Self-cleaning internal combustion engine intake valve

Information

  • Patent Grant
  • 6832595
  • Patent Number
    6,832,595
  • Date Filed
    Monday, February 24, 2003
    21 years ago
  • Date Issued
    Tuesday, December 21, 2004
    20 years ago
Abstract
A self-cleaning valve for removing hydrocarbon deposits from pressure responsive automatic air intake valves in an internal combustion engine. The self-cleaning valve assembly of the present invention removes soot which naturally accumulates on the surface of the valve as a result of the heat generated by the combustion event when hydrocarbon fuel sources are used. A reciprocating slider is seated within a bushing. The bushing is fluted with small relief passages along its length. The fluted relief passages run more or less parallel to the direction of the movement of the slider, and provide channels for removing soot from the surface of the valve. Repeated closing of the slider hammers soot upwardly into the relief passages, thereby maintaining the valve free of potentially fouling hydrocarbon deposits.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to intake valves, and more particularly to an automatic air intake valve in an internal combustion engine with self-cleaning feature for removing hydrocarbon deposits.




2. Description of the Background




The present invention relates to intake valves used in an internal combustion engine.

FIGS. 1-8

diagrammatically depict the cycle of an internal combustion engine. As shown in

FIG. 1

, the components of the internal combustion engine generally comprises an engine block


10


having a plurality of cylinders


12


. Each cylinder


12


houses a piston


14


connected to a crankshaft


16


via a piston rod


18


as is commonly known to those skilled in the art. Each cylinder includes an intake valve


20


for admitting air prior to the compression event, and an exhaust valve


22


for venting exhaust fumes following the compression event. Exhaust valve


22


may alternatively be an exhaust port positioned along a sidewall of cylinder


12


as more fully described in U.S. Pat. No. 6,257,180 to Klein. The particular type of intake valve


20


shown in

FIG. 1

is a pressure responsive automatic air intake valve for use in a forced coaxially ventilated two stroke or four power plant. Such a valve opens and closes in response to differences in air pressure between the intake manifold and the combustion chamber (cylinder).




For illustrative purposes, the four stroke engine cycle can be broken down into seven sequential events, each event corresponding to a specific position of the piston


14


, intake valve


20


and exhaust valve


22


.




As shown in

FIG. 1

, the cycle begins with piston


14


at the top dead center position within cylinder


12


. Both intake valve


20


and exhaust valve


22


are in the closed position.





FIG. 2

shows the second position or “intake” wherein piston


14


travels downwardly through cylinder


12


, and intake valve


20


opens allowing air to be inducted into the chamber of cylinder


12


.





FIG. 3

represents the next distinct step in the engine cycle wherein piston


14


reaches bottom dead center in cylinder


12


and intake valve


20


closes again.





FIG. 4

shows the “compression” stage wherein piston


14


moves upwardly through cylinder


12


compressing the mixture of air and gas in the cylinder. Both intake valve


20


and exhaust valve


22


remain in the closed position.





FIG. 5

shows the “power” stage in which piston


14


is driven downward once again through chamber


12


, until it reaches bottom dead center as shown in FIG.


6


.

FIG. 7

shows the next sequential stage or the “exhaust” stage wherein piston


14


travels once more upwardly through cylinder


12


, and exhaust valve


22


opens allowing the accumulated exhaust gasses to be expelled from the chamber of the cylinder


12


. As shown in

FIG. 8

, at the end of the “exhaust” stage piston


14


reaches top dead center once more, exhaust valve


22


closes, and the engine cycle repeats itself.




The cycle is known as the Otto Cycle and is well known by those skilled in the art as a means for generating power via an internal combustion engine.




The adherence of soot and impurities to the sidewall of the valves and surrounding surfaces is an unavoidable consequence of the combustion of hydrocarbon fuel. Over time, accumulated sootmight obstruct the proper opening and closing of the valve. The object of the instant invention is to overcome this drawback and to provide a self-cleaning valve assembly for removing the potentially fouling soot.




The problem of hydrocarbon build-up in the combustion chamber of engines such as the above is well known. Prior solutions, however, have been directed towards flushing away the accumulated soot deposits. For example, U.S. Pat. No. 6,178,944B I to Kerns et al. teaches a method wherein additional fuel is injected into the combustion chamber, drawn into the intake manifold and subsequently inducted back into the combustion chamber past the intake valve to flush carbon deposits from the intake valve and surrounding surfaces. Unfortunately, the cleaning method of Kerns et al. is inefficient because it requires certain steps in addition to the normal engine cycle. This in turn requires more internal engine parts, and more maintenance.




A second example is shown in U.S. Pat. No. 5,286,264 to Russo, et al. Russo '264 teaches a gasoline detergent additive composition for flushing hydrocarbon deposits from internal engine components. Unfortunately, the detergent is only useful for removing hydrocarbon deposits after they have formed, rather than removing the fouling deposits as they form.




Absent from the prior art is a method for mechanically removing the accumulated hydrocarbon deposits from an engine valve. Accordingly, it would be advantageous to provide a self-cleaning engine valve and valve guide for mechanically removing hydrocarbon deposits. It further be advantageous to provide a self-cleaning engine valve for mechanically removing hydrocarbon deposits using the normal movement of an engine during the cycle of ventilation, compression, and combustion.




SUMMARY OF THE INVENTION




It is, therefore, an object of the present invention to provide a self-cleaning valve assembly for mechanically removing accumulated hydrocarbon deposits from the surface of the valve.




It is another object of the present invention to provide a self-cleaning valve assembly for mechanically removing accumulated hydrocarbon deposits from the valves of an internal combustion engine which uses the movement of the engine during the normal cycle of ventilation, compression, and combustion.




According to the present invention, the above-described and other objects are accomplished by providing a bushing which houses a reciprocating slider valve member. The inner walls of the bushing are fluted with small relief passages which run parallel (more or less) to the direction of the movement of the slider. As soot accumulates in the valve seat and side walls of the slider, it is collected in the flutes when the valve closes. Repeated closing of the valve hammers the soot higher into the fluted relief passages, while the vertical movement of the slider shears any soot which protrudes into its path from the flutes. The soot thereafter mixes with the intake air to be recombusted or wasted along with the portion of incoming air which cools the cylinder.











DESCRIPTION OF THE DRAWINGS





FIGS. 1-8

(Prior Art) are sectional views of an internal combustion engine having a self-cleaning valve of the instant invention wherein the relative positions of the power piston, intake valve, and exhaust valve are shown in the following sequential positions: top dead center; intake; bottom dead center; compression; power; bottom dead center; exhaust; and top dead center.





FIG. 9

is an exploded view of the valve guide and valve of the self-cleaning valve of the instant invention.





FIG. 10

a composite side perspective view of slider


34


(left) and a side cross-sectional view of slider


34


(right).





FIG. 11

is a partial sectional view of the bushing of the self-cleaning valve assembly of the present invention showing the fluted relief passages.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




The improved valve structure of the present invention is herein described in the context of the intake valve


20


shown in the above-described '180 patent (a pressure responsive automatic air intake valve for use in a forced coaxially ventilated two stroke or conventional four stroke power plant). However, those skilled in the art will understand that the improved valve has application wherever particulates pose a valve clogging problem.





FIG. 9

is an exploded perspective view of the improved self-cleaning intake valve


20


of the instant invention with a slider


34


(bottom) shown removed from within a valve housing


30


.




Valve


20


is configured as a pressure responsive valve which opens automatically in response to a pressure of approximately 1 psi. The valve cycles between an open and closed position in the course of the engine cycle, opening to allow delivery of fresh air into the combustion cylinder, and closing to prevent backflow of uncombusted air as described more fully above.




Valve housing


30


includes a hollow cylindrical bushing


72


with an integral rim


70


at the lower end. The valve housing


30


may be cast integrally as part of a cylinder head, or it may be a separate component as shown which is attached to the cylinder head by external threads as described in the '180 patent. It should be apparent to those skilled in the art that the valve housing


30


may be formed and installed in various other known ways. For example, valve housing


30


may be stamped and press-fit, etc. The rim


70


has an expanded outside diameter and serves as a valve seat for slider


34


as described more fully below.




Slider


34


is substantially as described in U.S. Pat. No. 6,257,180 to Klein, and is herein seen with reference to

FIG. 10

, which is a composite side perspective view of slider


34


(left) and a side cross-sectional view of slider


34


(right). Slider


34


comprises an elongate hollow cylinder


68


dimensioned to fit snug, but also slide freely within valve housing


30


. The top end of cylinder


68


is open, and the bottom end is closed with a cap


60


. Chamfered walls


62


extend upwardly from cap


60


to cylinder


68


thereby joining the two elements. A plurality of openings


66


are provided around the circumference of cylinder


68


immediately adjacent to end cap


60


. Openings


66


provide a path of travel for air directed through intake valve


20


, as more fully shown in the '180 patent. When valve


20


is fully closed, the end cap


60


of slider


34


rests flush against the rim


70


of valve housing


30


, thereby covering openings


66


and sealing the valve closed.




Slider valve member


34


may be provided with a pair of opposing bore holes


80


on the top rim cylinder


68


. Bore holes


80


are configured to receive a pin


84


(see

FIG. 1

) when the valve is assembled. When the slider


34


is inserted within the housing


30


, the distal ends of pin


84


are captured within a pair of opposing grooves


86


(one of which is visible in

FIG. 9

) that are formed on the inner wall


44


of housing


30


. Grooves


86


extend approximately to the mid-point of housing


30


, thereby allowing slider


34


to partially extend from the bottom of housing


30


. This configuration limits the path of travel of slider valve member


34


within valve housing


30


, and likewise prevents the inadvertent withdrawal and removal of slider valve member


34


from housing


30


during operation.




Alternatively, one or more slots may be machined into the slider


68


parallel to its direction of movement. One or more dowels may be inserted through the valve guide


72


, which will protrude through the slot(s), thereby limiting the distance of travel of the slider


68


.




As yet another alternative to the foregoing pin


84


and groove


86


configuration, it is possible to machine a groove, parallel to the direction of valve motion, completely through the wall of the valve


30


. A hardened steel pin is then anchored in the cylinder head, through the cylindrical bushing


72


perpendicular to the motion of the slider


34


.




Referring now to

FIG. 11

, valve housing


30


comprises a cylindrical bushing


72


which defines an outer wall


42


, an inner wall


44


forming a cylindrical first channel for receiving slider valve member


34


, a top edge


43


, and a bottom edge


41


that is a hardened valve seat (where the foot of the valve seals the passage into the cylinder head). There is a circular seam


76


at the base of inner wall


44


(where bushing


72


meets rim


70


), and below seam


76


the inner face


71


of rim


70


flares outwardly to accommodate cap


68


. Top edge


43


is defined by the top of bushing


72


, and bottom edge


41


is defined by the bottom face of rim


70


. In accordance with the present invention, inner wall


44


is fluted with a plurality of parallel second channels


46


which run from top edge


43


to seam


76


. The second channels


46


form shallow elongate grooves, preferably with semi-circular cross sections in inner wall


44


, open to the hollow interior of housing


30


. The second channels


46


are preferably evenly spaced around the perimeter of inner wall


44


. The top end of each channel


46


is open, forming a first semi-circular aperture


47


in top edge


43


. The bottom end of each channel


46


is likewise open, forming a second semi-circular aperture


49


at seam


76


.




The operation of the valve


20


is best understood with reference to the exploded view of FIG.


9


. Inner wall


44


of housing


30


lightly contacts outer wall


67


of slider


34


. Soot adhering to outer wall


67


is mechanically scraped off and collected in apertures


49


at the base of housing


30


. As slider


34


continues to move upwardly to a closed position within housing


30


, the soot is pushed farther upward into channels


46


. The force of slider


34


closing against valve housing


30


hammers the soot upward into channels


46


. Each repetitive closing of slider


34


collects more soot, and forces the accumulated soot higher and higher into channels


46


. When the soot reaches the top of channel


46


, it is expelled through aperture


47


, and thereafter falls into the hollow center of slider valve member


34


, where it is inducted into compression chamber of cylinder


12


in the subsequent intake cycle.




If the soot extends beyond the arc shaped recesses of channel


46


into the hollow center of housing


30


, it is sheared off by slider


34


as it closes within valve housing


30


. The sheared off soot drops into the hollow center of slider


34


, where it is inducted into compression chamber of cylinder


12


in the subsequent intake or ventilation cycle.




The self-cleaning mechanism of the instant invention maintains the valve in an operational state nearly free of potentially fouling soot. Further, the mechanism disclosed herein is highly efficient because it cleans the valve using the existing cycle of opening and closing, and thereby eliminates the need for additional movement within the engine or the use of detergent additives. Finally, the self-cleaning mechanism of the present invention continuously cleans the valve as soot accumulates (as distinguished from detergents which are only useful for rinsing away accumulated deposits), thereby maintaining optimal engine performance.




Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims:



Claims
  • 1. A self-cleaning valve for an internal combustion engine, comprising:a housing configured as an elongate hollow bushing having a first end and a second end, and having an inner wall forming a cylindrical first channel for receiving a slider valve member, said inner wall further defined by a plurality of second channels extending from said first end to said second end; and said slider valve member configured for reciprocating movement within said bushing, said slider valve member further comprising a hollow elongate cylinder having an open first end and a closed second end; whereby hydrocarbon deposits collect on said cylindrical slider valve member during operation of said internal combustion engine and, whereby each time said slider valve reciprocates within said housing said hydrocarbon deposits are scraped from said slider valve, forced through said plurality of second channels and expelled.
  • 2. The self-cleaning valve as in claim 1, wherein said plurality of second channels are all substantially parallel.
  • 3. The self-cleaning valve as in claim 2, wherein each of said second channels comprises a recess formed in said inner wall; said recess having a semi-circular cross section opening to an interior of said housing, said second channel recesses each having a first aperture at one end and a second aperture at another end to facilitate egress and ingress of deposits collected from said slider valve member.
  • 4. The self-cleaning valve as in claim 3, wherein said second channels are all substantially evenly spaced.
  • 5. The self-cleaning valve as in claim 4, wherein said slider valve member is configured to fit snug, but also slide freely within said first channel of said housing; wherein said hydrocarbon deposits are scraped off said slider valve member by said second end of said housing as the slider valve slides into said first channel; and wherein said hydrocarbon deposits are collected at said second end of said housing and then forced into said second apertures of said plurality of second channels, through said plurality of second channels and out said first apertures, as said slider valve reciprocates, thereby cleaning said slider valve member.
CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application derives priority from U.S. Provisional application Ser. No. 60/359,611 filed Feb. 25, 2002.

US Referenced Citations (1)
Number Name Date Kind
3675825 Morane Jul 1972 A
Provisional Applications (1)
Number Date Country
60/359611 Feb 2002 US