Abstract: A knock sensor includes: a base made up of a flange portion, and a tube portion; a sensor main body including a piezoelectric element that is fitted over an outer peripheral portion of the tube portion; and a stopper ring that is fitted over the outer peripheral portion of the tube portion and cooperates with the flange portion to clamp the sensor main body, a groove being formed on the outer peripheral surface of the tube portion, and the knock sensor being fixed by driving a pressing jig into an outer peripheral surface of the stopper ring to plastically deform the stopper ring and press a protruding portion into the groove, wherein: an axial length of a recess portion that is formed simultaneously on the outer peripheral surface of the stopper ring when the protruding portion is formed is longer than an axial length of the groove.

Abstract: A knock sensor includes: a base including an annular flange portion and a cylindrical portion, an annular piezoelectric element fitted onto the cylindrical portion, electrode portions oppositely formed on front and rear surfaces of the annular piezoelectric element, first and second terminal plates in contact with the electrode portions, an annular weight, a first insulating sheet interposed between the first terminal plate and the flange portion, a second insulating sheet interposed between the second terminal plate and the weight. The electrode portions include annular partial electrodes each having a width narrower than a radial width of the piezoelectric element. The annular partial electrode has a thickness d satisfying: L/d<80 where L is a radial dimension of outer circumferences of the front and rear surfaces where the electrode portions are not arranged.

Abstract: A knock sensor includes: a base including an annular flange portion and a cylindrical portion, an annular piezoelectric element fitted onto the cylindrical portion, electrode portions oppositely formed on front and rear surfaces of the annular piezoelectric element, first and second terminal plates in contact with the electrode portions, an annular weight, a first insulating sheet interposed between the first terminal plate and the flange portion, a second insulating sheet interposed between the second terminal plate and the weight. The electrode portions include annular partial electrodes each having a width narrower than a radial width of the piezoelectric element. The annular partial electrode has a thickness d satisfying: L/d<80 where L is a radial dimension of outer circumferences of the front and rear surfaces where the electrode portions are not arranged.

Abstract: A knock sensor includes: a base made up of a flange portion, and a tube portion; a sensor main body including a piezoelectric element that is fitted over an outer peripheral portion of the tube portion; and a stopper ring that is fitted over the outer peripheral portion of the tube portion and cooperates with the flange portion to clamp the sensor main body, a groove being formed on the outer peripheral surface of the tube portion, and the knock sensor being fixed by driving a pressing jig into an outer peripheral surface of the stopper ring to plastically deform the stopper ring and press a protruding portion into the groove, wherein: an axial length of a recess portion that is formed simultaneously on the outer peripheral surface of the stopper ring when the protruding portion is formed is longer than an axial length of the groove.

Abstract: A knock sensor of the invention includes a base having a cylindrical part mounted on a vibration generating part and a flange part, an annular piezoelectric element fitted to the cylindrical part and for converting a knocking vibration of the vibration generating part into an electric signal to detect it, electrodes respectively provided to be in contact with both surfaces of the piezoelectric element, terminal plates disposed to be in contact with the respective electrodes and for extracting an output of the piezoelectric element to outside, and a hold unit for pressure holding the piezoelectric element, the electrodes and the terminal plates to the flange part, in which a conductive adhesive material having an almost equal thickness to the electrode is provided on a portion of the piezoelectric element which is not in contact with the electrode.

Abstract: A stacked body constituted by a first insulating sheet, a first terminal plate, a piezoelectric element, a second terminal plate, a second insulating sheet, a weight, and a disk spring is fitted over a cylindrical portion of a base, clamped and held between a nut and a flange portion of the base, and resin-molded. Annular partial electrodes having a width narrower than a radial width of the piezoelectric element are formed on front and rear surfaces of the piezoelectric element. The first and second terminal plates have annular portions formed so as to have annular shapes having an outside diameter and an inside diameter substantially equal to those of the partial electrodes, and are stacked such that the annular portions are placed in close contact with entire surfaces of the partial electrodes.

Abstract: A knock sensor of the invention includes a base having a cylindrical part mounted on a vibration generating part and a flange part, an annular piezoelectric element fitted to the cylindrical part and for converting a knocking vibration of the vibration generating part into an electric signal to detect it, electrodes respectively provided to be in contact with both surfaces of the piezoelectric element, terminal plates disposed to be in contact with the respective electrodes and for extracting an output of the piezoelectric element to outside, and a hold unit for pressure holding the piezoelectric element, the electrodes and the terminal plates to the flange part, in which the electrodes are provided to be in partial contact with the piezoelectric element, and an electric insulating material having an almost equal thickness to the electrode is provided on a portion of the piezoelectric element which is not in contact with the electrode.

Abstract: A stacked body constituted by a first insulating sheet, a first terminal plate, a piezoelectric element, a second terminal plate, a second insulating sheet, a weight, and a disk spring is fitted over a cylindrical portion of a base, clamped and held between a nut and a flange portion of the base, and resin-molded. Annular partial electrodes having a width narrower than a radial width of the piezoelectric element are formed on front and rear surfaces of the piezoelectric element. The first and second terminal plates have annular portions formed so as to have annular shapes having an outside diameter and an inside diameter substantially equal to those of the partial electrodes, and are stacked such that the annular portions are placed in close contact with entire surfaces of the partial electrodes.

Abstract: A knock sensor of the invention includes a base having a cylindrical part mounted on a vibration generating part and a flange part, an annular piezoelectric element fitted to the cylindrical part and for converting a knocking vibration of the vibration generating part into an electric signal to detect it, electrodes respectively provided to be in contact with both surfaces of the piezoelectric element, terminal plates disposed to be in contact with the respective electrodes and for extracting an output of the piezoelectric element to outside, and a hold unit for pressure holding the piezoelectric element, the electrodes and the terminal plates to the flange part, in which the electrodes are provided to be in partial contact with the piezoelectric element, and an electric insulating material having an almost equal thickness to the electrode is provided on a portion of the piezoelectric element which is not in contact with the electrode.

Abstract: There is provided a knocking sensor for an internal combustion engine improved so that electrical damage of a terminal plate in an annular combination member is more certainly prevented. Only two communicating passages separate from each other by substantially 180 degrees are formed in an annular weight of the annular combination member, and resin is filled into an annular space at an inner periphery of the annular combination member by using these two communicating passages. When a passage axis where the two communicating passages are positioned is made substantially orthogonal to a resin injection direction, the resin can be more effectively filled into the annular space.

Abstract: There is provided a knocking sensor for an internal combustion engine improved so that electrical damage of a terminal plate in an annular combination member is more certainly prevented. Only two communicating passages separate from each other by substantially 180 degrees are formed in an annular weight of the annular combination member, and resin is filled into an annular space at an inner periphery of the annular combination member by using these two communicating passages. When a passage axis where the two communicating passages are positioned is made substantially orthogonal to a resin injection direction, the resin can be more effectively filled into the annular space.

Abstract: A knock sensor of the invention includes a base having a cylindrical part mounted on a vibration generating part and a flange part, an annular piezoelectric element fitted to the cylindrical part and for converting a knocking vibration of the vibration generating part into an electric signal to detect it, electrodes respectively provided to be in contact with both surfaces of the piezoelectric element, terminal plates disposed to be in contact with the respective electrodes and for extracting an output of the piezoelectric element to outside, and a hold unit for pressure holding the piezoelectric element, the electrodes and the terminal plates to the flange part, in which the electrodes are provided to be in partial contact with the piezoelectric element, and an electric insulating material having an almost equal thickness to the electrode is provided on a portion of the piezoelectric element which is not in contact with the electrode.

Abstract: A rotation sensor device capable of detecting rotation speed of a rotatable magnetic member with high accuracy and reliability even in a low rotation speed range and a method of manufacturing the same through simplified process. As a means for detecting a rotation frequency of a toothed-wheel-like rotatable magnetic member (100), a permanent magnet (25) and a magneto-electric conversion element (22) are used. Conductors (24) having these elements (22; 25) mounted at a tip end portion is embedded integrally in a base (23) of a resin material through an insert molding process such that the elements (22; 25) and those portions of the conductors which constitute mounting electrodes are exposed at least partially on the surface of the base (23). Electronic parts (26) are packaged on the mounting electrode portions (24a).