Patent ID: 7201038
Filing Date: 2007-04-10
Classification: G01L,G01P

Abstract:
1. A knock sensor comprising: a metal base comprising a disk-shaped flange portion and a tubular portion extending axially from said flange portion, and provided with a through hole running through both of said flange portion and said tubular portion; an annular piezoelectric element; a terminal plate; an insulating sheet and a weight that are fitted onto the tubular portion of said base; a groove part on an outer circumferential surface of said tubular portion; and a stopper ring which applies an axial preload to said weight disposed on said tubular portion, wherein said stopper ring is fixedly caulked into said groove part, such that said stopper ring has a portion, which is recessed into said groove part, with an outer diameter which is less than an outer diameter of said stopper ring at an area above or below said portion recessed into said groove part.