Ngk Spark Plug Company, Limited

Tomohiro Hirata

Katsuki Aoi

Takeshi Mitsuoka

Yasuo Ito

Kazushige Ohbayashi

Katsuya Yamagiwa

Masato Yamazaki

Yukihiro Hamaguchi

Takuma Nomura

Sadamitsu Harada

Takashi Maeda

Hideaki Hiramitsu

Manabu Horiguchi

Ryotaro Tawara

There is provided a knocking sensor that has good insulation characteristics even at an operating temperature of 150&#xb0; C. or more and is excellent in the accuracy of knocking detection. The knocking sensorincludes a sensor bodyincluding: a metal shellthat includes a cylindrical portionand a flange portionpositioned at one end of the cylindrical portionand protruding outward in a radial direction; an annular piezoelectric element; upper and lower electrode platesandthat are superimposed on upper and lower surfaces of the piezoelectric element; a weightthat is disposed so that the piezoelectric elementis interposed between the weight and the flange portion; a lower insulating platethat is disposed between the flange portionand the lower electrode plate; and an upper insulating platethat is disposed between the upper electrode plateand the weight; and a resin moldingthat covers the sensor body. Further, the thickness of each of the upper and lower insulating platesandis in the range of 0.05 mm to 0.50 mm, and the resin moldingis made of polyphenylene sulfide having good heat resistance.

Knocking sensor

A piezoceramic material according to an embodiment of the present invention has a composition represented by Pb{ZrTiSn(SbNb)}Owhere 1.000&#x2266;m&#x2266;1.075, 0.470&#x2266;x&#x3c;0.490, 0.020&#x2266;y&#x2266;0.040, 0&#x3c;n&#x3c;1.000 and 0&#x3c;z&#x2266;0.025 and a crystallite size of 30 to 39 nm.

Piezoceramic material, piezoelectric element and non-resonance knock sensor

A knocking sensor comprises: a cylindrical body including a cylindrical portion and a supporting flange provided at an outer circumference of a lower end of the cylindrical portion; parts including an insulating member, an electrode plate and an annular piezoelectric element; and a fixing member including a tubular portion which comprises a holding portion protruding from an outer circumference of the tubular portion and is formed to insert into the cylindrical portion from an upper end of the cylindrical portion, the holding portion being elastically deformable to hold the parts, wherein the fixing member is fixed in the cylindrical portion by inserting the tubular portion into the cylindrical portion from the upper end of the cylindrical portion and wherein the parts are clamped and fixed between the supporting flange and the holding portion by holding the parts elastically with the holding portion, while the fixing member is fixed in the cylindrical portion.

A knock sensor comprises a sensor body having a metallic shell including a cylindrical portion and a flange portion formed at an end of the cylindrical portion, an annular piezoelectric element fitted around the cylindrical portion and an annular weighting member fitted around the cylindrical portion to hold the piezoelectric element between the weighting member and the flange portion, and a resin-molded sensor casing arranged circumferentially around the sensor body. The resin-molded sensor casing includes a weighting portion located nearer to the weighting member than to the piezoelectric element with respect to an axial direction of the cylindrical portion, and at least the weighting portion of the resin-molded sensor casing is made of a resin containing at least one of metal powder and metal oxide powder and has a density of 2.0 g/cm or higher.

Nonresonant type knock sensor

Growing community of inventors

Komaki, Japan

Tomohiro Hirata