| 摘要 |
PURPOSE: A knock sensor is provided to minimize malfunctions of the knock sensor and exactly detects vibrations of an engine by preventing deformation of a lower part of an elastic member of a mass even an upper part of the mass is plastically deformed. CONSTITUTION: A knock sensor comprises a sensor body(11), a mass(31), and piezoelectric elements(51). The sensor body comprises a joining portion(17) and a moving space(21). The joining portion having a recess portion is formed on an upper part of an outer surface. The moving space is formed under the joining portion at a predetermined interval. The mass comprises a pressure-deformable portion(33) and an elastic portion(35). The pressure-deformable portion is coupled to the joining portion with the plastic deformation. The elastic portion is extended from the pressure-deformable portion and placed oppositely to the moving space. The piezoelectric elements are placed in a lower part of the sensor body and contacted with a bottom of the mass through an electrode(53). |
