defined in relation to the longitudinal axis13, a first side16and a second side18that are defined in relation to the transverse axis15, and a top portion32and a bottom portion36that are defined in relation to the elevation axis17. As described herein, the first end12is associated with a front portion of the internal combustion engine, and the second end14is associated with a rear portion of the internal combustion engine. Although not illustrated herein, the first end12can be designed to mount or otherwise accommodate air conditioning compressors, cooling fans, alternators, and other components that can be driven by pulley(s) that couple to an engine crankshaft. The second end14can be designed to include a transmission flange30. As described herein, the first side16is associated with engine exhaust and the second side18is associated with air intake. As described herein, the top portion32includes a top deck34that provides mounting structure for a cylinder head49and the bottom portion36includes a bottom deck38that provides a mounting structure that includes a plurality of main bearings that are disposed to support journals for the engine crankshaft (not shown).

The engine block10includes a plurality of cylinders20that are arranged in an in-line configuration along the longitudinal axis13. As shown, the engine block10is arranged to include four cylinders20that are arranged along the longitudinal axis13from the first end12to the second end14, including a first cylinder21, a second cylinder22, a third cylinder23and a fourth cylinder24. The quantity of the cylinders20is illustrative, and other quantities of the cylinders20may be employed within the scope of this disclosure. Each of the cylinders20includes a cylinder barrel that has been formed from aluminum as an integral part of the engine block10, with a sleeved liner26being inserted therein. In one embodiment, the sleeved liners26are slip-fit type liners that are inserted and thermally fit therein. In one embodiment, the sleeved liners26are fabricated from iron. Other suitable embodiments of sleeved liners26may include machined-OD (Outside Diameter) liners, cast-OD liners, or hybrid liners. One of the cylinders20is identified as a last cylinder25, which is defined as the one of the cylinders20that is disposed proximal to the second end14near the transmission flange30. In this embodiment, the fourth cylinder24is defined as the last cylinder25.

The engine block10includes the integrated flow channel40that is part of the block casting and is formed within a portion of the engine block10that is between the second end14and the last cylinder25, and is proximal to the top deck34. The integrated flow channel40is a continuous channel that is aligned with the transverse axis15and has a rounded rectangular cross-sectional shape in one embodiment. Alternatively, the integrated flow channel40may have a suitable cross-sectional shape, including, e.g., a round shape, an oval shape, or an irregular shape, such as an irregular concave polygonal cross-sectional shape, wherein at least one of the interior angles thereof is greater than 180 degrees. One example of an irregular concave polygonal cross-sectional shape is an L-shape. In one embodiment, the integrated flow channel40has a cross-sectional area that is specified to accommodate an expected magnitude of flow of the recirculated exhaust gas. The integrated flow channel40is formed in the engine block10to minimize the portion of the inner surface area thereof that is proximal to the last cylinder25while fitting within an outer envelope of the engine block10. In one embodiment, the integrated flow channel40is designed to accommodate an exhaust gas flowrate of a known maximum flowrate at an exhaust gas temperature of 500 C and a pressure of 2 bar. The integrated flow channel40is disposed to pass from the first side16to the second side18through the portion of the engine block10that is between the second end14and the last cylinder25and proximal to the top deck34. The integrated flow channel40includes a first end41, which is on the first, exhaust side16of the engine block10, and a second end43, which is on the second, intake side18of the engine block10. An exhaust flange attachment portion42is formed on the outside of the engine block10at the first end41of the integrated flow channel40. An EGR (“exhaust gas recirculation”) valve attachment portion44is formed on the outside of the engine block10at the second end43of the integrated flow channel40.

FIG. 2schematically shows a top-plan view perspective of a portion of the engine block10that is described with reference toFIG. 1, including the second end14and a portion of the last cylinder25, including the top deck34. Elements include the integrated flow channel40, a coolant jacket45including a coolant passageway46, air pockets48and head-to-block orientation/mounting apertures47.FIGS. 3 and 4schematically show side-plan cutaway perspectives of portions of the engine block10and an associated cylinder head49. This includesFIG. 3, which is a side-plan cutaway perspective of a portion of the engine block10shown at3-3, as indicated onFIG. 2, andFIG. 4, which is a side-plan cutaway perspective of a portion of the engine block10shown at4-4.

The coolant jacket45is part of an engine cooling system (not shown) that preferably includes an engine coolant pump, a radiator, a heater core, a thermostat, and related pipes, fittings and couplings that are arranged in a closed continuous circuit. The engine cooling circuit is designed and operated to manage heat transfer in the internal combustion engine, with most of the heat being generated by combustion.

The locations and orientations of the integrated flow channel40, the coolant passageway46and air pockets48in relation to the last cylinder25are advantageously selected to effect heat transfer. The coolant passageway46is disposed in parallel with the elevation axis17, and is arranged to permit coolant flow between the cylinder head49and the coolant jacket45of the engine block10. It is appreciated that there are other coolant passages in the engine cooling system that are arranged to permit coolant flow between the cylinder head49and the coolant jacket45of the engine block10. In one non-limiting embodiment, the other, non-illustrated coolant passages are arranged to permit coolant flow into the cylinder head49, and the coolant passageway46is arranged as a return line from the cylinder head49to the coolant jacket45.

As viewed from the top-plan view perspective that is illustrated with reference toFIG. 2, the coolant passageway46is interposed between the integrated flow channel40and the last cylinder25. In one embodiment, the minimum longitudinal distance between the integrated flow channel40and the sleeved liner26of the last cylinder25is 30 mm, as measured along the longitudinal axis13, with the interposed coolant passageway46having a cross-sectional distance of 15 mm. As such, at least 50% of the longitudinal distance between the integrated flow channel40and the sleeved liner26is composed of coolant that is flowing in the coolant passageway46. Furthermore, the air pockets48are interposed between the sleeved liner26and the integrated flow channel40. Thus, the interposed coolant passageway46and the air pockets48thermally decouple the sleeved liner26of the last cylinder25from the integrated flow channel40, interrupting much of the conductive heat transfer therebetween.

The thermal contributors of this configuration include the following elements. The combustion process generates heat in the last cylinder25that can be propagated through the sleeved liner26and the engine block10. The coolant being circulated can transfer heat through the engine cooling system including the coolant jacket45and the coolant passageway46. The exhaust gas includes heat, including heat in the recirculated exhaust gas that flows through the integrated flow channel40to the EGR valve and intake air system. The air pockets48also contribute to heat transfer via conductive heat transfer to the ambient air. During engine operation following a cold-start event, heat from the exhaust gas in the integrated flow channel40can be transferred to the coolant in the coolant passageway46, thus reducing the time to effect engine warmup. Other engine operating conditions can include, for example, high-load conditions, high ambient temperatures, steady-state load/speed conditions, etc.

FIGS. 3 and 4schematically show side-plan cutaway perspectives of portions of the engine block10and the cylinder head49. In one embodiment, and as shown, the integrated flow channel40has a rounded rectangular cross-sectional shape wherein a major axis of its rectangular cross-sectional shape is parallel with the elevation axis17.

FIG. 5schematically shows an internal combustion engine100including an exhaust gas recirculation system that is configured to incorporate the integrated flow channel40described with reference toFIGS. 1-4. The internal combustion engine100includes the engine block10having the integrated flow channel40, the cylinder head49, an intake manifold70, an exhaust manifold74, and an EGR valve72. The intake manifold70is fluidly coupled to the intake side of the cylinder head49at each of the cylinders21,22,23,24, and the exhaust manifold74is fluidly coupled to the exhaust side of the cylinder head49at each of the cylinders21,22,23,24. The integrated flow channel40is disposed at the second end14of the engine block10. The exhaust manifold74is fluidly coupled to an exhaust aftertreatment system via an exhaust pipe76. The integrated flow channel40is fluidly coupled to the exhaust manifold74via an exhaust-side pipe73, and fluidly coupled to an inlet side of the EGR valve72via an intake side pipe71. An outlet side of the EGR valve72is fluidly coupled the intake manifold70. The EGR valve72is in communication with a controller80, which controls its operation in response to engine and other operating conditions. Exhaust gas is indicated by arrows77, and intake air is indicated by arrows75.

The term “controller” and related terms such as control module, module, control, control unit, processor and similar terms refer to one or various combinations of Application Specific Integrated Circuit(s) (ASIC), electronic circuit(s), central processing unit(s), e.g., microprocessor(s) and associated non-transitory memory component(s) in the form of memory and storage devices (read only, programmable read only, random access, hard drive, etc.). The non-transitory memory component is capable of storing machine readable instructions in the form of one or more software or firmware programs or routines, combinational logic circuit(s), input/output circuit(s) and devices, signal conditioning and buffer circuitry and other components that can be accessed by one or more processors to provide a described functionality. Input/output circuit(s) and devices include analog/digital converters and related devices that monitor inputs from sensors, with such inputs monitored at a preset sampling frequency or in response to a triggering event. Software, firmware, programs, instructions, control routines, code, algorithms and similar terms mean controller-executable instruction sets including calibrations and look-up tables. Each controller executes control routine(s) to provide desired functions. Communication between controllers, and communication between controllers, actuators and/or sensors may be accomplished using a direct wired point-to-point link, a networked communication bus link, a wireless link or another suitable communication link, and is indicated by line82. Communication includes exchanging data signals in suitable form, including, for example, electrical signals via a conductive medium, electromagnetic signals via air, optical signals via optical waveguides, and the like. The data signals may include discrete, analog or digitized analog signals representing inputs from sensors, actuator commands, and communication between controllers. The term “signal” refers to a physically discernible indicator that conveys information, and may be a suitable waveform (e.g., electrical, optical, magnetic, mechanical or electromagnetic), such as DC, AC, sinusoidal-wave, triangular-wave, square-wave, vibration, and the like, that is capable of traveling through a medium.