Ngk Spark Plug Company, Limited

Katsuki Aoi

Tomohiro Hirata

Sadamitsu Harada

Yasuo Ito

Noriaki Kondo

Shingo Ito

Daisuke Tahira

Hiroyuki Kuno

Takashi Maeda

Provided is a knocking sensor with a support member, a piezoelectric element, a pair of electrode parts, a resistor and a case. The resistor has a resistor body formed with a metal film and connected in parallel to the pair of electrode parts. The resistor also has an outer coating film applied to cover the metal film. The outer coating film is formed of a resin material having a higher thermal deformation temperature than that of a resin material of the case.

Knocking sensor

A non-resonant knock sensor includes: a sensor body having a metal shell provided with a shell-side cylindrical portion and a shell-side flange portion, a piezoelectric element, a weight arranged to hold the piezoelectric element between the shell-side flange portion and the weight and a fixing member having a third through hole through which the shell-side cylindrical portion is inserted and being arranged to press the weight toward the shell-side flange portion and thereby fix the weight in position; and a resin molded part. The fixing member has formed therein flow paths for introducing a resin into an inner space between the shell-side cylindrical portion and the piezoelectric element. The flow paths are provided in the form of at least one of being connected to the third through hole and being separated from the third through hole and are formed intermittently in a circumferential direction of the fixing member.

Non-resonant knock sensor

In a knocking sensor, including: a metal shell having a cylindrical portion, and a flange portion that is located on the cylindrical portion, and projected toward an outside of the cylindrical portion in a circumferential direction, an annular weight that is fitted onto an outer circumference of the cylindrical portion, and has an upper surface, an annular piezoelectric element that is fitted onto an outer circumference of the cylindrical portion, and interposed between the flange portion and the weight, and an insulating body that is interposed between the flange portion and the piezoelectric element, a protruding portion that is protruded while being plastically deformed from an inner surface of the cylindrical portion outward in a circumferential direction, and locks the weight in contact with the upper surface of the weight directly or through a member is disposed on an outer circumferential surface of the cylindrical portion.

A non-resonant knocking sensor including a sensor body including: a metal shell having a shell-side cylindrical section, a piezoelectric element, a weight and a fixing portion having a fixing-side cylindrical section; and a resin molded body. The fixing-side cylindrical section includes crimped portions to be crimped and spaced-apart portions which are spaced apart from the shell-side cylindrical section, and a space between the outer circumferential surface of the shell-side cylindrical section and an inner circumferential surface of the spaced-apart portions are filled with the resin. Also disclosed is a method for producing the non-resonant knocking sensor.

Non-resonant knocking sensor and method for producing the same

A knocking sensor which includes: a piezoelectric element; a support member having a support body portion, the support body portion including a support surface directly or indirectly supporting the piezoelectric element; and a resin coating covering the piezoelectric element and at least a part of the support member, the resin coating having an outside portion covering an outer circumference of the piezoelectric element and an outer circumference of the support body portion. The support body portion of the support member has a first engagement portion on the base end side thereof. The resin coating has a curved portion which extends from the outside portion toward the interfacial direction inner side, and curves toward the base end side of the support body portion. Further, the curved portion includes a second engagement portion which engages the first engagement portion.

A knock sensorfor attachment to an internal combustion engine. The knock sensorincludes a capand a support member. At least a part of the top surface of the support memberis covered by capto prevent a mounting boltfrom directly making contact with the top surface of the support memberwhen the mounting boltextends through a through-holein the sensor. The capcovers the top surface of the support memberto protect the support member from being ground or abraded by the mounting bolt

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 non-resonance type knock sensor is provided which comprises a support member having a main body portion in the form of a hollow post and a radially outward flange portion at an axial end of the main body portion, the main body portion having an abutment at an outer circumferential periphery thereof, a piezoelectric element having a hole through which the main body portion extends and placed on the flange portion, a weight having a hole through which the main body portion extends and placed on the piezoelectric element, and an elastic device disposed between the abutment and the weight to produce an elastic force for pressing the weight and the piezoelectric element against the flange portion and thereby fixing the weight and the piezoelectric element to the support member.

Non-resonance type knock sensor

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.

Growing community of inventors

Kani, Japan

Katsuki Aoi