Patent ID: 7836753

Claim:
A knock sensor, comprising: a base including a cylinder section, a flange section formed at one end of the cylinder section and a through-hole passing through the cylinder section and the flange section; annular constituent parts for the knock sensor including an annular piezoelectric element, terminal plates through which an output signal is taken out from electrodes of the piezoelectric element, annular insulation sheets, and an annular weight, the annular constituent parts being inserted onto the cylinder section of the base; a pressing member for pressing the annular constituent parts onto the flange section of the base; and a resin mold including a first cylindrical mold section that encloses the base, the annular constituent parts and the pressing member, and a connector section that encloses a terminal or lead-wire lead-out section for connecting the terminal plates to outside equipment and is integrally injection-molded at one time with the first cylindrical mold section, protruding from a side thereof; wherein the resin mold is formed using an injection gate, located at a position corresponding to a position on a circumference of the first cylindrical mold section excluding a portion thereof opposing the connector section, which forms a predetermined angle with respect to a center line connecting a center of the connector section with that of the through-hole of the base.