Field of the Invention
A positive crankcase ventilation gas diversion system includes a positive crankcase ventilation gas diversion line to divert oil laden PCV gases from the air intake manifold of an internal combustion engine. The oil laden PCV gases are directed through an oil-vapor diffuser to at least partially separate crankcase oils from the PCV gases before the stripped gases are returned to the air intake manifold of the engine.
Description of the Related Art
Until recent years, internal combustion engines in automobiles typically employed an indirect or port fuel injection system, such as is shown by way of example in FIG. 3. As may be seen from FIG. 3, aerosolized fuel is injected into the air intake manifold, where it is mixed with the fresh air intake as well as with oil laden positive crankcase ventilation (“PCV”) gases vented from the crankcase into the air intake manifold. More importantly, by injecting aerosolized fuel into the air intake manifold, the fuel served to continually “wash” the valve and valve stem, thereby minimizing the build of oil residue from the oil laden PCV gases.
Faced with increased fuel efficiency requirements, particularly in the United States, many automobile manufacturers began utilizing direct fuel injection, such as is shown by way of example in FIG. 4. As is readily apparent from FIG. 4, the direct fuel injector(s) inject fuel downstream of the valve and valve stem, therefore, there is no continuous flow of fuel to “wash” these components. As a result, even after moderate operation of about 60,000 miles, substantial carbon buildup from baked on oil residue is visible, such as is shown in the photograph presented in FIG. 2. This buildup, at a minimum, results in significantly reduced operation efficiency, thereby defeating the purpose of the direct fuel injection system. More importantly, in many cases the carbon buildup leads to premature catastrophic engine failure, thus requiring replacement or rebuilding, at considerable expense to the owner.
Various methods of cleaning carbon buildup from valves and valve stems, such as is shown in the photograph in FIG. 2, have been proposed, but none are believed to be more than nominally effective, and all are extremely time and labor intensive, and thus, expensive for the owner to undertake.
One attempt to resolve the problems created by direct fuel injection has been to provide both indirect and direct fuel injectors. As will be appreciated, this results in a decrease in efficiency, relative to an engine having direct fuel injection itself, with the further disadvantage of the considerable added expense of building an engine having multiple fuel injectors and the corresponding control systems for the same. Furthermore, this solution does not readily lend itself to the retrofit of an engine originally equipped solely with direct fuel injection.
A further problem with operation of an internal combustion engine, regardless of whether it employs indirect fuel injection, direct fuel injection, or a combination of the two, is that a certain amount of crankcase oils entrained in the positive crankcase ventilation gases enter the combustion chamber. Unfortunately, combustion of crankcase oils is much less than complete, leading to an increase in harmful emissions, as well as a corresponding decrease in fuel efficiency. This problem is exacerbated as carbon buildup from baked on oil residue begins to occur on the valves, valve stems, and related components. Specifically, carbon buildup obstructs airflow to the combustion chamber, again, leading to incomplete combustion, increased emissions, and reduced fuel efficiency. Carbon buildup occurs even in engines having indirect fuel injectors, albeit to a much lesser degree. This is due to the fact that the air intake stroke, and thus the time for oil laden positive ventilation crankcase gases to enter the combustion chamber is much longer than the fuel injector spray cycle time. Therefore, only a portion of the incoming raw crankcase oils entrained in the positive ventilation crankcase gases are “washed” out of the gases via indirect fuel injectors, while the remainder of the raw crankcase oil particles are directed into the combustion chamber where they are only partially combusted, as described above.
As such, it would be extremely beneficial to provide a system which significantly reduces if not eliminates carbon buildup from oil residue on the valve, valve stem, and other moving components of an internal combustion engine employing direct injection, without sacrificing the fuel efficiency thereof. It would be further advantageous to provide a system which may be easily installed as either original equipment or retrofitted to an existing internal combustion engine assembly employing direct injection having minimal parts and relative cost. It would also be useful to provide a system for an internal combustion engine employing direct injection which not only removes crankcase oils from oil laden PCV gases, but dissolves the crankcase oils into liquid fuels or other suitable solvents for combustion therewith. Another benefit may be realized by providing a method for reducing harmful positive crankcase ventilation gas emissions during operation of any internal combustion engine, regardless of the type of injection system employed, by minimizing if not eliminating the introduction of raw crankcase oils entrained in positive ventilation crankcase gases from entering the combustion chamber.