GLOW PLUG WITH COMBUSTION PRESSURE SENSOR

摘要

Disclosed is the structure of a glow plug with a combustion pressure sensor which includes a heater unit which is reduced in diameter stepwise. In the structure, the area of a member connecting the heater unit to a housing is made sufficiently large, so that the detection accuracy of the pressure sensor is improved. The structure can further improve the detection accuracy of the pressure sensor. The glow plug 100 includes a substantially cylindrical housing extending in an axial direction; a rod-shaped heater unit that has a front end protruding from the front end of the housing and is movable in the axial direction; a connecting member that connects the heater unit to the housing within the housing and allows the heater unit to move in the axial direction; and a pressure sensor that detects pressure received by the heater unit. The heater unit has a large-diameter portion formed at the rear end thereof and a small-diameter portion formed frontward of the large-diameter portion and having a diameter smaller than the diameter of the large-diameter portion. The connecting member connects the small-diameter portion of the heater unit to the housing within the housing.