Spark plug and cylinder head
View Patent ↗A spark plug comprises a spark plug body, which carries two electrodes bordering a spark gap at one end, and exhibits a nut with external thread that can rotate around the spark plug body. A cylinder head exhibits a rotational coding complementary to the rotational coding of the spark plug body.
1. A spark plug, comprising:
a spark plug body having a first end;
a rotational coding exhibited on the spark plug body;
a nut adapted to rotate around the spark plug body;
an external thread formed on the nut;
at least two electrodes carried by the first end and bordering a spark gap, and
a flange that limits an axial freedom of movement of the nut arranged on the spark plug body between the nut and a tip carrying the at least two electrodes.
2. The spark plug according to claim 1 , wherein a surface of the flange facing the tip carrying the at least two electrodes is flat and conical.
3. The spark plug according to claim 1 , wherein the rotational coding is formed on an edge of the flange.
4. The spark plug according to claim 1 , wherein the axial freedom of movement of the nut is limited on the spark plug body in two directions.
5. A cylinder head for an internal combustion engine, comprising:
a spark plug, comprising:
a spark plug body having a first end;
a rotational coding exhibited on the spark plug body;
a nut adapted to rotate around the spark plug body;
an external thread formed on the nut;
at least two electrodes carried by the first end and bordering a spark gap; and
a flange that limits an axial freedom of movement of the nut arranged on the spark plug body between the nut and a tip carrying the at least two electrodes; and
a fixture adapted to receive the spark plug; and
a second rotation coding exhibited on the fixture that is complementary to the rotational coding of the spark plug.
6. The cylinder head according to claim 5 , further comprising:
a high-potential electrode; and
a ground electrode extending from a root on the spark plug body over the high-potential electrode,
wherein the rotational coding and the second rotation coding only permit assembly of the spark plug in an orientation where the root and a fuel injection hole lie on different sides of the high-potential electrode.
7. The cylinder head according to claim 6 , wherein the ground electrode is a hook.
8. The cylinder head according to claim 6 , wherein a surface of the flange facing the tip carrying the at least two electrodes is flat and conical.
9. The cylinder head according to claim 6 , wherein the rotational coding is formed on an edge of the flange.
10. The cylinder head according to claim 6 , wherein the axial freedom of movement of the nut is limited on the spark plug body in two directions.