| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and device for detecting foreign matter in a tire capable of easily finding a magnetic metal piece buried in the vicinity of the surface layer of the tire as the foreign matter, a tire inspection device, and a tire molding machine and a tire uniformity machine provided with the inspection device. SOLUTION: This device for detecting the foreign matter in a tire comprises a sensor unit 1 including a magnetic sensor 10 composed of magnetic resistance elements 11 and 12, the electric resistances of which are changed in conformation to the quantity of cross flux, and a variable resistance element 13 provided so as to form a bridge circuit with the magnetic resistance elements 11 and 12. A main unit 5 comprises a differential amplifier 2, a determination circuit 3, and a power source 4. The voltage from the power source 4 is applied to two input temrinals of the bridge circuit, and the output of the bridge circuit is inputted to a non-inverting input terminal and an inverting input terminal of the differential amplifier 2. The determination circuit 3 determines the presence of the magnetic metal piece in the vicinity of the magnetic sensor 10, when the value of the voltage outputted from the differential amplifier 2 is larger than a predetermined reference value, and outputs the determination result. COPYRIGHT: (C)2005,JPO&NCIPI
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