Title:
TRANSMITTER FOR DETECTING IN-PIPE MOBILE BODY, IN-PIPE MOBILE BODY, AND SYSTEM FOR DETECTING IN-PIPE MOBILE BODY
Document Type and Number:
WIPO Patent Application WO/2012/123993
Kind Code:
A1
Abstract:
The transmitter (4) of a pig detection system (6) is provided with a permanent magnet (12) and a motor (131) which rotates the permanent magnet (12) in such a manner that the magnetic pole surface (12a) of the permanent magnet (12) moves in the circumferential direction about a rotation axis (L1) which is parallel to the axis (1A) of a pipe (1). When the motor (131) rotates, a rotating magnetic field which rotates in a perpendicular plane (A) perpendicular to the rotation axis (L1) and which is centered on the rotation axis (L1) is generated by the transmitter (4). The rotating magnetic field includes a magnetic field vector (V1) which is directed outward of the pipe (1) and which is present in the perpendicular plane (A) perpendicular to the axis (1A) of the pipe (1). The position of a pig (2) can be accurately specified from the outside of the pipe (1) on the basis of the magnetic field vector (V1). Because the rotating magnetic field includes a frequency component, the rotating magnetic field generated by the transmitter (4) and a disturbance magnetic field, such as earth's magnetism, can be discriminated from each other utilizing the frequency component.
Inventors:
SHIMIZU SHIGEJIRO (JP)
Application Number:
PCT/JP2011/001586
Publication Date:
September 20, 2012
Filing Date:
March 17, 2011
Export Citation:
Assignee:
SHIMIZU SHIGEJIRO (JP)
International Classes:
G01B7/00; F16L55/26
Foreign References:
| JPS57133373A | 1982-08-18 | |||
| JPH02176089A | 1990-07-09 | |||
| JP2011033609A | 2011-02-17 | |||
| JPH11503630A | 1999-03-30 | |||
| JPS6117901A | 1986-01-25 | |||
| JPH11319106A | 1999-11-24 |
Attorney, Agent or Firm:
YOKOZAWA, Shiro (JP)
Shiro Yokozawa (JP)
Shiro Yokozawa (JP)
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Claims: