Spark plug and methods of manufacturing same
AssigneeFederal-Mogul Ignition Company
InventorWilliam J. Walker, Jr.
Life of this patent
Estimating the term…
Abstract
A spark plug and method of manufacturing, where the spark plug meets particular geometric relationships to maintain and potentially improve dielectric performance while downsizing other plug dimensions. The spark plug includes an insulator that can withstand higher voltages while having areas with a reduced cross-sectional thickness. In some embodiments, the insulator has a dielectric strength of 42 kV/mm or more with a radial thickness at the internal seal of 1.5 to 1.6 mm, inclusive, and a radial thickness at a gasket of 0.6 to 0.9 mm, inclusive.
Claims20
A spark plug, comprising:
- a shell having a thread area and an axial bore;
- an insulator having a ceramic body and an axial bore, the insulator disposed at least partially within the axial bore of the shell, the ceramic body being made from a ceramic material;
- a gasket disposed at least partially within the axial bore of the insulator;
- an internal seal disposed at least partially within the axial bore of the insulator;
- a center electrode disposed at least partially within the axial bore of the insulator;
- and
- a ground electrode configured to create a spark gap with the center electrode,
- wherein
- (
- T
- IS
- D
- C
-
- E
- )
-
- (
- D
- S
- D
- M
- )
-
- (
- ρ
- T
-
- H
- ρ
- T
-
- H
- -
- ρ
- )
- 0
- .
- 5
- >
- 2
- or
- (
- T
- G
- D
- C
-
- E
- )
-
- (
- D
- S
- D
- M
- )
-
- (
- ρ
- T
-
- H
- ρ
- T
-
- H
- -
- ρ
- )
- 0
- .
- 5
- >
- 2
- where TIS is a radial thickness of the insulator at the internal seal, DCE is a diameter of the center electrode, Ds is a diameter of the internal seal, DM is a major diameter at the thread area of the shell, ρTH is a density of the ceramic material that is fully dense and pore-free, ρ is a density of the ceramic material, and TG is a radial thickness of the insulator at the gasket.
A spark plug, comprising:
- a shell having an axial bore, the shell having an M12 major diameter at a thread area of the shell;
- an insulator having a ceramic body and an axial bore, the insulator disposed at least partially within the axial bore of the shell;
- an internal seal disposed at least partially within the axial bore of the insulator;
- a center electrode disposed at least partially within the axial bore of the insulator;
- and
- a ground electrode configured to create a spark gap with the center electrode,
- wherein the insulator has a dielectric strength of 42 kV/mm or more and a radial thickness at the internal seal of 1.5 to 1.6 mm, inclusive.
A spark plug, comprising:
- a shell having an axial bore, the shell having an M10 major diameter at a thread area of the shell;
- an insulator having a ceramic body and an axial bore, the insulator disposed at least partially within the axial bore of the shell;
- a gasket disposed at least partially within the axial bore of the shell;
- a center electrode disposed at least partially within the axial bore of the insulator;
- and
- a ground electrode configured to create a spark gap with the center electrode,
- wherein the insulator has a dielectric strength of 42 kV/mm or more and a radial thickness at the gasket of 0.6 to 0.9 mm, inclusive.
Dependencies are inferred from the claim text.