Knock sensor
AssigneeNippondenso Co., Ltd.
InventorsMasahito Imai, Kenji Kanemaru, Norio Kitao, Nobuyasu Gotou, Naohito Mizuno, Koichi Kamabora
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Abstract
A knock sensor for which a fabrication process is simple and moreover which can detect up to a high-frequency region is provided. A sensing element 11 composed of a semiconductor the weight (mass) thereof being 1 g or less and a signal processing circuit 11 are mounted on a fixing pedestal 9. The fixing pedestal 9 is fixed to a connector 2 side by means of adhesive or the like. Additionally, the connector 2 is fixed by means of caulking 16 of a housing 1. As a result thereof, the sensing element 11 is disposed within a space formed by the fixing pedestal 9 and the housing 1.
Claims31
A knock sensor, comprising:
- a housing installed on an engine;
- a connector portion assembled on said housing to form an isolated interior together with said housing, said connector portion including a lead electrically connecting between a side of said interior and side of an exterior of said knock sensor;
- a pedestal disposed within said isolated interior and having a resonant frequency of 40 kHz or more;
- and
- a sensing means fixed to said pedestal and having a weight of 1 g or less,
- said sensing means including a sensing element which has a frame part, a weight part set in said frame part and apart from said frame part, and a plurality of beam parts connecting said weight part with said frame part to doubly support said weight part within said frame part, wherein said frame part, said weight part and said beam parts are formed of semiconductor substance, and
- said sensing element including a detector detecting a vibration of said weight part responsive to a knocking occurring in said engine,
- wherein each of said beam parts has a geometry selected so as to make a resonant frequency of said sensing element 40 kHz or more to ensure that a maximum detection frequency of said detector is approximately 15 kHz.
A knock sensor, comprising:
- a housing installed on an engine;
- a connector portion assembled on said housing to form an isolated interior together with said housing, said connector portion including a lead electrically connecting between a side of said interior and a side of an exterior of said knock sensor;
- a sensor element located inside said interior, comprising a frame part, a weight part set in said frame part to be apart from said frame part, and a plurality of beam parts connecting said weight part with said frame part to doubly support said weight part within said frame part, wherein said frame part, said weight part and said beam parts are formed of semiconductor substance;
- and
- piezoresistance effect elements disposed on said beam parts, respectively, to detect a vibration of said weight part responsive to a knocking occurring in said engine,
- wherein each of said beam parts has a geometry selected so as to make a resonant frequency of said sensing element 40 kHz or more to ensure that a maximum detection frequency of said detector is approximately 15 kHz.
Dependencies are inferred from the claim text.