Tendon diagnosis device using induced voltage measurement, and bridge cable diagnosis system using same

{
  "publication_number": "US12385879B2",
  "country": "US",
  "kind": "B2",
  "title": "Tendon diagnosis device using induced voltage measurement, and bridge cable diagnosis system using same",
  "abstract": "The present invention relates to: a device that applies an induced magnetic field to a tendon, measures changes that occur in the induced magnetic field due to damage to the tendon or changes in sectional force in the tendon, and/or measures the induced voltage induced by the changes in the induced magnetic field, and diagnoses the tendon; and a bridge cable diagnosis system using same.",
  "claims": [
    "1. A tendon diagnosis device comprising: a main body configured as a cylindrical member having a hollow portion and extending in a longitudinal direction; a search coil wound around the main body and configured to measure an induced voltage induced by a change in induced magnetic field; a plurality of magnetic field forming bodies each including a core member extending in the longitudinal direction, and a solenoid coil wound around an outer surface of the core member, the plurality of magnetic field forming bodies being configured to form the induced magnetic field; and end connection pieces respectively coupled to two opposite end surfaces of the main body based on the longitudinal direction, wherein the main body includes first and second half main bodies separated in a transverse direction, wherein the search coil includes first and second half search coils tightly installed while being wound around outer surfaces of the first and second half main bodies along circumferences of the first and second half main bodies, wherein the end connection pieces each include first and second half end connection pieces separated in the transverse direction, wherein the main body is installed to surround an outer portion of a tendon so that the tendon is positioned in the hollow portion of the main body, wherein the first and second half main bodies are coupled while surrounding the tendon in the transverse direction to define a cylindrical shape, wherein the first and second half search coils are electrically connected, wherein the first and second half end connection pieces are installed outside the tendon and coupled while surrounding the tendon in the transverse direction to define a circular ring, wherein in a state in which the induced magnetic field is formed by applying a voltage to the solenoid coils, the search coils measure the induced voltage induced by a change in sectional force of the tendon or a change in induced magnetic field caused by damage to the tendon while moving along the tendon, wherein two opposite ends of the core member of each of the magnetic field forming bodies are electromagnetically and continuously coupled to the end connection pieces so that magnetic force lines are induced to be concentrated in the hollow portion of the main body and flow along the tendon in the longitudinal direction, wherein vertical protruding portions protrude in a vertical direction from positions at which the first and second half search coils are installed at upper and lower circumferential edges of the first and second half main bodies based on the vertical direction, wherein electric wire passing holes, which are formed through the vertical protruding portions in the circumferential direction, are formed in portions of lower ends of the vertical protruding portions that are connected to the circumferential edges of the first and second half main bodies, wherein the ends of the first and second half search coils wound around the circumferences of the first and second half main bodies pass through the electric wire passing holes, extend in the vertical direction while being in close contact with inner surfaces of the vertical protruding portions, and are positioned while standing in the vertical direction along the inner surfaces of the vertical protruding portions, wherein the vertical protruding portions of the first and second half main bodies adjoin each other while facing each other when the first and second half main bodies are coupled, wherein the ends of the first and second half search coils, which are in close contact with the inner surfaces of the vertical protruding portions while standing uprightly, also face each other while maintaining a vertical state, wherein the first and second half search coils are electrically connected to each other outside the vertical protruding portions in a state in which planar member shapes defined by a plurality of electric wires of the first and second half search coils are positioned to extend in the longitudinal direction so as not to hinder the magnetic force lines flow in the longitudinal direction outside the main body, and wherein the search coil is formed in a shape in which the electric wires of the first and second half search coils are spirally wound in the circumferential direction around the main body configured as a continuously cylindrical member.",
    "2. The tendon diagnosis device of claim 1, wherein supports, which are provided in the form of a plurality of legs extending vertically downward, are provided on the outer surfaces of the first and second half main bodies, such that the tendon diagnosis device is stably placed on a floor without rolling in the transverse direction at the time of carrying, mounting, or storing the tendon diagnosis device.",
    "3. The tendon diagnosis device of claim 1, wherein electric connectors are provided at the ends of the first and second half search coils and electrically connect the first and second half search coils, wherein the electric connectors are installed on the vertical protruding portions, and wherein the electric connectors are fastened to each other when the first and second half main bodies are coupled, such that the first and second half search coils are electrically connected to constitute the search coil.",
    "4. The tendon diagnosis device of claim 1, wherein guide wheels are provided at two opposite ends of the main body based on the longitudinal direction, and wherein the guide wheels come into contact with the outer surface of the tendon when the tendon diagnosis device is installed on the tendon, the tendon diagnosis device is installed to be suspended from the tendon in a state in which an interval is automatically defined between an inner surface of the hollow portion of the main body and the outer surface of the tendon, and the tendon diagnosis device moves along the tendon.",
    "5. A bridge cable diagnosis system, which is configured to diagnose a bridge cable, the bridge cable diagnosis system comprising: a tendon diagnosis device according to claim 1; a traveling robot having a pulley around which a hoisting wire is wound to change a direction thereof, the traveling robot being fastened to the bridge cable and configured to move along the bridge cable and be fixed at a predetermined fixed position; and a winch coupled to one end of the hoisting wire and configured to move the tendon diagnosis device by pulling or releasing the hoisting wire, wherein the tendon diagnosis device is installed on the inclined bridge cable, wherein the traveling robot having the pulley is installed at a position on the bridge cable above the tendon diagnosis device, wherein the other end of the hoisting wire is coupled to the tendon diagnosis device, wherein one end of the hoisting wire extends toward the traveling robot and is wound around the pulley to change the direction thereof, and then the other end of the hoisting wire is coupled to the winch to define an initially installed state, and wherein the traveling robot is moved toward an upper side of the bridge cable and moved to a fixed position at a predetermined height, and then the winch operates to adjust tension of the hoisting wire to operate the tendon diagnosis device at a predetermined separated diagnosis position while moving the tendon diagnosis device to the predetermined separate diagnosis position to monitor and recognize a state of the tendon, such that the state of the bridge cable is diagnosed.",
    "6. The bridge cable diagnosis system of claim 5, wherein after the traveling robot is moved to the predetermined fixed position, a position of the traveling robot is fixed, the tendon diagnosis device is placed in a movable state, and the winch operates to impart tension to the hoisting wire and pull and hoist the tendon diagnosis device upward, such that the tendon diagnosis device is moved upward to the predetermined separate diagnosis position and operates to monitor a state of the tendon and diagnose a state of the bridge cable at the separate diagnosis position.",
    "7. The bridge cable diagnosis system of claim 5, wherein after the traveling robot is moved to the predetermined fixed position, a position of the traveling robot is fixed, the tendon diagnosis device is placed in a movable state, and the winch operates to impart tension to the hoisting wire and pull and hoist the tendon diagnosis device upward, such that after the tendon diagnosis device is moved to a predetermined diagnosis initiation position, the winch operates to adjust the tension of the hoisting wire, such that the tendon diagnosis device operates to monitor a state of the tendon and diagnose a state of the bridge cable in a state in which the tendon diagnosis device moved downward from the diagnosis initiation position is positioned at the predetermined separate diagnosis position."
  ],
  "description_excerpt": "The present invention relates to a device for diagnosing a state of a tendon and a system for diagnosing a state of a bridge cable configured by the tendon by using the device.\n\nIn general, a tendon includes a bundle of stranded tensioning wires to provide tension. The tendon is used for cables for a bridge or a tension member of prestressed concrete.\n\nIn general, tensile stress is applied to the tendon. The tendon is mainly used for a structurally important member. A change in stress applied to the tendon (sectional force of the tendon) due to corrosion or the like significantly affects performance of a structure member. Therefore, it is very important to measure the sectional force of the tendon. In addition, it is very important to recognize whether the sectional force of the tendon changes.\n\nKorean Patent No. 10-1590830 discloses a technology for measuring a change in sectional force of a tendon by applying a magnetic field to the tendon. The technology disclosed in Korean Patent No. 10-1590830 uses an inverse magnetostriction effect. Korean Patent No. 10-1851346 discloses a technology capable of installing a solenoid coil outside a tendon. Korean Patent No. 10-2178721 discloses a technology for detecting damage to a tendon. In the technology disclosed in Korean Patent No. 10-2178721, a magnetic field is applied to the tendon, and then induced voltage, which is generated by a change in magnetic field that occurs on a damaged portion of the tendon, is measured. Whether the tendon is damaged is recognized on the basis of the measured induced voltage.",
  "cpc": [
    "G01N 27/82",
    "B25J 5/02",
    "E01D 19/16",
    "G01N 27/83",
    "G01N 35/0099"
  ],
  "ipc": [
    "B25J 5/02",
    "G01N 27/82",
    "G01N 35/00"
  ],
  "assignees": [
    "Korea Institute of Civil Engineering and Building Technology KICT"
  ],
  "inventors": [
    "Ji-young Choi",
    "Hungjoo KWON",
    "Im-Jong KWAHK",
    "Changbin JOH",
    "Kwang-Yeun PARK",
    "Won-Jong CHIN"
  ],
  "filing_date": "2022-06-29",
  "publication_date": "2025-08-12",
  "grant_date": "2025-08-12",
  "priority_date": "2021-07-01",
  "application_number": "US-202218569974-A",
  "family_id": "77495118",
  "cited_by_count": 0,
  "citations": [
    "JP2556957Y2",
    "JP3545369B2",
    "KR101192286B1",
    "KR101590830B1",
    "KR101973067B1",
    "KR101851346B1",
    "US20200256832A1",
    "JP2020183897A",
    "CN110108790A",
    "KR102178721B1",
    "KR102292726B1"
  ]
}