Spark ignition device with in-built combustion sensor

摘要

A spark plug having an integral gasoline combustion sensor is disclosed. The spark plug includes a center electrode assembly with a terminal stud at one end and a center electrode with a sparking surface at an opposite end; a generally tubular insulator surrounding the center electrode assembly; a shell surrounding the insulator and having along its length a turn-over on a first end, a barrel having an outer surface and barrel shoulder on a gasket flange thereof, a threaded portion, and a ground electrode; and a piezo sensor assembly located on the barrel shoulder proximate the outer surface of the barrel which includes a lower electrode contact, a piezo transducer, an upper electrode contact, an isolator having a convex upper surface, and an upper bushing which is attached to the barrel.

主权项

1. A spark plug, comprising:
a center electrode extending along a center axis and with a sparking surface at an end; a generally tubular insulator surrounding said center electrode and including at least one shoulder; a shell surrounding said insulator and having a turn-over on a first end, said first end being an extreme distal end of said shell, and said turn-over extending inwardly toward said center axis and along said shoulder of said insulator; said shell including a gasket flange presenting a gasket seat for engaging a gasket and presenting a barrel shoulder facing opposite said gasket seat; said shell further including a barrel extending from said barrel shoulder to said turn-over, a threaded portion, and a ground electrode; wherein said turn-over, said barrel having said outer surface and said barrel shoulder, said gasket flange, and said threaded portion of said shell are integrally formed; and a piezo sensor assembly located on said barrel shoulder between said barrel shoulder and said turn-over, said piezo sensor comprising a lower electrode contact, a piezo transducer, an upper electrode contact, an isolator, and an upper bushing which is attached to said barrel.