| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a knocking sensor, configured such that an annular piezoelectric element is fitted around the shaft part of a main member in a held state between electrode plates, a nut is screwed into a screw formed in the outer peripheral surface of the shaft part, and an initial compression force is applied to a piezoelectric element between the nut and a flange on the end side of the shaft part, the method being capable of improving output characteristics without any change in density or structure of a weight and the flange or any change of a material such as a resin.SOLUTION: When a nut 71 for compressing a piezoelectric element 21 is screwed in, a lubricant is supplied to an engagement surface between the screw 73 of the nut 71 and the screw 15 of a shaft part 12. The presence of the lubricant reduces friction resistance in screwing-in. Thus, a fastening axial force of the screw is increased even with the same torque, thereby increasing the initial stress of the element 21. Thus, output characteristics are improved. |
