An in-cylinder pressure detection device which is capable of ensuring stable detection accuracy irrespective of tightening torque applied in mounting the in-cylinder pressure detection device and thermal expansion of component parts of the same. A housing ...

The drive circuit (10) applies a negative voltage to a glow plug (12) acting as a sensor and associated with the cylinder for an ion measurement device to determine the conductivity of combustion gases. The negative voltage is generated by a capacitor (20)...

A glow plug comprises a plug case, a plug body held in the plug case and a combustion pressure sensor. The plug case has a sealing face formed on an inner surface thereof. The plug body includes a housing having a sealing portion airtightly engaged onto th...

A glow plug comprises a cylindrical housing having an inward protrusion extending radially inwardly, a threaded portion for screwing the glow plug in an engine plug hole and a sealing portion in a front side of the male threaded portion for airtightly enga...

Ceramic heater (1) comprises an insulating ceramic substrate, a resistance heating element and an ion current detecting electrode portion. The detecting electrode portion has at least part of detecting face made of a nonmetallic conductive ceramic having a...

The method involves measuring an ion current (10) in a combustion chamber (1) of the engine and evaluating the resulting ion current measurement signal to detect the combustion process in the combustion chamber. The evaluation of the ion current measuremen...