Abstract: A bracket recessed portion of a bracket is inserted into a vehicular jig recessed portion of a vehicular jig, and a washer is put on a face of the bracket through an elastic member on a side opposite from a contact face of the bracket contacting the vehicular jig. The bracket is fixed by inserting a screw into a washer screw hole, an elastic member screw hole, a bracket screw hole and an attachment member screw hole from a side of the washer opposite from a contact face of the washer contacting the bracket. Thus, vibration of the bracket can be damped economically.

Abstract: An ultrasonic element has a membrane formed as a thin walled portion of a substrate, on which a piezoelectric vibrator is formed. The piezoelectric vibrator comprises a piezoelectric thin film and metal electrode films, which are formed into a sandwiched structure. The piezoelectric vibrator resonates with the membrane at a predetermined ultrasonic wave-band frequency. A hollow-out pattern is formed in the piezoelectric thin film to divide the piezoelectric vibrator into multiple portions, wherein the hollow-out pattern is formed in such an area corresponding to stress concentrated area which appears in vibrations of the membrane in diametrical directions thereof. The membrane is made to be easily deformed in response to vibration of the piezoelectric vibrator, so that an ultrasound of a higher sound pressure can be emitted.

Abstract: A current sensor includes a first magnetic core that surrounds a portion of a conductor as a current path and has gaps therein, each of which is defined by adjacent ends spaced from each other by a first distance, a magnetic sensing element placed in at least one of the gaps, and a second magnetic core placed near the surrounded portion of the conductor to divide the conductor into channels. The second magnetic core is spaced from the first magnetic core by a second distance smaller than the first distance. Therefore, a magnetic resistance of the second magnetic core is smaller than that of the first magnetic core in a magnetic circuit formed by the first and second magnetic cores. As a result, a disturbance magnetic field mainly passes through the second magnetic core.

Abstract: A bracket concave portion of a bracket is inserted into a vehicular jig concave portion of a vehicular jig, and a washer is put on a face of the bracket through an elastic member on a side opposite from a contact face of the bracket contacting the vehicular jig. The bracket is fixed by inserting a screw into a washer screw hole, an elastic member screw hole, a bracket screw hole and an attachment member screw hole from a side of the washer opposite from a contact face of the washer contacting the bracket. Thus, vibration of the bracket can be damped economically.

Abstract: A receiver of an ultrasonic sensor includes reception elements, each of which has a shape of a flat rectangular plate. The reception elements are arranged one-dimensionally on a plane so that the reception surfaces face the same direction and that the reception elements are aligned with small intervals in the width direction thereof while longitudinal ends of the reception elements at a certain side are aligned in a straight line. The widths and the thicknesses of the reception elements are even, while the longitudes of the reception elements are uneven. The both longitudinal ends of the reception elements are fixed to prohibit the vibration of the ends. The longitudes are designed so that the primary resonance frequencies of the reception elements are uneven.

Abstract: A current sensor includes a first magnetic core that surrounds a portion of a conductor as a current path and has gaps therein, each of which is defined by adjacent ends spaced from each other by a first distance, a magnetic sensing element placed in at least one of the gaps, and a second magnetic core placed near the surrounded portion of the conductor to divide the conductor into channels. The second magnetic core is spaced from the first magnetic core by a second distance smaller than the first distance. Therefore, a magnetic resistance of the second magnetic core is smaller than that of the first magnetic core in a magnetic circuit formed by the first and second magnetic cores. As a result, a disturbance magnetic field mainly passes through the second magnetic core.

Abstract: A current sensor for measuring an electric current flowing through a current bus bar includes: a magnetic core with an opening, through which the current bus bar passes with a predetermined interval; and a first magnetic sensor for detecting magnetic flux density in the magnetic core, the magnetic flux density generated by the electric current passing through the current bus bar. The magnetic core has a first gap and a second gap. The first magnetic sensor is disposed in the first gap. The second gap is capable of preventing magnetic saturation of the magnetic core.

Abstract: A ring type current sensor has a C-shaped core and a magnetic sensor. An inner circumference of the core defines a detection field of a current. Both end faces in a circumferential direction of the core forms a gap therebetween. A cross-sectional area of the core perpendicular to the circumferential direction gradually increases from the both end faces to a portion opposite to the gap in a diametrical direction. A magnetic sensor is disposed in the gap. Preferably, the core is a stack of a plurality of core plates having different shapes.

Abstract: An ultrasonic element has a membrane formed as a thin walled portion of a substrate, on which a piezoelectric vibrator is formed. The piezoelectric vibrator comprises a piezoelectric thin film and metal electrode films, which are formed into a sandwiched structure. The piezoelectric vibrator resonates with the membrane at a predetermined ultrasonic wave-band frequency. A hollow-out pattern is formed in the piezoelectric thin film to divide the piezoelectric vibrator into multiple portions, wherein the hollow-out pattern is formed in such an area corresponding to stress concentrated area which appears in vibrations of the membrane in diametrical directions thereof. The membrane is made to be easily deformed in response to vibration of the piezoelectric vibrator, so that an ultrasound of a higher sound pressure can be emitted.

Abstract: A receiver of an ultrasonic sensor includes reception elements, each of which has a shape of a flat rectangular plate. The reception elements are arranged one-dimensionally on a plane so that the reception surfaces face the same direction and that the reception elements are aligned with small intervals in the width direction thereof while longitudinal ends of the reception elements at a certain side are aligned in a straight line. The widths and the thicknesses of the reception elements are even, while the longitudes of the reception elements are uneven. The both longitudinal ends of the reception elements are fixed to prohibit the vibration of the ends. The longitudes are designed so that the primary resonance frequencies of the reception elements are uneven.

Abstract: A portable power working machine is disclosed, which is capable of effectively minimizing the clogging of the air cleaner, thereby dispensing with frequent maintenance. This portable power working machine comprises an air cleaner (30) having a base body case (32) provided with a clean air discharge port (33) for introducing the air cleaned into an intake port (25) of a carburetor (14), a filter (35) which is mounted on a filter mounting opening (32a) of base body case (32) so as to seal it, and a cleaner cover (37) which is attached onto the filter (35) so as to cover the filter (35) and to guide outside air toward the filter (35), while giving a predetermined directionality to the outside air.

Abstract: A current sensor for measuring an electric current flowing through a current bus bar includes: a magnetic core with an opening, through which the current bus bar passes with a predetermined interval; and a first magnetic sensor for detecting magnetic flux density in the magnetic core, the magnetic flux density generated by the electric current passing through the current bas bar. The magnetic core has a first gap and a second gap. The first magnetic sensor is disposed in the first gap. The second gap is capable of preventing magnetic saturation of the magnetic core.

Abstract: A ring type current sensor has a C-shaped core and a magnetic sensor. An inner circumference of the core defines a detection field of a current. Both end faces in a circumferential direction of the core forms a gap therebetween. A cross-sectional area of the core perpendicular to the circumferential direction gradually increases from the both end faces to a portion opposite to the gap in a diametrical direction. A magnetic sensor is disposed in the gap. Preferably, the core is a stack of a plurality of core plates having different shapes.

Abstract: A portable power working machine is disclosed, which is capable of effectively minimizing the clogging of the air cleaner, thereby dispensing with frequent maintenance. This portable power working machine comprises an air cleaner (30) having a base body case (32) provided with a clean air discharge port (33) for introducing the air cleaned into an intake port (25) of a carburetor (14), a filter (35) which is mounted on a filter mounting opening (32a) of base body case (32) so as to seal it, and a cleaner cover (37) which is attached onto the filter (35) so as to cover the filter (35) and to guide outside air toward the filter (35), while giving a predetermined directionality to the outside air.