Patent Application
20120006295
The present disclosure relates to an engine assembly, and more specifically to an engine cylinder with an asymmetric valve configuration.
This section provides background information related to the present disclosure which is not necessarily prior art.
An engine assembly may include an engine block that defines a plurality of cylinders. Each cylinder may be in communication with a fuel system, an intake manifold through at least one intake valve and an exhaust manifold through at least one exhaust valve. The size of the intake and exhaust valves, among other factors, affects engine operation. As the size of a cylinder bore becomes smaller, however, the size of each of the valves may also become correspondingly smaller. Thus, the valve size of a smaller bore engine may be limited by the space available within a cylinder.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
An engine assembly may include an engine structure, a first valve and a second valve. The engine structure may define a combustion chamber and first and second exhaust ports in communication with the combustion chamber. The first valve may be arranged within the first exhaust port and have a first surface area. The second valve may be arranged within the second exhaust port and have a second surface area greater than the first surface area.
A cylinder head may include a combustion chamber surface that defines a first exhaust port and a second exhaust port. The first exhaust port may have a first cross-sectional area and the second exhaust port may have a second cross-sectional area greater than the first cross-sectional area.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Examples of the present disclosure will now be described more fully with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
When an element or layer is referred to as being “on,” “engaged to,” “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Referring to
The fuel system 14 may include a fuel pump 22, a fuel tank 24, a fuel rail 26, fuel injectors 28, a main fuel supply line 30, secondary fuel supply lines 32 and fuel return lines 34. The fuel pump 22 may be in communication with the fuel tank 24 and may provide a pressurized fuel supply to the fuel rail 26 via the main fuel supply line 30. The fuel rail 26 may provide the pressurized fuel to injectors 28 via the secondary fuel supply lines 32. The fuel rail 26 may include a pressure regulating valve 36 that regulates fuel pressure within the fuel rail 26 by returning excess fuel to the fuel tank 24 via a return line 38.
The fuel injectors 28 may each include an actuation assembly 40 in communication with the control module 16. In the present non-limiting example, the fuel injectors 28 may form direct injection fuel injectors where fuel is injected directly into the cylinders 20. The fuel injectors 28 may return excess fuel to the fuel tank 24 via the fuel return lines 34.
With additional reference to
The pistons 42 may be disposed within the combustion chambers 60. The cylinder head 54, the engine block 56 and the pistons 42 may cooperate to define combustion chambers 60. The cylinder head 54 may include a combustion chamber surface 55 that defines at least one intake port 62 and at least one exhaust port 64 for each combustion chamber 60. The intake valve(s) 50 may open and close the intake port(s) 62 and the exhaust valve(s) 52 may open and close the exhaust port(s) 64. The valve lift assemblies 48 may be engaged with the intake camshaft assembly 44 and the intake valve(s) 50 to open the intake port(s) 62. Further, the valve lift assemblies 44 may be engaged with the exhaust camshaft assembly 46 and the exhaust valve(s) 52 to open the exhaust port(s) 64.
Referring to
Each of the valves 110A-D may have a corresponding surface area and diameter (first valve 110A may have a first surface area Av1 and a first diameter Dv1, second valve 110B may have a second surface area Av2 and a second diameter Dv2, third valve 110C may have a third surface area Av3 and a third diameter Dv3, fourth valve 110D may have a fourth surface area Av4 and a fourth diameter Dv4). Similarly, each of the ports 112A-D may have a corresponding cross-sectional area and diameter (first port 112A may have a first cross-sectional area Ap1 and a first diameter Dp1, second port 112B may have a second cross-sectional area Ap2 and a second diameter Dp2, third port 112C may have a third cross-sectional area Ap3 and a third diameter Dp3, fourth port 112D may have a fourth cross-sectional area Ap4 and a fourth diameter Dp4). As described above, each of the valves 110A-D may open and close its corresponding port 112A-D during operation of the engine assembly 10.
The combustion chamber surface 55 of the cylinder head 54 may include a spark plug boss 114 and a fuel injector boss 116. A spark plug (not shown) may be arranged within the spark plug boss 114 and a fuel injector 28 may be arranged within the fuel injector boss 116. As illustrated in
In the illustrated example of
The exact placement of the spark plug and fuel injector bosses 114, 116 may vary even when being arranged centrally on the combustion chamber surface 55. By way of non-limiting example, the spark plug boss 114 may have a first center point Cs that may be offset from a third center point Cc of the combustion chamber surface 55 by a first offset Os. Further, the fuel injector boss 116 may have a second center point Cf that may be offset from the third center point Cc of the combustion chamber surface 55 by a second offset Of. Because the spark plug boss 114 may be larger than the fuel injector boss 116, the second offset Of may be greater than the first offset Os. In this manner, the first valve 110A and the first center point Cs of the spark plug boss 114 may be present on a first side of the combustion chamber 60 and combustion chamber surface 55. Further, the second valve 110B and the second center point Cf of the fuel injector boss 116 may be present on a second side that is opposite the first side of the combustion chamber 60 and combustion chamber surface 55.
In a non-limiting example, the first valve 110A and the second valve 110B may comprise exhaust valves (such as exhaust valves 52) and the first port 112A and the second port 112B may comprise first and second exhaust ports (such as exhaust ports 64). The third valve 110C and the fourth valve 110D may comprise intake valves (such as intake valves 50) and the third port 112C and the fourth port 112D may comprise intake ports (such as intake ports 62). In this example, as shown in
The size of the valves 110A-D and ports 112A-D may be limited by the unutilized surface area of the combustion chamber surface 55. In the non-limiting example illustrated in
In the non-limiting example illustrated in
An asymmetric valve configuration may include different sizes for each valve and/or port in a set of either exhaust or intake valves and ports. As illustrated in
By way of non-limiting example, the second surface area Av2 of the second valve 110B may be at least ten percent, and more specifically between fifteen and twenty percent, greater than the first surface area Av1 of the first valve 110A. Similarly, the second cross-sectional area Ap2 of the second port 112B may be at least ten percent, and more specifically between fifteen and twenty percent, greater than the first cross-sectional area Ap1 of the first port 112A. Further, the second diameter Dv2 of the second valve 110B may be at least five percent, and more specifically between six and ten percent, greater than the first diameter Dv1 of the first valve 110A. Similarly, the second diameter Dp2 of the second port 112B may be at least five percent, and more specifically between six and ten percent, greater than the first diameter Dp1 of the first port 112A.
For example only, for a cylinder diameter Dc of approximately 74 millimeters, the first diameter Dv1 of the first valve 110A (and/or the first diameter Dp1 of the first port 112A) may be approximately 24 millimeters and the second diameter Dv2 of the second valve 110B (and/or the second diameter Dp2 of the second port 112B) may be approximately 26 millimeters. In a further non-limiting example, for a cylinder diameter Dc of approximately 74 millimeters, the first diameter Dp1 of the first port 112A may be approximately 24 millimeters and the second diameter Dp2 of the second port 112B may be approximately 26 millimeters.
