Spark plug
US9306375B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 2013 |
| Grant date | Apr 5, 2016 |
| Priority date | — |
| Expiry date | May 7, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/36
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug includes a center electrode, an insulator, a metallic shell, and a seal member for providing a seal between the insulator and the metallic shell. The insulator includes a first portion, a second portion located axially forward of the first portion and being smaller than the first portion, and an insulator first-diameter-reducing-portion whose outside diameter reduces forward and which connects the first portion and the second portion. The metallic shell includes a protrusion that includes a metallic shell diameter-reducing-portion whose inside diameter reduces forward. The seal member is disposed between the insulator first-diameter-reducing-portion and the metallic shell diameter-reducing-portion. A relationship θ21>θ22 is satisfied, where the angle θ21 is an angle between a straight line orthogonal to the axial line and the outline of the metallic shell diameter-reducing-portion, and the angle θ22 is an angle between the straight line and an outline of the insulator first-diameter-reducing-portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.