Induction heating coil, induction heating device, and heating method

Patent metadata

Field	Value
Publication number	US-10285221-B2
Application number	US-201415022721-A
Country	US
Kind code	B2
Filing date	Sep 17, 2014
Priority date	Sep 17, 2013
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

An induction heating coil ( 3 ) has a primary coil ( 4 ) to which electric power is supplied and a ring-shaped secondary coil ( 5 ) forming a closed circuit. The primary coil ( 4 ) has a base-side portion that covers an outer periphery of the secondary coil ( 5 ) and a distal-side portion extending from the base-side portion in the center axis direction of the secondary coil ( 5 ) in a state in which the base-side portion covers the secondary coil ( 5 ). The opening width of the base-side portion is greater than the opening width of the distal-side portion. The secondary coil ( 5 ) is provided such that it can be inserted into and removed from the inside of the primary coil ( 4 ) from the base-side portion of the primary coil ( 4 ).

First claim

The invention claimed is:

1. An induction heating coil comprising:
a primary coil to which electric power is supplied; and
a ring-shaped secondary coil forming a closed circuit,
wherein the primary coil comprises a base-side portion that covers an outer periphery of the secondary coil and a distal-side portion extending from the base-side portion in a center axis direction of the secondary coil in a state in which the base-side portion covers the secondary coil, and an opening width of the base-side portion is greater than an opening width of the distal-side portion,
wherein the secondary coil is provided such that the secondary coil is removable inserted into the primary coil from the base-side portion of the primary coil, and
wherein the primary coil and the secondary coil are disposed such that at least part of a workpiece is accommodated between the distal-side portion of the primary coil and the secondary coil.

2. The induction heating coil according to claim 1 , wherein the secondary coil comprises a ring-shaped outer conductor portion and a ring-shaped inner conductor portion provided inside the outer conductor portion with a space being provided between the inner conductor portion and the outer conductor portion, and wherein the outer conductor portion and the inner conductor portion are connected to each other in series to form a closed circuit.

3. The induction heating coil according to claim 2 , wherein the inner conductor portion is connected to the outer conductor portion such that current flows through the inner conductor portion in a direction opposite to a direction in which the current flows through the outer conductor portion.

4. The induction heating coil according to claim 2 , wherein the secondary coil comprises at least one core member interposed between the outer conductor portion and the inner conductor portion.

5. The induction heating coil according to claim 1 , wherein the primary coil has a cylindrical shape.

6. The induction heating coil according to claim 5 , wherein the primary coil is a solenoid coil.

7. An induction heating device comprising:
the induction heating coil according to claim 1 ;
a power source unit configured to supply the electric power to the primary coil of the induction heating coil;
a workpiece supporting portion configured to support the workpiece and to move the workpiece relative to the primary coil to insert the workpiece into the primary coil from the base-side portion of the primary coil; and
a secondary coil supporting portion configured to support the secondary coil of the induction heating coil and to move the secondary coil relative to the primary coil to insert the secondary coil into the primary coil from the base-side portion of the primary coil.

8. A heating method for heating a workpiece having a relatively thick portion and relatively thin portions provided on both sides of the thick portion using an induction heating coil, the heating method comprising:
inserting the workpiece into a primary coil of the induction heating coil from a base-side portion of the primary coil that is adapted to cover an outer periphery of a ring-shaped secondary coil such that one of the thin portions of the workpiece is accommodated in a distal-side portion of the primary coil that extends from the base-side portion in a center axis direction of the secondary coil in a state in which the base-side portion covers the secondary coil, and such that the thick portion and the other thin portion of the workpiece are accommodated in the base-side portion of the primary coil;
inserting the secondary coil of the induction heating coil into the primary coil from the base-side portion of the primary coil such that the secondary coil is arranged between the base-side portion of the primary coil and the thin portion of the workpiece that is accommodated in the base-side portion such that the base-side portion of the primary coil covers the secondary coil; and
supplying the electric power to the primary coil to inductively heat the workpiece,
wherein the primary coil and the secondary coil are disposed such that at least part of the workpiece is accommodated between the distal-side portion of the primary coil and the secondary coil.

9. A secondary coil to be accommodated in a primary coil to which electric power is supplied, the secondary coil comprising:
a ring-shaped outer conductor portion; and
a ring-shaped inner conductor portion provided inside the outer conductor portion with a space located between the inner conductor portion and the outer conductor portion; and
at least one core member interposed in the space between the outer conductor portion and the inner conductor portion,
wherein the primary coil and the secondary coil are disposed such that at least part of a workpiece is accommodated between a distal-side portion of the primary coil and the secondary coil.

10. The induction heating coil according to claim 1 , wherein
the secondary coil comprises a ring-shaped outer conductor portion, a ring-shaped inner conductor portion provided inside the outer conductor portion with a space located between the inner conductor portion and the outer conductor portion, and at least one core member interposed in the space between the outer conductor portion and the inner conductor portion,
the ring-shaped outer conductor portion has four surfaces,
the ring-shaped inner conductor portion has four surfaces,
a first surface of the four surfaces of the ring-shaped outer conductor portion faces a first surface of the four surfaces the ring-shaped inner conductor portion, and
the at least one core member is interposed between the first surface of the outer conductor portion and the first surface of the inner conductor portion.

11. The induction heating coil according to claim 10 , wherein
the at least one core member covers the first surface of the inner conductor portion and a second surface of the four surfaces of the inner conductor portion that is adjacent to the first surface.

12. The induction heating coil according to claim 10 , wherein
the at least one core member covers the first surface of the inner conductor portion, a second surface of the four surfaces of the inner conductor portion that is adjacent to the first surface, and a third surface of the four surfaces of the inner conductor portion that is adjacent to the first surface.

13. The heating method according to claim 8 , wherein
the secondary coil comprises a ring-shaped outer conductor portion, a ring-shaped inner conductor portion provided inside the outer conductor portion with a space located between the inner conductor portion and the outer conductor portion, and at least one core member interposed in the space between the outer conductor portion and the inner conductor portion,
the ring-shaped outer conductor portion has four surfaces,
the ring-shaped inner conductor portion has four surfaces,
a first surface of the four surfaces of the ring-shaped outer conductor portion faces a first surface of the four surfaces the ring-shaped inner conductor portion, and
the at least one core member is interposed between the first surface of the outer conductor portion and the first surface of the inner conductor portion.

14. The heating method according to claim 13 , wherein
the at least one core member covers the first surface of the inner conductor portion and a second surface of the four surfaces of the inner conductor portion that is adjacent to the first surface.

15. The heating method according to claim 13 , wherein
the at least one core member covers the first surface of the inner conduct

Assignees

• Neturen Co Ltd

Inventors

• Yasutake Hidehiro
• Ikuta Fumiaki
• Fukazawa Kengo

Classifications

• H05B6/102

  the metal pieces being rotated while induction heated · CPC title

• H05B6/44

  having more than one coil or coil segment · CPC title

• H05B6/36

  Coil arrangements · CPC title

• H05B6/04 Primary

  Sources of current · CPC title

• H05B6/40 Primary

  Establishing desired heat distribution, e.g. to heat particular parts of workpieces · CPC title