Electric lamp and discharge devices – Spark plugs – Particular electrode structure or spacing
Reexamination Certificate
1999-11-08
2002-04-02
Patel, Ashok (Department: 2879)
Electric lamp and discharge devices
Spark plugs
Particular electrode structure or spacing
C313S142000
Reexamination Certificate
active
06366007
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an ignition sparking plug, wherein the end of the grounding electrode in the ignition sparking plug near the central electrode is manufactured as a tip end so as to reduce the area in the central electrode to be shielded by the grounding electrode. Therefore, as the ignition sparking plug is used, the mixed gas within the cylinder can be burned rapidly, meanwhile, the material used is saved.
BACKGROUND OF THE INVENTION
With reference to
FIG. 1
, the ignition sparking plug
10
is assembled in the cylinder
11
. By discharging between the central electrode
12
at one end thereof and the grounding electrode
13
, an electric spark is generated so as to combust the mixing gas (formed by oil and air) in the cylinder
11
to cause an explosion. Therefore, the piston
110
is pushed away.
In practical operation, in two strokes of the engine, all the cylinders
11
must be operated one time. For an operation of 3000 revolutions per minutes (rpm), the engine revolves through 50 circles per second. In other words, each cylinder moves 25 times in each second. Thus, it should be understand that the actuation time of the ignition sparking plug is very short. In order that the explosion of the ignition sparking plug is more practical and is pushed smoothly, the mixing gas must enter into the space between the central electrode
12
and the grounding electrode
13
in a very short time (before explosion, the space within the cylinder is in a vacuum state, thus mixed gas necessarily enters into the space, and is ignited in the space between the central electrode and the grounding electrode). However, in general, the grounding electrode
13
of an ignition sparking plug
10
is a flat plate which shield the central electrode
12
completely. Thus, the mixed gas is very difficult to enter into the space between the central electrode
12
and the grounding electrode
13
in a very short time. As a result, the function of the ignition sparking plug
10
and the action of the cylinder
11
are affected. Therefore, many improvements are performed for improving such kind of prior art ignition sparking plug.
With reference to
FIGS. 2 and 3
, wherein a cruciform trench
14
or a V shape trench
15
is formed in the central electrode
12
so as to increase the space connected the central electrode
12
and the grounding electrode
13
. Thus, by this enlarged space, the mixed gas can flow this space rapidly. Referring to
FIG. 4
, a trench
16
is formed at the inner surface of the grounding electrode
13
with respect to the central electrode
12
so as to increase the space between the central electrode
12
and the grounding electrode
13
. Thus, mixed gas may enter into this space. Besides, referring to
FIG. 5
, the grounding electrode
13
is made with a shorter length for reducing the shielding of the central electrode
12
so that mixed gas enters into the space between the central electrode
12
and the grounding electrode
13
rapidly for explosion. With reference to
FIG. 6
, a hole
17
is drilled in the grounding electrode
17
with respect the central electrode
12
so that mixed gas can enter into the space between the central electrode
12
and the grounding electrode
13
rapidly for next explosion.
The above improvements is aimed at the mixed gas may enter into a predetermined space. However, in above designs, the grounding electrode
13
still shields the central electrode
12
with a large area. Moreover, due to the width of the grounding electrode
13
, the mixed gas
13
must move around the two sides of the grounding electrode
13
for entering into the space between central electrode
12
and the grounding electrode
13
. Similarly, the firing mixed gas must flow around the two sides of the grounding electrode
13
for extending the combustion outwards. Therefore, the traveling of the mixed gas is not straight. In a short ignition, the explosion of the mixed gas will not be smooth, therefore, although the aforesaid improvements have the effect of improving the function of the prior art ignition sparking plug
10
, the effect is not preferred.
Besides, when the ignition sparking plug
10
is ignited to spark, since the area of the grounding electrode
13
is too large, it will absorb a larger thermal energy and the expansion of the spark is prevented. As a result, the range of the spark is hindered. Furthermore, when cool mixed gas enters into the space, the surface of the ignition sparking plug
10
will be cooled so that the surfaces of the central electrode
12
and grounding electrode
13
have no function of ignition. Therefore, a grounding electrode designed with a larger area can not improve the performance of the ignition. As oil only occupies a small part of the mixed gas, it is possible that no explosion occurs. Accordingly, the air gate must be closed for increasing the concentration of the oil. This not only wastes oil, but also an incomplete combustion occurs and coal will accumulate. Therefore, aforesaid ignition sparking plug is not met the practical requirement and is necessary to be improved further.
SUMMARY OF THE INVENTION
Accordingly, the primary object of the present invention is to provide an improved structure of an ignition sparking plug having a grounding electrode and a central electrode. The grounding electrode has a tip end with respect to the central electrode so that the only a small part of the central electrode is shielded by the grounding electrode. Thereby, mixed gas enters into the space between the grounding electrode and the central electrode rapidly so as to be ignited and then explode quickly to push the piston. Therefore, the piston can move reciprocally. Since the grounding electrode has a smaller volume, the generated spark has a large volume and absorbs a little thermal energy. Since electric discharging occurs in a tip point, the efficiency of ignition is high so as to improve the air to oil ratio in the cylinder and thus oil is saved and exhausted waste is reduced.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.
REFERENCES:
patent: 4700103 (1987-10-01), Yamaguchi et al.
patent: 5650687 (1997-07-01), Van Den Bogaert
patent: 5821676 (1998-10-01), Atchinson, II et al.
patent: 09260025 (1997-10-01), None
patent: 11121142 (1997-10-01), None
Baxley Charles E.
Patel Ashok
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