Patent ID: 7107819
Filing Date: 2006-09-19
Classification: F02D,F02P,G01L,H01T

Abstract:
1. A pressure sensor unit ( 1 , 200 , 210 , 220 , 230 ) in which a ring-like pressure sensing element ( 3 ) is incorporated in a cylindrical unit body portion ( 2 ) having a spark plug insertion hole ( 4 ) formed in a bottom surface thereof, the pressure sensing element ( 3 ) surrounding the spark plug insertion hole ( 4 ); when a side where the pressure sensing element ( 3 ) is located in a direction of an axis (O) is set as a front end side, the unit body portion ( 2 ) is inserted into and fixed to a plug hole (PH) from the front end side in the direction of the axis (O); and in that state, a spark plug ( 100 ) is inserted into the spark plug insertion hole ( 4 ) to be thereby attached to an attachment hole (PF) at a bottom of the plug hole (PH), so that the pressure sensing element ( 3 ) is nipped and retained between a sensor support portion ( 102 ) projecting like a collar from an outer circumferential surface of a metal shell ( 101 ) of the spark plug ( 100 ), and an opening circumferential edge portion (GS) of the attachment hole (PF); wherein the pressure sensing element ( in a state where the spark plug (