Mechanical ignition sensor

摘要

A mechanical ignition sensor which can reduce rotational resistance of a trigger lever (34). An inner periphery of a slit (41) on the side of a spring (32) is formed into an inclined surface (41A) which is an abutment surface with an outer peripheral side of the slit opened. An inclined surface (40A) of a slide holding portion (40) is formed as a curved surface along a locus of rotation of an abutment leading end portion of the slide holding portion. An angle of inclination ( alpha ) of an abutment leading end (P) of an inertial mass body (30) with respect to an axial direction of the mechanical ignition sensor is set small such that only the abutment leading end (P) abuts against the inclined surface (40A) of the slide holding portion (40). As a result, sliding resistance between the inclined surface (41A) of the slit and the inclined surface (40A) of the slide holding portion becomes smaller. Further, an end portion (32B) of the spring (32) is inserted into a ring groove (35) having a semicircular cross-sectional configuration, formed at a transverse-directional central portion of an end surface (30A) of the inertial mass body (30). <MATH>