Wireless communication function-equipped temperature sensor unit of railcar bogie
A wireless communication function-equipped temperature sensor unit includes: a temperature sensor; a wireless communication board including a conversion substrate including a conversion circuit configured to convert an analog temperature signal into a digital temperature signal, the analog temperature signal being output from the temperature sensor, and a wireless communication module mounted on the conversion substrate and configured to transmit the digital temperature signal as a wireless signal.
1. A wireless communication function-equipped temperature sensor unit attached to a box accommodating a rotating body of a railcar bogie, the wireless communication function-equipped temperature sensor unit comprising:
a temperature sensor;
a wireless communication board including
a conversion substrate including a conversion circuit configured to convert an analog temperature signal into a digital temperature signal, the analog temperature signal being output from the temperature sensor, and
a wireless communication module mounted on the conversion substrate and configured to transmit the digital temperature signal as a wireless signal,
the wireless communication board being arranged away from the temperature sensor and located at a side of the temperature sensor, the side being opposite to a side where the rotating body is arranged;
a battery arranged between the temperature sensor and the wireless communication board and configured to supply electric power to the wireless communication board; and
a housing accommodating the temperature sensor, the wireless communication board, and the battery and attached to the box,
the wireless communication board being arranged along a tangential direction of the rotating body, with the proviso that a main surface of the wireless communication board faces an outer peripheral surface of the rotating body,
the temperature sensor, the battery, and the wireless communication board being arranged so as to overlap one another when viewed from a normal direction of the wireless communication board.
2. The wireless communication function-equipped temperature sensor unit according to claim 1 , wherein the housing includes:
a base plate attached to the box and configured to transfer heat to the temperature sensor, the base plate being made of metal; and
a cover attached to the base plate and covering the temperature sensor, the wireless communication board, and the battery, the cover being made of an electrically nonconductive material.
3. The wireless communication function-equipped temperature sensor unit according to claim 2 , further comprising a thermal conduction sheet sandwiched between the base plate and the temperature sensor and having an electric insulation property.
4. The wireless communication function-equipped temperature sensor unit according to claim 3 , wherein the base plate includes a concave portion accommodating the thermal conduction sheet, the concave portion being located on a surface of the base plate, the surface facing the temperature sensor.
5. A wireless communication function-equipped temperature sensor unit attached to a box accommodating a rotating body of a railcar bogie, the wireless communication function-equipped temperature sensor unit comprising:
a temperature sensor;
a wireless communication board including
a conversion substrate including a conversion circuit configured to convert an analog temperature signal into a digital temperature signal, the analog temperature signal being output from the temperature sensor, and
a wireless communication module mounted on the conversion substrate and configured to transmit the digital temperature signal as a wireless signal,
the wireless communication board being arranged away from the temperature sensor and located at a side of the temperature sensor, the side being opposite to a side where the rotating body is arranged;
a battery arranged between the temperature sensor and the wireless communication board and configured to supply electric power to the wireless communication board;
a housing accommodating the temperature sensor, the wireless communication board, and the battery and attached to the box; and
a sensor substrate on which the temperature sensor is mounted, the sensor substrate including a sensor circuit configured to output the analog temperature signal to the conversion circuit, wherein:
the wireless communication board is arranged along a tangential direction of the rotating body;
the temperature sensor, the battery, and the wireless communication board are arranged so as to overlap one another when viewed from a normal direction of the wireless communication board;
the sensor substrate is arranged between the temperature sensor and the battery so as to face in the same direction as the wireless communication board; and
the temperature sensor, the sensor substrate, the battery, and the wireless communication board are arranged so as to overlap one another when viewed from the normal direction of the wireless communication board.
6. The wireless communication function-equipped temperature sensor unit according to claim 5 , further comprising an electrically nonconductive spacer arranged between the sensor substrate and the wireless communication board, wherein
the battery is provided in a space formed by the spacer and accommodated in a holder provided at the wireless communication board.
7. The wireless communication function-equipped temperature sensor unit according to claim 1 , wherein a size of the battery in a direction along the wireless communication board is larger than a size of the battery in a thickness direction of the wireless communication board.
8. A wireless communication function-equipped temperature sensor unit attached to a box accommodating a rotating body of a railcar bogie, the wireless communication function-equipped temperature sensor unit comprising:
a temperature sensor;
a wireless communication board including
a conversion substrate including a conversion circuit configured to convert an analog temperature signal into a digital temperature signal, the analog temperature signal being output from the temperature sensor, and
a wireless communication module mounted on the conversion substrate and configured to transmit the digital temperature signal as a wireless signal,
the wireless communication board being arranged away from the temperature sensor and located at a side of the temperature sensor, the side being opposite to a side where the rotating body is arranged;
a battery arranged between the temperature sensor and the wireless communication board and configured to supply electric power to the wireless communication board; and
a housing accommodating the temperature sensor, the wireless communication board, and the battery and attached to the box, wherein:
the wireless communication board is arranged along a tangential direction of the rotating body;
the temperature sensor, the battery, and the wireless communication board are arranged so as to overlap one another when viewed from a normal direction of the wireless communication board;
the rotating body is a bearing supporting an axle;
the box is an axle box accommodating the bearing; and
the housing includes a circular-arc heat receiving surface configured to transfer heat to the temperature sensor, the circular-arc heat receiving surface being in surface contact with an outer peripheral surface of an outer ring of the bearing.
9. The wireless communication function-equipped temperature sensor unit according to claim 1 , wherein:
the housing includes a contact member; and
the contact member is in surface contact with the outer peripheral surface of the rotating body and is configured to transfer heat to the temperature sensor.
10. The wireless communication function-equipped temperature sensor unit according to claim 9 , wherein the contact member includes a circular-arc heat receiving surface which is in surface contact with the outer peripheral surface of the rotating body.