| 摘要 |
PURPOSE:To make it possible to detect the phenomena concerning a tire by a compact, light-weight, inexpensive sensor without a power source, by combining a piezoelectric element and a transmitter, which transmits voltage pulses generated in the piezoelectric element, through an elastic body, and embedding them in the tire. CONSTITUTION:A monitoring sensor 1 comprises a piezoelectric element 3 or a combined body of the element and a mass body 5, which amplifies the deformation of the element; and a transmitter 6, which transmits voltages pulses generated by the piezoelectric element 3. Both parts are electrically connected through an elastic body 7. The sensor is embedded in the outer surface of tire 8, with the tip of the mass body 5 directed outward. At the time of the normal rotation, output pulses 9 with a constant interval are converted into an electromagnetic wave by the transmitter 6 and displayed on a display device in a vehicle, when the rotation of the tire is started. When the pressure in the tire is decreased, peculiar pulses 10 are displayed. When the abrasion of the tire reaches the limit, extremely high pulses 11 are displayed. Thus, the phenomena of the tire can be detected by the compact sensor at low costs without power source. |
