PURPOSE: To obtain a highly precise and endurable titled detector, by a method wherein, in a knocking detector utilizing pulsation of cooling water, a piezoelectric element, adhered to a ceramic diaphragm, is used as a detecting means.
CONSTITUTION: A knocking detector 2 is fastened to a cylinder wall 6 by a screw part 202 so that one end thereof is exposed to a cooling system 12 surrounding an outer periphery of a cylinder wall of an engine 1, and a knocking detecting circuit 3 detects knocking from the output of the detector 2. A disc- shaped diaphragm 203 is supported to a cylindrical diaphragm retainer member 204, and they both consist of a ceramic sintered substance. An electrode 205, whereon silver paste is sintered, is formed at the back of the diaphragm 203, and a piezoelectric element 205, wherein electrodes consisting of silver paste are formed, is connected to the center of the back of the electrode 205 with a conductive adhesive 210. This enables obtaining of a knocking detector which has high-precision and durability.
OZAKI MAKOTO
OOTA MINORU
KONDOU KENJI
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