Patent Application
20130042844
The present disclosure relates to engine positive crankcase ventilation systems.
This section provides background information related to the present disclosure which is not necessarily prior art.
Internal combustion engines may combust a mixture of air and fuel in cylinders and thereby produce drive torque. A portion of the combustion gases (blowby) may escape the combustion chamber past the piston and enter the engine crankcase. Crankcase ventilation systems may be incorporated into engines in order to mitigate the effects of blowby gases in the crankcase.
An engine assembly may include an engine structure, an intake air assembly and a crankcase ventilation line assembly. The engine structure may define a cylinder bore, an intake port in communication with the cylinder bore, and a crankcase. The air intake assembly may be in communication with the intake port. The crankcase ventilation line assembly may include a fresh air line and an oil surge protection device. The fresh air line may be in communication with the crankcase and the air intake assembly and may provide fresh air to the crankcase. The oil surge protection device may be in communication with the fresh air line and may define an oil obstruction inhibiting oil flow to the air intake assembly while allowing air flow between the crankcase and the air intake assembly.
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.
As seen in
The engine structure 14 may define a crankcase 42 in communication with the air intake assembly 24 via the crankcase ventilation line assembly 26. The crankcase 42 may be in communication with a volume 44 defined by the cylinder head 34 and cylinder head cover 36 via passages (not shown) defined by the cylinder head 34. The valvetrain assembly 16 may include intake and exhaust valves 46, 48, intake and exhaust camshafts 50, 52, intake valve lift mechanisms 54 engaged with the intake valves 46 and the intake camshafts 50 and exhaust valve lift mechanisms 56 engaged with the exhaust valves 48 and the exhaust camshafts 52.
The air intake assembly 24 is in communication with the intake ports 38 and may include an air induction assembly 58, a throttle valve 60 and an intake manifold 62. The crankcase ventilation line assembly 26 may be in communication with the crankcase 42 and the air intake assembly 24 and may include a fresh air line 64, a foul air line 66 and an oil surge protection device 68. The fresh air line 64 may be in communication with the crankcase 42 and the air intake assembly 24 at a location upstream of the throttle valve 60 to provide fresh air to the crankcase 42. In the present non-limiting example, the fresh air line extends from the cylinder head cover 36 to the air induction assembly 58 and is in communication with the volume 44 defined by the cylinder head 34 and the cylinder head cover 36. The foul air line 66 may be in communication with the crankcase 42 and the air intake assembly 24 at a location downstream of the throttle valve 60 to remove blowby gases from the crankcase 42. A PCV separator (not shown) may be located in the flow path from the crankcase 42 to the foul air line 66 to remove oil from the blowby gases before the gases reach the air intake assembly 24.
The oil surge protection device 68 may be in communication with the fresh air line 64 and defines an oil obstruction inhibiting oil flow to the air intake assembly 24. With additional reference to
The air outlet 70 and the air inlet 72 may be offset relative to one another and relative to a longitudinal centerline (L) of the chamber 74. More specifically, the air outlet 70 may be offset radially upward relative to the air inlet 72. In the present non-limiting example, a centerline (Co) of the air outlet 70 is radially offset from a centerline (Ci) of the air inlet 72 by a distance greater than a diameter (Do) defining the air outlet 70. More specifically, the entire air outlet 70 may be located in an upper radial half of the chamber 74 and the entire air inlet 72 may be located in lower radial half of the chamber 74. The radial offset between the air outlet 70 and the air inlet 72 may form an oil obstruction to inhibit oil flow in a direction from the air inlet 72 toward the air outlet 70 as discussed below.
During operation, oil may accumulate in the volume 44 defined between the cylinder head 34 and the cylinder head cover 36. Due to the transverse mounting of the engine assembly 12 within the vehicle 10, during high-g turns oil may rush to and accumulate at the rear of the volume 44 defined between the cylinder head 34 and the cylinder head cover 36. In the non-limiting example illustrated, oil may rush to the rear of the cylinder head 34 during right turns (indicated by arrow “L” in
The oil surge protection device 68 may inhibit oil flow through the fresh air line 64 to the air intake assembly 24. More specifically, due to the offset between the air outlet 70 and the air inlet 72, a wall 80 may be formed at an end of the chamber 74 below the air outlet 70. Therefore, when oil enters the oil surge protection device 68 during high-g turns, the oil impacts the wall 80 and is preventing from flowing directly into the second portion 78 of the fresh air line 64, and ultimately to the air intake assembly 24. The lower location of the air inlet 72 provides for return flow of oil to the volume 44. The oil surge protection device 68 may additionally include a longitudinally extending wall 82 below the air outlet 70 and a longitudinally extending wall 84 above the air inlet 72 to further prevent oil from flowing directly into the second portion 78 of the fresh air line 64.
Alternate oil surge protection devices 168, 268 are illustrated in
