| 摘要 |
<p>A knocking sensor is provided which, even at an operating temperature of 150°C or higher, exhibits satisfactory insulation characteristics and excellent knocking detecting characteristics. The knocking sensor includes: a sensor body 10 including: a metal shell 11 including, a tubular portion 11A and a flange portion 11B, a piezoelectric element 14, a weight 17 which is placed so as to sandwich the piezoelectric element 14 with the flange portion 11A, a flange portion-side electrode plate 13 which is placed between the piezoelectric element 14 and the flange portion 11B, a weight-side electrode plate 15 which is placed between the piezoelectric element 14 and the weight 17, a flange portion-side insulating plate 12 which is placed between the flange portion 11B and the flange portion-side electrode plate 13, and a weight-side insulating plate 17 which is placed between the weight 17 and the weight-side electrode plate 15; and a resin molded body 30 which covers the sensor body 10. The resin molded body 30 is made of PPS. The flange portion-side insulating plate 12 and the weight-side insulating plate 16 are made of a resin that does not contain ester bond. A change of sensor capacitance depending on the temperature is suppressed, and decrease in accuracy of detection of knocking is suppressed.</p> |
