Induction Heating Head

• US 20140231415A1
• Filed: 02/19/2013
• Published: 08/21/2014
• Est. Priority Date: 02/19/2013
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Verhagen, Paul D., Carter, Tiffany Anne, Sherrill, Alan Dale
• Granted Patent: US 10,645,763 B2
• Time in Patent Office: Days
• US Class Current: 219/660
• CPC Class Codes: H05B 6/101 for local heating of metal pieces
• CPC Class Codes: H05B 6/14 Tools, e.g. nozzles, rollers, calenders
• CPC Class Codes: H05B 6/365 using supplementary conductive or ferromagnetic pieces
• CPC Class Codes: H05B 6/42 Cooling of coils
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

An induction heating system includes a power source and an induction head. The converter output is at a voltage that is not greater than the voltage applied to the coil. The induction head includes a housing that houses a conductive coil disposed to induce heat in a workpiece and the coil is wound to be tuned to the output power. The coil is wound in a stacked spiral pattern with at least two turns in each layer. A flux concentrator is disposed about the coil with a potting compound around the concentrator and coil. Spacers maintain a desired separation between the head and the workpiece. The coil is a tube carrying a coolant. The head includes a wear surface that prevents contact of the coil and the workpiece, and a thermal insulator between the coil and wear surface. A non-contact temperature sensor is mounted to the housing.

Claims

1. An induction heating head comprising a conductive coil, wherein the conductive coil is wound in a stacked pancake spiral pattern having at least two layers and at least two turns in each layer.

2. The induction heating head of claim 1, further comprising, a flux concentrator, disposed about the conductive coil, whereby the flux is concentrated toward a first face of the induction head, and wherein the conductive coil is held in a fixed position with respect to the flux concentrator, and wherein the first face is comprised of a wear surface disposed to prevent the coil from contacting the workpiece, and a thermal insulator disposed between the coil and the wear surface.

3. The induction heating head of claim 2, wherein each layer has at least four turns and the conductive coil is a copper tube that carries a coolant.

4. The induction heating head of claim 1, wherein each layer has a number of turns chosen to tune the head to a power source.

5. The induction heating head of claim 4, wherein the housing includes at least one spacer disposed to maintain a desired separation between the first face and a workpiece.

6. The induction heating head of claim 5, further comprising a temperature sensor mounted to the housing.

7. The induction heating head of claim 6, wherein the temperature sensor is a non-contact temperature sensor.

8. An induction heating head, having a first face disposed to be held near a workpiece to be heated, comprising:

a conductive coil;

a plurality of spacers mounted to the housing disposed to maintain a desired separation between the first face and the workpiece.

9. The induction heating head of claim 8, further comprising a flux concentrator, disposed about the conductive coil, wherein the conductive coil is held in a fixed position with respect to the flux concentrator, and whereby the flux is concentrated toward the first face.

10. The induction heating head of claim 9, wherein the conductive coil is comprised of copper and is wound in a stacked spiral pattern having two layers and at least two turns in each layer, and the copper coil is a tube that carries a coolant.

11. The induction heating head of claim 10, wherein each layer has a number of turns chosen to tune the head to power source.

12. The induction heating head of claim 11, further comprising a non-contact temperature sensor mounted to the housing.

13. The induction heating head of claim 8, wherein the first face comprises at least one of a thermal insulator and a wear surface disposed to prevent contact of the coil and the workpiece, and further comprising a handle, mounted to the housing, whereby the induction head can be held while it is being used to heat.

14. An induction heating system, comprising:

a switched power source having a converter that provides a converter output of at least 1 KW at an RMS converter voltage; and

an induction head, coupled to the power output to receive the converter output at the RMS converter voltage, wherein the induction head includes a housing, and, within the housing, a conductive coil disposed to induce heat in a workpiece and wound to be tuned to the output power, whereby the conductive coil receives the RMS converter voltage without the RMS converter voltage being transformed to a lower voltage.

15. The induction heating system of claim 14 wherein the conductive at least two turns in each layer, such that the copper coil is tuned to the power output, and wherein the induction head further comprises a flux concentrator, disposed about the copper coil, whereby the flux is concentrated toward a first face of the induction head.

16. The induction heating system of claim 15, wherein the coil and the flux concentrator are disposed in the housing.

17. The induction heating system of claim 16, wherein the housing includes at least one spacer disposed to maintain a desired separation between the first face and the workpiece.

18. The induction heating system of claim 17, further comprising a non-contact temperature sensor mounted to the housing, wherein the temperature sensor provides feedback to the power source.

19. The induction heating system of claim 15, wherein the first face comprises a wear surface disposed to prevent contact of the coil and the workpiece, and a thermal insulator disposed between the coil and the wear surface and further comprising a handle, mounted to the housing, whereby the induction head can be held while it is being used to heat.

20. An induction heating head comprising a conductive coil, wherein the conductive coil is wound in a pancake spiral pattern having at least one layer and at least two turns in each layer, and wherein each layer has a number of turns chosen to tune the head to a power source.