Patent Application
20090140623
1. Field of the Invention
The present invention relates to internal-combustion engine components, and more particularly, to efficient spark plugs.
2. Description of the Related Art
Spark plugs are inserted in the head of an internal-combustion engine to ignite fuel mixtures. Prior art teaches spark plugs having a housing in which there is an insulator. A longitudinal bore is present within the insulator in which a center electrode is situated. In a typical spark plug, one, two, three, or four side electrodes are fixed to the housing.
By the application of an ignition voltage, a spark forms between the center electrode and one of the side electrodes. The spark between the side electrode and the center electrode runs along a longitudinal axis of the longitudinal bore of the insulator. Between the side electrode and the center electrode, a surface gap forms, which runs over the end face of the insulator facing the combustion chamber. The center electrode is situated fitting precisely into the longitudinal bore of the insulator, or has only a slight distance from the insulator.
Because of a carbon-fouled surface of the insulator, a so-called sliding discharge, that is, a discharge between housing and insulator, is favored specifically in the starting phase, since, during the starting phase, particularly high ignition voltages are present because of a lower intake-manifold vacuum, later ignition and lower intake temperature. Such a sliding discharge may lead to problems during ignition of the air/fuel mixture in the combustion chamber and may also cause ignition misfiring.
The instant invention remedies the above-mentioned problems that exist in the prior art spark plugs. The instant invention is a spark plug that comprises a terminal having a first end and a second end. The first end defines a distal end. A ceramic insulator has a third end and a fourth end. The third end extends from the second end. The ceramic insulator also has ribs that extend from the third end towards the fourth end but does not reach the fourth end. The ceramic insulator also has a shaft that extends from the ribs to the fourth end. The ceramic insulator also has an insulator that extends from the shaft and terminates at an insulator tip. Extending from the insulator tip is a central electrode post having a fifth end. Extending from the fifth end is a sidewall that terminates at a top wall.
This instant invention also comprises a shell that has a sixth end that extends from the fourth end. Extending from the sixth end is a nut, and extending from the nut is a body that has a face. Extending perpendicularly from the face are threads. This instant invention also comprises a ground electrode that has a circular wall that extends from the threads. The circular wall has a top rim. The top rim has a ridge that protrudes inwardly towards the center electrode post without contacting it. The ridge terminates at an interior face.
In the preferred embodiment, a first diameter of the insulator is smaller than a second diameter of the circular wall. A third diameter of the top wall is smaller than a fourth diameter of the interior face. The top wall protrudes beyond the top rim. Again, in the preferred embodiment, the ground electrode is made of platinum. In an alternate embodiment, the circular wall comprises at least one through hole.
It is therefore one of the main objects of the present invention to provide a spark plug comprising a ground electrode that has a circular wall that defines a more precise spark gap and spark.
It is another object of this invention to provide a spark plug comprising a ground electrode that has a circular wall that produces a more effective electric spark.
It is another object of this invention to provide a spark plug comprising a ground electrode that has a circular wall that reduces sliding discharge.
It is another object of this invention to provide a spark plug comprising a ground electrode that has a circular wall burns fuel mixtures that more effectively.
It is another object of this invention to provide a spark plug that does not require calibration as prior art spark plugs do.
It is yet another object of this invention to provide such a device that is inexpensive to manufacture and maintain while retaining its effectiveness.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.
With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which:
Referring now to the drawings, the spark plug of the instant invention is generally referred to with numeral 10. It can be observed that the preferred embodiment basically includes terminal 20, ceramic insulator 30, shell 50, and ground electrode 80.
Instant invention 10 pierces a wall of a combustion chamber, not seen, and therefore must also seal the combustion chamber against high pressures and temperatures, without deteriorating over long periods of time and extended use.
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In alternate embodiments, circular wall 84 comprises at least one through hole, such as through holes 100 in
In general, internal combustion engines can be divided into spark-ignition engines, which require spark plugs to begin combustion, and compression-ignition engines (diesel engines), which compress the air and then inject diesel fuel into the heated compressed air mixture where it auto-ignites. Compression-ignition engines may use glow plugs to improve cold start characteristics.
In operation, instant invention 10 is connected to high voltage generated by an ignition coil or magneto. As electrons flow from the ignition coil, a voltage difference generally develops between center electrode post 44 and circular wall 84. At this moment, no current can flow because fuel and air gases in gap 96 are an insulator, but as the voltage rises further it begins to change the structure of the fuel and air gases between center electrode post 44 and circular wall 84. Once the voltage exceeds a dielectric strength of the fuel and air gases, the fuel and air gases become ionized. The ionized fuel and air gas becomes a conductor and allows electrons to flow from across gap 96 to any area of circular wall 84, and more specifically, from sidewall 46 to interior face 86. This establishes an efficient spark and prolongs the life of instant invention 10.
As the current of electrons surges across gap 96, defining a spark, it raises the temperature to approximately 60,000 K. The intense heat in gap 96 causes the ionized fuel and air gas to expand very quickly, like a small explosion. The heat and pressure force the ionized fuel and air gas to react with each other, and at the end of this event, there should be a small ball of fire in gap 96 as the ionized fuel and air gases burn on their own. The size of this fireball or kernel depends on the exact composition of the mixture between the electrodes and the level of combustion chamber turbulence at the time of the spark.
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The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.
