Title:
STEEL BAR FLAW DETECTING DEVICE
Document Type and Number:
WIPO Patent Application WO/2002/021117
Kind Code:
A1
Abstract:
A steel bar flaw detecting device capable of inspecting high-temperature steel bars at high speeds. A pre-treating unit (31), a detecting unit (32) and a post-treating unit (33) are disposed along the traveling axis of steel bars, the pre-treating unit and the post-treating unit having the same structure with dc windings (312, 332) externally wound around sleeves (311, 331) respectively. Each steel bar is magnetically saturated by a dc magnetic field, and an eddy current is generated on the surface of a steel bar by an ac winding (321) of a detection unit (12). A change in magnetic field caused by the eddy current is detected by detection windings (322, 323). An intensity of a dc magnetic field is flattened along the traveling axis of steel bars due to sleeves made of a non-magnetic material to restrict noise to be produced by a change in a dc magnetic field intensity even when steel bars are moved at high speeds.
Inventors:
FUJISAKI KEISUKE (JP)
TOMITA KAZUOMI (JP)
TOMITA KAZUOMI (JP)
Application Number:
PCT/JP2001/007707
Publication Date:
March 14, 2002
Filing Date:
September 05, 2001
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
FUJISAKI KEISUKE (JP)
TOMITA KAZUOMI (JP)
FUJISAKI KEISUKE (JP)
TOMITA KAZUOMI (JP)
International Classes:
G01N27/90; (IPC1-7): G01N27/90
Foreign References:
| JPS58102150A | 1983-06-17 | |||
| JPS5984404A | 1984-05-16 |
Other References:
KOZUOMI TOMITA ET AL.: "Multi-channel karyuu tanshou souchi no kaihatsu", ZAIRYOU TO PROCESS, vol. 6, no. 5, September 1993 (1993-09-01), pages 1235, XP002947309
Attorney, Agent or Firm:
Ishida, Takashi (ISHIDA & ASSOCIATES Toranomon 37 Mori
Bldg. 5-, Toranomon 3-chome Minato-ku Tokyo, JP)
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