IP Library Granted Patent US 10,739,311
Granted Patent B2
US 10,739,311 · App. 16/313,729 · Granted Aug 11, 2020

Rail inspection system

Inventors: Ryuzo Kawabata (Tokyo, JP); Akihiko Kandori (Tokyo, JP)
Assignee: HITACHI HIGH-TECH FINE SYSTEMS CORPORATION
G01N27/72B61K9/08G01R33/12G01N2291/0234G01N2291/2623
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Quick Facts
Patent No.
US 10,739,311
App. No.
16/313,729
Granted
Aug 11, 2020
Kind
B2
Abstract

In a rail inspection system, a positional deviation can be detected with accuracy. The rail inspection system includes a first sensor unit which is disposed to face a rail for a vehicle, and includes at least one receiver coil and at least one oscillation coil which are arranged in an arrangement direction intersecting with a layout direction of the rail, an AC voltage source which applies AC voltage to the oscillation coil, and a displacement detection unit which detects a displacement between the rail and the first sensor unit based on an induced voltage of the receiver coil. The first sensor unit is configured such that, when the displacement is a first displacement, a first maximum value appears in the induced voltage, and when the displacement is a second displacement, a second maximum value of which a phase is reversed against the first maximum value appears in the induced voltage.

Claims (16)

1. A rail inspection system, comprising:

a first sensor unit which is disposed to face a rail for a vehicle, and includes at least one receiver coil and at least one oscillation coil which are arranged in an arrangement direction intersecting with a layout direction of the rail;

an AC voltage source which applies an AC voltage to the oscillation coil;

a displacement detection unit which detects a displacement between the rail and the first sensor unit based on an induced voltage of the receiver coil, wherein

the first sensor unit is configured such that, when the displacement is a first displacement, a first maximum value appears in the induced voltage, and when the displacement is a second displacement, a second maximum value of which a phase is reversed against the first maximum value appears in the induced voltage wherein

the first sensor unit includes a first oscillation coil, a first receiver coil, and a second oscillation coil which are arranged along the arrangement direction, and

the AC voltage source applies the AC voltage to the first oscillation coil and the second oscillation coil such that a reverse magnetic field is generated.

2. The rail inspection system according to claim 1 , further comprising:

a second sensor unit which is disposed to face the first sensor unit along the layout direction, wherein

the second sensor unit includes a third oscillation coil which faces the first oscillation coil along the layout direction, a second receiver coil which faces the first receiver coil along the layout direction, and a fourth oscillation coil which faces the second oscillation coil along the layout direction, and

the AC voltage source applies the AC voltage to the third oscillation coil and the fourth oscillation coil to cause the third oscillation coil to generate a magnetic field of the same direction as the second oscillation coil, and to cause the fourth oscillation coil to generate a magnetic field of the same direction as the first oscillation coil.

3. The rail inspection system according to claim 2 , wherein

a gap between the first oscillation coil and the third oscillation coil is larger than a diameter of the first oscillation coil.

4. The rail inspection system according to claim 1 , further comprising:

a second sensor unit which is disposed to face the rail, and includes at least one receiver coil and at least one oscillation coil which are arranged in an arrangement direction intersecting with the layout direction, wherein

a distance between the second sensor unit and the rail is longer than a distance between the first sensor unit and the rail.

Assignments (4)
COMPANY SPLIT Recorded Sep 9, 2025
From: HITACHI HIGH-TECH SOLUTIONS CORPORATION
To: HITACHI HIGH-TECH CORPORATION
Reel/Frame 072888/0801 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 21, 2022
From: HITACHI HIGH-TECH CORPORATION
To: HITACHI HIGH-TECH SOLUTIONS CORPORATION
Reel/Frame 060261/0488 →
MERGER Recorded Jun 21, 2022
From: HITACHI HIGH-TECH FINE SYSTEMS CORPORATION
To: HITACHI HIGH-TECH CORPORATION
Reel/Frame 060546/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 4, 2019
From: KAWABATA, RYUZO; KANDORI, AKIHIKO
To: HITACHI HIGH-TECH FINE SYSTEMS CORPORATION
Reel/Frame 047904/0169 →
Cited By (2)
US 12,570,336 US 12,623,695