Internal-combustion engines – Four-cycle – Single poppet valve
Reexamination Certificate
1999-04-21
2001-05-29
Wolfe, Willis R. (Department: 3747)
Internal-combustion engines
Four-cycle
Single poppet valve
C123S188200
Reexamination Certificate
active
06237549
ABSTRACT:
BACKGROUND
The invention here disclosed relates primarily to a reciprocating intake valve for controlling the movement of air/fuel mixture into the combustion chamber (cylinder) of internal combustion engines.
In typical internal combustion engines the valves that control the flow of atmosphere to and from the combustion chamber are one piece, with one spring retainer, and various spring control arrangements.
Since the efficiency of this valve arrangement is a major factor in the performance of the entire engine, many attempts at maximizing the potential flow dimension of these valves have been explored. Since a homogeneous air/fuel mixture is also an important factor in the performance of internal combustion engines, many attempts to use the one piece valve arrangement in different ways to create a swirl effect have also been explored. Increasing the flow dimension allowed by the intake valve automatically increases the power of the engine. Creating a more homogeneous air/fuel mixture also automatically increases the power of the engine by breaking down the fuel into smaller particles that can be more easily combusted, which, more importantly, increases the fuel efficiency and reduces the environmentally harmful emissions of internal combustion engines.
Since the timing and control of this valve arrangement is also a major factor in the performance of the entire engine, many attempts to maximize valve timing over a broad range of constantly variable conditions, such as load, speed, and atmosphere, have been explored.
It is toward these fundamental factors of improved flow dimension (volume), homogeneous air/fuel charge conditioning, and multi-dimensional, constant variable valve timing, that the here disclosed invention takes a giant step forward, by accomplishing all three at the same time.
It is further the intent of the here disclosed invention(s) to address other important factors revealed through the extensive testing and study of early vented valve designs. Such as the type disclosed in U.S. Pat. No. 5,357,914, issued to Huff. While these early designs integrate two main valve elements in a manner broadly similar to the here disclosed invention, they incorporate a cross pin inner valve retention system. This arrangement complicates the manufacture of the valve units by requiring precise vertical slots to be machined into the stem of the outer valve, and small precise cross drilled holes into the stem of the inner valve.
In addition, these designs require recessed spring landing sections to be machined into the outer valve stems. This arrangement makes installation of the inner valve control spring(s) and subsequently the aforementioned retainer pin(s) cumbersome, making automation of the entire assembly challenging.
It further utilized the hollow outer valve stem as a guide for the inner valve stem. This makes otherwise normal and acceptable outer valve head and stem deflection unacceptable. this can cause inner valve stem binding, which adversely effects its performance and promotes premature wear.
It further utilizes a single inner valve seat on the outer perimeter of the inner valve head. This arrangement can promote independent inner valve head deflection and subsequently inner valve bounce, especially at high speeds.
It further tends to promote over lubrication by communicating an inner valve pocket low pressure signal through the aforementioned pin slots to the outer valve stem seal, pulling excess lubrication past it and into the working mechanism.
It further compromises longevity by not allowing inner valve rotation independent of the outer valve, and making the use of special guide material, such as cast iron, for the inner valve stem impractical.
It further slightly increases the risk over standard valves of sudden outer valve main guide failure due to the possibility of small spring burrs or chips dislodging within the guide and lodging in-between the stem and guide, and damaging both the guide and the valve stem.
Additionally, a minor factor concerning these designs relates to ease of implementation or retrofit. Besides the somewhat larger outer valve stem outside diameter it requires, the inner valve pin and spring arrangement make the design and placement of the outer valve main guide more critical. This also makes universal production between similar applications less feasible.
It is to these fundamental factors effecting the performance, longevity, manufacturability, retrofitability, and cost of vented valves, that the here disclosed invention takes another giant step forward, by accomplishing vast improvements in all areas of concern at the same time, while providing the exceptional bonus of self regulated dampening of the inner valve closing function. Further clarification of the advantages and features of the present invention(s) is provided within the specification.
BRIEF SUMMARY OF INVENTION
This invention relates primarily to engine valving, and, in particular, the reciprocating valves necessary for the intake of air/fuel mixture into the combustion chambers of conventional internal combustion engines, wherein the intake valve head incorporates vents in order to vastly improve the flow dimension allowed during the time constrained operation of the intake valve.
In order to obtain the maximum power output and efficiency of conventional internal combustion engines it is necessary to maximize the flow dimension of the air/fuel mixture and exhaust gases to and from the combustion chamber. The traditionally accepted method used to attempt this is by use of single stage (function) reciprocating intake and exhaust valves, actuated by a cam transferring a predetermined displacement sequence motion to a rocker arm that transfers its motion to the tip of the valve stem, controlling the valve's displacement and timing.
The invention disclosed herein is an intake valve for internal combustion engines that automatically takes in atmosphere in two stages and creates a multi-layered flow path, instead of a conventional single layer flow path, to allow more atmosphere into the combustion chamber, and, in addition, allow for a broader timing range of flow events, thereby maximizing engine performance at all engine speeds.
In the preferred embodiments the intake vented valve is designed with an inner valve and an outer (main) valve. The outer valve is designed with vents in is head portion that communicate between the intake port and the combustion chamber. The vents are releasably sealed off by the inner valve head.
In the preferred embodiment therein the inner valve and the inner valve guide, control spring, and retainer clip are pre-assembled.
The outer valve is designed with a hollow stem sized to allow a secure press fit of the inner valve guide. The two main elements are mated by pressing the entire inner valve mechanism along with the inner valve guide into the hollow outer valve stem, retaining the inner valve and completing the vented valve assembly.
In an alternative embodiment the outer (main) valve is constructed in two major parts. The outer valve head and fillet segment, and the stem segment. The stem segment also includes a hollow portion which runs from the opposite end of the tip end towards the tip end.
The valve head segment is assembled with the inner valve stem protruding through a through bore which runs through the center of the valve head segment and acts as a guide for the inner valve stem. A spring is installed on top of the stem base portion of the valve head segment around the protruding portion of the inner valve stem. The spring and inner valve are retained by a retainer clip arrangement.
The stem segment is pressed onto the stem base of the valve head segment over the inner valve retainer and control spring arrangement encapsulating the inner valve control means within the hollow portion of the stem segment. The stem segment can then be laser or friction welded in place.
In another alternative embodiment the outer valve is designed in a single piece arrangement in a similar fashion to the preferred embodiment above. The inner val
Acro-Tech, Inc
Benton Jason A
Wolfe Willis R.
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