Patent ID: 9366594
Filing Date: 2016-06-14
CPC Classification: G01L

Claim Text:
1. A combustion pressure sensor comprising: a tubular housing having an axial hole extending in a direction of an axis; a flexible member disposed within the axial hole and fixed at one end to the housing, the flexible member being displaceable and contractable along the direction of the axis; a rod-shaped pressure transmission body inserted into the axial hole and fixed, through its outer circumferential surface, to the other end of the flexible member, the pressure transmission body having a front end portion exposed to the outside; and a sensor element fixed directly or indirectly to the housing and outputting a signal on the basis of a pressure applied thereto from the pressure transmission body, wherein the housing includes a main body portion having, on its outer circumferential surface, a screw portion for screw engagement with a mounting hole of an internal combustion engine, and a cap member joined to a front end portion of the main body portion and having a press contact portion which is press-contacted with the internal combustion engine when the screw portion is screwed into the mounting hole of the internal combustion engine; and the one end of the flexible member is fixed to the main body portion, the combustion pressure sensor being characterized in that a relation A<B is satisfied where A represents an amount of compression per unit length along the axis of the main body portion and B represents an amount of compression per unit length along the axis of the cap member, the compression amounts being measured when a force along the axis is applied to the housing.