The disclosure generally relates to a cylinder head for an internal combustion engine.
Internal combustion engines include a cylinder head, which covers one or more cylinder bores of an engine block. The cylinder head defines an inlet port, through which a mixture of fuel and air is introduced into the cylinder bore. The cylinder head moveably supports an inlet valve, which operates to open and close the inlet port during the operating cycle of the engine. A sharp change in direction of the inlet port, particularly at the inlet valve seat and exit of the inlet port into the cylinder bore, may disrupt or introduce turbulence into the flow of the fuel/air mixture.
A cylinder head for an internal combustion engine is provided. The cylinder head includes a structure, which defines an inlet port. The inlet port includes an exit. A seat cut surface is disposed adjacent the exit of the inlet port. The inlet port extends along a centerline. A cross section of the inlet port parallel to the centerline defines a long turn edge of the inlet port cross section, and an opposing sharp turn edge of the inlet port cross section. The long turn edge of the inlet port cross section defines a flow path trajectory that is substantially tangent with the long turn edge of the inlet port cross section at the exit of the inlet port. The flow path trajectory projects to an intersection with a bore axis that forms an acute, interior angle that is greater than 30°. The seat cut surface and the flow path trajectory are substantially aligned to extend the flow path trajectory of the long turn edge of the inlet port cross section across the seat cut surface.
An internal combustion engine is also provided. The internal combustion engine includes a block that defines at least one cylinder bore extending along a bore axis. A cylinder head is attached to the block. The cylinder head includes an inlet port having an exit. The inlet port is operable to introduce a mixture of fuel and air into the cylinder bore. The cylinder head includes a throat cut surface at the exit of the inlet port. An inlet valve is moveably supported by the cylinder head. The inlet valve includes a seat. A valve seat insert is coupled to the structure. The valve seat insert is disposed around a periphery of the exit of the inlet port. The valve seat insert defines a seat cut surface disposed adjacent the throat cut surface at the exit of the inlet port. The seat cut surface and the seat of the inlet valve are shaped to engage each other in sealing engagement for sealing the exit of the inlet port. The inlet port extends along a centerline. A cross section of the inlet port along a plane defined by the centerline of the inlet port and the bore axis defines a long turn edge of the inlet port cross section, and an opposing sharp turn edge of the inlet port cross section. The long turn edge of the inlet port cross section defines a flow path trajectory that is substantially tangent with the long turn edge of the inlet port cross section at the exit of the inlet port. The flow path trajectory projects to an intersection with the bore axis that forms an acute, interior angle that is greater than 30°. The seat cut surface and the throat cut surface are substantially aligned with the flow path trajectory to extend the flow path trajectory of the long turn edge of the inlet port cross section across both the throat cut surface and the seat cut surface.
Accordingly, because the seat cut surface and the throat cut surface are generally aligned with the flow path trajectory defined by the inlet port, the flow of the fuel/air mixture is not disrupted as the fuel/air mixture passes across the seat cut surface and into the cylinder bore, thereby reducing turbulence in the flow of the fuel/air mixture and improving performance of the internal combustion engine. The seat cut surface is generally aligned with the throat cut surface to substantially extend the flow path trajectory of the inlet port without interference and/or disruption.
The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the best modes for carrying out the teachings when taken in connection with the accompanying drawings.
Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” “top,” “bottom,” etc., are used descriptively for the figures, and do not represent limitations on the scope of the disclosure, as defined by the appended claims. Furthermore, the teachings may be described herein in terms of functional and/or logical block components and/or various processing steps. It should be realized that such block components may be comprised of any number of hardware, software, and/or firmware components configured to perform the specified functions.
Referring to the Figures, wherein like numerals indicate like parts throughout the several views, an internal combustion engine is generally shown at 20. The internal combustion engine 20 may include any style and/or configuration of engine. For example, the internal combustion engine 20 may include, but is not limited to, a gasoline engine or a diesel engine. Additionally, the internal combustion engine 20 may be configured as, but is not limited to, an inline motor or a V-style motor.
Referring to
The cylinder head 28 includes a structure 30. The structure 30 defines at least one inlet port 32 and at least one exhaust port (not shown) per cylinder bore 24. The inlet port 32 includes an exit 34 disposed adjacent the cylinder bore 24. The inlet port 32 is operable to introduce or direct a mixture of fuel and air, forming the combustion charge, into the cylinder bore 24. The cylinder head 28 includes a throat cut surface 36 disposed at the exit 34 of the inlet port 32. The throat cut surface 36 is defined by the structure 30, and partially defines the inlet port 32, adjacent the exit 34 of the inlet port 32.
A valve seat insert 38 is coupled to the structure 30. The valve seat insert 38 is disposed around a periphery or circumference of the exit 34 of the inlet port 32. The valve seat insert 38 may be coupled to the structure 30 in any suitable manner, such as but not limited to a press fit connection. The intersection or joint between the inlet port 32 and the valve seat 44 defines the exit 34 of the inlet port 32. The valve seat insert 38 is formed to define a seat cut surface 40. The seat cut surface 40 is disposed adjacent the throat cut surface 36, at the exit 34 of the inlet port 32. Accordingly, the seat cut surface 40 is disposed adjacent the exit 34 of the inlet port 32, downstream of the throat cut surface 36 of the inlet port 32.
The internal combustion engine 20 includes at least one inlet valve 42 for each inlet port 32. The inlet valve 42 is moveably supported by the cylinder head 28. The inlet valve 42 includes and/or defines a seat 44. The seat cut surface 40 and the seat 44 of the inlet valve 42 are shaped to engage each other in sealing engagement for sealing the exit 34 of the inlet port 32. As is known, the inlet valve 42 moves in a reciprocating motion to open and close fluid communication between the inlet port 32 and the cylinder bore 24, during the operation of the engine cycle.
The inlet port 32 extends along a centerline 46, between an entrance (not shown) and the exit 34. It should be appreciated that the centerline 46 of the inlet port 32 may be a curvilinear, and is generally defined as the three dimensional center of the inlet port 32, extending between the entrance and the exit 34. A cross section of the inlet port 32, shown in
The long turn edge 48 of the inlet port 32 cross section defines a flow path trajectory 52. The flow path trajectory 52 is the flow path that the air/fuel mixture follows along the long turn edge 48 of the inlet port 32 cross section as the air/fuel mixture flows through the inlet port 32 and nears the exit 34 of the inlet port 32. The flow path trajectory 52 is substantially tangent with the long turn edge 48 of the inlet port 32 cross section at the exit 34 of the inlet port 32. Referring to
The throat cut surface 36 and the seat cut surface 40 are substantially aligned with each other around the perimeter or circumference of the exit 34 of the inlet port 32. By shaping the seat cut surface 40 and the throat cut surface 36 to align with each other, the throat cut surface 36 is substantially an extension of the seat cut surface 40 into the inlet port 32. Stated in reverse, the seat cut surface 40 is substantially an extension of the throat cut surface 36 from the inlet port 32, and into the cylinder bore 24.
Referring to
The seat cut surface 40 and the throat cut surface 36 are also substantially aligned with the flow path trajectory 52. The seat cut surface 40 is aligned with the flow path trajectory 52 to extend the flow path trajectory 52 of the long turn edge 48 of the inlet port 32 cross section across both the throat cut surface 36 and the seat cut surface 40, so that the inlet port 32 does not disrupt or introduce turbulence into the flow of the fuel/air mixture as the fuel/air mixture is introduced into the cylinder bore 24.
As described herein, the seat cut surface 40 and the flow path trajectory 52 are substantially aligned with each other when an angular difference between the flow path trajectory 52 and the seat cut surface 40 relative to the bore axis 26 is between 0° and 10°, and more preferably, between 0° and 5°. Similarly, as described herein, the throat cut surface 36 and the flow path trajectory 52 are substantially aligned with each other when an angular difference between the flow path trajectory 52 and the throat cut surface 36 relative to the bore axis 26 is between 0° and 10°, and more preferably, between 0° and 5°.
For example, with reference to
The detailed description and the drawings or figures are supportive and descriptive of the disclosure, but the scope of the disclosure is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed teachings have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims.