Patent ID: 7004009
Filing Date: 2006-02-28
Classification: G01L

Abstract:
1. A knocking sensor for an internal combustion engine, comprising: a base member including a cylindrical part and a flange part formed at its one end; an annular combination member including at least an annular piezoelectric element and an annular weight, and disposed at an outer periphery of the cylindrical part of the base member; a pressure fastening member for pressure-fastening the annular combination member to the flange part of the base member; and a resin mold member covering the annular combination member and the pressure fastening member, wherein an annular space is provided between the annular combination member and the cylindrical part of the base member, the resin mold member is filled also in the annular space, the annular weight has only two communicating passages extending in its diameter direction, the two communicating passages are disposed at positions separate from each other by substantially 180 degrees with respect to a center axis of the annular weight, and each of the two communicating passages connects an outer periphery of the annular weight and the annular space to make passage for filling the resin material into the annular space.