Induction heating coil, and an apparatus and method for manufacturing a worked member

Patent metadata

Field	Value
Publication number	US-9604272-B2
Application number	US-201213542883-A
Country	US
Kind code	B2
Filing date	Jul 6, 2012
Priority date	Jan 6, 2010
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

An induction heating coil for stably heating a steel tube which is being fed in its axial direction without rotating, the heating being uniform in the circumferential direction and in a narrow range in the axial direction has at least two 1-turn coils in the form of a first turn coil body and a second turn coil body. The inner peripheral length Ln (the non-effective coil length) where the effective number of coil turns is less than the total number of coil turns when the coil is projected in the axial direction and the inner peripheral length L 0 of the projected coil bodies (the inner coil length) satisfy Ln/L 0 <0.05. First and second coil bodies have insulating portions on their connecting portions, and the insulating portions are present in locations separated by a central angle of 5-45° measured from the center of the coil bodies.

First claim

The invention claimed is:

1. A heating coil for carrying out induction heating of an elongated metal material while undergoing relative movement to an axial direction of the metal material with respect to the metal material without rotation of the metal material, the heating coil having at least a first 1-turn coil body which surrounds an outer periphery of the metal material in a circumferential direction and is spaced from the metal material and which has a first electrically insulating portion and a first electrical conductor, a second 1-turn coil body which is disposed in parallel with the first 1-turn coil body in the axial direction of the metal material and is spaced from the metal material and which substantially has the same shape and same size as the first 1-turn coil body and has a second electrically insulating portion and a second electrical conductor, and a body connecting portion which connects a first adjoining portion which adjoins the first electrically insulating portion in the circumferential direction and a second adjoining portion which adjoins the second electrically insulating portion in the circumferential direction, the body connection portion including a bend therein,
characterized in that the first electrically insulating portion is disposed on a portion of the first 1-turn coil body in the circumferential direction and the second electrically insulating portion is disposed on a portion of the second 1-turn coil body in the circumferential direction and that when the first adjoining portion and the second adjoining portion are projected in a cross section which is perpendicular to a relative direction of movement of the induction heating coil with respect to the metal material, and when a non-effective coil length is Ln and the an inner coil length is L 0 , then Ln/L 0 is greater than zero and at most 0.05,
wherein the first electrically insulating portion and the second electrically insulating portion are not overlapped with each other when viewed from the axial direction.

2. A manufacturing apparatus for a worked member characterized by comprising:
an induction heating coil as set forth in claim 1 ;
a cooling mechanism for cooling a metal material which underwent induction heating by the induction heating coil while undergoing relative movement with respect to the metal material together with the induction heating coil, thereby forming in the metal material a high temperature portion which moves in the axial direction of the metal material; and
a working mechanism for applying a bending moment to the high temperature portion.

Assignees

• Okada Nobuhiro
• Tomizawa Atsushi
• Shimada Naoaki
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Okada Nobuhiro
• Tomizawa Atsushi
• Shimada Naoaki

Classifications

• H05B6/44

  having more than one coil or coil segment · CPC title

• C21D9/085

  Cooling or quenching · CPC title

• C21D11/00

  Process control or regulation for heat treatments · CPC title

• H05B6/104

  metal pieces being elongated like wires or bands · CPC title

• C21D9/08

  for tubular bodies or pipes · CPC title