Looseness detection sensor and method
AssigneeNippon Telegraph and Telephone Corporation
InventorsEri Matsunaga, Tadashi Minotani, Masahito Nakamura, Masayuki Tsuda
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Abstract
A looseness detection sensor for detecting looseness of a bolt for fixing a component, including: a resonance unit arranged adjacent to a head portion of the bolt and made of an insulating material confining a high-frequency signal input externally; and a conductive member in conduction with the component across the resonance unit, wherein the conductive member is a cap put on the head portion of the bolt and includes a protrusion contacting a surface of the component.
Claims6
A looseness detection sensor for detecting looseness of a bolt for fixing a component, the looseness detection sensor comprising:
- a resonance unit arranged adjacent to a head portion of the bolt and made of an insulating material confining a high-frequency signal input externally;
- and
- a conductive member in conduction with the component across the resonance unit,
- wherein the conductive member is a cap put on the head portion.
A looseness detection sensor for detecting looseness of a bolt for fixing a component, the looseness detection sensor comprising:
- a resonance unit arranged adjacent to a head portion of the bolt and made of an insulating material confining a high-frequency signal input externally;
- and
- a conductive member in conduction with the component across the resonance unit,
- wherein the conductive member comprises a protrusion contacting a surface of the component or the head portion.
A looseness detection method performed by a looseness detection device for detecting looseness of a bolt for fixing a component, the looseness detection method comprising:
- a sensor attachment step of attaching, to a head portion of the bolt, a looseness detection sensor comprising a resonance unit arranged adjacent to the head portion and made of an insulating material confining a high-frequency signal input externally and a conductive member in conduction with the component across the resonance unit, wherein the conductive member is a cap put on the head portion;
- a reflected wave reception step of sweeping and applying a high-frequency signal in a predetermined range of frequencies to the looseness detection sensor and receiving a reflected wave of the high-frequency signal;
- a peak value record step of recording a peak value of the reflected wave;
- a comparison step of comparing the peak value and a previous peak value and calculating an amount of change;
- and
- a determination step of determining that the looseness does not occur when the amount of change is less than a threshold and determining that the looseness occurs when the amount of change is greater than or equal to the threshold.
Dependencies are inferred from the claim text.