Internal-combustion engines – Intake manifold
Reexamination Certificate
2003-01-22
2003-11-25
Delcotto, Gregory (Department: 1751)
Internal-combustion engines
Intake manifold
C123S05000B, C123S19800E, C123S184480
Reexamination Certificate
active
06651604
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device for delivering a cleaning composition into a desired location within the interior cavity of a reciprocating internal combustion engine. Such a device has at least one orifice located inside the engine cavity and allows for administration of the cleaning composition to a specified interior location, for example, at the point of a problematic deposit; thereby allowing for a fluid delivery point that is independent of the fuel delivery system and without constraints of solely relying upon combustion air (or other external means) as the carrier, to deliver the cleaning composition to a carbonaceous deposit requiring removal. This device is useful for removing engine deposits in a reciprocating internal combustion engine by directing a substantial portion of the cleaning composition at the point of, or in close proximity to, the deposit in the interior of the engine. More particularly, this invention relates to a device and application tool containing the same, which allows for the controlled delivery of a cleaning composition to one or more specified locations within the interior cavity of a reciprocating internal combustion engine having a least one interior surface to be cleaned.
2. Description of the Related Art
It is well known that reciprocating internal combustion engines tend to form carbonaceous deposits on the surface of engine components, such as carburetor ports, throttle bodies, fuel injectors, intake ports and intake valves, due to the oxidation and polymerization of hydrocarbon fuel, exhaust gas recirculation (EGR), positive crankcase ventilation (PCV) gases. It is believed that some of the unburnt hydrocarbons in the fuel undergoes complex cracking, polymerization and oxidation reactions, leading to reactive moieties which can interact with the fuel, recirculated gases and lubricating oils; thus forming insolubles in the combustion chamber and combustion pathways. These deposits, even when present in relatively minor amounts, often cause noticeable operational performance issues such as driveability problems including stalling and poor acceleration, loss of engine performance, increased fuel consumption and increased production of exhaust pollutants.
Fuel based detergents and other additive packages have been developed, primarily in gasoline fuels, to prevent the formation of these unwanted deposits. As a consequence, problems in fuel delivery systems, including injector deposit problems, have been significantly reduced. However, even after employing these detergent additives, injectors and other components require occasional additional cleaning to maintain optimum performance. The present additives and delivery devices are not completely successful eliminating deposits, especially for removing preexisting heavy deposits or deposits upstream of the fuel entry. Often these preexisting and upstream deposits require complete engine tear down. Attempts have been made to use higher concentrations of detergents and additives in the fuel but, since these detergents are mixed with the fuel, they are generally employed at concentrations less than 1% (primarily for compatibility with elastomers, seals, hoses and other components) in the fuel system. Moreover, for these detergent additives in the fuel to remove deposits from the various parts of an engine, they needed to come into contact with the parts that require cleaning.
Specific engine configurations have more pronounced problematic deposit areas due to the intake systems. For example, throttle body style fuel injector systems where the fuel is sprayed at the initial point of air flow into the system allows the intake to remain reasonably clean using the fuel additive, however port fuel injection spark ignition (PFI SI) engines spray the fuel directly into the air stream just before the intake valves and direct injection spark ignition (DISI) engines and many diesel engines spray the fuel directly into the combustion chamber. As a result, upstream components from the fuel entry on the intake manifold of PFI SI and DISI engines are subject to increased formation of unwanted deposits from oil, from the positive crankcase ventilation (PCV) system, and from exhaust gas recirculation (EGR) system. These upstream engine air flow components can remain with engine deposits even though a detergent is used in the fuel. Moreover, even with the use of detergents, some engine components when present, such as intake valves, fuel injector nozzles, idle air bypass valves, throttle plates, EGR valves, PCV systems, combustion chambers, oxygen sensors, etc., require additional cleaning.
Several generic approaches were developed to clean these problematic areas often focusing on the fuel systems. One common procedure is applying a cleaning solution directly to the carburetor into an open air throttle or the intake manifold of a fuel injection system, where the cleaner is admixed with combustion air and fuel, and the combination mixture is burned during the combustion process. These carburetor-cleaning aerosol spray cleaning products are applied from an external location into a running engine. The relatively slow delivery rate as well as the structure of the carburetor/manifold systems generally prevent the accumulation of cleaning liquid in the intake of the engine. However as is apparent for the intake manifold, the majority of the cleaner will take the path of least resistance to the closest combustion chamber of the engine often leading to poor distribution and minimal cleaning of some cylinders.
This technique has also been modified, to introduce a cleaning solution to the intake manifold through a vacuum fitting. Generally, these cleaning solutions are provided in non-aerosol form, introduced into a running engine in liquid form using engine vacuum to draw the product into the engine, as described in U.S. Pat. No. 5,858,942 issued Jan. 12, 1999. While these newer products may be generally more effective at cleaning the engine than the conventional aerosol cleaners, they suffer from a distribution problem in getting the cleaner to the multiple intake runners, intake ports, intake valves, combustion chambers, etc. Typically, the cleaning product was introduced into the intake manifold via a single point by disconnecting an existing vacuum line on the manifold and connecting a flex line from that vacuum point to a container containing the cleaning liquid and using engine vacuum to deliver the cleaning solution to that single port. While a metering device could be used limit the rate at which the cleaning solution was added to the intake manifold, the locations for addition of cleaning solution were fixed by the engine design of vacuum fittings on the intake manifold. Often such arrangements favored introduction of cleaning solution to some of the cylinders while others received less or none of the cleaning solution. More problematic is that some engine designs have an intake manifold floor, plenum floor or resonance chamber, which has a portion lower than the combustion chamber of the engine. This type of design will allow for a cleaning solution to pool in these areas. This aspect, as well as introducing the cleaning solution at too great a rate, can accumulate and pool the cleaning solution in the manifold even though the engine is running. Generally, the vacuum generated within the manifold is not sufficient to immediately move this pooled liquid or atomize the liquid for introduction into the combustion chamber. However, upon subsequent operation of the engine or at higher engine speed, a slug of this liquid can be introduced into the combustion chamber. If sufficient liquid is introduced into the combustion chamber, hydraulic locking and/or catastrophic engine failure can result. Hydraulic locking and engine damage can result when a piston of the running engine approaches its fully extended position towards the engine head and is blocked by essentially an incompressible liquid. Engine operation ceases and engine internal damage often results.
Ac
Ahmadi Majid R.
Vaudrin Damon C.
Caroli Claude J.
Chevron Oronite Company LLC
Delcotto Gregory
Foley Joseph P.
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