| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a knocking sensor excellent in insulating property even at operating temperatures not lower than 150°C, and excellent in the accuracy of knocking detection. <P>SOLUTION: The knocking sensor 10 includes: a sensor body 20 which has metal fittings 12 of the body including a cylindrical part 12a and a collar part 12b located at one end of this cylindrical part 12a while projecting towards the outside in the radial direction, an annular piezoelectric element 15, an upper electrode plate 16 and a lower electrode plate 14 lapped on the top surface and the lower surface of the piezoelectric element 15, a weight 17 interposing the piezoelectric element 15 with the collar part 12b together therebetween, a lower insulating plate 13 disposed between the collar part 12b and the lower electrode plate 14, and an upper insulating plate 13t disposed between the upper electrode plate 16 and the weight 17; and a resin molding 11 for covering the sensor body 20. Each thickness of the upper insulating plate 16 and the lower insulating plate 14 is within a range of 0.05 to 0.50 mm, and the resin molding 11 is composed of polyphenylene sulfide excellent in heat resisting property. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
