Patent Application
20140331947
This disclosure relates to cooling an internal combustion engine having a cylinder block with Siamese cylinders.
Internal combustion engines include cooling systems for removing excess heat that is produced from the combustion of fuel and friction of moving components. Removal of the excess heat is necessary to prevent the mechanical failure of engine components. The cooling systems typically include a liquid coolant that is pumped through passageways (sometimes known as water jackets) in the engine block, cylinder head, and other engine components. Heat is transferred to the liquid coolant from the engine components when the coolant flows through the various passageways in the engine components. Heat is then transferred from the liquid coolant to the surrounding environment through a heat exchanger, such as radiator. Once the heat is transferred to the surrounding environment, the liquid coolant is redirected through the passageways in the engine components and the process is repeated.
An internal combustion engine having cylinders that share a common wall is known as a “Siamese design” and the common wall is known as the “bore bridge.” The bore bridge will experience high temperatures because it is in close proximity to the two combustion chambers of the adjacent cylinders, and to the two sets of piston rings that transfer heat to the cylinder block. Packaging of a cooling system in the area of the bore bridge is also difficult adding to the increased temperature of the region.
Various efforts have been made to cool the bore bridge. It is known to drill cooling channels within the bore bridge that extend between the water jacket in the engine block and the cylinder head. This configuration presents limitations in the flow of the liquid coolant through channels in the bore bridge because of a limited pressure differential and channel cross sectional area.
It would be desirable to provide a cooling channel in the bore bridge that has an adequate pressure differential and flow area to allow liquid coolant to sufficiently flow through the channel.
In at least one embodiment, an engine is provided having an open deck cylinder block that has a deck with an open water jacket that surrounds a number cylinders, and has a Siamese design where the cylinders share a common wall known as the bore bridge. The bore bridge includes a cooling channel that is open to the deck and extends across the bore bridge from the water jacket on one side of the cylinder to an end point short of the water jacket on the other side. A cylinder head gasket has a bottom surface that is disposed of on the deck of the cylinder block, and a cylinder head has a face surface that is disposed of on a top surface of the cylinder head gasket. The cooling channel cooperates with water jacket to enable coolant to flow from the water jacket to an inlet port in the cylinder head, the inlet port being located proximate to the end point of cooling channel.
In at least one additional embodiment, an open deck cylinder block is provided. The open deck cylinder block has an open water jacket that surrounds the cylinders and has a Siamese design where the cylinders share a common wall known as the bore bridge. The bore bridge includes a cooling channel that is open to the deck and extends across the bore bridge from the water jacket on one side of the cylinder to an end point short of the water jacket on the other side.
In at least one additional embodiment, a cylinder head gasket for use in an engine having an engine block with an open deck Siamese cylinder design is provided. The generally planar gasket body has an upper surface that cooperates with cylinder head and a lower surface that cooperates with a deck surface of an engine block. The cylinder head gasket has an inlet port in the lower surface that is open to the water jacket in the cylinder block and is adjacent to one side of a cylinder bore bridge that is formed between two Siamesed cylinders. An outlet port is formed in the upper surface of the cylinder head gasket and is adjacent to an opposite side of the cylinder bore bridge and open to a cylinder head coolant passageway. The outlet port is also sealed from the water jacket on the opposite side of the cylinder bore bridge. A first elongate cooling channel in the cylinder head gasket extends between the inlet and outlet ports for overlying and open to a second elongate cooling channel in the cylinder bore bridge, which enables coolant to flow from the water jacket on one side of the cylinder bore bridge, across the cylinder bore bridge, to the cylinder head coolant passageway on the opposite side of a cylinder bridge. The first elongate channel flares out at the outlet port to maintain a minimum summed cross sectional flow area of the first and second channels as a cross sectional flow area of the second elongate channel decreases.
a is an exploded isometric view of the engine;
b is an alternative embodiment of the cylinder head gasket;
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
An exploded view of an internal combustion engine 10 according the present disclosure is illustrated in
a and 2 show the cylinder block 12 having four cylinders 26 with a Siamese design, where the adjacent cylinders 26 share a common wall known as the bore bridge 28. The deck surface 20 of the cylinder block 12 is open to a water jacket 30 that surrounds the cylinders 26. Cooling channels 32 located on the cylinder bore bridges 28 extend a length L from the water jacket 30 on one side of the bore bridge 28 to end points 34 short of the water jacket 30 on the other side of the bore bridge 28.
Still referring to
Referring to
Referring to
The cylinder head gasket 114 includes cooling channels 126. The cooling channels include inlet ports 128 that cooperate with the water jacket 30 of the cylinder block 12 allowing coolant to flow from the water jacket 30 into the cooling channels, and outlet ports 130 that cooperate with the cooling passageway 138 in the cylinder head 116, allowing coolant to flow from the cooling channels 126 into the cooling passageway 138. Between the water jacket 30 of the cylinder block 12 and the cooling passageway 138 in the cylinder head 116, the cooling channels 126 are open to and adjacent to the cooling channels 32 located on the cylinder bore bridge 28. At the outlet port 130, the cooling channel 126 includes a step 132 that creates a seal between the cooling channel 126 and the water jacket 30 on the other side of the bore bridge 28.
Referring to
Referring to
Referring to
Although the preferred embodiments described above were directed to open deck cylinder blocks, the invention should not be construed as limited to open deck cylinder blocks and should include both open and closed deck cylinder blocks.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
